CFGparadigms - User contributions [en]

Candida glabrata EPA7

2011-10-30T20:13:23Z

Kurt Drickamer: /* Biosynthesis of ligands */

'''Fungal adhesins with lectin properties''' 
Cell adhesion proteins on fungal cell surfaces mediate interactions both with other cells of the same type and with the external environment<ref>Douglas, L.M., Li, L., Yang, Y. and Dranginis, A.M. 2007. Expression and characterization of the flocculin Flo11/Muc1, a Saccharomyces cerevisiae mannoprotein with homotypic properties of adhesion. Eukaryot Cell, 6, 2214-2221.</ref><ref>Dranginis, A.M., Rauceo, J.M., Coronado, J.E. and Lipke, P.N. 2007. A biochemical guide to yeast adhesins: glycoproteins for social and antisocial occasions. Microbiol Mol Biol Rev, 71, 282-294.</ref>. These interactions impact critical processes including mating, pathogenesis, and biofilm formation. Fungal adhesins are typically GPI-anchored proteins that have been covalently linked to the cell wall, such that their N-terminal ligand binding domains extend from the cell surface. They frequently occur as families of related proteins<ref>Tronchin, G., Pihet, M., Lopes-Bezerra, L.M. and Bouchara, J.P. 2008. Adherence mechanisms in human pathogenic fungi. Med Mycol, 46, 749-772. </ref>. Members of two such groups, the flocculation/agglutination genes of the model yeast ''Saccharomyces cerevisiae''<ref>Kobayashi, O., Hayashi, N., Kuroki, R. and Sone, H. 1998. Region of FLO1 proteins responsible for sugar recognition. J Bacteriol, 180, 6503-6510.</ref> and the related EPA genes<ref>Kaur, R., Domergue, R., Zupancic, M.L. and Cormack, B.P. 2005. A yeast by any other name: Candida glabrata and its interaction with the host. Curr Opin Microbiol, 8, 378-384.</ref> of the pathogenic fungus ''Candida glabrata'', are lectins. Several of the 23 identified EPA genes have been functionally shown to mediate binding of ''C. glabrata'' to host cells<ref name="Castano 2005">Castano, I., Pan, S.J., Zupancic, M., Hennequin, C., Dujon, B. and Cormack, B.P. 2005. Telomere length control and transcriptional regulation of subtelomeric adhesins in Candida glabrata. Mol Microbiol, 55, 1246-1258.</ref><ref name="Domergue 2005">Domergue, R., Castano, I., de las Penas, A., Zupancic, M., Lockatell, V., Hebel, J.R. et al. 2005. Nicotinic acid limiation regulates silencing of Candida albicans adhesins during UTI. Science, 308, 866-870.</ref>, an essential step in infection and virulence. Defining the specificity of these proteins and their biological roles will elucidate the interactions between host and pathogen, and potentially indicate ways in which to inhibit them for the benefit of the host.

'''''Candida glabrata'' EPA7''' 
The EPA family was chosen as a paradigm because of its relevance to a fungal pathogen that affects human health that can be studied in mouse models of infection. EPA7 was chosen to represent this group because it has been demonstrated to function as an adhesin<ref name="Castano 2005"/> and is one of the EPA proteins that has been studied in the most detail. The N-terminal binding domain of this protein, expressed on the surface of S''. cerevisiae'', has been analyzed on the CFG glycan array. These studies demonstrated EPA7 binding specificity for β1,3- and β1,4-linked galactosides
<ref name=" Zupancic, M.L., 2008">
Zupancic, M.L., Frieman, M., Smith, D., Alvarez, R.A., Cummings, R.D. and Cormack, B.P. 2008. Glycan microarray analysis of Candida glabrata adhesin ligand specificity. Mol Microbiol, 68, 547-559.</ref><ref>de Groot, P.W.J. and Klis, F.M. 2008. The conserved PA14 domain of cell wall-associated fungal adhesins governs their glycan-binding specificity. Mol Microbiol, 68, 535-537. </ref>. This work represents a significant step forward in the area of lectin-like fungal adhesins; in general the specificity of these important proteins remains unexplored.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
* CFG Participating Investigators (PIs) who have contributed to studies of this paradigmatic protein include: Brendan Cormack, Rick Cummings
* PIs using CFG resources to study related ''S. cerevisiae'' proteins include: Lars-Oliver Essen (several flocculins), Peter Lipke (alpha agglutinin and ''Candida albicans'' Als adhesins)

== Progress toward understanding this GBP paradigm ==

=== Carbohydrate ligands ===

Carbohydrate ligands of Epa7 have been examined by glycan array analysis in work from the Cormack group <ref name=" Zupancic, M.L., 2008"></ref>and found to bind almost exclusively to non-reducing terminal β1-4 or β1-3-linked galactose residues. The Epa1 family member has similar specificity while Epa6 binds to most ligands with terminal galactose residues. The related ''S. cerevisiae'' flocculins bind α-mannose or α-glucose residues.

=== Cellular expression of GBP and ligands ===

EPA7 is expressed by the pathogenic fungus ''Candida glabrata''. The EPA gene family is subject to an interesting mechanism of regulation mediated by telomeric silencing. This silencing is relieved in low niacin, leading to increased protein expression. Because urine provides a low niacin growth environment, these adhesins are upregulated in precisely the niche where ''C. glabrata'' must adhere to cause urinary tract infections. 
Consistent with the site of ''C. glabrata'' infection, Epa6 and Epa7 mediate binding to uroepithelial cells in vitro <ref name="Castano 2005"></ref><ref name="Domergue 2005">Domergue, R., Castano, I., de las Penas, A., Zupancic, M., Lockatell, V., Hebel, J.R. et al. 2005. Nicotinic acid limiation regulates silencing of Candida albicans adhesins during UTI. Science, 308, 866-870.</ref>. It has also been noted <ref name=" Zupancic, M.L., 2008"></ref> that "Epa1, Epa6, and Epa7 recognize the T antigen Gal-β1-3GalNAc-α-R, one of the major mucin-type O-glycans found in the colonic epithelium", another site colonized by ''C. glabrata''. 

=== Biosynthesis of ligands ===
On mucins, the T (Galβ1-3GalNAcα1-Thr/Ser) target ligand for EPA7 is generated by the action of a family of polypeptide O-GalNAc transferases followed by addition of galactose by [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_447&sideMenu=true&pageType=general galactosyltransferase]. Transferases T1, T2, T3 and T4 have been suggested to be particularly important in colonic mucin glycosylation.
 

=== Structure ===

Epa proteins are C-type lectins, but no detailed structural information for these proteins is yet available.

=== Biological roles of GBP-ligand interaction ===

Epa7 and other Epa family members, as summarized above, participate in adhesion of the pathogenic yeast ''Candida glabrata'' cells to host cells, leading to infection. Related proteins participate in cell:cell interactions between yeast that can be important for critical processes such as mating or biofilm formation.

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=EPA7&maxresults=20 CFG database search results for "EPA7"].

=== Glycan profiling ===

Glycan profiling of host cell glycans has not been used in connection with this paradigm.

=== Glycogene microarray ===
Mammalian glycogene profiling has not been performed for this paradigm of a fungal protein. Although yeast binding to mammalian cells could conceivably trigger changes in glycogene expression, the critical issue for this adhesin is which glycans are present on the mammalian cell surface upon initial contact. These structures will mediate the cell:cell interactions that are important for establishment of infection.

=== Knockout mouse lines ===

CFG knockout mouse lines have not been used for studies pertaining to this paradigm. Examining ''C. glabrata'' infection using wild type and ''epa'' mutant strains in mice with defects in terminal galactosylation could potentially be of interest.

=== Glycan array ===
The specificity of Epa7 and related proteins was determined through CFG glycan array analysis<ref name=" Zupancic, M.L., 2008"></ref> (click [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1056 here] to see results). To see glycan array results for other EPA family members, click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=EPA&cat=coreh here]. Flocculins from ''S. cerevisiae'' have also been examined by CFG glycan array analysis (click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=flocculin&cat=coreh here]), and glycan array studies of flocculins from ''P. Pastoris'' and of additional ''Candida'' Epa domains have been approved.

== Related GBPs ==
* 22 additional EPA family members in ''C. glabrata''
* Related proteins in ''S. cerevisiae''
* EPA7-like glycan-binding domain also occurs in predicted proteins of ''Ashbya gossypii'' and ''Kluyveromyces lactis''.
(Click here for [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=EPA&maxresults=20 CFG data] on EPA family members)

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Richard Cummings, Tamara Doering, Peter Lipke

Candida glabrata EPA7

2011-10-30T19:25:25Z

Kurt Drickamer: /* Biosynthesis of ligands */

'''Fungal adhesins with lectin properties''' 
Cell adhesion proteins on fungal cell surfaces mediate interactions both with other cells of the same type and with the external environment<ref>Douglas, L.M., Li, L., Yang, Y. and Dranginis, A.M. 2007. Expression and characterization of the flocculin Flo11/Muc1, a Saccharomyces cerevisiae mannoprotein with homotypic properties of adhesion. Eukaryot Cell, 6, 2214-2221.</ref><ref>Dranginis, A.M., Rauceo, J.M., Coronado, J.E. and Lipke, P.N. 2007. A biochemical guide to yeast adhesins: glycoproteins for social and antisocial occasions. Microbiol Mol Biol Rev, 71, 282-294.</ref>. These interactions impact critical processes including mating, pathogenesis, and biofilm formation. Fungal adhesins are typically GPI-anchored proteins that have been covalently linked to the cell wall, such that their N-terminal ligand binding domains extend from the cell surface. They frequently occur as families of related proteins<ref>Tronchin, G., Pihet, M., Lopes-Bezerra, L.M. and Bouchara, J.P. 2008. Adherence mechanisms in human pathogenic fungi. Med Mycol, 46, 749-772. </ref>. Members of two such groups, the flocculation/agglutination genes of the model yeast ''Saccharomyces cerevisiae''<ref>Kobayashi, O., Hayashi, N., Kuroki, R. and Sone, H. 1998. Region of FLO1 proteins responsible for sugar recognition. J Bacteriol, 180, 6503-6510.</ref> and the related EPA genes<ref>Kaur, R., Domergue, R., Zupancic, M.L. and Cormack, B.P. 2005. A yeast by any other name: Candida glabrata and its interaction with the host. Curr Opin Microbiol, 8, 378-384.</ref> of the pathogenic fungus ''Candida glabrata'', are lectins. Several of the 23 identified EPA genes have been functionally shown to mediate binding of ''C. glabrata'' to host cells<ref name="Castano 2005">Castano, I., Pan, S.J., Zupancic, M., Hennequin, C., Dujon, B. and Cormack, B.P. 2005. Telomere length control and transcriptional regulation of subtelomeric adhesins in Candida glabrata. Mol Microbiol, 55, 1246-1258.</ref><ref name="Domergue 2005">Domergue, R., Castano, I., de las Penas, A., Zupancic, M., Lockatell, V., Hebel, J.R. et al. 2005. Nicotinic acid limiation regulates silencing of Candida albicans adhesins during UTI. Science, 308, 866-870.</ref>, an essential step in infection and virulence. Defining the specificity of these proteins and their biological roles will elucidate the interactions between host and pathogen, and potentially indicate ways in which to inhibit them for the benefit of the host.

'''''Candida glabrata'' EPA7''' 
The EPA family was chosen as a paradigm because of its relevance to a fungal pathogen that affects human health that can be studied in mouse models of infection. EPA7 was chosen to represent this group because it has been demonstrated to function as an adhesin<ref name="Castano 2005"/> and is one of the EPA proteins that has been studied in the most detail. The N-terminal binding domain of this protein, expressed on the surface of S''. cerevisiae'', has been analyzed on the CFG glycan array. These studies demonstrated EPA7 binding specificity for β1,3- and β1,4-linked galactosides
<ref name=" Zupancic, M.L., 2008">
Zupancic, M.L., Frieman, M., Smith, D., Alvarez, R.A., Cummings, R.D. and Cormack, B.P. 2008. Glycan microarray analysis of Candida glabrata adhesin ligand specificity. Mol Microbiol, 68, 547-559.</ref><ref>de Groot, P.W.J. and Klis, F.M. 2008. The conserved PA14 domain of cell wall-associated fungal adhesins governs their glycan-binding specificity. Mol Microbiol, 68, 535-537. </ref>. This work represents a significant step forward in the area of lectin-like fungal adhesins; in general the specificity of these important proteins remains unexplored.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
* CFG Participating Investigators (PIs) who have contributed to studies of this paradigmatic protein include: Brendan Cormack, Rick Cummings
* PIs using CFG resources to study related ''S. cerevisiae'' proteins include: Lars-Oliver Essen (several flocculins), Peter Lipke (alpha agglutinin and ''Candida albicans'' Als adhesins)

== Progress toward understanding this GBP paradigm ==

=== Carbohydrate ligands ===

Carbohydrate ligands of Epa7 have been examined by glycan array analysis in work from the Cormack group <ref name=" Zupancic, M.L., 2008"></ref>and found to bind almost exclusively to non-reducing terminal β1-4 or β1-3-linked galactose residues. The Epa1 family member has similar specificity while Epa6 binds to most ligands with terminal galactose residues. The related ''S. cerevisiae'' flocculins bind α-mannose or α-glucose residues.

=== Cellular expression of GBP and ligands ===

EPA7 is expressed by the pathogenic fungus ''Candida glabrata''. The EPA gene family is subject to an interesting mechanism of regulation mediated by telomeric silencing. This silencing is relieved in low niacin, leading to increased protein expression. Because urine provides a low niacin growth environment, these adhesins are upregulated in precisely the niche where ''C. glabrata'' must adhere to cause urinary tract infections. 
Consistent with the site of ''C. glabrata'' infection, Epa6 and Epa7 mediate binding to uroepithelial cells in vitro <ref name="Castano 2005"></ref><ref name="Domergue 2005">Domergue, R., Castano, I., de las Penas, A., Zupancic, M., Lockatell, V., Hebel, J.R. et al. 2005. Nicotinic acid limiation regulates silencing of Candida albicans adhesins during UTI. Science, 308, 866-870.</ref>. It has also been noted <ref name=" Zupancic, M.L., 2008"></ref> that "Epa1, Epa6, and Epa7 recognize the T antigen Gal-β1-3GalNAc-α-R, one of the major mucin-type O-glycans found in the colonic epithelium", another site colonized by ''C. glabrata''. 

=== Biosynthesis of ligands ===
On mucins, the T (Galβ1-3GalNAcα1-Thr/Ser) target ligand for EPA7 is generated by the action of a family of polypeptide O-GalNAc transferases followed by addition of galactose by galactosyltransferase. Transferases T1, T2, T3 and T4 have been suggested to be particularly important in colonic mucin glycosylation.
 

=== Structure ===

Epa proteins are C-type lectins, but no detailed structural information for these proteins is yet available.

=== Biological roles of GBP-ligand interaction ===

Epa7 and other Epa family members, as summarized above, participate in adhesion of the pathogenic yeast ''Candida glabrata'' cells to host cells, leading to infection. Related proteins participate in cell:cell interactions between yeast that can be important for critical processes such as mating or biofilm formation.

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=EPA7&maxresults=20 CFG database search results for "EPA7"].

=== Glycan profiling ===

Glycan profiling of host cell glycans has not been used in connection with this paradigm.

=== Glycogene microarray ===
Mammalian glycogene profiling has not been performed for this paradigm of a fungal protein. Although yeast binding to mammalian cells could conceivably trigger changes in glycogene expression, the critical issue for this adhesin is which glycans are present on the mammalian cell surface upon initial contact. These structures will mediate the cell:cell interactions that are important for establishment of infection.

=== Knockout mouse lines ===

CFG knockout mouse lines have not been used for studies pertaining to this paradigm. Examining ''C. glabrata'' infection using wild type and ''epa'' mutant strains in mice with defects in terminal galactosylation could potentially be of interest.

=== Glycan array ===
The specificity of Epa7 and related proteins was determined through CFG glycan array analysis<ref name=" Zupancic, M.L., 2008"></ref> (click [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1056 here] to see results). To see glycan array results for other EPA family members, click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=EPA&cat=coreh here]. Flocculins from ''S. cerevisiae'' have also been examined by CFG glycan array analysis (click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=flocculin&cat=coreh here]), and glycan array studies of flocculins from ''P. Pastoris'' and of additional ''Candida'' Epa domains have been approved.

== Related GBPs ==
* 22 additional EPA family members in ''C. glabrata''
* Related proteins in ''S. cerevisiae''
* EPA7-like glycan-binding domain also occurs in predicted proteins of ''Ashbya gossypii'' and ''Kluyveromyces lactis''.
(Click here for [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=EPA&maxresults=20 CFG data] on EPA family members)

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Richard Cummings, Tamara Doering, Peter Lipke

Candida glabrata EPA7

2011-10-30T19:24:47Z

Kurt Drickamer: /* Biosynthesis of ligands */

'''Fungal adhesins with lectin properties''' 
Cell adhesion proteins on fungal cell surfaces mediate interactions both with other cells of the same type and with the external environment<ref>Douglas, L.M., Li, L., Yang, Y. and Dranginis, A.M. 2007. Expression and characterization of the flocculin Flo11/Muc1, a Saccharomyces cerevisiae mannoprotein with homotypic properties of adhesion. Eukaryot Cell, 6, 2214-2221.</ref><ref>Dranginis, A.M., Rauceo, J.M., Coronado, J.E. and Lipke, P.N. 2007. A biochemical guide to yeast adhesins: glycoproteins for social and antisocial occasions. Microbiol Mol Biol Rev, 71, 282-294.</ref>. These interactions impact critical processes including mating, pathogenesis, and biofilm formation. Fungal adhesins are typically GPI-anchored proteins that have been covalently linked to the cell wall, such that their N-terminal ligand binding domains extend from the cell surface. They frequently occur as families of related proteins<ref>Tronchin, G., Pihet, M., Lopes-Bezerra, L.M. and Bouchara, J.P. 2008. Adherence mechanisms in human pathogenic fungi. Med Mycol, 46, 749-772. </ref>. Members of two such groups, the flocculation/agglutination genes of the model yeast ''Saccharomyces cerevisiae''<ref>Kobayashi, O., Hayashi, N., Kuroki, R. and Sone, H. 1998. Region of FLO1 proteins responsible for sugar recognition. J Bacteriol, 180, 6503-6510.</ref> and the related EPA genes<ref>Kaur, R., Domergue, R., Zupancic, M.L. and Cormack, B.P. 2005. A yeast by any other name: Candida glabrata and its interaction with the host. Curr Opin Microbiol, 8, 378-384.</ref> of the pathogenic fungus ''Candida glabrata'', are lectins. Several of the 23 identified EPA genes have been functionally shown to mediate binding of ''C. glabrata'' to host cells<ref name="Castano 2005">Castano, I., Pan, S.J., Zupancic, M., Hennequin, C., Dujon, B. and Cormack, B.P. 2005. Telomere length control and transcriptional regulation of subtelomeric adhesins in Candida glabrata. Mol Microbiol, 55, 1246-1258.</ref><ref name="Domergue 2005">Domergue, R., Castano, I., de las Penas, A., Zupancic, M., Lockatell, V., Hebel, J.R. et al. 2005. Nicotinic acid limiation regulates silencing of Candida albicans adhesins during UTI. Science, 308, 866-870.</ref>, an essential step in infection and virulence. Defining the specificity of these proteins and their biological roles will elucidate the interactions between host and pathogen, and potentially indicate ways in which to inhibit them for the benefit of the host.

'''''Candida glabrata'' EPA7''' 
The EPA family was chosen as a paradigm because of its relevance to a fungal pathogen that affects human health that can be studied in mouse models of infection. EPA7 was chosen to represent this group because it has been demonstrated to function as an adhesin<ref name="Castano 2005"/> and is one of the EPA proteins that has been studied in the most detail. The N-terminal binding domain of this protein, expressed on the surface of S''. cerevisiae'', has been analyzed on the CFG glycan array. These studies demonstrated EPA7 binding specificity for β1,3- and β1,4-linked galactosides
<ref name=" Zupancic, M.L., 2008">
Zupancic, M.L., Frieman, M., Smith, D., Alvarez, R.A., Cummings, R.D. and Cormack, B.P. 2008. Glycan microarray analysis of Candida glabrata adhesin ligand specificity. Mol Microbiol, 68, 547-559.</ref><ref>de Groot, P.W.J. and Klis, F.M. 2008. The conserved PA14 domain of cell wall-associated fungal adhesins governs their glycan-binding specificity. Mol Microbiol, 68, 535-537. </ref>. This work represents a significant step forward in the area of lectin-like fungal adhesins; in general the specificity of these important proteins remains unexplored.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
* CFG Participating Investigators (PIs) who have contributed to studies of this paradigmatic protein include: Brendan Cormack, Rick Cummings
* PIs using CFG resources to study related ''S. cerevisiae'' proteins include: Lars-Oliver Essen (several flocculins), Peter Lipke (alpha agglutinin and ''Candida albicans'' Als adhesins)

== Progress toward understanding this GBP paradigm ==

=== Carbohydrate ligands ===

Carbohydrate ligands of Epa7 have been examined by glycan array analysis in work from the Cormack group <ref name=" Zupancic, M.L., 2008"></ref>and found to bind almost exclusively to non-reducing terminal β1-4 or β1-3-linked galactose residues. The Epa1 family member has similar specificity while Epa6 binds to most ligands with terminal galactose residues. The related ''S. cerevisiae'' flocculins bind α-mannose or α-glucose residues.

=== Cellular expression of GBP and ligands ===

EPA7 is expressed by the pathogenic fungus ''Candida glabrata''. The EPA gene family is subject to an interesting mechanism of regulation mediated by telomeric silencing. This silencing is relieved in low niacin, leading to increased protein expression. Because urine provides a low niacin growth environment, these adhesins are upregulated in precisely the niche where ''C. glabrata'' must adhere to cause urinary tract infections. 
Consistent with the site of ''C. glabrata'' infection, Epa6 and Epa7 mediate binding to uroepithelial cells in vitro <ref name="Castano 2005"></ref><ref name="Domergue 2005">Domergue, R., Castano, I., de las Penas, A., Zupancic, M., Lockatell, V., Hebel, J.R. et al. 2005. Nicotinic acid limiation regulates silencing of Candida albicans adhesins during UTI. Science, 308, 866-870.</ref>. It has also been noted <ref name=" Zupancic, M.L., 2008"></ref> that "Epa1, Epa6, and Epa7 recognize the T antigen Gal-β1-3GalNAc-α-R, one of the major mucin-type O-glycans found in the colonic epithelium", another site colonized by ''C. glabrata''. 

=== Biosynthesis of ligands ===
On mucins, the T (Galβ1-3GalNAcα1-Thr/Ser) target ligand for EPA7 is generated by the action of a family of polypeptide O-GalNAc transferases followed by addition of galactose by galactosyltransferase. Transferases T1, T2, T3 and T4 have been suggested to be particularly important in mucin glycosylation.
 

=== Structure ===

Epa proteins are C-type lectins, but no detailed structural information for these proteins is yet available.

=== Biological roles of GBP-ligand interaction ===

Epa7 and other Epa family members, as summarized above, participate in adhesion of the pathogenic yeast ''Candida glabrata'' cells to host cells, leading to infection. Related proteins participate in cell:cell interactions between yeast that can be important for critical processes such as mating or biofilm formation.

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=EPA7&maxresults=20 CFG database search results for "EPA7"].

=== Glycan profiling ===

Glycan profiling of host cell glycans has not been used in connection with this paradigm.

=== Glycogene microarray ===
Mammalian glycogene profiling has not been performed for this paradigm of a fungal protein. Although yeast binding to mammalian cells could conceivably trigger changes in glycogene expression, the critical issue for this adhesin is which glycans are present on the mammalian cell surface upon initial contact. These structures will mediate the cell:cell interactions that are important for establishment of infection.

=== Knockout mouse lines ===

CFG knockout mouse lines have not been used for studies pertaining to this paradigm. Examining ''C. glabrata'' infection using wild type and ''epa'' mutant strains in mice with defects in terminal galactosylation could potentially be of interest.

=== Glycan array ===
The specificity of Epa7 and related proteins was determined through CFG glycan array analysis<ref name=" Zupancic, M.L., 2008"></ref> (click [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1056 here] to see results). To see glycan array results for other EPA family members, click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=EPA&cat=coreh here]. Flocculins from ''S. cerevisiae'' have also been examined by CFG glycan array analysis (click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=flocculin&cat=coreh here]), and glycan array studies of flocculins from ''P. Pastoris'' and of additional ''Candida'' Epa domains have been approved.

== Related GBPs ==
* 22 additional EPA family members in ''C. glabrata''
* Related proteins in ''S. cerevisiae''
* EPA7-like glycan-binding domain also occurs in predicted proteins of ''Ashbya gossypii'' and ''Kluyveromyces lactis''.
(Click here for [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=EPA&maxresults=20 CFG data] on EPA family members)

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Richard Cummings, Tamara Doering, Peter Lipke

Candida glabrata EPA7

2011-10-30T19:16:06Z

Kurt Drickamer:

'''Fungal adhesins with lectin properties''' 
Cell adhesion proteins on fungal cell surfaces mediate interactions both with other cells of the same type and with the external environment<ref>Douglas, L.M., Li, L., Yang, Y. and Dranginis, A.M. 2007. Expression and characterization of the flocculin Flo11/Muc1, a Saccharomyces cerevisiae mannoprotein with homotypic properties of adhesion. Eukaryot Cell, 6, 2214-2221.</ref><ref>Dranginis, A.M., Rauceo, J.M., Coronado, J.E. and Lipke, P.N. 2007. A biochemical guide to yeast adhesins: glycoproteins for social and antisocial occasions. Microbiol Mol Biol Rev, 71, 282-294.</ref>. These interactions impact critical processes including mating, pathogenesis, and biofilm formation. Fungal adhesins are typically GPI-anchored proteins that have been covalently linked to the cell wall, such that their N-terminal ligand binding domains extend from the cell surface. They frequently occur as families of related proteins<ref>Tronchin, G., Pihet, M., Lopes-Bezerra, L.M. and Bouchara, J.P. 2008. Adherence mechanisms in human pathogenic fungi. Med Mycol, 46, 749-772. </ref>. Members of two such groups, the flocculation/agglutination genes of the model yeast ''Saccharomyces cerevisiae''<ref>Kobayashi, O., Hayashi, N., Kuroki, R. and Sone, H. 1998. Region of FLO1 proteins responsible for sugar recognition. J Bacteriol, 180, 6503-6510.</ref> and the related EPA genes<ref>Kaur, R., Domergue, R., Zupancic, M.L. and Cormack, B.P. 2005. A yeast by any other name: Candida glabrata and its interaction with the host. Curr Opin Microbiol, 8, 378-384.</ref> of the pathogenic fungus ''Candida glabrata'', are lectins. Several of the 23 identified EPA genes have been functionally shown to mediate binding of ''C. glabrata'' to host cells<ref name="Castano 2005">Castano, I., Pan, S.J., Zupancic, M., Hennequin, C., Dujon, B. and Cormack, B.P. 2005. Telomere length control and transcriptional regulation of subtelomeric adhesins in Candida glabrata. Mol Microbiol, 55, 1246-1258.</ref><ref name="Domergue 2005">Domergue, R., Castano, I., de las Penas, A., Zupancic, M., Lockatell, V., Hebel, J.R. et al. 2005. Nicotinic acid limiation regulates silencing of Candida albicans adhesins during UTI. Science, 308, 866-870.</ref>, an essential step in infection and virulence. Defining the specificity of these proteins and their biological roles will elucidate the interactions between host and pathogen, and potentially indicate ways in which to inhibit them for the benefit of the host.

'''''Candida glabrata'' EPA7''' 
The EPA family was chosen as a paradigm because of its relevance to a fungal pathogen that affects human health that can be studied in mouse models of infection. EPA7 was chosen to represent this group because it has been demonstrated to function as an adhesin<ref name="Castano 2005"/> and is one of the EPA proteins that has been studied in the most detail. The N-terminal binding domain of this protein, expressed on the surface of S''. cerevisiae'', has been analyzed on the CFG glycan array. These studies demonstrated EPA7 binding specificity for β1,3- and β1,4-linked galactosides
<ref name=" Zupancic, M.L., 2008">
Zupancic, M.L., Frieman, M., Smith, D., Alvarez, R.A., Cummings, R.D. and Cormack, B.P. 2008. Glycan microarray analysis of Candida glabrata adhesin ligand specificity. Mol Microbiol, 68, 547-559.</ref><ref>de Groot, P.W.J. and Klis, F.M. 2008. The conserved PA14 domain of cell wall-associated fungal adhesins governs their glycan-binding specificity. Mol Microbiol, 68, 535-537. </ref>. This work represents a significant step forward in the area of lectin-like fungal adhesins; in general the specificity of these important proteins remains unexplored.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
* CFG Participating Investigators (PIs) who have contributed to studies of this paradigmatic protein include: Brendan Cormack, Rick Cummings
* PIs using CFG resources to study related ''S. cerevisiae'' proteins include: Lars-Oliver Essen (several flocculins), Peter Lipke (alpha agglutinin and ''Candida albicans'' Als adhesins)

== Progress toward understanding this GBP paradigm ==

=== Carbohydrate ligands ===

Carbohydrate ligands of Epa7 have been examined by glycan array analysis in work from the Cormack group <ref name=" Zupancic, M.L., 2008"></ref>and found to bind almost exclusively to non-reducing terminal β1-4 or β1-3-linked galactose residues. The Epa1 family member has similar specificity while Epa6 binds to most ligands with terminal galactose residues. The related ''S. cerevisiae'' flocculins bind α-mannose or α-glucose residues.

=== Cellular expression of GBP and ligands ===

EPA7 is expressed by the pathogenic fungus ''Candida glabrata''. The EPA gene family is subject to an interesting mechanism of regulation mediated by telomeric silencing. This silencing is relieved in low niacin, leading to increased protein expression. Because urine provides a low niacin growth environment, these adhesins are upregulated in precisely the niche where ''C. glabrata'' must adhere to cause urinary tract infections. 
Consistent with the site of ''C. glabrata'' infection, Epa6 and Epa7 mediate binding to uroepithelial cells in vitro <ref name="Castano 2005"></ref><ref name="Domergue 2005">Domergue, R., Castano, I., de las Penas, A., Zupancic, M., Lockatell, V., Hebel, J.R. et al. 2005. Nicotinic acid limiation regulates silencing of Candida albicans adhesins during UTI. Science, 308, 866-870.</ref>. It has also been noted <ref name=" Zupancic, M.L., 2008"></ref> that "Epa1, Epa6, and Epa7 recognize the T antigen Gal-β1-3GalNAc-α-R, one of the major mucin-type O-glycans found in the colonic epithelium", another site colonized by ''C. glabrata''. 

=== Biosynthesis of ligands ===
On mucins, the Tn (GalNAcα1-Thr/Ser) target ligand for EPA7 is generated by the action of a family of polypeptide O-GalNAc transferases. Transferases T1, T2, T3 and T4 have been suggested to be particularly important in mucin glycosylation.
 

=== Structure ===

Epa proteins are C-type lectins, but no detailed structural information for these proteins is yet available.

=== Biological roles of GBP-ligand interaction ===

Epa7 and other Epa family members, as summarized above, participate in adhesion of the pathogenic yeast ''Candida glabrata'' cells to host cells, leading to infection. Related proteins participate in cell:cell interactions between yeast that can be important for critical processes such as mating or biofilm formation.

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=EPA7&maxresults=20 CFG database search results for "EPA7"].

=== Glycan profiling ===

Glycan profiling of host cell glycans has not been used in connection with this paradigm.

=== Glycogene microarray ===
Mammalian glycogene profiling has not been performed for this paradigm of a fungal protein. Although yeast binding to mammalian cells could conceivably trigger changes in glycogene expression, the critical issue for this adhesin is which glycans are present on the mammalian cell surface upon initial contact. These structures will mediate the cell:cell interactions that are important for establishment of infection.

=== Knockout mouse lines ===

CFG knockout mouse lines have not been used for studies pertaining to this paradigm. Examining ''C. glabrata'' infection using wild type and ''epa'' mutant strains in mice with defects in terminal galactosylation could potentially be of interest.

=== Glycan array ===
The specificity of Epa7 and related proteins was determined through CFG glycan array analysis<ref name=" Zupancic, M.L., 2008"></ref> (click [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1056 here] to see results). To see glycan array results for other EPA family members, click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=EPA&cat=coreh here]. Flocculins from ''S. cerevisiae'' have also been examined by CFG glycan array analysis (click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=flocculin&cat=coreh here]), and glycan array studies of flocculins from ''P. Pastoris'' and of additional ''Candida'' Epa domains have been approved.

== Related GBPs ==
* 22 additional EPA family members in ''C. glabrata''
* Related proteins in ''S. cerevisiae''
* EPA7-like glycan-binding domain also occurs in predicted proteins of ''Ashbya gossypii'' and ''Kluyveromyces lactis''.
(Click here for [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=EPA&maxresults=20 CFG data] on EPA family members)

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Richard Cummings, Tamara Doering, Peter Lipke

CBM47

2011-10-29T12:07:20Z

Kurt Drickamer: /* Biosynthesis of ligands */

Enzymes that degrade host glycans are increasingly being found as virulence factors in pathogenic bacteria<ref>Shelburne, S. A., Davenport, M. T., Keith, D. B. & Musser, J. M. (2008). The role of complex carbohydrate catabolism in the pathogenesis of invasive streptococci. Trends Microbiol 16, 318-25.</ref><ref name="Hava 16">Hava, D. L. & Camilli, A. (2002). Large-scale identification of serotype 4 Streptococcus pneumoniae virulence factors. Mol Microbiol 45, 1389-406.</ref>. A common property of extracellular glycan degrading enzymes found in such bacteria is multi-modularity; these enzymes often comprise a large number of modules with a variety of functions. The most common class of ancillary module are carbohydrate-binding modules (CBMs)<ref>Boraston, A. B., Bolam, D. N., Gilbert, H. J. & Davies, G. J. (2004). Carbohydrate-binding modules: fine tuning polysaccharide recognition. Biochem J 382, 769-782.</ref>, which are alternatively referred to as lectin-domains. These modules are responsible for targeting carbohydrate-degrading enzymes to a glycan substrate or, when the enzymes are attached to the bacterial cell-surface, likely also function to adhere the bacterium to a glycan<ref>Ficko-Blean, E., Gregg, K. J., Adams, J. J., Hehemann, J. H., Czjzek, M., Smith, S. P. & Boraston, A. B. (2009). Portrait of an enzyme, a complete structural analysis of a multimodular {beta}-N-acetylglucosaminidase from Clostridium perfringens. J Biol Chem 284, 9876-84.</ref>. The presence of these lectin-domains in multi-modular proteins and their contribution of glycan binding function to catalytically active proteins distinguishes these modules from other bacterial glycan-binding proteins (GBPs). The CBM47 modules from the ''Streptococcus pneumoniae'' enzyme SpGH98 (or "fucolectin-related protein") are specific to the Lewisy antigen<ref name ="Boraston 2006">Boraston, A. B., Wang, D. & Burke, R. D. (2006). Blood group antigen recognition by a Streptococcus pneumoniae virulence factor. J Biol Chem 281, 35263-35271.</ref>, which is quite rare among all GBPs, and function to target this enzyme to this antigen when present on epithelial cells<ref name="Higgins 2009">Higgins, M. A., Whitworth, G. E., El Warry, N., Randriantsoa, M., Samain, E., Burke, R. D., Vocadlo, D. J. & Boraston, A. B. (2009). Differential recognition and hydrolysis of host carbohydrate antigens by Streptococcus pneumoniae family 98 glycoside hydrolases. J Biol Chem 284, 26161-73.</ref>. Recognition and destruction of this antigen appears to be a critical process in pneumococcal virulence<ref name="Hava 16"/><ref name="Embry 2007">Embry, A., Hinojosa, E. & Orihuela, C. J. (2007). Regions of Diversity 8, 9 and 13 contribute to Streptococcus pneumoniae virulence. BMC Microbiol 7, 80.</ref>.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
This is a very new area of investigation. CFG Participating Investigators (PIs) that have screened other CBMs or proteins containing CBMs include: Alisdair Boraston, Garry Taylor, Warren Wakarchuck

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about CBM47, its carbohydrate ligand(s), and how they interact to mediate cell communication.
=== Carbohydrate ligands ===
CBM47 is a fucose specific binding module that is related to ''Anguilla anguilla'' fucolectin. The high affinity ligand for CBM47 has been determined from glycan microarray screening on the CFG microarray[http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_GLYCAN_v3_34_08192004#]to be Fucα1-2Galβ1-4(Fucα1-3)GlcNAc [Lewis y]<ref name="Boraston 2006"/>.

[[File:Lewisy.jpg]]
 

=== Cellular expression of GBP and ligands ===
The CBM47 modules from the ''Streptococcus pneumoniae'' enzyme SpGH98 (or "fucolectin-related protein") are specific to the Lewisy antigen<ref name="Boraston 2006"/>, which is quite rare among all GBPs, and function to target this enzyme to this antigen when present on epithelial cells<ref name="Higgins 2009"/>.
 
=== Biosynthesis of ligands ===
Lewis Y synthesis requires the addition of both α1-2 fucose to the terminal galactose residue and α1-3 fucose to the sub-terminal GlcNAc residue on a type 2 chain. Addition of the α1-2 fucose can be catalyzed by fucosyltransferases FUT1 [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_598&sideMenu=true&pageType=general] and FUT2 [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_599&sideMenu=true&pageType=general], while addition of the α1-3 fucose can be catalyzed by FUT4 [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_601&sideMenu=true&pageType=general] and FUT9 [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_606&sideMenu=true&pageType=general]. In lung adenocarcinomas, the FUT1 and FUT4 enzymes are primarily responsible for Lewis Y synthesis.<ref>Yang, X, Zhang, Z, Jia, S, Liu, T Wang X, and Yan, Q (2007) Overexpression of fucosyltransferase IV in A431 cell line increases cell proliferation. Int. J. Biochem. Cell Biol. 39, 1722–1730</ref>
 

=== Structure ===

CBM47 originates from a multimodular ''S. pneumoniae'' that has an N-terminal, Lewisy degrading catalytic module. Indeed, three CBM47 modules are found in tandem.

[[File:modular.jpg]]

The high resolution X-ray structures of the N-terminal and C-terminal CBM47 modules have been determined and the N-terminal module in complex with the Lewisy tetrasaccharide<ref name="Boraston 2006"/>.

[[File:CBM47.jpg]]

 

=== Biological roles of GBP-ligand interaction ===

The primary role of CBM47, and indeed other CBMs found in carbohydrate-active enzymes, is to direct the entire enzyme to its glycan substrate. However, CBMs found in carbohydrate-active enzymes attached to microbial cell surfaces may also play a role in the adhesion of the bacterium to host glycan-bearing tissues.
 
Recognition and destruction of the Lewisy antigen by CBM47 appears to be a critical process in pneumococcal virulence<ref name="Hava 16"/><ref name="Embry 2007"/>.

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=CBM&maxresults=20 CFG database search results for CBM].

=== Glycan profiling ===

 
=== Glycogene microarray ===
CBM47 is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
Not applicable.
 

=== Glycan array ===
The specificity of several CBMs have been investigated by CFG glycan array analysis (click [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1831 here] for example). Isolated glycans for structural and quantitative binding studies have also been obtained from the CFG.

== Related GBPs ==

There are presently over 55 families of CBMs that are defined on the basis of amino acid sequence similarity; however, the majority of these CBMs families contain members specific for plant cell wall polysaccharides. CFG resources have been instrumental in studying the subset of CBMs that recognize complex glycans. In addition to CBM47 there are a number of CBMs belonging to family 32 and 51 that share the property of binding complex glycans. Though unrelated at the amino acid sequence level CBMs in families 32, 47, and 51 are structurally related and functionally related. It is important to note, however, that the diversity of complex glycan binding among these family members is considerable and only coming to light through glycan array screening. The availability of purfied glycans is facilitating structural and quantitative studies of glycan binding by CBMs in families 32, 47, and 51.

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Alisdair Boraston, Anne Imberty

C. difficile toxin A (TcdA)

2011-10-29T12:06:05Z

Kurt Drickamer: /* Biosynthesis of ligands */

'''The large clostridial cytotoxins (LCT)''' are a family of structurally and functionally related exotoxins from ''Clostridium difficile'' (toxins A and B [also termed TcdA and TcdB, respectively), ''C. sordellii'' (lethal and hemorrhagic toxin) and ''C. novyi'' (alpha-toxin). The LCTs are major virulence factors, which in addition to their in vivo effects, are cytotoxic to cultured cell lines, causing reorganization of the cytoskeleton accompanied by morphological changes<ref name="Just 1">Just. I., Gerhard, R. (2004). Large clostridial cytotoxins. Rev. Physiol. Biochem. Pharmacol. 152:23-47.</ref>. The LCTs are single-chain protein toxins, comprising three domains: receptor-binding, translocation and catalysis, which mediate cell entry via receptor-mediated endocytosis, translocation into the cytoplasm, and enzymatic cytotoxic activity, respectively. Enzymatic activity involves transfer of a glucosyl moiety from UDP-glucose (or the N-acetyl-glucosaminyl moiety from UDP-GlcNAc in the case of alpha toxin) to a conserved threonine within the effector regions of the intracellular Rho and Ras GTPases<ref name="Just 1"/>. The C-terminal receptor-binding domain comprises up to one third of the LCT molecule, and contains repetitive peptide elements called combined repetitive oligopetides (CROPs). The repeating units binding regions of certain streptococcal glycosyltransferases<ref name="Just 1"/>.

'''TcdA''' is the better characterized of the two LCTs produced by ''C. difficile.'' Collectively, TcdA and TcdB are directly responsible for the increasingly common and serious human gastrointestinal disease caused when antibiotic treatment enables ''C. difficile'' to out-compete commensal gut microflora. Recently, the crystal structure of a C-terminal fragment of TcdA has been solved, revealing a solenoid-like structure, which consists of 32 short repeats with 15–21 residues and seven long repeats with 30 residues<ref name="Jank 2007">Thomas Jank, Torsten Giesemann and Klaus Aktories. (2007). Rho-glucosylating Clostridium difficile toxins A and B: new insights into structure and function. Glycobiology. 17: 15R–22R.
</ref>. Solenoid structures are often found in bacterial surface proteins, and their extended surface allows protein–protein or protein–carbohydrate interactions. TcdA is known to bind to Galα1-3Galβ1-4GlcNAc- glycans, although this structure is not present in humans. However, it is also known to recognize a variety of other structures with a Galβ[1→4]GlcNAcβ- backbone, including the fucosylated blood group antigens Lewisx and Lewisy, both of which are present in human intestinal epithelium<ref name="Voth 2005">Voth, D. E., and Ballard, J. D. (2005). Clostridium difficile toxins: mechanism of action and role in disease. Clin. Microbiol. Rev. 18, 247-263.</ref>. Clearly, a better understanding of the identity/structure of the human receptor(s) for these toxins will facilitate design of novel therapeutics capable of blocking toxin binding. Glycan array analysis conducted by the CFG showed that TcdA bound most strongly to glycans terminating in Galβ1-3[Fucα1-4]GlcNAcβ1-3Galβ1-4-GlcNAc-, which mimics the blood group antigen Lewisa; other bound structures included Galα1-3[Fucα1-4]GlcNAcβ1-3Galβ1-4GlcNAcβ-, NeuAcα2-3Galβ1-3GlcNAcβ1-3Galβ1-4GlcNAcβ-, and Fucαa1-2[GalNAcαa1-3]Galβ1-4GlcNAcβ1-3Galβb1-4GlcNAcβ-.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
* CFG Participating Investigators (PIs) contributing to the understanding of TcdA include: Borden Lacy, Yashwant Mahida, Kenneth Ng
* Non-CFG PIs include: Brian Dieckgraefe

== Progress toward understanding this GBP paradigm ==

=== Carbohydrate ligands ===
*Galα1-3Galβ1-4GlcNAc- glycans (not present in humans). 
*Other structures with a Galβ[1→4]GlcNAcβ- backbone, including the fucosylated blood group antigens Lewisx and Lewisy, both of which are present in human intestinal epithelium<ref name="Voth 2005"/>. 
*Strongest binding: glycans terminating in Galβ1-3[Fucα1-4]GlcNAcβ1-3Galβ1-4-GlcNAc-, which mimics the blood group antigen Lewisa. 
*Also binds: Galα1-3[Fucα1-4]GlcNAcβ1-3Galβ1-4GlcNAcβ-, NeuAcα2-3Galβ1-3GlcNAcβ1-3Galβ1-4GlcNAcβ-, and Fucαa1-2[GalNAcαa1-3]Galβ1-4GlcNAcβ1-3Galβb1-4GlcNAcβ-. 
 
=== Cellular expression of GBP and ligands ===
TcdA is produced by ''Clostridium difficile''. Structurally and functionally related exotoxins in the LCT family are produced by ''C. sordellii'' (lethal and hemorrhagic toxin) and ''C. novyi'' (alpha-toxin).
 
TcdA binds the fucosylated blood group antigens Lewisx and Lewisy, which are present in human intestinal epithelium<ref name="Voth 2005"/> (see above).
=== Biosynthesis of ligands ===
The highest affinity ligand, Lewisa is created by the action of
[http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_600&sideMenu=true&pageType=general Fucosyltransferase 3]
acting on type 1 chains.
 
On type 2 chains, the biosynthesis of the alternative Lewisx and Lewisy ligands requires the action of [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_601&sideMenu=true&pageType=general Fucosyltransferase 4] and [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_606&sideMenu=true&pageType=general Fucosyltransferase 9] for addition of the α1-3 fucose and in the latter case action of
[http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_598&sideMenu=true&pageType=general Fucosyltransferase 1] and [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_599&sideMenu=true&pageType=general Fucosyltransferase 2]
for the addition of α1-2 fucose.
 

=== Structure ===
Members of the LCT family are single-chain protein toxins with receptor-binding, translocation and catalysis domains, which mediate cell entry via receptor-mediated endocytosis, translocation into the cytoplasm, and enzymatic cytotoxic activity, respectively. Up to one third of the LCT molecule is comprised of the C-terminal receptor-binding domain, which contains repetitive peptide elements called combined repetitive oligopeptides (CROPs).
 
X-ray crystallography has revealed the three-dimensional structures of several recombinant fragments of TcdA and related toxins<ref name="Jank 2007"/>. The N-terminal domain consists of a GT-A family glucosyltransferase that catalyzes the transfer of glucose from UDP-glucose to specific threonine residues of small GTPases regulating the structure and dynamics of the cytoskeleton. Although the three-dimensional structure of the GT domain of TcdA has not been solved by crystallography, the structures of closely related GT domains from TcdB and the letahal toxin from ''Clostridium sordellii'' have been determined.
 
The crystallographic structure of a cysteine protease domain bound to inositol hexakisphosphate has also been determined. This domain follows the N-terminal GT domain and is responsible for the autoproteolysis of TcdA that is important for releasing the GT domain into the cytoplasm.
 
Crystallographic structures of several recombinant fragments from the highly repetitive C-terminal domain have revealed an extended beta-solenoid structure that presents seven binding sites for complex oligosaccharide receptors. The bulk of this carbohydrate-binding domain is comprised of multiple copies of short repeats that interspersed with single copies of long repeats. Carbohydrate-binding sites appear to be formed at the junctions of long repeats and the preceding and following short repeats.
 
Crystallographic structures of recombinant fragments of TcdA have been determined with oligosaccharides, including the Gal-α(1,3)-LacNAc trisaccharide shown below<ref name = "Greco 2006">Greco, A et al. (2006). Carbohydrate recognition by ''Clostridium difficile'' toxin A. Nat. Struct. Mol. Biol. 13:460-461.</ref>. This trisaccharide was determined to be a likely native receptor for TcdA in the brush border membranes of intestinal epithelial cells from hamster<ref name = "Krivan 1986">Krivan, HC et al (1986). Cell-surface binding site for ''Clostridium difficile'' enterotoxin: evidence for a glycoconjugate containing the sequence Galα1,3-Galβ1,4-GlcNAc. Infect. Imm. 53:573-581.</ref>, an organism which is susceptible to ''C. difficile'' infection (CDI) and is often used as a model for studying the disease.
 
[[File:CD_fig1.png]]

=== Biological roles of GBP-ligand interaction ===
TcdA and TcdB, the other LCT produced by ''C. difficile'', cause the serious human gastrointestinal disease that results when antibiotic treatment enables ''C. difficile'' to out-compete commensal gut microflora. The LCTs are major virulence factors, which in addition to their in vivo effects, are cytotoxic to cultured cell lines, causing reorganization of the cytoskeleton accompanied by morphological changes<ref name="Just 1"/>.
 
== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=difficile&maxresults=20 CFG database search results for "difficile"].

=== Glycan profiling ===

 
=== Glycogene microarray ===
TcdA is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
Not applicable.
 

=== Glycan array ===
The CFG glycan array has been used to examine the [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_2693 glycan-binding specificity of TcdA]. In addition, the CFG's glycan synthesis capability is being used to prepare synthetic oligosaccharides indentified in the glycan array screens (with or without biotin tags) to further probe TcdA-receptor interactions.

== Related GBPs ==
''C. difficile'' toxin B (TcdB; [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=TcdB&maxresults=20 CFG data]), ''C. sordellii'' lethal toxin and hemorrhagic toxin, ''C. novyi'' alpha-toxin.

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Joseph Barbieri, Kenneth Ng, James Paton

F17G/GafD

2011-10-29T11:42:04Z

Kurt Drickamer: /* Cellular expression of GBP and ligands */

The F17-G (GafD) adhesin at the tip of flexible F17 fimbriae of enterotoxigenic ''Escherichia coli'' mediates binding to N-acetyl-β-D-glucosamine-presenting receptors on the microvilli of the intestinal epithelium of ruminants, leading to diarrhea or septicaemia. F17-G belong to two-domain adhesins (TDA)s consisting of a pilin domain and a lectin domain, both having an Ig-fold joined via a short interdomain linker
<ref name=" Buts, L2003">
Buts, L., Bouckaert, J., De Gents, E., Loris, R., Oscarson, S., Lahmann, M., Messens, J., Brosens, E., Wyns, L. & De Greve, H. (2003). The fimbrial adhesin F17-G of enterotoxigenic Escherichia coli has an immunoglobulin-like lectin domain that binds N-acetylglucosamine. Mol. Microb. 49, 705-715.</ref><ref>Merckel, M. C., Tanskanen, J., Edelman, S., Westerlund-Wilkström, B., Korhonen, T. K. & Goldman, A. (2003). The structural basis of receptor-binding by Escherichia coli associaed with diarrhea and septicemia. J. Mol. Biol. 331, 897-905.</ref>. Related adhesins have been characterized in enteropathogenic ''E. coli'' ( FedF on F18 fimbriae<ref>Coddens, A., Diswall, M., Angstrom, J., Breimer, M. E., Goddeeris, B., Cox, E. & Teneberg, S. (2009). Recognition of blood group ABH type 1 determinants by the FedF adhesin of F18-fimbriated Escherichia coli. J Biol Chem 284, 9713-26.</ref> and CfaE on CFA/I pili<ref>Poole, S. T., McVeigh, A. L., Anantha, R. P., Lee, L. H., Akay, Y. M., Pontzer, E. A., Scott, D. A., Bullitt, E. & Savarino, S. J. (2007). Donor strand complementation governs intersubunit interaction of fimbriae of the alternate chaperone pathway. Mol Microbiol 63, 1372-84.</ref>) ) and uropathogenic ones (FimH on type 1 fimbriae<ref>Bouckaert, J., Berglund, J., Schembri, M., De Gents, E., Cools, L., Wuhrer, M., Hung, C.-S., Pinkner, J., Slättegard, R., Savialov, A., Choudhury, D., Langermann, S., Hultgren, S. J., Wyns, L., Klemm, P., Oscarson, S., Knight, S. D. & De Greve, H. (2005). Receptor binding studies disclose a novel class of high-affinity inhibitors of the Escherichia coli FimH adhesin. Mol. Microb. 55, 441-455.</ref> and PapG on P-pili<ref>Dodson, K. W., Pinkner, J. S., Rose, T., Magnusson, G., Hultgren, S. J. & Waksman, G. (2001). Structural basis of the interaction of the pyelonephritic E. coli adhesin to ist human kideny receptor. Cell 105, 733-743.</ref>). Fimbrial adhesins from other organisms, such as CupB6 from ''Pseudomonas aeruginosa'' are also investigated. All share the immunoglobulin-like fold of the two structural components, despite lack of any sequence identity and diversity in carbohydrate specificity and binding site, and the corresponding pili are assembled by the chaperone-usher pathway<ref>De Greve, H., Wyns, L. & Bouckaert, J. (2007). Combining sites of bacterial fimbriae. Curr Opin Struct Biol 17, 506-12.</ref><ref>Sauer, F. G., Barnhart, M., Choudhury, D., Knight, S. D., Waksman, G. & Hultgren, S. J. (2000). Chaperone-assisted pilus assembly and bacterial attachment. Curr Opin Struct Biol 10, 548-56.</ref>. The paradigm is unique among TAD for his specificity toward GlcNAc. The binding site is located laterally and not at the tip of the pili, therefore the long and flexible F17 fimbriae could intrude between the microvilli of the epithelium, with the binding site of the lectin domain interacting laterally with GlcNAc-containing receptors. Five naturally occurring variants, differing in 1-18 amino acids of the adhesion domain have been identified<ref>De Kerpel, M., Van Molle, I., Brys, L., Wyns, L., De Greve, H. & Bouckaert, J. (2006). N-terminal truncation enables crystallization of the receptor-binding domain of the FedF bacterial adhesin. Acta Crystallogr Sect F Struct Biol Cryst Commun 62, 1278-82.</ref>.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
This is an emerging field of investigation and contributions arose from a small number of CFG Participating Investigators (PIs). These include: Esther Bullit, Eric Cox, Anne Imberty, Remy Loris, James Nataro

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about F17G/GafD, its carbohydrate ligand(s), and how they interact to mediate cell communication.
=== Carbohydrate ligands ===

The F17G adhesin is most specific for the disaccharide GlcNAcb1,3Gal that can be recognised as a terminal or internal sequence in bovine glycophorin <ref>Mouricout, M., Milhavet, M., Durié, C., Grange, P. Characterization of glycoprotein glycan receptors for Escherichia coli F17 fimbrial lectin, Microb. Pathog. (1995) 18, 297-306</ref>:
 
[[File:carbSynthe_0691_D000.jpg]]
 
The branched form gives a closely similar fluorescent signal:
 
[[File:carbSynthe_0897_D000.jpg]]
 
The presence of the b1,3 linkage of N-acetyl glucosamine to galactose enhances the affinity for F17G at least 2-fold, compared to the monosaccharide N-acetyl glucosamine, as validated using surface plasmon resonance measurements. Second best binders are the b1,4 and b1,6 galactose linked disaccharides, whereas chitobiose, that is also a characterized inhibitor of F17G-mediated bacterial adhesion, is clearly lagging behind. F17G can thus be ranked under glycan binding proteins that display high selectivity.

=== Cellular expression of GBP and ligands ===

F17G adhesins are expressed on enterotoxigenic E. coli infecting neonatal lambs, calves, and goat kids.
The F17G ligand GlcNAcb1,3Gal occurs universally but mostly internally in the sequence of poly-lactosaminyl glycans and blood group antigens.
These glycan structures are widely expressed on mamalian cell surfaces.
 
F17-fimbriated E. coli predominantly colonize neonatal animals, but also are a major causal agent (55%) of mastitis in bovines <ref>Lipman, L.J.A., de Nijs A., Gaastra W.. Isolation and identification of fimbriae and toxin production by Escherichia coli strains from cows with clinical mastitis, Vet. Microbiology 47 (1995) p. 1-7 </ref>. Congruent with the glycans recognized by F17G on the printed array versions 2.1 and 4.1, the N-acetyl glucosamine residue of GlcNAcb1,3Gal may be unsubstituted at the early life stage of calves, that are at the same time protected from bacterial infections by glycans secreted in the cow's milk.
 

=== Biosynthesis of ligands ===
The target sequence GlcNAcβ1-3Gal appears in O-linked glycans, where it is synthesized by [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_536&sideMenu=true&pageType=general UDP-GlcNAc:βGalβ1-3 GlcNAc transferase 3]. Other enzymes that can synthesize this linkage on N- and O-linked glycans include
[http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_537&sideMenu=true&pageType=general UDP-GlcNAc:βGal β1-3 GlcNAc transferase 4],
[http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_538&sideMenu=true&pageType=general UDP-GlcNAc:βGal β1-3 GlcNAc transferase 5],
[http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_547&sideMenu=true&pageType=general UDP-GlcNAc:βGal β1-3 GlcNAc transferase 6], and
[http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_562&sideMenu=true&pageType=general UDP-GlcNAc:βGal β1-3 GlcNAc transferase 7].
 

=== Structure ===
The F17G adhesin is a two-domain adhesin (TDA) located at the F17 fimbrial tip. The determination of the crystal structure of the F17G lectin domain led to the discovery of the variable immunoglobulin-like structure
as a paradigm for bacterial fimbrial TDAs <ref name=" Buts, L2003">
</ref>. F17G has a shallow groove for carbohydrate recognition on its flank.

 
[[File:F17G_Igfold_v3.jpg‎]]
 

=== Biological roles of GBP-ligand interaction ===

The F17G fimbrial lectin enhances intestinal colonization in the early life of ruminants. The long and flexible F17 fimbriae can penetrate deep between intestinal microvilli, where the fimbrial tip adhesin finds its glycan receptors. The subsequent secretion of heat stable and heat labile toxins can lead to severe diarrhea.

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the CFG database search results for [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=fimbriae&maxresults=20 fimbriae] and [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=pili&maxresults=20 pili].

=== Glycan profiling ===

 
=== Glycogene microarray ===
F17G/GafD is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
Not applicable.
 

=== Glycan array ===
F17G adhesins have been screened for their glycan specificity (click [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_PA_v2_177_11182005 here]). To see all glycan array results for F17G adhesin, click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=F17G&cat=coreh here].

== Related GBPs ==
FedF [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=FedF&maxresults=20 (CFG data)], CfaE [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=CfaE&maxresults=20 (CFG data)], FimH [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=FimH&maxresults=20 (CFG data)], PapG, CupB6 [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=CupB6&maxresults=20 (CFG data)].

The specificity of some of the other fimbrial tip adhesins was determined by CFG glycan array analysis ([http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_2358 ''P. gingivalis'' fimbriae], [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_PA_v2_178_11182005 ''E. coli'' FedF adhesin], [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1106 ''E. coli'' CfaE adhesin from CFA/I pili])

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Alisdair Boraston, Julie Bouckaert, Anne Imberty

F17G/GafD

2011-10-29T11:41:24Z

Kurt Drickamer: /* Biosynthesis of ligands */

The F17-G (GafD) adhesin at the tip of flexible F17 fimbriae of enterotoxigenic ''Escherichia coli'' mediates binding to N-acetyl-β-D-glucosamine-presenting receptors on the microvilli of the intestinal epithelium of ruminants, leading to diarrhea or septicaemia. F17-G belong to two-domain adhesins (TDA)s consisting of a pilin domain and a lectin domain, both having an Ig-fold joined via a short interdomain linker
<ref name=" Buts, L2003">
Buts, L., Bouckaert, J., De Gents, E., Loris, R., Oscarson, S., Lahmann, M., Messens, J., Brosens, E., Wyns, L. & De Greve, H. (2003). The fimbrial adhesin F17-G of enterotoxigenic Escherichia coli has an immunoglobulin-like lectin domain that binds N-acetylglucosamine. Mol. Microb. 49, 705-715.</ref><ref>Merckel, M. C., Tanskanen, J., Edelman, S., Westerlund-Wilkström, B., Korhonen, T. K. & Goldman, A. (2003). The structural basis of receptor-binding by Escherichia coli associaed with diarrhea and septicemia. J. Mol. Biol. 331, 897-905.</ref>. Related adhesins have been characterized in enteropathogenic ''E. coli'' ( FedF on F18 fimbriae<ref>Coddens, A., Diswall, M., Angstrom, J., Breimer, M. E., Goddeeris, B., Cox, E. & Teneberg, S. (2009). Recognition of blood group ABH type 1 determinants by the FedF adhesin of F18-fimbriated Escherichia coli. J Biol Chem 284, 9713-26.</ref> and CfaE on CFA/I pili<ref>Poole, S. T., McVeigh, A. L., Anantha, R. P., Lee, L. H., Akay, Y. M., Pontzer, E. A., Scott, D. A., Bullitt, E. & Savarino, S. J. (2007). Donor strand complementation governs intersubunit interaction of fimbriae of the alternate chaperone pathway. Mol Microbiol 63, 1372-84.</ref>) ) and uropathogenic ones (FimH on type 1 fimbriae<ref>Bouckaert, J., Berglund, J., Schembri, M., De Gents, E., Cools, L., Wuhrer, M., Hung, C.-S., Pinkner, J., Slättegard, R., Savialov, A., Choudhury, D., Langermann, S., Hultgren, S. J., Wyns, L., Klemm, P., Oscarson, S., Knight, S. D. & De Greve, H. (2005). Receptor binding studies disclose a novel class of high-affinity inhibitors of the Escherichia coli FimH adhesin. Mol. Microb. 55, 441-455.</ref> and PapG on P-pili<ref>Dodson, K. W., Pinkner, J. S., Rose, T., Magnusson, G., Hultgren, S. J. & Waksman, G. (2001). Structural basis of the interaction of the pyelonephritic E. coli adhesin to ist human kideny receptor. Cell 105, 733-743.</ref>). Fimbrial adhesins from other organisms, such as CupB6 from ''Pseudomonas aeruginosa'' are also investigated. All share the immunoglobulin-like fold of the two structural components, despite lack of any sequence identity and diversity in carbohydrate specificity and binding site, and the corresponding pili are assembled by the chaperone-usher pathway<ref>De Greve, H., Wyns, L. & Bouckaert, J. (2007). Combining sites of bacterial fimbriae. Curr Opin Struct Biol 17, 506-12.</ref><ref>Sauer, F. G., Barnhart, M., Choudhury, D., Knight, S. D., Waksman, G. & Hultgren, S. J. (2000). Chaperone-assisted pilus assembly and bacterial attachment. Curr Opin Struct Biol 10, 548-56.</ref>. The paradigm is unique among TAD for his specificity toward GlcNAc. The binding site is located laterally and not at the tip of the pili, therefore the long and flexible F17 fimbriae could intrude between the microvilli of the epithelium, with the binding site of the lectin domain interacting laterally with GlcNAc-containing receptors. Five naturally occurring variants, differing in 1-18 amino acids of the adhesion domain have been identified<ref>De Kerpel, M., Van Molle, I., Brys, L., Wyns, L., De Greve, H. & Bouckaert, J. (2006). N-terminal truncation enables crystallization of the receptor-binding domain of the FedF bacterial adhesin. Acta Crystallogr Sect F Struct Biol Cryst Commun 62, 1278-82.</ref>.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
This is an emerging field of investigation and contributions arose from a small number of CFG Participating Investigators (PIs). These include: Esther Bullit, Eric Cox, Anne Imberty, Remy Loris, James Nataro

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about F17G/GafD, its carbohydrate ligand(s), and how they interact to mediate cell communication.
=== Carbohydrate ligands ===

The F17G adhesin is most specific for the disaccharide GlcNAcb1,3Gal that can be recognised as a terminal or internal sequence in bovine glycophorin <ref>Mouricout, M., Milhavet, M., Durié, C., Grange, P. Characterization of glycoprotein glycan receptors for Escherichia coli F17 fimbrial lectin, Microb. Pathog. (1995) 18, 297-306</ref>:
 
[[File:carbSynthe_0691_D000.jpg]]
 
The branched form gives a closely similar fluorescent signal:
 
[[File:carbSynthe_0897_D000.jpg]]
 
The presence of the b1,3 linkage of N-acetyl glucosamine to galactose enhances the affinity for F17G at least 2-fold, compared to the monosaccharide N-acetyl glucosamine, as validated using surface plasmon resonance measurements. Second best binders are the b1,4 and b1,6 galactose linked disaccharides, whereas chitobiose, that is also a characterized inhibitor of F17G-mediated bacterial adhesion, is clearly lagging behind. F17G can thus be ranked under glycan binding proteins that display high selectivity.

=== Cellular expression of GBP and ligands ===

F17G adhesins are expressed on enterotoxigenic E. coli infecting neonatal lambs, calves, and goat kids.
The F17G ligand GlcNAcb1,3Gal occurs universally but mostly internally in the sequence of poly-lactosaminyl glycans and blood group antigens.
These glycan structures are widely expressed on mamalian cell surfaces .

=== Biosynthesis of ligands ===
The target sequence GlcNAcβ1-3Gal appears in O-linked glycans, where it is synthesized by [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_536&sideMenu=true&pageType=general UDP-GlcNAc:βGalβ1-3 GlcNAc transferase 3]. Other enzymes that can synthesize this linkage on N- and O-linked glycans include
[http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_537&sideMenu=true&pageType=general UDP-GlcNAc:βGal β1-3 GlcNAc transferase 4],
[http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_538&sideMenu=true&pageType=general UDP-GlcNAc:βGal β1-3 GlcNAc transferase 5],
[http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_547&sideMenu=true&pageType=general UDP-GlcNAc:βGal β1-3 GlcNAc transferase 6], and
[http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_562&sideMenu=true&pageType=general UDP-GlcNAc:βGal β1-3 GlcNAc transferase 7].
 

=== Structure ===
The F17G adhesin is a two-domain adhesin (TDA) located at the F17 fimbrial tip. The determination of the crystal structure of the F17G lectin domain led to the discovery of the variable immunoglobulin-like structure
as a paradigm for bacterial fimbrial TDAs <ref name=" Buts, L2003">
</ref>. F17G has a shallow groove for carbohydrate recognition on its flank.

 
[[File:F17G_Igfold_v3.jpg‎]]
 

=== Biological roles of GBP-ligand interaction ===

The F17G fimbrial lectin enhances intestinal colonization in the early life of ruminants. The long and flexible F17 fimbriae can penetrate deep between intestinal microvilli, where the fimbrial tip adhesin finds its glycan receptors. The subsequent secretion of heat stable and heat labile toxins can lead to severe diarrhea.

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the CFG database search results for [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=fimbriae&maxresults=20 fimbriae] and [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=pili&maxresults=20 pili].

=== Glycan profiling ===

 
=== Glycogene microarray ===
F17G/GafD is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
Not applicable.
 

=== Glycan array ===
F17G adhesins have been screened for their glycan specificity (click [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_PA_v2_177_11182005 here]). To see all glycan array results for F17G adhesin, click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=F17G&cat=coreh here].

== Related GBPs ==
FedF [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=FedF&maxresults=20 (CFG data)], CfaE [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=CfaE&maxresults=20 (CFG data)], FimH [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=FimH&maxresults=20 (CFG data)], PapG, CupB6 [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=CupB6&maxresults=20 (CFG data)].

The specificity of some of the other fimbrial tip adhesins was determined by CFG glycan array analysis ([http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_2358 ''P. gingivalis'' fimbriae], [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_PA_v2_178_11182005 ''E. coli'' FedF adhesin], [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1106 ''E. coli'' CfaE adhesin from CFA/I pili])

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Alisdair Boraston, Julie Bouckaert, Anne Imberty

F17G/GafD

2011-10-29T11:40:27Z

Kurt Drickamer: /* Biosynthesis of ligands */

The F17-G (GafD) adhesin at the tip of flexible F17 fimbriae of enterotoxigenic ''Escherichia coli'' mediates binding to N-acetyl-β-D-glucosamine-presenting receptors on the microvilli of the intestinal epithelium of ruminants, leading to diarrhea or septicaemia. F17-G belong to two-domain adhesins (TDA)s consisting of a pilin domain and a lectin domain, both having an Ig-fold joined via a short interdomain linker
<ref name=" Buts, L2003">
Buts, L., Bouckaert, J., De Gents, E., Loris, R., Oscarson, S., Lahmann, M., Messens, J., Brosens, E., Wyns, L. & De Greve, H. (2003). The fimbrial adhesin F17-G of enterotoxigenic Escherichia coli has an immunoglobulin-like lectin domain that binds N-acetylglucosamine. Mol. Microb. 49, 705-715.</ref><ref>Merckel, M. C., Tanskanen, J., Edelman, S., Westerlund-Wilkström, B., Korhonen, T. K. & Goldman, A. (2003). The structural basis of receptor-binding by Escherichia coli associaed with diarrhea and septicemia. J. Mol. Biol. 331, 897-905.</ref>. Related adhesins have been characterized in enteropathogenic ''E. coli'' ( FedF on F18 fimbriae<ref>Coddens, A., Diswall, M., Angstrom, J., Breimer, M. E., Goddeeris, B., Cox, E. & Teneberg, S. (2009). Recognition of blood group ABH type 1 determinants by the FedF adhesin of F18-fimbriated Escherichia coli. J Biol Chem 284, 9713-26.</ref> and CfaE on CFA/I pili<ref>Poole, S. T., McVeigh, A. L., Anantha, R. P., Lee, L. H., Akay, Y. M., Pontzer, E. A., Scott, D. A., Bullitt, E. & Savarino, S. J. (2007). Donor strand complementation governs intersubunit interaction of fimbriae of the alternate chaperone pathway. Mol Microbiol 63, 1372-84.</ref>) ) and uropathogenic ones (FimH on type 1 fimbriae<ref>Bouckaert, J., Berglund, J., Schembri, M., De Gents, E., Cools, L., Wuhrer, M., Hung, C.-S., Pinkner, J., Slättegard, R., Savialov, A., Choudhury, D., Langermann, S., Hultgren, S. J., Wyns, L., Klemm, P., Oscarson, S., Knight, S. D. & De Greve, H. (2005). Receptor binding studies disclose a novel class of high-affinity inhibitors of the Escherichia coli FimH adhesin. Mol. Microb. 55, 441-455.</ref> and PapG on P-pili<ref>Dodson, K. W., Pinkner, J. S., Rose, T., Magnusson, G., Hultgren, S. J. & Waksman, G. (2001). Structural basis of the interaction of the pyelonephritic E. coli adhesin to ist human kideny receptor. Cell 105, 733-743.</ref>). Fimbrial adhesins from other organisms, such as CupB6 from ''Pseudomonas aeruginosa'' are also investigated. All share the immunoglobulin-like fold of the two structural components, despite lack of any sequence identity and diversity in carbohydrate specificity and binding site, and the corresponding pili are assembled by the chaperone-usher pathway<ref>De Greve, H., Wyns, L. & Bouckaert, J. (2007). Combining sites of bacterial fimbriae. Curr Opin Struct Biol 17, 506-12.</ref><ref>Sauer, F. G., Barnhart, M., Choudhury, D., Knight, S. D., Waksman, G. & Hultgren, S. J. (2000). Chaperone-assisted pilus assembly and bacterial attachment. Curr Opin Struct Biol 10, 548-56.</ref>. The paradigm is unique among TAD for his specificity toward GlcNAc. The binding site is located laterally and not at the tip of the pili, therefore the long and flexible F17 fimbriae could intrude between the microvilli of the epithelium, with the binding site of the lectin domain interacting laterally with GlcNAc-containing receptors. Five naturally occurring variants, differing in 1-18 amino acids of the adhesion domain have been identified<ref>De Kerpel, M., Van Molle, I., Brys, L., Wyns, L., De Greve, H. & Bouckaert, J. (2006). N-terminal truncation enables crystallization of the receptor-binding domain of the FedF bacterial adhesin. Acta Crystallogr Sect F Struct Biol Cryst Commun 62, 1278-82.</ref>.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
This is an emerging field of investigation and contributions arose from a small number of CFG Participating Investigators (PIs). These include: Esther Bullit, Eric Cox, Anne Imberty, Remy Loris, James Nataro

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about F17G/GafD, its carbohydrate ligand(s), and how they interact to mediate cell communication.
=== Carbohydrate ligands ===

The F17G adhesin is most specific for the disaccharide GlcNAcb1,3Gal that can be recognised as a terminal or internal sequence in bovine glycophorin <ref>Mouricout, M., Milhavet, M., Durié, C., Grange, P. Characterization of glycoprotein glycan receptors for Escherichia coli F17 fimbrial lectin, Microb. Pathog. (1995) 18, 297-306</ref>:
 
[[File:carbSynthe_0691_D000.jpg]]
 
The branched form gives a closely similar fluorescent signal:
 
[[File:carbSynthe_0897_D000.jpg]]
 
The presence of the b1,3 linkage of N-acetyl glucosamine to galactose enhances the affinity for F17G at least 2-fold, compared to the monosaccharide N-acetyl glucosamine, as validated using surface plasmon resonance measurements. Second best binders are the b1,4 and b1,6 galactose linked disaccharides, whereas chitobiose, that is also a characterized inhibitor of F17G-mediated bacterial adhesion, is clearly lagging behind. F17G can thus be ranked under glycan binding proteins that display high selectivity.

=== Cellular expression of GBP and ligands ===

F17G adhesins are expressed on enterotoxigenic E. coli infecting neonatal lambs, calves, and goat kids.
The F17G ligand GlcNAcb1,3Gal occurs universally but mostly internally in the sequence of poly-lactosaminyl glycans and blood group antigens.
These glycan structures are widely expressed on mamalian cell surfaces .

=== Biosynthesis of ligands ===
The target sequence GlcNAcβ1-3Gal appears in O-linked glycans, where it is synthesized by [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_536&sideMenu=true&pageType=general UDP-GlcNAc:βGalβ1-3 GlcNAc transferase 3]. Other enzymes that can synthesize this linkage on N- and O-linked glycans include
[http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_537&sideMenu=true&pageType=general UDP-GlcNAc:βGal β1-3 GlcNAc transferase 4],
[http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_538&sideMenu=true&pageType=general UDP-GlcNAc:βGal β1-3 GlcNAc transferase 5],
[http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_547&sideMenu=true&pageType=general UDP-GlcNAc:βGal β1-3 GlcNAc transferase 6], and
[http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_562&sideMenu=true&pageType=general UDP-GlcNAc:βGal β1-3 GlcNAc transferase 7].
 
F17-fimbriated E. coli predominantly colonize neonatal animals, but also are a major causal agent (55%) of mastitis in bovines <ref>Lipman, L.J.A., de Nijs A., Gaastra W.. Isolation and identification of fimbriae and toxin production by Escherichia coli strains from cows with clinical mastitis, Vet. Microbiology 47 (1995) p. 1-7 </ref>. Congruent with the glycans recognized by F17G on the printed array versions 2.1 and 4.1, the N-acetyl glucosamine residue of GlcNAcb1,3Gal may be unsubstituted at the early life stage of calves, that are at the same time protected from bacterial infections by glycans secreted in the cow's milk.

=== Structure ===
The F17G adhesin is a two-domain adhesin (TDA) located at the F17 fimbrial tip. The determination of the crystal structure of the F17G lectin domain led to the discovery of the variable immunoglobulin-like structure
as a paradigm for bacterial fimbrial TDAs <ref name=" Buts, L2003">
</ref>. F17G has a shallow groove for carbohydrate recognition on its flank.

 
[[File:F17G_Igfold_v3.jpg‎]]
 

=== Biological roles of GBP-ligand interaction ===

The F17G fimbrial lectin enhances intestinal colonization in the early life of ruminants. The long and flexible F17 fimbriae can penetrate deep between intestinal microvilli, where the fimbrial tip adhesin finds its glycan receptors. The subsequent secretion of heat stable and heat labile toxins can lead to severe diarrhea.

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the CFG database search results for [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=fimbriae&maxresults=20 fimbriae] and [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=pili&maxresults=20 pili].

=== Glycan profiling ===

 
=== Glycogene microarray ===
F17G/GafD is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
Not applicable.
 

=== Glycan array ===
F17G adhesins have been screened for their glycan specificity (click [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_PA_v2_177_11182005 here]). To see all glycan array results for F17G adhesin, click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=F17G&cat=coreh here].

== Related GBPs ==
FedF [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=FedF&maxresults=20 (CFG data)], CfaE [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=CfaE&maxresults=20 (CFG data)], FimH [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=FimH&maxresults=20 (CFG data)], PapG, CupB6 [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=CupB6&maxresults=20 (CFG data)].

The specificity of some of the other fimbrial tip adhesins was determined by CFG glycan array analysis ([http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_2358 ''P. gingivalis'' fimbriae], [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_PA_v2_178_11182005 ''E. coli'' FedF adhesin], [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1106 ''E. coli'' CfaE adhesin from CFA/I pili])

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Alisdair Boraston, Julie Bouckaert, Anne Imberty

P-Selectin

2011-10-20T17:52:11Z

Kurt Drickamer: /* Biosynthesis of ligands */

The three selectins (P-selectin, L-selectin, and E-selectin) have related and sometimes overlapping functions in cell adhesion and mediate some of the best characterized glycan-dependent cell adhesion events. Of the ligands for these three C-type lectins, the target ligand of P-selectin, P-selectin glycoprotein ligand 1 (PSGL-1), is the best understood. Thus, P-selectin is used here to represent all three selectins.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
Selectin research was already at a relatively mature stage when the CFG began. Early PI work included structural studies, extensive analysis of leukocyte adhesion to endothelia ''in vivo'', and characterization of knockout mice to demonstrate physiological function. In addition to submitting samples for glycan array analysis, PIs have been involved in analyzing selectin expression under different conditions, including in knockout mice lacking enzymes for making target ligands.
* PIs working on P-selectin include: Hans-Peter Altevogt, Bruce Bochner, Pi-Wan Cheng, Richard Cummings, Robert Fuhlbrigge, Minoru Fukuda, Geoff Kansas, Klaus Ley, John Lowe, Rodger McEver, Steve Rosen, Ron Schnaar, Karen Snapp, Lloyd Stoolman, Martin Wild, Hermann Ziltener
* Non-PIs who have used CFG resources to study P-selectin include: Roland Contreras, Leonard Seymour

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about P-selectin, its carbohydrate ligands, and how they interact to mediate cell communication. Further information can be found in the GBP Molecule Pages for [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_hum_Ctlect_354&sideMenu=no human] and [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_mou_Ctlect_284&sideMenu=no mouse] P-selectin in the CFG database.
=== Carbohydrate ligands ===

P-selectin binds cooperatively to tyrosine sulfates, other amino acids, and a core 2 O-glycan capped with sialyl Lewis x, all positioned near the N terminus of PSGL-1<ref>Leppanen A, White SP, Helin J, McEver RP, Cummings RD (2000) Binding of glycosulfopeptides to P-selectin requires stereospecific contributions of individual tyrosine sulfate and sugar residues. J Biol Chem 275, 39569-39578.</ref>

=== Cellular expression of GBP and ligands ===

P-selectin is expressed on platelets, endothelial cells, and some macrophages
<ref name=" McEver RP 581">McEver RP (2002) Selectins: lectins that initiate cell adhesion under flow. Curr Opin Cell Biol 14, 581-588.</ref><ref>Tchernychev B, Furie B, Furie BC (2003) Peritoneal macrophages express both P-selectin and PSGL-1. J Cell Biol 163, 1145-1155</ref>. PSGL-1 is expressed on leukocytes and some endothelial cells<ref name=" McEver RP 581"></ref><ref>Rivera-Nieves J, Burcin TL, Olson TS, Morris MA, McDuffie M, Cominelli F, Ley K (2006) Critical role of endothelial P-selectin glycoprotein ligand 1 in chronic murine ileitis. J Clin Invest 203, 907-919</ref>.

=== Biosynthesis of ligands ===
SLeX (sialyl Lewis-X) like structures located on O-glycans at the N-terminus of PSGL-1 constitute the physiological ligands for all three members of the selectin family, L-, E- and P-selectin. Studies in which glycosyltransferases were reconstituted in heterologous cell types together with knockout mouse experiments suggest a role for [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_483&sideMenu=true&pageType=general polypeptide α-GalNAcT ppGalNAcT-1], [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_447&sideMenu=true&pageType=general core-1 β1,3GalactosylT T-synthase], [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_542&sideMenu=true&pageType=general core-2 β1,6GlcNAcT C2GnT-I], [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_436&sideMenu=true&pageType=general β1,4GalactosylT β4GalT-I], [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_625&sideMenu=true&pageType=general α(2,3)sialylT ST3GalT-IV] and α(1,3) fucosylTs (FTs), [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_601&sideMenu=true&pageType=general FTIV] and [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_604&sideMenu=true&pageType=general FTVII], in the synthesis of such structures. Sulfation of the peptide backbone by tyrosine sulfoT is also important for functional selectin ligand biosynthesis on PSGL-1.
 

=== Structure ===
[[image:P-selectin.jpg]] 
The structures of a fragment of P-selectin containing the CRD and EGF domains in complex with a sialyl Lewisx-containing oligosaccharide as well as a glycopeptide from PSGL-1 that contains sulfated tyrosine residues have been determined.<ref name="Somers2000">Somers W. S., Tang J., Shaw G. D,. Camphausen R. T. (2000) Insights into the molecular basis of leukocyte tethering and rolling revealed by structures of P- and E-selectin bound to SLex and PSGL-1. Cell 103, 467-479</ref> The fucose residue of the sialyl Lewisx tetrasaccharide fits in the primary binding site and interacts with a Ca2+ bound to the protein, with secondary contacts to the galactose residue and electrostatic interactions with the carboxyl group of sialic acid. The EGF domain is located on the opposite side of the CRD from the glycan-binding site.
 

=== Biological roles of GBP-ligand interaction ===

Interactions between P-selectin and PSGL-1 initiate rolling of leukocytes on activated platelets and endothelial cells as one of the earliest responses to tissue injury and infection<ref>McEver, R. P. (2001) Adhesive interactions of leukocytes, platelets, and the vessel wall during hemostasis and inflammation. Thromb Haemost 86, 746-756.</ref><ref name=" McEver RP 581"></ref><ref>McEver, R. P. and Zhu, C. (2010) Rolling cell adhesion. Annu Rev Cell Dev Biol 26, in press.</ref>. Engagement of PSGL-1 on neutrophils transduces signals that activate integrin LFA-1 to slow rolling on ICAM-1, thus augmenting neutrophil recruitment to inflammatory sites.<ref>Zarbock, A., Lowell, C. A., Ley, K. (2007) Spleen tyrosine kinase Syk is necessary for E-selectin-induced αLβ2 integrin-mediated rolling on intercellular adhesion molecule-1. Immunity 26, 773-783.</ref><ref>Zarbock, A., Abram, C. L., Hundt, M., Altman, A., Lowell, C. A., Ley, K. (2008) PSGL-1 engagement by E-selectin signals through Src kinase Fgr and ITAM adapters DAP12 and FcR gamma to induce slow leukocyte rolling. J Exp Med 205, 2339-2347.</ref><ref>Miner, J. J., Xia, L., Yago, T., Kappelmayer, J., Liu, Z., Klopocki, A. G., Shao, B., McDaniel, J. M., Setiadi, H., Schmidtke, D. W., McEver, R. P. (2008) Separable requirements for cytoplasmic domain of PSGL-1 in leukocyte rolling and signaling under flow. Blood 112, 2035-2045.</ref><ref>Yago, T., Shao, B., Miner, J. J., Yao, L., Klopocki, A. G., Maeda, K., Coggeshall, K. M., McEver, R. P. (2010) E-selectin engages PSGL-1 and CD44 through a common signaling pathway to induce integrin αLβ2-mediated slow leukocyte rolling. Blood March 18 [Epub ahead of print].</ref><ref>Mueller, H., Stadtmann, A., Van Aken, H., Hirsch, E., Wang, D., Ley, K., Zarbock, A. (2010) Tyrosine kinase Btk regulates E-selectin-mediated integrin activation and neutrophil recruitment by controlling phospholipase C (PLC) gamma2 and PI3Kgamma pathways. Blood 115, 3118-27.</ref>
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=P-selectin&maxresults=20 CFG database search results for P-selectin].

=== Glycan profiling ===
The glycans on the main target for P-selectin, P-selectin glycoprotein ligand 1 (PSGL-1), were analyzed.<ref name="Kawar2008">Kawar ZS, Johnson TK, Natunen S, Lowe JB, Cummings RD (2008) PSGL-1 from the murine leukocytic cell line WEHI-3 is enriched for core 2-based O-glycans with sialyl Lewis x antigen. Glycobiology 18, 441-446</ref>

=== Glycogene microarray ===
Probes for all three human and mouse selectins have been included in all versions of the CFG glycogene chip. Regulation of P-selectin expression was analyzed under multiple conditions; see all results [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=p-selectin&cat=coree here].

=== Knockout mouse lines ===
The [https://www.functionalglycomics.org/glycomics/publicdata/phenotyping.jsp phenotype] of PSGL-1 knockout mice was analyzed by the CFG. The CFG did not generate mice deficient in the P-selectin gene, as these mice were published in 1993<ref name="Mayadas 1993">Mayadas TN, Johnson RC, Rayburn H, Hynes RO, Wagner DD. Leukocyte rolling and extravasation are severely compromised in P selectin-deficient mice. Cell. 1993 Aug 13;74(3):541-54. PubMed PMID: 7688665.</ref> and have since been extensively studied. P-selectin knockout mice exhibit defects in leukocyte behavior, including elevated numbers of circulating neutrophils, loss of leukocyte rolling in mesenteric venules, and delayed neutrophil recruitment to the peritoneal cavity after induction of inflammation<ref name="Mayadas 1993"/>. They also show attentuated polymorphonuclear leukocyte accumulation and myocardial injury following brief ischaemia-reperfusion of the myocardium (i.e., P-selectin deficiency is cardioprotective; reviewed in <ref>Kakkar AK, Lefer DJ. Leukocyte and endothelial adhesion molecule studies in knockout mice. Curr Opin Pharmacol. 2004 Apr;4(2):154-8. Review. PubMed PMID:15063359.</ref>.)

=== Glycan array ===
The comparative binding specificities of [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1659 human] and [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1095 mouse] P-selectins have been analyzed. See all glycan array results for P-selectin [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=P-selectin&cat=coreh here].

== Related GBPs ==
L-selectin [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=L-selectin&maxresults=20 (CFG data)]and E-selectin [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=E-selectin&maxresults=20 (CFG data)].

== References ==
<references/>
* Mitoma J, Miyazaki T, Sutton-Smith M, Suzuki M, Saito H, Yeh JC, Kawano T, Hindsgaul O, Seeberger PH, Panico M, Haslam SM, Morris HR, Cummings RD, Dell A, Fukuda M (2009) The N-glycolyl form of mouse sialyl Lewis X is recognized by selectins but not by HECA-452 and FH6 antibodies that were raised against human cells. Glycoconj J 26, 511-523.
* Kawar ZS, Johnson TK, Natunen S, Lowe JB, Cummings RD (2008) PSGL-1 from the murine leukocytic cell line WEHI-3 is enriched for core 2-based O-glycans with sialyl Lewis x antigen. Glycobiology 18, 441-446.
* Mitoma J, Bao X, Petryanik B, Schaerli P, Gauguet JM, Yu SY, Kawashima H, Saito H, Ohtsubo K, Marth JD, Khoo KH, von Andrian UH, Lowe JB, Fukuda M (2007) Critical functions of N-glycans in L-selectin-mediated lymphocyte homing and recruitment. Nat Immunol 8, 409-418.
* Veerman KM, Williams MJ, Uchimura K, Singer MS, Merzaban JS, Naus S, Carlow DA, Owen P, Rivera-Nieves J, Rosen SD, Ziltener HJ (2007) Interaction of the selectin ligand PSGL-1 with chemokines CCL21 and CCL19 facilitates efficient homing of T cells to secondary lymphoid organs. Nat Immunol 8, 532-539.
* Chen S, Kawashima H, Lowe JB, Lanier LL, Fukuda M (2005) Suppression of tumor formation in lymph nodes by L-selectin-mediated natural killer cell recruitment. J Exp Med 202, 1679-1689.
* Kawashima H, Petryniak B, Hiraoka N, Mitoma J, Huckaby V, Nakayama J, Uchimura K, Kadomatsu K, Muramatsu T, Lowe JB, Fukuda M (2005) N-acetylglucosamine-6-O-sulfotransferases 1 and 2 cooperatively control lymphocyte homing through L-selectin ligand biosynthesis in high endothelial venules. Nat Immunol 6, 1096-1104.
* Piccio L, Rossi B, Colantonio L, Grenningloh R, Gho A, Ottoboni L, Homeister JW, Scarpini E, Martinello M, Laudanna C, DAmbrosio D, Lowe JB, (2005) Constantin G Efficient recruitment of lymphocytes in inflamed brain venules requires expression of cutaneous lymphocyte antigen and fucosyltransferase-VII. J Immunol 174, 5805-5813.
* Homeister JW, Daugherty A, Lowe JB (2004) α(1,3)Fucosyltransferases FucT-IV and FucT-VII control susceptibility to atherosclerosis in apolipoprotein E -/- mice. Arterioscler Thromb Vasc Biol 24, 1897-1903.
* Lowe JB (2003) Glycan-dependent leukocyte adhesion and recruitment in inflammation Curr Opin Cell Biol 15, 531-538.
* Smith PL, Myers JT, Rogers CE, Zhou L, Petryniak B, Becher DJ, Homeister JW, Lowe JB (2002) Conditional control of selectin ligand expression and global fucosylation events in mice with a targeted mutation at the FX locus. J Cell Biol 158, 801-815.

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Kurt Drickamer, Rodger McEver, Yvette van Kooyk

P-Selectin

2011-10-20T14:11:49Z

Kurt Drickamer: /* Progress toward understanding this GBP paradigm */

The three selectins (P-selectin, L-selectin, and E-selectin) have related and sometimes overlapping functions in cell adhesion and mediate some of the best characterized glycan-dependent cell adhesion events. Of the ligands for these three C-type lectins, the target ligand of P-selectin, P-selectin glycoprotein ligand 1 (PSGL-1), is the best understood. Thus, P-selectin is used here to represent all three selectins.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
Selectin research was already at a relatively mature stage when the CFG began. Early PI work included structural studies, extensive analysis of leukocyte adhesion to endothelia ''in vivo'', and characterization of knockout mice to demonstrate physiological function. In addition to submitting samples for glycan array analysis, PIs have been involved in analyzing selectin expression under different conditions, including in knockout mice lacking enzymes for making target ligands.
* PIs working on P-selectin include: Hans-Peter Altevogt, Bruce Bochner, Pi-Wan Cheng, Richard Cummings, Robert Fuhlbrigge, Minoru Fukuda, Geoff Kansas, Klaus Ley, John Lowe, Rodger McEver, Steve Rosen, Ron Schnaar, Karen Snapp, Lloyd Stoolman, Martin Wild, Hermann Ziltener
* Non-PIs who have used CFG resources to study P-selectin include: Roland Contreras, Leonard Seymour

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about P-selectin, its carbohydrate ligands, and how they interact to mediate cell communication. Further information can be found in the GBP Molecule Pages for [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_hum_Ctlect_354&sideMenu=no human] and [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_mou_Ctlect_284&sideMenu=no mouse] P-selectin in the CFG database.
=== Carbohydrate ligands ===

P-selectin binds cooperatively to tyrosine sulfates, other amino acids, and a core 2 O-glycan capped with sialyl Lewis x, all positioned near the N terminus of PSGL-1<ref>Leppanen A, White SP, Helin J, McEver RP, Cummings RD (2000) Binding of glycosulfopeptides to P-selectin requires stereospecific contributions of individual tyrosine sulfate and sugar residues. J Biol Chem 275, 39569-39578.</ref>

=== Cellular expression of GBP and ligands ===

P-selectin is expressed on platelets, endothelial cells, and some macrophages
<ref name=" McEver RP 581">McEver RP (2002) Selectins: lectins that initiate cell adhesion under flow. Curr Opin Cell Biol 14, 581-588.</ref><ref>Tchernychev B, Furie B, Furie BC (2003) Peritoneal macrophages express both P-selectin and PSGL-1. J Cell Biol 163, 1145-1155</ref>. PSGL-1 is expressed on leukocytes and some endothelial cells<ref name=" McEver RP 581"></ref><ref>Rivera-Nieves J, Burcin TL, Olson TS, Morris MA, McDuffie M, Cominelli F, Ley K (2006) Critical role of endothelial P-selectin glycoprotein ligand 1 in chronic murine ileitis. J Clin Invest 203, 907-919</ref>.

=== Biosynthesis of ligands ===
SLeX (sialyl Lewis-X) like structures located on O-glycans at the N-terminus of PSGL-1 constitute the physiological ligands for all three members of the selectin family, L-, E- and P-selectin. Studies in which glycosyltransferases were reconstituted in heterologous cell types together with knockout mouse experiments suggest a role for [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_483&sideMenu=true&pageType=general polypeptide α-GalNAcT ppGalNAcT-1], core-1 β1,3GalactosylT T-synthase [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_447&sideMenu=true&pageType=general], core-2 β1,6GlcNAcT C2GnT-I [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_542&sideMenu=true&pageType=general], β1,4GalactosylT β4GalT-I [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_436&sideMenu=true&pageType=general], α(2,3)sialylT ST3GalT-IV [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_625&sideMenu=true&pageType=general] and α(1,3) fucosylTs (FTs), FTIV [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_601&sideMenu=true&pageType=general] and FTVII [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_604&sideMenu=true&pageType=general], in the synthesis of such structures. Sulfation of the peptide backbone by tyrosine sulfoT is also important for functional selectin ligand biosynthesis on PSGL-1. 

=== Structure ===
[[image:P-selectin.jpg]] 
The structures of a fragment of P-selectin containing the CRD and EGF domains in complex with a sialyl Lewisx-containing oligosaccharide as well as a glycopeptide from PSGL-1 that contains sulfated tyrosine residues have been determined.<ref name="Somers2000">Somers W. S., Tang J., Shaw G. D,. Camphausen R. T. (2000) Insights into the molecular basis of leukocyte tethering and rolling revealed by structures of P- and E-selectin bound to SLex and PSGL-1. Cell 103, 467-479</ref> The fucose residue of the sialyl Lewisx tetrasaccharide fits in the primary binding site and interacts with a Ca2+ bound to the protein, with secondary contacts to the galactose residue and electrostatic interactions with the carboxyl group of sialic acid. The EGF domain is located on the opposite side of the CRD from the glycan-binding site.
 

=== Biological roles of GBP-ligand interaction ===

Interactions between P-selectin and PSGL-1 initiate rolling of leukocytes on activated platelets and endothelial cells as one of the earliest responses to tissue injury and infection<ref>McEver, R. P. (2001) Adhesive interactions of leukocytes, platelets, and the vessel wall during hemostasis and inflammation. Thromb Haemost 86, 746-756.</ref><ref name=" McEver RP 581"></ref><ref>McEver, R. P. and Zhu, C. (2010) Rolling cell adhesion. Annu Rev Cell Dev Biol 26, in press.</ref>. Engagement of PSGL-1 on neutrophils transduces signals that activate integrin LFA-1 to slow rolling on ICAM-1, thus augmenting neutrophil recruitment to inflammatory sites.<ref>Zarbock, A., Lowell, C. A., Ley, K. (2007) Spleen tyrosine kinase Syk is necessary for E-selectin-induced αLβ2 integrin-mediated rolling on intercellular adhesion molecule-1. Immunity 26, 773-783.</ref><ref>Zarbock, A., Abram, C. L., Hundt, M., Altman, A., Lowell, C. A., Ley, K. (2008) PSGL-1 engagement by E-selectin signals through Src kinase Fgr and ITAM adapters DAP12 and FcR gamma to induce slow leukocyte rolling. J Exp Med 205, 2339-2347.</ref><ref>Miner, J. J., Xia, L., Yago, T., Kappelmayer, J., Liu, Z., Klopocki, A. G., Shao, B., McDaniel, J. M., Setiadi, H., Schmidtke, D. W., McEver, R. P. (2008) Separable requirements for cytoplasmic domain of PSGL-1 in leukocyte rolling and signaling under flow. Blood 112, 2035-2045.</ref><ref>Yago, T., Shao, B., Miner, J. J., Yao, L., Klopocki, A. G., Maeda, K., Coggeshall, K. M., McEver, R. P. (2010) E-selectin engages PSGL-1 and CD44 through a common signaling pathway to induce integrin αLβ2-mediated slow leukocyte rolling. Blood March 18 [Epub ahead of print].</ref><ref>Mueller, H., Stadtmann, A., Van Aken, H., Hirsch, E., Wang, D., Ley, K., Zarbock, A. (2010) Tyrosine kinase Btk regulates E-selectin-mediated integrin activation and neutrophil recruitment by controlling phospholipase C (PLC) gamma2 and PI3Kgamma pathways. Blood 115, 3118-27.</ref>
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=P-selectin&maxresults=20 CFG database search results for P-selectin].

=== Glycan profiling ===
The glycans on the main target for P-selectin, P-selectin glycoprotein ligand 1 (PSGL-1), were analyzed.<ref name="Kawar2008">Kawar ZS, Johnson TK, Natunen S, Lowe JB, Cummings RD (2008) PSGL-1 from the murine leukocytic cell line WEHI-3 is enriched for core 2-based O-glycans with sialyl Lewis x antigen. Glycobiology 18, 441-446</ref>

=== Glycogene microarray ===
Probes for all three human and mouse selectins have been included in all versions of the CFG glycogene chip. Regulation of P-selectin expression was analyzed under multiple conditions; see all results [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=p-selectin&cat=coree here].

=== Knockout mouse lines ===
The [https://www.functionalglycomics.org/glycomics/publicdata/phenotyping.jsp phenotype] of PSGL-1 knockout mice was analyzed by the CFG. The CFG did not generate mice deficient in the P-selectin gene, as these mice were published in 1993<ref name="Mayadas 1993">Mayadas TN, Johnson RC, Rayburn H, Hynes RO, Wagner DD. Leukocyte rolling and extravasation are severely compromised in P selectin-deficient mice. Cell. 1993 Aug 13;74(3):541-54. PubMed PMID: 7688665.</ref> and have since been extensively studied. P-selectin knockout mice exhibit defects in leukocyte behavior, including elevated numbers of circulating neutrophils, loss of leukocyte rolling in mesenteric venules, and delayed neutrophil recruitment to the peritoneal cavity after induction of inflammation<ref name="Mayadas 1993"/>. They also show attentuated polymorphonuclear leukocyte accumulation and myocardial injury following brief ischaemia-reperfusion of the myocardium (i.e., P-selectin deficiency is cardioprotective; reviewed in <ref>Kakkar AK, Lefer DJ. Leukocyte and endothelial adhesion molecule studies in knockout mice. Curr Opin Pharmacol. 2004 Apr;4(2):154-8. Review. PubMed PMID:15063359.</ref>.)

=== Glycan array ===
The comparative binding specificities of [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1659 human] and [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1095 mouse] P-selectins have been analyzed. See all glycan array results for P-selectin [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=P-selectin&cat=coreh here].

== Related GBPs ==
L-selectin [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=L-selectin&maxresults=20 (CFG data)]and E-selectin [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=E-selectin&maxresults=20 (CFG data)].

== References ==
<references/>
* Mitoma J, Miyazaki T, Sutton-Smith M, Suzuki M, Saito H, Yeh JC, Kawano T, Hindsgaul O, Seeberger PH, Panico M, Haslam SM, Morris HR, Cummings RD, Dell A, Fukuda M (2009) The N-glycolyl form of mouse sialyl Lewis X is recognized by selectins but not by HECA-452 and FH6 antibodies that were raised against human cells. Glycoconj J 26, 511-523.
* Kawar ZS, Johnson TK, Natunen S, Lowe JB, Cummings RD (2008) PSGL-1 from the murine leukocytic cell line WEHI-3 is enriched for core 2-based O-glycans with sialyl Lewis x antigen. Glycobiology 18, 441-446.
* Mitoma J, Bao X, Petryanik B, Schaerli P, Gauguet JM, Yu SY, Kawashima H, Saito H, Ohtsubo K, Marth JD, Khoo KH, von Andrian UH, Lowe JB, Fukuda M (2007) Critical functions of N-glycans in L-selectin-mediated lymphocyte homing and recruitment. Nat Immunol 8, 409-418.
* Veerman KM, Williams MJ, Uchimura K, Singer MS, Merzaban JS, Naus S, Carlow DA, Owen P, Rivera-Nieves J, Rosen SD, Ziltener HJ (2007) Interaction of the selectin ligand PSGL-1 with chemokines CCL21 and CCL19 facilitates efficient homing of T cells to secondary lymphoid organs. Nat Immunol 8, 532-539.
* Chen S, Kawashima H, Lowe JB, Lanier LL, Fukuda M (2005) Suppression of tumor formation in lymph nodes by L-selectin-mediated natural killer cell recruitment. J Exp Med 202, 1679-1689.
* Kawashima H, Petryniak B, Hiraoka N, Mitoma J, Huckaby V, Nakayama J, Uchimura K, Kadomatsu K, Muramatsu T, Lowe JB, Fukuda M (2005) N-acetylglucosamine-6-O-sulfotransferases 1 and 2 cooperatively control lymphocyte homing through L-selectin ligand biosynthesis in high endothelial venules. Nat Immunol 6, 1096-1104.
* Piccio L, Rossi B, Colantonio L, Grenningloh R, Gho A, Ottoboni L, Homeister JW, Scarpini E, Martinello M, Laudanna C, DAmbrosio D, Lowe JB, (2005) Constantin G Efficient recruitment of lymphocytes in inflamed brain venules requires expression of cutaneous lymphocyte antigen and fucosyltransferase-VII. J Immunol 174, 5805-5813.
* Homeister JW, Daugherty A, Lowe JB (2004) α(1,3)Fucosyltransferases FucT-IV and FucT-VII control susceptibility to atherosclerosis in apolipoprotein E -/- mice. Arterioscler Thromb Vasc Biol 24, 1897-1903.
* Lowe JB (2003) Glycan-dependent leukocyte adhesion and recruitment in inflammation Curr Opin Cell Biol 15, 531-538.
* Smith PL, Myers JT, Rogers CE, Zhou L, Petryniak B, Becher DJ, Homeister JW, Lowe JB (2002) Conditional control of selectin ligand expression and global fucosylation events in mice with a targeted mutation at the FX locus. J Cell Biol 158, 801-815.

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Kurt Drickamer, Rodger McEver, Yvette van Kooyk

P-Selectin

2011-10-20T14:10:36Z

Kurt Drickamer: /* Biosynthesis of ligands */

The three selectins (P-selectin, L-selectin, and E-selectin) have related and sometimes overlapping functions in cell adhesion and mediate some of the best characterized glycan-dependent cell adhesion events. Of the ligands for these three C-type lectins, the target ligand of P-selectin, P-selectin glycoprotein ligand 1 (PSGL-1), is the best understood. Thus, P-selectin is used here to represent all three selectins.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
Selectin research was already at a relatively mature stage when the CFG began. Early PI work included structural studies, extensive analysis of leukocyte adhesion to endothelia ''in vivo'', and characterization of knockout mice to demonstrate physiological function. In addition to submitting samples for glycan array analysis, PIs have been involved in analyzing selectin expression under different conditions, including in knockout mice lacking enzymes for making target ligands.
* PIs working on P-selectin include: Hans-Peter Altevogt, Bruce Bochner, Pi-Wan Cheng, Richard Cummings, Robert Fuhlbrigge, Minoru Fukuda, Geoff Kansas, Klaus Ley, John Lowe, Rodger McEver, Steve Rosen, Ron Schnaar, Karen Snapp, Lloyd Stoolman, Martin Wild, Hermann Ziltener
* Non-PIs who have used CFG resources to study P-selectin include: Roland Contreras, Leonard Seymour

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about P-selectin, its carbohydrate ligands, and how they interact to mediate cell communication. Further information can be found in the GBP Molecule Pages for [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_hum_Ctlect_354&sideMenu=no human] and [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_mou_Ctlect_284&sideMenu=no mouse] P-selectin in the CFG database.
=== Carbohydrate ligands ===

P-selectin binds cooperatively to tyrosine sulfates, other amino acids, and a core 2 O-glycan capped with sialyl Lewis x, all positioned near the N terminus of PSGL-1<ref>Leppanen A, White SP, Helin J, McEver RP, Cummings RD (2000) Binding of glycosulfopeptides to P-selectin requires stereospecific contributions of individual tyrosine sulfate and sugar residues. J Biol Chem 275, 39569-39578.</ref>

=== Cellular expression of GBP and ligands ===

P-selectin is expressed on platelets, endothelial cells, and some macrophages
<ref name=" McEver RP 581">McEver RP (2002) Selectins: lectins that initiate cell adhesion under flow. Curr Opin Cell Biol 14, 581-588.</ref><ref>Tchernychev B, Furie B, Furie BC (2003) Peritoneal macrophages express both P-selectin and PSGL-1. J Cell Biol 163, 1145-1155</ref>. PSGL-1 is expressed on leukocytes and some endothelial cells<ref name=" McEver RP 581"></ref><ref>Rivera-Nieves J, Burcin TL, Olson TS, Morris MA, McDuffie M, Cominelli F, Ley K (2006) Critical role of endothelial P-selectin glycoprotein ligand 1 in chronic murine ileitis. J Clin Invest 203, 907-919</ref>.

=== Biosynthesis of ligands ===
SLeX (sialyl Lewis-X) like structures located on O-glycans at the N-terminus of PSGL-1 constitute the physiological ligands for all three members of the selectin family, L-, E- and P-selectin. Studies in which glycosyltransferases were reconstituted in heterologous cell types together with knockout mouse experiments suggest a role for polypeptide α-GalNAcT ppGalNAcT-1 [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_483&sideMenu=true&pageType=general], core-1 β1,3GalactosylT T-synthase [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_447&sideMenu=true&pageType=general], core-2 β1,6GlcNAcT C2GnT-I [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_542&sideMenu=true&pageType=general], β1,4GalactosylT β4GalT-I [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_436&sideMenu=true&pageType=general], α(2,3)sialylT ST3GalT-IV [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_625&sideMenu=true&pageType=general] and α(1,3) fucosylTs (FTs), FTIV [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_601&sideMenu=true&pageType=general] and FTVII [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_604&sideMenu=true&pageType=general], in the synthesis of such structures. Sulfation of the peptide backbone by tyrosine sulfoT is also important for functional selectin ligand biosynthesis on PSGL-1. 

=== Structure ===
[[image:P-selectin.jpg]] 
The structures of a fragment of P-selectin containing the CRD and EGF domains in complex with a sialyl Lewisx-containing oligosaccharide as well as a glycopeptide from PSGL-1 that contains sulfated tyrosine residues have been determined.<ref name="Somers2000">Somers W. S., Tang J., Shaw G. D,. Camphausen R. T. (2000) Insights into the molecular basis of leukocyte tethering and rolling revealed by structures of P- and E-selectin bound to SLex and PSGL-1. Cell 103, 467-479</ref> The fucose residue of the sialyl Lewisx tetrasaccharide fits in the primary binding site and interacts with a Ca2+ bound to the protein, with secondary contacts to the galactose residue and electrostatic interactions with the carboxyl group of sialic acid. The EGF domain is located on the opposite side of the CRD from the glycan-binding site.
 

=== Biological roles of GBP-ligand interaction ===

Interactions between P-selectin and PSGL-1 initiate rolling of leukocytes on activated platelets and endothelial cells as one of the earliest responses to tissue injury and infection<ref>McEver, R. P. (2001) Adhesive interactions of leukocytes, platelets, and the vessel wall during hemostasis and inflammation. Thromb Haemost 86, 746-756.</ref><ref name=" McEver RP 581"></ref><ref>McEver, R. P. and Zhu, C. (2010) Rolling cell adhesion. Annu Rev Cell Dev Biol 26, in press.</ref>. Engagement of PSGL-1 on neutrophils transduces signals that activate integrin LFA-1 to slow rolling on ICAM-1, thus augmenting neutrophil recruitment to inflammatory sites.<ref>Zarbock, A., Lowell, C. A., Ley, K. (2007) Spleen tyrosine kinase Syk is necessary for E-selectin-induced αLβ2 integrin-mediated rolling on intercellular adhesion molecule-1. Immunity 26, 773-783.</ref><ref>Zarbock, A., Abram, C. L., Hundt, M., Altman, A., Lowell, C. A., Ley, K. (2008) PSGL-1 engagement by E-selectin signals through Src kinase Fgr and ITAM adapters DAP12 and FcR gamma to induce slow leukocyte rolling. J Exp Med 205, 2339-2347.</ref><ref>Miner, J. J., Xia, L., Yago, T., Kappelmayer, J., Liu, Z., Klopocki, A. G., Shao, B., McDaniel, J. M., Setiadi, H., Schmidtke, D. W., McEver, R. P. (2008) Separable requirements for cytoplasmic domain of PSGL-1 in leukocyte rolling and signaling under flow. Blood 112, 2035-2045.</ref><ref>Yago, T., Shao, B., Miner, J. J., Yao, L., Klopocki, A. G., Maeda, K., Coggeshall, K. M., McEver, R. P. (2010) E-selectin engages PSGL-1 and CD44 through a common signaling pathway to induce integrin αLβ2-mediated slow leukocyte rolling. Blood March 18 [Epub ahead of print].</ref><ref>Mueller, H., Stadtmann, A., Van Aken, H., Hirsch, E., Wang, D., Ley, K., Zarbock, A. (2010) Tyrosine kinase Btk regulates E-selectin-mediated integrin activation and neutrophil recruitment by controlling phospholipase C (PLC) gamma2 and PI3Kgamma pathways. Blood 115, 3118-27.</ref>
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=P-selectin&maxresults=20 CFG database search results for P-selectin].

=== Glycan profiling ===
The glycans on the main target for P-selectin, P-selectin glycoprotein ligand 1 (PSGL-1), were analyzed.<ref name="Kawar2008">Kawar ZS, Johnson TK, Natunen S, Lowe JB, Cummings RD (2008) PSGL-1 from the murine leukocytic cell line WEHI-3 is enriched for core 2-based O-glycans with sialyl Lewis x antigen. Glycobiology 18, 441-446</ref>

=== Glycogene microarray ===
Probes for all three human and mouse selectins have been included in all versions of the CFG glycogene chip. Regulation of P-selectin expression was analyzed under multiple conditions; see all results [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=p-selectin&cat=coree here].

=== Knockout mouse lines ===
The [https://www.functionalglycomics.org/glycomics/publicdata/phenotyping.jsp phenotype] of PSGL-1 knockout mice was analyzed by the CFG. The CFG did not generate mice deficient in the P-selectin gene, as these mice were published in 1993<ref name="Mayadas 1993">Mayadas TN, Johnson RC, Rayburn H, Hynes RO, Wagner DD. Leukocyte rolling and extravasation are severely compromised in P selectin-deficient mice. Cell. 1993 Aug 13;74(3):541-54. PubMed PMID: 7688665.</ref> and have since been extensively studied. P-selectin knockout mice exhibit defects in leukocyte behavior, including elevated numbers of circulating neutrophils, loss of leukocyte rolling in mesenteric venules, and delayed neutrophil recruitment to the peritoneal cavity after induction of inflammation<ref name="Mayadas 1993"/>. They also show attentuated polymorphonuclear leukocyte accumulation and myocardial injury following brief ischaemia-reperfusion of the myocardium (i.e., P-selectin deficiency is cardioprotective; reviewed in <ref>Kakkar AK, Lefer DJ. Leukocyte and endothelial adhesion molecule studies in knockout mice. Curr Opin Pharmacol. 2004 Apr;4(2):154-8. Review. PubMed PMID:15063359.</ref>.)

=== Glycan array ===
The comparative binding specificities of [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1659 human] and [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1095 mouse] P-selectins have been analyzed. See all glycan array results for P-selectin [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=P-selectin&cat=coreh here].

== Related GBPs ==
L-selectin [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=L-selectin&maxresults=20 (CFG data)]and E-selectin [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=E-selectin&maxresults=20 (CFG data)].

== References ==
<references/>
* Mitoma J, Miyazaki T, Sutton-Smith M, Suzuki M, Saito H, Yeh JC, Kawano T, Hindsgaul O, Seeberger PH, Panico M, Haslam SM, Morris HR, Cummings RD, Dell A, Fukuda M (2009) The N-glycolyl form of mouse sialyl Lewis X is recognized by selectins but not by HECA-452 and FH6 antibodies that were raised against human cells. Glycoconj J 26, 511-523.
* Kawar ZS, Johnson TK, Natunen S, Lowe JB, Cummings RD (2008) PSGL-1 from the murine leukocytic cell line WEHI-3 is enriched for core 2-based O-glycans with sialyl Lewis x antigen. Glycobiology 18, 441-446.
* Mitoma J, Bao X, Petryanik B, Schaerli P, Gauguet JM, Yu SY, Kawashima H, Saito H, Ohtsubo K, Marth JD, Khoo KH, von Andrian UH, Lowe JB, Fukuda M (2007) Critical functions of N-glycans in L-selectin-mediated lymphocyte homing and recruitment. Nat Immunol 8, 409-418.
* Veerman KM, Williams MJ, Uchimura K, Singer MS, Merzaban JS, Naus S, Carlow DA, Owen P, Rivera-Nieves J, Rosen SD, Ziltener HJ (2007) Interaction of the selectin ligand PSGL-1 with chemokines CCL21 and CCL19 facilitates efficient homing of T cells to secondary lymphoid organs. Nat Immunol 8, 532-539.
* Chen S, Kawashima H, Lowe JB, Lanier LL, Fukuda M (2005) Suppression of tumor formation in lymph nodes by L-selectin-mediated natural killer cell recruitment. J Exp Med 202, 1679-1689.
* Kawashima H, Petryniak B, Hiraoka N, Mitoma J, Huckaby V, Nakayama J, Uchimura K, Kadomatsu K, Muramatsu T, Lowe JB, Fukuda M (2005) N-acetylglucosamine-6-O-sulfotransferases 1 and 2 cooperatively control lymphocyte homing through L-selectin ligand biosynthesis in high endothelial venules. Nat Immunol 6, 1096-1104.
* Piccio L, Rossi B, Colantonio L, Grenningloh R, Gho A, Ottoboni L, Homeister JW, Scarpini E, Martinello M, Laudanna C, DAmbrosio D, Lowe JB, (2005) Constantin G Efficient recruitment of lymphocytes in inflamed brain venules requires expression of cutaneous lymphocyte antigen and fucosyltransferase-VII. J Immunol 174, 5805-5813.
* Homeister JW, Daugherty A, Lowe JB (2004) α(1,3)Fucosyltransferases FucT-IV and FucT-VII control susceptibility to atherosclerosis in apolipoprotein E -/- mice. Arterioscler Thromb Vasc Biol 24, 1897-1903.
* Lowe JB (2003) Glycan-dependent leukocyte adhesion and recruitment in inflammation Curr Opin Cell Biol 15, 531-538.
* Smith PL, Myers JT, Rogers CE, Zhou L, Petryniak B, Becher DJ, Homeister JW, Lowe JB (2002) Conditional control of selectin ligand expression and global fucosylation events in mice with a targeted mutation at the FX locus. J Cell Biol 158, 801-815.

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Kurt Drickamer, Rodger McEver, Yvette van Kooyk

P-Selectin

2011-10-20T14:10:07Z

Kurt Drickamer: /* Biosynthesis of ligands */

The three selectins (P-selectin, L-selectin, and E-selectin) have related and sometimes overlapping functions in cell adhesion and mediate some of the best characterized glycan-dependent cell adhesion events. Of the ligands for these three C-type lectins, the target ligand of P-selectin, P-selectin glycoprotein ligand 1 (PSGL-1), is the best understood. Thus, P-selectin is used here to represent all three selectins.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
Selectin research was already at a relatively mature stage when the CFG began. Early PI work included structural studies, extensive analysis of leukocyte adhesion to endothelia ''in vivo'', and characterization of knockout mice to demonstrate physiological function. In addition to submitting samples for glycan array analysis, PIs have been involved in analyzing selectin expression under different conditions, including in knockout mice lacking enzymes for making target ligands.
* PIs working on P-selectin include: Hans-Peter Altevogt, Bruce Bochner, Pi-Wan Cheng, Richard Cummings, Robert Fuhlbrigge, Minoru Fukuda, Geoff Kansas, Klaus Ley, John Lowe, Rodger McEver, Steve Rosen, Ron Schnaar, Karen Snapp, Lloyd Stoolman, Martin Wild, Hermann Ziltener
* Non-PIs who have used CFG resources to study P-selectin include: Roland Contreras, Leonard Seymour

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about P-selectin, its carbohydrate ligands, and how they interact to mediate cell communication. Further information can be found in the GBP Molecule Pages for [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_hum_Ctlect_354&sideMenu=no human] and [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_mou_Ctlect_284&sideMenu=no mouse] P-selectin in the CFG database.
=== Carbohydrate ligands ===

P-selectin binds cooperatively to tyrosine sulfates, other amino acids, and a core 2 O-glycan capped with sialyl Lewis x, all positioned near the N terminus of PSGL-1<ref>Leppanen A, White SP, Helin J, McEver RP, Cummings RD (2000) Binding of glycosulfopeptides to P-selectin requires stereospecific contributions of individual tyrosine sulfate and sugar residues. J Biol Chem 275, 39569-39578.</ref>

=== Cellular expression of GBP and ligands ===

P-selectin is expressed on platelets, endothelial cells, and some macrophages
<ref name=" McEver RP 581">McEver RP (2002) Selectins: lectins that initiate cell adhesion under flow. Curr Opin Cell Biol 14, 581-588.</ref><ref>Tchernychev B, Furie B, Furie BC (2003) Peritoneal macrophages express both P-selectin and PSGL-1. J Cell Biol 163, 1145-1155</ref>. PSGL-1 is expressed on leukocytes and some endothelial cells<ref name=" McEver RP 581"></ref><ref>Rivera-Nieves J, Burcin TL, Olson TS, Morris MA, McDuffie M, Cominelli F, Ley K (2006) Critical role of endothelial P-selectin glycoprotein ligand 1 in chronic murine ileitis. J Clin Invest 203, 907-919</ref>.

=== Biosynthesis of ligands ===
SLeX (sialyl Lewis-X) like structures located on O-glycans at the N-terminus of PSGL-1 constitute the physiological ligands for all three members of the selectin family, L-, E- and P-selectin. Studies in which glycosyltransferases were reconstituted in heterologous cell types together with knockout mouse experiments suggest a role for [polypeptide α-GalNAcT ppGalNAcT-1 http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_483&sideMenu=true&pageType=general], core-1 β1,3GalactosylT T-synthase [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_447&sideMenu=true&pageType=general], core-2 β1,6GlcNAcT C2GnT-I [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_542&sideMenu=true&pageType=general], β1,4GalactosylT β4GalT-I [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_436&sideMenu=true&pageType=general], α(2,3)sialylT ST3GalT-IV [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_625&sideMenu=true&pageType=general] and α(1,3) fucosylTs (FTs), FTIV [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_601&sideMenu=true&pageType=general] and FTVII [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_604&sideMenu=true&pageType=general], in the synthesis of such structures. Sulfation of the peptide backbone by tyrosine sulfoT is also important for functional selectin ligand biosynthesis on PSGL-1. 

=== Structure ===
[[image:P-selectin.jpg]] 
The structures of a fragment of P-selectin containing the CRD and EGF domains in complex with a sialyl Lewisx-containing oligosaccharide as well as a glycopeptide from PSGL-1 that contains sulfated tyrosine residues have been determined.<ref name="Somers2000">Somers W. S., Tang J., Shaw G. D,. Camphausen R. T. (2000) Insights into the molecular basis of leukocyte tethering and rolling revealed by structures of P- and E-selectin bound to SLex and PSGL-1. Cell 103, 467-479</ref> The fucose residue of the sialyl Lewisx tetrasaccharide fits in the primary binding site and interacts with a Ca2+ bound to the protein, with secondary contacts to the galactose residue and electrostatic interactions with the carboxyl group of sialic acid. The EGF domain is located on the opposite side of the CRD from the glycan-binding site.
 

=== Biological roles of GBP-ligand interaction ===

Interactions between P-selectin and PSGL-1 initiate rolling of leukocytes on activated platelets and endothelial cells as one of the earliest responses to tissue injury and infection<ref>McEver, R. P. (2001) Adhesive interactions of leukocytes, platelets, and the vessel wall during hemostasis and inflammation. Thromb Haemost 86, 746-756.</ref><ref name=" McEver RP 581"></ref><ref>McEver, R. P. and Zhu, C. (2010) Rolling cell adhesion. Annu Rev Cell Dev Biol 26, in press.</ref>. Engagement of PSGL-1 on neutrophils transduces signals that activate integrin LFA-1 to slow rolling on ICAM-1, thus augmenting neutrophil recruitment to inflammatory sites.<ref>Zarbock, A., Lowell, C. A., Ley, K. (2007) Spleen tyrosine kinase Syk is necessary for E-selectin-induced αLβ2 integrin-mediated rolling on intercellular adhesion molecule-1. Immunity 26, 773-783.</ref><ref>Zarbock, A., Abram, C. L., Hundt, M., Altman, A., Lowell, C. A., Ley, K. (2008) PSGL-1 engagement by E-selectin signals through Src kinase Fgr and ITAM adapters DAP12 and FcR gamma to induce slow leukocyte rolling. J Exp Med 205, 2339-2347.</ref><ref>Miner, J. J., Xia, L., Yago, T., Kappelmayer, J., Liu, Z., Klopocki, A. G., Shao, B., McDaniel, J. M., Setiadi, H., Schmidtke, D. W., McEver, R. P. (2008) Separable requirements for cytoplasmic domain of PSGL-1 in leukocyte rolling and signaling under flow. Blood 112, 2035-2045.</ref><ref>Yago, T., Shao, B., Miner, J. J., Yao, L., Klopocki, A. G., Maeda, K., Coggeshall, K. M., McEver, R. P. (2010) E-selectin engages PSGL-1 and CD44 through a common signaling pathway to induce integrin αLβ2-mediated slow leukocyte rolling. Blood March 18 [Epub ahead of print].</ref><ref>Mueller, H., Stadtmann, A., Van Aken, H., Hirsch, E., Wang, D., Ley, K., Zarbock, A. (2010) Tyrosine kinase Btk regulates E-selectin-mediated integrin activation and neutrophil recruitment by controlling phospholipase C (PLC) gamma2 and PI3Kgamma pathways. Blood 115, 3118-27.</ref>
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=P-selectin&maxresults=20 CFG database search results for P-selectin].

=== Glycan profiling ===
The glycans on the main target for P-selectin, P-selectin glycoprotein ligand 1 (PSGL-1), were analyzed.<ref name="Kawar2008">Kawar ZS, Johnson TK, Natunen S, Lowe JB, Cummings RD (2008) PSGL-1 from the murine leukocytic cell line WEHI-3 is enriched for core 2-based O-glycans with sialyl Lewis x antigen. Glycobiology 18, 441-446</ref>

=== Glycogene microarray ===
Probes for all three human and mouse selectins have been included in all versions of the CFG glycogene chip. Regulation of P-selectin expression was analyzed under multiple conditions; see all results [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=p-selectin&cat=coree here].

=== Knockout mouse lines ===
The [https://www.functionalglycomics.org/glycomics/publicdata/phenotyping.jsp phenotype] of PSGL-1 knockout mice was analyzed by the CFG. The CFG did not generate mice deficient in the P-selectin gene, as these mice were published in 1993<ref name="Mayadas 1993">Mayadas TN, Johnson RC, Rayburn H, Hynes RO, Wagner DD. Leukocyte rolling and extravasation are severely compromised in P selectin-deficient mice. Cell. 1993 Aug 13;74(3):541-54. PubMed PMID: 7688665.</ref> and have since been extensively studied. P-selectin knockout mice exhibit defects in leukocyte behavior, including elevated numbers of circulating neutrophils, loss of leukocyte rolling in mesenteric venules, and delayed neutrophil recruitment to the peritoneal cavity after induction of inflammation<ref name="Mayadas 1993"/>. They also show attentuated polymorphonuclear leukocyte accumulation and myocardial injury following brief ischaemia-reperfusion of the myocardium (i.e., P-selectin deficiency is cardioprotective; reviewed in <ref>Kakkar AK, Lefer DJ. Leukocyte and endothelial adhesion molecule studies in knockout mice. Curr Opin Pharmacol. 2004 Apr;4(2):154-8. Review. PubMed PMID:15063359.</ref>.)

=== Glycan array ===
The comparative binding specificities of [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1659 human] and [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1095 mouse] P-selectins have been analyzed. See all glycan array results for P-selectin [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=P-selectin&cat=coreh here].

== Related GBPs ==
L-selectin [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=L-selectin&maxresults=20 (CFG data)]and E-selectin [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=E-selectin&maxresults=20 (CFG data)].

== References ==
<references/>
* Mitoma J, Miyazaki T, Sutton-Smith M, Suzuki M, Saito H, Yeh JC, Kawano T, Hindsgaul O, Seeberger PH, Panico M, Haslam SM, Morris HR, Cummings RD, Dell A, Fukuda M (2009) The N-glycolyl form of mouse sialyl Lewis X is recognized by selectins but not by HECA-452 and FH6 antibodies that were raised against human cells. Glycoconj J 26, 511-523.
* Kawar ZS, Johnson TK, Natunen S, Lowe JB, Cummings RD (2008) PSGL-1 from the murine leukocytic cell line WEHI-3 is enriched for core 2-based O-glycans with sialyl Lewis x antigen. Glycobiology 18, 441-446.
* Mitoma J, Bao X, Petryanik B, Schaerli P, Gauguet JM, Yu SY, Kawashima H, Saito H, Ohtsubo K, Marth JD, Khoo KH, von Andrian UH, Lowe JB, Fukuda M (2007) Critical functions of N-glycans in L-selectin-mediated lymphocyte homing and recruitment. Nat Immunol 8, 409-418.
* Veerman KM, Williams MJ, Uchimura K, Singer MS, Merzaban JS, Naus S, Carlow DA, Owen P, Rivera-Nieves J, Rosen SD, Ziltener HJ (2007) Interaction of the selectin ligand PSGL-1 with chemokines CCL21 and CCL19 facilitates efficient homing of T cells to secondary lymphoid organs. Nat Immunol 8, 532-539.
* Chen S, Kawashima H, Lowe JB, Lanier LL, Fukuda M (2005) Suppression of tumor formation in lymph nodes by L-selectin-mediated natural killer cell recruitment. J Exp Med 202, 1679-1689.
* Kawashima H, Petryniak B, Hiraoka N, Mitoma J, Huckaby V, Nakayama J, Uchimura K, Kadomatsu K, Muramatsu T, Lowe JB, Fukuda M (2005) N-acetylglucosamine-6-O-sulfotransferases 1 and 2 cooperatively control lymphocyte homing through L-selectin ligand biosynthesis in high endothelial venules. Nat Immunol 6, 1096-1104.
* Piccio L, Rossi B, Colantonio L, Grenningloh R, Gho A, Ottoboni L, Homeister JW, Scarpini E, Martinello M, Laudanna C, DAmbrosio D, Lowe JB, (2005) Constantin G Efficient recruitment of lymphocytes in inflamed brain venules requires expression of cutaneous lymphocyte antigen and fucosyltransferase-VII. J Immunol 174, 5805-5813.
* Homeister JW, Daugherty A, Lowe JB (2004) α(1,3)Fucosyltransferases FucT-IV and FucT-VII control susceptibility to atherosclerosis in apolipoprotein E -/- mice. Arterioscler Thromb Vasc Biol 24, 1897-1903.
* Lowe JB (2003) Glycan-dependent leukocyte adhesion and recruitment in inflammation Curr Opin Cell Biol 15, 531-538.
* Smith PL, Myers JT, Rogers CE, Zhou L, Petryniak B, Becher DJ, Homeister JW, Lowe JB (2002) Conditional control of selectin ligand expression and global fucosylation events in mice with a targeted mutation at the FX locus. J Cell Biol 158, 801-815.

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Kurt Drickamer, Rodger McEver, Yvette van Kooyk

P-Selectin

2011-10-20T14:09:30Z

Kurt Drickamer: /* Biosynthesis of ligands */

The three selectins (P-selectin, L-selectin, and E-selectin) have related and sometimes overlapping functions in cell adhesion and mediate some of the best characterized glycan-dependent cell adhesion events. Of the ligands for these three C-type lectins, the target ligand of P-selectin, P-selectin glycoprotein ligand 1 (PSGL-1), is the best understood. Thus, P-selectin is used here to represent all three selectins.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
Selectin research was already at a relatively mature stage when the CFG began. Early PI work included structural studies, extensive analysis of leukocyte adhesion to endothelia ''in vivo'', and characterization of knockout mice to demonstrate physiological function. In addition to submitting samples for glycan array analysis, PIs have been involved in analyzing selectin expression under different conditions, including in knockout mice lacking enzymes for making target ligands.
* PIs working on P-selectin include: Hans-Peter Altevogt, Bruce Bochner, Pi-Wan Cheng, Richard Cummings, Robert Fuhlbrigge, Minoru Fukuda, Geoff Kansas, Klaus Ley, John Lowe, Rodger McEver, Steve Rosen, Ron Schnaar, Karen Snapp, Lloyd Stoolman, Martin Wild, Hermann Ziltener
* Non-PIs who have used CFG resources to study P-selectin include: Roland Contreras, Leonard Seymour

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about P-selectin, its carbohydrate ligands, and how they interact to mediate cell communication. Further information can be found in the GBP Molecule Pages for [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_hum_Ctlect_354&sideMenu=no human] and [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_mou_Ctlect_284&sideMenu=no mouse] P-selectin in the CFG database.
=== Carbohydrate ligands ===

P-selectin binds cooperatively to tyrosine sulfates, other amino acids, and a core 2 O-glycan capped with sialyl Lewis x, all positioned near the N terminus of PSGL-1<ref>Leppanen A, White SP, Helin J, McEver RP, Cummings RD (2000) Binding of glycosulfopeptides to P-selectin requires stereospecific contributions of individual tyrosine sulfate and sugar residues. J Biol Chem 275, 39569-39578.</ref>

=== Cellular expression of GBP and ligands ===

P-selectin is expressed on platelets, endothelial cells, and some macrophages
<ref name=" McEver RP 581">McEver RP (2002) Selectins: lectins that initiate cell adhesion under flow. Curr Opin Cell Biol 14, 581-588.</ref><ref>Tchernychev B, Furie B, Furie BC (2003) Peritoneal macrophages express both P-selectin and PSGL-1. J Cell Biol 163, 1145-1155</ref>. PSGL-1 is expressed on leukocytes and some endothelial cells<ref name=" McEver RP 581"></ref><ref>Rivera-Nieves J, Burcin TL, Olson TS, Morris MA, McDuffie M, Cominelli F, Ley K (2006) Critical role of endothelial P-selectin glycoprotein ligand 1 in chronic murine ileitis. J Clin Invest 203, 907-919</ref>.

=== Biosynthesis of ligands ===
SLeX (sialyl Lewis-X) like structures located on O-glycans at the N-terminus of PSGL-1 constitute the physiological ligands for all three members of the selectin family, L-, E- and P-selectin. Studies in which glycosyltransferases were reconstituted in heterologous cell types together with knockout mouse experiments suggest a role for polypeptide α-GalNAcT ppGalNAcT-1[http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_483&sideMenu=true&pageType=general], core-1 β1,3GalactosylT T-synthase [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_447&sideMenu=true&pageType=general], core-2 β1,6GlcNAcT C2GnT-I [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_542&sideMenu=true&pageType=general], β1,4GalactosylT β4GalT-I [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_436&sideMenu=true&pageType=general], α(2,3)sialylT ST3GalT-IV [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_625&sideMenu=true&pageType=general] and α(1,3) fucosylTs (FTs), FTIV [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_601&sideMenu=true&pageType=general] and FTVII [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_604&sideMenu=true&pageType=general], in the synthesis of such structures. Sulfation of the peptide backbone by tyrosine sulfoT is also important for functional selectin ligand biosynthesis on PSGL-1. 

=== Structure ===
[[image:P-selectin.jpg]] 
The structures of a fragment of P-selectin containing the CRD and EGF domains in complex with a sialyl Lewisx-containing oligosaccharide as well as a glycopeptide from PSGL-1 that contains sulfated tyrosine residues have been determined.<ref name="Somers2000">Somers W. S., Tang J., Shaw G. D,. Camphausen R. T. (2000) Insights into the molecular basis of leukocyte tethering and rolling revealed by structures of P- and E-selectin bound to SLex and PSGL-1. Cell 103, 467-479</ref> The fucose residue of the sialyl Lewisx tetrasaccharide fits in the primary binding site and interacts with a Ca2+ bound to the protein, with secondary contacts to the galactose residue and electrostatic interactions with the carboxyl group of sialic acid. The EGF domain is located on the opposite side of the CRD from the glycan-binding site.
 

=== Biological roles of GBP-ligand interaction ===

Interactions between P-selectin and PSGL-1 initiate rolling of leukocytes on activated platelets and endothelial cells as one of the earliest responses to tissue injury and infection<ref>McEver, R. P. (2001) Adhesive interactions of leukocytes, platelets, and the vessel wall during hemostasis and inflammation. Thromb Haemost 86, 746-756.</ref><ref name=" McEver RP 581"></ref><ref>McEver, R. P. and Zhu, C. (2010) Rolling cell adhesion. Annu Rev Cell Dev Biol 26, in press.</ref>. Engagement of PSGL-1 on neutrophils transduces signals that activate integrin LFA-1 to slow rolling on ICAM-1, thus augmenting neutrophil recruitment to inflammatory sites.<ref>Zarbock, A., Lowell, C. A., Ley, K. (2007) Spleen tyrosine kinase Syk is necessary for E-selectin-induced αLβ2 integrin-mediated rolling on intercellular adhesion molecule-1. Immunity 26, 773-783.</ref><ref>Zarbock, A., Abram, C. L., Hundt, M., Altman, A., Lowell, C. A., Ley, K. (2008) PSGL-1 engagement by E-selectin signals through Src kinase Fgr and ITAM adapters DAP12 and FcR gamma to induce slow leukocyte rolling. J Exp Med 205, 2339-2347.</ref><ref>Miner, J. J., Xia, L., Yago, T., Kappelmayer, J., Liu, Z., Klopocki, A. G., Shao, B., McDaniel, J. M., Setiadi, H., Schmidtke, D. W., McEver, R. P. (2008) Separable requirements for cytoplasmic domain of PSGL-1 in leukocyte rolling and signaling under flow. Blood 112, 2035-2045.</ref><ref>Yago, T., Shao, B., Miner, J. J., Yao, L., Klopocki, A. G., Maeda, K., Coggeshall, K. M., McEver, R. P. (2010) E-selectin engages PSGL-1 and CD44 through a common signaling pathway to induce integrin αLβ2-mediated slow leukocyte rolling. Blood March 18 [Epub ahead of print].</ref><ref>Mueller, H., Stadtmann, A., Van Aken, H., Hirsch, E., Wang, D., Ley, K., Zarbock, A. (2010) Tyrosine kinase Btk regulates E-selectin-mediated integrin activation and neutrophil recruitment by controlling phospholipase C (PLC) gamma2 and PI3Kgamma pathways. Blood 115, 3118-27.</ref>
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=P-selectin&maxresults=20 CFG database search results for P-selectin].

=== Glycan profiling ===
The glycans on the main target for P-selectin, P-selectin glycoprotein ligand 1 (PSGL-1), were analyzed.<ref name="Kawar2008">Kawar ZS, Johnson TK, Natunen S, Lowe JB, Cummings RD (2008) PSGL-1 from the murine leukocytic cell line WEHI-3 is enriched for core 2-based O-glycans with sialyl Lewis x antigen. Glycobiology 18, 441-446</ref>

=== Glycogene microarray ===
Probes for all three human and mouse selectins have been included in all versions of the CFG glycogene chip. Regulation of P-selectin expression was analyzed under multiple conditions; see all results [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=p-selectin&cat=coree here].

=== Knockout mouse lines ===
The [https://www.functionalglycomics.org/glycomics/publicdata/phenotyping.jsp phenotype] of PSGL-1 knockout mice was analyzed by the CFG. The CFG did not generate mice deficient in the P-selectin gene, as these mice were published in 1993<ref name="Mayadas 1993">Mayadas TN, Johnson RC, Rayburn H, Hynes RO, Wagner DD. Leukocyte rolling and extravasation are severely compromised in P selectin-deficient mice. Cell. 1993 Aug 13;74(3):541-54. PubMed PMID: 7688665.</ref> and have since been extensively studied. P-selectin knockout mice exhibit defects in leukocyte behavior, including elevated numbers of circulating neutrophils, loss of leukocyte rolling in mesenteric venules, and delayed neutrophil recruitment to the peritoneal cavity after induction of inflammation<ref name="Mayadas 1993"/>. They also show attentuated polymorphonuclear leukocyte accumulation and myocardial injury following brief ischaemia-reperfusion of the myocardium (i.e., P-selectin deficiency is cardioprotective; reviewed in <ref>Kakkar AK, Lefer DJ. Leukocyte and endothelial adhesion molecule studies in knockout mice. Curr Opin Pharmacol. 2004 Apr;4(2):154-8. Review. PubMed PMID:15063359.</ref>.)

=== Glycan array ===
The comparative binding specificities of [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1659 human] and [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1095 mouse] P-selectins have been analyzed. See all glycan array results for P-selectin [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=P-selectin&cat=coreh here].

== Related GBPs ==
L-selectin [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=L-selectin&maxresults=20 (CFG data)]and E-selectin [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=E-selectin&maxresults=20 (CFG data)].

== References ==
<references/>
* Mitoma J, Miyazaki T, Sutton-Smith M, Suzuki M, Saito H, Yeh JC, Kawano T, Hindsgaul O, Seeberger PH, Panico M, Haslam SM, Morris HR, Cummings RD, Dell A, Fukuda M (2009) The N-glycolyl form of mouse sialyl Lewis X is recognized by selectins but not by HECA-452 and FH6 antibodies that were raised against human cells. Glycoconj J 26, 511-523.
* Kawar ZS, Johnson TK, Natunen S, Lowe JB, Cummings RD (2008) PSGL-1 from the murine leukocytic cell line WEHI-3 is enriched for core 2-based O-glycans with sialyl Lewis x antigen. Glycobiology 18, 441-446.
* Mitoma J, Bao X, Petryanik B, Schaerli P, Gauguet JM, Yu SY, Kawashima H, Saito H, Ohtsubo K, Marth JD, Khoo KH, von Andrian UH, Lowe JB, Fukuda M (2007) Critical functions of N-glycans in L-selectin-mediated lymphocyte homing and recruitment. Nat Immunol 8, 409-418.
* Veerman KM, Williams MJ, Uchimura K, Singer MS, Merzaban JS, Naus S, Carlow DA, Owen P, Rivera-Nieves J, Rosen SD, Ziltener HJ (2007) Interaction of the selectin ligand PSGL-1 with chemokines CCL21 and CCL19 facilitates efficient homing of T cells to secondary lymphoid organs. Nat Immunol 8, 532-539.
* Chen S, Kawashima H, Lowe JB, Lanier LL, Fukuda M (2005) Suppression of tumor formation in lymph nodes by L-selectin-mediated natural killer cell recruitment. J Exp Med 202, 1679-1689.
* Kawashima H, Petryniak B, Hiraoka N, Mitoma J, Huckaby V, Nakayama J, Uchimura K, Kadomatsu K, Muramatsu T, Lowe JB, Fukuda M (2005) N-acetylglucosamine-6-O-sulfotransferases 1 and 2 cooperatively control lymphocyte homing through L-selectin ligand biosynthesis in high endothelial venules. Nat Immunol 6, 1096-1104.
* Piccio L, Rossi B, Colantonio L, Grenningloh R, Gho A, Ottoboni L, Homeister JW, Scarpini E, Martinello M, Laudanna C, DAmbrosio D, Lowe JB, (2005) Constantin G Efficient recruitment of lymphocytes in inflamed brain venules requires expression of cutaneous lymphocyte antigen and fucosyltransferase-VII. J Immunol 174, 5805-5813.
* Homeister JW, Daugherty A, Lowe JB (2004) α(1,3)Fucosyltransferases FucT-IV and FucT-VII control susceptibility to atherosclerosis in apolipoprotein E -/- mice. Arterioscler Thromb Vasc Biol 24, 1897-1903.
* Lowe JB (2003) Glycan-dependent leukocyte adhesion and recruitment in inflammation Curr Opin Cell Biol 15, 531-538.
* Smith PL, Myers JT, Rogers CE, Zhou L, Petryniak B, Becher DJ, Homeister JW, Lowe JB (2002) Conditional control of selectin ligand expression and global fucosylation events in mice with a targeted mutation at the FX locus. J Cell Biol 158, 801-815.

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Kurt Drickamer, Rodger McEver, Yvette van Kooyk

P-Selectin

2011-10-20T14:07:14Z

Kurt Drickamer: /* Biosynthesis of ligands */

The three selectins (P-selectin, L-selectin, and E-selectin) have related and sometimes overlapping functions in cell adhesion and mediate some of the best characterized glycan-dependent cell adhesion events. Of the ligands for these three C-type lectins, the target ligand of P-selectin, P-selectin glycoprotein ligand 1 (PSGL-1), is the best understood. Thus, P-selectin is used here to represent all three selectins.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
Selectin research was already at a relatively mature stage when the CFG began. Early PI work included structural studies, extensive analysis of leukocyte adhesion to endothelia ''in vivo'', and characterization of knockout mice to demonstrate physiological function. In addition to submitting samples for glycan array analysis, PIs have been involved in analyzing selectin expression under different conditions, including in knockout mice lacking enzymes for making target ligands.
* PIs working on P-selectin include: Hans-Peter Altevogt, Bruce Bochner, Pi-Wan Cheng, Richard Cummings, Robert Fuhlbrigge, Minoru Fukuda, Geoff Kansas, Klaus Ley, John Lowe, Rodger McEver, Steve Rosen, Ron Schnaar, Karen Snapp, Lloyd Stoolman, Martin Wild, Hermann Ziltener
* Non-PIs who have used CFG resources to study P-selectin include: Roland Contreras, Leonard Seymour

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about P-selectin, its carbohydrate ligands, and how they interact to mediate cell communication. Further information can be found in the GBP Molecule Pages for [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_hum_Ctlect_354&sideMenu=no human] and [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_mou_Ctlect_284&sideMenu=no mouse] P-selectin in the CFG database.
=== Carbohydrate ligands ===

P-selectin binds cooperatively to tyrosine sulfates, other amino acids, and a core 2 O-glycan capped with sialyl Lewis x, all positioned near the N terminus of PSGL-1<ref>Leppanen A, White SP, Helin J, McEver RP, Cummings RD (2000) Binding of glycosulfopeptides to P-selectin requires stereospecific contributions of individual tyrosine sulfate and sugar residues. J Biol Chem 275, 39569-39578.</ref>

=== Cellular expression of GBP and ligands ===

P-selectin is expressed on platelets, endothelial cells, and some macrophages
<ref name=" McEver RP 581">McEver RP (2002) Selectins: lectins that initiate cell adhesion under flow. Curr Opin Cell Biol 14, 581-588.</ref><ref>Tchernychev B, Furie B, Furie BC (2003) Peritoneal macrophages express both P-selectin and PSGL-1. J Cell Biol 163, 1145-1155</ref>. PSGL-1 is expressed on leukocytes and some endothelial cells<ref name=" McEver RP 581"></ref><ref>Rivera-Nieves J, Burcin TL, Olson TS, Morris MA, McDuffie M, Cominelli F, Ley K (2006) Critical role of endothelial P-selectin glycoprotein ligand 1 in chronic murine ileitis. J Clin Invest 203, 907-919</ref>.

=== Biosynthesis of ligands ===
SLeX (sialyl Lewis-X) like structures located on O-glycans at the N-terminus of PSGL-1 constitute the physiological ligands for all three members of the selectin family, L-, E- and P-selectin. Studies in which glycosyltransferases were reconstituted in heterologous cell types together with knockout mouse experiments suggest a role for polypeptide α-GalNAcT ppGalNAcT-1 [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_483&sideMenu=true&pageType=general], core-1 β1,3GalactosylT T-synthase [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_447&sideMenu=true&pageType=general], core-2 β1,6GlcNAcT C2GnT-I [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_542&sideMenu=true&pageType=general], β1,4GalactosylT β4GalT-I [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_436&sideMenu=true&pageType=general], α(2,3)sialylT ST3GalT-IV [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_625&sideMenu=true&pageType=general] and α(1,3) fucosylTs (FTs), FTIV [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_601&sideMenu=true&pageType=general] and FTVII [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_604&sideMenu=true&pageType=general], in the synthesis of such structures. Sulfation of the peptide backbone by tyrosine sulfoT is also important for functional selectin ligand biosynthesis on PSGL-1. 

=== Structure ===
[[image:P-selectin.jpg]] 
The structures of a fragment of P-selectin containing the CRD and EGF domains in complex with a sialyl Lewisx-containing oligosaccharide as well as a glycopeptide from PSGL-1 that contains sulfated tyrosine residues have been determined.<ref name="Somers2000">Somers W. S., Tang J., Shaw G. D,. Camphausen R. T. (2000) Insights into the molecular basis of leukocyte tethering and rolling revealed by structures of P- and E-selectin bound to SLex and PSGL-1. Cell 103, 467-479</ref> The fucose residue of the sialyl Lewisx tetrasaccharide fits in the primary binding site and interacts with a Ca2+ bound to the protein, with secondary contacts to the galactose residue and electrostatic interactions with the carboxyl group of sialic acid. The EGF domain is located on the opposite side of the CRD from the glycan-binding site.
 

=== Biological roles of GBP-ligand interaction ===

Interactions between P-selectin and PSGL-1 initiate rolling of leukocytes on activated platelets and endothelial cells as one of the earliest responses to tissue injury and infection<ref>McEver, R. P. (2001) Adhesive interactions of leukocytes, platelets, and the vessel wall during hemostasis and inflammation. Thromb Haemost 86, 746-756.</ref><ref name=" McEver RP 581"></ref><ref>McEver, R. P. and Zhu, C. (2010) Rolling cell adhesion. Annu Rev Cell Dev Biol 26, in press.</ref>. Engagement of PSGL-1 on neutrophils transduces signals that activate integrin LFA-1 to slow rolling on ICAM-1, thus augmenting neutrophil recruitment to inflammatory sites.<ref>Zarbock, A., Lowell, C. A., Ley, K. (2007) Spleen tyrosine kinase Syk is necessary for E-selectin-induced αLβ2 integrin-mediated rolling on intercellular adhesion molecule-1. Immunity 26, 773-783.</ref><ref>Zarbock, A., Abram, C. L., Hundt, M., Altman, A., Lowell, C. A., Ley, K. (2008) PSGL-1 engagement by E-selectin signals through Src kinase Fgr and ITAM adapters DAP12 and FcR gamma to induce slow leukocyte rolling. J Exp Med 205, 2339-2347.</ref><ref>Miner, J. J., Xia, L., Yago, T., Kappelmayer, J., Liu, Z., Klopocki, A. G., Shao, B., McDaniel, J. M., Setiadi, H., Schmidtke, D. W., McEver, R. P. (2008) Separable requirements for cytoplasmic domain of PSGL-1 in leukocyte rolling and signaling under flow. Blood 112, 2035-2045.</ref><ref>Yago, T., Shao, B., Miner, J. J., Yao, L., Klopocki, A. G., Maeda, K., Coggeshall, K. M., McEver, R. P. (2010) E-selectin engages PSGL-1 and CD44 through a common signaling pathway to induce integrin αLβ2-mediated slow leukocyte rolling. Blood March 18 [Epub ahead of print].</ref><ref>Mueller, H., Stadtmann, A., Van Aken, H., Hirsch, E., Wang, D., Ley, K., Zarbock, A. (2010) Tyrosine kinase Btk regulates E-selectin-mediated integrin activation and neutrophil recruitment by controlling phospholipase C (PLC) gamma2 and PI3Kgamma pathways. Blood 115, 3118-27.</ref>
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=P-selectin&maxresults=20 CFG database search results for P-selectin].

=== Glycan profiling ===
The glycans on the main target for P-selectin, P-selectin glycoprotein ligand 1 (PSGL-1), were analyzed.<ref name="Kawar2008">Kawar ZS, Johnson TK, Natunen S, Lowe JB, Cummings RD (2008) PSGL-1 from the murine leukocytic cell line WEHI-3 is enriched for core 2-based O-glycans with sialyl Lewis x antigen. Glycobiology 18, 441-446</ref>

=== Glycogene microarray ===
Probes for all three human and mouse selectins have been included in all versions of the CFG glycogene chip. Regulation of P-selectin expression was analyzed under multiple conditions; see all results [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=p-selectin&cat=coree here].

=== Knockout mouse lines ===
The [https://www.functionalglycomics.org/glycomics/publicdata/phenotyping.jsp phenotype] of PSGL-1 knockout mice was analyzed by the CFG. The CFG did not generate mice deficient in the P-selectin gene, as these mice were published in 1993<ref name="Mayadas 1993">Mayadas TN, Johnson RC, Rayburn H, Hynes RO, Wagner DD. Leukocyte rolling and extravasation are severely compromised in P selectin-deficient mice. Cell. 1993 Aug 13;74(3):541-54. PubMed PMID: 7688665.</ref> and have since been extensively studied. P-selectin knockout mice exhibit defects in leukocyte behavior, including elevated numbers of circulating neutrophils, loss of leukocyte rolling in mesenteric venules, and delayed neutrophil recruitment to the peritoneal cavity after induction of inflammation<ref name="Mayadas 1993"/>. They also show attentuated polymorphonuclear leukocyte accumulation and myocardial injury following brief ischaemia-reperfusion of the myocardium (i.e., P-selectin deficiency is cardioprotective; reviewed in <ref>Kakkar AK, Lefer DJ. Leukocyte and endothelial adhesion molecule studies in knockout mice. Curr Opin Pharmacol. 2004 Apr;4(2):154-8. Review. PubMed PMID:15063359.</ref>.)

=== Glycan array ===
The comparative binding specificities of [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1659 human] and [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1095 mouse] P-selectins have been analyzed. See all glycan array results for P-selectin [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=P-selectin&cat=coreh here].

== Related GBPs ==
L-selectin [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=L-selectin&maxresults=20 (CFG data)]and E-selectin [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=E-selectin&maxresults=20 (CFG data)].

== References ==
<references/>
* Mitoma J, Miyazaki T, Sutton-Smith M, Suzuki M, Saito H, Yeh JC, Kawano T, Hindsgaul O, Seeberger PH, Panico M, Haslam SM, Morris HR, Cummings RD, Dell A, Fukuda M (2009) The N-glycolyl form of mouse sialyl Lewis X is recognized by selectins but not by HECA-452 and FH6 antibodies that were raised against human cells. Glycoconj J 26, 511-523.
* Kawar ZS, Johnson TK, Natunen S, Lowe JB, Cummings RD (2008) PSGL-1 from the murine leukocytic cell line WEHI-3 is enriched for core 2-based O-glycans with sialyl Lewis x antigen. Glycobiology 18, 441-446.
* Mitoma J, Bao X, Petryanik B, Schaerli P, Gauguet JM, Yu SY, Kawashima H, Saito H, Ohtsubo K, Marth JD, Khoo KH, von Andrian UH, Lowe JB, Fukuda M (2007) Critical functions of N-glycans in L-selectin-mediated lymphocyte homing and recruitment. Nat Immunol 8, 409-418.
* Veerman KM, Williams MJ, Uchimura K, Singer MS, Merzaban JS, Naus S, Carlow DA, Owen P, Rivera-Nieves J, Rosen SD, Ziltener HJ (2007) Interaction of the selectin ligand PSGL-1 with chemokines CCL21 and CCL19 facilitates efficient homing of T cells to secondary lymphoid organs. Nat Immunol 8, 532-539.
* Chen S, Kawashima H, Lowe JB, Lanier LL, Fukuda M (2005) Suppression of tumor formation in lymph nodes by L-selectin-mediated natural killer cell recruitment. J Exp Med 202, 1679-1689.
* Kawashima H, Petryniak B, Hiraoka N, Mitoma J, Huckaby V, Nakayama J, Uchimura K, Kadomatsu K, Muramatsu T, Lowe JB, Fukuda M (2005) N-acetylglucosamine-6-O-sulfotransferases 1 and 2 cooperatively control lymphocyte homing through L-selectin ligand biosynthesis in high endothelial venules. Nat Immunol 6, 1096-1104.
* Piccio L, Rossi B, Colantonio L, Grenningloh R, Gho A, Ottoboni L, Homeister JW, Scarpini E, Martinello M, Laudanna C, DAmbrosio D, Lowe JB, (2005) Constantin G Efficient recruitment of lymphocytes in inflamed brain venules requires expression of cutaneous lymphocyte antigen and fucosyltransferase-VII. J Immunol 174, 5805-5813.
* Homeister JW, Daugherty A, Lowe JB (2004) α(1,3)Fucosyltransferases FucT-IV and FucT-VII control susceptibility to atherosclerosis in apolipoprotein E -/- mice. Arterioscler Thromb Vasc Biol 24, 1897-1903.
* Lowe JB (2003) Glycan-dependent leukocyte adhesion and recruitment in inflammation Curr Opin Cell Biol 15, 531-538.
* Smith PL, Myers JT, Rogers CE, Zhou L, Petryniak B, Becher DJ, Homeister JW, Lowe JB (2002) Conditional control of selectin ligand expression and global fucosylation events in mice with a targeted mutation at the FX locus. J Cell Biol 158, 801-815.

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Kurt Drickamer, Rodger McEver, Yvette van Kooyk

PA-IIL

2011-10-09T09:29:44Z

Kurt Drickamer: /* Biosynthesis of ligands */

PA-IIL (Pseudomonas lectin II, LecB) is a cytoplasmic lectin produced in ''Pseudomonas aruginosa'' under the control of quorum sensing. It is a virulence factor involved in binding of human tissues such as epithelial lung of cystic fibrosis patients<ref name="Imberty 2004">Imberty, A., Wimmerova, M., Mitchell, E. P. & Gilboa-Garber, N. (2004). Structures of the lectins from Pseudomonas aeruginosa: Insights into molecular basis for host glycan recognition. Microb. Infect. 6, 222-229.</ref>. The role of PA-IIL in pathogenesis has been highlighted, since interfering with PA-IIL binding site reduces the mortality of ''P. aeruginosa'' induced-pneumonia in a murine model<ref name="Chemani 2009">Chemani, C., Imberty, A., de Bentzman, S., Pierre, P., Wimmerová, M., Guery, B. P. & Faure, K. (2009). Role of LecA and LecB lectins in Pseudomonas aeruginosa induced lung injury and effect of carbohydrates ligands. Infect. Immun. 77, 2065-2075.</ref>. The paradigm is unique among glycan-binding proteins (GBPs) in that it contains two cationic ions in the carbohydrate binding site that result in unusual high affinity for the carbohydrate target<ref>Loris, R., Tielker, D., Jaeger, K.-E. & Wyns, L. (2003). Structural basis of carbohydrate recognition by the lectin LecB from Pseudomonas aeruginosa. J. Mol. Biol. 331, 861-870.</ref><ref name="test 1">Mitchell, E., Houles, C., Sudakevitz, D., Wimmerova, M., Gautier, C., Pérez, S., Wu, A. M., Gilboa-Garber, N. & Imberty, A. (2002). Structural basis for oligosaccharide-mediated adhesion of Pseudomonas aeruginosa in the lungs of cystic fibrosis patients. Nature Struct. Biol. 9, 918-921.</ref><ref>Mitchell, E. P., Sabin, C., Šnajdrová, L., Pokorná, M., Perret, S., Gautier, C., Hofr, C., Gilboa-Garber, N., Koča, J., Wimmerová, M. & Imberty, A. (2005). High affinity fucose binding of Pseudomonas aeruginosa lectin PA-IIL: 1.0 Å resolution crystal structure of the complex combined with thermodynamics and computational chemistry approaches. Proteins: Struct. Funct. Bioinfo. 58, 735-748.</ref>. The preferred glycan ligand of PA-IIL is the trisaccharide Lewis a<ref name="test 2">Perret, S., Sabin, C., Dumon, C., Pokorná, M., Gautier, C., Galanina, O., Ilia, S., Bovin, N., Nicaise, M., Desmadril, M., Gilboa-Garber, N., Wimmerova, M., Mitchell, E. P. & Imberty, A. (2005). Structural basis for the interaction between human milk oligosaccharides and the bacterial lectin PA-IIL of Pseudomonas aeruginosa. Biochem. J. 389, 325-332.</ref>. PA-IIL-like lectins have been characterized in other opportunistic bacteria such as ''Ralstonia solanacearum''<ref>Sudakevitz, D., Kostlanova, N., Blatman-Jan, G., Mitchell, E. P., Lerrer, B., Wimmerova, M., Katcof, f. D. J., Imberty, A. & Gilboa-Garber, N. (2004). A new Ralstonia solanacearum high affinity mannose-binding lectin RS-IIL structurally resembling the Pseudomonas aeruginosa fucose-specific lectin PA-IIL. Mol. Microbiol. 52, 691-700.</ref>, ''Chromobacterium violaceum''<ref name="Pokorna 11">Pokorná, M., Cioci, G., Perret, S., Rebuffet, E., Kostlánová, N., Adam, J., Gilboa-Garber, N., Mitchell, E. P., Imberty, A. & Wimmerová, M. (2006). Unusual entropy driven affinity of Chromobacterium violaceum lectin CV-IIL towards fucose and mannose. Biochemistry 45, 7501-7510.</ref>, and ''Burkholderia cenocepacia''<ref>Lameignere, E., Malinovská, L., Sláviková, M., Duchaud, E., Mitchell, E. P., Varrot, A., Šedo, O., Imberty, A. & Wimmerová, M. (2008). Structural basis for mannose recognition by a lectin from opportunistic bacteria Burkholderia cenocepacia. Biochem. J. 411, 307-318.</ref><ref>Lameignere, E., Shiao, T. C., Roy, R., Wimmerová, M., Dubreuil, F., Varrot, A. & Imberty, A. (2010). Structural basis of the affinity for oligomannosides and analogs displayed by BC2L-A, a Burkholderia cenocepacia soluble lectin. Glycobiology 20, 87-98.</ref>, albeit with some variations in the fine specificity. Starting from the results obtained with the help of CFG tools, major efforts are devoided in collaboration with carbohydrate chemists in order to design anti-bacterial new glyco-derived compounds that bind to PA-IIL with high affinity<ref>Imberty, A., Chabre, Y. M. & Roy, R. (2008). Glycomimetics and glycodendrimers as high affinity microbial antiadhesins. Chemistry 14, 7490-7499.</ref>.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
CFG Participating Investigators (PIs) have made major contribution to the understanding of the structure/specificity relationship of PA-IIL and PA-IIL-like proteins. These include: Anne Imberty, Remy Loris, Michaela Wimmerova

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about PA-IIL, its carbohydrate ligand(s), and how they interact to mediate cell communication.
=== Carbohydrate ligands ===

PA-IIL is a fucose-specific lectin that also recognises mannose residues. 
The high affinity ligand for PA-IIL has been deduced from glycan microarray screening on the CFG microarray[http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_GLYCAN_v3_221_02142006#] to be Galβ1-4(Fucα1-4)GlcNAc [Lewis a] <ref name="test 1"></ref><ref name="test 2"></ref><ref>Marotte K, Sabin C, Preville C, Moume-Pymbock M, Wimmerova M, Mitchell EP, Imberty A, Roy R. (2008) X-ray Structures and thermodynamics of the interaction of PA-IIL from Pseudomonas aeruginosa with disaccharide derivatives. ChemMedChem 10,1328-1338.</ref>

[[File:lewisa.jpg]]

=== Cellular expression of GBP and ligands ===
PA-IIL is produced in ''Pseudomonas aruginosa,'' and binds ligands in human tissues, including epithelial lung.
 
=== Biosynthesis of ligands ===
Lewis a synthesis requires the addition of α1-4 fucose to the sub-terminal GlcNAc residue on a type 1 chain. Addition of the α1-4 fucose is catalyzed exclusively by fucosyltransferase FUT3 [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_600&sideMenu=true&pageType=general].
 

=== Structure ===
PA-IIL is a tetrameric lectin. Each monomer consists of a β-sandwich and contains two calcium ions that interact directly with the carbohydrate ligand. Crystal structures have been determined for PA-IIL alone, and its complex with fucose, with related monosaccharides, and with complex fucosylated oligosaccharides.

[[File:pa2ls.jpg]]
 
Information on crystal structures of PA-IIL and links to PDB are available at PA-IIL page of [http://www.cermav.cnrs.fr/cgi-bin/lectines/menu.cgi?Bacterial%20lectins+2-CA%20b-sandwich+Pseudomonas%20PA-IIL 3D-lectin database]

=== Biological roles of GBP-ligand interaction ===
PA-IIL, a virulence factor that binds human tissues such as epithelial lung of cystic fibrosis patients<ref name="Imberty 2004"/>, has roles in pathogenesis <ref name="Chemani 2009"/>.
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=PA-IIL&maxresults=20 CFG database search results for PA-IIL].

=== Glycan profiling ===

 
=== Glycogene microarray ===
PA-IIL is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
Not applicable.
 

=== Glycan array ===
The specificity of PA-IIl and related proteins was determined through glycan array analysis (click [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_PA_v2_230_02102006 here] and [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_GLYCAN_v3_221_02142006# here]).

== Related GBPs ==
CV-IIL [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=CV-IIL&maxresults=20 (CFG data)], RS-IIL [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=RS-IIL&cat=coreh (CFG data)], BC2L-A, BC2L-B [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BC2L-B&maxresults=20 (CFG data)], BC2L-C [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BC2L-C&maxresults=20 (CFG data)].

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Anne Imberty and Micha Wimmerova

PA-IIL

2011-10-09T09:29:03Z

Kurt Drickamer: /* Biosynthesis of ligands */

PA-IIL (Pseudomonas lectin II, LecB) is a cytoplasmic lectin produced in ''Pseudomonas aruginosa'' under the control of quorum sensing. It is a virulence factor involved in binding of human tissues such as epithelial lung of cystic fibrosis patients<ref name="Imberty 2004">Imberty, A., Wimmerova, M., Mitchell, E. P. & Gilboa-Garber, N. (2004). Structures of the lectins from Pseudomonas aeruginosa: Insights into molecular basis for host glycan recognition. Microb. Infect. 6, 222-229.</ref>. The role of PA-IIL in pathogenesis has been highlighted, since interfering with PA-IIL binding site reduces the mortality of ''P. aeruginosa'' induced-pneumonia in a murine model<ref name="Chemani 2009">Chemani, C., Imberty, A., de Bentzman, S., Pierre, P., Wimmerová, M., Guery, B. P. & Faure, K. (2009). Role of LecA and LecB lectins in Pseudomonas aeruginosa induced lung injury and effect of carbohydrates ligands. Infect. Immun. 77, 2065-2075.</ref>. The paradigm is unique among glycan-binding proteins (GBPs) in that it contains two cationic ions in the carbohydrate binding site that result in unusual high affinity for the carbohydrate target<ref>Loris, R., Tielker, D., Jaeger, K.-E. & Wyns, L. (2003). Structural basis of carbohydrate recognition by the lectin LecB from Pseudomonas aeruginosa. J. Mol. Biol. 331, 861-870.</ref><ref name="test 1">Mitchell, E., Houles, C., Sudakevitz, D., Wimmerova, M., Gautier, C., Pérez, S., Wu, A. M., Gilboa-Garber, N. & Imberty, A. (2002). Structural basis for oligosaccharide-mediated adhesion of Pseudomonas aeruginosa in the lungs of cystic fibrosis patients. Nature Struct. Biol. 9, 918-921.</ref><ref>Mitchell, E. P., Sabin, C., Šnajdrová, L., Pokorná, M., Perret, S., Gautier, C., Hofr, C., Gilboa-Garber, N., Koča, J., Wimmerová, M. & Imberty, A. (2005). High affinity fucose binding of Pseudomonas aeruginosa lectin PA-IIL: 1.0 Å resolution crystal structure of the complex combined with thermodynamics and computational chemistry approaches. Proteins: Struct. Funct. Bioinfo. 58, 735-748.</ref>. The preferred glycan ligand of PA-IIL is the trisaccharide Lewis a<ref name="test 2">Perret, S., Sabin, C., Dumon, C., Pokorná, M., Gautier, C., Galanina, O., Ilia, S., Bovin, N., Nicaise, M., Desmadril, M., Gilboa-Garber, N., Wimmerova, M., Mitchell, E. P. & Imberty, A. (2005). Structural basis for the interaction between human milk oligosaccharides and the bacterial lectin PA-IIL of Pseudomonas aeruginosa. Biochem. J. 389, 325-332.</ref>. PA-IIL-like lectins have been characterized in other opportunistic bacteria such as ''Ralstonia solanacearum''<ref>Sudakevitz, D., Kostlanova, N., Blatman-Jan, G., Mitchell, E. P., Lerrer, B., Wimmerova, M., Katcof, f. D. J., Imberty, A. & Gilboa-Garber, N. (2004). A new Ralstonia solanacearum high affinity mannose-binding lectin RS-IIL structurally resembling the Pseudomonas aeruginosa fucose-specific lectin PA-IIL. Mol. Microbiol. 52, 691-700.</ref>, ''Chromobacterium violaceum''<ref name="Pokorna 11">Pokorná, M., Cioci, G., Perret, S., Rebuffet, E., Kostlánová, N., Adam, J., Gilboa-Garber, N., Mitchell, E. P., Imberty, A. & Wimmerová, M. (2006). Unusual entropy driven affinity of Chromobacterium violaceum lectin CV-IIL towards fucose and mannose. Biochemistry 45, 7501-7510.</ref>, and ''Burkholderia cenocepacia''<ref>Lameignere, E., Malinovská, L., Sláviková, M., Duchaud, E., Mitchell, E. P., Varrot, A., Šedo, O., Imberty, A. & Wimmerová, M. (2008). Structural basis for mannose recognition by a lectin from opportunistic bacteria Burkholderia cenocepacia. Biochem. J. 411, 307-318.</ref><ref>Lameignere, E., Shiao, T. C., Roy, R., Wimmerová, M., Dubreuil, F., Varrot, A. & Imberty, A. (2010). Structural basis of the affinity for oligomannosides and analogs displayed by BC2L-A, a Burkholderia cenocepacia soluble lectin. Glycobiology 20, 87-98.</ref>, albeit with some variations in the fine specificity. Starting from the results obtained with the help of CFG tools, major efforts are devoided in collaboration with carbohydrate chemists in order to design anti-bacterial new glyco-derived compounds that bind to PA-IIL with high affinity<ref>Imberty, A., Chabre, Y. M. & Roy, R. (2008). Glycomimetics and glycodendrimers as high affinity microbial antiadhesins. Chemistry 14, 7490-7499.</ref>.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
CFG Participating Investigators (PIs) have made major contribution to the understanding of the structure/specificity relationship of PA-IIL and PA-IIL-like proteins. These include: Anne Imberty, Remy Loris, Michaela Wimmerova

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about PA-IIL, its carbohydrate ligand(s), and how they interact to mediate cell communication.
=== Carbohydrate ligands ===

PA-IIL is a fucose-specific lectin that also recognises mannose residues. 
The high affinity ligand for PA-IIL has been deduced from glycan microarray screening on the CFG microarray[http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_GLYCAN_v3_221_02142006#] to be Galβ1-4(Fucα1-4)GlcNAc [Lewis a] <ref name="test 1"></ref><ref name="test 2"></ref><ref>Marotte K, Sabin C, Preville C, Moume-Pymbock M, Wimmerova M, Mitchell EP, Imberty A, Roy R. (2008) X-ray Structures and thermodynamics of the interaction of PA-IIL from Pseudomonas aeruginosa with disaccharide derivatives. ChemMedChem 10,1328-1338.</ref>

[[File:lewisa.jpg]]

=== Cellular expression of GBP and ligands ===
PA-IIL is produced in ''Pseudomonas aruginosa,'' and binds ligands in human tissues, including epithelial lung.
 
=== Biosynthesis of ligands ===
Lewis a synthesis requires the addition of α1-4 fucose to the sub-terminal GlcNAc residue on a type 1 chain. Addition of the α1-4 fucose can be catalyzed by fucosyltransferase FUT3 [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_600&sideMenu=true&pageType=general].
 

=== Structure ===
PA-IIL is a tetrameric lectin. Each monomer consists of a β-sandwich and contains two calcium ions that interact directly with the carbohydrate ligand. Crystal structures have been determined for PA-IIL alone, and its complex with fucose, with related monosaccharides, and with complex fucosylated oligosaccharides.

[[File:pa2ls.jpg]]
 
Information on crystal structures of PA-IIL and links to PDB are available at PA-IIL page of [http://www.cermav.cnrs.fr/cgi-bin/lectines/menu.cgi?Bacterial%20lectins+2-CA%20b-sandwich+Pseudomonas%20PA-IIL 3D-lectin database]

=== Biological roles of GBP-ligand interaction ===
PA-IIL, a virulence factor that binds human tissues such as epithelial lung of cystic fibrosis patients<ref name="Imberty 2004"/>, has roles in pathogenesis <ref name="Chemani 2009"/>.
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=PA-IIL&maxresults=20 CFG database search results for PA-IIL].

=== Glycan profiling ===

 
=== Glycogene microarray ===
PA-IIL is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
Not applicable.
 

=== Glycan array ===
The specificity of PA-IIl and related proteins was determined through glycan array analysis (click [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_PA_v2_230_02102006 here] and [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_GLYCAN_v3_221_02142006# here]).

== Related GBPs ==
CV-IIL [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=CV-IIL&maxresults=20 (CFG data)], RS-IIL [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=RS-IIL&cat=coreh (CFG data)], BC2L-A, BC2L-B [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BC2L-B&maxresults=20 (CFG data)], BC2L-C [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BC2L-C&maxresults=20 (CFG data)].

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Anne Imberty and Micha Wimmerova

CBM47

2011-10-09T09:11:37Z

Kurt Drickamer: /* Biosynthesis of ligands */

Enzymes that degrade host glycans are increasingly being found as virulence factors in pathogenic bacteria<ref>Shelburne, S. A., Davenport, M. T., Keith, D. B. & Musser, J. M. (2008). The role of complex carbohydrate catabolism in the pathogenesis of invasive streptococci. Trends Microbiol 16, 318-25.</ref><ref name="Hava 16">Hava, D. L. & Camilli, A. (2002). Large-scale identification of serotype 4 Streptococcus pneumoniae virulence factors. Mol Microbiol 45, 1389-406.</ref>. A common property of extracellular glycan degrading enzymes found in such bacteria is multi-modularity; these enzymes often comprise a large number of modules with a variety of functions. The most common class of ancillary module are carbohydrate-binding modules (CBMs)<ref>Boraston, A. B., Bolam, D. N., Gilbert, H. J. & Davies, G. J. (2004). Carbohydrate-binding modules: fine tuning polysaccharide recognition. Biochem J 382, 769-782.</ref>, which are alternatively referred to as lectin-domains. These modules are responsible for targeting carbohydrate-degrading enzymes to a glycan substrate or, when the enzymes are attached to the bacterial cell-surface, likely also function to adhere the bacterium to a glycan<ref>Ficko-Blean, E., Gregg, K. J., Adams, J. J., Hehemann, J. H., Czjzek, M., Smith, S. P. & Boraston, A. B. (2009). Portrait of an enzyme, a complete structural analysis of a multimodular {beta}-N-acetylglucosaminidase from Clostridium perfringens. J Biol Chem 284, 9876-84.</ref>. The presence of these lectin-domains in multi-modular proteins and their contribution of glycan binding function to catalytically active proteins distinguishes these modules from other bacterial glycan-binding proteins (GBPs). The CBM47 modules from the ''Streptococcus pneumoniae'' enzyme SpGH98 (or "fucolectin-related protein") are specific to the Lewisy antigen<ref name ="Boraston 2006">Boraston, A. B., Wang, D. & Burke, R. D. (2006). Blood group antigen recognition by a Streptococcus pneumoniae virulence factor. J Biol Chem 281, 35263-35271.</ref>, which is quite rare among all GBPs, and function to target this enzyme to this antigen when present on epithelial cells<ref name="Higgins 2009">Higgins, M. A., Whitworth, G. E., El Warry, N., Randriantsoa, M., Samain, E., Burke, R. D., Vocadlo, D. J. & Boraston, A. B. (2009). Differential recognition and hydrolysis of host carbohydrate antigens by Streptococcus pneumoniae family 98 glycoside hydrolases. J Biol Chem 284, 26161-73.</ref>. Recognition and destruction of this antigen appears to be a critical process in pneumococcal virulence<ref name="Hava 16"/><ref name="Embry 2007">Embry, A., Hinojosa, E. & Orihuela, C. J. (2007). Regions of Diversity 8, 9 and 13 contribute to Streptococcus pneumoniae virulence. BMC Microbiol 7, 80.</ref>.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
This is a very new area of investigation. CFG Participating Investigators (PIs) that have screened other CBMs or proteins containing CBMs include: Alisdair Boraston, Garry Taylor, Warren Wakarchuck

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about CBM47, its carbohydrate ligand(s), and how they interact to mediate cell communication.
=== Carbohydrate ligands ===
CBM47 is a fucose specific binding module that is related to ''Anguilla anguilla'' fucolectin. The high affinity ligand for CBM47 has been determined from glycan microarray screening on the CFG microarray[http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_GLYCAN_v3_34_08192004#]to be Fucα1-2Galβ1-4(Fucα1-3)GlcNAc [Lewis y]<ref name="Boraston 2006"/>.

[[File:Lewisy.jpg]]
 

=== Cellular expression of GBP and ligands ===
The CBM47 modules from the ''Streptococcus pneumoniae'' enzyme SpGH98 (or "fucolectin-related protein") are specific to the Lewisy antigen<ref name="Boraston 2006"/>, which is quite rare among all GBPs, and function to target this enzyme to this antigen when present on epithelial cells<ref name="Higgins 2009"/>.
 
=== Biosynthesis of ligands ===
Lewis Y synthesis requires the addition of both α1-2 fucose to the terminal galactose residue and α1-3 fucose to the sub-terminal GlcNAc residue on a type 2 chain. Addition of the α1-2 fucose can be catalyzed by fucosyltransferases FUT1 [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_598&sideMenu=true&pageType=general] and FUT2 [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_599&sideMenu=true&pageType=general], while additon of the α1-3 fucose can be catalyzed by FUT4 [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_601&sideMenu=true&pageType=general] and FUT9 [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_606&sideMenu=true&pageType=general]. In lung adenocarcinomas, the FUT1 and FUT4 enzymes are primarily responsible for Lewis Y synthesis.<ref>Yang, X, Zhang, Z, Jia, S, Liu, T Wang X, and Yan, Q (2007) Overexpression of fucosyltransferase IV in A431 cell line increases cell proliferation. Int. J. Biochem. Cell Biol. 39, 1722–1730</ref>
 

=== Structure ===

CBM47 originates from a multimodular ''S. pneumoniae'' that has an N-terminal, Lewisy degrading catalytic module. Indeed, three CBM47 modules are found in tandem.

[[File:modular.jpg]]

The high resolution X-ray structures of the N-terminal and C-terminal CBM47 modules have been determined and the N-terminal module in complex with the Lewisy tetrasaccharide<ref name="Boraston 2006"/>.

[[File:CBM47.jpg]]

 

=== Biological roles of GBP-ligand interaction ===

The primary role of CBM47, and indeed other CBMs found in carbohydrate-active enzymes, is to direct the entire enzyme to its glycan substrate. However, CBMs found in carbohydrate-active enzymes attached to microbial cell surfaces may also play a role in the adhesion of the bacterium to host glycan-bearing tissues.
 
Recognition and destruction of the Lewisy antigen by CBM47 appears to be a critical process in pneumococcal virulence<ref name="Hava 16"/><ref name="Embry 2007"/>.

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=CBM&maxresults=20 CFG database search results for CBM].

=== Glycan profiling ===

 
=== Glycogene microarray ===
CBM47 is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
Not applicable.
 

=== Glycan array ===
The specificity of several CBMs have been investigated by CFG glycan array analysis (click [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1831 here] for example). Isolated glycans for structural and quantitative binding studies have also been obtained from the CFG.

== Related GBPs ==

There are presently over 55 families of CBMs that are defined on the basis of amino acid sequence similarity; however, the majority of these CBMs families contain members specific for plant cell wall polysaccharides. CFG resources have been instrumental in studying the subset of CBMs that recognize complex glycans. In addition to CBM47 there are a number of CBMs belonging to family 32 and 51 that share the property of binding complex glycans. Though unrelated at the amino acid sequence level CBMs in families 32, 47, and 51 are structurally related and functionally related. It is important to note, however, that the diversity of complex glycan binding among these family members is considerable and only coming to light through glycan array screening. The availability of purfied glycans is facilitating structural and quantitative studies of glycan binding by CBMs in families 32, 47, and 51.

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Alisdair Boraston, Anne Imberty

PA-IIL

2011-10-09T09:11:01Z

Kurt Drickamer: /* Biosynthesis of ligands */

PA-IIL (Pseudomonas lectin II, LecB) is a cytoplasmic lectin produced in ''Pseudomonas aruginosa'' under the control of quorum sensing. It is a virulence factor involved in binding of human tissues such as epithelial lung of cystic fibrosis patients<ref name="Imberty 2004">Imberty, A., Wimmerova, M., Mitchell, E. P. & Gilboa-Garber, N. (2004). Structures of the lectins from Pseudomonas aeruginosa: Insights into molecular basis for host glycan recognition. Microb. Infect. 6, 222-229.</ref>. The role of PA-IIL in pathogenesis has been highlighted, since interfering with PA-IIL binding site reduces the mortality of ''P. aeruginosa'' induced-pneumonia in a murine model<ref name="Chemani 2009">Chemani, C., Imberty, A., de Bentzman, S., Pierre, P., Wimmerová, M., Guery, B. P. & Faure, K. (2009). Role of LecA and LecB lectins in Pseudomonas aeruginosa induced lung injury and effect of carbohydrates ligands. Infect. Immun. 77, 2065-2075.</ref>. The paradigm is unique among glycan-binding proteins (GBPs) in that it contains two cationic ions in the carbohydrate binding site that result in unusual high affinity for the carbohydrate target<ref>Loris, R., Tielker, D., Jaeger, K.-E. & Wyns, L. (2003). Structural basis of carbohydrate recognition by the lectin LecB from Pseudomonas aeruginosa. J. Mol. Biol. 331, 861-870.</ref><ref name="test 1">Mitchell, E., Houles, C., Sudakevitz, D., Wimmerova, M., Gautier, C., Pérez, S., Wu, A. M., Gilboa-Garber, N. & Imberty, A. (2002). Structural basis for oligosaccharide-mediated adhesion of Pseudomonas aeruginosa in the lungs of cystic fibrosis patients. Nature Struct. Biol. 9, 918-921.</ref><ref>Mitchell, E. P., Sabin, C., Šnajdrová, L., Pokorná, M., Perret, S., Gautier, C., Hofr, C., Gilboa-Garber, N., Koča, J., Wimmerová, M. & Imberty, A. (2005). High affinity fucose binding of Pseudomonas aeruginosa lectin PA-IIL: 1.0 Å resolution crystal structure of the complex combined with thermodynamics and computational chemistry approaches. Proteins: Struct. Funct. Bioinfo. 58, 735-748.</ref>. The preferred glycan ligand of PA-IIL is the trisaccharide Lewis a<ref name="test 2">Perret, S., Sabin, C., Dumon, C., Pokorná, M., Gautier, C., Galanina, O., Ilia, S., Bovin, N., Nicaise, M., Desmadril, M., Gilboa-Garber, N., Wimmerova, M., Mitchell, E. P. & Imberty, A. (2005). Structural basis for the interaction between human milk oligosaccharides and the bacterial lectin PA-IIL of Pseudomonas aeruginosa. Biochem. J. 389, 325-332.</ref>. PA-IIL-like lectins have been characterized in other opportunistic bacteria such as ''Ralstonia solanacearum''<ref>Sudakevitz, D., Kostlanova, N., Blatman-Jan, G., Mitchell, E. P., Lerrer, B., Wimmerova, M., Katcof, f. D. J., Imberty, A. & Gilboa-Garber, N. (2004). A new Ralstonia solanacearum high affinity mannose-binding lectin RS-IIL structurally resembling the Pseudomonas aeruginosa fucose-specific lectin PA-IIL. Mol. Microbiol. 52, 691-700.</ref>, ''Chromobacterium violaceum''<ref name="Pokorna 11">Pokorná, M., Cioci, G., Perret, S., Rebuffet, E., Kostlánová, N., Adam, J., Gilboa-Garber, N., Mitchell, E. P., Imberty, A. & Wimmerová, M. (2006). Unusual entropy driven affinity of Chromobacterium violaceum lectin CV-IIL towards fucose and mannose. Biochemistry 45, 7501-7510.</ref>, and ''Burkholderia cenocepacia''<ref>Lameignere, E., Malinovská, L., Sláviková, M., Duchaud, E., Mitchell, E. P., Varrot, A., Šedo, O., Imberty, A. & Wimmerová, M. (2008). Structural basis for mannose recognition by a lectin from opportunistic bacteria Burkholderia cenocepacia. Biochem. J. 411, 307-318.</ref><ref>Lameignere, E., Shiao, T. C., Roy, R., Wimmerová, M., Dubreuil, F., Varrot, A. & Imberty, A. (2010). Structural basis of the affinity for oligomannosides and analogs displayed by BC2L-A, a Burkholderia cenocepacia soluble lectin. Glycobiology 20, 87-98.</ref>, albeit with some variations in the fine specificity. Starting from the results obtained with the help of CFG tools, major efforts are devoided in collaboration with carbohydrate chemists in order to design anti-bacterial new glyco-derived compounds that bind to PA-IIL with high affinity<ref>Imberty, A., Chabre, Y. M. & Roy, R. (2008). Glycomimetics and glycodendrimers as high affinity microbial antiadhesins. Chemistry 14, 7490-7499.</ref>.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
CFG Participating Investigators (PIs) have made major contribution to the understanding of the structure/specificity relationship of PA-IIL and PA-IIL-like proteins. These include: Anne Imberty, Remy Loris, Michaela Wimmerova

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about PA-IIL, its carbohydrate ligand(s), and how they interact to mediate cell communication.
=== Carbohydrate ligands ===

PA-IIL is a fucose-specific lectin that also recognises mannose residues. 
The high affinity ligand for PA-IIL has been deduced from glycan microarray screening on the CFG microarray[http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_GLYCAN_v3_221_02142006#] to be Galβ1-4(Fucα1-4)GlcNAc [Lewis a] <ref name="test 1"></ref><ref name="test 2"></ref><ref>Marotte K, Sabin C, Preville C, Moume-Pymbock M, Wimmerova M, Mitchell EP, Imberty A, Roy R. (2008) X-ray Structures and thermodynamics of the interaction of PA-IIL from Pseudomonas aeruginosa with disaccharide derivatives. ChemMedChem 10,1328-1338.</ref>

[[File:lewisa.jpg]]

=== Cellular expression of GBP and ligands ===
PA-IIL is produced in ''Pseudomonas aruginosa,'' and binds ligands in human tissues, including epithelial lung.
 
=== Biosynthesis of ligands ===

 

=== Structure ===
PA-IIL is a tetrameric lectin. Each monomer consists of a β-sandwich and contains two calcium ions that interact directly with the carbohydrate ligand. Crystal structures have been determined for PA-IIL alone, and its complex with fucose, with related monosaccharides, and with complex fucosylated oligosaccharides.

[[File:pa2ls.jpg]]
 
Information on crystal structures of PA-IIL and links to PDB are available at PA-IIL page of [http://www.cermav.cnrs.fr/cgi-bin/lectines/menu.cgi?Bacterial%20lectins+2-CA%20b-sandwich+Pseudomonas%20PA-IIL 3D-lectin database]

=== Biological roles of GBP-ligand interaction ===
PA-IIL, a virulence factor that binds human tissues such as epithelial lung of cystic fibrosis patients<ref name="Imberty 2004"/>, has roles in pathogenesis <ref name="Chemani 2009"/>.
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=PA-IIL&maxresults=20 CFG database search results for PA-IIL].

=== Glycan profiling ===

 
=== Glycogene microarray ===
PA-IIL is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
Not applicable.
 

=== Glycan array ===
The specificity of PA-IIl and related proteins was determined through glycan array analysis (click [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_PA_v2_230_02102006 here] and [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_GLYCAN_v3_221_02142006# here]).

== Related GBPs ==
CV-IIL [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=CV-IIL&maxresults=20 (CFG data)], RS-IIL [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=RS-IIL&cat=coreh (CFG data)], BC2L-A, BC2L-B [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BC2L-B&maxresults=20 (CFG data)], BC2L-C [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BC2L-C&maxresults=20 (CFG data)].

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Anne Imberty and Micha Wimmerova

PA-IIL

2011-10-09T09:10:29Z

Kurt Drickamer: /* Biosynthesis of ligands */

PA-IIL (Pseudomonas lectin II, LecB) is a cytoplasmic lectin produced in ''Pseudomonas aruginosa'' under the control of quorum sensing. It is a virulence factor involved in binding of human tissues such as epithelial lung of cystic fibrosis patients<ref name="Imberty 2004">Imberty, A., Wimmerova, M., Mitchell, E. P. & Gilboa-Garber, N. (2004). Structures of the lectins from Pseudomonas aeruginosa: Insights into molecular basis for host glycan recognition. Microb. Infect. 6, 222-229.</ref>. The role of PA-IIL in pathogenesis has been highlighted, since interfering with PA-IIL binding site reduces the mortality of ''P. aeruginosa'' induced-pneumonia in a murine model<ref name="Chemani 2009">Chemani, C., Imberty, A., de Bentzman, S., Pierre, P., Wimmerová, M., Guery, B. P. & Faure, K. (2009). Role of LecA and LecB lectins in Pseudomonas aeruginosa induced lung injury and effect of carbohydrates ligands. Infect. Immun. 77, 2065-2075.</ref>. The paradigm is unique among glycan-binding proteins (GBPs) in that it contains two cationic ions in the carbohydrate binding site that result in unusual high affinity for the carbohydrate target<ref>Loris, R., Tielker, D., Jaeger, K.-E. & Wyns, L. (2003). Structural basis of carbohydrate recognition by the lectin LecB from Pseudomonas aeruginosa. J. Mol. Biol. 331, 861-870.</ref><ref name="test 1">Mitchell, E., Houles, C., Sudakevitz, D., Wimmerova, M., Gautier, C., Pérez, S., Wu, A. M., Gilboa-Garber, N. & Imberty, A. (2002). Structural basis for oligosaccharide-mediated adhesion of Pseudomonas aeruginosa in the lungs of cystic fibrosis patients. Nature Struct. Biol. 9, 918-921.</ref><ref>Mitchell, E. P., Sabin, C., Šnajdrová, L., Pokorná, M., Perret, S., Gautier, C., Hofr, C., Gilboa-Garber, N., Koča, J., Wimmerová, M. & Imberty, A. (2005). High affinity fucose binding of Pseudomonas aeruginosa lectin PA-IIL: 1.0 Å resolution crystal structure of the complex combined with thermodynamics and computational chemistry approaches. Proteins: Struct. Funct. Bioinfo. 58, 735-748.</ref>. The preferred glycan ligand of PA-IIL is the trisaccharide Lewis a<ref name="test 2">Perret, S., Sabin, C., Dumon, C., Pokorná, M., Gautier, C., Galanina, O., Ilia, S., Bovin, N., Nicaise, M., Desmadril, M., Gilboa-Garber, N., Wimmerova, M., Mitchell, E. P. & Imberty, A. (2005). Structural basis for the interaction between human milk oligosaccharides and the bacterial lectin PA-IIL of Pseudomonas aeruginosa. Biochem. J. 389, 325-332.</ref>. PA-IIL-like lectins have been characterized in other opportunistic bacteria such as ''Ralstonia solanacearum''<ref>Sudakevitz, D., Kostlanova, N., Blatman-Jan, G., Mitchell, E. P., Lerrer, B., Wimmerova, M., Katcof, f. D. J., Imberty, A. & Gilboa-Garber, N. (2004). A new Ralstonia solanacearum high affinity mannose-binding lectin RS-IIL structurally resembling the Pseudomonas aeruginosa fucose-specific lectin PA-IIL. Mol. Microbiol. 52, 691-700.</ref>, ''Chromobacterium violaceum''<ref name="Pokorna 11">Pokorná, M., Cioci, G., Perret, S., Rebuffet, E., Kostlánová, N., Adam, J., Gilboa-Garber, N., Mitchell, E. P., Imberty, A. & Wimmerová, M. (2006). Unusual entropy driven affinity of Chromobacterium violaceum lectin CV-IIL towards fucose and mannose. Biochemistry 45, 7501-7510.</ref>, and ''Burkholderia cenocepacia''<ref>Lameignere, E., Malinovská, L., Sláviková, M., Duchaud, E., Mitchell, E. P., Varrot, A., Šedo, O., Imberty, A. & Wimmerová, M. (2008). Structural basis for mannose recognition by a lectin from opportunistic bacteria Burkholderia cenocepacia. Biochem. J. 411, 307-318.</ref><ref>Lameignere, E., Shiao, T. C., Roy, R., Wimmerová, M., Dubreuil, F., Varrot, A. & Imberty, A. (2010). Structural basis of the affinity for oligomannosides and analogs displayed by BC2L-A, a Burkholderia cenocepacia soluble lectin. Glycobiology 20, 87-98.</ref>, albeit with some variations in the fine specificity. Starting from the results obtained with the help of CFG tools, major efforts are devoided in collaboration with carbohydrate chemists in order to design anti-bacterial new glyco-derived compounds that bind to PA-IIL with high affinity<ref>Imberty, A., Chabre, Y. M. & Roy, R. (2008). Glycomimetics and glycodendrimers as high affinity microbial antiadhesins. Chemistry 14, 7490-7499.</ref>.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
CFG Participating Investigators (PIs) have made major contribution to the understanding of the structure/specificity relationship of PA-IIL and PA-IIL-like proteins. These include: Anne Imberty, Remy Loris, Michaela Wimmerova

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about PA-IIL, its carbohydrate ligand(s), and how they interact to mediate cell communication.
=== Carbohydrate ligands ===

PA-IIL is a fucose-specific lectin that also recognises mannose residues. 
The high affinity ligand for PA-IIL has been deduced from glycan microarray screening on the CFG microarray[http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_GLYCAN_v3_221_02142006#] to be Galβ1-4(Fucα1-4)GlcNAc [Lewis a] <ref name="test 1"></ref><ref name="test 2"></ref><ref>Marotte K, Sabin C, Preville C, Moume-Pymbock M, Wimmerova M, Mitchell EP, Imberty A, Roy R. (2008) X-ray Structures and thermodynamics of the interaction of PA-IIL from Pseudomonas aeruginosa with disaccharide derivatives. ChemMedChem 10,1328-1338.</ref>

[[File:lewisa.jpg]]

=== Cellular expression of GBP and ligands ===
PA-IIL is produced in ''Pseudomonas aruginosa,'' and binds ligands in human tissues, including epithelial lung.
 
=== Biosynthesis of ligands ===
Lewis Y synthesis requires the addition of both α1-2 fucose to the terminal galactose residue and α1-3 fucose to the sub-terminal GlcNAc residue on a type 2 chain. Addition of the α1-2 fucose can be catalyzed by fucosyltransferases FUT1 [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_598&sideMenu=true&pageType=general] and FUT2 [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_599&sideMenu=true&pageType=general], while additon of the α1-3 fucose can be catalyzed by FUT4 [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_601&sideMenu=true&pageType=general] and FUT9 [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_606&sideMenu=true&pageType=general]. In lung adenocarcinomas, the FUT1 and FUT4 enzymes are primarily responsible for Lewis Y synthesis.<ref>Yang, X, Zhang, Z, Jia, S, Liu, T Wang X, and Yan, Q (2007) Overexpression of fucosyltransferase IV in A431 cell line increases cell proliferation. Int. J. Biochem. Cell Biol. 39, 1722–1730</ref>
 

=== Structure ===
PA-IIL is a tetrameric lectin. Each monomer consists of a β-sandwich and contains two calcium ions that interact directly with the carbohydrate ligand. Crystal structures have been determined for PA-IIL alone, and its complex with fucose, with related monosaccharides, and with complex fucosylated oligosaccharides.

[[File:pa2ls.jpg]]
 
Information on crystal structures of PA-IIL and links to PDB are available at PA-IIL page of [http://www.cermav.cnrs.fr/cgi-bin/lectines/menu.cgi?Bacterial%20lectins+2-CA%20b-sandwich+Pseudomonas%20PA-IIL 3D-lectin database]

=== Biological roles of GBP-ligand interaction ===
PA-IIL, a virulence factor that binds human tissues such as epithelial lung of cystic fibrosis patients<ref name="Imberty 2004"/>, has roles in pathogenesis <ref name="Chemani 2009"/>.
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=PA-IIL&maxresults=20 CFG database search results for PA-IIL].

=== Glycan profiling ===

 
=== Glycogene microarray ===
PA-IIL is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
Not applicable.
 

=== Glycan array ===
The specificity of PA-IIl and related proteins was determined through glycan array analysis (click [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_PA_v2_230_02102006 here] and [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_GLYCAN_v3_221_02142006# here]).

== Related GBPs ==
CV-IIL [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=CV-IIL&maxresults=20 (CFG data)], RS-IIL [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=RS-IIL&cat=coreh (CFG data)], BC2L-A, BC2L-B [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BC2L-B&maxresults=20 (CFG data)], BC2L-C [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BC2L-C&maxresults=20 (CFG data)].

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Anne Imberty and Micha Wimmerova

Candida glabrata EPA7

2011-10-02T18:10:40Z

Kurt Drickamer: /* Biosynthesis of ligands */

'''Fungal adhesins with lectin properties''' 
Cell adhesion proteins on fungal cell surfaces mediate interactions both with other cells of the same type and with the external environment<ref>Douglas, L.M., Li, L., Yang, Y. and Dranginis, A.M. 2007. Expression and characterization of the flocculin Flo11/Muc1, a Saccharomyces cerevisiae mannoprotein with homotypic properties of adhesion. Eukaryot Cell, 6, 2214-2221.</ref><ref>Dranginis, A.M., Rauceo, J.M., Coronado, J.E. and Lipke, P.N. 2007. A biochemical guide to yeast adhesins: glycoproteins for social and antisocial occasions. Microbiol Mol Biol Rev, 71, 282-294.</ref>. These interactions impact critical processes including mating, pathogenesis, and biofilm formation. Fungal adhesins are typically GPI-anchored proteins that have been covalently linked to the cell wall, such that their N-terminal ligand binding domains extend from the cell surface. They frequently occur as families of related proteins<ref>Tronchin, G., Pihet, M., Lopes-Bezerra, L.M. and Bouchara, J.P. 2008. Adherence mechanisms in human pathogenic fungi. Med Mycol, 46, 749-772. </ref>. Members of two such groups, the flocculation/agglutination genes of the model yeast ''Saccharomyces cerevisiae''<ref>Kobayashi, O., Hayashi, N., Kuroki, R. and Sone, H. 1998. Region of FLO1 proteins responsible for sugar recognition. J Bacteriol, 180, 6503-6510.</ref> and the related EPA genes<ref>Kaur, R., Domergue, R., Zupancic, M.L. and Cormack, B.P. 2005. A yeast by any other name: Candida glabrata and its interaction with the host. Curr Opin Microbiol, 8, 378-384.</ref> of the pathogenic fungus ''Candida glabrata'', are lectins. Several of the 23 identified EPA genes have been functionally shown to mediate binding of ''C. glabrata'' to host cells<ref name="Castano 2005">Castano, I., Pan, S.J., Zupancic, M., Hennequin, C., Dujon, B. and Cormack, B.P. 2005. Telomere length control and transcriptional regulation of subtelomeric adhesins in Candida glabrata. Mol Microbiol, 55, 1246-1258.</ref><ref name="Domergue 2005">Domergue, R., Castano, I., de las Penas, A., Zupancic, M., Lockatell, V., Hebel, J.R. et al. 2005. Nicotinic acid limiation regulates silencing of Candida albicans adhesins during UTI. Science, 308, 866-870.</ref>, an essential step in infection and virulence. Defining the specificity of these proteins and their biological roles will elucidate the interactions between host and pathogen, and potentially indicate ways in which to inhibit them for the benefit of the host.

'''''Candida glabrata'' EPA7''' 
The EPA family was chosen as a paradigm because of its relevance to a fungal pathogen that affects human health that can be studied in mouse models of infection. EPA7 was chosen to represent this group because it has been demonstrated to function as an adhesin<ref name="Castano 2005"/> and is one of the EPA proteins that has been studied in the most detail. The N-terminal binding domain of this protein, expressed on the surface of S''. cerevisiae'', has been analyzed on the CFG glycan array. These studies demonstrated EPA7 binding specificity for β1,3- and β1,4-linked galactosides
<ref name=" Zupancic, M.L., 2008">
Zupancic, M.L., Frieman, M., Smith, D., Alvarez, R.A., Cummings, R.D. and Cormack, B.P. 2008. Glycan microarray analysis of Candida glabrata adhesin ligand specificity. Mol Microbiol, 58, 547-559.</ref><ref>de Groot, P.W.J. and Klis, F.M. 2008. The conserved PA14 domain of cell wall-associated fungal adhesins governs their glycan-binding specificity. Mol Microbiol, 68, 535-537. </ref>. This work represents a significant step forward in the area of lectin-like fungal adhesins; in general the specificity of these important proteins remains unexplored.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
* CFG Participating Investigators (PIs) who have contributed to studies of this paradigmatic protein include: Brendan Cormack, Rick Cummings
* PIs using CFG resources to study related ''S. cerevisiae'' proteins include: Lars-Oliver Essen (several flocculins), Peter Lipke (alpha agglutinin and ''Candida albicans'' Als adhesins)

== Progress toward understanding this GBP paradigm ==

=== Carbohydrate ligands ===

Carbohydrate ligands of Epa7 have been examined by glycan array analysis in work from the Cormack group <ref name=" Zupancic, M.L., 2008"></ref>and found to bind almost exclusively to non-reducing terminal β1-4 or β1-3-linked galactose residues. The Epa1 family member has similar specificity while Epa6 binds to most ligands with terminal galactose residues. The related ''S. cerevisiae'' flocculins bind α-mannose or α-glucose residues.

=== Cellular expression of GBP and ligands ===

EPA7 is expressed by the pathogenic fungus ''Candida glabrata''. The EPA gene family is subject to an interesting mechanism of regulation mediated by telomeric silencing. This silencing is relieved in low niacin, leading to increased protein expression. Because urine provides a low niacin growth environment, these adhesins are upregulated in precisely the niche where ''C. glabrata'' must adhere to cause urinary tract infections. 
Consistent with the site of ''C. glabrata'' infection, Epa6 and Epa7 mediate binding to uroepithelial cells in vitro <ref name="Castano 2005"></ref><ref name="Domergue 2005">Domergue, R., Castano, I., de las Penas, A., Zupancic, M., Lockatell, V., Hebel, J.R. et al. 2005. Nicotinic acid limiation regulates silencing of Candida albicans adhesins during UTI. Science, 308, 866-870.</ref>. It has also been noted <ref name=" Zupancic, M.L., 2008"></ref> that "Epa1, Epa6, and Epa7 recognize the T antigen Gal-β1-3GalNAc-α-R, one of the major mucin-type O-glycans found in the colonic epithelium", another site colonized by ''C. glabrata''. 

=== Biosynthesis of ligands ===
On mucins, the Tn (GalNAcα1-Thr/Ser) target ligand for EPA7 is generated by the action of a family of polypeptide O-GalNAc transferases. Transferases T1, T2, T3 and T4 have been suggested to be particularly important in mucin glycosylation.
 

=== Structure ===

Epa proteins are C-type lectins, but no detailed structural information for these proteins is yet available.

=== Biological roles of GBP-ligand interaction ===

Epa7 and other Epa family members, as summarized above, participate in adhesion of the pathogenic yeast ''Candida glabrata'' cells to host cells, leading to infection. Related proteins participate in cell:cell interactions between yeast that can be important for critical processes such as mating or biofilm formation.

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=EPA7&maxresults=20 CFG database search results for "EPA7"].

=== Glycan profiling ===

Glycan profiling of host cell glycans has not been used in connection with this paradigm.

=== Glycogene microarray ===
Mammalian glycogene profiling has not been performed for this paradigm of a fungal protein. Although yeast binding to mammalian cells could conceivably trigger changes in glycogene expression, the critical issue for this adhesin is which glycans are present on the mammalian cell surface upon initial contact. These structures will mediate the cell:cell interactions that are important for establishment of infection.

=== Knockout mouse lines ===

CFG knockout mouse lines have not been used for studies pertaining to this paradigm. Examining ''C. glabrata'' infection using wild type and ''epa'' mutant strains in mice with defects in terminal galactosylation could potentially be of interest.

=== Glycan array ===
The specificity of Epa7 and related proteins was determined through CFG glycan array analysis<ref name=" Zupancic, M.L., 2008"></ref> (click [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1056 here] to see results). To see glycan array results for other EPA family members, click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=EPA&cat=coreh here]. Flocculins from ''S. cerevisiae'' have also been examined by CFG glycan array analysis (click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=flocculin&cat=coreh here]), and glycan array studies of flocculins from ''P. Pastoris'' and of additional ''Candida'' Epa domains have been approved.

== Related GBPs ==
* 22 additional EPA family members in ''C. glabrata''
* Related proteins in ''S. cerevisiae''
* EPA7-like glycan-binding domain also occurs in predicted proteins of ''Ashbya gossypii'' and ''Kluyveromyces lactis''.
(Click here for [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=EPA&maxresults=20 CFG data] on EPA family members)

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Richard Cummings, Tamara Doering, Peter Lipke

Botulinum toxin serotype A (BoNT/A)

2011-09-30T15:08:44Z

Kurt Drickamer: /* Cellular expression of GBP and ligands */

'''The clostridial neurotoxins''' are the most lethal protein toxins for humans and recently have been utilized as therapeutic agents to treat numerous human neurological inflictions. The Botulinum neurotoxins produced by ''Clostridium botulinum'' and Tetanus toxin produced by ''C. tetani'' are members of the family of clostridial neurotoxins. The clostridial neurotoxins are di-chain toxins with the N-terminal catalytic domains (Light Chain, LC) possessing metalloprotease activity that is disulfide linked to the C-terminal
domain (Heavy Chain, HC). The neurological toxicity and therapeutic utility of the clostridial neurotoxins is due to the HC’s tropism for neuronal receptors and the LC’s cleavage of neuron-specific target proteins, termed SNARE proteins. SNARE proteins are responsible for the fusion of neurotransmitter vesicles with the plasma membrane. There are seven serotypes of the BoNTs that share primary and ternary structure-function properties. Each BoNT serotype utilizes dual receptors for entry into neurons and each cleaves a specific SNARE protein or a unique site on a specific SNARE protein.

'''The Botulinum neurotoxins''' elicit flaccid paralysis, while tetanus toxin elicits spastic paralysis. The differential toxicity is due to the unique trafficking of these toxins in motor neurons. Botulinum neurotoxin HC binds to dual host receptors on the surface of motor neurons to deliver the BoNT to acidified vesicles where the LC is translocated into the cytoplasm of the neuron. Upon entry into the cytoplasm, LC cleaves a SNARE protein which inhibits fusion of neurotransmitter vesicles to the plasma membrane, inhibiting the release of neurotransmitter molecules. In contrast, TeNT HC binds to dual host receptors on the surface of motor neurons to deliver the TeNT to neutral vesicles for retrograde trafficking to the central nervous system. Following this transcytosis, Tetanus toxin binds dual receptors on inhibitory neurons to deliver TeNT to acidified endosomes where the LC is translocated into the cytoplasm of the neuron. TeNT LC cleaves the SNARE proteins, VAMP-2, which inhibits the release of neurotransmitters from inhibitory motor neurons. The inability to release neurotransmitter from inhibitory motor neurons yields spastic paralysis.

'''Botulinum toxin serotype A (BoNT/A)''' was chosen as the paradigm for the clostridial neurotoxins, since the dual host receptors for BoNT/A have been determined and the basis for recognizing cleavage of the SNARES substrate SNAP25 has been characterized. In addition, BoNT/A is the most common serotype used in clinical therapies. It is anticipated that understanding BoNT/A action will provide new information relevant to the entire family of clostridial neurotoxins. These studies will enhance the understanding of the unique
properties of each BoNT serotype and Tetanus toxin to extend their utility in human inflictions. The CFG has been used to facilitate the characterization of the ganglioside binding pocket of these neurotoxins. Prior studies utilized low throughput analyses that provided limited insight into interactions between these neurotoxins and gangliosides, and but high throughput analysis of the CFG core provided a better understanding of the biochemical and structural interactions of the neurotoxins with glycans. For example, array analysis showed that the dual receptors for Tetanus toxin recognized unique components of gangliosides.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
CFG Participating Investigators (PIs) contributing to the understanding of BoNT/A include: Joseph Barbieri, Edwin Chapman, Minoru Fukuda, Raymond Stevens, Willie Vann

== Progress toward understanding this GBP paradigm ==

=== Carbohydrate ligands ===
Botulinum neurotoxins bind to two co-receptors on neuronal cell surfaces: common glycolipid receptors and different protein receptors that target them to specific cell types. The common ganglioside co-receptor is GT1b<ref>Yowler BC, Schengrund CL. Botulinum neurotoxin A changes conformation upon binding to ganglioside GT1b. "Biochemistry" 43, 9725-9731 (2004) </ref>.<ref> Stenmark. P, Dupuy1, J, Imamura, A, Kiso, M, and Stevens, RC. Crystal Structure of Botulinum Neurotoxin Type A in Complex with the Cell Surface Co-Receptor GT1b—Insight into the Toxin–Neuron Interaction “PLOS Pathogens” 4, e1000129 (2008) </ref>
 

=== Cellular expression of GBP and ligands ===
Botulinum toxins are produced by ''Clostridium botulinum'' Their target glycolipid and protein receptors are found on the surface of motorneurons.
 

=== Biosynthesis of ligands ===

 
=== Structure ===
The crystal structure of BoNT/A has been solved both alone and bound to its ganglioside co-receptor (see [http://pathema.jcvi.org/cgi-bin/Clostridium/shared/HtmlPage.cgi?page=bont_structures#typeA entry in Panthema] NIAID Bioinformatics Resource Center).
 

=== Biological roles of GBP-ligand interaction ===
Botulinum toxins cause neurotoxicity by cleaving SNARE proteins, which normally allow neurotransmitter-containing vesicles to fuse with the neuronal plasma membrane.
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=botulinum&maxresults=20 CFG database search results for botulinum].

=== Glycan profiling ===

 
=== Glycogene microarray ===
BoNT/A is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
Not applicable.
 

=== Glycan array ===
The CFG synthesized ganglioside derivates that have been used in co-crystallization studies with the clostridial neurotoxins. The CFG glycan array was used to identify the ganglioside binding specificity to the clostridial neurotoxins ([http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_2011 BoNT/C], [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1972 BoNT/D], [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1681 BoNT/F]).

== Related GBPs ==

Botulinum neurotoxins serotypes B-G (CFG data: [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FB&maxresults=20 BoNT/B,] [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FC&maxresults=20 BoNT/C,][http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FD&maxresults=20 BoNT/D,][http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FE&maxresults=20 BoNT/E,][http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=Botulinum+AND+neurotoxin+AND+F&maxresults=20 BoNT/F,][http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FG&maxresults=20 BoNT/G)], Tetanus toxin [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=tetanus+AND+toxin&maxresults=20 (CFG data)]

== References ==
<references/>
* C. Chen, Z. Fu, J-J. P. Kim, J.T. Barbieri, and M. R. Baldwin. 2009. Gangliosides as High Affinity Receptors for Tetanus Neurotoxin. J Biol Chem. 284: 26569-77. PMC2785345
* M. Dong, W. H. Tepp, H. Liu, E. A. Johnson, and E. R. Chapman. 2007. Mechanism of botulinum neurotoxin B and G entry into hippocampal neurons. J. Cell Biol. 179: 1511-1522. PMC2373501

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Joseph Barbieri, James Paton

Botulinum toxin serotype A (BoNT/A)

2011-09-30T15:06:04Z

Kurt Drickamer: /* Structure */

'''The clostridial neurotoxins''' are the most lethal protein toxins for humans and recently have been utilized as therapeutic agents to treat numerous human neurological inflictions. The Botulinum neurotoxins produced by ''Clostridium botulinum'' and Tetanus toxin produced by ''C. tetani'' are members of the family of clostridial neurotoxins. The clostridial neurotoxins are di-chain toxins with the N-terminal catalytic domains (Light Chain, LC) possessing metalloprotease activity that is disulfide linked to the C-terminal
domain (Heavy Chain, HC). The neurological toxicity and therapeutic utility of the clostridial neurotoxins is due to the HC’s tropism for neuronal receptors and the LC’s cleavage of neuron-specific target proteins, termed SNARE proteins. SNARE proteins are responsible for the fusion of neurotransmitter vesicles with the plasma membrane. There are seven serotypes of the BoNTs that share primary and ternary structure-function properties. Each BoNT serotype utilizes dual receptors for entry into neurons and each cleaves a specific SNARE protein or a unique site on a specific SNARE protein.

'''The Botulinum neurotoxins''' elicit flaccid paralysis, while tetanus toxin elicits spastic paralysis. The differential toxicity is due to the unique trafficking of these toxins in motor neurons. Botulinum neurotoxin HC binds to dual host receptors on the surface of motor neurons to deliver the BoNT to acidified vesicles where the LC is translocated into the cytoplasm of the neuron. Upon entry into the cytoplasm, LC cleaves a SNARE protein which inhibits fusion of neurotransmitter vesicles to the plasma membrane, inhibiting the release of neurotransmitter molecules. In contrast, TeNT HC binds to dual host receptors on the surface of motor neurons to deliver the TeNT to neutral vesicles for retrograde trafficking to the central nervous system. Following this transcytosis, Tetanus toxin binds dual receptors on inhibitory neurons to deliver TeNT to acidified endosomes where the LC is translocated into the cytoplasm of the neuron. TeNT LC cleaves the SNARE proteins, VAMP-2, which inhibits the release of neurotransmitters from inhibitory motor neurons. The inability to release neurotransmitter from inhibitory motor neurons yields spastic paralysis.

'''Botulinum toxin serotype A (BoNT/A)''' was chosen as the paradigm for the clostridial neurotoxins, since the dual host receptors for BoNT/A have been determined and the basis for recognizing cleavage of the SNARES substrate SNAP25 has been characterized. In addition, BoNT/A is the most common serotype used in clinical therapies. It is anticipated that understanding BoNT/A action will provide new information relevant to the entire family of clostridial neurotoxins. These studies will enhance the understanding of the unique
properties of each BoNT serotype and Tetanus toxin to extend their utility in human inflictions. The CFG has been used to facilitate the characterization of the ganglioside binding pocket of these neurotoxins. Prior studies utilized low throughput analyses that provided limited insight into interactions between these neurotoxins and gangliosides, and but high throughput analysis of the CFG core provided a better understanding of the biochemical and structural interactions of the neurotoxins with glycans. For example, array analysis showed that the dual receptors for Tetanus toxin recognized unique components of gangliosides.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
CFG Participating Investigators (PIs) contributing to the understanding of BoNT/A include: Joseph Barbieri, Edwin Chapman, Minoru Fukuda, Raymond Stevens, Willie Vann

== Progress toward understanding this GBP paradigm ==

=== Carbohydrate ligands ===
Botulinum neurotoxins bind to two co-receptors on neuronal cell surfaces: common glycolipid receptors and different protein receptors that target them to specific cell types. The common ganglioside co-receptor is GT1b<ref>Yowler BC, Schengrund CL. Botulinum neurotoxin A changes conformation upon binding to ganglioside GT1b. "Biochemistry" 43, 9725-9731 (2004) </ref>.<ref> Stenmark. P, Dupuy1, J, Imamura, A, Kiso, M, and Stevens, RC. Crystal Structure of Botulinum Neurotoxin Type A in Complex with the Cell Surface Co-Receptor GT1b—Insight into the Toxin–Neuron Interaction “PLOS Pathogens” 4, e1000129 (2008) </ref>
 

=== Cellular expression of GBP and ligands ===
Botulinum toxins produced by ''Clostridium botulinum'' bind to dual host receptors on the surface of motorneurons.
 
=== Biosynthesis of ligands ===

 
=== Structure ===
The crystal structure of BoNT/A has been solved both alone and bound to its ganglioside co-receptor (see [http://pathema.jcvi.org/cgi-bin/Clostridium/shared/HtmlPage.cgi?page=bont_structures#typeA entry in Panthema] NIAID Bioinformatics Resource Center).
 

=== Biological roles of GBP-ligand interaction ===
Botulinum toxins cause neurotoxicity by cleaving SNARE proteins, which normally allow neurotransmitter-containing vesicles to fuse with the neuronal plasma membrane.
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=botulinum&maxresults=20 CFG database search results for botulinum].

=== Glycan profiling ===

 
=== Glycogene microarray ===
BoNT/A is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
Not applicable.
 

=== Glycan array ===
The CFG synthesized ganglioside derivates that have been used in co-crystallization studies with the clostridial neurotoxins. The CFG glycan array was used to identify the ganglioside binding specificity to the clostridial neurotoxins ([http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_2011 BoNT/C], [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1972 BoNT/D], [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1681 BoNT/F]).

== Related GBPs ==

Botulinum neurotoxins serotypes B-G (CFG data: [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FB&maxresults=20 BoNT/B,] [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FC&maxresults=20 BoNT/C,][http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FD&maxresults=20 BoNT/D,][http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FE&maxresults=20 BoNT/E,][http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=Botulinum+AND+neurotoxin+AND+F&maxresults=20 BoNT/F,][http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FG&maxresults=20 BoNT/G)], Tetanus toxin [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=tetanus+AND+toxin&maxresults=20 (CFG data)]

== References ==
<references/>
* C. Chen, Z. Fu, J-J. P. Kim, J.T. Barbieri, and M. R. Baldwin. 2009. Gangliosides as High Affinity Receptors for Tetanus Neurotoxin. J Biol Chem. 284: 26569-77. PMC2785345
* M. Dong, W. H. Tepp, H. Liu, E. A. Johnson, and E. R. Chapman. 2007. Mechanism of botulinum neurotoxin B and G entry into hippocampal neurons. J. Cell Biol. 179: 1511-1522. PMC2373501

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Joseph Barbieri, James Paton

Botulinum toxin serotype A (BoNT/A)

2011-09-30T15:05:18Z

Kurt Drickamer: /* Carbohydrate ligands */

'''The clostridial neurotoxins''' are the most lethal protein toxins for humans and recently have been utilized as therapeutic agents to treat numerous human neurological inflictions. The Botulinum neurotoxins produced by ''Clostridium botulinum'' and Tetanus toxin produced by ''C. tetani'' are members of the family of clostridial neurotoxins. The clostridial neurotoxins are di-chain toxins with the N-terminal catalytic domains (Light Chain, LC) possessing metalloprotease activity that is disulfide linked to the C-terminal
domain (Heavy Chain, HC). The neurological toxicity and therapeutic utility of the clostridial neurotoxins is due to the HC’s tropism for neuronal receptors and the LC’s cleavage of neuron-specific target proteins, termed SNARE proteins. SNARE proteins are responsible for the fusion of neurotransmitter vesicles with the plasma membrane. There are seven serotypes of the BoNTs that share primary and ternary structure-function properties. Each BoNT serotype utilizes dual receptors for entry into neurons and each cleaves a specific SNARE protein or a unique site on a specific SNARE protein.

'''The Botulinum neurotoxins''' elicit flaccid paralysis, while tetanus toxin elicits spastic paralysis. The differential toxicity is due to the unique trafficking of these toxins in motor neurons. Botulinum neurotoxin HC binds to dual host receptors on the surface of motor neurons to deliver the BoNT to acidified vesicles where the LC is translocated into the cytoplasm of the neuron. Upon entry into the cytoplasm, LC cleaves a SNARE protein which inhibits fusion of neurotransmitter vesicles to the plasma membrane, inhibiting the release of neurotransmitter molecules. In contrast, TeNT HC binds to dual host receptors on the surface of motor neurons to deliver the TeNT to neutral vesicles for retrograde trafficking to the central nervous system. Following this transcytosis, Tetanus toxin binds dual receptors on inhibitory neurons to deliver TeNT to acidified endosomes where the LC is translocated into the cytoplasm of the neuron. TeNT LC cleaves the SNARE proteins, VAMP-2, which inhibits the release of neurotransmitters from inhibitory motor neurons. The inability to release neurotransmitter from inhibitory motor neurons yields spastic paralysis.

'''Botulinum toxin serotype A (BoNT/A)''' was chosen as the paradigm for the clostridial neurotoxins, since the dual host receptors for BoNT/A have been determined and the basis for recognizing cleavage of the SNARES substrate SNAP25 has been characterized. In addition, BoNT/A is the most common serotype used in clinical therapies. It is anticipated that understanding BoNT/A action will provide new information relevant to the entire family of clostridial neurotoxins. These studies will enhance the understanding of the unique
properties of each BoNT serotype and Tetanus toxin to extend their utility in human inflictions. The CFG has been used to facilitate the characterization of the ganglioside binding pocket of these neurotoxins. Prior studies utilized low throughput analyses that provided limited insight into interactions between these neurotoxins and gangliosides, and but high throughput analysis of the CFG core provided a better understanding of the biochemical and structural interactions of the neurotoxins with glycans. For example, array analysis showed that the dual receptors for Tetanus toxin recognized unique components of gangliosides.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
CFG Participating Investigators (PIs) contributing to the understanding of BoNT/A include: Joseph Barbieri, Edwin Chapman, Minoru Fukuda, Raymond Stevens, Willie Vann

== Progress toward understanding this GBP paradigm ==

=== Carbohydrate ligands ===
Botulinum neurotoxins bind to two co-receptors on neuronal cell surfaces: common glycolipid receptors and different protein receptors that target them to specific cell types. The common ganglioside co-receptor is GT1b<ref>Yowler BC, Schengrund CL. Botulinum neurotoxin A changes conformation upon binding to ganglioside GT1b. "Biochemistry" 43, 9725-9731 (2004) </ref>.<ref> Stenmark. P, Dupuy1, J, Imamura, A, Kiso, M, and Stevens, RC. Crystal Structure of Botulinum Neurotoxin Type A in Complex with the Cell Surface Co-Receptor GT1b—Insight into the Toxin–Neuron Interaction “PLOS Pathogens” 4, e1000129 (2008) </ref>
 

=== Cellular expression of GBP and ligands ===
Botulinum toxins produced by ''Clostridium botulinum'' bind to dual host receptors on the surface of motorneurons.
 
=== Biosynthesis of ligands ===

 
=== Structure ===
The crystal structure of BoNT/A has been solved both alone and bound to other molecules (see [http://pathema.jcvi.org/cgi-bin/Clostridium/shared/HtmlPage.cgi?page=bont_structures#typeA entry in Panthema] NIAID Bioinformatics Resource Center).
 

=== Biological roles of GBP-ligand interaction ===
Botulinum toxins cause neurotoxicity by cleaving SNARE proteins, which normally allow neurotransmitter-containing vesicles to fuse with the neuronal plasma membrane.
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=botulinum&maxresults=20 CFG database search results for botulinum].

=== Glycan profiling ===

 
=== Glycogene microarray ===
BoNT/A is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
Not applicable.
 

=== Glycan array ===
The CFG synthesized ganglioside derivates that have been used in co-crystallization studies with the clostridial neurotoxins. The CFG glycan array was used to identify the ganglioside binding specificity to the clostridial neurotoxins ([http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_2011 BoNT/C], [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1972 BoNT/D], [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1681 BoNT/F]).

== Related GBPs ==

Botulinum neurotoxins serotypes B-G (CFG data: [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FB&maxresults=20 BoNT/B,] [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FC&maxresults=20 BoNT/C,][http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FD&maxresults=20 BoNT/D,][http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FE&maxresults=20 BoNT/E,][http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=Botulinum+AND+neurotoxin+AND+F&maxresults=20 BoNT/F,][http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FG&maxresults=20 BoNT/G)], Tetanus toxin [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=tetanus+AND+toxin&maxresults=20 (CFG data)]

== References ==
<references/>
* C. Chen, Z. Fu, J-J. P. Kim, J.T. Barbieri, and M. R. Baldwin. 2009. Gangliosides as High Affinity Receptors for Tetanus Neurotoxin. J Biol Chem. 284: 26569-77. PMC2785345
* M. Dong, W. H. Tepp, H. Liu, E. A. Johnson, and E. R. Chapman. 2007. Mechanism of botulinum neurotoxin B and G entry into hippocampal neurons. J. Cell Biol. 179: 1511-1522. PMC2373501

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Joseph Barbieri, James Paton

Botulinum toxin serotype A (BoNT/A)

2011-09-30T15:02:50Z

Kurt Drickamer: /* Carbohydrate ligands */

'''The clostridial neurotoxins''' are the most lethal protein toxins for humans and recently have been utilized as therapeutic agents to treat numerous human neurological inflictions. The Botulinum neurotoxins produced by ''Clostridium botulinum'' and Tetanus toxin produced by ''C. tetani'' are members of the family of clostridial neurotoxins. The clostridial neurotoxins are di-chain toxins with the N-terminal catalytic domains (Light Chain, LC) possessing metalloprotease activity that is disulfide linked to the C-terminal
domain (Heavy Chain, HC). The neurological toxicity and therapeutic utility of the clostridial neurotoxins is due to the HC’s tropism for neuronal receptors and the LC’s cleavage of neuron-specific target proteins, termed SNARE proteins. SNARE proteins are responsible for the fusion of neurotransmitter vesicles with the plasma membrane. There are seven serotypes of the BoNTs that share primary and ternary structure-function properties. Each BoNT serotype utilizes dual receptors for entry into neurons and each cleaves a specific SNARE protein or a unique site on a specific SNARE protein.

'''The Botulinum neurotoxins''' elicit flaccid paralysis, while tetanus toxin elicits spastic paralysis. The differential toxicity is due to the unique trafficking of these toxins in motor neurons. Botulinum neurotoxin HC binds to dual host receptors on the surface of motor neurons to deliver the BoNT to acidified vesicles where the LC is translocated into the cytoplasm of the neuron. Upon entry into the cytoplasm, LC cleaves a SNARE protein which inhibits fusion of neurotransmitter vesicles to the plasma membrane, inhibiting the release of neurotransmitter molecules. In contrast, TeNT HC binds to dual host receptors on the surface of motor neurons to deliver the TeNT to neutral vesicles for retrograde trafficking to the central nervous system. Following this transcytosis, Tetanus toxin binds dual receptors on inhibitory neurons to deliver TeNT to acidified endosomes where the LC is translocated into the cytoplasm of the neuron. TeNT LC cleaves the SNARE proteins, VAMP-2, which inhibits the release of neurotransmitters from inhibitory motor neurons. The inability to release neurotransmitter from inhibitory motor neurons yields spastic paralysis.

'''Botulinum toxin serotype A (BoNT/A)''' was chosen as the paradigm for the clostridial neurotoxins, since the dual host receptors for BoNT/A have been determined and the basis for recognizing cleavage of the SNARES substrate SNAP25 has been characterized. In addition, BoNT/A is the most common serotype used in clinical therapies. It is anticipated that understanding BoNT/A action will provide new information relevant to the entire family of clostridial neurotoxins. These studies will enhance the understanding of the unique
properties of each BoNT serotype and Tetanus toxin to extend their utility in human inflictions. The CFG has been used to facilitate the characterization of the ganglioside binding pocket of these neurotoxins. Prior studies utilized low throughput analyses that provided limited insight into interactions between these neurotoxins and gangliosides, and but high throughput analysis of the CFG core provided a better understanding of the biochemical and structural interactions of the neurotoxins with glycans. For example, array analysis showed that the dual receptors for Tetanus toxin recognized unique components of gangliosides.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
CFG Participating Investigators (PIs) contributing to the understanding of BoNT/A include: Joseph Barbieri, Edwin Chapman, Minoru Fukuda, Raymond Stevens, Willie Vann

== Progress toward understanding this GBP paradigm ==

=== Carbohydrate ligands ===
Botulinum neurotoxins bind to two co-receptors on neuronal cell surfaces: common glycolipid receptors and different protein receptors that target them to specific cell types. The common ganglioside co-receptor is GT1b.<ref> Stenmark. P, Dupuy1, J, Imamura, A, Kiso, M, and Stevens, RC. Crystal Structure of Botulinum Neurotoxin Type A in Complex with the Cell Surface Co-Receptor GT1b—Insight into the Toxin–Neuron Interaction “PLOS Pathogens” 4, e1000129 (2008) </ref>
 

=== Cellular expression of GBP and ligands ===
Botulinum toxins produced by ''Clostridium botulinum'' bind to dual host receptors on the surface of motorneurons.
 
=== Biosynthesis of ligands ===

 
=== Structure ===
The crystal structure of BoNT/A has been solved both alone and bound to other molecules (see [http://pathema.jcvi.org/cgi-bin/Clostridium/shared/HtmlPage.cgi?page=bont_structures#typeA entry in Panthema] NIAID Bioinformatics Resource Center).
 

=== Biological roles of GBP-ligand interaction ===
Botulinum toxins cause neurotoxicity by cleaving SNARE proteins, which normally allow neurotransmitter-containing vesicles to fuse with the neuronal plasma membrane.
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=botulinum&maxresults=20 CFG database search results for botulinum].

=== Glycan profiling ===

 
=== Glycogene microarray ===
BoNT/A is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
Not applicable.
 

=== Glycan array ===
The CFG synthesized ganglioside derivates that have been used in co-crystallization studies with the clostridial neurotoxins. The CFG glycan array was used to identify the ganglioside binding specificity to the clostridial neurotoxins ([http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_2011 BoNT/C], [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1972 BoNT/D], [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1681 BoNT/F]).

== Related GBPs ==

Botulinum neurotoxins serotypes B-G (CFG data: [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FB&maxresults=20 BoNT/B,] [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FC&maxresults=20 BoNT/C,][http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FD&maxresults=20 BoNT/D,][http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FE&maxresults=20 BoNT/E,][http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=Botulinum+AND+neurotoxin+AND+F&maxresults=20 BoNT/F,][http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FG&maxresults=20 BoNT/G)], Tetanus toxin [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=tetanus+AND+toxin&maxresults=20 (CFG data)]

== References ==
<references/>
* C. Chen, Z. Fu, J-J. P. Kim, J.T. Barbieri, and M. R. Baldwin. 2009. Gangliosides as High Affinity Receptors for Tetanus Neurotoxin. J Biol Chem. 284: 26569-77. PMC2785345
* M. Dong, W. H. Tepp, H. Liu, E. A. Johnson, and E. R. Chapman. 2007. Mechanism of botulinum neurotoxin B and G entry into hippocampal neurons. J. Cell Biol. 179: 1511-1522. PMC2373501

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Joseph Barbieri, James Paton

Botulinum toxin serotype A (BoNT/A)

2011-09-30T14:57:35Z

Kurt Drickamer: /* Carbohydrate ligands */

'''The clostridial neurotoxins''' are the most lethal protein toxins for humans and recently have been utilized as therapeutic agents to treat numerous human neurological inflictions. The Botulinum neurotoxins produced by ''Clostridium botulinum'' and Tetanus toxin produced by ''C. tetani'' are members of the family of clostridial neurotoxins. The clostridial neurotoxins are di-chain toxins with the N-terminal catalytic domains (Light Chain, LC) possessing metalloprotease activity that is disulfide linked to the C-terminal
domain (Heavy Chain, HC). The neurological toxicity and therapeutic utility of the clostridial neurotoxins is due to the HC’s tropism for neuronal receptors and the LC’s cleavage of neuron-specific target proteins, termed SNARE proteins. SNARE proteins are responsible for the fusion of neurotransmitter vesicles with the plasma membrane. There are seven serotypes of the BoNTs that share primary and ternary structure-function properties. Each BoNT serotype utilizes dual receptors for entry into neurons and each cleaves a specific SNARE protein or a unique site on a specific SNARE protein.

'''The Botulinum neurotoxins''' elicit flaccid paralysis, while tetanus toxin elicits spastic paralysis. The differential toxicity is due to the unique trafficking of these toxins in motor neurons. Botulinum neurotoxin HC binds to dual host receptors on the surface of motor neurons to deliver the BoNT to acidified vesicles where the LC is translocated into the cytoplasm of the neuron. Upon entry into the cytoplasm, LC cleaves a SNARE protein which inhibits fusion of neurotransmitter vesicles to the plasma membrane, inhibiting the release of neurotransmitter molecules. In contrast, TeNT HC binds to dual host receptors on the surface of motor neurons to deliver the TeNT to neutral vesicles for retrograde trafficking to the central nervous system. Following this transcytosis, Tetanus toxin binds dual receptors on inhibitory neurons to deliver TeNT to acidified endosomes where the LC is translocated into the cytoplasm of the neuron. TeNT LC cleaves the SNARE proteins, VAMP-2, which inhibits the release of neurotransmitters from inhibitory motor neurons. The inability to release neurotransmitter from inhibitory motor neurons yields spastic paralysis.

'''Botulinum toxin serotype A (BoNT/A)''' was chosen as the paradigm for the clostridial neurotoxins, since the dual host receptors for BoNT/A have been determined and the basis for recognizing cleavage of the SNARES substrate SNAP25 has been characterized. In addition, BoNT/A is the most common serotype used in clinical therapies. It is anticipated that understanding BoNT/A action will provide new information relevant to the entire family of clostridial neurotoxins. These studies will enhance the understanding of the unique
properties of each BoNT serotype and Tetanus toxin to extend their utility in human inflictions. The CFG has been used to facilitate the characterization of the ganglioside binding pocket of these neurotoxins. Prior studies utilized low throughput analyses that provided limited insight into interactions between these neurotoxins and gangliosides, and but high throughput analysis of the CFG core provided a better understanding of the biochemical and structural interactions of the neurotoxins with glycans. For example, array analysis showed that the dual receptors for Tetanus toxin recognized unique components of gangliosides.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
CFG Participating Investigators (PIs) contributing to the understanding of BoNT/A include: Joseph Barbieri, Edwin Chapman, Minoru Fukuda, Raymond Stevens, Willie Vann

== Progress toward understanding this GBP paradigm ==

=== Carbohydrate ligands ===
Botulinum neurotoxins bind to two co-receptors on neuronal cell surfaces: common glycolipid receptors and different protein receptors that target them to specific cell types. The common ganglioside co-receptor is GT1b.
 

=== Cellular expression of GBP and ligands ===
Botulinum toxins produced by ''Clostridium botulinum'' bind to dual host receptors on the surface of motorneurons.
 
=== Biosynthesis of ligands ===

 
=== Structure ===
The crystal structure of BoNT/A has been solved both alone and bound to other molecules (see [http://pathema.jcvi.org/cgi-bin/Clostridium/shared/HtmlPage.cgi?page=bont_structures#typeA entry in Panthema] NIAID Bioinformatics Resource Center).
 

=== Biological roles of GBP-ligand interaction ===
Botulinum toxins cause neurotoxicity by cleaving SNARE proteins, which normally allow neurotransmitter-containing vesicles to fuse with the neuronal plasma membrane.
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=botulinum&maxresults=20 CFG database search results for botulinum].

=== Glycan profiling ===

 
=== Glycogene microarray ===
BoNT/A is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
Not applicable.
 

=== Glycan array ===
The CFG synthesized ganglioside derivates that have been used in co-crystallization studies with the clostridial neurotoxins. The CFG glycan array was used to identify the ganglioside binding specificity to the clostridial neurotoxins ([http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_2011 BoNT/C], [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1972 BoNT/D], [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1681 BoNT/F]).

== Related GBPs ==

Botulinum neurotoxins serotypes B-G (CFG data: [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FB&maxresults=20 BoNT/B,] [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FC&maxresults=20 BoNT/C,][http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FD&maxresults=20 BoNT/D,][http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FE&maxresults=20 BoNT/E,][http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=Botulinum+AND+neurotoxin+AND+F&maxresults=20 BoNT/F,][http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=BoNT%2FG&maxresults=20 BoNT/G)], Tetanus toxin [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=tetanus+AND+toxin&maxresults=20 (CFG data)]

== References ==
<references/>
* C. Chen, Z. Fu, J-J. P. Kim, J.T. Barbieri, and M. R. Baldwin. 2009. Gangliosides as High Affinity Receptors for Tetanus Neurotoxin. J Biol Chem. 284: 26569-77. PMC2785345
* M. Dong, W. H. Tepp, H. Liu, E. A. Johnson, and E. R. Chapman. 2007. Mechanism of botulinum neurotoxin B and G entry into hippocampal neurons. J. Cell Biol. 179: 1511-1522. PMC2373501

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Joseph Barbieri, James Paton

F17G/GafD

2011-04-16T09:36:22Z

Kurt Drickamer: /* Structure */

The F17-G (GafD) adhesin at the tip of flexible F17 fimbriae of enterotoxigenic ''Escherichia coli'' mediates binding to N-acetyl-β-D-glucosamine-presenting receptors on the microvilli of the intestinal epithelium of ruminants, leading to diarrhea or septicaemia. F17-G belong to two-domain adhesins (TDA)s consisting of a pilin domain and a lectin domain, both having an Ig-fold joined via a short interdomain linker
<ref name=" Buts, L2003">
Buts, L., Bouckaert, J., De Gents, E., Loris, R., Oscarson, S., Lahmann, M., Messens, J., Brosens, E., Wyns, L. & De Greve, H. (2003). The fimbrial adhesin F17-G of enterotoxigenic Escherichia coli has an immunoglobulin-like lectin domain that binds N-acetylglucosamine. Mol. Microb. 49, 705-715.</ref><ref>Merckel, M. C., Tanskanen, J., Edelman, S., Westerlund-Wilkström, B., Korhonen, T. K. & Goldman, A. (2003). The structural basis of receptor-binding by Escherichia coli associaed with diarrhea and septicemia. J. Mol. Biol. 331, 897-905.</ref>. Related adhesins have been characterized in enteropathogenic ''E. coli'' ( FedF on F18 fimbriae<ref>Coddens, A., Diswall, M., Angstrom, J., Breimer, M. E., Goddeeris, B., Cox, E. & Teneberg, S. (2009). Recognition of blood group ABH type 1 determinants by the FedF adhesin of F18-fimbriated Escherichia coli. J Biol Chem 284, 9713-26.</ref> and CfaE on CFA/I pili<ref>Poole, S. T., McVeigh, A. L., Anantha, R. P., Lee, L. H., Akay, Y. M., Pontzer, E. A., Scott, D. A., Bullitt, E. & Savarino, S. J. (2007). Donor strand complementation governs intersubunit interaction of fimbriae of the alternate chaperone pathway. Mol Microbiol 63, 1372-84.</ref>) ) and uropathogenic ones (FimH on type 1 fimbriae<ref>Bouckaert, J., Berglund, J., Schembri, M., De Gents, E., Cools, L., Wuhrer, M., Hung, C.-S., Pinkner, J., Slättegard, R., Savialov, A., Choudhury, D., Langermann, S., Hultgren, S. J., Wyns, L., Klemm, P., Oscarson, S., Knight, S. D. & De Greve, H. (2005). Receptor binding studies disclose a novel class of high-affinity inhibitors of the Escherichia coli FimH adhesin. Mol. Microb. 55, 441-455.</ref> and PapG on P-pili<ref>Dodson, K. W., Pinkner, J. S., Rose, T., Magnusson, G., Hultgren, S. J. & Waksman, G. (2001). Structural basis of the interaction of the pyelonephritic E. coli adhesin to ist human kideny receptor. Cell 105, 733-743.</ref>). Fimbrial adhesins from other organisms, such as CupB6 from ''Pseudomonas aeruginosa'' are also investigated. All share the immunoglobulin-like fold of the two structural components, despite lack of any sequence identity and diversity in carbohydrate specificity and binding site, and the corresponding pili are assembled by the chaperone-usher pathway<ref>De Greve, H., Wyns, L. & Bouckaert, J. (2007). Combining sites of bacterial fimbriae. Curr Opin Struct Biol 17, 506-12.</ref><ref>Sauer, F. G., Barnhart, M., Choudhury, D., Knight, S. D., Waksman, G. & Hultgren, S. J. (2000). Chaperone-assisted pilus assembly and bacterial attachment. Curr Opin Struct Biol 10, 548-56.</ref>. The paradigm is unique among TAD for his specificity toward GlcNAc. The binding site is located laterally and not at the tip of the pili, therefore the long and flexible F17 fimbriae could intrude between the microvilli of the epithelium, with the binding site of the lectin domain interacting laterally with GlcNAc-containing receptors. Five naturally occurring variants, differing in 1-18 amino acids of the adhesion domain have been identified<ref>De Kerpel, M., Van Molle, I., Brys, L., Wyns, L., De Greve, H. & Bouckaert, J. (2006). N-terminal truncation enables crystallization of the receptor-binding domain of the FedF bacterial adhesin. Acta Crystallogr Sect F Struct Biol Cryst Commun 62, 1278-82.</ref>.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
This is an emerging field of investigation and contributions arose from a small number of CFG Participating Investigators (PIs). These include: Esther Bullit, Eric Cox, Anne Imberty, Remy Loris, James Nataro

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about F17G/GafD, its carbohydrate ligand(s), and how they interact to mediate cell communication.
=== Carbohydrate ligands ===

The F17G adhesin is most specific for the disaccharide GlcNAcb1,3Gal that can be recognised as a terminal or internal sequence in bovine glycophorin <ref>Mouricout, M., Milhavet, M., Durié, C., Grange, P. Characterization of glycoprotein glycan receptors for Escherichia coli F17 fimbrial lectin, Microb. Pathog. (1995) 18, 297-306</ref>:
 
[[File:carbSynthe_0691_D000.jpg]]
 
The branched form gives a closely similar fluorescent signal:
 
[[File:carbSynthe_0897_D000.jpg]]
 
The presence of the b1,3 linkage of N-acetyl glucosamine to galactose enhances the affinity for F17G at least 2-fold, compared to the monosaccharide N-acetyl glucosamine, as validated using surface plasmon resonance measurements. Second best binders are the b1,4 and b1,6 galactose linked disaccharides, whereas chitobiose, that is also a characterized inhibitor of F17G-mediated bacterial adhesion, is clearly lagging behind. F17G can thus be ranked under glycan binding proteins that display high selectivity.

=== Cellular expression of GBP and ligands ===

F17G adhesins are expressed on enterotoxigenic E. coli infecting neonatal lambs, calves, and goat kids.
The F17G ligand GlcNAcb1,3Gal occurs universally but mostly internally in the sequence of poly-lactosaminyl glycans and blood group antigens.
These glycan structures are widely expressed on mamalian cell surfaces .

=== Biosynthesis of ligands ===
 
F17-fimbriated E. coli predominantly colonize neonatal animals, but also are a major causal agent (55%) of mastitis in bovines <ref>Lipman, L.J.A., de Nijs A., Gaastra W.. Isolation and identification of fimbriae and toxin production by Escherichia coli strains from cows with clinical mastitis, Vet. Microbiology 47 (1995) p. 1-7 </ref>. Congruent with the glycans recognized by F17G on the printed array versions 2.1 and 4.1, the N-acetyl glucosamine residue of GlcNAcb1,3Gal may be unsubstituted at the early life stage of calves, that are at the same time protected from bacterial infections by glycans secreted in the cow's milk.

=== Structure ===
The F17G adhesin is a two-domain adhesin (TDA) located at the F17 fimbrial tip. The determination of the crystal structure of the F17G lectin domain led to the discovery of the variable immunoglobulin-like structure
as a paradigm for bacterial fimbrial TDAs <ref name=" Buts, L2003">
</ref>. F17G has a shallow groove for carbohydrate recognition on its flank.

 
[[File:F17G_Igfold_v3.jpg‎]]
 

=== Biological roles of GBP-ligand interaction ===

The F17G fimbrial lectin enhances intestinal colonization in the early life of ruminants. The long and flexible F17 fimbriae can penetrate deep between intestinal microvilli, where the fimbrial tip adhesin finds its glycan receptors. The subsequent secretion of heat stable and heat labile toxins can lead to severe diarrhea.

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the CFG database search results for [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=fimbriae&maxresults=20 fimbriae] and [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=pili&maxresults=20 pili].

=== Glycan profiling ===

 
=== Glycogene microarray ===
F17G/GafD is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
Not applicable.
 

=== Glycan array ===
F17G adhesins have been screened for their glycan specificity (click [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_PA_v2_177_11182005 here]). To see all glycan array results for F17G adhesin, click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=F17G&cat=coreh here].

== Related GBPs ==
FedF [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=FedF&maxresults=20 (CFG data)], CfaE [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=CfaE&maxresults=20 (CFG data)], FimH [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=FimH&maxresults=20 (CFG data)], PapG, CupB6 [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=CupB6&maxresults=20 (CFG data)].

The specificity of some of the other fimbrial tip adhesins was determined by CFG glycan array analysis ([http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_2358 ''P. gingivalis'' fimbriae], [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_PA_v2_178_11182005 ''E. coli'' FedF adhesin], [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1106 ''E. coli'' CfaE adhesin from CFA/I pili])

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Alisdair Boraston, Julie Bouckaert, Anne Imberty

File:F17G Igfold v3.jpg

2011-04-16T09:34:51Z

Kurt Drickamer:

Mannose receptor

2011-04-16T09:12:54Z

Kurt Drickamer: /* Related GBPs */

The mannose receptor represents a paradigm for the involvement of C-type lectins in clearance of circulating glycoproteins. The role of glycan-binding receptors as tags for uptake and turnover was one of the first established functions for endogenous sugar-binding proteins and provides a key model for how glycans can modulate communication between cells in a physiological context. While the asialoglycoprotein receptor would be considered the founder member of this group of receptors, the in vivo evidence for its function is less compelling than the results for the mannose receptor, which has well defined roles in clearance of sulfated glycoprotein hormones as well as mannose-bearing glycoproteins released at sites of inflammation<ref name="Taylor 2005">Taylor PR, Gordon S, Martinez-Pomares L (2005) The mannose receptor: linking homeostasis and immunity through sugar recognition. Trends Immunol 26,104-110</ref>.

In addition to the mannose receptor and the asialoglycoprotein receptor, the scavenger receptor C-type lectin may also be involved in clearance of serum glycoproteins. The asialoglycoprotein receptor and the scavenger receptor C-type lectin have different domain organisations and ligand binding specificities compared to the mannose receptor.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
PIs working with the mannose receptor include: Ten Feizi; Reiko Lee; Yuan Lee; Michel Nussenzweig; Maureen Taylor; Kurt Drickamer; Chi-Huey Wong; Bill Weis; Pauline Rudd; Nathalie Scholler
== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about the mannose receptor, its carbohydrate ligand(s), and how they interact to mediate cell communication. Further information can be found in the GBP Molecule Pages for the [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_hum_Ctlect_00127&sideMenu=no human] and [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_mou_Ctlect_181&sideMenu=no mouse] mannose receptor in the CFG database.

 As in the case of the selectins, much of the evidence for functions of the mannose receptor pre-dates the consortium. However, there have been some further developments for this receptor and other members of the group. PIs have generated and characterized knockout mice, defined the sugar-binding specificities, demonstrated clearance in vivo and endocytosis in tissue culture, and performed structural analysis.
 
=== Carbohydrate ligands ===

The multiple domains in the extracellular region of the mannose receptor allow recognition of a diverse range of glycoconjugate ligands<ref name="Taylor 1990">Taylor, ME, Conary, JT, Lennartz, MR, Stahl, PD, Drickamer, K (1990) Primary structure of the mannose receptor contains multiple motifs resembling carbohydrate-recognition domains.J Biol Chem 265,12156-12162</ref>. Several of the eight C-type carbohydrate-recognition domains are involved in Ca2+-dependent recognition of terminal mannose, GlcNAc or fucose residues on the oligosaccharides of endogenous glycoproteins or the surfaces of microorganisms<ref name="Taylor 1992">Taylor, ME., Bezouska, K, Drickamer, K (1992) Contribution to ligand binding by multiple carbohydrate-recognition domains in the macrophage mannose receptor. J Biol Chem 267, 1710-1726</ref><ref name="Mullin 1997">Mullin, NP, Hitchen, PG, Taylor, ME (1997) Mechanism of 2+- and monosaccharide-binding to a C-type carbohydrate-recognition domain of the macrophage mannose receptor. J Biol Chem 272, 5668-5681</ref>, while the R-type carbohydrate-recognition domain binds sulfated GalNAc and sulfated galactose residues<ref name="Fiete 1998">Fiete DJ, Beranek MC, Baenziger JU (1998) A cysteine-rich domain of the "mannose" receptor mediates GalNAc-4-SO4 binding. Proc Natl Acad Sci USA 95, 2089-2093</ref>. Biological ligands for the mannose receptor include lysosomal hydrolases, the pro-collagen peptides of type I and type III collagens and tissue plasminogen activator – proteins that bear high mannose oligosaccharides and are released from cells at sites of inflammation<ref name="Lee 2002">Lee SJ, Evers S, Roeder D, Parlow AF, Risteli J, Risteli L, Lee YC, Feizi T, Langen H, Nussenzweig MC (2002) Mannose receptor-mediated regulation of serum glycoprotein homeostasis. Science 295, 1898-1901</ref>. The main biological ligands recognized by the R-type carbohydrate-recognition domain are the pituitary hormones lutropin and thyrotropin which bear oligosaccharides terminating in GalNAc-4-SO4<ref name="Fiete 1998"/><ref name="Liu 2000">Liu Y, Chirino AJ, Misulovin Z, Leteux C, Feizi T, Nussenzweig MC, Bjorkman PJ. (2000) Crystal structure of the cysteine-rich domain of the mannose receptor complexed with a sulfated carbohydrate ligand. J Exp Med 191, 1105-1116</ref>.The CFG contributed to defining specificity for oligosaccharides through screening of glycan arrays<ref name="Hsu 2009">Hsu TL, Cheng SC, Yang WB, Chin SW, Chen BH, Huang MT, Hsieh SL, Wong CH (2009) Profiling carbohydrate-receptor interaction with recombinant innate immunity receptor-Fc fusion proteins. J Biol Chem 284, 34479-34489</ref>.
 

=== Cellular expression of GBP and ligands ===

The mannose receptor was first identified in the liver on sinusoidal endothelial cells and Kupffer cells<ref name="Schlesinger 1978">Schlesinger P, Doebber TW, Mandell BF, White R, DeSchryver C, Rodman JS, Miller MJ, Stahl P (1978) Plasma clearance of glycoproteins with terminal mannose and GlcNAc by liver non-parenchymal cells. Biochem J 176, 103-109</ref>. The receptor has since been found on most types of tissue macrophages, including those in the placenta and the brain, but not on circulating monocytes<ref name="Taylor 2005"/>. The mannose receptor is also expressed in the retinal pigmented epithelium<ref name="Greaton 2003">Greaton CJ, Lane KB, Shepherd VL, McLaughlin BJ (2003) Transcription of a single mannose receptor gene by macrophage and retinal pigment epithelium. Opthalmic Res 35, 42-47</ref> and on CD1-positive dendritic cells<ref name="Sallusto 1995">Sallusto F, Cella M, Danieli C, Lanzavecchia A (1995) Dendritic cells use macropinocytosis and the mannose receptor to concentrate macromolecules in the major hitocompatibility complex class II compartment: downregulation by cytokines and bacterial products. J Exp Med 182, 389-400</ref>. The CFG contributed to defining expression of the mannose receptor by glycogene microarray analysis<ref name="Cornelli 2006">Comelli, EM, Head, SR, Gilmartin, T, Whisenant, T, Haslam, SM, North SJ, Wong, N-K, Kudo, T, Narimatsu, H, Esko, JD, Drickamer, K, Dell, A, Paulson, JC (2006) A focused microarray approach to functional glycomics: transcriptional regulation of the glycome. Glycobiology 16, 117-131</ref>
 
=== Biosynthesis of ligands ===
Glycans on endogenous glycoprotein ligands 
Two transferases expressed in the pituitary are required to synthesize the terminal GalNAc-4-SO4 residues found on the oligosaccharides of hormones such as lutropin. The protein-specific glycoprotein hormone N-acetylgalactosaminyltransferase (protein-specific β1,4GalNAcT) adds GalNAc<ref name”Mengeling1995”>Mengeling BJ, Manzella SM, and Baenziger JU (1999) A cluster of basic amino acids within an α-helix is essential for α-subunit recognition by the glycoprotein hormone N-acetylgalactosaminyltransferase. Proc. Natl. Acad. Sci. U.S.A. 92, 502–506</ref> which is then sulfated by a GalNAc-4-sulfotransferase (GalNAc-4-ST1).<ref name”Boregowda”>Boregowda RK, Mi Y, Bu H, and Baenziger JU (2005) Differential expression and enzymatic properties of GalNAc-4-sulfotransferase-1 and GalNAc-4-sulfotransferase-2. Glycobiology 15, 1349–1358</ref>
 
High mannose oligosaccharides on released lysosomal enzymes are generated from mannose 6-phosphate-containing oligosaccharides ([http://www.functionalglycomics.org/CFGparadigms/index.php/Cation-dependent_Mannose-6-phosphate_receptor M6PR]) by phosphatase activity.
 
Glycans on micro-organisms 
Biosynthesis mannans on fungi has been well studied in a number of species. For example, in the yeast S. cerevisiae, the KRE2/MNT1 genes encode mannosyltransferases that synthesize both N- and O-linked mannans.<ref name”Lussier1999”>Lussier, M, Sdicu, A-M and Bussey, H (1999) The KTR and MNN1 mannosyltransferase families of Saccharomyces cerevisiae. Biochim. Biophys. Acta 1426, 323-334</ref>
 
The mycobacterial transferases for synthesis of the lipo-arabinomannan (LAM) core and the extended ManLAM structures have been characterized.<ref name”Tam2009”>Tam, P-H and Lowary, TL (2009) Recent advances in mycobacterial cell wall glycan biosynthesis. Cur. Opin Struct. Biol. 13, 618-625</ref>
 

=== Structure ===

[[image:Mannose_receptor.jpg]]

The mannose receptor is a type I transmembrane protein, with a large extracellular domain containing three types of domain. An N-terminal R-type carbohydrate-recognition domain is followed by a fibronectin type II domain and eight C-type carbohydrate-recognition domains<ref name="Taylor 1990"/>. The short cytoplasmic C-terminal domain contains a di-aromatic motif essential for rapid internalization and endosomal sorting<ref name="Schweizer 2000">Schweizer A, Stahl PD, Rohrer J (2000) A di-aromatic motif in the cytosolic tail of the mannose receptor mediates endosomal sorting. J Biol Chem 275, 29694-29700</ref>. The structures of two portions of the extracellular domain of the mannose receptor have been determined. The structure of CRD-4 that has been determined represents the conformation when the receptor relases ligand under endosomal conditions ([http://www.rcsb.org/pdb/explore/explore.do?structureId=1EGG CRD-4]). The structure of the R-type CRD has been determined with bound SO4-GalNAc as well as with other sulfated ligands ([http://www.rcsb.org/pdb/explore/explore.do?structureId=1DQO R-type CRD with SO4-GalNAc]). 

Three other endocytic receptors, DEC-205, Endo-180 and the phospholipase A2 receptor, share the same domain organization as the mannose receptor<ref name="Taylor 1997">Taylor, ME (1997) Evolution of a family of receptors containing multiple C-type carbohydrate-recognition domains. Glycobiology 7, v-viii</ref>. Of these, only Endo-180 has been shown to bind carbohydrate ligands.
 

=== Biological roles of GBP-ligand interaction ===

The mannose receptor mediates endocytosis of glycoproteins. Ligand-receptor complexes are internalized via clathrin-coated pits into early endosomes where the ligands are released and targeted to the lysosome for degradation<ref name="Schweizer 2000"/>. The mannose receptor acts to regulate serum levels of proteins such as lysosomal enzymes that are released from cells during inflammation<ref name="Lee 2002"/>. The mannose receptor also regulates levels of pituitary hormones such as lutropin and thyrotropin that must be removed from serum once they have acted on their target cells<ref name="Shapiro 2002">Mi Y, Shapiro SD, Baenziger JU (2002) Regulation of lutropin circulatory half-life by the mannose/N-acetylgalactosamine-4-SO4 receptor is critical for implantation in vivo. J Clin Invest 109, 269-276</ref>. The mannose receptor can also bind and mediate internalization of a wide variety of pathogenic micro-organisms including HIV, the fungi Candida albicans and Aspergillus fumigatus, parasites such as Leishmania donovani and bacteria including Pneumocystis carinii<ref name="Taylor 2005"/>. The receptor may contribute to the innate immune response to these pathogens. In contrast, the mannose receptor appears to enhance infection of macrophages with mycobacteria, including Mycobacterium tuberculosis. The mannose receptor facilitates entry of mycobacteria into macrophages, where they survive and multiply due to inhibition of phagosome-lysosome fusion<ref name="Kang 2005">Kang PB, Azad AK, Torrelles JB, Kaufman TM, Beharka A, Tibesar E, DesJardin LE, Schlesinger LS (2005) The human macrophage mannose receptor directs Mycobacterium tuberculosis lipoarabinomannan-mediated phagosome biogenesis. J Exp Med 202, 987-999</ref>.
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=%22mannose+receptor%22&maxresults=20 CFG database search results for "mannose receptor"].

=== Glycan profiling ===

The mannose receptor binds carbohydrate structures on serum glycoproteins or the surfaces of pathogens so glycan profiling of mammalian cells is not expected to contribute to the understanding of the biology of this receptor.

=== Glycogene microarray ===

Probes for the mannose receptor are included on the CFG glycogene chip. The CFG analyzed patterns of mannose receptor expression showing expression in a wide range of tissues of immune as well as non-immune origin, consistent with localization in tissue macrophages<ref name="Cornelli 2006"/>.

=== Knockout mouse lines ===
Mice lacking the mannose receptor have been described.<ref name="Swain2003">Swain, SD, Lee, SJ, Nussenzweig, MC, and Harmsen, AG (2003) Absence of the macrophage mannose receptor in mice does not increase susceptibility to Pneumocystis carinii infection in vivo. Infect. Immun. 71, 6213-6221</ref> Before funding for knockout mice was discontinued, the CFG developed the [https://www.functionalglycomics.org/static/consortium/resources/DataCoreFSR.shtml DNA construct] to create a mouse line lacking the scavenger receptor C-type lectin. The construct can now be obtained from the [http://www.mmrrc.org/catalog/StrainCatalogSearchForm.jsp Mutant Mouse Regional Resource Center (MMRRC)] at the University of California, Davis.

=== Glycan array ===
The CFG analyzed the oligosaccharide-binding specificities of the mannose receptor ([http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_PA_v2_411_03292006 example]), showing specificity for high mannose oligosaccharides and structures with terminal 6, 3, or 4-sulfated galactose<ref name="Hsu 2009"/>. See all glycan array results for the mannose receptor [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=mannose%20AND%20receptor&cat=coreh here].

The CFG has also analyzed the oligosaccharide binding-specificities of the other C-type lectins involved in glycoprotein clearance. The scavenger receptor C-type lectin was shown to be highly specific for oligosaccharides containing the Lewisx trisaccharide or related structures<ref name="Coombs 2005">Coombs, PJ, Graham, SA, Drickamer, K, Taylor, ME (2005) Selective binding of the scavenger receptor C-type lectin to LewisX trisaccharide and related glycan ligands. J Biol Chem 280, 22993-22999</ref><ref name="Feinberg 2007">Feinberg H, Taylor ME, Weis WI (2007) Scavenger receptor C-type lectin binds to the leukocyte cell surface glycan Lewis(x) by a novel mechanism. J Biol Chem 282, 17250-17258</ref>. See glycan array data for the human scavenger receptor [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_GLYCAN_v3_72_02172005 here]. See the mouse scavenger receptor data [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_PA_v2.1_478_09272006 here]. Glycan array screening with the major subunit of the asialoglycoprotein receptor showed binding to a broad range of galactose- and GalNAc- terminated oligosaccharides, but indicated stronger binding to structures with terminal GalNAc residues<ref name="Coombs 2006">Coombs, PJ, Taylor, ME, Drickamer, K (2006) Two categories of mammalian galactose-binding receptors distinguished by glycan array profiling. Glycobiology 16, 1C-7C</ref>.

== Related GBPs ==
Asialoglycoprotein receptor [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=asialoglycoprotein+AND+receptor&maxresults=20 (CFG data)], scavenger receptor C-type lectin [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=scavenger+AND+receptor+AND+C-type+AND+lectin&maxresults=20 (CFG data)], Kupffer cell receptor [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=Kupffer+AND+cell+AND+receptor&maxresults=20 (CFG data)], Endo-180.

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Maureen Taylor, Kurt Drickamer

Mannose receptor

2011-04-16T09:12:25Z

Kurt Drickamer: /* Knockout mouse lines */

The mannose receptor represents a paradigm for the involvement of C-type lectins in clearance of circulating glycoproteins. The role of glycan-binding receptors as tags for uptake and turnover was one of the first established functions for endogenous sugar-binding proteins and provides a key model for how glycans can modulate communication between cells in a physiological context. While the asialoglycoprotein receptor would be considered the founder member of this group of receptors, the in vivo evidence for its function is less compelling than the results for the mannose receptor, which has well defined roles in clearance of sulfated glycoprotein hormones as well as mannose-bearing glycoproteins released at sites of inflammation<ref name="Taylor 2005">Taylor PR, Gordon S, Martinez-Pomares L (2005) The mannose receptor: linking homeostasis and immunity through sugar recognition. Trends Immunol 26,104-110</ref>.

In addition to the mannose receptor and the asialoglycoprotein receptor, the scavenger receptor C-type lectin may also be involved in clearance of serum glycoproteins. The asialoglycoprotein receptor and the scavenger receptor C-type lectin have different domain organisations and ligand binding specificities compared to the mannose receptor.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
PIs working with the mannose receptor include: Ten Feizi; Reiko Lee; Yuan Lee; Michel Nussenzweig; Maureen Taylor; Kurt Drickamer; Chi-Huey Wong; Bill Weis; Pauline Rudd; Nathalie Scholler
== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about the mannose receptor, its carbohydrate ligand(s), and how they interact to mediate cell communication. Further information can be found in the GBP Molecule Pages for the [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_hum_Ctlect_00127&sideMenu=no human] and [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_mou_Ctlect_181&sideMenu=no mouse] mannose receptor in the CFG database.

 As in the case of the selectins, much of the evidence for functions of the mannose receptor pre-dates the consortium. However, there have been some further developments for this receptor and other members of the group. PIs have generated and characterized knockout mice, defined the sugar-binding specificities, demonstrated clearance in vivo and endocytosis in tissue culture, and performed structural analysis.
 
=== Carbohydrate ligands ===

The multiple domains in the extracellular region of the mannose receptor allow recognition of a diverse range of glycoconjugate ligands<ref name="Taylor 1990">Taylor, ME, Conary, JT, Lennartz, MR, Stahl, PD, Drickamer, K (1990) Primary structure of the mannose receptor contains multiple motifs resembling carbohydrate-recognition domains.J Biol Chem 265,12156-12162</ref>. Several of the eight C-type carbohydrate-recognition domains are involved in Ca2+-dependent recognition of terminal mannose, GlcNAc or fucose residues on the oligosaccharides of endogenous glycoproteins or the surfaces of microorganisms<ref name="Taylor 1992">Taylor, ME., Bezouska, K, Drickamer, K (1992) Contribution to ligand binding by multiple carbohydrate-recognition domains in the macrophage mannose receptor. J Biol Chem 267, 1710-1726</ref><ref name="Mullin 1997">Mullin, NP, Hitchen, PG, Taylor, ME (1997) Mechanism of 2+- and monosaccharide-binding to a C-type carbohydrate-recognition domain of the macrophage mannose receptor. J Biol Chem 272, 5668-5681</ref>, while the R-type carbohydrate-recognition domain binds sulfated GalNAc and sulfated galactose residues<ref name="Fiete 1998">Fiete DJ, Beranek MC, Baenziger JU (1998) A cysteine-rich domain of the "mannose" receptor mediates GalNAc-4-SO4 binding. Proc Natl Acad Sci USA 95, 2089-2093</ref>. Biological ligands for the mannose receptor include lysosomal hydrolases, the pro-collagen peptides of type I and type III collagens and tissue plasminogen activator – proteins that bear high mannose oligosaccharides and are released from cells at sites of inflammation<ref name="Lee 2002">Lee SJ, Evers S, Roeder D, Parlow AF, Risteli J, Risteli L, Lee YC, Feizi T, Langen H, Nussenzweig MC (2002) Mannose receptor-mediated regulation of serum glycoprotein homeostasis. Science 295, 1898-1901</ref>. The main biological ligands recognized by the R-type carbohydrate-recognition domain are the pituitary hormones lutropin and thyrotropin which bear oligosaccharides terminating in GalNAc-4-SO4<ref name="Fiete 1998"/><ref name="Liu 2000">Liu Y, Chirino AJ, Misulovin Z, Leteux C, Feizi T, Nussenzweig MC, Bjorkman PJ. (2000) Crystal structure of the cysteine-rich domain of the mannose receptor complexed with a sulfated carbohydrate ligand. J Exp Med 191, 1105-1116</ref>.The CFG contributed to defining specificity for oligosaccharides through screening of glycan arrays<ref name="Hsu 2009">Hsu TL, Cheng SC, Yang WB, Chin SW, Chen BH, Huang MT, Hsieh SL, Wong CH (2009) Profiling carbohydrate-receptor interaction with recombinant innate immunity receptor-Fc fusion proteins. J Biol Chem 284, 34479-34489</ref>.
 

=== Cellular expression of GBP and ligands ===

The mannose receptor was first identified in the liver on sinusoidal endothelial cells and Kupffer cells<ref name="Schlesinger 1978">Schlesinger P, Doebber TW, Mandell BF, White R, DeSchryver C, Rodman JS, Miller MJ, Stahl P (1978) Plasma clearance of glycoproteins with terminal mannose and GlcNAc by liver non-parenchymal cells. Biochem J 176, 103-109</ref>. The receptor has since been found on most types of tissue macrophages, including those in the placenta and the brain, but not on circulating monocytes<ref name="Taylor 2005"/>. The mannose receptor is also expressed in the retinal pigmented epithelium<ref name="Greaton 2003">Greaton CJ, Lane KB, Shepherd VL, McLaughlin BJ (2003) Transcription of a single mannose receptor gene by macrophage and retinal pigment epithelium. Opthalmic Res 35, 42-47</ref> and on CD1-positive dendritic cells<ref name="Sallusto 1995">Sallusto F, Cella M, Danieli C, Lanzavecchia A (1995) Dendritic cells use macropinocytosis and the mannose receptor to concentrate macromolecules in the major hitocompatibility complex class II compartment: downregulation by cytokines and bacterial products. J Exp Med 182, 389-400</ref>. The CFG contributed to defining expression of the mannose receptor by glycogene microarray analysis<ref name="Cornelli 2006">Comelli, EM, Head, SR, Gilmartin, T, Whisenant, T, Haslam, SM, North SJ, Wong, N-K, Kudo, T, Narimatsu, H, Esko, JD, Drickamer, K, Dell, A, Paulson, JC (2006) A focused microarray approach to functional glycomics: transcriptional regulation of the glycome. Glycobiology 16, 117-131</ref>
 
=== Biosynthesis of ligands ===
Glycans on endogenous glycoprotein ligands 
Two transferases expressed in the pituitary are required to synthesize the terminal GalNAc-4-SO4 residues found on the oligosaccharides of hormones such as lutropin. The protein-specific glycoprotein hormone N-acetylgalactosaminyltransferase (protein-specific β1,4GalNAcT) adds GalNAc<ref name”Mengeling1995”>Mengeling BJ, Manzella SM, and Baenziger JU (1999) A cluster of basic amino acids within an α-helix is essential for α-subunit recognition by the glycoprotein hormone N-acetylgalactosaminyltransferase. Proc. Natl. Acad. Sci. U.S.A. 92, 502–506</ref> which is then sulfated by a GalNAc-4-sulfotransferase (GalNAc-4-ST1).<ref name”Boregowda”>Boregowda RK, Mi Y, Bu H, and Baenziger JU (2005) Differential expression and enzymatic properties of GalNAc-4-sulfotransferase-1 and GalNAc-4-sulfotransferase-2. Glycobiology 15, 1349–1358</ref>
 
High mannose oligosaccharides on released lysosomal enzymes are generated from mannose 6-phosphate-containing oligosaccharides ([http://www.functionalglycomics.org/CFGparadigms/index.php/Cation-dependent_Mannose-6-phosphate_receptor M6PR]) by phosphatase activity.
 
Glycans on micro-organisms 
Biosynthesis mannans on fungi has been well studied in a number of species. For example, in the yeast S. cerevisiae, the KRE2/MNT1 genes encode mannosyltransferases that synthesize both N- and O-linked mannans.<ref name”Lussier1999”>Lussier, M, Sdicu, A-M and Bussey, H (1999) The KTR and MNN1 mannosyltransferase families of Saccharomyces cerevisiae. Biochim. Biophys. Acta 1426, 323-334</ref>
 
The mycobacterial transferases for synthesis of the lipo-arabinomannan (LAM) core and the extended ManLAM structures have been characterized.<ref name”Tam2009”>Tam, P-H and Lowary, TL (2009) Recent advances in mycobacterial cell wall glycan biosynthesis. Cur. Opin Struct. Biol. 13, 618-625</ref>
 

=== Structure ===

[[image:Mannose_receptor.jpg]]

The mannose receptor is a type I transmembrane protein, with a large extracellular domain containing three types of domain. An N-terminal R-type carbohydrate-recognition domain is followed by a fibronectin type II domain and eight C-type carbohydrate-recognition domains<ref name="Taylor 1990"/>. The short cytoplasmic C-terminal domain contains a di-aromatic motif essential for rapid internalization and endosomal sorting<ref name="Schweizer 2000">Schweizer A, Stahl PD, Rohrer J (2000) A di-aromatic motif in the cytosolic tail of the mannose receptor mediates endosomal sorting. J Biol Chem 275, 29694-29700</ref>. The structures of two portions of the extracellular domain of the mannose receptor have been determined. The structure of CRD-4 that has been determined represents the conformation when the receptor relases ligand under endosomal conditions ([http://www.rcsb.org/pdb/explore/explore.do?structureId=1EGG CRD-4]). The structure of the R-type CRD has been determined with bound SO4-GalNAc as well as with other sulfated ligands ([http://www.rcsb.org/pdb/explore/explore.do?structureId=1DQO R-type CRD with SO4-GalNAc]). 

Three other endocytic receptors, DEC-205, Endo-180 and the phospholipase A2 receptor, share the same domain organization as the mannose receptor<ref name="Taylor 1997">Taylor, ME (1997) Evolution of a family of receptors containing multiple C-type carbohydrate-recognition domains. Glycobiology 7, v-viii</ref>. Of these, only Endo-180 has been shown to bind carbohydrate ligands.
 

=== Biological roles of GBP-ligand interaction ===

The mannose receptor mediates endocytosis of glycoproteins. Ligand-receptor complexes are internalized via clathrin-coated pits into early endosomes where the ligands are released and targeted to the lysosome for degradation<ref name="Schweizer 2000"/>. The mannose receptor acts to regulate serum levels of proteins such as lysosomal enzymes that are released from cells during inflammation<ref name="Lee 2002"/>. The mannose receptor also regulates levels of pituitary hormones such as lutropin and thyrotropin that must be removed from serum once they have acted on their target cells<ref name="Shapiro 2002">Mi Y, Shapiro SD, Baenziger JU (2002) Regulation of lutropin circulatory half-life by the mannose/N-acetylgalactosamine-4-SO4 receptor is critical for implantation in vivo. J Clin Invest 109, 269-276</ref>. The mannose receptor can also bind and mediate internalization of a wide variety of pathogenic micro-organisms including HIV, the fungi Candida albicans and Aspergillus fumigatus, parasites such as Leishmania donovani and bacteria including Pneumocystis carinii<ref name="Taylor 2005"/>. The receptor may contribute to the innate immune response to these pathogens. In contrast, the mannose receptor appears to enhance infection of macrophages with mycobacteria, including Mycobacterium tuberculosis. The mannose receptor facilitates entry of mycobacteria into macrophages, where they survive and multiply due to inhibition of phagosome-lysosome fusion<ref name="Kang 2005">Kang PB, Azad AK, Torrelles JB, Kaufman TM, Beharka A, Tibesar E, DesJardin LE, Schlesinger LS (2005) The human macrophage mannose receptor directs Mycobacterium tuberculosis lipoarabinomannan-mediated phagosome biogenesis. J Exp Med 202, 987-999</ref>.
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=%22mannose+receptor%22&maxresults=20 CFG database search results for "mannose receptor"].

=== Glycan profiling ===

The mannose receptor binds carbohydrate structures on serum glycoproteins or the surfaces of pathogens so glycan profiling of mammalian cells is not expected to contribute to the understanding of the biology of this receptor.

=== Glycogene microarray ===

Probes for the mannose receptor are included on the CFG glycogene chip. The CFG analyzed patterns of mannose receptor expression showing expression in a wide range of tissues of immune as well as non-immune origin, consistent with localization in tissue macrophages<ref name="Cornelli 2006"/>.

=== Knockout mouse lines ===
Mice lacking the mannose receptor have been described.<ref name="Swain2003">Swain, SD, Lee, SJ, Nussenzweig, MC, and Harmsen, AG (2003) Absence of the macrophage mannose receptor in mice does not increase susceptibility to Pneumocystis carinii infection in vivo. Infect. Immun. 71, 6213-6221</ref> Before funding for knockout mice was discontinued, the CFG developed the [https://www.functionalglycomics.org/static/consortium/resources/DataCoreFSR.shtml DNA construct] to create a mouse line lacking the scavenger receptor C-type lectin. The construct can now be obtained from the [http://www.mmrrc.org/catalog/StrainCatalogSearchForm.jsp Mutant Mouse Regional Resource Center (MMRRC)] at the University of California, Davis.

=== Glycan array ===
The CFG analyzed the oligosaccharide-binding specificities of the mannose receptor ([http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_PA_v2_411_03292006 example]), showing specificity for high mannose oligosaccharides and structures with terminal 6, 3, or 4-sulfated galactose<ref name="Hsu 2009"/>. See all glycan array results for the mannose receptor [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=mannose%20AND%20receptor&cat=coreh here].

The CFG has also analyzed the oligosaccharide binding-specificities of the other C-type lectins involved in glycoprotein clearance. The scavenger receptor C-type lectin was shown to be highly specific for oligosaccharides containing the Lewisx trisaccharide or related structures<ref name="Coombs 2005">Coombs, PJ, Graham, SA, Drickamer, K, Taylor, ME (2005) Selective binding of the scavenger receptor C-type lectin to LewisX trisaccharide and related glycan ligands. J Biol Chem 280, 22993-22999</ref><ref name="Feinberg 2007">Feinberg H, Taylor ME, Weis WI (2007) Scavenger receptor C-type lectin binds to the leukocyte cell surface glycan Lewis(x) by a novel mechanism. J Biol Chem 282, 17250-17258</ref>. See glycan array data for the human scavenger receptor [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_GLYCAN_v3_72_02172005 here]. See the mouse scavenger receptor data [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_PA_v2.1_478_09272006 here]. Glycan array screening with the major subunit of the asialoglycoprotein receptor showed binding to a broad range of galactose- and GalNAc- terminated oligosaccharides, but indicated stronger binding to structures with terminal GalNAc residues<ref name="Coombs 2006">Coombs, PJ, Taylor, ME, Drickamer, K (2006) Two categories of mammalian galactose-binding receptors distinguished by glycan array profiling. Glycobiology 16, 1C-7C</ref>.

== Related GBPs ==
Asialoglycoprotein receptor [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=asialoglycoprotein+AND+receptor&maxresults=20 (CFG data)], scavenger receptor C-type lectin [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=scavenger+AND+receptor+AND+C-type+AND+lectin&maxresults=20 (CFG data)], Kupffer cell receptor [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=Kupffer+AND+cell+AND+receptor&maxresults=20 (CFG data)], Endo-180

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Maureen Taylor, Kurt Drickamer

Macrophage galactose lectin (MGL)

2011-04-16T09:02:54Z

Kurt Drickamer: /* Knockout mouse lines */

Macrophage galactose binding lectin (MGL) is the best studied of the multiple C-type lectins on macrophages <ref name="Kawasaki 1986">Kawasaki T, Ii M, Kozutsumi Y and Yamashina I. 1986. Isolation and characterization of a receptor lectin specific for galactose/N-acetylgalactosamine from macrophages. Carbohydr Res. 151:197-206</ref><ref name="Suzuki 1996">Suzuki N, Yamamoto K, Toyoshima S, Osawa T and Irimura T. 1996. Molecular cloning and expression of cDNA encoding human macrophage C-type lectin. Its unique carbohydrate binding specificity for Tn antigen. J Immunol. 156:128-135</ref>. It is also representative of the subclass of C-type lectins that bind galactose-related sugars. MGL consists of one CRD domain and contains cytoplasmic internalization motifs for endocytosis. No signaling properties have been described yet for MGL. Human MGL (CD301) and rat MGL are encoded by a single gene, whereas mice contain two MGL copies, mMGL-1 and mMGL-2 that differ in carbohydrate specificity <ref name=Tsuiji 2002">Tsuiji M, Fujimori M, Ohashi Y, Higashi N, Onami TM, Hedrick SM and Irimura T. 2002. Molecular cloning and characterization of a novel mouse macrophage C-type lectin, mMGL2, which has a distinct carbohydrate specificity from mMGL1. J Biol Chem. 277:28892-28901</ref><ref name="Singh 2009">Singh SK, Streng-Ouwehand I, Litjens M, Weelij DR, Garca-Vallejo JJ, van Vliet SJ, Saeland E, van Kooyk Y. 2009. Characterization of murine MGL1 and MGL2 C-type lectins: distinct glycan specificities and tumor binding properties. Mol Immunol 46: 1240-1249</ref><ref name="Higashi 2002">Higashi N, Fujioka K, Denda-Nagai K, Hashimoto S, Nagai S, Sato T, Fujita Y, Morikawa A, Tsuiji M, Miyata-Takeuchi M, Sano Y, Suzuki N, Yamamoto K, Matsushima K and Irimura T. 2002. The macrophage C-type lectin specific for galactose/N-acetylgalactosamine is an endocytic receptor expressed on monocyte-derived immature dendritic cells. J Biol Chem. 277:20686-20693</ref>.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
In addition to creating the knockout for the two mouse forms of MGL, PIs have been involved in extensive studies of binding specificity and mechanism of ligand binding as well as the role of the receptor in macrophage signaling.
* PIs working on MGL include: Nicolai Bovin, Kurt Drickamer, Toshisuke Kawasaki, Cheng Liu, Yvette van Kooyk, Hui Wu, Joy Burchell,Joyce Taylor-Papadimitriou
* Non-PIs with who have used CFG resources to study MGL include: Siamon Gordon, Alan Saltiel
* PIs working on MGL-related glycan-binding proteins (GBPs), particularly Mincle, include: Anthony dApice, Joshua Fierer, Rikard Holmdahl, Christopher O'Callaghan, Judy Teale, Christine Wells
* Non-PIs with who have used resources to study related members of this paradigm group include: Roland Lang, Ulrich Maus, Gunnar Nilsson, Kenneth Rock

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about MGL, its carbohydrate ligand(s), and how they interact to mediate cell communication. Further information about MGL can be found in its [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_hum_Ctlect_217&sideMenu=no GBP Molecule Page] in the CFG database.
=== Carbohydrate ligands ===
*mMGL1 binds Lewis X and Lewis A structures, whereas mMGL2 recognizes N-acetylgalactosamine (GalNAc) and galactose, including the O-linked Tn-antigen and TF-antigen <ref name=Tsuiji 2002"/><ref name="Singh 2009"/><Ref name="Napoletano2007"/>
*hMGL binds terminal α- and β-linked GalNAc residues on glycoproteins, glycolipids and bacterial LPS, including Tn antigen and GalNAcβ1-4GlcNAc-R (LDN) antigens <ref name="Suzuki 1996"/><ref name="Van Vliet 2005">van Vliet SJ, van Liempt E, Saeland E, Aarnoudse CA, Appelmelk B, Irimura T, Geijtenbeek TB, Blixt O, Alvarez R, van Die I and van Kooyk Y. 2005. Carbohydrate profiling reveals a distinctive role for the C-type lectin MGL in the recognition of helminth parasites and tumor antigens by dendritic cells. Int Immunol. 17:661-669</ref><ref>van Sorge NM, Bleumink NM, van Vliet SJ, Saeland E, van der Pol WL, van Kooyk Y and van Putten JP. 2009. N-glycosylated proteins and distinct lipooligosaccharide glycoforms of Campylobacter jejuni target the human C-type lectin receptor MGL. Cell Microbiol. 11:1768-1781</ref><ref>Saeland E, van Vliet SJ, Backstrom M, van den Berg VC, Geijtenbeek TB, Meijer GA and van Kooyk Y. 2007. The C-type lectin mgl expressed by dendritic cells detects glycan changes on Muc1 in colon carcinoma. Cancer Immunol Immunother. 56:1225-1236</ref><ref name="Napoletano2007">Napoletano C, Rughetti A, Tarp M.P.A, Coleman J Bennett,E.P, Picco G, Sale P, Denda-Hagai K, Irimura T, Mandel U, Clausen H, Frati L, Taylor-Papadimitriou J, Burchell J, Nuti M. Tumour associated Tn-MUC1 glycoform is internalised througfh the macrophage galactose C-type lectin and delivered to the HLA class I and Class II compartments in dendritic cells. Cancer Research, 2007, 67(17): 8358-8367</ref>.
*hMGL can also bind to STn when presented on a peptide or polyacrylamide backbone.

=== Cellular expression of GBP and ligands ===
MGL is expressed on dendritic cells and macrophages. <ref name="Higashi 2002"/><ref name=" van Vliet SJ1200 ">van Vliet SJ, Gringhuis SI, Geijtenbeek TB and van Kooyk Y. 2006. Regulation of effector T cells by antigen-presenting cells via interaction of the C-type lectin MGL with CD45. Nat Immunol. 7:1200-1208</ref>
 
The Tn ligand is expressed by many cancer cells especially breast cancers where it is expressed on more than 90% of breast carcinomas <ref> Sørensen AL, “et al”. Chemoenzymatically synthesized multimeric Tn/STn MUC1 glycopeptides elicit cancer-specific anti-MUC1 antibody responses and override tolerance. “Glycobiology” 16, 96-107 (2006) </ref>. although STn is also expressed by carcinomas, especially colorectal and in 25-30% of breast cancers.

=== Biosynthesis of ligands ===
The Tn ligand can be expressed in cervical cancer due to mutations in Cosmc <ref> Ju T, “et al”. Human tumor antigens Tn and sialyl Tn arise from mutations in Cosmc “Cancer Research” 68, 1636-1646 (2008) </ref>. a molecular chaperone that is essential for the activity of the T synthase, the glycosyltransferase that catalyses the addition Gal to GalNAcαSer/Thr, forming the T antigen (Galβ1,3GalNAcαSer/Thr).
Although the vast majority of breast cancers express Tn there is no evidence of mutated Cosmc in these cancers therefore another mechanism for the expression of the Tn ligand must be active. Moreover the expression of STn in breast cancer is perfectly correlated with the turning on of the transcription of ST6GalNAc-I <ref> Sewell R, “et al”. The ST6GalNAc-I sialyltransferase localizes throughout the Golgi and is responsible for the synthesis of the tumor-associated sialyl-Tn O-glycan in human breast cancer. “J Biol Chem” 281, 3586-3594 (2006) </ref>.
 

=== Structure ===
[[image:MGL.jpg]] 
MGL is an oligomeric type II transmembrane protein. The CRD of the major subunit of the hepatic asialoglycoprotein receptor has been determined<ref name="Meier2000">Meier, M, Bider, MD, Malashkevich, VN, Spiess, M and Burkhard, P. 2000. Crystal structure of the carbohydrate recognition domain of the H1 subunit of the asialoglycoprotein receptor. J Mol Biol 300:857–865</ref> and the structure of a galatose-binding mutant of mannose-binding protein provides experimental evidence for how galactose- and GalNAc-terminated ligands can bind to the receptor.<ref name="Kolatkar2000">Kolatkar, AR, Leung, AK, Isecke, R, Brossmer, R, Drickamer, K and Weis, WI. 1998. Mechanism of N-acetylgalactosamine binding to a C-type animal lectin carbohydrate-recognition domain. J Biol Chem 273:19502-19508</ref>
 

=== Biological roles of GBP-ligand interaction ===
*MGL is a highly efficient internalization receptor <ref name="Higashi 2002"/><ref>Valladeau J, Duvert-Frances V, Pin JJ, Kleijmeer MJ, Ait-Yahia S, Ravel O, Vincent C, Vega F, Jr., Helms A, Gorman D, Zurawski SM, Zurawski G, Ford J and Saeland S. 2001. Immature human dendritic cells express asialoglycoprotein receptor isoforms for efficient receptor-mediated endocytosis. J Immunol. 167:5767-5774</ref>
*hMGL regulates T-cell receptor mediated signaling and T-cell dependent cytokine responses <ref name=" van Vliet SJ1200 "/>
*mMGL1 promotes adipose tissue inflammation and insulin resistance <ref>Westcott DJ, Delproposto JB, Geletka LM, Wang T, Singer K, Saltiel AR, Lumeng CN. 2009. MGL1 promotes adipose tissue inflammation and insulin resistance by regulating 7/4hi monocytes in obesity. J Exp Med 206: 3143-56</ref>
*mMGL2 promotes enhances both MHC class II and class I presentation antigen in dendritic cells (DCs) <ref>Singh SK, Streng-Ouwehand I, Litjens M, Kalay H, Saeland E, Van Kooyk Y. 2010. Tumour-associated glycan modifications of antigen enhance MGL2 dependent uptake and MHC class I restricted CD8 T cell responses. Int. J. Cancer, in press</ref>

 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=MGL&maxresults=20 CFG database search results for MGL].

=== Glycan profiling ===

 
=== Glycogene microarray ===
Probes for the single human MGL and both mouse MGLs have been included in all versions of the CFG glycogene chip.
 

=== Knockout mouse lines ===
Mice lacking MGL-1<ref name=Onami2002>Onami, TM, Lin, M-Y, Page, DM, Shirley A. Reynolds, SA, Katayama, CD, Marth, JD, Irimura, T, Varki, A, Varki, N and Hedrick SM (2002) Generation of mice deficient for dacrophage galactose- and N-acetylgalactosamine-specific lectin: limited role in lymphoid and erythroid homeostasis and evidence for multiple lectins. Mol. Cell. Biol. 22, 5173-5181</ref> were distributed by the CFG and the [https://www.functionalglycomics.org/glycomics/publicdata/phenotyping.jsp phenotype] was analyzed. Mice lacking MGL-2 have also been described.<ref name="Denda2010">Denda-Nagai, K, Aida, S, Saba, K, Suzuki, K, Moriyama, S, Oo-puthinan, S, Tsuiji, M, Morikawa, A, Kumamoto, Y, Sugiura, D, Kudo, A, Akimoto, Y, Kawakami, H, Bovin NV, and Irimura, T (2010) Distribution and function of macrophage galactose-type C-type lectin 2 (MGL2/CD301b): efficient uptake and presentation of glycosylated antigens by dendritic cells. J. Biol. Chem. 285, 19193–19204</ref> ES cells for an MGL-1/2 double knockout, generated in Core F, are available from [http://www.functionalglycomics.org/static/consortium/resources/resourcecoref.shtml#table1 MMRRC].

=== Glycan array ===
The glycan-binding specificity of [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_GLYCAN_v2_13_11262003 human] and [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_2010 mouse] versions of MGL have been analyzed by glycan array screening <ref name="Van Vliet 2005"/><ref name="Singh 2009"/>. See all glycan array results for MGL [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=mgl&cat=coreh here]. See glycan array results for these related GBPs: [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=mannose%20AND%20receptor%20NOT%20asialoglycoprotein&cat=coreh mannose receptor,] [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=mincle&cat=coreh mincle,] [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=MCL&cat=coreh macrophage C-type lectin (MCL),] and [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=dectin-1&cat=coreh dectin-1.]

== Related GBPs ==
Other C-type lectins on macrophages include the mannose receptor [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=DC-SIGNR&maxresults=20 (CFG data)], mincle <ref>Wells CA, Salvage-Jones JA, Li X, Hitchens K, Butcher S, Murray RZ, Beckhouse AG, Lo YL, Manzanero S, Cobbold C, Schroder K, Ma B, Orr S, Stewart L, Lebus D, Sobieszczuk P, Hume DA, Stow J, Blanchard H, Ashman RB. 2008. The macrophage-inducible C-type lectin, mincle, is an essential component of the innate immune response to Candida albicans. J Immunol 180: 7404-7413</ref> [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=mincle&maxresults=20 (CFG data)], macrophage C- type lectin (MCL) [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=MCL&maxresults=20 (CFG data)], and dectin-1 [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=dectin-1&maxresults=20 (CFG data)].

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Kurt Drickamer, Joyce Taylor-Papadimitriou, Yvette van Kooyk, Irma van Die

Parainfluenza virus type 3 hemagglutinin-neuraminidase

2011-04-15T09:06:59Z

Kurt Drickamer: /* Biosynthesis of ligands */

Human parainfluenza viruses (HPIVs) are a group of respiratory viruses associated with human respiratory diseases including bronchitis, bronchiolitis, and pneumonia<ref>Moscona, A. 2005. Entry of parainfluenza virus into cells as a target for interrupting childhood respiratory disease. J Clin Invest 115(7):1688-98.</ref><ref>Sato, M. and P.F. 2008. Current status of vaccines for parainfluenza virus infections. Pediatr Infect Dis J 27(10 Suppl):S123-5.</ref><ref>Johnstone, J., S.R. Majumdar, J.D. Fox, and T.J. Marrie. 2008. Viral infection in adults hospitalized with community-acquired pneumonia: prevalence, pathogens, and presentation. Chest 134(6):1141-8.</ref>. Paramyxoviruses, including HPIVs, possess an envelope protein hemagglutinin-neuraminidase (HN) that has receptor-cleaving as well as receptor-binding activity where the two activities reside on the same glycoprotein unlike influenza which carries hemagglutinin and neuraminidase activities as individual glycoproteins. HN is also essential for activating the fusion protein (F) to mediate merger of the viral envelope with the host cell membrane <ref name="Lamb1993">Lamb, R. 1993. Paramyxovirus fusion: A hypothesis for changes. Virology 197:1-11.</ref><ref name="Iorio2009">Iorio, R.M., V.R. Melanson, and P.J. Mahon. 2009. Glycoprotein interactions in paramyxovirus fusion. Future Virol 4(4):335-351.</ref>. For the parainfluenza viruses as well as other HN-containing paramyxoviruses, this single molecule carries out three different but critical activities at specific points in the process of viral entry. The first step in infection by HPIV is binding to the lung cells’ surface via interaction of the viral receptor-binding molecule with sialic acid-containing receptor molecules on the cell surface <ref name="Suzuki2001">Suzuki, T., A. Portner, R.A. Scroggs, M. Uchikawa, N. Koyama, et al. 2001. Receptor specificities of human respiroviruses. J Virol 75(10):4604-13.</ref><ref name="Moscona2010">Moscona, A., M. Porotto, S. Palmer, C. Tai, L. Aschenbrenner, et al. 2010. A Recombinant Sialidase Fusion Protein Effectively Inhibits Human Parainfluenza Viral Infection In Vitro and In Vivo. J Infect Dis.</ref>.
Structures of three paramyxovirus HNs have been determined; they are Newcastle Disease virus (NDV), HPIV type 3, and HPIV type 5 (formerly called SV5). Determination of the HN structure of hPIV3 (globular domain) show an enzyme active site very similar to that of influenza neuraminidase and PIV5 HN and this appears to also be a binding site. A second site at the dimer interface has been crystallographically determined only for Newcastle Disease virus (NDV) HN, but a rising number of reports postulate the presence of such a second site for other paramyxoviruses <ref>Zaitsev, V., M. von Itzstein, D. Groves, M. Kiefel, T. Takimoto, et al. 2004. Second sialic acid binding site in newcastle disease virus hemagglutinin-neuraminidase: implications for fusion. J Virol 78(7):3733-41.</ref><ref>Lawrence, M.C., N.A. Borg, V.A. Streltsov, P.A. Pilling, V.C. Epa, et al. 2004. Structure of the Haemagglutinin-neuraminidase from Human Parainfluenza Virus Type III. J Mol Biol 335(5):1343-57.</ref><ref>Yuan, P., T.B. Thompson, B.A. Wurzburg, R.G. Paterson, R.A. Lamb, et al. 2005. Structural studies of the parainfluenza virus 5 hemagglutinin-neuraminidase tetramer in complex with its receptor, sialyllactose. Structure 13(5):803-15.</ref><ref>Lamb, R.A., R.G. Paterson, and T.S. Jardetzky. 2005. Paramyxovirus membrane fusion: lessons from the F and HN atomic structures. Virology 344(1):30-7.</ref><ref>Bousse, T. and T. Takimoto. 2006. Mutation at residue 523 creates a second receptor binding site on human parainfluenza virus type 1 hemagglutinin-neuraminidase protein. J Virol 80(18):9009-16.</ref><ref>Porotto, M., M. Fornabaio, G. Kellogg, and A. Moscona. 2007. A second receptor binding site on the human parainfluenza 3 hemagglutinin-neuraminidase contributes to activation of the fusion mechanism. J Virol 81(7):3216-3228.</ref>. Interestingly for NDV HN, functional analysis of the two sites indicated that engagement of the first site activates the second <ref>Porotto, M., M. Fornabaio, O. Greengard, M.T. Murrell, G.E. Kellogg, et al. 2006. Paramyxovirus receptor-binding molecules: engagement of one site on the hemagglutinin-neuraminidase protein modulates activity at the second site. J Virol 80(3):1204-13.</ref><ref>Ryan, C., V. Zaitsev, D.J. Tindal, J.C. Dyason, R.J. Thomson, et al. 2006. Structural analysis of a designed inhibitor complexed with the hemagglutinin-neuraminidase of Newcastle disease virus. Glycoconj J 23(1-2):135-41.</ref>. Further studies on the relationship between the sialic acid binding and cleavage activity of wildtype and mutant HPIV HNs are ongoing among CFG PIs. A region next to the transmembrane domain of HN (stalk region) is still elusive to crystal determination, however several studies showed the importance of this domain in fusion promotion <ref>Melanson, V.R. and R.M. Iorio. 2004. Amino acid substitutions in the F-specific domain in the stalk of the newcastle disease virus HN protein modulate fusion and interfere with its interaction with the F protein. J Virol 78(23):13053-61.</ref><ref>Melanson, V.R. and R.M. Iorio. 2006. Addition of N-glycans in the stalk of the Newcastle disease virus HN protein blocks its interaction with the F protein and prevents fusion. J Virol 80(2):623-33.</ref><ref>Porotto, M., M. Murrell, O. Greengard, and A. Moscona. 2003. Triggering of human parainfluenza virus 3 fusion protein(F) by the hemagglutinin-neuraminidase (HN): an HN mutation diminishing the rate of F activation and fusion. J Virol 77(6):3647-3654.</ref><ref>Bishop, K.A., A.C. Hickey, D. Khetawat, J.R. Patch, K.N. Bossart, et al. 2008. Residues in the stalk domain of the hendra virus g glycoprotein modulate conformational changes associated with receptor binding. J Virol 82(22):11398-409.</ref>.

To further emphasize the importance of understanding GBP paradigms, CFG PIs have shown that HPIV3 infection in cultured monolayer cells greatly differs from infection in human airway epithelial (HAE) cell cultures or in animal models <ref>Zhang, L., M.E. Peeples, R.C. Boucher, P.L. Collins, and R.J. Pickles. 2002. Respiratory syncytial virus infection of human airway epithelial cells is polarized, specific to ciliated cells, and without obvious cytopathology. J Virol 76(11):5654-66.</ref><ref>Mellow, T.E., P.C. Murphy, J.L. Carson, T.L. Noah, L. Zhang, et al. 2004. The effect of respiratory synctial virus on chemokine release by differentiated airway epithelium. Exp Lung Res 30(1):43-57.</ref><ref>Zhang, L., A. Bukreyev, C.I. Thompson, B. Watson, M.E. Peeples, et al. 2005. Infection of ciliated cells by human parainfluenza virus type 3 in an in vitro model of human airway epithelium. J Virol 79(2):1113-24.</ref><ref>Thompson, C.I., W.S. Barclay, M.C. Zambon, and R.J. Pickles. 2006. Infection of human airway epithelium by human and avian strains of influenza A virus. J Virol 80(16):8060-8.</ref>. HPIV3 with a single amino acid mutation in the HN glycoprotein with better than wildtype growth in cell culture had a disadvantage in an ex vivo or in vivo system, revealing a gap in our understanding of the biology of these viruses in their natural host <ref>Palermo, L., M. Porotto, C. Yokoyama, S. Palmer, B. Mungall, et al. 2009. Human parainfluenza virus infection of the airway epithelium: the viral hemagglutinin-neuraminidase regulates fusion protein activation and modulates infectivity. J Virol 83(13):6900-6908.</ref>. This suggests that even slight variations in receptor types may influence HPIV infectivity. Recently a series of studies using glycoarray analysis started to navigate the complexity of the interaction between these viruses and glycomolecules <ref>Amonsen, M., D.F. Smith, R.D. Cummings, and G.M. Air. 2007. Human parainfluenza viruses hPIV1 and hPIV3 bind oligosaccharides with alpha2-3-linked sialic acids that are distinct from those bound by H5 avian influenza virus hemagglutinin. J Virol 81(15):8341-5.</ref>. The three functions of HN depend upon interaction with glycomolecules, therefore understanding whether glycomolecules are preferentially bound, cleave, or activate the fusion process will unravel the biology of these viruses and will help in developing targeted antivirals.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
CFG Participating Investigators (PIs) contributing to the understanding of parainfluenza virus type 3 HN include: Gillian Air, Theodore Jardetsky, Matteo Porotto, Charles Russell

== Progress toward understanding this GBP paradigm ==

=== Carbohydrate ligands ===

Parainfluenza virus type 3 hemagglutinin-neuraminidase binds sialylated glycans. The sialic acid is linked α2-3 to galactose. The minimal binding motif is a pentasaccharide if there are no modifications, but smaller units bind if there is sulfation or fucosylation, as shown in the figure below <ref>Amonsen, M., D.F. Smith, R.D. Cummings, and G.M. Air. 2007. Human parainfluenza viruses hPIV1 and hPIV3 bind oligosaccharides with alpha2-3-linked sialic acids that are distinct from those bound by H5 avian influenza virus hemagglutinin. J Virol 81(15):8341-5.</ref>
 [[File: PIV3glycans.png]]

=== Cellular expression of GBP and ligands ===

Parainfluenza virus type 3 hemagglutinin-neuraminidase is expressed by HPIV paramyxoviruses that bind to sialic acid-containing receptor molecules on the surface of host lung cells.

=== Biosynthesis of ligands ===
The parainfluenza viruses type 3 ligands are typical of complex N-linked glycans. The sialyltransferases that generate the PIV3 receptors are [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_624&sideMenu=true&pageType=general ST3GalIII], [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_625&sideMenu=true&pageType=general ST3GalIV], [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_627&sideMenu=true&pageType=general ST3GalVI] along with fucosyl transferases [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_601&sideMenu=true&pageType=general Fuc-TIV] and [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_604&sideMenu=true&pageType=general Fuc-TVII] that generate Sialyl-Lewis x.
 

=== Structure ===
The crystal structure of a hPIV3 HN has been determined in dimer form <ref>Lawrence, M.C., N.A. Borg, V.A. Streltsov, P.A. Pilling, V.C. Epa, et al. 2004. Structure of the Haemagglutinin-neuraminidase from Human Parainfluenza Virus Type III. J Mol Biol 335(5):1343-57.</ref> and serves as the model for glycan binding and neuraminidase studies.
 
The subunits are colored green and blue. A molecule of inhibitor 2-deoxy-2,3-dehydro-N-acetyl-neuraminic acid is bound to the active site of each subunit (stick model: C, O and N atoms are gray, red and blue respectively). The figure was made using PyMol (Delano Scientific) from PDB file 1V3D.
 
[[file: 1V3D.png]]
 

=== Biological roles of GBP-ligand interaction ===
hPIV HN plays important roles in several distinct steps associated with viral entry, which causes human respiratory infections. For the parainfluenza viruses as well as other paramyxoviruses that utilize hemagglutinin-neuraminidases, the HN protein carries out three different activities in the process of viral entry and release: (1) The first step in infection by human parainfluenza virus is binding to the lung cell surface via interaction of HN with sialic acid-containing receptor molecules on the cell surface.<ref name="Suzuki2001"/><ref name="Moscona2010"/> (2) HN is also essential for activating the fusion protein to mediate merger of the viral envelope with the host cell membrane.<ref name="Lamb1993"/><ref name="Iorio2009"/> (3) Finally, the neuraminidase activity of HN is required for release of the virus from cells.
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=parainfluenza&maxresults=20 CFG database search results for "parainfluenza"].

=== Glycan profiling ===
Receptors for hPIV3 are located in the human respiratory tract. Glycan profiling of human lung tissue has been carried out by the CFG Core C [http://www.functionalglycomics.org/glycomics/publicdata/glycoprofiling-new.jsp].
 

=== Glycogene microarray ===
hPIV HN is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
No experiments have been published using glycosyltransferase knockout mice.
 

=== Glycan array ===
There have been many resource requests for glycan array screening of paramyxovirus hemagglutinin-neuraminidase (for example, click [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_2490 here]). To see all glycan array results for parainfluenza hemagglutinin-neuraminidase, click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=parainfluenza&cat=coreh here].

== Related GBPs ==
* Other paramyxovirus HNs: some appear to have one site that carries out both activities; others appear to have separate sites. For glycan array results of other paramyxovirus HNs, click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=paramyxovirus&cat=coreh here].
* Human parainfluenza types 1, 2, 4 and 5
* Newcastle Disease virus
* Mumps virus

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Gillian Air, James Paulson, Matteo Porotto

[[Category:Introduction]]

Parainfluenza virus type 3 hemagglutinin-neuraminidase

2011-04-15T09:03:40Z

Kurt Drickamer: /* Biosynthesis of ligands */

Human parainfluenza viruses (HPIVs) are a group of respiratory viruses associated with human respiratory diseases including bronchitis, bronchiolitis, and pneumonia<ref>Moscona, A. 2005. Entry of parainfluenza virus into cells as a target for interrupting childhood respiratory disease. J Clin Invest 115(7):1688-98.</ref><ref>Sato, M. and P.F. 2008. Current status of vaccines for parainfluenza virus infections. Pediatr Infect Dis J 27(10 Suppl):S123-5.</ref><ref>Johnstone, J., S.R. Majumdar, J.D. Fox, and T.J. Marrie. 2008. Viral infection in adults hospitalized with community-acquired pneumonia: prevalence, pathogens, and presentation. Chest 134(6):1141-8.</ref>. Paramyxoviruses, including HPIVs, possess an envelope protein hemagglutinin-neuraminidase (HN) that has receptor-cleaving as well as receptor-binding activity where the two activities reside on the same glycoprotein unlike influenza which carries hemagglutinin and neuraminidase activities as individual glycoproteins. HN is also essential for activating the fusion protein (F) to mediate merger of the viral envelope with the host cell membrane <ref name="Lamb1993">Lamb, R. 1993. Paramyxovirus fusion: A hypothesis for changes. Virology 197:1-11.</ref><ref name="Iorio2009">Iorio, R.M., V.R. Melanson, and P.J. Mahon. 2009. Glycoprotein interactions in paramyxovirus fusion. Future Virol 4(4):335-351.</ref>. For the parainfluenza viruses as well as other HN-containing paramyxoviruses, this single molecule carries out three different but critical activities at specific points in the process of viral entry. The first step in infection by HPIV is binding to the lung cells’ surface via interaction of the viral receptor-binding molecule with sialic acid-containing receptor molecules on the cell surface <ref name="Suzuki2001">Suzuki, T., A. Portner, R.A. Scroggs, M. Uchikawa, N. Koyama, et al. 2001. Receptor specificities of human respiroviruses. J Virol 75(10):4604-13.</ref><ref name="Moscona2010">Moscona, A., M. Porotto, S. Palmer, C. Tai, L. Aschenbrenner, et al. 2010. A Recombinant Sialidase Fusion Protein Effectively Inhibits Human Parainfluenza Viral Infection In Vitro and In Vivo. J Infect Dis.</ref>.
Structures of three paramyxovirus HNs have been determined; they are Newcastle Disease virus (NDV), HPIV type 3, and HPIV type 5 (formerly called SV5). Determination of the HN structure of hPIV3 (globular domain) show an enzyme active site very similar to that of influenza neuraminidase and PIV5 HN and this appears to also be a binding site. A second site at the dimer interface has been crystallographically determined only for Newcastle Disease virus (NDV) HN, but a rising number of reports postulate the presence of such a second site for other paramyxoviruses <ref>Zaitsev, V., M. von Itzstein, D. Groves, M. Kiefel, T. Takimoto, et al. 2004. Second sialic acid binding site in newcastle disease virus hemagglutinin-neuraminidase: implications for fusion. J Virol 78(7):3733-41.</ref><ref>Lawrence, M.C., N.A. Borg, V.A. Streltsov, P.A. Pilling, V.C. Epa, et al. 2004. Structure of the Haemagglutinin-neuraminidase from Human Parainfluenza Virus Type III. J Mol Biol 335(5):1343-57.</ref><ref>Yuan, P., T.B. Thompson, B.A. Wurzburg, R.G. Paterson, R.A. Lamb, et al. 2005. Structural studies of the parainfluenza virus 5 hemagglutinin-neuraminidase tetramer in complex with its receptor, sialyllactose. Structure 13(5):803-15.</ref><ref>Lamb, R.A., R.G. Paterson, and T.S. Jardetzky. 2005. Paramyxovirus membrane fusion: lessons from the F and HN atomic structures. Virology 344(1):30-7.</ref><ref>Bousse, T. and T. Takimoto. 2006. Mutation at residue 523 creates a second receptor binding site on human parainfluenza virus type 1 hemagglutinin-neuraminidase protein. J Virol 80(18):9009-16.</ref><ref>Porotto, M., M. Fornabaio, G. Kellogg, and A. Moscona. 2007. A second receptor binding site on the human parainfluenza 3 hemagglutinin-neuraminidase contributes to activation of the fusion mechanism. J Virol 81(7):3216-3228.</ref>. Interestingly for NDV HN, functional analysis of the two sites indicated that engagement of the first site activates the second <ref>Porotto, M., M. Fornabaio, O. Greengard, M.T. Murrell, G.E. Kellogg, et al. 2006. Paramyxovirus receptor-binding molecules: engagement of one site on the hemagglutinin-neuraminidase protein modulates activity at the second site. J Virol 80(3):1204-13.</ref><ref>Ryan, C., V. Zaitsev, D.J. Tindal, J.C. Dyason, R.J. Thomson, et al. 2006. Structural analysis of a designed inhibitor complexed with the hemagglutinin-neuraminidase of Newcastle disease virus. Glycoconj J 23(1-2):135-41.</ref>. Further studies on the relationship between the sialic acid binding and cleavage activity of wildtype and mutant HPIV HNs are ongoing among CFG PIs. A region next to the transmembrane domain of HN (stalk region) is still elusive to crystal determination, however several studies showed the importance of this domain in fusion promotion <ref>Melanson, V.R. and R.M. Iorio. 2004. Amino acid substitutions in the F-specific domain in the stalk of the newcastle disease virus HN protein modulate fusion and interfere with its interaction with the F protein. J Virol 78(23):13053-61.</ref><ref>Melanson, V.R. and R.M. Iorio. 2006. Addition of N-glycans in the stalk of the Newcastle disease virus HN protein blocks its interaction with the F protein and prevents fusion. J Virol 80(2):623-33.</ref><ref>Porotto, M., M. Murrell, O. Greengard, and A. Moscona. 2003. Triggering of human parainfluenza virus 3 fusion protein(F) by the hemagglutinin-neuraminidase (HN): an HN mutation diminishing the rate of F activation and fusion. J Virol 77(6):3647-3654.</ref><ref>Bishop, K.A., A.C. Hickey, D. Khetawat, J.R. Patch, K.N. Bossart, et al. 2008. Residues in the stalk domain of the hendra virus g glycoprotein modulate conformational changes associated with receptor binding. J Virol 82(22):11398-409.</ref>.

To further emphasize the importance of understanding GBP paradigms, CFG PIs have shown that HPIV3 infection in cultured monolayer cells greatly differs from infection in human airway epithelial (HAE) cell cultures or in animal models <ref>Zhang, L., M.E. Peeples, R.C. Boucher, P.L. Collins, and R.J. Pickles. 2002. Respiratory syncytial virus infection of human airway epithelial cells is polarized, specific to ciliated cells, and without obvious cytopathology. J Virol 76(11):5654-66.</ref><ref>Mellow, T.E., P.C. Murphy, J.L. Carson, T.L. Noah, L. Zhang, et al. 2004. The effect of respiratory synctial virus on chemokine release by differentiated airway epithelium. Exp Lung Res 30(1):43-57.</ref><ref>Zhang, L., A. Bukreyev, C.I. Thompson, B. Watson, M.E. Peeples, et al. 2005. Infection of ciliated cells by human parainfluenza virus type 3 in an in vitro model of human airway epithelium. J Virol 79(2):1113-24.</ref><ref>Thompson, C.I., W.S. Barclay, M.C. Zambon, and R.J. Pickles. 2006. Infection of human airway epithelium by human and avian strains of influenza A virus. J Virol 80(16):8060-8.</ref>. HPIV3 with a single amino acid mutation in the HN glycoprotein with better than wildtype growth in cell culture had a disadvantage in an ex vivo or in vivo system, revealing a gap in our understanding of the biology of these viruses in their natural host <ref>Palermo, L., M. Porotto, C. Yokoyama, S. Palmer, B. Mungall, et al. 2009. Human parainfluenza virus infection of the airway epithelium: the viral hemagglutinin-neuraminidase regulates fusion protein activation and modulates infectivity. J Virol 83(13):6900-6908.</ref>. This suggests that even slight variations in receptor types may influence HPIV infectivity. Recently a series of studies using glycoarray analysis started to navigate the complexity of the interaction between these viruses and glycomolecules <ref>Amonsen, M., D.F. Smith, R.D. Cummings, and G.M. Air. 2007. Human parainfluenza viruses hPIV1 and hPIV3 bind oligosaccharides with alpha2-3-linked sialic acids that are distinct from those bound by H5 avian influenza virus hemagglutinin. J Virol 81(15):8341-5.</ref>. The three functions of HN depend upon interaction with glycomolecules, therefore understanding whether glycomolecules are preferentially bound, cleave, or activate the fusion process will unravel the biology of these viruses and will help in developing targeted antivirals.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
CFG Participating Investigators (PIs) contributing to the understanding of parainfluenza virus type 3 HN include: Gillian Air, Theodore Jardetsky, Matteo Porotto, Charles Russell

== Progress toward understanding this GBP paradigm ==

=== Carbohydrate ligands ===

Parainfluenza virus type 3 hemagglutinin-neuraminidase binds sialylated glycans. The sialic acid is linked α2-3 to galactose. The minimal binding motif is a pentasaccharide if there are no modifications, but smaller units bind if there is sulfation or fucosylation, as shown in the figure below <ref>Amonsen, M., D.F. Smith, R.D. Cummings, and G.M. Air. 2007. Human parainfluenza viruses hPIV1 and hPIV3 bind oligosaccharides with alpha2-3-linked sialic acids that are distinct from those bound by H5 avian influenza virus hemagglutinin. J Virol 81(15):8341-5.</ref>
 [[File: PIV3glycans.png]]

=== Cellular expression of GBP and ligands ===

Parainfluenza virus type 3 hemagglutinin-neuraminidase is expressed by HPIV paramyxoviruses that bind to sialic acid-containing receptor molecules on the surface of host lung cells.

=== Biosynthesis of ligands ===
The parainfluenza viruses type 3 ligands are typical of complex N-linked glycans. The sialyltransferases that generate the PIV3 receptors are [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_624&sideMenu=true&pageType=general ST3GalIII], [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_625&sideMenu=true&pageType=general ST3GalIV], [http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_627&sideMenu=true&pageType=general ST3GalVI] along with fucosyl transferases that generate Sialyl-Lewis x.
 

=== Structure ===
The crystal structure of a hPIV3 HN has been determined in dimer form <ref>Lawrence, M.C., N.A. Borg, V.A. Streltsov, P.A. Pilling, V.C. Epa, et al. 2004. Structure of the Haemagglutinin-neuraminidase from Human Parainfluenza Virus Type III. J Mol Biol 335(5):1343-57.</ref> and serves as the model for glycan binding and neuraminidase studies.
 
The subunits are colored green and blue. A molecule of inhibitor 2-deoxy-2,3-dehydro-N-acetyl-neuraminic acid is bound to the active site of each subunit (stick model: C, O and N atoms are gray, red and blue respectively). The figure was made using PyMol (Delano Scientific) from PDB file 1V3D.
 
[[file: 1V3D.png]]
 

=== Biological roles of GBP-ligand interaction ===
hPIV HN plays important roles in several distinct steps associated with viral entry, which causes human respiratory infections. For the parainfluenza viruses as well as other paramyxoviruses that utilize hemagglutinin-neuraminidases, the HN protein carries out three different activities in the process of viral entry and release: (1) The first step in infection by human parainfluenza virus is binding to the lung cell surface via interaction of HN with sialic acid-containing receptor molecules on the cell surface.<ref name="Suzuki2001"/><ref name="Moscona2010"/> (2) HN is also essential for activating the fusion protein to mediate merger of the viral envelope with the host cell membrane.<ref name="Lamb1993"/><ref name="Iorio2009"/> (3) Finally, the neuraminidase activity of HN is required for release of the virus from cells.
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=parainfluenza&maxresults=20 CFG database search results for "parainfluenza"].

=== Glycan profiling ===
Receptors for hPIV3 are located in the human respiratory tract. Glycan profiling of human lung tissue has been carried out by the CFG Core C [http://www.functionalglycomics.org/glycomics/publicdata/glycoprofiling-new.jsp].
 

=== Glycogene microarray ===
hPIV HN is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
No experiments have been published using glycosyltransferase knockout mice.
 

=== Glycan array ===
There have been many resource requests for glycan array screening of paramyxovirus hemagglutinin-neuraminidase (for example, click [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_2490 here]). To see all glycan array results for parainfluenza hemagglutinin-neuraminidase, click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=parainfluenza&cat=coreh here].

== Related GBPs ==
* Other paramyxovirus HNs: some appear to have one site that carries out both activities; others appear to have separate sites. For glycan array results of other paramyxovirus HNs, click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=paramyxovirus&cat=coreh here].
* Human parainfluenza types 1, 2, 4 and 5
* Newcastle Disease virus
* Mumps virus

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Gillian Air, James Paulson, Matteo Porotto

[[Category:Introduction]]

File:F17G Igfold v2.jpg

2011-04-15T08:34:56Z

Kurt Drickamer:

CD22

2011-04-15T08:25:10Z

Kurt Drickamer: /* Glycan profiling */

CD22 is predominantly expressed on B cells and is well documented as a regulator of B cell receptor (BCR) signaling<ref name="Crocker 2007">Crocker PR, Paulson JC, Varki A. [http://www.ncbi.nlm.nih.gov/pubmed/17380156 Siglecs and their roles in the immune system]. ''Nat Rev Immunol'' 2007 Apr;7(4):255-66. Review.</ref>. It is one of four siglecs that are highly conserved among mammals. This paradigm is unique among the siglecs in that the cytoplasmic domain has six conserved tyrosine motifs, including three immunoreceptor tyrosine inhibitory motifs (ITIM), one ITIM-like motif, and a growth factor receptor bound protein2 (GRB2) motif. These tyrosine motifs are involved in regulation of BCR signaling and also mediate its constitutive clathrin mediated endocytosis, an activity believed to be tied to its regulation of cell signaling. The preferred glycan ligand of CD22 differs significantly in humans and mice<ref name="Crocker 2007"/><ref name="Kimura 2007">Kimura N, Ohmori K, Miyazaki K, Izawa M, Matsuzaki Y, Yasuda Y, Takematsu H, Kozutsumi Y, Moriyama A, Kannagi R. [http://www.ncbi.nlm.nih.gov/pubmed/17728258 Human B-lymphocytes express alpha2-6-sialylated 6-sulfo-N-acetyllactosamine serving as a preferred ligand for CD22/Siglec-2]. J'' Biol Chem''. 2007 Nov 2;282(44):32200-7.</ref><ref name="Blixt 2004">Blixt O, Head S, Mondala T, Scanlan C, Huflejt ME, Alvarez R, Bryan MC, Fazio F, Calarese D, Stevens J, Razi N, Stevens DJ, Skehel JJ, van Die I, Burton DR, Wilson IA, Cummings R, Bovin N, Wong CH, Paulson JC. [http://www.ncbi.nlm.nih.gov/pubmed/15563589 Printed covalent glycan array for ligand profiling of diverse glycan binding proteins]. ''Proc Natl Acad Sci U S A''. 2004 Dec 7;101(49):17033-8.</ref>. While both recognize the sequence Siaa-2-6Galb-1-4GlcNAc expressed abundantly on B cells, murine CD22 prefers Neu5Gc (not found in humans) over Neu5Ac, while human CD22 exhibits highest affinity for sulfated sialoside, Neu5Aca-2-6Galb-1-4[6S]GlcNAc, demonstrating significant evolution of ligand specificity with conservation of function. Although CD22 recognizes ligands on the same cell in ''cis'', it also binds to ligands in ''trans'' if expressed on adjacent contacting cells. A major area of investigation is to understand the relative roles of ''cis'' and ''trans'' ligands in CD22 function.

[[Image:SiglecCD22.jpg|right|alt text]]
== CFG Participating Investigators contributing to the understanding of this paradigm ==

CFG Participating Investigators (PIs) have made major contributions to the understanding of the biology of human and murine CD22. These include: Nicolai Bovin, Paul Crocker, Jamey Marth, David Nemazee, Lars Nitschke, Jim Paulson, Ajit Varki

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about CD22, its carbohydrate ligand(s), and how they interact to mediate cell communication. Further information can be found in the GBP Molecule Page for [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_hum_Itlect_269&sideMenu=no human] and [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_mou_Itlect_194&sideMenu=no mouse] CD22 (aka Siglec-2) in the CFG database.
=== Carbohydrate ligands ===
Although CD22 is highly conserved throughout mammalian species, murine and human CD22 are known to exhibit significant differences in their specificities that appear to have evolved to compensate for changes in the glycan ligands expressed on B cells. While both bind Siaα2-6Gal terminated glycans, murine CD22 prefers NeuGc (NeuGcα2-6Galβ1-4GlcNAc), which is not found in humans. In contrast, human human CD22 recognizes NeuAc and NeuGc with equal affinity. In addition, however, human CD22 exhibits highest affinity for a ligand with sulfate at the 6 position of GlcNAc (NeuAcα2-6Galβ1-4[6S]GlcNAc).<ref name="Crocker 2007"/><ref name="Kimura 2007"/> 9-O-acetylation of sialic acid abrogates binding of CD22, which is thought to regulate the binding of ''cis'' ligands on B cells.
 
=== Cellular expression of GBP and ligands ===
CD22 is primarily expressed on mature B cells and to a lesser extent on memory B cells. However, it is not expressed on pre-B cells and differentiated plasma cells. Like many siglecs, CD22 interacts with endogenous ligands on B cells in ''cis'', and on other cells, such as T cells and bone marrow vessel endothelial cells in ''trans''. Although ''cis'' ligands of tend to mask the CD22 binding site, CD22 is able to interact with ''trans'' ligands on contacting cells (B cells and T cells), and to bind to synthetic multivalent ligands that have sufficient avidity.
 
=== Biosynthesis of ligands ===
The ligands of CD22 are predominately the product of a single sialyltransferase, ST6Gal I. Mice deficient in ST6Gal I express no ligands on B cells resulting in an immuno-deficient phenotype.
 
=== Structure ===
Although the crystal structure of CD22 has not yet been elucidated, structures of other siglecs, including sialoadhesin, siglec-5 and siglec-7 have shed insights into the nature of the ligand binding site of CD22.<ref name="Crocker 2007"/>
 
=== Biological roles of GBP-ligand interaction ===

 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=CD22&maxresults=20 CFG database search results for CD22].

=== Glycan profiling ===
Both murine and human CD22 recognize the sequence Siaα2-6Galβ1-4GlcNAc expressed abundantly on [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=b%20AND%20cells&cat=corec B cells], which have been subjected to glycan profiling by the CFG.
 

=== Glycogene microarray ===

The CFG glycogene microarray has been used to show that ST6Gal I is downregulated [https://www.functionalglycomics.org/glycomics/publicdata/microarray.jsp?resReqId=cfg_rRequest_2 'on T cells] upon activation suggesting that B cell ''trans'' ligands are reduced on activated T cells. Probes for mouse and human CD22 have been included on all four versions of the CFG glycogene array.

=== Knockout mouse lines ===
Mice deficient in [https://www.functionalglycomics.org/static/consortium/resources/resourcecoref16.shtml CD22] and the sialyltransferase, ST6Gal I, responsible for synthesis of its ligands ([https://www.functionalglycomics.org/glycomics/publicdata/phenotyping.jsp ST6Gal I]) distributed by the CFG have been instrumental in understanding the biology of CD22.

=== Glycan array ===
The CFG's glycan array was instrumental in identification of the [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_1792 high affinity ligands of CD22] as sialylated-sulfated glycans.<ref name="Kimura 2007"/><ref name="Blixt 2004"/>

== Related GBPs ==

This paradigm is unique among the siglecs in that the cytoplasmic domain has six conserved tyrosine motifs, including three immunoreceptor tyrosine inhibitory motifs (ITIM), one ITIM-like motif, and a growth factor receptor bound protein2 (GRB2) motif. However, other members of the homologous siglec family have contributed to an understanding of the glycan binding site of CD22, and general principles governing the interaction of CD22 with ''cis'' and ''trans'' ligands.

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Paul Crocker, James Paulson

Galectin-3

2011-04-15T08:03:30Z

Kurt Drickamer: /* Glycan profiling */

Galectin-3...
* is the only member of the chimeric subfamily in mammals
* is a very well-studied glycan-binding protein (GBP)
* has a known crystal structure (C-terminal glycan-binding domain)
* has unique functions intra- and extra-cellularly, due to an unusual N-terminal domain that can participate in protein-protein interactions
* has a unique mode of multimerization
* is the only known anti-apoptotic galectin, and acts through intracellular action<ref>Saegusa J, Hsu DK, Liu W, Kuwabara I, Kuwabara Y, Yu L, Liu FT [http://www.ncbi.nlm.nih.gov/pubmed/18463681 Galectin-3 protects keratinocytes from UVB-induced apoptosis by enhancing AKT activation and suppressing ERK activation.] J Invest Dermatol. 2008 Oct;128(10):2403-11. PubMed PMID: 18463681; PubMed Central PMCID: PMC2768377.</ref>
* null mice have distinct phenotypes, including alterations in inflammatory and wound-healing responses, and cyst formation in disease<ref>Chiu MG, Johnson TM, Woolf AS, Dahm-Vicker EM, Long DA, Guay-Woodford L,
Hillman KA, Bawumia S, Venner K, Hughes RC, Poirier F, Winyard PJ. [http://www.ncbi.nlm.nih.gov/pubmed/17148658 Galectin-3 associates with the primary cilium and modulates cyst growth in congenital polycystic kidney disease.] Am J Pathol. 2006 Dec;169(6):1925-38.</ref>
* has unique functions in innate immune response to microbial pathogens
* has been administered in animal models of disease to assess therapeutic potential
* binds distinct cell surface glycoprotein ligands in lymphocytes compared to galectin-1
* expression is involved in growth modulation<ref>Baptiste TA, James A, Saria M, Ochieng J. [http://www.ncbi.nlm.nih.gov/pubmed/17184769 Mechano-transduction mediated secretion and uptake of galectin-3 in breast carcinoma cells: implications in the extracellular functions of the lectin.] Exp Cell Res. 2007 Feb 15;313(4):652-64. Epub 2006 Nov 16. PubMed PMID: 17184769; PubMed Central PMCID: PMC1885467.</ref>
 
Galectin-3 is the only member of the galectin family with an extended N-terminal region composed of tandem repeats of short amino-acid segments (a total of approximately 120 amino acids) connected to a C-terminal CRD. Like other galectins, galectin-3 lacks a signal sequence required for secretion through the classical secretory pathway, but the protein is released into the extracellular space. 
Galectin-3 can oligomerize in the presence of multivalent carbohydrate ligands and is capable of crosslinking glycans on the cell surface, thereby initiating transmembrane signaling events and affecting various cellular functions (reviewed in <ref name="Liu 2005">Liu FT, Rabinovich GA. [http://www.ncbi.nlm.nih.gov/pubmed/15630413 Galectins as modulators of tumour progression.] Nat Rev Cancer. 2005 Jan;5(1):29-41. Review. PubMed PMID: 15630413.</ref><ref>Almkvist J, Karlsson A. [http://www.ncbi.nlm.nih.gov/pubmed/14758082 Galectins as inflammatory mediators.] Glycoconj J.
2004;19(7-9):575-81. Review. PubMed PMID: 14758082.</ref><ref>Ochieng J, Furtak V, Lukyanov P. [http://www.ncbi.nlm.nih.gov/pubmed/14758076 Extracellular functions of galectin-3.] Glycoconj J. 2004;19(7-9):527-35. Review. PubMed PMID: 14758076.</ref>). This ability to self-associate is dependent on the N-terminal region of the protein.
 Compared to other galectins, intracellular functions of galectin-3 have been more extensively documented (reviewed in <ref>Liu FT, Patterson RJ, Wang JL. [http://www.ncbi.nlm.nih.gov/pubmed/12223274 Intracellular functions of galectins.] Biochim Biophys Acta. 2002 Sep 19;1572(2-3):263-73. Review. PubMed PMID: 12223274.</ref>). In some cases, intracellular proteins with which the protein interacts and which possibly mediate these functions have been identified. Galectin-3 can be phosphorylated at serines 6 & 12<ref>Huflejt ME, Turck CW, Lindstedt R, Barondes SH, Leffler H. [http://www.ncbi.nlm.nih.gov/pubmed/8253806 L-29, a soluble lactose-binding lectin, is phosphorylated on serine 6 and serine 12 in vivo and by casein kinase I.] J Biol Chem. 1993 Dec 15;268(35):26712-8. PubMed PMID:8253806.</ref>, and tyrosines 79 & 118 by c-Abl<ref>Balan V, Nangia-Makker P, Jang YS, Wang Y, Raz A. [http://www.ncbi.nlm.nih.gov/pubmed/20600357 Galectin-3: A novel substrate for c-Abl kinase.] Biochim Biophys Acta. 2010 Jun 30. PubMed PMID: 20600357</ref><ref>Li X, Ma Q, Wang J, Liu X, Yang Y, Zhao H, Wang Y, Jin Y, Zeng J, Li J, Song L, Li X, Li P, Qian X, Cao C. [http://www.ncbi.nlm.nih.gov/pubmed/20150913 c-Abl and Arg tyrosine kinases regulate lysosomal degradation of the oncoprotein Galectin-3.] Cell Death Differ. 2010 Aug;17(8):1277-87. Epub 2010 Feb 12. PubMed PMID: 20150913.</ref>.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
CFG Participating Investigators (PIs) contributing to the understanding of Galectin-3 include: Pablo Argüeso, Linda Baum, Susan Bellis, Roger Chammas, Richard Cummings, James Dennis, Margaret, Huflejt, Fu-Tong Liu, Joshiah Ochieng, Noorjahan Panjawani, Mauro Perretti, Avram Raz, James Rini, Maria Roque-Barreira, Sachiko Sato, Tariq Sethi, Irma van Die, Gerardo Vasta, John Wang, Paul Winyard

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about Galectin-3, its carbohydrate ligand(s), and how they interact to mediate cell communication. Further information can be found in the GBP Molecule Pages for [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_hum_Stlect_00118&sideMenu=no human] and [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_1306&sideMenu=no mouse] Galectin-3 in the CFG database.
=== Carbohydrate ligands ===

 
=== Cellular expression of GBP and ligands===
Galectin-3 is constitutively expressed in epithelial and myeloid cells, and regulated by processes that include cell proliferation, inflammation, and tumor initiation and progression[cite]. Gene expression in various cells and tissues have been performed with CFG [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=galectin-3&cat=coree Core IgE].
 
=== Biosynthesis of ligands ===
The immunomodulatory activity of galectin 3 is mediated by binding to poly N-acetyllactosamine chains attached to the T cell receptor, resulting in a decrease in the lateral mobility of the receptor, which suppresses its activation. Attachment of the poly N-acetyllactosamine chains is dependent on the establishment of a 1-6 branch on the core oligosaccharide, through the action of GlcNAc transferase V (Mgat5) ([http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_553&sideMenu=true&pageType=general Human][http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_mou_597&sideMenu=true&pageType=general Mouse]). Extension of the chain requires the action of UDP-GlcNAc:βGal β-1,3-N-acetylglucosaminyltransferase 1 ([http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_536&sideMenu=true&pageType=general Human][http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_mou_571&sideMenu=true&pageType=general Mouse]) and galactosyltransferase and β1-4galatosyltransferase 1 ([http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_hum_436&sideMenu=true&pageType=general Human][http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/viewGlycoEnzyme.jsp?gbpId=gt_mou_460&sideMenu=true&pageType=general Mouse]).
 

=== Structure ===
The structures of the CRD of galectin-3 from X-ray crystallographic<ref>Seetharaman, J., Kanigsberg, A., Slaaby, R., Leffler, H., Barondes, S.H., and Rini, J.M. [http://www.ncbi.nlm.nih.gov/pubmed/9582341 X-ray crystal structure of the human galectin-3 carbohydrate recognition domain at 2.1 angstrom resolution.] J. Biol. Chem. 1998; 273: 13047–13052. PMID: 9582341.</ref> and NMR<ref>Umemoto K, Leffler H, Venot A, Valafar H, Prestegard JH. [http://www.ncbi.nlm.nih.gov/pubmed/12667058 Conformational differences in liganded and unliganded states of Galectin-3.] Biochem. 2003; 8;42(13):3688-3695. PMID: 12667058.</ref> analyses have been described. The proline-rich N-terminal domain is required for oligomerization of galectin-3<ref>Hsu DK, Zuberi RI, Liu FT. [http://www.ncbi.nlm.nih.gov/pubmed/1629216 Biochemical and biophysical characterization of human recombinant IgE-binding protein, an S-type animal lectin.] J Biol Chem. 1992; 267(20):14167-14174. PMID: 1629216.</ref> and demonstrates significant interaction with the CRD as initially suggested by observations that a monoclonal antibody recognizing an epitope in the N-terminus was capable of inhibiting glycan binding in the C-terminal CRD<ref>Liu FT, Hsu DK, Zuberi RI, Hill PN, Shenhav A, Kuwabara I, Chen SS. [http://www.ncbi.nlm.nih.gov/pubmed/8634249 Modulation of functional properties of galectin-3 by monoclonal antibodies binding to the non-lectin domains.] Biochemistry. 1996; 35(19):6073-6079. PMID: 8634249.</ref>, and revealed by NMR and EM studies<ref>Birdsall B, Feeney J, Burdett ID, Bawumia S, Barboni EA, Hughes RC. [http://www.ncbi.nlm.nih.gov/pubmed/11294654 NMR solution studies of hamster galectin-3 and electron microscopic visualization of surface-adsorbed complexes: evidence for interactions between the N- and C-terminal domains.] Biochem. 2001; 40:4859-4866. PMID: 11294654.</ref>.
 
=== Biological roles of GBP-ligand interaction ===

'''Regulation of cellular responses.''' 
Galectin-3 induces various kinds of biological responses in a variety cell types in vitro by engaging glycoproteins or glycolipids on the cell surfaces (reviewed in <ref>Rabinovich GA, Liu FT, Hirashima M, Anderson A. An emerging role for galectins in tuning the immune response: lessons from experimental models of inflammatory disease, autoimmunity and cancer. Scand J Immunol. 2007 Aug-Sep;66(2-3):143-58. Review. PubMed PMID:17635792 http://www.ncbi.nlm.nih.gov/pubmed/17635792</ref><ref>Liu FT. [http://www.ncbi.nlm.nih.gov/pubmed/15775687 Regulatory roles of galectins in the immune response.] Int Arch Allergy Immunol. 2005 Apr;136(4):385-400. Review. PubMed PMID: 15775687.</ref>). 

Galectin-3 can form lattices with selected cell surface glycans, in which galectin-3 oligomers bind to glycans on different glycoproteins displayed on the cell surface. Through this mechanism, galectin-3 modulates the properties and responses of the glycoproteins, such as their lateral mobility on the cell surface, rate of endocytosis, and transmission of signals at the cell surface (reviewed in <ref>Lajoie P, Goetz JG, Dennis JW, Nabi IR. [http://www.ncbi.nlm.nih.gov/pubmed/19398762 Lattices, rafts, and scaffolds: domainregulation of receptor signaling at the plasma membrane.] J Cell Biol. 2009 May 4;185(3):381-5. Epub 2009 Apr 27. Review. PubMed PMID: 19398762; PubMed Central PMCID: PMC2700393.</ref><ref>Grigorian A, Torossian S, Demetriou M. [http://www.ncbi.nlm.nih.gov/pubmed/19594640 T-cell growth, cell surface organization, and the galectin-glycoprotein lattice.] Immunol Rev. 2009 Jul;230(1):232-46. Review. PubMed PMID: 19594640.</ref><ref>Dennis JW, Nabi IR, Demetriou M. [http://www.ncbi.nlm.nih.gov/pubmed/20064370 Metabolism, cell surface organization, and disease.] Cell. 2009 Dec 24;139(7):1229-41. Review. PubMed PMID: 20064370.</ref>). 

Endogenous galectin-3 regulates cellular responses by functioning inside the cells, including pre-mRNA splicing, where galectin-3 functions as a component of spliceosomes<ref>Haudek KC, Spronk KJ, Voss PG, Patterson RJ, Wang JL, Arnoys EJ. [http://www.ncbi.nlm.nih.gov/pubmed/19616076 Dynamics of galectin-3 in the nucleus and cytoplasm.] Biochim Biophys Acta. 2010 Feb;1800(2):181-9. Epub 2009 Jul 16. Review. PubMed PMID: 19616076; PubMed Central PMCID: PMC2815258.</ref>, and regulation of expression of certain genes, including those for cyclin D1, thyroid-specific TTF-1 transcription factor, MUC2 mucin, and c-Jun N-terminal kinase (reviewed in <ref>Nakahara S, Raz A. [http://www.ncbi.nlm.nih.gov/pubmed/17726578 Regulation of cancer-related gene expression by galectin-3 and the molecular mechanism of its nuclear import pathway.] Cancer Metastasis Rev. 2007 Dec;26(3-4):605-10. Review. PubMed PMID: 17726578.</ref><ref>Yang RY, Rabinovich GA, Liu FT. [http://www.ncbi.nlm.nih.gov/pubmed/18549522 Galectins: structure, function and therapeutic potential.] Expert Rev Mol Med. 2008 Jun 13;10:e17. Review. PubMed PMID: 18549522.</ref>). 

Endogenous Galectin-3 inhibits apoptosis in various cell types by functioning inside the cells (reviewed in <ref>Hsu DK, Yang RY, Liu FT. [http://www.ncbi.nlm.nih.gov/pubmed/17132510 Galectins in apoptosis.] Methods Enzymol.2006;417:256-73. Review. PubMed PMID: 17132510.</ref><ref>Hsu DK, Liu FT. [http://www.ncbi.nlm.nih.gov/pubmed/14758074 Regulation of cellular homeostasis by galectins.] Glycoconj J. 2004;19(7-9):507-15. Review. PubMed PMID: 14758074.</ref>). 

Endogenous Galectin-3 controls intracellular trafficking of glycoproteins<ref>Delacour D, Koch A, Jacob R. [http://www.ncbi.nlm.nih.gov/pubmed/19650851 The role of galectins in protein trafficking.] Traffic. 2009 Oct;10(10):1405-13. Epub 2009 Jun 26. Review. PubMed PMID:19650851.</ref><ref>Stechly L, Morelle W, Dessein AF, André S, Grard G, Trinel D, Dejonghe MJ,Leteurtre E, Drobecq H, Trugnan G, Gabius HJ, Huet G. [http://www.ncbi.nlm.nih.gov/pubmed/19192249 Galectin-4-regulated delivery of glycoproteins to the brush border membrane of enterocyte-like cells.] Traffic. 2009 Apr;10(4):438-50. Epub 2009 Jan 24. PubMed PMID: 19192249.</ref>, which may be linked to its ability to translocate into the lumen of transport vesicles. Intracellular galectin-3 is associated with centrosomes in epithelial cells transiently during the process of epithelial polarization and may thus regulate epithelial polarization in enterocytes<ref>Delacour D, Koch A, Ackermann W, Eude-Le Parco I, Elsässer HP, Poirier F,Jacob R. [http://www.ncbi.nlm.nih.gov/pubmed/18211959 Loss of galectin-3 impairs membrane polarisation of mouse enterocytes in vivo.] J Cell Sci. 2008 Feb 15;121(Pt 4):458-65. Epub 2008 Jan 22. PubMed PMID:18211959.</ref><ref>Koch A, Poirier F, Jacob R, Delacour D. [http://www.ncbi.nlm.nih.gov/pubmed/19923323 Galectin-3, a novel centrosome-associated protein, required for epithelial morphogenesis.] Mol Biol Cell. 2010 Jan;21(2):219-31. Epub 2009 Nov 18. PubMed PMID: 19923323; PubMed Central PMCID: PMC2808235.</ref>. Galectin-3 contributes to maintenance of the barrier function of ocular surface epithelial cells<ref>Argüeso P, Guzman-Aranguez A, Mantelli F, Cao Z, Ricciuto J, Panjwani N. [http://www.ncbi.nlm.nih.gov/pubmed/19556244 Association of cell surface mucins with galectin-3 contributes to the ocular surface epithelial barrier.] J Biol Chem. 2009 Aug 21;284(34):23037-45. Epub 2009 Jun 25. PubMed PMID: 19556244; PubMed Central PMCID: PMC2755710.</ref>. 

'''Immunity and inflammation.''' 

''Functions demonstrated in vitro.'' 
T and B cells 
Endogenous galectin-3
:* regulates differentiation of B cells into plasma cells and memory B cells<ref>Acosta-Rodríguez EV, Montes CL, Motrán CC, Zuniga EI, Liu FT, Rabinovich GA, Gruppi A. [http://www.ncbi.nlm.nih.gov/pubmed/14688359 Galectin-3 mediates IL-4-induced survival and differentiation of B cells: functional cross-talk and implications during Trypanosoma cruzi infection.] J Immunol. 2004 Jan 1;172(1):493-502. PubMed PMID: 14688359.</ref>
:* is anti-apoptotic in B cell lines<ref>Hoyer KK, Pang M, Gui D, Shintaku IP, Kuwabara I, Liu FT, Said JW, Baum LG, Teitell MA. [http://www.ncbi.nlm.nih.gov/pubmed/14982843 An anti-apoptotic role for galectin-3 in diffuse large B-cell lymphomas.] Am J Pathol. 2004 Mar;164(3):893-902. PubMed PMID: 14982843; PubMed Central PMCID: PMC1614710.</ref> 

In T cells, purified galectin-3
:* induces IL-2 production<ref>Hsu DK, Hammes SR, Kuwabara I, Greene WC, Liu FT. [http://www.ncbi.nlm.nih.gov/pubmed/8623933 Human T lymphotropic virus-I infection of human T lymphocytes induces expression of the beta-galactoside-binding lectin, galectin-3.] Am J Pathol. 1996
May;148(5):1661-70. PubMed PMID: 8623933; PubMed Central PMCID: PMC1861566.</ref> and calcium influx<ref>Dong S, Hughes RC. [http://www.ncbi.nlm.nih.gov/pubmed/8898087 Galectin-3 stimulates uptake of extracellular Ca2+ in human Jurkat T-cells.] FEBS Lett. 1996 Oct 21;395(2-3):165-9. PubMed PMID: 8898087.</ref> in Jurkat T cells
:* induces apoptosis in human T leukemic cell lines, human peripheral blood mononuclear cells, and mouse activated T cells<ref>Fukumori T, Takenaka Y, Yoshii T, Kim HR, Hogan V, Inohara H, Kagawa S, Raz A. [http://www.ncbi.nlm.nih.gov/pubmed/14678989 CD29 and CD7 mediate galectin-3-induced type II T-cell apoptosis.] Cancer Res. 2003 Dec 1;63(23):8302-11. PubMed PMID: 14678989.</ref><ref name="Stillman 2006">Stillman BN, Hsu DK, Pang M, Brewer CF, Johnson P, Liu FT, Baum LG. [http://www.ncbi.nlm.nih.gov/pubmed/16393961 Galectin-3 and galectin-1 bind distinct cell surface glycoprotein receptors to induce T cell death.] J Immunol. 2006 Jan 15;176(2):778-89. PubMed PMID: 16393961.</ref>, normal human T cells<ref name="Stowell 2008">Stowell SR, Qian Y, Karmakar S, Koyama NS, Dias-Baruffi M, Leffler H, McEver RP, Cummings RD. [http://www.ncbi.nlm.nih.gov/pubmed/18292532 Differential roles of galectin-1 and galectin-3 in regulating leukocyte viability and cytokine secretion.] J Immunol. 2008 Mar 1;180(5):3091-102. PubMed PMID: 18292532.</ref>, and a human tumor infiltrating T cell line<ref>Peng W, Wang HY, Miyahara Y, Peng G, Wang RF. [http://www.ncbi.nlm.nih.gov/pubmed/18757439 Tumor-associated galectin-3 modulates the function of tumor-reactive T cells.] Cancer Res. 2008 Sep 1;68(17):7228-36. PubMed PMID: 18757439.</ref>. In some T cell lines, such as MOLT-4 cells, galectin-3 induces phosphatidylserine exposure, an early event in apoptosis, but not cell death<ref name="Stowell 2008"/>
:* induces apoptosis in both Th1 and Th2 cells<ref>Toscano MA, Bianco GA, Ilarregui JM, Croci DO, Correale J, Hernandez JD, Zwirner NW, Poirier F, Riley EM, Baum LG, Rabinovich GA. [http://www.ncbi.nlm.nih.gov/pubmed/17589510 Differential glycosylation of TH1, TH2 and TH-17 effector cells selectively regulates susceptibility to cell death.] Nat Immunol. 2007 Aug;8(8):825-34. Epub 2007 Jun 24. PubMed PMID: 17589510.</ref>
:* induces apoptosis in CD4-CD8- human thymocytes<ref name="Stillman 2006"/>
:* attenuates interaction of thymocytes with thymic nurse cells<ref>Silva-Monteiro E, Reis Lorenzato L, Kenji Nihei O, Junqueira M, Rabinovich GA, Hsu DK, Liu FT, Savino W, Chammas R, Villa-Verde DM. [http://www.ncbi.nlm.nih.gov/pubmed/17255323 Altered expression of galectin-3 induces cortical thymocyte depletion and premature exit of immature thymocytes during Trypanosoma cruzi infection.] Am J Pathol. 2007 Feb;170(2):546-56. PubMed PMID: 17255323; PubMed Central PMCID: PMC1851869.</ref> 

Endogenous Galectin-3 has anti-apoptotic activity in the human T cell line Jurkat<ref>Yang RY, Hsu DK, Liu FT. [http://www.ncbi.nlm.nih.gov/pubmed/8692888 Expression of galectin-3 modulates T-cell growth and
apoptosis.] Proc Natl Acad Sci U S A. 1996 Jun 25;93(13):6737-42. PubMed PMID:8692888; PubMed Central PMCID: PMC39096.</ref>. 

Galectin-3 has also been documented in the following T cell functions:
:* binds to Mgat5-modified T cell receptor (TCR) and suppresses T cell activation induced by TCR engagement; this is associated with a decrease in lateral mobility of TCR<ref>Demetriou M, Granovsky M, Quaggin S, Dennis JW. [http://www.ncbi.nlm.nih.gov/pubmed/11217864 Negative regulation of T-cell activation and autoimmunity by Mgat5 N-glycosylation.] Nature. 2001 Feb 8;409(6821):733-9. PubMed PMID: 11217864.</ref>
:* attenuates association of CD8 and TCR on CD8+ tumor-infiltrating lymphocytes, thus causing anergy<ref>Demotte N, Stroobant V, Courtoy PJ, Van Der Smissen P, Colau D, Luescher IF, Hivroz C, Nicaise J, Squifflet JL, Mourad M, Godelaine D, Boon T, van der Bruggen P. [http://www.ncbi.nlm.nih.gov/pubmed/18342010 Restoring the association of the T cell receptor with CD8 reverses anergy in human tumor-infiltrating lymphocytes.] Immunity. 2008 Mar;28(3):414-24. PubMed PMID: 18342010.</ref>
:* negatively regulates TCR-mediated CD4+ T cell activation at the immunological synapse, by intracellular action<ref>Chen HY, Fermin A, Vardhana S, Weng IC, Lo KF, Chang EY, Maverakis E, Yang RY, Hsu DK, Dustin ML, Liu FT. [http://www.ncbi.nlm.nih.gov/pubmed/19706535 Galectin-3 negatively regulates TCR-mediated CD4+ T-cell activation at the immunological synapse.] Proc Natl Acad Sci U S A. 2009 Aug 25;106(34):14496-501. Epub 2009 Aug 12. PubMed PMID: 19706535; PubMed Central PMCID: PMC2732795.</ref>

Dendritic cells 
Endogenous Galectin-3
:* suppresses the production of IL-12 by dendritic cells<ref name="Bernardes 2006">Bernardes ES, Silva NM, Ruas LP, Mineo JR, Loyola AM, Hsu DK, Liu FT, Chammas R, Roque-Barreira MC. [http://www.ncbi.nlm.nih.gov/pubmed/16723706 Toxoplasma gondii infection reveals a novel regulatory role for galectin-3 in the interface of innate and adaptive immunity.] Am J Pathol. 2006 Jun;168(6):1910-20. PubMed PMID: 16723706; PubMed Central PMCID: PMC1606628.</ref> and may suppress Th1 responses<ref name="Saegusa 2009">Saegusa J, Hsu DK, Chen HY, Yu L, Fermin A, Fung MA, Liu FT. [http://www.ncbi.nlm.nih.gov/pubmed/19179612 Galectin-3 is critical for the development of the allergic inflammatory response in a mouse model of atopic dermatitis.] Am J Pathol. 2009 Mar;174(3):922-31. Epub 2009 Jan 29. PubMed PMID: 19179612; PubMed Central PMCID: PMC2665752.</ref>
:* promotes Th2 polarization in the setting of antigen presentation to T cells by dendritic cells<ref name="Saegusa 2009"/>. Another study suggests that galectin-3 suppresses the antigen-presenting function of dendritic cells<ref name="Breuilh 2007">Breuilh L, Vanhoutte F, Fontaine J, van Stijn CM, Tillie-Leblond I, Capron M, Faveeuw C, Jouault T, van Die I, Gosset P, Trottein F. [http://www.ncbi.nlm.nih.gov/pubmed/17785480 Galectin-3 modulates immune and inflammatory responses during helminthic infection: impact of galectin-3 deficiency on the functions of dendritic cells.] Infect Immun. 2007 Nov;75(11):5148-57. Epub 2007 Sep 4. PubMed PMID: 17785480; PubMed Central PMCID: PMC2168304.</ref>)
:* promotes dendritic cell trafficking by functioning intracellularly<ref name="Hsu 2009">Hsu DK, Chernyavsky AI, Chen HY, Yu L, Grando SA, Liu FT. [http://www.ncbi.nlm.nih.gov/pubmed/18843294 Endogenous galectin-3 is localized in membrane lipid rafts and regulates migration of dendritic cells.] J Invest Dermatol. 2009 Mar;129(3):573-83. Epub 2008 Oct 9. PubMed PMID: 18843294; PubMed Central PMCID: PMC2645233.</ref>
Galectin-3 promotes adhesion of mouse dendritic cells<ref>[Vray B, Camby I, Vercruysse V, Mijatovic T, Bovin NV, Ricciardi-Castagnoli P,
Kaltner H, Salmon I, Gabius HJ, Kiss R. [http://www.ncbi.nlm.nih.gov/pubmed/15044384 Up-regulation of galectin-3 and its ligands by Trypanosoma cruzi infection with modulation of adhesion and migration of murine dendritic cells.] Glycobiology. 2004 Jul;14(7):647-57. Epub 2004 Mar 24.PubMed PMID: 15044384</ref>. 

Neutrophils 
Galectin-3 acts on these cells in the following manner:
:* induces oxidative burst<ref>Yamaoka A, Kuwabara I, Frigeri LG, Liu FT. [http://www.ncbi.nlm.nih.gov/pubmed/7897228 A human lectin, galectin-3 (epsilon bp/Mac-2), stimulates superoxide production by neutrophils.] J Immunol. 1995 Apr 1;154(7):3479-87. PubMed PMID: 7897228.</ref><ref>Karlsson A, Follin P, Leffler H, Dahlgren C. [http://www.ncbi.nlm.nih.gov/pubmed/9558402 Galectin-3 activates the NADPH-oxidase in exudated but not peripheral blood neutrophils.] Blood. 1998 May 1;91(9):3430-8. PubMed PMID: 9558402.</ref><ref>Almkvist J, Fäldt J, Dahlgren C, Leffler H, Karlsson A. [http://www.ncbi.nlm.nih.gov/pubmed/11159975 Lipopolysaccharide-induced gelatinase granule mobilization primes neutrophils for activation by galectin-3 and formylmethionyl-Leu-Phe.] Infect Immun. 2001 Feb;69(2):832-7. PubMed PMID: 11159975; PubMed Central PMCID: PMC97959.</ref> and L-selectin shedding as well as IL-8 production<ref name="Farnworth 2008">Farnworth SL, Henderson NC, Mackinnon AC, Atkinson KM, Wilkinson T, Dhaliwal K, Hayashi K, Simpson AJ, Rossi AG, Haslett C, Sethi T. [http://www.ncbi.nlm.nih.gov/pubmed/18202191 Galectin-3 reduces the severity of pneumococcal pneumonia by augmenting neutrophil function.] Am J Pathol. 2008 Feb;172(2):395-405. Epub 2008 Jan 17. PubMed PMID: 18202191; PubMed Central PMCID: PMC2312371.</ref>
:* promotes neutrophil adhesion to the extracellular protein laminin<ref>Kuwabara I, Liu FT. [http://www.ncbi.nlm.nih.gov/pubmed/8621934 Galectin-3 promotes adhesion of human neutrophils to laminin.] J Immunol. 1996 May 15;156(10):3939-44. PubMed PMID: 8621934.</ref> and endothelial cells<ref>Sato S, Ouellet N, Pelletier I, Simard M, Rancourt A, Bergeron MG. [http://www.ncbi.nlm.nih.gov/pubmed/11823514 Role of galectin-3 as an adhesion molecule for neutrophil extravasation during streptococcal pneumonia.] J Immunol. 2002 Feb 15;168(4):1813-22. PubMed PMID: 11823514.</ref>
:* induces phosphatidylserine exposure in the absence of cell death<ref name="Stowell 2008"/>, and induces apoptosis<ref>Fernández GC, Ilarregui JM, Rubel CJ, Toscano MA, Gómez SA, Beigier Bompadre M, Isturiz MA, Rabinovich GA, Palermo MS. [http://www.ncbi.nlm.nih.gov/pubmed/15604089 Galectin-3 and soluble fibrinogen act in concert to modulate neutrophil activation and survival: involvement of alternative MAPK pathways.] Glycobiology. 2005 May;15(5):519-27. Epub 2004 Dec 15. PubMed PMID: 15604089.</ref>
Endogenous galectin-3 protects neutrophils from apoptosis<ref name="Farnworth 2008"/>. 

Macrophages 
Endogenous galectin-3
:* is anti-apoptotic in macrophages treated with LPS and IFN-γ<ref name="Colnot 1998">Colnot C, Ripoche MA, Milon G, Montagutelli X, Crocker PR, Poirier F. [http://www.ncbi.nlm.nih.gov/pubmed/9767409 Maintenance of granulocyte numbers during acute peritonitis is defective in galectin-3-null mutant mice.] Immunology. 1998 Jul;94(3):290-6. PubMed PMID: 9767409; PubMed Central PMCID: PMC1364244.</ref>. It plays a critical role in the phagocytic function of macrophages in ingesting opsonized sheep red blood cells and apoptotic thymocytes. 
:* plays a critical role in alternative macrophage activation<ref>MacKinnon AC, Farnworth SL, Hodkinson PS, Henderson NC, Atkinson KM, Leffler H, Nilsson UJ, Haslett C, Forbes SJ, Sethi T. [http://www.ncbi.nlm.nih.gov/pubmed/18250477 Regulation of alternative macrophage activation by galectin-3.] J Immunol. 2008 Feb 15;180(4):2650-8. PubMed PMID: 18250477.</ref>

Recombinant galectin-3
:* triggers human peripheral blood monocytes to produce superoxide anion<ref>Liu FT, Hsu DK, Zuberi RI, Kuwabara I, Chi EY, Henderson WR Jr. [http://www.ncbi.nlm.nih.gov/pubmed/7573347 Expression and function of galectin-3, a beta-galactoside-binding lectin, in human monocytes and macrophages.] Am J Pathol. 1995 Oct;147(4):1016-28. PubMed PMID: 7573347; PubMed Central PMCID: PMC1871012.</ref> and potentiates LPS-induced IL-1 production<ref>Jeng KC, Frigeri LG, Liu FT. [http://www.ncbi.nlm.nih.gov/pubmed/7890309 An endogenous lectin, galectin-3 (epsilon BP/Mac-2), potentiates IL-1 production by human monocytes.] Immunol Lett. 1994 Oct;42(3):113-6. PubMed PMID: 7890309.</ref>
:* functions as a chemoattractant for monocytes and macrophages<ref>Sano H, Hsu DK, Yu L, Apgar JR, Kuwabara I, Yamanaka T, Hirashima M, Liu FT. [http://www.ncbi.nlm.nih.gov/pubmed/10925302 Human galectin-3 is a novel chemoattractant for monocytes and macrophages.] J Immunol. 2000 Aug 15;165(4):2156-64. PubMed PMID: 10925302.</ref>
:* is an opsonin and enhances the macrophage clearance of apoptotic neutrophils<ref>Karlsson A, Christenson K, Matlak M, Björstad A, Brown KL, Telemo E, Salomonsson E, Leffler H, Bylund J. [http://www.ncbi.nlm.nih.gov/pubmed/18849325 Galectin-3 functions as an opsonin and enhances the macrophage clearance of apoptotic neutrophils.] Glycobiology. 2009 Jan;19(1):16-20. Epub 2008 Oct 10. PubMed PMID: 18849325.</ref>
:* activates microglia (tissue macrophages of the central nervous system) to phagocytose degenerated myelin mediated by complement receptor-3 and scavenger receptor<ref>Rotshenker S. [http://www.ncbi.nlm.nih.gov/pubmed/19253007 The role of Galectin-3/MAC-2 in the activation of the innate-immune function of phagocytosis in microglia in injury and disease.] J Mol Neurosci. 2009 Sep;39(1-2):99-103. Epub 2009 Feb 28. Review. PubMed PMID:19253007.</ref> 
:* binds to a major xenoantigen, α-Gal [Galα(1,3)Galβ(1,4)GlcNAc], expressed on porcine endothelial cells<ref>Jin R, Greenwald A, Peterson MD, Waddell TK. [http://www.ncbi.nlm.nih.gov/pubmed/16818789 Human monocytes recognize porcine endothelium via the interaction of galectin 3 and alpha-GAL.] J Immunol. 2006 Jul 15;177(2):1289-95. PubMed PMID: 16818789.</ref> and mediates adhesion of human monocytes to porcine endothelial cells
:* suppresses LPS-induced production of inflammatory cytokines by macrophages, including IL-6, IL-12, and TNF-α<ref name="Li 2008">Li Y, Komai-Koma M, Gilchrist DS, Hsu DK, Liu FT, Springall T, Xu D. [http://www.ncbi.nlm.nih.gov/pubmed/18684969 Galectin-3 is a negative regulator of lipopolysaccharide-mediated inflammation.] J Immunol. 2008 Aug 15;181(4):2781-9. PubMed PMID: 18684969.</ref> 

Mast cells 
Galectin-3 induces mediator release from both IgE-sensitized and nonsensitized mast cells<ref>Frigeri LG, Zuberi RI, Liu FT. [http://www.ncbi.nlm.nih.gov/pubmed/8347574 Epsilon BP, a beta-galactoside-binding animal lectin, recognizes IgE receptor (Fc epsilon RI) and activates mast cells.] Biochemistry. 1993 Aug 3;32(30):7644-9. PubMed PMID: 8347574. </ref><ref>Zuberi RI, Frigeri LG, Liu FT. [http://www.ncbi.nlm.nih.gov/pubmed/8200029 Activation of rat basophilic leukemia cells by epsilon BP, an IgE-binding endogenous lectin.] Cell Immunol. 1994 Jun;156(1):1-12. PubMed PMID: 8200029.</ref>, but apoptosis following prolonged treatment (18-44 h)<ref>Suzuki Y, Inoue T, Yoshimaru T, Ra C. [http://www.ncbi.nlm.nih.gov/pubmed/18302939 Galectin-3 but not galectin-1 induces mast cell death by oxidative stress and mitochondrial permeability transition.] Biochim Biophys Acta. 2008 May;1783(5):924-34. Epub 2008 Feb 12. PubMed PMID: 18302939.</ref>. Endogenous Galectin-3 is a positive regulator of mast cell mediator release and cytokine production<ref>Chen HY, Sharma BB, Yu L, Zuberi R, Weng IC, Kawakami Y, Kawakami T, Hsu DK, Liu FT. [http://www.ncbi.nlm.nih.gov/pubmed/17015681 Role of galectin-3 in mast cell functions: galectin-3-deficient mast cells exhibit impaired mediator release and defective JNK expression.] J Immunol. 2006 Oct 15;177(8):4991-7. PubMed PMID: 17015681.</ref>. 

Eosinophils 
Recombinant galectin-3
:* suppresses IL-5 production by human eosinophils<ref>Cortegano I, del Pozo V, Cárdaba B, de Andrés B, Gallardo S, del Amo A, Arrieta I, Jurado A, Palomino P, Liu FT, Lahoz C. [http://www.ncbi.nlm.nih.gov/pubmed/9647247 Galectin-3 down-regulates IL-5 gene expression on different cell types.] J Immunol. 1998 Jul 1;161(1):385-9. PubMed PMID: 9647247.</ref>
:* mediates rolling and adhesion of eosinophils on immobilized VCAM-1 under conditions of flow<ref>Rao SP, Wang Z, Zuberi RI, Sikora L, Bahaie NS, Zuraw BL, Liu FT, Sriramarao P. [http://www.ncbi.nlm.nih.gov/pubmed/18025226 Galectin-3 functions as an adhesion molecule to support eosinophil rolling and adhesion under conditions of flow.] J Immunol. 2007 Dec 1;179(11):7800-7. PubMed PMID: 18025226.</ref>. 

''Functions demonstrated in vivo.'' 

A number of biological functions have been identified by using ''Lgals3-/-'' mice. With respect to acute inflammation and allergic inflammation galectin-3:
:# has a proinflammatory role in acute inflammation induced by intraperitoneal injection of thioglycollate broth, in terms of the neutrophil response,<ref name="Colnot 1998"/> and macrophage response<ref>Hsu DK, Yang RY, Pan Z, Yu L, Salomon DR, Fung-Leung WP, Liu FT. [http://www.ncbi.nlm.nih.gov/pubmed/10702423 Targeted disruption of the galectin-3 gene results in attenuated peritoneal inflammatory responses.] Am J Pathol. 2000 Mar;156(3):1073-83. PubMed PMID: 10702423; PubMed Central PMCID: PMC1876862.</ref>
:# promotes allergic airway inflammation, airway hyperresponsiveness, and a Th2 response in a mouse model of asthma in which mice are sensitized with ovalbumin systemically and challenged with the same antigen through the airways<ref>Zuberi RI, Hsu DK, Kalayci O, Chen HY, Sheldon HK, Yu L, Apgar JR, Kawakami T, Lilly CM, Liu FT. [http://www.ncbi.nlm.nih.gov/pubmed/15579447 Critical role for galectin-3 in airway inflammation and bronchial hyperresponsiveness in a murine model of asthma.] Am J Pathol. 2004 Dec;165(6):2045-53. PubMed PMID: 15579447; PubMed Central PMCID: PMC1618718.</ref>
:# promotes allergic skin inflammation and a systemic Th2 response in a model of atopic dermatitis, in which mice are repeatedly sensitized with ovalbumin epicutaneously<ref name="Saegusa 2009"/>
:# promotes allergic contact hypersensitivity, in which mice are sensitized with the hapten oxazalone, and then challenged with the same hapten at another skin site<ref name="Hsu 2009"/> (38)
However, rats and mice treated by intranasal delivery of cDNA encoding Galectin-3 showed reduced eosinophil infiltration following airway antigen challenge<ref>del Pozo V, Rojo M, Rubio ML, Cortegano I, Cárdaba B, Gallardo S, Ortega M, Civantos E, López E, Martín-Mosquero C, Peces-Barba G, Palomino P, González-Mangado N, Lahoz C. [http://www.ncbi.nlm.nih.gov/pubmed/12204873 Gene therapy with galectin-3 inhibits bronchial obstruction and inflammation in antigen challenged rats through interleukin-5 gene downregulation.] Am J Respir Crit Care Med. 2002 Sep 1;166(5):732-7. PubMed PMID: 12204873.</ref><ref>López E, del Pozo V, Miguel T, Sastre B, Seoane C, Civantos E, Llanes E, Baeza ML, Palomino P, Cárdaba B, Gallardo S, Manzarbeitia F, Zubeldia JM, Lahoz C. [http://www.ncbi.nlm.nih.gov/pubmed/16424226 Inhibition of chronic airway inflammation and remodeling by galectin-3 gene therapy in a murine model.] J Immunol. 2006 Feb 1;176(3):1943-50. PubMed PMID: 16424226.</ref>. 

With regard to autoimmunity, galectin-3
:* contributes to the disease severity in a mouse model of autoimmune encephalomyelitis (EAE) induced by immunization with a myelin oligodendrocyte glycoprotein peptide<ref>Jiang HR, Al Rasebi Z, Mensah-Brown E, Shahin A, Xu D, Goodyear CS, Fukada SY, Liu FT, Liew FY, Lukic ML. [http://www.ncbi.nlm.nih.gov/pubmed/19124760 Galectin-3 deficiency reduces the severity of experimental autoimmune encephalomyelitis.] J Immunol. 2009 Jan 15;182(2):1167-73. PubMed PMID: 19124760.</ref>
:* suppresses the development of glomerulopathy in mice rendered diabetic with streptozotocin, associated with lower accumulation of advanced glycation end products (AGE) in the kidneys<ref>Pugliese G, Pricci F, Iacobini C, Leto G, Amadio L, Barsotti P, Frigeri L, Hsu DK, Vlassara H, Liu FT, Di Mario U. [http://www.ncbi.nlm.nih.gov/pubmed/11689472 Accelerated diabetic glomerulopathy in galectin-3/AGE receptor 3 knockout mice.] FASEB J. 2001 Nov;15(13):2471-9. PubMed PMID: 11689472.</ref>
:* may serve as an AGE receptor and protects from AGE-induced tissue injury<ref>Iacobini C, Menini S, Oddi G, Ricci C, Amadio L, Pricci F, Olivieri A, Sorcini M, Di Mario U, Pesce C, Pugliese G. [http://www.ncbi.nlm.nih.gov/pubmed/15361471 Galectin-3/AGE receptor 3 knockout mice show accelerated AGE-induced glomerular injury: evidence for a protective role of galectin-3 as an AGE receptor.] FASEB J. 2004 Nov;18(14):1773-5. Epub 2004 Sep 10. PubMed PMID: 15361471</ref> and age-dependent changes<ref>Iacobini C, Oddi G, Menini S, Amadio L, Ricci C, Di Pippo C, Sorcini M, Pricci
F, Pugliese F, Pugliese G. [http://www.ncbi.nlm.nih.gov/pubmed/15870382 Development of age-dependent glomerular lesions in galectin-3/AGE-receptor-3 knockout mice.] Am J Physiol Renal Physiol. 2005 Sep;289(3):F611-21. Epub 2005 May 3. PubMed PMID: 15870382.</ref>
:* contributes to development of diabetes induced by multiple low doses of streptozotocin<ref>Mensah-Brown EP, Al Rabesi Z, Shahin A, Al Shamsi M, Arsenijevic N, Hsu DK, Liu FT, Lukic ML. [http://www.ncbi.nlm.nih.gov/pubmed/18845486 Targeted disruption of the galectin-3 gene results in decreased susceptibility to multiple low dose streptozotocin-induced diabetes in mice.] Clin Immunol. 2009 Jan;130(1):83-8. Epub 2008 Oct 8. PubMed PMID: 18845486.</ref>; this may be related to its upregulation of TNF-&alpha: and nitric oxide production by macrophages
:* contributes to ischemia and neovascularization in retina in a mouse model of oxygen-induced proliferative retinopathy after perfusion of preformed AGEs<ref>Stitt AW, McGoldrick C, Rice-McCaldin A, McCance DR, Glenn JV, Hsu DK, Liu FT, Thorpe SR, Gardiner TA. [http://www.ncbi.nlm.nih.gov/pubmed/15734857 Impaired retinal angiogenesis in diabetes: role of advanced glycation end products and galectin-3.] Diabetes. 2005 Mar;54(3):785-94. PubMed PMID: 15734857.</ref>
:* is expressed in foam cells and macrophages in atherosclerotic lesions<ref>Nachtigal M, Al-Assaad Z, Mayer EP, Kim K, Monsigny M. [http://www.ncbi.nlm.nih.gov/pubmed/9588889 Galectin-3 expression in human atherosclerotic lesions.] Am J Pathol. 1998 May;152(5):1199-208. PubMed PMID: 9588889; PubMed Central PMCID: PMC1858580.</ref> and contributes to the development of atherosclerosis in apolipoprotein (Apo)E-deficient mice<ref>Nachtigal M, Ghaffar A, Mayer EP. [http://www.ncbi.nlm.nih.gov/pubmed/18156214 Galectin-3 gene inactivation reduces atherosclerotic lesions and adventitial inflammation in ApoE-deficient mice.] Am J Pathol. 2008 Jan;172(1):247-55. Epub 2007 Dec 21. PubMed PMID: 18156214; PubMed Central PMCID: PMC2189631.</ref> 

''Infectious processes.'' 

The roles of galectin-3 in a large number of mouse models of infectious disease have been studied in ''Lgals3-/-'' mice, as follows:
:# suppresses LPS-induced shock accompanied by lower inflammatory cytokine and nitric oxide production, possibly a result of its ability to bind to this endotoxin. However, it enhances sensitivity to ''Salmonella'' infection<ref name="Li 2008"/>
:# contributes to recruitment of neutrophils to lungs of mice infected with ''S. pneumoniae'' and has a protective role in development of pneumonia after the infection, possibly by augmenting the function of neutrophils<ref>Nieminen J, St-Pierre C, Bhaumik P, Poirier F, Sato S. [http://www.ncbi.nlm.nih.gov/pubmed/18250456 Role of galectin-3 in leukocyte recruitment in a murine model of lung infection by Streptococcus pneumoniae.] J Immunol. 2008 Feb 15;180(4):2466-73. PubMed PMID: 18250456.</ref>
:# contributes to inflammatory responses in intestines, liver, and brain (but not in lungs) and a lower systemic Th1-polarized response in mice infected by ''Toxoplasma gondii''<ref name="Bernardes 2006"/>; galectin-3 suppresses parasite burden in the brain
:# promotes development of T and B responses in the spleen, as well formation of liver granulomas, but suppresses the Th1-polarized response in mice infected with ''Schistosoma mansoni''<ref name="Breuilh 2007"/>
:# contributes to sensitivity in lethal effects of ''Rhodococcus equi'', a facultative intracellular bacterium of macrophages<ref>Ferraz LC, Bernardes ES, Oliveira AF, Ruas LP, Fermino ML, Soares SG, Loyola AM, Oliver C, Jamur MC, Hsu DK, Liu FT, Chammas R, Roque-Barreira MC. [http://www.ncbi.nlm.nih.gov/pubmed/18825751 Lack of galectin-3 alters the balance of innate immune cytokines and confers resistance to Rhodococcus equi infection.] Eur J Immunol. 2008 Oct;38(10):2762-75. PubMed PMID: 18825751.</ref>. It suppresses inflammatory responses, including production of the Th1 cytokines IL-12 and IFN-γ, as well as IL-1β 
:# promotes resistance of mice to infection by “Paracoccidioides brasiliensis” and favors a Th1-polarized immune response<ref>Ruas LP, Bernardes ES, Fermino ML, de Oliveira LL, Hsu DK, Liu FT, Chammas R, Roque-Barreira MC. [http://www.ncbi.nlm.nih.gov/pubmed/19229338 Lack of galectin-3 drives response to Paracoccidioides brasiliensis toward a Th2-biased immunity.] PLoS One. 2009;4(2):e4519. Epub 2009 Feb 20. PubMed PMID: 19229338; PubMed Central PMCID: PMC2641003.</ref> 

Interestingly, recombinant Galectin-3 is able to induce cell death in the yeast Candida albicans in vitro<ref>Kohatsu L, Hsu DK, Jegalian AG, Liu FT, Baum LG. [http://www.ncbi.nlm.nih.gov/pubmed/16982911 Galectin-3 induces death of Candida species expressing specific beta-1,2-linked mannans.] J Immunol. 2006 Oct 1;177(7):4718-26. PubMed PMID: 16982911.</ref>. 

'''Tumor development/progression.''' 
Galectin-3 expression is altered in a variety of tumors in comparison to normal tissues<ref>Danguy A, Camby I, Kiss R. [http://www.ncbi.nlm.nih.gov/pubmed/12223276 Galectins and cancer.] Biochim Biophys Acta. 2002 Sep 19;1572(2-3):285-93. Review. PubMed PMID: 12223276.</ref>. The diagnostic utility of Galectin-3 expression in thyroid cancer has been extensively demonstrated (e.g., <ref>Chiu CG, Strugnell SS, Griffith OL, Jones SJ, Gown AM, Walker B, Nabi IR, Wiseman SM. [http://www.ncbi.nlm.nih.gov/pubmed/20363921 Diagnostic utility of galectin-3 in thyroid cancer.] Am J Pathol. 2010 May;176(5):2067-81. Epub 2010 Apr 2. PubMed PMID: 20363921; PubMed Central PMCID: PMC2861072.</ref><ref>Carpi A, Mechanick JI, Saussez S, Nicolini A. [http://www.ncbi.nlm.nih.gov/pubmed/20578236 Thyroid tumor marker genomics and proteomics: diagnostic and clinical implications.] J Cell Physiol. 2010 Sep;224(3):612-9. PubMed PMID: 20578236.</ref>). The role of Galectin-3 in tumor growth, progression, and metastasis has been comprehensively documented (reviewed in <ref name="Liu 2005"/>). There is evidence that Galectin-3 expression is necessary for the initiation of the transformed phenotype of tumors, possibly related to its ability to interact with oncogenic K-Ras<ref>Shalom-Feuerstein R, Plowman SJ, Rotblat B, Ariotti N, Tian T, Hancock JF, Kloog Y. [http://www.ncbi.nlm.nih.gov/pubmed/18701484 K-ras nanoclustering is subverted by overexpression of the scaffold protein galectin-3.] Cancer Res. 2008 Aug 15;68(16):6608-16. PubMed PMID: 18701484; PubMed Central PMCID: PMC2587079.</ref>. 

The most extensively studied function of Galectin-3 is its inhibition of apoptosis in a range of tumor cell types exposed to diverse apoptotic stimuli (reviewed in <ref>Yang RY, Rabinovich GA, Liu FT. [http://www.ncbi.nlm.nih.gov/pubmed/18549522 Galectins: structure, function and therapeutic potential.] Expert Rev Mol Med. 2008 Jun 13;10:e17. Review. PubMed PMID: 18549522.</ref>). The mechanism by which Galectin-3 inhibits apoptosis in tumor cells has been extensively studied <ref name="Liu 2005"/><ref>Nakahara S, Oka N, Raz A. [http://www.ncbi.nlm.nih.gov/pubmed/15843888 On the role of galectin-3 in cancer apoptosis.] Apoptosis. 2005; 10:267-75. PubMed PMID: 15843888.</ref>). Apoptosis induced by the tumor suppressor p53 involves repression of Galectin-3<ref>Cecchinelli B, et al. [http://www.ncbi.nlm.nih.gov/pubmed/16738336 Repression of the antiapoptotic molecule galectin-3 by homeodomain-interacting protein kinase 2-activated p53 is required for p53-induced apoptosis.] Mol Cell Biol. 2006; 26:4746-57. PubMed PMID: 16738336; PMCID: PubMed Central PMC1489111</ref>. 

Endogenous galectin-3 promotes tumor cell growth (reviewed in <ref name="Liu 2005"/>), one mechanism may involve interaction with transcription factors<ref>Paron I, et al. [http://www.ncbi.nlm.nih.gov/pubmed/12615069 Nuclear localization of Galectin-3 in transformed thyroid cells: a role in transcriptional regulation.] Biochem Biophys Res Commun. 2003; 302:545-53. PubMed PMID: 12615069.</ref>, another may be facilitation of the signaling of K-Ras to Raf and PI3 kinase<ref>Ashery U, et al. [http://www.ncbi.nlm.nih.gov/pubmed/16691442 Spatiotemporal organization of Ras signaling: rasosomes and the galectin switch.] Cell Mol Neurobiol. 2006; 26:471-95. PubMed PMID: 16691442.</ref>. Endogenous galectin-3 also regulates tumor progression by influencing cell cycling; its binds to β-catenin and stimulates the expression of cyclin D and c-Myc<ref>Shimura T, Takenaka Y, Tsutsumi S, Hogan V, Kikuchi A, Raz A. [http://www.ncbi.nlm.nih.gov/pubmed/15374939 Galectin-3, a novel binding partner of beta-catenin.] Cancer Res. 2004; 64:6363-7. PubMed PMID: 15374939.</ref>. 

Galectin-3 can affect tumor metastasis by exerting its effect in the tumor microenvironment, including angiogenesis and fibrosis<ref name="Liu 2005"/>. Galectin-3 plays a role in activation of myofibroblasts in the liver and contributes to liver fibrosis induced by carbon tetrachloride<ref>Henderson NC, et al. [http://www.ncbi.nlm.nih.gov/pubmed/16549783 Galectin-3 regulates myofibroblast activation and hepatic fibrosis.] Proc Natl Acad Sci U S A. 2006; 103:5060-5. PubMed PMID: 16549783; PubMed Central PMCID: PMC1458794.</ref>. 

In a human melanoma tumor model in immunodeficient mice, administration of galectin-3 results in suppressing the tumor killing effect of tumor-reactive T cells<ref>Peng W, Wang HY, Miyahara Y, Peng G, Wang RF. [http://www.ncbi.nlm.nih.gov/pubmed/18757439 Tumor-associated galectin-3 modulates the function of tumor-reactive T cells.] Cancer Res. 2008 Sep 1;68(17):7228-36. PubMed PMID: 18757439.</ref>. Tumor-associated galectin-3 may also contribute to tumor immune escape by rendering tumor-infiltrating cytolytic lymphocytes anergic<ref>Demotte N, Stroobant V, Courtoy PJ, Van Der Smissen P, Colau D, Luescher IF, Hivroz C, Nicaise J, Squifflet JL, Mourad M, Godelaine D, Boon T, van der Bruggen P. [http://www.ncbi.nlm.nih.gov/pubmed/18342010 Restoring the association of the T cell receptor with CD8 reverses anergy in human tumor-infiltrating lymphocytes.] Immunity. 2008 Mar;28(3):414-24. PubMed PMID: 18342010.</ref>. 

Galectin-3 affects the motility of tumor cells and influences their invasiveness in vitro. However, both positive and negative effects have been reported<ref>Le Marer N, Hughes RC. [http://www.ncbi.nlm.nih.gov/pubmed/8647922 Effects of the carbohydrate-binding protein galectin-3 on the invasiveness of human breast carcinoma cells.] J Cell Physiol. 1996; 168:51-8. PubMed PMID: 8647922.</ref><ref>Moisa A, et al. [http://www.ncbi.nlm.nih.gov/pubmed/17695496 Growth/adhesion-regulatory tissue lectin galectin-3: stromal presence but not cytoplasmic/nuclear expression in tumor cells as a negative prognostic factor in breast cancer.] Anticancer Res. 2007; 27:2131-9. PubMed PMID: 17695496.</ref>. Endogenous galectin-3 can also contribute to cell motility and in vitro invasiveness<ref>Matarrese P, et al. [http://www.ncbi.nlm.nih.gov/pubmed/10699929 Galectin-3 overexpression protects from apoptosis by improving cell adhesion properties.] Int J Cancer. 2000; 85:545-54. PubMed PMID: 10699929.</ref><ref>O'Driscoll L, Linehan R, Liang YH, Joyce H, Oglesby I, Clynes M. [http://www.ncbi.nlm.nih.gov/pubmed/12530054 Galectin-3 expression alters adhesion, motility and invasion in a lung cell line (DLKP), in vitro.] Anticancer Res. 2002; 22:3117-25. PubMed PMID: 12530054.</ref><ref>Shimura T, et al. [http://www.ncbi.nlm.nih.gov/pubmed/15867344 Implication of galectin-3 in Wnt signaling.] Cancer Res. 2005; 65:3535-7. PubMed PMID: 15867344.</ref>. Galectin-3 has angiogenic activity, which may be related to its ability to induce migration of endothelial cells<ref>Nangia-Makker P, et al. [http://www.ncbi.nlm.nih.gov/pubmed/10702407 Galectin-3 induces endothelial cell morphogenesis and angiogenesis.] Am J Pathol. 2000; 156:899-909. PubMed PMID: 10702407; PubMed Central PMCID: PMC1876842.</ref>. 

Studies with animal models have provided evidence for the role of galectins in tumor metastasis in vivo (reviewed in <ref name="Liu 2005"/>). For example, liver metastases of human adenocarcinoma xenotransplants in SCID mice are inhibitable by anti-galectin-3 antibody. Breast carcinoma cells overexpressing transgenic galectin-3 have higher metastatic potential. In an orthotopic nude mouse model of human breast cancer, tumor metastasis is inhibitable by C-terminal domain fragment of galectin-3 (galectin-3C)<ref>John CM, Leffler H, Kahl-Knutsson B, Svensson I, Jarvis GA. [http://www.ncbi.nlm.nih.gov/pubmed/12796408 Truncated galectin-3 inhibits tumor growth and metastasis in orthotopic nude mouse model of human breast cancer.] Clin Cancer Res. 2003; 9:2374-83. PubMed PMID: 12796408.</ref>. 

Galectin-3 contributes to chemotherapeutic resistance of thyroid cancer cells in vitro, the progression of disease in prostate cancer<ref>Wang Y, et al. [http://www.ncbi.nlm.nih.gov/pubmed/19286570 Regulation of prostate cancer progression by galectin-3.] Am J Pathol. 2009; 174:1515-23. PubMed PMID: 19286570; PubMed Central PMCID: PMC2671381.</ref> and development of carcinogen-induced lung tumorigenesis<ref>Abdel-Aziz HO, et al. [http://www.ncbi.nlm.nih.gov/pubmed/18204863 Targeted disruption of the galectin-3 gene results in decreased susceptibility to NNK-induced lung tumorigenesis: an oligonucleotide microarray study.] J Cancer Res Clin Oncol. 2008; 134:777-88. PubMed PMID: 18204863.</ref> in mouse models. However, the absence of galectin-3 may not affect the evolution of cancers<ref>Eude-Le Parco I, et al. [http://www.ncbi.nlm.nih.gov/pubmed/18849326 Genetic assessment of the importance of galectin-3 in cancer initiation, progression, and dissemination in mice.] Glycobiology. 2009; 19:68-75. PubMed PMID: 18849326.</ref>. Galectin-3-targeting small molecule inhibitors enhancs apoptosis induced by chemo- and radio-therapy in papillary thyroid cancer in vitro<ref>Lin CI, et al. [http://www.ncbi.nlm.nih.gov/pubmed/19825987 Galectin-3 targeted therapy with a small molecule inhibitor activates apoptosis and enhances both chemosensitivity and radiosensitivity in papillary thyroid cancer.] Mol Cancer Res. 2009; 7:1655-62. PubMed PMID: 19825987.</ref>. GCS-100, a galectin-3 antagonist, induces myeloma cell death in vitro<ref>Streetly MJ, Maharaj L, Joel S, Schey SA, Gribben JG, Cotter FE. [http://www.ncbi.nlm.nih.gov/pubmed/20190189 GCS-100, a novel galectin-3 antagonist, modulates MCL-1, NOXA, and cell cycle to induce myeloma cell death.] Blood. 2010; 115:3939-48. PubMed PMID: 20190189.</ref>). 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=galectin-3&maxresults=20 CFG database search results for Galectin-3].

=== Glycan profiling ===
 

=== Glycogene microarray ===
Gene expression analyses have been performed on several cell types and tissues at [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=galectin-3&cat=coree Core E] of the CFG. Probes for human galectin-3 have been included in all versions of the CFG glycogene chip, and probes for mouse galectin-3 are included on versions 2, 3, and 4.
 

=== Knockout mouse lines ===
Galectin-3 knockout mice were [https://www.functionalglycomics.org/glycomics/publicdata/phenotyping.jsp phenotyped by Core G] of the CFG and continue to be used by investigators to study the biological functions of Galectin-3.

=== Glycan array ===
Investigators have used CFG carbohydrate compounds and glycan arrays to study ligand binding specificity of Galectin-3 (for example, click [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_GLYCAN_v2_10_02132003 here]). To see all glycan array results for Galectin-3, click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=galectin-3&cat=coreh here].

== Related GBPs ==
Structure unique among galectins in mammals; homologues in vertebrates & invertebrates.

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Linda Baum, Richard Cummings, Michael Demetriou, Daniel Hsu, Fu-Tong Liu

Macrophage galactose lectin (MGL)

2011-04-15T07:48:36Z

Kurt Drickamer: /* Carbohydrate ligands */

Macrophage galactose binding lectin (MGL) is the best studied of the multiple C-type lectins on macrophages <ref name="Kawasaki 1986">Kawasaki T, Ii M, Kozutsumi Y and Yamashina I. 1986. Isolation and characterization of a receptor lectin specific for galactose/N-acetylgalactosamine from macrophages. Carbohydr Res. 151:197-206</ref><ref name="Suzuki 1996">Suzuki N, Yamamoto K, Toyoshima S, Osawa T and Irimura T. 1996. Molecular cloning and expression of cDNA encoding human macrophage C-type lectin. Its unique carbohydrate binding specificity for Tn antigen. J Immunol. 156:128-135</ref>. It is also representative of the subclass of C-type lectins that bind galactose-related sugars. MGL consists of one CRD domain and contains cytoplasmic internalization motifs for endocytosis. No signaling properties have been described yet for MGL. Human MGL (CD301) and rat MGL are encoded by a single gene, whereas mice contain two MGL copies, mMGL-1 and mMGL-2 that differ in carbohydrate specificity <ref name=Tsuiji 2002">Tsuiji M, Fujimori M, Ohashi Y, Higashi N, Onami TM, Hedrick SM and Irimura T. 2002. Molecular cloning and characterization of a novel mouse macrophage C-type lectin, mMGL2, which has a distinct carbohydrate specificity from mMGL1. J Biol Chem. 277:28892-28901</ref><ref name="Singh 2009">Singh SK, Streng-Ouwehand I, Litjens M, Weelij DR, Garca-Vallejo JJ, van Vliet SJ, Saeland E, van Kooyk Y. 2009. Characterization of murine MGL1 and MGL2 C-type lectins: distinct glycan specificities and tumor binding properties. Mol Immunol 46: 1240-1249</ref><ref name="Higashi 2002">Higashi N, Fujioka K, Denda-Nagai K, Hashimoto S, Nagai S, Sato T, Fujita Y, Morikawa A, Tsuiji M, Miyata-Takeuchi M, Sano Y, Suzuki N, Yamamoto K, Matsushima K and Irimura T. 2002. The macrophage C-type lectin specific for galactose/N-acetylgalactosamine is an endocytic receptor expressed on monocyte-derived immature dendritic cells. J Biol Chem. 277:20686-20693</ref>.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
In addition to creating the knockout for the two mouse forms of MGL, PIs have been involved in extensive studies of binding specificity and mechanism of ligand binding as well as the role of the receptor in macrophage signaling.
* PIs working on MGL include: Nicolai Bovin, Kurt Drickamer, Toshisuke Kawasaki, Cheng Liu, Yvette van Kooyk, Hui Wu, Joy Burchell,Joyce Taylor-Papadimitriou
* Non-PIs with who have used CFG resources to study MGL include: Siamon Gordon, Alan Saltiel
* PIs working on MGL-related glycan-binding proteins (GBPs), particularly Mincle, include: Anthony dApice, Joshua Fierer, Rikard Holmdahl, Christopher O'Callaghan, Judy Teale, Christine Wells
* Non-PIs with who have used resources to study related members of this paradigm group include: Roland Lang, Ulrich Maus, Gunnar Nilsson, Kenneth Rock

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about MGL, its carbohydrate ligand(s), and how they interact to mediate cell communication. Further information about MGL can be found in its [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_hum_Ctlect_217&sideMenu=no GBP Molecule Page] in the CFG database.
=== Carbohydrate ligands ===
*mMGL1 binds Lewis X and Lewis A structures, whereas mMGL2 recognizes N-acetylgalactosamine (GalNAc) and galactose, including the O-linked Tn-antigen and TF-antigen <ref name=Tsuiji 2002"/><ref name="Singh 2009"/><Ref name="Napoletano2007"/>
*hMGL binds terminal α- and β-linked GalNAc residues on glycoproteins, glycolipids and bacterial LPS, including Tn antigen and GalNAcβ1-4GlcNAc-R (LDN) antigens <ref name="Suzuki 1996"/><ref name="Van Vliet 2005">van Vliet SJ, van Liempt E, Saeland E, Aarnoudse CA, Appelmelk B, Irimura T, Geijtenbeek TB, Blixt O, Alvarez R, van Die I and van Kooyk Y. 2005. Carbohydrate profiling reveals a distinctive role for the C-type lectin MGL in the recognition of helminth parasites and tumor antigens by dendritic cells. Int Immunol. 17:661-669</ref><ref>van Sorge NM, Bleumink NM, van Vliet SJ, Saeland E, van der Pol WL, van Kooyk Y and van Putten JP. 2009. N-glycosylated proteins and distinct lipooligosaccharide glycoforms of Campylobacter jejuni target the human C-type lectin receptor MGL. Cell Microbiol. 11:1768-1781</ref><ref>Saeland E, van Vliet SJ, Backstrom M, van den Berg VC, Geijtenbeek TB, Meijer GA and van Kooyk Y. 2007. The C-type lectin mgl expressed by dendritic cells detects glycan changes on Muc1 in colon carcinoma. Cancer Immunol Immunother. 56:1225-1236</ref><ref name="Napoletano2007">Napoletano C, Rughetti A, Tarp M.P.A, Coleman J Bennett,E.P, Picco G, Sale P, Denda-Hagai K, Irimura T, Mandel U, Clausen H, Frati L, Taylor-Papadimitriou J, Burchell J, Nuti M. Tumour associated Tn-MUC1 glycoform is internalised througfh the macrophage galactose C-type lectin and delivered to the HLA class I and Class II compartments in dendritic cells. Cancer Research, 2007, 67(17): 8358-8367</ref>.
*hMGL can also bind to STn when presented on a peptide or polyacrylamide backbone.

=== Cellular expression of GBP and ligands ===
MGL is expressed on dendritic cells and macrophages. <ref name="Higashi 2002"/><ref name=" van Vliet SJ1200 ">van Vliet SJ, Gringhuis SI, Geijtenbeek TB and van Kooyk Y. 2006. Regulation of effector T cells by antigen-presenting cells via interaction of the C-type lectin MGL with CD45. Nat Immunol. 7:1200-1208</ref>
 
The Tn ligand is expressed by many cancer cells especially breast cancers where it is expressed on more than 90% of breast carcinomas <ref> Sørensen AL, “et al”. Chemoenzymatically synthesized multimeric Tn/STn MUC1 glycopeptides elicit cancer-specific anti-MUC1 antibody responses and override tolerance. “Glycobiology” 16, 96-107 (2006) </ref>. although STn is also expressed by carcinomas, especially colorectal and in 25-30% of breast cancers.

=== Biosynthesis of ligands ===
The Tn ligand can be expressed in cervical cancer due to mutations in Cosmc <ref> Ju T, “et al”. Human tumor antigens Tn and sialyl Tn arise from mutations in Cosmc “Cancer Research” 68, 1636-1646 (2008) </ref>. a molecular chaperone that is essential for the activity of the T synthase, the glycosyltransferase that catalyses the addition Gal to GalNAcαSer/Thr, forming the T antigen (Galβ1,3GalNAcαSer/Thr).
Although the vast majority of breast cancers express Tn there is no evidence of mutated Cosmc in these cancers therefore another mechanism for the expression of the Tn ligand must be active. Moreover the expression of STn in breast cancer is perfectly correlated with the turning on of the transcription of ST6GalNAc-I <ref> Sewell R, “et al”. The ST6GalNAc-I sialyltransferase localizes throughout the Golgi and is responsible for the synthesis of the tumor-associated sialyl-Tn O-glycan in human breast cancer. “J Biol Chem” 281, 3586-3594 (2006) </ref>.
 

=== Structure ===
[[image:MGL.jpg]] 
MGL is an oligomeric type II transmembrane protein. The CRD of the major subunit of the hepatic asialoglycoprotein receptor has been determined<ref name="Meier2000">Meier, M, Bider, MD, Malashkevich, VN, Spiess, M and Burkhard, P. 2000. Crystal structure of the carbohydrate recognition domain of the H1 subunit of the asialoglycoprotein receptor. J Mol Biol 300:857–865</ref> and the structure of a galatose-binding mutant of mannose-binding protein provides experimental evidence for how galactose- and GalNAc-terminated ligands can bind to the receptor.<ref name="Kolatkar2000">Kolatkar, AR, Leung, AK, Isecke, R, Brossmer, R, Drickamer, K and Weis, WI. 1998. Mechanism of N-acetylgalactosamine binding to a C-type animal lectin carbohydrate-recognition domain. J Biol Chem 273:19502-19508</ref>
 

=== Biological roles of GBP-ligand interaction ===
*MGL is a highly efficient internalization receptor <ref name="Higashi 2002"/><ref>Valladeau J, Duvert-Frances V, Pin JJ, Kleijmeer MJ, Ait-Yahia S, Ravel O, Vincent C, Vega F, Jr., Helms A, Gorman D, Zurawski SM, Zurawski G, Ford J and Saeland S. 2001. Immature human dendritic cells express asialoglycoprotein receptor isoforms for efficient receptor-mediated endocytosis. J Immunol. 167:5767-5774</ref>
*hMGL regulates T-cell receptor mediated signaling and T-cell dependent cytokine responses <ref name=" van Vliet SJ1200 "/>
*mMGL1 promotes adipose tissue inflammation and insulin resistance <ref>Westcott DJ, Delproposto JB, Geletka LM, Wang T, Singer K, Saltiel AR, Lumeng CN. 2009. MGL1 promotes adipose tissue inflammation and insulin resistance by regulating 7/4hi monocytes in obesity. J Exp Med 206: 3143-56</ref>
*mMGL2 promotes enhances both MHC class II and class I presentation antigen in dendritic cells (DCs) <ref>Singh SK, Streng-Ouwehand I, Litjens M, Kalay H, Saeland E, Van Kooyk Y. 2010. Tumour-associated glycan modifications of antigen enhance MGL2 dependent uptake and MHC class I restricted CD8 T cell responses. Int. J. Cancer, in press</ref>

 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=MGL&maxresults=20 CFG database search results for MGL].

=== Glycan profiling ===

 
=== Glycogene microarray ===
Probes for the single human MGL and both mouse MGLs have been included in all versions of the CFG glycogene chip.
 

=== Knockout mouse lines ===
Knockouts for one of the mouse orthologs of MGL were distributed by the CFG and the [https://www.functionalglycomics.org/glycomics/publicdata/phenotyping.jsp phenotype] was analyzed.

=== Glycan array ===
The glycan-binding specificity of [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_GLYCAN_v2_13_11262003 human] and [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_2010 mouse] versions of MGL have been analyzed by glycan array screening <ref name="Van Vliet 2005"/><ref name="Singh 2009"/>. See all glycan array results for MGL [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=mgl&cat=coreh here]. See glycan array results for these related GBPs: [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=mannose%20AND%20receptor%20NOT%20asialoglycoprotein&cat=coreh mannose receptor,] [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=mincle&cat=coreh mincle,] [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=MCL&cat=coreh macrophage C-type lectin (MCL),] and [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=dectin-1&cat=coreh dectin-1.]

== Related GBPs ==
Other C-type lectins on macrophages include the mannose receptor [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=DC-SIGNR&maxresults=20 (CFG data)], mincle <ref>Wells CA, Salvage-Jones JA, Li X, Hitchens K, Butcher S, Murray RZ, Beckhouse AG, Lo YL, Manzanero S, Cobbold C, Schroder K, Ma B, Orr S, Stewart L, Lebus D, Sobieszczuk P, Hume DA, Stow J, Blanchard H, Ashman RB. 2008. The macrophage-inducible C-type lectin, mincle, is an essential component of the innate immune response to Candida albicans. J Immunol 180: 7404-7413</ref> [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=mincle&maxresults=20 (CFG data)], macrophage C- type lectin (MCL) [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=MCL&maxresults=20 (CFG data)], and dectin-1 [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=dectin-1&maxresults=20 (CFG data)].

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Kurt Drickamer, Joyce Taylor-Papadimitriou, Yvette van Kooyk, Irma van Die

Macrophage galactose lectin (MGL)

2011-04-15T07:48:18Z

Kurt Drickamer: /* Carbohydrate ligands */

Macrophage galactose binding lectin (MGL) is the best studied of the multiple C-type lectins on macrophages <ref name="Kawasaki 1986">Kawasaki T, Ii M, Kozutsumi Y and Yamashina I. 1986. Isolation and characterization of a receptor lectin specific for galactose/N-acetylgalactosamine from macrophages. Carbohydr Res. 151:197-206</ref><ref name="Suzuki 1996">Suzuki N, Yamamoto K, Toyoshima S, Osawa T and Irimura T. 1996. Molecular cloning and expression of cDNA encoding human macrophage C-type lectin. Its unique carbohydrate binding specificity for Tn antigen. J Immunol. 156:128-135</ref>. It is also representative of the subclass of C-type lectins that bind galactose-related sugars. MGL consists of one CRD domain and contains cytoplasmic internalization motifs for endocytosis. No signaling properties have been described yet for MGL. Human MGL (CD301) and rat MGL are encoded by a single gene, whereas mice contain two MGL copies, mMGL-1 and mMGL-2 that differ in carbohydrate specificity <ref name=Tsuiji 2002">Tsuiji M, Fujimori M, Ohashi Y, Higashi N, Onami TM, Hedrick SM and Irimura T. 2002. Molecular cloning and characterization of a novel mouse macrophage C-type lectin, mMGL2, which has a distinct carbohydrate specificity from mMGL1. J Biol Chem. 277:28892-28901</ref><ref name="Singh 2009">Singh SK, Streng-Ouwehand I, Litjens M, Weelij DR, Garca-Vallejo JJ, van Vliet SJ, Saeland E, van Kooyk Y. 2009. Characterization of murine MGL1 and MGL2 C-type lectins: distinct glycan specificities and tumor binding properties. Mol Immunol 46: 1240-1249</ref><ref name="Higashi 2002">Higashi N, Fujioka K, Denda-Nagai K, Hashimoto S, Nagai S, Sato T, Fujita Y, Morikawa A, Tsuiji M, Miyata-Takeuchi M, Sano Y, Suzuki N, Yamamoto K, Matsushima K and Irimura T. 2002. The macrophage C-type lectin specific for galactose/N-acetylgalactosamine is an endocytic receptor expressed on monocyte-derived immature dendritic cells. J Biol Chem. 277:20686-20693</ref>.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
In addition to creating the knockout for the two mouse forms of MGL, PIs have been involved in extensive studies of binding specificity and mechanism of ligand binding as well as the role of the receptor in macrophage signaling.
* PIs working on MGL include: Nicolai Bovin, Kurt Drickamer, Toshisuke Kawasaki, Cheng Liu, Yvette van Kooyk, Hui Wu, Joy Burchell,Joyce Taylor-Papadimitriou
* Non-PIs with who have used CFG resources to study MGL include: Siamon Gordon, Alan Saltiel
* PIs working on MGL-related glycan-binding proteins (GBPs), particularly Mincle, include: Anthony dApice, Joshua Fierer, Rikard Holmdahl, Christopher O'Callaghan, Judy Teale, Christine Wells
* Non-PIs with who have used resources to study related members of this paradigm group include: Roland Lang, Ulrich Maus, Gunnar Nilsson, Kenneth Rock

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about MGL, its carbohydrate ligand(s), and how they interact to mediate cell communication. Further information about MGL can be found in its [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_hum_Ctlect_217&sideMenu=no GBP Molecule Page] in the CFG database.
=== Carbohydrate ligands ===
*mMGL1 binds Lewis X and Lewis A structures, whereas mMGL2 recognizes N-acetylgalactosamine (GalNAc) and galactose, including the O-linked Tn-antigen and TF-antigen <ref name=Tsuiji 2002"/><ref name="Singh 2009"/><Ref name="Napoletano2007"/>
*hMGL binds terminal α- and β-linked GalNAc residues on glycoproteins, glycolipids and bacterial LPS, including Tn antigen and GalNAcβ1-4GlcNAc-R (LDN) antigens <ref name="Suzuki 1996"/><ref name="Van Vliet 2005">van Vliet SJ, van Liempt E, Saeland E, Aarnoudse CA, Appelmelk B, Irimura T, Geijtenbeek TB, Blixt O, Alvarez R, van Die I and van Kooyk Y. 2005. Carbohydrate profiling reveals a distinctive role for the C-type lectin MGL in the recognition of helminth parasites and tumor antigens by dendritic cells. Int Immunol. 17:661-669</ref><ref>van Sorge NM, Bleumink NM, van Vliet SJ, Saeland E, van der Pol WL, van Kooyk Y and van Putten JP. 2009. N-glycosylated proteins and distinct lipooligosaccharide glycoforms of Campylobacter jejuni target the human C-type lectin receptor MGL. Cell Microbiol. 11:1768-1781</ref><ref>Saeland E, van Vliet SJ, Backstrom M, van den Berg VC, Geijtenbeek TB, Meijer GA and van Kooyk Y. 2007. The C-type lectin mgl expressed by dendritic cells detects glycan changes on Muc1 in colon carcinoma. Cancer Immunol Immunother. 56:1225-1236</ref><ref name="Napoletano2007">Napoletano C, Rughetti A, Tarp M.P.A, Coleman J Bennett,E.P, Picco G, Sale P, Denda-Hagai K, Irimura T, Mandel U, Clausen H, Frati L, Taylor-Papadimitriou J, Burchell J, Nuti M. Tumour associated Tn-MUC1 glycoform is internalised througfh the macrophage galactose C-type lectin and delivered to the HLA class I and Class II compartments in dendritic cells. Cancer Research, 2007, 67(17): 8358-8367</ref>.
*hMGL can also bind to STn when presented on a peptide or polyacrylamide backbone.
 

=== Cellular expression of GBP and ligands ===
MGL is expressed on dendritic cells and macrophages. <ref name="Higashi 2002"/><ref name=" van Vliet SJ1200 ">van Vliet SJ, Gringhuis SI, Geijtenbeek TB and van Kooyk Y. 2006. Regulation of effector T cells by antigen-presenting cells via interaction of the C-type lectin MGL with CD45. Nat Immunol. 7:1200-1208</ref>
 
The Tn ligand is expressed by many cancer cells especially breast cancers where it is expressed on more than 90% of breast carcinomas <ref> Sørensen AL, “et al”. Chemoenzymatically synthesized multimeric Tn/STn MUC1 glycopeptides elicit cancer-specific anti-MUC1 antibody responses and override tolerance. “Glycobiology” 16, 96-107 (2006) </ref>. although STn is also expressed by carcinomas, especially colorectal and in 25-30% of breast cancers.

=== Biosynthesis of ligands ===
The Tn ligand can be expressed in cervical cancer due to mutations in Cosmc <ref> Ju T, “et al”. Human tumor antigens Tn and sialyl Tn arise from mutations in Cosmc “Cancer Research” 68, 1636-1646 (2008) </ref>. a molecular chaperone that is essential for the activity of the T synthase, the glycosyltransferase that catalyses the addition Gal to GalNAcαSer/Thr, forming the T antigen (Galβ1,3GalNAcαSer/Thr).
Although the vast majority of breast cancers express Tn there is no evidence of mutated Cosmc in these cancers therefore another mechanism for the expression of the Tn ligand must be active. Moreover the expression of STn in breast cancer is perfectly correlated with the turning on of the transcription of ST6GalNAc-I <ref> Sewell R, “et al”. The ST6GalNAc-I sialyltransferase localizes throughout the Golgi and is responsible for the synthesis of the tumor-associated sialyl-Tn O-glycan in human breast cancer. “J Biol Chem” 281, 3586-3594 (2006) </ref>.
 

=== Structure ===
[[image:MGL.jpg]] 
MGL is an oligomeric type II transmembrane protein. The CRD of the major subunit of the hepatic asialoglycoprotein receptor has been determined<ref name="Meier2000">Meier, M, Bider, MD, Malashkevich, VN, Spiess, M and Burkhard, P. 2000. Crystal structure of the carbohydrate recognition domain of the H1 subunit of the asialoglycoprotein receptor. J Mol Biol 300:857–865</ref> and the structure of a galatose-binding mutant of mannose-binding protein provides experimental evidence for how galactose- and GalNAc-terminated ligands can bind to the receptor.<ref name="Kolatkar2000">Kolatkar, AR, Leung, AK, Isecke, R, Brossmer, R, Drickamer, K and Weis, WI. 1998. Mechanism of N-acetylgalactosamine binding to a C-type animal lectin carbohydrate-recognition domain. J Biol Chem 273:19502-19508</ref>
 

=== Biological roles of GBP-ligand interaction ===
*MGL is a highly efficient internalization receptor <ref name="Higashi 2002"/><ref>Valladeau J, Duvert-Frances V, Pin JJ, Kleijmeer MJ, Ait-Yahia S, Ravel O, Vincent C, Vega F, Jr., Helms A, Gorman D, Zurawski SM, Zurawski G, Ford J and Saeland S. 2001. Immature human dendritic cells express asialoglycoprotein receptor isoforms for efficient receptor-mediated endocytosis. J Immunol. 167:5767-5774</ref>
*hMGL regulates T-cell receptor mediated signaling and T-cell dependent cytokine responses <ref name=" van Vliet SJ1200 "/>
*mMGL1 promotes adipose tissue inflammation and insulin resistance <ref>Westcott DJ, Delproposto JB, Geletka LM, Wang T, Singer K, Saltiel AR, Lumeng CN. 2009. MGL1 promotes adipose tissue inflammation and insulin resistance by regulating 7/4hi monocytes in obesity. J Exp Med 206: 3143-56</ref>
*mMGL2 promotes enhances both MHC class II and class I presentation antigen in dendritic cells (DCs) <ref>Singh SK, Streng-Ouwehand I, Litjens M, Kalay H, Saeland E, Van Kooyk Y. 2010. Tumour-associated glycan modifications of antigen enhance MGL2 dependent uptake and MHC class I restricted CD8 T cell responses. Int. J. Cancer, in press</ref>

 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=MGL&maxresults=20 CFG database search results for MGL].

=== Glycan profiling ===

 
=== Glycogene microarray ===
Probes for the single human MGL and both mouse MGLs have been included in all versions of the CFG glycogene chip.
 

=== Knockout mouse lines ===
Knockouts for one of the mouse orthologs of MGL were distributed by the CFG and the [https://www.functionalglycomics.org/glycomics/publicdata/phenotyping.jsp phenotype] was analyzed.

=== Glycan array ===
The glycan-binding specificity of [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_GLYCAN_v2_13_11262003 human] and [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_2010 mouse] versions of MGL have been analyzed by glycan array screening <ref name="Van Vliet 2005"/><ref name="Singh 2009"/>. See all glycan array results for MGL [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=mgl&cat=coreh here]. See glycan array results for these related GBPs: [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=mannose%20AND%20receptor%20NOT%20asialoglycoprotein&cat=coreh mannose receptor,] [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=mincle&cat=coreh mincle,] [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=MCL&cat=coreh macrophage C-type lectin (MCL),] and [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=dectin-1&cat=coreh dectin-1.]

== Related GBPs ==
Other C-type lectins on macrophages include the mannose receptor [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=DC-SIGNR&maxresults=20 (CFG data)], mincle <ref>Wells CA, Salvage-Jones JA, Li X, Hitchens K, Butcher S, Murray RZ, Beckhouse AG, Lo YL, Manzanero S, Cobbold C, Schroder K, Ma B, Orr S, Stewart L, Lebus D, Sobieszczuk P, Hume DA, Stow J, Blanchard H, Ashman RB. 2008. The macrophage-inducible C-type lectin, mincle, is an essential component of the innate immune response to Candida albicans. J Immunol 180: 7404-7413</ref> [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=mincle&maxresults=20 (CFG data)], macrophage C- type lectin (MCL) [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=MCL&maxresults=20 (CFG data)], and dectin-1 [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=dectin-1&maxresults=20 (CFG data)].

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Kurt Drickamer, Joyce Taylor-Papadimitriou, Yvette van Kooyk, Irma van Die

Macrophage galactose lectin (MGL)

2011-04-15T07:47:44Z

Kurt Drickamer: /* Biosynthesis of ligands */

Macrophage galactose binding lectin (MGL) is the best studied of the multiple C-type lectins on macrophages <ref name="Kawasaki 1986">Kawasaki T, Ii M, Kozutsumi Y and Yamashina I. 1986. Isolation and characterization of a receptor lectin specific for galactose/N-acetylgalactosamine from macrophages. Carbohydr Res. 151:197-206</ref><ref name="Suzuki 1996">Suzuki N, Yamamoto K, Toyoshima S, Osawa T and Irimura T. 1996. Molecular cloning and expression of cDNA encoding human macrophage C-type lectin. Its unique carbohydrate binding specificity for Tn antigen. J Immunol. 156:128-135</ref>. It is also representative of the subclass of C-type lectins that bind galactose-related sugars. MGL consists of one CRD domain and contains cytoplasmic internalization motifs for endocytosis. No signaling properties have been described yet for MGL. Human MGL (CD301) and rat MGL are encoded by a single gene, whereas mice contain two MGL copies, mMGL-1 and mMGL-2 that differ in carbohydrate specificity <ref name=Tsuiji 2002">Tsuiji M, Fujimori M, Ohashi Y, Higashi N, Onami TM, Hedrick SM and Irimura T. 2002. Molecular cloning and characterization of a novel mouse macrophage C-type lectin, mMGL2, which has a distinct carbohydrate specificity from mMGL1. J Biol Chem. 277:28892-28901</ref><ref name="Singh 2009">Singh SK, Streng-Ouwehand I, Litjens M, Weelij DR, Garca-Vallejo JJ, van Vliet SJ, Saeland E, van Kooyk Y. 2009. Characterization of murine MGL1 and MGL2 C-type lectins: distinct glycan specificities and tumor binding properties. Mol Immunol 46: 1240-1249</ref><ref name="Higashi 2002">Higashi N, Fujioka K, Denda-Nagai K, Hashimoto S, Nagai S, Sato T, Fujita Y, Morikawa A, Tsuiji M, Miyata-Takeuchi M, Sano Y, Suzuki N, Yamamoto K, Matsushima K and Irimura T. 2002. The macrophage C-type lectin specific for galactose/N-acetylgalactosamine is an endocytic receptor expressed on monocyte-derived immature dendritic cells. J Biol Chem. 277:20686-20693</ref>.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
In addition to creating the knockout for the two mouse forms of MGL, PIs have been involved in extensive studies of binding specificity and mechanism of ligand binding as well as the role of the receptor in macrophage signaling.
* PIs working on MGL include: Nicolai Bovin, Kurt Drickamer, Toshisuke Kawasaki, Cheng Liu, Yvette van Kooyk, Hui Wu, Joy Burchell,Joyce Taylor-Papadimitriou
* Non-PIs with who have used CFG resources to study MGL include: Siamon Gordon, Alan Saltiel
* PIs working on MGL-related glycan-binding proteins (GBPs), particularly Mincle, include: Anthony dApice, Joshua Fierer, Rikard Holmdahl, Christopher O'Callaghan, Judy Teale, Christine Wells
* Non-PIs with who have used resources to study related members of this paradigm group include: Roland Lang, Ulrich Maus, Gunnar Nilsson, Kenneth Rock

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about MGL, its carbohydrate ligand(s), and how they interact to mediate cell communication. Further information about MGL can be found in its [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_hum_Ctlect_217&sideMenu=no GBP Molecule Page] in the CFG database.
=== Carbohydrate ligands ===
*mMGL1 binds Lewis X and Lewis A structures, whereas mMGL2 recognizes N-acetylgalactosamine (GalNAc) and galactose, including the O-linked Tn-antigen and TF-antigen <ref name=Tsuiji 2002"/><ref name="Singh 2009"/><Ref name="Napoletano2007"/>
*hMGL binds terminal α- and β-linked GalNAc residues on glycoproteins, glycolipids and bacterial LPS, including Tn antigen and GalNAcβ1-4GlcNAc-R (LDN) antigens <ref name="Suzuki 1996"/><ref name="Van Vliet 2005">van Vliet SJ, van Liempt E, Saeland E, Aarnoudse CA, Appelmelk B, Irimura T, Geijtenbeek TB, Blixt O, Alvarez R, van Die I and van Kooyk Y. 2005. Carbohydrate profiling reveals a distinctive role for the C-type lectin MGL in the recognition of helminth parasites and tumor antigens by dendritic cells. Int Immunol. 17:661-669</ref><ref>van Sorge NM, Bleumink NM, van Vliet SJ, Saeland E, van der Pol WL, van Kooyk Y and van Putten JP. 2009. N-glycosylated proteins and distinct lipooligosaccharide glycoforms of Campylobacter jejuni target the human C-type lectin receptor MGL. Cell Microbiol. 11:1768-1781</ref><ref>Saeland E, van Vliet SJ, Backstrom M, van den Berg VC, Geijtenbeek TB, Meijer GA and van Kooyk Y. 2007. The C-type lectin mgl expressed by dendritic cells detects glycan changes on Muc1 in colon carcinoma. Cancer Immunol Immunother. 56:1225-1236</ref><ref name="Napoletano2007">Napoletano C, Rughetti A, Tarp M.P.A, Coleman J Bennett,E.P, Picco G, Sale P, Denda-Hagai K, Irimura T, Mandel U, Clausen H, Frati L, Taylor-Papadimitriou J, Burchell J, Nuti M. Tumour associated Tn-MUC1 glycoform is internalised througfh the macrophage galactose C-type lectin and delivered to the HLA class I and Class II compartments in dendritic cells. Cancer Research, 2007, 67(17): 8358-8367</ref>.
 
*hMGL can also bind to STn when presented on a peptide or polyacrylamide backbone.

=== Cellular expression of GBP and ligands ===
MGL is expressed on dendritic cells and macrophages. <ref name="Higashi 2002"/><ref name=" van Vliet SJ1200 ">van Vliet SJ, Gringhuis SI, Geijtenbeek TB and van Kooyk Y. 2006. Regulation of effector T cells by antigen-presenting cells via interaction of the C-type lectin MGL with CD45. Nat Immunol. 7:1200-1208</ref>
 
The Tn ligand is expressed by many cancer cells especially breast cancers where it is expressed on more than 90% of breast carcinomas <ref> Sørensen AL, “et al”. Chemoenzymatically synthesized multimeric Tn/STn MUC1 glycopeptides elicit cancer-specific anti-MUC1 antibody responses and override tolerance. “Glycobiology” 16, 96-107 (2006) </ref>. although STn is also expressed by carcinomas, especially colorectal and in 25-30% of breast cancers.

=== Biosynthesis of ligands ===
The Tn ligand can be expressed in cervical cancer due to mutations in Cosmc <ref> Ju T, “et al”. Human tumor antigens Tn and sialyl Tn arise from mutations in Cosmc “Cancer Research” 68, 1636-1646 (2008) </ref>. a molecular chaperone that is essential for the activity of the T synthase, the glycosyltransferase that catalyses the addition Gal to GalNAcαSer/Thr, forming the T antigen (Galβ1,3GalNAcαSer/Thr).
Although the vast majority of breast cancers express Tn there is no evidence of mutated Cosmc in these cancers therefore another mechanism for the expression of the Tn ligand must be active. Moreover the expression of STn in breast cancer is perfectly correlated with the turning on of the transcription of ST6GalNAc-I <ref> Sewell R, “et al”. The ST6GalNAc-I sialyltransferase localizes throughout the Golgi and is responsible for the synthesis of the tumor-associated sialyl-Tn O-glycan in human breast cancer. “J Biol Chem” 281, 3586-3594 (2006) </ref>.
 

=== Structure ===
[[image:MGL.jpg]] 
MGL is an oligomeric type II transmembrane protein. The CRD of the major subunit of the hepatic asialoglycoprotein receptor has been determined<ref name="Meier2000">Meier, M, Bider, MD, Malashkevich, VN, Spiess, M and Burkhard, P. 2000. Crystal structure of the carbohydrate recognition domain of the H1 subunit of the asialoglycoprotein receptor. J Mol Biol 300:857–865</ref> and the structure of a galatose-binding mutant of mannose-binding protein provides experimental evidence for how galactose- and GalNAc-terminated ligands can bind to the receptor.<ref name="Kolatkar2000">Kolatkar, AR, Leung, AK, Isecke, R, Brossmer, R, Drickamer, K and Weis, WI. 1998. Mechanism of N-acetylgalactosamine binding to a C-type animal lectin carbohydrate-recognition domain. J Biol Chem 273:19502-19508</ref>
 

=== Biological roles of GBP-ligand interaction ===
*MGL is a highly efficient internalization receptor <ref name="Higashi 2002"/><ref>Valladeau J, Duvert-Frances V, Pin JJ, Kleijmeer MJ, Ait-Yahia S, Ravel O, Vincent C, Vega F, Jr., Helms A, Gorman D, Zurawski SM, Zurawski G, Ford J and Saeland S. 2001. Immature human dendritic cells express asialoglycoprotein receptor isoforms for efficient receptor-mediated endocytosis. J Immunol. 167:5767-5774</ref>
*hMGL regulates T-cell receptor mediated signaling and T-cell dependent cytokine responses <ref name=" van Vliet SJ1200 "/>
*mMGL1 promotes adipose tissue inflammation and insulin resistance <ref>Westcott DJ, Delproposto JB, Geletka LM, Wang T, Singer K, Saltiel AR, Lumeng CN. 2009. MGL1 promotes adipose tissue inflammation and insulin resistance by regulating 7/4hi monocytes in obesity. J Exp Med 206: 3143-56</ref>
*mMGL2 promotes enhances both MHC class II and class I presentation antigen in dendritic cells (DCs) <ref>Singh SK, Streng-Ouwehand I, Litjens M, Kalay H, Saeland E, Van Kooyk Y. 2010. Tumour-associated glycan modifications of antigen enhance MGL2 dependent uptake and MHC class I restricted CD8 T cell responses. Int. J. Cancer, in press</ref>

 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=MGL&maxresults=20 CFG database search results for MGL].

=== Glycan profiling ===

 
=== Glycogene microarray ===
Probes for the single human MGL and both mouse MGLs have been included in all versions of the CFG glycogene chip.
 

=== Knockout mouse lines ===
Knockouts for one of the mouse orthologs of MGL were distributed by the CFG and the [https://www.functionalglycomics.org/glycomics/publicdata/phenotyping.jsp phenotype] was analyzed.

=== Glycan array ===
The glycan-binding specificity of [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_GLYCAN_v2_13_11262003 human] and [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_2010 mouse] versions of MGL have been analyzed by glycan array screening <ref name="Van Vliet 2005"/><ref name="Singh 2009"/>. See all glycan array results for MGL [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=mgl&cat=coreh here]. See glycan array results for these related GBPs: [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=mannose%20AND%20receptor%20NOT%20asialoglycoprotein&cat=coreh mannose receptor,] [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=mincle&cat=coreh mincle,] [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=MCL&cat=coreh macrophage C-type lectin (MCL),] and [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=dectin-1&cat=coreh dectin-1.]

== Related GBPs ==
Other C-type lectins on macrophages include the mannose receptor [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=DC-SIGNR&maxresults=20 (CFG data)], mincle <ref>Wells CA, Salvage-Jones JA, Li X, Hitchens K, Butcher S, Murray RZ, Beckhouse AG, Lo YL, Manzanero S, Cobbold C, Schroder K, Ma B, Orr S, Stewart L, Lebus D, Sobieszczuk P, Hume DA, Stow J, Blanchard H, Ashman RB. 2008. The macrophage-inducible C-type lectin, mincle, is an essential component of the innate immune response to Candida albicans. J Immunol 180: 7404-7413</ref> [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=mincle&maxresults=20 (CFG data)], macrophage C- type lectin (MCL) [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=MCL&maxresults=20 (CFG data)], and dectin-1 [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=dectin-1&maxresults=20 (CFG data)].

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Kurt Drickamer, Joyce Taylor-Papadimitriou, Yvette van Kooyk, Irma van Die

DC-SIGN

2011-04-15T07:43:38Z

Kurt Drickamer: /* Biosynthesis of ligands */

Dendritic cell-specific intracellular adhesion molecule 3 (ICAM-3)-grabbing nonintegrin (DC-SIGN, CD209) is a C-type lectin that plays roles in both cell-cell and host-pathogen interactions, and thus serves as a model for both processes. This glycan-binding protein (GBP) paradigm also serves as a model for other members of the C-type lectin family expressed on dendritic cells. 
DC-SIGN is a type II membrane protein with a short aminoterminal cytoplasmic tail, a neck region and a single carboxyl terminal carbohydrate recognition domain (CRD)<ref name="Geijtenbeek 2000">Geijtenbeek TB, Torensma R, van Vliet SJ, van Duijnhoven GC, Adema GJ, van Kooyk Y and Figdor CG. 2000. Identification of DC-SIGN, a novel dendritic cell-specific ICAM-3 receptor that supports primary immune responses. Cell. 100:575-585</ref>. The primary structure of the CRD contains conserved residues consistent with classical mannose-specific CRDs <ref name="Feinberg 2001">Feinberg H, Mitchell DA, Drickamer K and Weis WI. 2001. Structural basis for selective recognition of oligosaccharides by DC-SIGN and DC-SIGNR. Science. 294:2163-2166</ref>. Multivalent binding of glycan ligands by DC-SIGN is dependent on correct organization and presentation of the CRDs at the neck domains, which are crucial for tetramerization of DC-SIGN <ref>Yu QD, Oldring AP, Powlesland AS, Tso CK, Yang C, Drickamer K and Taylor ME. 2009. Autonomous tetramerization domains in the glycan-binding receptors DC-SIGN and DC-SIGNR. J Mol Biol. 387:1075-1080</ref>. The cytoplasmic tail of DC-SIGN contains internalization motifs involved in the ligand-induced internalization of DC-SIGN <ref>Engering A, Geijtenbeek TB, van Vliet SJ, Wijers M, van Liempt E, Demaurex N, Lanzavecchia A, Fransen J, Figdor CG, Piguet V and van Kooyk Y. 2002. The dendritic cell-specific adhesion receptor DC-SIGN internalizes antigen for presentation to T cells. J Immunol. 168:2118-2126</ref>, and can activate signaling pathways <ref>Caparros E, Munoz P, Sierra-Filardi E, Serrano-Gomez D, Puig-Kroger A, Rodriguez-Fernandez JL, Mellado M, Sancho J, Zubiaur M and Corbi AL. 2006. DC-SIGN ligation on dendritic cells results in ERK and PI3k activation and modulates cytokine production. Blood. 107:3950-3958</ref><ref>Gringhuis SI, den Dunnen J, Litjens M, van Het Hof B, van Kooyk Y and Geijtenbeek TB. 2007. C-type lectin DC-SIGN modulates toll-like receptor signaling via raf-1 kinase-dependent acetylation of transcription factor NF-kb. Immunity. 26:605-616</ref><ref>Gringhuis SI, den Dunnen J, Litjens M, van der Vlist M and Geijtenbeek TB. 2009. Carbohydrate-specific signaling through the DC-SIGN signalosome tailors immunity to ''Mycobacterium tuberculosis'', HIV-1 and ''Helicobacter pylori''. Nat Immunol. 10:1081-1088</ref>.
In mice several DC-SIGN-related proteins have been identified (SIGNR1-SIGNR8) <ref>Powlesland AS, Ward EM, Sadhu SK, Guo Y, Taylor ME and Drickamer K. 2006. Widely divergent biochemical properties of the complete set of mouse DC-SIGN-related proteins. J Biol Chem. 281:20440-20449</ref>.

== CFG Participating Investigators contributing to the understanding of this paradigm ==

Many investigators, both CFG Participating Investigators (PIs) and non-PIs using CFG resources, have led extensive studies on DC-SIGN, particularly regarding structure-function relationships, interactions with pathogens, and signaling functions in dendritic cells.
* PIs working on DC-SIGN include: Pedro Bonay, Angel Corbi, Kurt Drickamer, Juan Garcia-Vallejo, Donald Harn, Kayo Inaba, Benhur Lee, Olivier Neyrolles, Irma van Die, Yvette van Kooyk, William Weis, Martin Wild
* Non-PIs who have used CFG resources to study DC-SIGN include: Brigitte Gicquel, Arne Skerra, Ralph Steinman

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about DC-SIGN, its carbohydrate ligand(s), and how they interact to mediate cell communication. Further information about DC-SIGN can be found in its [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_hum_Ctlect_00121&sideMenu=no GBP Molecule Page] in the CFG database.
=== Carbohydrate ligands ===
DC-SIGN recognizes both internal branched mannose residues as well as terminal di-mannoses, α1-3 and α1-4 fucosylated glycan structures and certain N-aceltylglucosamine containing molecules on self proteins and/or pathogens <ref name="Feinberg 2001"/><ref name="Guo 2004">Guo Y, Feinberg H, Conroy E, Mitchell DA, Alvarez R, Blixt O, Taylor ME, Weis WI and Drickamer K. 2004. Structural basis for distinct ligand-binding and targeting properties of the receptors DC-SIGN and DC-SIGNR. Nat Struct Mol Biol. 11:591-598</ref><ref>Mitchell DA, Fadden AJ and Drickamer K. 2001. A novel mechanism of carbohydrate recognition by the C-type lectins DC-SIGN and DC-SIGNR. Subunit organization and binding to multivalent ligands. J Biol Chem. 276:28939-28945</ref><ref name="Liempt 2006">van Liempt E, Bank CM, Mehta P, Garcia-Vallejo JJ, Kawar ZS, Geyer R, Alvarez RA, Cummings RD, Kooyk Y and van Die I. 2006. Specificity of DC-SIGN for mannose- and fucose-containing glycans. FEBS Lett. 580:6123-6131</ref> 
''Endogenous ligands include''
*Lewis blood group antigens LeX, LeA, LeY and LeB <ref>Bogoevska V, Horst A, Klampe B, Lucka L, Wagener C and Nollau P. 2006. CEACAM1, an adhesion molecule of human granulocytes, is fucosylated by fucosyltransferase IX and interacts with DC-SIGN of dendritic cells via Lewis X residues. Glycobiology. 16:197-209</ref><ref>Bogoevska V, Nollau P, Lucka L, Grunow D, Klampe B, Uotila LM, Samsen A, Gahmberg CG and Wagener C. 2007. DC-SIGN binds ICAM-3 isolated from peripheral human leukocytes through Lewis X residues. Glycobiology. 17:324-333</ref><ref name="Garcia 2008">Garcia-Vallejo JJ, van Liempt E, da Costa Martins P, Beckers C, van het Hof B, Gringhuis SI, Zwaginga JJ, van Dijk W, Geijtenbeek TB, van Kooyk Y and van Die I. 2008. DC-SIGN mediates adhesion and rolling of dendritic cells on primary human umbilical vein endothelial cells through Lewis Y antigen expressed on ICAM-2. Mol Immunol. 45:2359-2369</ref><ref>Naarding MA, Ludwig IS, Groot F, Berkhout B, Geijtenbeek TB, Pollakis G and Paxton WA. 2005. Lewis x component in human milk binds DC-SIGN and inhibits HIV-1 transfer to CD4+ t lymphocytes. J Clin Invest. 115:3256-3264</ref><ref name="Nonaka 2008">Nonaka M, Ma BY, Murai R, Nakamura N, Baba M, Kawasaki N, Hodohara K, Asano S and Kawasaki T. 2008. Glycosylation-dependent interactions of C-type lectin DC-SIGN with colorectal tumor-associated Lewis glycans impair the function and differentiation of monocyte-derived dendritic cells. J Immunol. 180:3347-3356</ref> 
''Glycan ligands from pathogens include''
*''Mycobacterium tuberculosis'' lipoarabinomannan (ManLAM) and hexamannosylated phosphatidylinositol mannoside PIM6 <ref>Maeda N, Nigou J, Herrmann JL, Jackson M, Amara A, Lagrange PH, Puzo G, Gicquel B and Neyrolles O. 2003. The cell surface receptor DC-SIGN discriminates between mycobacterium species through selective recognition of the mannose caps on lipoarabinomannan. J Biol Chem. 278:5513-5516</ref><ref>Driessen NN, Ummels R, Maaskant JJ, Gurcha SS, Besra GS, Ainge GD, Larsen DS, Painter GF, Vandenbroucke-Grauls CM, Geurtsen J and Appelmelk BJ. 2009. Role of phosphatidylinositol mannosides in the interaction between mycobacteria and DC-SIGN. Infect Immun. 77:4538-4547</ref>
*''Schistosoma mansoni'' glycans LeX, GalNAcβ1-4(Fucα1-3)GlcNAc-R (LDNF) and Fucα1-3Galβ1-4(Fucα1-3)GlcNAc-R (pseudo-LeY) <ref>van Die I, van Vliet SJ, Nyame AK, Cummings RD, Bank CM, Appelmelk B, Geijtenbeek TB and van Kooyk Y. 2003. The dendritic cell-specific C-type lectin DC-SIGN is a receptor for ''Schistosoma mansoni'' egg antigens and recognizes the glycan antigen Lewis x. Glycobiology. 13:471-478</ref><ref>Meyer S, van Liempt E, Imberty A, van Kooyk Y, Geyer H, Geyer R and van Die I. 2005. DC-SIGN mediates binding of dendritic cells to authentic pseudo-Lewis Y glycolipids of ''Schistosoma mansoni'' cercariae, the first parasite-specific ligand of DC-SIGN. J Biol Chem. 280:37349-37359</ref>
*Virus-associated high-mannose type glycans <ref>Feinberg H, Castelli R, Drickamer K, Seeberger PH and Weis WI. 2007. Multiple modes of binding enhance the affinity of DC-SIGN for high mannose N-linked glycans found on viral glycoproteins. J Biol Chem. 282:4202-4209</ref><ref>Lozach PY, Lortat-Jacob H, de Lacroix de Lavalette A, Staropoli I, Foung S, Amara A, Houles C, Fieschi F, Schwartz O, Virelizier JL, Arenzana-Seisdedos F and Altmeyer R. 2003. DC-SIGN and L-SIGN are high affinity binding receptors for hepatitis c virus glycoprotein E2. J Biol Chem. 278:20358-20366</ref>
*''Candida albicans'' N-linked mannan <ref>Cambi A, Netea MG, Mora-Montes HM, Gow NA, Hato SV, Lowman DW, Kullberg BJ, Torensma R, Williams DL and Figdor CG. 2008. Dendritic cell interaction with ''Candida albicans'' critically depends on N-linked mannan. J Biol Chem. 283:20590-20599</ref>
*''Escherichia coli'' K12 ''N''-acetylglucosamine (GlcNAc) residues within core LPS <ref name="Zhang 2006">Zhang P, Snyder S, Feng P, Azadi P, Zhang S, Bulgheresi S, Sanderson KE, He J, Klena J and Chen T. 2006. Role of N-acetylglucosamine within core lipopolysaccharide of several species of gram-negative bacteria in targeting DC-SIGN (CD209). J Immunol. 177:4002-4011</ref>
*''Neisseria meningitides'' GlcNAcβ1-3Galβ1-4Glc-R oligosaccharide of lgtB outer core LPS <ref name="Steeghs 2006">Steeghs L, van Vliet SJ, Uronen-Hansson H, van Mourik A, Engering A, Sanchez-Hernandez M, Klein N, Callard R, van Putten JP, van der Ley P, van Kooyk Y and van de Winkel JG. 2006. ''Neisseria meningitidis'' expressing Lgtb lipopolysaccharide targets DC-SIGN and modulates dendritic cell function. Cell Microbiol. 8:316-325</ref>
*''Helicobacter pylori'' LPS-associated LeX glycan antigens <ref name="Bergman 2004">Bergman MP, Engering A, Smits HH, van Vliet SJ, van Bodegraven AA, Wirth HP, Kapsenberg ML, Vandenbroucke-Grauls CM, van Kooyk Y and Appelmelk BJ. 2004. ''Helicobacter py''lori modulates the T helper cell 1/T helper cell 2 balance through phase-variable interaction between lipopolysaccharide and DC-SIGN. J Exp Med. 200:979-990</ref>
 
=== Cellular expression of GBP and ligands ===

DC-SIGN is expressed on dendritic cells and dendritic cell-like macrophages. Pathogens expressing DC-SIGN ligands include: ''Mycobacterium tuberculosis'', ''Schistosoma mansoni'', ''Candida albicans'', ''Escherichia coli'', ''Neisseria meningitides'', ''Helicobacter pylori'', and others (see above).
 

=== Biosynthesis of ligands ===
Endogenous glycans 
The fucosyltransferase responsible in humans and mice for LeX biosynthesis is Fuc-TIV. T-cells also express Fuc-TVII, but this transferase is specific for sialyl-LeX <ref name="Niemela 1998">Niemela R, Natunen J, Majuri ML, Maaheimo H, Helin J, Lowe JB, et al. Complementary acceptor and site specificities of Fuc-TIV and Fuc-TVII allow effective biosynthesis of sialyl-TriLex and related polylactosamines present on glycoprotein counterreceptors of selectins. J Biol Chem. 1998 Feb 13;273(7):4021-6</ref>.
 
Glycans on viruses 
High mannose oligosaccharides on viral envelope proteins that are ligands for DC-SIGN result from incomplete processing of glycans in the pathway for biosynthesis of complex N-linked glycans ([http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/geMolecule.jsp?slideNumber=default GT Database]).
 
Glycans on bacteria 
The biosynthesis pathways for the bacterial lipopolysaccharides have been extensively studied and the gene families responsible for the expression of different glycan sequences have been characterized.<ref name”Raetz2002”>Raetz CR and Whitfield C (2002) Lipopolysaccharide endotoxins. Annu. Rev. Biochem. 71, 635-700</ref>
 
The mycobacterial transferases for synthesis of the lipo-arabinomannan (LAM) core and the extended ManLAM structures have been characterized.<ref name”Tam2009”>Tam, P-H and Lowary, TL (2009) Recent advances in mycobacterial cell wall glycan biosynthesis. Cur. Opin Struct. Biol. 13, 618-625</ref>
 
Glycans on fungi 
Biosynthesis mannans on fungi has been well studied in a number of species. For example, in the yeast S. cerevisiae, the KRE2/MNT1 genes encode mannosyltransferases that synthesize both N- and O-linked mannans.<ref name”Lussier1999”>Lussier, M, Sdicu, A-M and Bussey, H (1999) The KTR and MNN1 mannosyltransferase families of Saccharomyces cerevisiae. Biochim. Biophys. Acta 1426, 323-334</ref>
 
Glycans on parasites 
Some data give insight in the biosynthesis of DC-SIGN ligands in parasitic helminths. In Schistosoma mansoni <ref>DeBose-Boyd R, Nyame AK, Cummings RD. 1996. Schistosoma mansoni: characterization of an α1-3 fucosyltransferase in adult parasites. Exp Parasitol. 82: 1-10</ref><ref>Marques Jr ET Jr, Ichikawa Y, Strand M, August JT, Hart GW, Schnaar RL. 2001. Fucosyltransferases in ''Schistosoma mansoni'' development. Glycobiology 11: 249-59</ref> and ''Haemonchus contortus'' <ref>DeBose-Boyd RA, Nyame AK, Jasmer DP, Cummings RD. 1998. The ruminant parasite ''Haemonchus contortus'' expresses an α1,3-fucosyltransferase capable of synthesizing the Lewis x and sialyl Lewis x antigens. Glycoconjugate J. 15: 789-98</ref> α1,3-fucosyltransferases have been identified, which may be involved in generation of Galβ1-4(Fucα1-3)GlcNAc-R (Lewis X), and/or GalNAcβ1-4(Fucα1-3)GlcNAc-R (LDNF). Combined transcriptome (putative glycosyltransferase genes) and glycome analyses of Schistosoma revealed that female schistosomes synthesize preferably terminal LacNAc and Lewis X, whereas male worms synthesize more LDN/LDNF antigens <ref>Hokke CH, Fitzpatrick JM and Hoffmann KF. 2007. Integrating transcriptome, proteome and glycome analyses of Schistosoma biology. Trends in Parasitology 23: 165-174</ref>.

=== Structure ===
[[image:DC-SIGN_4.jpg]] 
Crystal structures of the CRD of DC-SIGN bound to a mannose-containing oligosaccharide and lacto-N-fucopentaose have been analyzed.<ref name="Feinberg 2001"/><ref name="Guo 2004"/> The first structure can be used to model the binding of the outer portion of a high mannose oligosaccharide and the second structure shows how the Lewisx trisaccharide fits into the binding site. The high mannose oligosaccharide makes extensive interactions in an extended binding site, while the more rigid Lewisx oligosaccharide binds primarily through the fucose residues, with some additional stabilizing interactions with the galactose. The overall structure of the tetrameric extracellular domain has been deduced from crystal structures of the repeats in the neck domain of the related protein DC-SIGNR (L-SIGN)<ref name="Feinberg 2009">Feinberg, H, Tso, CKW, Taylor, ME, Drickamer, K and Weis, WI. 2009. Segmented helical structure of the neck region of the glycan-binding receptor DC-SIGNR. J Mol Biol 394:613-620</ref> and oligomeric C-terminal fragments of DC-SIGN that contain the CRD<ref name="Feinberg 2005">Feinberg, H, Guo, Y, Mitchell, DA, Drickamer, K and Weis, WI. 2005. Extended neck regions stabilze tetramers of the receptors DC-SIGN and DC-SIGNR. J Biol Chem 280:1327-1335</ref>.
 

=== Biological roles of GBP-ligand interaction ===
''Biological roles for DC-SIGN include'':
*DC-SIGN mediates interactions between dendritic cells (DCs) and resting T cells <ref name="Geijtenbeek 2000"/> and between DCs and neutrophils <ref>van Gisbergen KP, Sanchez-Hernandez M, Geijtenbeek TB and van Kooyk Y. 2005. Neutrophils mediate immune modulation of dendritic cells through glycosylation-dependent interactions between MAC-1 and DC-SIGN. J Exp Med. 201:1281-1292</ref>.
*DC-SIGN contributes to adhesion and rolling of DCs on primary human umbilical vein endothelial cells <ref>Geijtenbeek TB, Krooshoop DJ, Bleijs DA, van Vliet SJ, van Duijnhoven GC, Grabovsky V, Alon R, Figdor CG and van Kooyk Y. 2000. DC-SIGN-ICAM-2 interaction mediates dendritic cell trafficking. Nat Immunol. 1:353-357</ref><ref name="Garcia 2008"/>
*interactions of DC-SIGN with Lewis antigens on colorectal tumor cells impair the function and differentiation of dendritic cells <ref name="Nonaka 2008"/>
*DC-SIGN can mediate bacterial adherence and phagocytosis <ref name="Zhang 2006"/>.
*viruses target DC-SIGN to promote infection and spread to cells <ref>Geijtenbeek TB, Kwon DS, Torensma R, van Vliet SJ, van Duijnhoven GC, Middel J, Cornelissen IL, Nottet HS, KewalRamani VN, Littman DR, Figdor CG and van Kooyk Y. 2000. DC-SIGN, a dendritic cell-specific HIV-1-binding protein that enhances trans-infection of T cells. Cell. 100:587-597</ref><ref>Navarro-Sanchez E, Altmeyer R, Amara A, Schwartz O, Fieschi F, Virelizier JL, Arenzana-Seisdedos F and Despres P. 2003. Dendritic-cell-specific ICAM3-grabbing non-integrin is essential for the productive infection of human dendritic cells by mosquito-cell-derived dengue viruses. EMBO Rep. 4:723-728</ref><ref>Simmons G, Reeves JD, Grogan CC, Vandenberghe LH, Baribaud F, Whitbeck JC, Burke E, Buchmeier MJ, Soilleux EJ, Riley JL, Doms RW, Bates P and Pohlmann S. 2003. DC-SIGN and DC-SIGNR bind Ebola glycoproteins and enhance infection of macrophages and endothelial cells. Virology. 305:115-123</ref><ref>Hodges A, Sharrocks K, Edelmann M, Baban D, Moris A, Schwartz O, Drakesmith H, Davies K, Kessler B, McMichael A and Simmons A. 2007. Activation of the lectin DC-SIGN induces an immature dendritic cell phenotype triggering Rho-GTPase activity required for HIV-1 replication. Nat Immunol. 8:569-577</ref>
*activation of DC-SIGN by pathogens can contribute to T helper type 1 (Th)1 cell activity <ref name="Steeghs 2006"/><ref>van Stijn CM, Meyer S, van den Broek M, Bruijns SC, van Kooyk Y, Geyer R and van Die I. 2010. ''Schistosoma mansoni'' worm glycolipids induce an inflammatory phenotype in human dendritic cells by cooperation of TLR4 and DC-SIGN. Mol Immunol. 47:1544-1552</ref>
*some pathogens target DC-SIGN to suppress Th1 cell development <ref name="Bergman 2004"/><ref>Geijtenbeek TB, Van Vliet SJ, Koppel EA, Sanchez-Hernandez M, Vandenbroucke-Grauls CM, Appelmelk B and Van Kooyk Y. 2003. Mycobacteria target DC-SIGN to suppress dendritic cell function. J Exp Med. 197:7-17</ref>
* the murine DC-SIGN homologue SIGNR3 contributes to early host defense against Mycobacterium tuberculosis <ref>Tanne A, Ma B, Boudou F, Tailleux L, Botella H, Badell E, Levillain F, Taylor ME, Drickamer K, Nigou J, Dobos KM, Puzo G, Vestweber D, Wild MK, Marcinko M, Sobieszczuk P, Stewart L, Lebus D, Gicquel B, Neyrolles O. 2009. A murine DC-SIGN homologue contributes to early host defense against ''Mycobacterium tub''erculosis. J Exp Med 206: 2205-2220</ref>
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=DC-SIGN&maxresults=20 CFG database search results for DC-SIGN].

=== Glycan profiling ===
LeX antigens, which are potential ligands for DC-SIGN, have been identified by the Analytical Glycotechnology Core in the following cells of the immune system:
 
 
Human:
[http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=B-Cells&operation=refine&templateKey=2&12=CellType&submit=submit B-cells], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=Basophils&operation=refine&templateKey=2&12=CellType&submit=submit basophils], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=Dendritic+Cells&operation=refine&templateKey=2&12=CellType&submit=submit dendritic cells], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=Eosinophils+&operation=refine&templateKey=2&12=CellType&submit=submit eosinophils], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=Human+Dermal+Lymphatic+Endothelial+Cells+%28HDLEC%29+&operation=refine&templateKey=2&12=CellType&submit=submit human dermal lymphatic endothelial cells], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=Macrophages&operation=refine&templateKey=2&12=CellType&submit=submit macrophages], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=Mast+Cells&operation=refine&templateKey=2&12=CellType&submit=submit mast cells], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=Monocytes&operation=refine&templateKey=2&12=CellType&submit=submit monocytes], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=Natural+Killer+Cells&operation=refine&templateKey=2&12=CellType&submit=submit natural killer cells], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=Neutrophils&operation=refine&templateKey=2&12=CellType&submit=submit neutrophils], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=Peripheral+Blood+Mononuclear+Cells+%28PBMC%29&operation=refine&templateKey=2&12=CellType&submit=submit peripheral blood mononuclear cells], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=Peripheral+Blood+Mononuclear+Cells+%28PBMC%29&operation=refine&templateKey=2&12=CellType&submit=submit T cells]
 
 
Mouse:
[http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Mouse&15=&10=&9=B1+Cells&operation=refine&templateKey=2&12=CellType&submit=submit B1 cells], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Mouse&15=&10=&9=B1+Cells&operation=refine&templateKey=2&12=CellType&submit=submit B2 cells], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Mouse&15=&10=&9=Cytokine-induced+killer+%28CIK%29+cells&operation=refine&templateKey=2&12=CellType&submit=submit cytokine induced killer cells], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Mouse&15=&10=&9=Eosinophils+&operation=refine&templateKey=2&12=CellType&submit=submit eosinophils], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Mouse&15=&10=&9=Macrophages&operation=refine&templateKey=2&12=CellType&submit=submit macrophages]
 
 
([http://www.functionalglycomics.org/glycomics/publicdata/glycoprofiling-new.jsp all Analytical Glycotechnology Core data])
 
 
T-Cells, which would be the most relevant interacting partner, contain substantial levels of LeX in humans.

=== Glycogene microarray ===
Probes for human DC-SIGN have been included in all versions of the CFG glycogene chip.
 

=== Knockout mouse lines ===

Knockout mice for three potential DC-SIGN orthologues ([https://www.functionalglycomics.org/static/consortium/resources/DataCoreFdc.shtml DC-SIGN], [https://www.functionalglycomics.org/static/consortium/resources/DataCoreFsr1.shtml SIGNR1], and [https://www.functionalglycomics.org/static/consortium/resources/DataCoreFsr3.shtml SIGNR3]) were created by the CFG and distributed to PIs, and their [http://www.functionalglycomics.org/glycomics/publicdata/phenotyping.jsp phenotypes] were analyzed.

=== Glycan array ===

Glycan array analysis <ref name="Guo 2004"/><ref name="Liempt 2006"/>and synthetic oligosaccharides were used to elucidate DC-SIGN [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_GLYCAN_v2_52_06122003 glycan-binding specificity] and analyze the mechanism of specific glycan binding. See all glycan array results for [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=dc-sign&cat=coreh DC-SIGN here]. See glycan array screening results for these related GBPs: [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=langerin&cat=coreh langerin,] [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=DCIR&cat=coreh DCIR,] and [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=DC-SIGNR&cat=coreh DC-SIGNR.]

== Related GBPs ==
Other dendritic cell lectins include langerin [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=langerin&maxresults=20 (CFG data)], DCIR [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=DCIR&maxresults=20 (CFG data)], and DCAR. Paralogs on other cells include DC-SIGNR [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=DC-SIGNR&maxresults=20 (CFG data)].

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Kurt Drickamer, Irma van Die, Yvette van Kooyk

DC-SIGN

2011-04-15T07:41:54Z

Kurt Drickamer: /* Glycan profiling */

Dendritic cell-specific intracellular adhesion molecule 3 (ICAM-3)-grabbing nonintegrin (DC-SIGN, CD209) is a C-type lectin that plays roles in both cell-cell and host-pathogen interactions, and thus serves as a model for both processes. This glycan-binding protein (GBP) paradigm also serves as a model for other members of the C-type lectin family expressed on dendritic cells. 
DC-SIGN is a type II membrane protein with a short aminoterminal cytoplasmic tail, a neck region and a single carboxyl terminal carbohydrate recognition domain (CRD)<ref name="Geijtenbeek 2000">Geijtenbeek TB, Torensma R, van Vliet SJ, van Duijnhoven GC, Adema GJ, van Kooyk Y and Figdor CG. 2000. Identification of DC-SIGN, a novel dendritic cell-specific ICAM-3 receptor that supports primary immune responses. Cell. 100:575-585</ref>. The primary structure of the CRD contains conserved residues consistent with classical mannose-specific CRDs <ref name="Feinberg 2001">Feinberg H, Mitchell DA, Drickamer K and Weis WI. 2001. Structural basis for selective recognition of oligosaccharides by DC-SIGN and DC-SIGNR. Science. 294:2163-2166</ref>. Multivalent binding of glycan ligands by DC-SIGN is dependent on correct organization and presentation of the CRDs at the neck domains, which are crucial for tetramerization of DC-SIGN <ref>Yu QD, Oldring AP, Powlesland AS, Tso CK, Yang C, Drickamer K and Taylor ME. 2009. Autonomous tetramerization domains in the glycan-binding receptors DC-SIGN and DC-SIGNR. J Mol Biol. 387:1075-1080</ref>. The cytoplasmic tail of DC-SIGN contains internalization motifs involved in the ligand-induced internalization of DC-SIGN <ref>Engering A, Geijtenbeek TB, van Vliet SJ, Wijers M, van Liempt E, Demaurex N, Lanzavecchia A, Fransen J, Figdor CG, Piguet V and van Kooyk Y. 2002. The dendritic cell-specific adhesion receptor DC-SIGN internalizes antigen for presentation to T cells. J Immunol. 168:2118-2126</ref>, and can activate signaling pathways <ref>Caparros E, Munoz P, Sierra-Filardi E, Serrano-Gomez D, Puig-Kroger A, Rodriguez-Fernandez JL, Mellado M, Sancho J, Zubiaur M and Corbi AL. 2006. DC-SIGN ligation on dendritic cells results in ERK and PI3k activation and modulates cytokine production. Blood. 107:3950-3958</ref><ref>Gringhuis SI, den Dunnen J, Litjens M, van Het Hof B, van Kooyk Y and Geijtenbeek TB. 2007. C-type lectin DC-SIGN modulates toll-like receptor signaling via raf-1 kinase-dependent acetylation of transcription factor NF-kb. Immunity. 26:605-616</ref><ref>Gringhuis SI, den Dunnen J, Litjens M, van der Vlist M and Geijtenbeek TB. 2009. Carbohydrate-specific signaling through the DC-SIGN signalosome tailors immunity to ''Mycobacterium tuberculosis'', HIV-1 and ''Helicobacter pylori''. Nat Immunol. 10:1081-1088</ref>.
In mice several DC-SIGN-related proteins have been identified (SIGNR1-SIGNR8) <ref>Powlesland AS, Ward EM, Sadhu SK, Guo Y, Taylor ME and Drickamer K. 2006. Widely divergent biochemical properties of the complete set of mouse DC-SIGN-related proteins. J Biol Chem. 281:20440-20449</ref>.

== CFG Participating Investigators contributing to the understanding of this paradigm ==

Many investigators, both CFG Participating Investigators (PIs) and non-PIs using CFG resources, have led extensive studies on DC-SIGN, particularly regarding structure-function relationships, interactions with pathogens, and signaling functions in dendritic cells.
* PIs working on DC-SIGN include: Pedro Bonay, Angel Corbi, Kurt Drickamer, Juan Garcia-Vallejo, Donald Harn, Kayo Inaba, Benhur Lee, Olivier Neyrolles, Irma van Die, Yvette van Kooyk, William Weis, Martin Wild
* Non-PIs who have used CFG resources to study DC-SIGN include: Brigitte Gicquel, Arne Skerra, Ralph Steinman

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about DC-SIGN, its carbohydrate ligand(s), and how they interact to mediate cell communication. Further information about DC-SIGN can be found in its [http://www.functionalglycomics.org/glycomics/molecule/jsp/viewGbpMolecule.jsp?gbpId=cbp_hum_Ctlect_00121&sideMenu=no GBP Molecule Page] in the CFG database.
=== Carbohydrate ligands ===
DC-SIGN recognizes both internal branched mannose residues as well as terminal di-mannoses, α1-3 and α1-4 fucosylated glycan structures and certain N-aceltylglucosamine containing molecules on self proteins and/or pathogens <ref name="Feinberg 2001"/><ref name="Guo 2004">Guo Y, Feinberg H, Conroy E, Mitchell DA, Alvarez R, Blixt O, Taylor ME, Weis WI and Drickamer K. 2004. Structural basis for distinct ligand-binding and targeting properties of the receptors DC-SIGN and DC-SIGNR. Nat Struct Mol Biol. 11:591-598</ref><ref>Mitchell DA, Fadden AJ and Drickamer K. 2001. A novel mechanism of carbohydrate recognition by the C-type lectins DC-SIGN and DC-SIGNR. Subunit organization and binding to multivalent ligands. J Biol Chem. 276:28939-28945</ref><ref name="Liempt 2006">van Liempt E, Bank CM, Mehta P, Garcia-Vallejo JJ, Kawar ZS, Geyer R, Alvarez RA, Cummings RD, Kooyk Y and van Die I. 2006. Specificity of DC-SIGN for mannose- and fucose-containing glycans. FEBS Lett. 580:6123-6131</ref> 
''Endogenous ligands include''
*Lewis blood group antigens LeX, LeA, LeY and LeB <ref>Bogoevska V, Horst A, Klampe B, Lucka L, Wagener C and Nollau P. 2006. CEACAM1, an adhesion molecule of human granulocytes, is fucosylated by fucosyltransferase IX and interacts with DC-SIGN of dendritic cells via Lewis X residues. Glycobiology. 16:197-209</ref><ref>Bogoevska V, Nollau P, Lucka L, Grunow D, Klampe B, Uotila LM, Samsen A, Gahmberg CG and Wagener C. 2007. DC-SIGN binds ICAM-3 isolated from peripheral human leukocytes through Lewis X residues. Glycobiology. 17:324-333</ref><ref name="Garcia 2008">Garcia-Vallejo JJ, van Liempt E, da Costa Martins P, Beckers C, van het Hof B, Gringhuis SI, Zwaginga JJ, van Dijk W, Geijtenbeek TB, van Kooyk Y and van Die I. 2008. DC-SIGN mediates adhesion and rolling of dendritic cells on primary human umbilical vein endothelial cells through Lewis Y antigen expressed on ICAM-2. Mol Immunol. 45:2359-2369</ref><ref>Naarding MA, Ludwig IS, Groot F, Berkhout B, Geijtenbeek TB, Pollakis G and Paxton WA. 2005. Lewis x component in human milk binds DC-SIGN and inhibits HIV-1 transfer to CD4+ t lymphocytes. J Clin Invest. 115:3256-3264</ref><ref name="Nonaka 2008">Nonaka M, Ma BY, Murai R, Nakamura N, Baba M, Kawasaki N, Hodohara K, Asano S and Kawasaki T. 2008. Glycosylation-dependent interactions of C-type lectin DC-SIGN with colorectal tumor-associated Lewis glycans impair the function and differentiation of monocyte-derived dendritic cells. J Immunol. 180:3347-3356</ref> 
''Glycan ligands from pathogens include''
*''Mycobacterium tuberculosis'' lipoarabinomannan (ManLAM) and hexamannosylated phosphatidylinositol mannoside PIM6 <ref>Maeda N, Nigou J, Herrmann JL, Jackson M, Amara A, Lagrange PH, Puzo G, Gicquel B and Neyrolles O. 2003. The cell surface receptor DC-SIGN discriminates between mycobacterium species through selective recognition of the mannose caps on lipoarabinomannan. J Biol Chem. 278:5513-5516</ref><ref>Driessen NN, Ummels R, Maaskant JJ, Gurcha SS, Besra GS, Ainge GD, Larsen DS, Painter GF, Vandenbroucke-Grauls CM, Geurtsen J and Appelmelk BJ. 2009. Role of phosphatidylinositol mannosides in the interaction between mycobacteria and DC-SIGN. Infect Immun. 77:4538-4547</ref>
*''Schistosoma mansoni'' glycans LeX, GalNAcβ1-4(Fucα1-3)GlcNAc-R (LDNF) and Fucα1-3Galβ1-4(Fucα1-3)GlcNAc-R (pseudo-LeY) <ref>van Die I, van Vliet SJ, Nyame AK, Cummings RD, Bank CM, Appelmelk B, Geijtenbeek TB and van Kooyk Y. 2003. The dendritic cell-specific C-type lectin DC-SIGN is a receptor for ''Schistosoma mansoni'' egg antigens and recognizes the glycan antigen Lewis x. Glycobiology. 13:471-478</ref><ref>Meyer S, van Liempt E, Imberty A, van Kooyk Y, Geyer H, Geyer R and van Die I. 2005. DC-SIGN mediates binding of dendritic cells to authentic pseudo-Lewis Y glycolipids of ''Schistosoma mansoni'' cercariae, the first parasite-specific ligand of DC-SIGN. J Biol Chem. 280:37349-37359</ref>
*Virus-associated high-mannose type glycans <ref>Feinberg H, Castelli R, Drickamer K, Seeberger PH and Weis WI. 2007. Multiple modes of binding enhance the affinity of DC-SIGN for high mannose N-linked glycans found on viral glycoproteins. J Biol Chem. 282:4202-4209</ref><ref>Lozach PY, Lortat-Jacob H, de Lacroix de Lavalette A, Staropoli I, Foung S, Amara A, Houles C, Fieschi F, Schwartz O, Virelizier JL, Arenzana-Seisdedos F and Altmeyer R. 2003. DC-SIGN and L-SIGN are high affinity binding receptors for hepatitis c virus glycoprotein E2. J Biol Chem. 278:20358-20366</ref>
*''Candida albicans'' N-linked mannan <ref>Cambi A, Netea MG, Mora-Montes HM, Gow NA, Hato SV, Lowman DW, Kullberg BJ, Torensma R, Williams DL and Figdor CG. 2008. Dendritic cell interaction with ''Candida albicans'' critically depends on N-linked mannan. J Biol Chem. 283:20590-20599</ref>
*''Escherichia coli'' K12 ''N''-acetylglucosamine (GlcNAc) residues within core LPS <ref name="Zhang 2006">Zhang P, Snyder S, Feng P, Azadi P, Zhang S, Bulgheresi S, Sanderson KE, He J, Klena J and Chen T. 2006. Role of N-acetylglucosamine within core lipopolysaccharide of several species of gram-negative bacteria in targeting DC-SIGN (CD209). J Immunol. 177:4002-4011</ref>
*''Neisseria meningitides'' GlcNAcβ1-3Galβ1-4Glc-R oligosaccharide of lgtB outer core LPS <ref name="Steeghs 2006">Steeghs L, van Vliet SJ, Uronen-Hansson H, van Mourik A, Engering A, Sanchez-Hernandez M, Klein N, Callard R, van Putten JP, van der Ley P, van Kooyk Y and van de Winkel JG. 2006. ''Neisseria meningitidis'' expressing Lgtb lipopolysaccharide targets DC-SIGN and modulates dendritic cell function. Cell Microbiol. 8:316-325</ref>
*''Helicobacter pylori'' LPS-associated LeX glycan antigens <ref name="Bergman 2004">Bergman MP, Engering A, Smits HH, van Vliet SJ, van Bodegraven AA, Wirth HP, Kapsenberg ML, Vandenbroucke-Grauls CM, van Kooyk Y and Appelmelk BJ. 2004. ''Helicobacter py''lori modulates the T helper cell 1/T helper cell 2 balance through phase-variable interaction between lipopolysaccharide and DC-SIGN. J Exp Med. 200:979-990</ref>
 
=== Cellular expression of GBP and ligands ===

DC-SIGN is expressed on dendritic cells and dendritic cell-like macrophages. Pathogens expressing DC-SIGN ligands include: ''Mycobacterium tuberculosis'', ''Schistosoma mansoni'', ''Candida albicans'', ''Escherichia coli'', ''Neisseria meningitides'', ''Helicobacter pylori'', and others (see above).
 

=== Biosynthesis of ligands ===
Glycans on viruses 
High mannose oligosaccharides on viral envelope proteins that are ligands for DC-SIGN result from incomplete processing of glycans in the pathway for biosynthesis of complex N-linked glycans ([http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/geMolecule.jsp?slideNumber=default GT Database]).
 
Glycans on bacteria 
The biosynthesis pathways for the bacterial lipopolysaccharides have been extensively studied and the gene families responsible for the expression of different glycan sequences have been characterized.<ref name”Raetz2002”>Raetz CR and Whitfield C (2002) Lipopolysaccharide endotoxins. Annu. Rev. Biochem. 71, 635-700</ref>
 
The mycobacterial transferases for synthesis of the lipo-arabinomannan (LAM) core and the extended ManLAM structures have been characterized.<ref name”Tam2009”>Tam, P-H and Lowary, TL (2009) Recent advances in mycobacterial cell wall glycan biosynthesis. Cur. Opin Struct. Biol. 13, 618-625</ref>
 
Glycans on fungi 
Biosynthesis mannans on fungi has been well studied in a number of species. For example, in the yeast S. cerevisiae, the KRE2/MNT1 genes encode mannosyltransferases that synthesize both N- and O-linked mannans.<ref name”Lussier1999”>Lussier, M, Sdicu, A-M and Bussey, H (1999) The KTR and MNN1 mannosyltransferase families of Saccharomyces cerevisiae. Biochim. Biophys. Acta 1426, 323-334</ref>
 
Glycans on parasites 
Some data give insight in the biosynthesis of DC-SIGN ligands in parasitic helminths. In Schistosoma mansoni <ref>DeBose-Boyd R, Nyame AK, Cummings RD. 1996. Schistosoma mansoni: characterization of an α1-3 fucosyltransferase in adult parasites. Exp Parasitol. 82: 1-10</ref><ref>Marques Jr ET Jr, Ichikawa Y, Strand M, August JT, Hart GW, Schnaar RL. 2001. Fucosyltransferases in ''Schistosoma mansoni'' development. Glycobiology 11: 249-59</ref> and ''Haemonchus contortus'' <ref>DeBose-Boyd RA, Nyame AK, Jasmer DP, Cummings RD. 1998. The ruminant parasite ''Haemonchus contortus'' expresses an α1,3-fucosyltransferase capable of synthesizing the Lewis x and sialyl Lewis x antigens. Glycoconjugate J. 15: 789-98</ref> α1,3-fucosyltransferases have been identified, which may be involved in generation of Galβ1-4(Fucα1-3)GlcNAc-R (Lewis X), and/or GalNAcβ1-4(Fucα1-3)GlcNAc-R (LDNF). Combined transcriptome (putative glycosyltransferase genes) and glycome analyses of Schistosoma revealed that female schistosomes synthesize preferably terminal LacNAc and Lewis X, whereas male worms synthesize more LDN/LDNF antigens <ref>Hokke CH, Fitzpatrick JM and Hoffmann KF. 2007. Integrating transcriptome, proteome and glycome analyses of Schistosoma biology. Trends in Parasitology 23: 165-174</ref>.

=== Structure ===
[[image:DC-SIGN_4.jpg]] 
Crystal structures of the CRD of DC-SIGN bound to a mannose-containing oligosaccharide and lacto-N-fucopentaose have been analyzed.<ref name="Feinberg 2001"/><ref name="Guo 2004"/> The first structure can be used to model the binding of the outer portion of a high mannose oligosaccharide and the second structure shows how the Lewisx trisaccharide fits into the binding site. The high mannose oligosaccharide makes extensive interactions in an extended binding site, while the more rigid Lewisx oligosaccharide binds primarily through the fucose residues, with some additional stabilizing interactions with the galactose. The overall structure of the tetrameric extracellular domain has been deduced from crystal structures of the repeats in the neck domain of the related protein DC-SIGNR (L-SIGN)<ref name="Feinberg 2009">Feinberg, H, Tso, CKW, Taylor, ME, Drickamer, K and Weis, WI. 2009. Segmented helical structure of the neck region of the glycan-binding receptor DC-SIGNR. J Mol Biol 394:613-620</ref> and oligomeric C-terminal fragments of DC-SIGN that contain the CRD<ref name="Feinberg 2005">Feinberg, H, Guo, Y, Mitchell, DA, Drickamer, K and Weis, WI. 2005. Extended neck regions stabilze tetramers of the receptors DC-SIGN and DC-SIGNR. J Biol Chem 280:1327-1335</ref>.
 

=== Biological roles of GBP-ligand interaction ===
''Biological roles for DC-SIGN include'':
*DC-SIGN mediates interactions between dendritic cells (DCs) and resting T cells <ref name="Geijtenbeek 2000"/> and between DCs and neutrophils <ref>van Gisbergen KP, Sanchez-Hernandez M, Geijtenbeek TB and van Kooyk Y. 2005. Neutrophils mediate immune modulation of dendritic cells through glycosylation-dependent interactions between MAC-1 and DC-SIGN. J Exp Med. 201:1281-1292</ref>.
*DC-SIGN contributes to adhesion and rolling of DCs on primary human umbilical vein endothelial cells <ref>Geijtenbeek TB, Krooshoop DJ, Bleijs DA, van Vliet SJ, van Duijnhoven GC, Grabovsky V, Alon R, Figdor CG and van Kooyk Y. 2000. DC-SIGN-ICAM-2 interaction mediates dendritic cell trafficking. Nat Immunol. 1:353-357</ref><ref name="Garcia 2008"/>
*interactions of DC-SIGN with Lewis antigens on colorectal tumor cells impair the function and differentiation of dendritic cells <ref name="Nonaka 2008"/>
*DC-SIGN can mediate bacterial adherence and phagocytosis <ref name="Zhang 2006"/>.
*viruses target DC-SIGN to promote infection and spread to cells <ref>Geijtenbeek TB, Kwon DS, Torensma R, van Vliet SJ, van Duijnhoven GC, Middel J, Cornelissen IL, Nottet HS, KewalRamani VN, Littman DR, Figdor CG and van Kooyk Y. 2000. DC-SIGN, a dendritic cell-specific HIV-1-binding protein that enhances trans-infection of T cells. Cell. 100:587-597</ref><ref>Navarro-Sanchez E, Altmeyer R, Amara A, Schwartz O, Fieschi F, Virelizier JL, Arenzana-Seisdedos F and Despres P. 2003. Dendritic-cell-specific ICAM3-grabbing non-integrin is essential for the productive infection of human dendritic cells by mosquito-cell-derived dengue viruses. EMBO Rep. 4:723-728</ref><ref>Simmons G, Reeves JD, Grogan CC, Vandenberghe LH, Baribaud F, Whitbeck JC, Burke E, Buchmeier MJ, Soilleux EJ, Riley JL, Doms RW, Bates P and Pohlmann S. 2003. DC-SIGN and DC-SIGNR bind Ebola glycoproteins and enhance infection of macrophages and endothelial cells. Virology. 305:115-123</ref><ref>Hodges A, Sharrocks K, Edelmann M, Baban D, Moris A, Schwartz O, Drakesmith H, Davies K, Kessler B, McMichael A and Simmons A. 2007. Activation of the lectin DC-SIGN induces an immature dendritic cell phenotype triggering Rho-GTPase activity required for HIV-1 replication. Nat Immunol. 8:569-577</ref>
*activation of DC-SIGN by pathogens can contribute to T helper type 1 (Th)1 cell activity <ref name="Steeghs 2006"/><ref>van Stijn CM, Meyer S, van den Broek M, Bruijns SC, van Kooyk Y, Geyer R and van Die I. 2010. ''Schistosoma mansoni'' worm glycolipids induce an inflammatory phenotype in human dendritic cells by cooperation of TLR4 and DC-SIGN. Mol Immunol. 47:1544-1552</ref>
*some pathogens target DC-SIGN to suppress Th1 cell development <ref name="Bergman 2004"/><ref>Geijtenbeek TB, Van Vliet SJ, Koppel EA, Sanchez-Hernandez M, Vandenbroucke-Grauls CM, Appelmelk B and Van Kooyk Y. 2003. Mycobacteria target DC-SIGN to suppress dendritic cell function. J Exp Med. 197:7-17</ref>
* the murine DC-SIGN homologue SIGNR3 contributes to early host defense against Mycobacterium tuberculosis <ref>Tanne A, Ma B, Boudou F, Tailleux L, Botella H, Badell E, Levillain F, Taylor ME, Drickamer K, Nigou J, Dobos KM, Puzo G, Vestweber D, Wild MK, Marcinko M, Sobieszczuk P, Stewart L, Lebus D, Gicquel B, Neyrolles O. 2009. A murine DC-SIGN homologue contributes to early host defense against ''Mycobacterium tub''erculosis. J Exp Med 206: 2205-2220</ref>
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=DC-SIGN&maxresults=20 CFG database search results for DC-SIGN].

=== Glycan profiling ===
LeX antigens, which are potential ligands for DC-SIGN, have been identified by the Analytical Glycotechnology Core in the following cells of the immune system:
 
 
Human:
[http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=B-Cells&operation=refine&templateKey=2&12=CellType&submit=submit B-cells], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=Basophils&operation=refine&templateKey=2&12=CellType&submit=submit basophils], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=Dendritic+Cells&operation=refine&templateKey=2&12=CellType&submit=submit dendritic cells], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=Eosinophils+&operation=refine&templateKey=2&12=CellType&submit=submit eosinophils], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=Human+Dermal+Lymphatic+Endothelial+Cells+%28HDLEC%29+&operation=refine&templateKey=2&12=CellType&submit=submit human dermal lymphatic endothelial cells], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=Macrophages&operation=refine&templateKey=2&12=CellType&submit=submit macrophages], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=Mast+Cells&operation=refine&templateKey=2&12=CellType&submit=submit mast cells], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=Monocytes&operation=refine&templateKey=2&12=CellType&submit=submit monocytes], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=Natural+Killer+Cells&operation=refine&templateKey=2&12=CellType&submit=submit natural killer cells], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=Neutrophils&operation=refine&templateKey=2&12=CellType&submit=submit neutrophils], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=Peripheral+Blood+Mononuclear+Cells+%28PBMC%29&operation=refine&templateKey=2&12=CellType&submit=submit peripheral blood mononuclear cells], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Human&15=&10=&9=Peripheral+Blood+Mononuclear+Cells+%28PBMC%29&operation=refine&templateKey=2&12=CellType&submit=submit T cells]
 
 
Mouse:
[http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Mouse&15=&10=&9=B1+Cells&operation=refine&templateKey=2&12=CellType&submit=submit B1 cells], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Mouse&15=&10=&9=B1+Cells&operation=refine&templateKey=2&12=CellType&submit=submit B2 cells], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Mouse&15=&10=&9=Cytokine-induced+killer+%28CIK%29+cells&operation=refine&templateKey=2&12=CellType&submit=submit cytokine induced killer cells], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Mouse&15=&10=&9=Eosinophils+&operation=refine&templateKey=2&12=CellType&submit=submit eosinophils], [http://www.functionalglycomics.org/glycomics/common/jsp/samples/searchSample.jsp?5=Mouse&15=&10=&9=Macrophages&operation=refine&templateKey=2&12=CellType&submit=submit macrophages]
 
 
([http://www.functionalglycomics.org/glycomics/publicdata/glycoprofiling-new.jsp all Analytical Glycotechnology Core data])
 
 
T-Cells, which would be the most relevant interacting partner, contain substantial levels of LeX in humans.

=== Glycogene microarray ===
Probes for human DC-SIGN have been included in all versions of the CFG glycogene chip.
 

=== Knockout mouse lines ===

Knockout mice for three potential DC-SIGN orthologues ([https://www.functionalglycomics.org/static/consortium/resources/DataCoreFdc.shtml DC-SIGN], [https://www.functionalglycomics.org/static/consortium/resources/DataCoreFsr1.shtml SIGNR1], and [https://www.functionalglycomics.org/static/consortium/resources/DataCoreFsr3.shtml SIGNR3]) were created by the CFG and distributed to PIs, and their [http://www.functionalglycomics.org/glycomics/publicdata/phenotyping.jsp phenotypes] were analyzed.

=== Glycan array ===

Glycan array analysis <ref name="Guo 2004"/><ref name="Liempt 2006"/>and synthetic oligosaccharides were used to elucidate DC-SIGN [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_GLYCAN_v2_52_06122003 glycan-binding specificity] and analyze the mechanism of specific glycan binding. See all glycan array results for [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=dc-sign&cat=coreh DC-SIGN here]. See glycan array screening results for these related GBPs: [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=langerin&cat=coreh langerin,] [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=DCIR&cat=coreh DCIR,] and [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=DC-SIGNR&cat=coreh DC-SIGNR.]

== Related GBPs ==
Other dendritic cell lectins include langerin [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=langerin&maxresults=20 (CFG data)], DCIR [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=DCIR&maxresults=20 (CFG data)], and DCAR. Paralogs on other cells include DC-SIGNR [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=DC-SIGNR&maxresults=20 (CFG data)].

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Kurt Drickamer, Irma van Die, Yvette van Kooyk

Subtilase cytotoxin (SubAB)

2011-04-14T17:56:42Z

Kurt Drickamer: /* Biosynthesis of ligands */

'''AB5 toxins''' are an important family of bacterial toxins, so termed because they comprise a catalytic A subunit, non-covalently linked to a pentameric B subunit that binds to specific host cell surface glycans. There are three well-characterised AB5 toxin sub-families: (i) cholera toxin (Ctx) and the closely related E. coli heat labile enterotoxins (LT-I and LT-II); (ii) pertussis toxin (Ptx); and (iii) Shiga toxin (Stx). In each case, these AB5 toxins are key virulence factors of the bacteria that produce them: Vibrio cholerae and enterotoxigenic E. coli [ETEC] (Ctx and LT-I&II, respectively); Bordetella pertussis (Ptx); Shiga toxigenic E. coli [STEC] and Shigella dysenteriae (Stx). A fourth sub-family, subtilise cytotoxin (SubAB), also produced by STEC, has been described relatively recently. The AB5 toxins from each sub-family possess unique properties that arise from differing catalytic activities of the A subunit and/or differing receptor specificities of the B subunit. The A subunits of the Ctx/LT and Ptx families ADP-ribosylate the Gsα and Giα proteins, respectively, disrupting signal transduction pathways. This results in an increase in intracellular cAMP levels and disregulation of ion transport mechanisms. Stx family A subunits have RNA N-glycosidase activity, and inhibit eukaryotic protein synthesis by cleaving a specific adenine base from 28S rRNA, while SubA is a highly specific subtilase-like serine protease that cleaves the essential endoplasmic reticulum chaperone BiP/GRP78. Binding of AB5 toxin B subunits to cognate host glycan receptors triggers internalization by receptor- mediated endocytosis, followed by trafficking to the appropriate intracellular compartment. The glycan receptors for AB5 toxin B subunit pentamers are displayed either on glycolipids (for Ctx/LT and Stx) or on glycoproteins (for Ptx and SubAB). Glycan receptor specificity is critical for the pathogenic process, as it determines host susceptibility, tissue tropism, and the nature and spectrum of the resultant pathology. Knowledge of the molecular/structural basis for B subunit pentamer/glycan interactions is providing a rational framework for design of specific toxin inhibitors with considerable potential as anti-infective therapeutic agents<ref name="Fan 1">Fan, E. et al. (2000). AB5 toxins: structures and inhibitor design. Curr. Opin. Struct. Biol. 10: 680-686.</ref>.

'''SubAB''' is a recently-discovered prototype of a new AB5 toxin sub-family, with a highly novel mode of inducing cytotoxicity<ref>Paton, A.W., Srimanote, P., Talbot, U.M., Wang, H., and Paton, J.C. (2004). A new family of potent AB5 cytotoxins produced by Shiga toxigenic Escherichia coli. J. Exp. Med. 200: 35-46.</ref><ref>Paton, A.W., Beddoe, T., Thorpe, C.M., Whisstock, J.C., Wilce, M.C.J., Rossjohn, J., Talbot, U.M. and Paton J.C. (2006). AB5 subtilase cytotoxin inactivates the endoplasmic reticulum chaperone BiP. Nature 443: 548-552.</ref>. It has been selected as a paradigm because the other AB5 toxin sub-families referred to above have been known for many years, and a substantial body of information on toxin-receptor interactions had been built up using conventional biochemical techniques<ref name="Fan 1"/><ref>Merrit, E. A. and Hol, W. G. J. (1995). AB5 toxins. Curr. Opin. Struct. Biol. 5: 165-171.</ref>. SubB has recently been shown to bind to N-linked glycans displayed on several glycoproteins on the surface of Vero and HeLa cells, including α2β1integrin<ref name="Yahiro 2006">Yahiro, K., Morinaga, N., Satoh, M., Matsuura, G., Tomonaga, T., Nomura, F., Moss, J., Noda, M. (2006). Identification and characterization of receptors for vacuolating activity of subtilase cytotoxin. Mol. Microbiol. 62: 480–490.</ref>. However, nothing was known about the identity of the cognate glycan structures prior to accessing the CFG Core H glycan array facilities. Thus, the CFG has enabled seminal studies on SubB-host receptor interactions. Glycan array analysis showed that SubB has a high degree of specificity for glycans terminating with α2-3-linked N-glycolylneuraminic acid (Neu5Gc), with little discrimination for the penultimate moiety<ref name="Byres 6">Byres, E., Paton, A.W., Paton, J.C., Löfling, J.C., Smith, D.F., Wilce, M.C.J., Talbot, U.M., Chong, D.C., Yu, H., Huang, S., Chen, X., Varki, N.M., Varki, A., Rossjohn, J., and Beddoe, T. (2008). Incorporation of a non-human glycan mediates human susceptibility to a bacterial toxin. Nature. 456: 648-652.</ref>. Roughly 20-fold weaker binding was seen with otherwise identical glycans that terminated in α2-3-linked N-acetylneuraminic acid (Neu5Ac), which differs by one hydroxyl group from Neu5Gc. Binding was reduced over 30-fold if the Neu5Gc linkage was changed from α2-3 to α2-6, and 100-fold if the terminal sialic acid was removed. This high specificity for Neu5Gc-terminating glycans is believed to be unique amongst bacterial toxins<ref name="Byres 6"/>. Identification of the SubB receptor glycan informed structural analysis of SubB in complex with synthetic oligosaccharides provided by another CFG PI. This showed that Neu5Gc bound to a shallow pocket halfway down the sides of the SubB pentamer, whereas identical experiments using Neu5Ac failed to show any binding<ref name="Byres 6"/>. In contrast, CtxB whose receptor is a ganglioside rather than a glycoprotein, has a deep receptor binding pocket located on the base of the pentamer, juxtaposed to the membrane<ref name="Merritt 1997">Merritt, E.A.; Sarfarty, S.; Jobling, M.G.; Chang, T.; Holmes, R.K.; Hirst, T.R.; Hol, W.G.
Structural studies of receptor binding by cholera toxin mutants. Protein Sci. 1997, 6, 1516–1528.</ref>. In the SubB-Neu5Gc complex, Neu5Gc makes key interactions with the side chains of Asp8, Ser12, Glu36 and Tyr78<ref name="Byres 6"/>. Neu5Gc differs from Neu5Ac by the addition of a hydroxyl on the methyl group of the N-Acetyl moiety, which makes additional crucial interactions with SubB; namely the extra hydroxyl points towards and interacts with Tyr78OH and also hydrogen bonds with the main chain of Met10. These key interactions could not occur with Neu5Ac, thus explaining the marked preference for Neu5Gc6. The biological relevance of the structural analysis has been confirmed by further interacting residues<ref name="Byres 6"/>.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
CFG Participating Investigators (PIs) have made seminal contributions to understanding the biology of this highly potent toxin, in particular the molecular interactions between the binding subunit SubB and cognate host cell glycans described above. These include Xi Chen, Adrienne Paton, James Paton, David Smith, and Ajit Varki. Importantly, on-going collaborations have been established between these PIs as a consequence of involvement in the CFG, and these have already generated one collaborative paper in ''Nature''<ref name="Byres 6"/>.

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about SubAB, its carbohydrate ligand(s), and how they interact to mediate cell communication.
=== Carbohydrate ligands ===
SubB binds N-linked glycans displayed on glycoproteins on the surface of Vero and HeLa cells, including α2β1integrin<ref name="Yahiro 2006"/>. Screening with the CFG glycan array showed that SubB has a high degree of specificity for glycans terminating with α2-3-linked N-glycolylneuraminic acid (Neu5Gc), with little discrimination for the penultimate moiety<ref name="Byres 6"/>. Roughly 20-fold weaker binding was seen with otherwise identical glycans that terminated in α2-3-linked N-acetylneuraminic acid (Neu5Ac), which differs by one hydroxyl group from Neu5Gc. Binding was reduced over 30-fold if the Neu5Gc linkage was changed from α2-3 to α2-6, and 100-fold if the terminal sialic acid was removed. This high specificity for Neu5Gc-terminating glycans is believed to be unique amongst bacterial toxins<ref name="Byres 6"/>.
 
=== Cellular expression of GBP and ligands ===
Subtilase cytotoxin, SubAB, is produced by Shiga toxigenic E. coli. Other members of the AB5 toxin family are expressed as follows: Cholera toxin (Ctx) is produced by Vibrio cholerae, the heat-labile enterotoxins LT-I and LT-II are produced by enterotoxigenic E. coli (ETEC), pertussis toxin (Ptx) is produced by Bordetella pertussis, and shiga toxin (Stx) is produced by Shiga toxigenic E. coli (STEC) and Shigella dysenteriae.
 
AB5 toxin family members bind to glycan receptors in the host. The glycan receptors for AB5 toxin B subunit pentamers are displayed either on glycolipids (for Ctx/LT and Stx) or on glycoproteins (for Ptx and SubAB). 
=== Biosynthesis of ligands ===
Synthesis of CMP-NeuGc from CMP-NeuAc is mediated by cytidine monophospho-N-acetylneuraminic acid hydroxylase, encoded by the Cmah gene, which is functional in mice but not in humans<ref name”Irie1998”>Irie, A, Koyama, S, Kozutsumi, Y, Kawasaki, T and Suzuki, A (1998) The Molecular Basis for the Absence of N-Glycolylneuraminic Acid in Humans. J Biol Chem 273, 15866-15871</ref>. Transfer of the NeuGc to glycan acceptors is mediated by multiple 2,3-sialyltransferases ([http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/gtdb.jsp?species=Mus+musculus&classification=SialylT&linkage_attaching=%3F&linkage_anomeric=a&linkage_position=3&linkage_base=%3F&pgname=&from=multiple&title=Multiple+Criteria+Search+Results&slideNumber=multipleQuery Database]), which work with either N-acetyl- or N-glycolylneuraminic acid donors<ref name”Higa1986”>Higa, HH and Paulson, JC (1986) Sialylation of glycoprotein oligosaccharides with N-Acetyl-, N-Glycolyl-, and N-O-Diacetylneuraminic Acids. J Biol Chem 260, 8836-8849</ref>.
 

=== Structure ===
Structural analysis of SubB in complex with synthetic oligosaccharides showed that Neu5Gc binds to a shallow pocket halfway down the sides of the SubB pentamer, whereas identical experiments using Neu5Ac failed to show any binding<ref name="Byres 6"/>. In contrast, CtxB, whose receptor is a ganglioside rather than a glycoprotein, has a deep receptor binding pocket located on the base of the pentamer, juxtaposed to the membrane<ref name="Merritt 1997"/>. In the SubB-Neu5Gc complex, Neu5Gc makes key interactions with the side chains of Asp8, Ser12, Glu36 and Tyr78<ref name="Byres 6"/>. Neu5Gc differs from Neu5Ac by the addition of a hydroxyl on the methyl group of the N-Acetyl moiety, which makes additional crucial interactions with SubB; namely, the extra hydroxyl points towards and interacts with Tyr78OH and also hydrogen bonds with the main chain of Met10. These key interactions could not occur with Neu5Ac, thus explaining the marked preference for Neu5Gc6.
 
=== Biological roles of GBP-ligand interaction ===
Glycan receptor specificity is critical for the pathogenic process, as it determines host susceptibility, tissue tropism, and the nature and spectrum of the resultant pathology.
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the CFG database search results for [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=SubAB&maxresults=20 SubAB] and [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=subtilase&maxresults=20 subtilase].

=== Glycan profiling ===

 
=== Glycogene microarray ===
SubAB is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
Not applicable.
 

=== Glycan array ===
The CFG glycan array was fundamental in the identification and characterization of [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_759 SubB receptor specificity]. This information then permitted structural analysis of protein-glycan complexes. Glycan array analysis was also critical for investigating the influence of mutation of SubB residues predicted to be critical for Neu5Gc-specific binding on the repertoire of glycan structures engaged by the toxin. To see all glycan array results for subtilase cytotoxin, click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=subtilase%20AND%20cytotoxin&cat=coreh here].

== Related GBPs ==

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Joseph Barbieri, James Paton

Subtilase cytotoxin (SubAB)

2011-04-14T17:55:58Z

Kurt Drickamer: /* Biosynthesis of ligands */

'''AB5 toxins''' are an important family of bacterial toxins, so termed because they comprise a catalytic A subunit, non-covalently linked to a pentameric B subunit that binds to specific host cell surface glycans. There are three well-characterised AB5 toxin sub-families: (i) cholera toxin (Ctx) and the closely related E. coli heat labile enterotoxins (LT-I and LT-II); (ii) pertussis toxin (Ptx); and (iii) Shiga toxin (Stx). In each case, these AB5 toxins are key virulence factors of the bacteria that produce them: Vibrio cholerae and enterotoxigenic E. coli [ETEC] (Ctx and LT-I&II, respectively); Bordetella pertussis (Ptx); Shiga toxigenic E. coli [STEC] and Shigella dysenteriae (Stx). A fourth sub-family, subtilise cytotoxin (SubAB), also produced by STEC, has been described relatively recently. The AB5 toxins from each sub-family possess unique properties that arise from differing catalytic activities of the A subunit and/or differing receptor specificities of the B subunit. The A subunits of the Ctx/LT and Ptx families ADP-ribosylate the Gsα and Giα proteins, respectively, disrupting signal transduction pathways. This results in an increase in intracellular cAMP levels and disregulation of ion transport mechanisms. Stx family A subunits have RNA N-glycosidase activity, and inhibit eukaryotic protein synthesis by cleaving a specific adenine base from 28S rRNA, while SubA is a highly specific subtilase-like serine protease that cleaves the essential endoplasmic reticulum chaperone BiP/GRP78. Binding of AB5 toxin B subunits to cognate host glycan receptors triggers internalization by receptor- mediated endocytosis, followed by trafficking to the appropriate intracellular compartment. The glycan receptors for AB5 toxin B subunit pentamers are displayed either on glycolipids (for Ctx/LT and Stx) or on glycoproteins (for Ptx and SubAB). Glycan receptor specificity is critical for the pathogenic process, as it determines host susceptibility, tissue tropism, and the nature and spectrum of the resultant pathology. Knowledge of the molecular/structural basis for B subunit pentamer/glycan interactions is providing a rational framework for design of specific toxin inhibitors with considerable potential as anti-infective therapeutic agents<ref name="Fan 1">Fan, E. et al. (2000). AB5 toxins: structures and inhibitor design. Curr. Opin. Struct. Biol. 10: 680-686.</ref>.

'''SubAB''' is a recently-discovered prototype of a new AB5 toxin sub-family, with a highly novel mode of inducing cytotoxicity<ref>Paton, A.W., Srimanote, P., Talbot, U.M., Wang, H., and Paton, J.C. (2004). A new family of potent AB5 cytotoxins produced by Shiga toxigenic Escherichia coli. J. Exp. Med. 200: 35-46.</ref><ref>Paton, A.W., Beddoe, T., Thorpe, C.M., Whisstock, J.C., Wilce, M.C.J., Rossjohn, J., Talbot, U.M. and Paton J.C. (2006). AB5 subtilase cytotoxin inactivates the endoplasmic reticulum chaperone BiP. Nature 443: 548-552.</ref>. It has been selected as a paradigm because the other AB5 toxin sub-families referred to above have been known for many years, and a substantial body of information on toxin-receptor interactions had been built up using conventional biochemical techniques<ref name="Fan 1"/><ref>Merrit, E. A. and Hol, W. G. J. (1995). AB5 toxins. Curr. Opin. Struct. Biol. 5: 165-171.</ref>. SubB has recently been shown to bind to N-linked glycans displayed on several glycoproteins on the surface of Vero and HeLa cells, including α2β1integrin<ref name="Yahiro 2006">Yahiro, K., Morinaga, N., Satoh, M., Matsuura, G., Tomonaga, T., Nomura, F., Moss, J., Noda, M. (2006). Identification and characterization of receptors for vacuolating activity of subtilase cytotoxin. Mol. Microbiol. 62: 480–490.</ref>. However, nothing was known about the identity of the cognate glycan structures prior to accessing the CFG Core H glycan array facilities. Thus, the CFG has enabled seminal studies on SubB-host receptor interactions. Glycan array analysis showed that SubB has a high degree of specificity for glycans terminating with α2-3-linked N-glycolylneuraminic acid (Neu5Gc), with little discrimination for the penultimate moiety<ref name="Byres 6">Byres, E., Paton, A.W., Paton, J.C., Löfling, J.C., Smith, D.F., Wilce, M.C.J., Talbot, U.M., Chong, D.C., Yu, H., Huang, S., Chen, X., Varki, N.M., Varki, A., Rossjohn, J., and Beddoe, T. (2008). Incorporation of a non-human glycan mediates human susceptibility to a bacterial toxin. Nature. 456: 648-652.</ref>. Roughly 20-fold weaker binding was seen with otherwise identical glycans that terminated in α2-3-linked N-acetylneuraminic acid (Neu5Ac), which differs by one hydroxyl group from Neu5Gc. Binding was reduced over 30-fold if the Neu5Gc linkage was changed from α2-3 to α2-6, and 100-fold if the terminal sialic acid was removed. This high specificity for Neu5Gc-terminating glycans is believed to be unique amongst bacterial toxins<ref name="Byres 6"/>. Identification of the SubB receptor glycan informed structural analysis of SubB in complex with synthetic oligosaccharides provided by another CFG PI. This showed that Neu5Gc bound to a shallow pocket halfway down the sides of the SubB pentamer, whereas identical experiments using Neu5Ac failed to show any binding<ref name="Byres 6"/>. In contrast, CtxB whose receptor is a ganglioside rather than a glycoprotein, has a deep receptor binding pocket located on the base of the pentamer, juxtaposed to the membrane<ref name="Merritt 1997">Merritt, E.A.; Sarfarty, S.; Jobling, M.G.; Chang, T.; Holmes, R.K.; Hirst, T.R.; Hol, W.G.
Structural studies of receptor binding by cholera toxin mutants. Protein Sci. 1997, 6, 1516–1528.</ref>. In the SubB-Neu5Gc complex, Neu5Gc makes key interactions with the side chains of Asp8, Ser12, Glu36 and Tyr78<ref name="Byres 6"/>. Neu5Gc differs from Neu5Ac by the addition of a hydroxyl on the methyl group of the N-Acetyl moiety, which makes additional crucial interactions with SubB; namely the extra hydroxyl points towards and interacts with Tyr78OH and also hydrogen bonds with the main chain of Met10. These key interactions could not occur with Neu5Ac, thus explaining the marked preference for Neu5Gc6. The biological relevance of the structural analysis has been confirmed by further interacting residues<ref name="Byres 6"/>.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
CFG Participating Investigators (PIs) have made seminal contributions to understanding the biology of this highly potent toxin, in particular the molecular interactions between the binding subunit SubB and cognate host cell glycans described above. These include Xi Chen, Adrienne Paton, James Paton, David Smith, and Ajit Varki. Importantly, on-going collaborations have been established between these PIs as a consequence of involvement in the CFG, and these have already generated one collaborative paper in ''Nature''<ref name="Byres 6"/>.

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about SubAB, its carbohydrate ligand(s), and how they interact to mediate cell communication.
=== Carbohydrate ligands ===
SubB binds N-linked glycans displayed on glycoproteins on the surface of Vero and HeLa cells, including α2β1integrin<ref name="Yahiro 2006"/>. Screening with the CFG glycan array showed that SubB has a high degree of specificity for glycans terminating with α2-3-linked N-glycolylneuraminic acid (Neu5Gc), with little discrimination for the penultimate moiety<ref name="Byres 6"/>. Roughly 20-fold weaker binding was seen with otherwise identical glycans that terminated in α2-3-linked N-acetylneuraminic acid (Neu5Ac), which differs by one hydroxyl group from Neu5Gc. Binding was reduced over 30-fold if the Neu5Gc linkage was changed from α2-3 to α2-6, and 100-fold if the terminal sialic acid was removed. This high specificity for Neu5Gc-terminating glycans is believed to be unique amongst bacterial toxins<ref name="Byres 6"/>.
 
=== Cellular expression of GBP and ligands ===
Subtilase cytotoxin, SubAB, is produced by Shiga toxigenic E. coli. Other members of the AB5 toxin family are expressed as follows: Cholera toxin (Ctx) is produced by Vibrio cholerae, the heat-labile enterotoxins LT-I and LT-II are produced by enterotoxigenic E. coli (ETEC), pertussis toxin (Ptx) is produced by Bordetella pertussis, and shiga toxin (Stx) is produced by Shiga toxigenic E. coli (STEC) and Shigella dysenteriae.
 
AB5 toxin family members bind to glycan receptors in the host. The glycan receptors for AB5 toxin B subunit pentamers are displayed either on glycolipids (for Ctx/LT and Stx) or on glycoproteins (for Ptx and SubAB). 
=== Biosynthesis of ligands ===
Synthesis of CMP-NeuGc from CMP-NeuAc is mediated by cytidine monophospho-N-acetylneuraminic acid hydroxylase, encoded by the Cmah gene, which is functional in mice but not in humans<ref name”Irie1998”>Irie, A, Koyama, S, Kozutsumi, Y, Kawasaki, T and Suzuki, A (1998) The Molecular Basis for the Absence of N-Glycolylneuraminic Acid in Humans. J Biol Chem 273, 15866-15871</ref>. Transfers of the NeuGc to glycan acceptors is mediated by multiple 2,3-sialyltransferases ([http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/gtdb.jsp?species=Mus+musculus&classification=SialylT&linkage_attaching=%3F&linkage_anomeric=a&linkage_position=3&linkage_base=%3F&pgname=&from=multiple&title=Multiple+Criteria+Search+Results&slideNumber=multipleQuery Database]), which work with either N-acetyl- or N-glycolylneuraminic acid donors<ref name”Higa1986”>Higa, HH and Paulson, JC (1986) Sialylation of glycoprotein oligosaccharides with N-Acetyl-, N-Glycolyl-, and N-O-Diacetylneuraminic Acids. J Biol Chem 260, 8836-8849</ref>.
 

=== Structure ===
Structural analysis of SubB in complex with synthetic oligosaccharides showed that Neu5Gc binds to a shallow pocket halfway down the sides of the SubB pentamer, whereas identical experiments using Neu5Ac failed to show any binding<ref name="Byres 6"/>. In contrast, CtxB, whose receptor is a ganglioside rather than a glycoprotein, has a deep receptor binding pocket located on the base of the pentamer, juxtaposed to the membrane<ref name="Merritt 1997"/>. In the SubB-Neu5Gc complex, Neu5Gc makes key interactions with the side chains of Asp8, Ser12, Glu36 and Tyr78<ref name="Byres 6"/>. Neu5Gc differs from Neu5Ac by the addition of a hydroxyl on the methyl group of the N-Acetyl moiety, which makes additional crucial interactions with SubB; namely, the extra hydroxyl points towards and interacts with Tyr78OH and also hydrogen bonds with the main chain of Met10. These key interactions could not occur with Neu5Ac, thus explaining the marked preference for Neu5Gc6.
 
=== Biological roles of GBP-ligand interaction ===
Glycan receptor specificity is critical for the pathogenic process, as it determines host susceptibility, tissue tropism, and the nature and spectrum of the resultant pathology.
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the CFG database search results for [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=SubAB&maxresults=20 SubAB] and [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=subtilase&maxresults=20 subtilase].

=== Glycan profiling ===

 
=== Glycogene microarray ===
SubAB is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
Not applicable.
 

=== Glycan array ===
The CFG glycan array was fundamental in the identification and characterization of [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_759 SubB receptor specificity]. This information then permitted structural analysis of protein-glycan complexes. Glycan array analysis was also critical for investigating the influence of mutation of SubB residues predicted to be critical for Neu5Gc-specific binding on the repertoire of glycan structures engaged by the toxin. To see all glycan array results for subtilase cytotoxin, click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=subtilase%20AND%20cytotoxin&cat=coreh here].

== Related GBPs ==

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Joseph Barbieri, James Paton

Subtilase cytotoxin (SubAB)

2011-04-14T17:55:15Z

Kurt Drickamer: /* Biosynthesis of ligands */

'''AB5 toxins''' are an important family of bacterial toxins, so termed because they comprise a catalytic A subunit, non-covalently linked to a pentameric B subunit that binds to specific host cell surface glycans. There are three well-characterised AB5 toxin sub-families: (i) cholera toxin (Ctx) and the closely related E. coli heat labile enterotoxins (LT-I and LT-II); (ii) pertussis toxin (Ptx); and (iii) Shiga toxin (Stx). In each case, these AB5 toxins are key virulence factors of the bacteria that produce them: Vibrio cholerae and enterotoxigenic E. coli [ETEC] (Ctx and LT-I&II, respectively); Bordetella pertussis (Ptx); Shiga toxigenic E. coli [STEC] and Shigella dysenteriae (Stx). A fourth sub-family, subtilise cytotoxin (SubAB), also produced by STEC, has been described relatively recently. The AB5 toxins from each sub-family possess unique properties that arise from differing catalytic activities of the A subunit and/or differing receptor specificities of the B subunit. The A subunits of the Ctx/LT and Ptx families ADP-ribosylate the Gsα and Giα proteins, respectively, disrupting signal transduction pathways. This results in an increase in intracellular cAMP levels and disregulation of ion transport mechanisms. Stx family A subunits have RNA N-glycosidase activity, and inhibit eukaryotic protein synthesis by cleaving a specific adenine base from 28S rRNA, while SubA is a highly specific subtilase-like serine protease that cleaves the essential endoplasmic reticulum chaperone BiP/GRP78. Binding of AB5 toxin B subunits to cognate host glycan receptors triggers internalization by receptor- mediated endocytosis, followed by trafficking to the appropriate intracellular compartment. The glycan receptors for AB5 toxin B subunit pentamers are displayed either on glycolipids (for Ctx/LT and Stx) or on glycoproteins (for Ptx and SubAB). Glycan receptor specificity is critical for the pathogenic process, as it determines host susceptibility, tissue tropism, and the nature and spectrum of the resultant pathology. Knowledge of the molecular/structural basis for B subunit pentamer/glycan interactions is providing a rational framework for design of specific toxin inhibitors with considerable potential as anti-infective therapeutic agents<ref name="Fan 1">Fan, E. et al. (2000). AB5 toxins: structures and inhibitor design. Curr. Opin. Struct. Biol. 10: 680-686.</ref>.

'''SubAB''' is a recently-discovered prototype of a new AB5 toxin sub-family, with a highly novel mode of inducing cytotoxicity<ref>Paton, A.W., Srimanote, P., Talbot, U.M., Wang, H., and Paton, J.C. (2004). A new family of potent AB5 cytotoxins produced by Shiga toxigenic Escherichia coli. J. Exp. Med. 200: 35-46.</ref><ref>Paton, A.W., Beddoe, T., Thorpe, C.M., Whisstock, J.C., Wilce, M.C.J., Rossjohn, J., Talbot, U.M. and Paton J.C. (2006). AB5 subtilase cytotoxin inactivates the endoplasmic reticulum chaperone BiP. Nature 443: 548-552.</ref>. It has been selected as a paradigm because the other AB5 toxin sub-families referred to above have been known for many years, and a substantial body of information on toxin-receptor interactions had been built up using conventional biochemical techniques<ref name="Fan 1"/><ref>Merrit, E. A. and Hol, W. G. J. (1995). AB5 toxins. Curr. Opin. Struct. Biol. 5: 165-171.</ref>. SubB has recently been shown to bind to N-linked glycans displayed on several glycoproteins on the surface of Vero and HeLa cells, including α2β1integrin<ref name="Yahiro 2006">Yahiro, K., Morinaga, N., Satoh, M., Matsuura, G., Tomonaga, T., Nomura, F., Moss, J., Noda, M. (2006). Identification and characterization of receptors for vacuolating activity of subtilase cytotoxin. Mol. Microbiol. 62: 480–490.</ref>. However, nothing was known about the identity of the cognate glycan structures prior to accessing the CFG Core H glycan array facilities. Thus, the CFG has enabled seminal studies on SubB-host receptor interactions. Glycan array analysis showed that SubB has a high degree of specificity for glycans terminating with α2-3-linked N-glycolylneuraminic acid (Neu5Gc), with little discrimination for the penultimate moiety<ref name="Byres 6">Byres, E., Paton, A.W., Paton, J.C., Löfling, J.C., Smith, D.F., Wilce, M.C.J., Talbot, U.M., Chong, D.C., Yu, H., Huang, S., Chen, X., Varki, N.M., Varki, A., Rossjohn, J., and Beddoe, T. (2008). Incorporation of a non-human glycan mediates human susceptibility to a bacterial toxin. Nature. 456: 648-652.</ref>. Roughly 20-fold weaker binding was seen with otherwise identical glycans that terminated in α2-3-linked N-acetylneuraminic acid (Neu5Ac), which differs by one hydroxyl group from Neu5Gc. Binding was reduced over 30-fold if the Neu5Gc linkage was changed from α2-3 to α2-6, and 100-fold if the terminal sialic acid was removed. This high specificity for Neu5Gc-terminating glycans is believed to be unique amongst bacterial toxins<ref name="Byres 6"/>. Identification of the SubB receptor glycan informed structural analysis of SubB in complex with synthetic oligosaccharides provided by another CFG PI. This showed that Neu5Gc bound to a shallow pocket halfway down the sides of the SubB pentamer, whereas identical experiments using Neu5Ac failed to show any binding<ref name="Byres 6"/>. In contrast, CtxB whose receptor is a ganglioside rather than a glycoprotein, has a deep receptor binding pocket located on the base of the pentamer, juxtaposed to the membrane<ref name="Merritt 1997">Merritt, E.A.; Sarfarty, S.; Jobling, M.G.; Chang, T.; Holmes, R.K.; Hirst, T.R.; Hol, W.G.
Structural studies of receptor binding by cholera toxin mutants. Protein Sci. 1997, 6, 1516–1528.</ref>. In the SubB-Neu5Gc complex, Neu5Gc makes key interactions with the side chains of Asp8, Ser12, Glu36 and Tyr78<ref name="Byres 6"/>. Neu5Gc differs from Neu5Ac by the addition of a hydroxyl on the methyl group of the N-Acetyl moiety, which makes additional crucial interactions with SubB; namely the extra hydroxyl points towards and interacts with Tyr78OH and also hydrogen bonds with the main chain of Met10. These key interactions could not occur with Neu5Ac, thus explaining the marked preference for Neu5Gc6. The biological relevance of the structural analysis has been confirmed by further interacting residues<ref name="Byres 6"/>.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
CFG Participating Investigators (PIs) have made seminal contributions to understanding the biology of this highly potent toxin, in particular the molecular interactions between the binding subunit SubB and cognate host cell glycans described above. These include Xi Chen, Adrienne Paton, James Paton, David Smith, and Ajit Varki. Importantly, on-going collaborations have been established between these PIs as a consequence of involvement in the CFG, and these have already generated one collaborative paper in ''Nature''<ref name="Byres 6"/>.

== Progress toward understanding this GBP paradigm ==
This section documents what is currently known about SubAB, its carbohydrate ligand(s), and how they interact to mediate cell communication.
=== Carbohydrate ligands ===
SubB binds N-linked glycans displayed on glycoproteins on the surface of Vero and HeLa cells, including α2β1integrin<ref name="Yahiro 2006"/>. Screening with the CFG glycan array showed that SubB has a high degree of specificity for glycans terminating with α2-3-linked N-glycolylneuraminic acid (Neu5Gc), with little discrimination for the penultimate moiety<ref name="Byres 6"/>. Roughly 20-fold weaker binding was seen with otherwise identical glycans that terminated in α2-3-linked N-acetylneuraminic acid (Neu5Ac), which differs by one hydroxyl group from Neu5Gc. Binding was reduced over 30-fold if the Neu5Gc linkage was changed from α2-3 to α2-6, and 100-fold if the terminal sialic acid was removed. This high specificity for Neu5Gc-terminating glycans is believed to be unique amongst bacterial toxins<ref name="Byres 6"/>.
 
=== Cellular expression of GBP and ligands ===
Subtilase cytotoxin, SubAB, is produced by Shiga toxigenic E. coli. Other members of the AB5 toxin family are expressed as follows: Cholera toxin (Ctx) is produced by Vibrio cholerae, the heat-labile enterotoxins LT-I and LT-II are produced by enterotoxigenic E. coli (ETEC), pertussis toxin (Ptx) is produced by Bordetella pertussis, and shiga toxin (Stx) is produced by Shiga toxigenic E. coli (STEC) and Shigella dysenteriae.
 
AB5 toxin family members bind to glycan receptors in the host. The glycan receptors for AB5 toxin B subunit pentamers are displayed either on glycolipids (for Ctx/LT and Stx) or on glycoproteins (for Ptx and SubAB). 
=== Biosynthesis of ligands ===
Synthesis of CMP-NeuGc from CMP-NeuAc is mediated by cytidine monophospho-N-acetylneuraminic acid hydroxylase, encoded by the Cmah gene, which is functional in mice but not in humans<ref name”Irie1998”>Irie, A, Koyama, S, Kozutsumi, Y, Kawasaki, T and Suzuki, A (1998) The Molecular Basis for the Absence of N-Glycolylneuraminic Acid in Humans. J Biol Chem 273, 15866-15871</ref>. Transfers of the NeuGc to glycan acceptors is mediated by multiple 2,3-sialyltransferases ([http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/gtdb.jsp?species=Mus+musculus&classification=SialylT&linkage_attaching=%3F&linkage_anomeric=a&linkage_position=3&linkage_base=%3F&pgname=&from=multiple&title=Multiple+Criteria+Search+Results&slideNumber=multipleQuery Database]), which work with either N-acetyl- or N-glycolylneuraminic acid donors<ref name”Higa1986”>Higa, HH and Paulson, JC (1986) Sialylation of glycoprotein oligosaccharides with N-Acetyl-, N-Glycolyl-, and N-O-Diacetylneuraminic Acids. J Biol Chem 260, 8836-8849,/ref>.
 

=== Structure ===
Structural analysis of SubB in complex with synthetic oligosaccharides showed that Neu5Gc binds to a shallow pocket halfway down the sides of the SubB pentamer, whereas identical experiments using Neu5Ac failed to show any binding<ref name="Byres 6"/>. In contrast, CtxB, whose receptor is a ganglioside rather than a glycoprotein, has a deep receptor binding pocket located on the base of the pentamer, juxtaposed to the membrane<ref name="Merritt 1997"/>. In the SubB-Neu5Gc complex, Neu5Gc makes key interactions with the side chains of Asp8, Ser12, Glu36 and Tyr78<ref name="Byres 6"/>. Neu5Gc differs from Neu5Ac by the addition of a hydroxyl on the methyl group of the N-Acetyl moiety, which makes additional crucial interactions with SubB; namely, the extra hydroxyl points towards and interacts with Tyr78OH and also hydrogen bonds with the main chain of Met10. These key interactions could not occur with Neu5Ac, thus explaining the marked preference for Neu5Gc6.
 
=== Biological roles of GBP-ligand interaction ===
Glycan receptor specificity is critical for the pathogenic process, as it determines host susceptibility, tissue tropism, and the nature and spectrum of the resultant pathology.
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the CFG database search results for [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=SubAB&maxresults=20 SubAB] and [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=subtilase&maxresults=20 subtilase].

=== Glycan profiling ===

 
=== Glycogene microarray ===
SubAB is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
Not applicable.
 

=== Glycan array ===
The CFG glycan array was fundamental in the identification and characterization of [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_759 SubB receptor specificity]. This information then permitted structural analysis of protein-glycan complexes. Glycan array analysis was also critical for investigating the influence of mutation of SubB residues predicted to be critical for Neu5Gc-specific binding on the repertoire of glycan structures engaged by the toxin. To see all glycan array results for subtilase cytotoxin, click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=subtilase%20AND%20cytotoxin&cat=coreh here].

== Related GBPs ==

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Joseph Barbieri, James Paton

Reovirus hemagglutinin (sigma 1)

2011-04-11T08:45:55Z

Kurt Drickamer: /* Biosynthesis of ligands */

'''Mammalian orthoreoviruses (reoviruses)''' are useful models for studies of viral receptor recognition and the pathogenesis of viral disease. Reovirus also efficiently lyses tumor cells in experimental animals<ref>Duncan, M.R., Stanish, S.M., and Cox, D.C. Differential sensitivity of normal and transformed human cells to reovirus infection. J. Virol. 28:444-449, 1978.</ref><ref> Coffey, M.C., Strong, J.E., Forsyth, P.A., and Lee, P.W. Reovirus therapy of tumors with activated Ras pathway. Science 282:1332-1334, 1998.</ref> and has shown efficacy in clinical trials for aggressive and refractory human tumors<ref>Stoeckel, J., and Hay, J.G. Drug evaluation: Reolysin--wild-type reovirus as a cancer therapeutic. Curr. Opin. Mol. Ther. 8:249-260, 2006.</ref><ref>Twigger, K., Vidal, L., White, C.L., De Bono, J.S., Bhide, S., Coffey, M., Thompson, B., Vile, R.G., Heinemann, L., Pandha, H.S., et al. Enhanced in vitro and in vivo cytotoxicity of combined reovirus and radiotherapy. Clin. Cancer Res. 14:912-923, 2008. </ref>. Reovirus forms double-shelled particles<ref>Dryden, K.A., Wang, G., Yeager, M., Nibert, M.L., Coombs, K.M., Furlong, D.B., Fields, B.N., and Baker, T.S. Early steps in reovirus infection are associated with dramatic changes in supramolecular structure and protein conformation: analysis of virions and subviral particles by cryoelectron microscopy and image reconstruction. J. Cell Biol. 122:1023-1041, 1993.</ref> that contain a segmented dsRNA genome. The reovirus sigma 1 protein is a long, fiber-like molecule that extends from the virion surface<ref>Furlong, D.B., Nibert, M.L., and Fields, B.N. Sigma 1 protein of mammalian reoviruses extends from the surfaces of viral particles. J. Virol. 62:246-256, 1988.</ref> and mediates viral attachment<ref>Weiner, H.L., Ault, K.A., and Fields, B.N. Interaction of reovirus with cell surface receptors. I. Murine and human lymphocytes have a receptor for the hemagglutinin of reovirus type 3. J. Immunol. 124:2143-2148, 1980.</ref><ref>Lee, P.W.K., Hayes, E.C., and Joklik, W.K. Protein σ1 is the reovirus cell attachment protein. Virology 108:156-163, 1981.</ref>. The three human serotypes (T1, T2, and T3) differ in cell tropism, which correlates directly with receptor-binding properties of sigma 1. Sialic acid serves as an essential receptor for T3 reovirus on murine erythroleukemia (MEL) cells<ref name="Rubin1992">Rubin, D.H., Wetzel, J.D., Williams, W.V., Cohen, J.A., Dworkin, C., and Dermody, T.S. Binding of type 3 reovirus by a domain of the σ1 protein important for hemagglutination leads to infection of murine erythroleukemia cells. J. Clin. Invest. 90:2536-2542, 1992.</ref>, and it functions as a coreceptor on murine L929 (L) cells<ref name="Gentsch1985">Gentsch, J.R., and Pacitti, A.F. Effect of neuraminidase treatment of cells and effect of soluble glycoproteins on type 3 reovirus attachment to murine L cells. J. Virol. 56:356-364, 1985.</ref><ref name="Pacitti1987">Pacitti, A., and Gentsch, J.R. Inhibition of reovirus type 3 binding to host cells by sialylated glycoproteins is mediated through the viral attachment protein. J. Virol. 61:1407-1415, 1987. </ref><ref name="name4">.</ref><ref name="Rubin1992"></ref><ref name="Nibert1995">Nibert, M.L., Chappell, J.D., and Dermody, T.S. Infectious subvirion particles of reovirus type 3 Dearing exhibit a loss in infectivity and contain a cleaved σ1 protein. J. Virol. 69:5057-5067, 1995.</ref>. Residues involved in sialic acid-binding map to the center of the long fiber, close to the midpoint of the molecule<ref name="Chappell2002">Chappell, J.D., Prota, A., Dermody, T.S., and Stehle, T. Crystal structure of reovirus attachment protein σ1 reveals evolutionary relationship to adenovirus fiber. EMBO J. 21:1-11, 2002.</ref>, in a repetitive structural region known as the triple β-spiral. The T1 sigma 1 protein binds to cell-surface glycans of unknown structure.

The triple β-spiral of '''sigma 1''' functions as a trimerization domain and defines a novel carbohydrate-recognition motif. Other carbohydrate-recognition domains, such as those of the C-type lectin superfamily<ref>Weis, W.I., Taylor, M.E., and Drickamer, K. The C-type lectin superfamily in the immune system. Immunol. Rev. 163:19-34, 1998.</ref> or the sialic acid-binding domains in the Siglec family of adhesion proteins<ref>Crocker, P.R., and Varki, A. Siglecs in the immune system. Immunology 103:137-145, 2001.</ref> (see [http://glycobank.mit.edu/glycoWiki/Main_Page Siglec paradigms]), have been described, but none are formed by a repetitive, fiber-like structure such as the one present in sigma 1. In fact, the domain in sigma 1 that binds sialic acid constitutes a carbohydrate-binding “cassette” that could be endowed with altered ligand-binding properties or grafted onto other trimeric structures and used to create avidity for carbohydrates. For example, the adenovirus fiber shaft could be licensed with sialic acid-binding capacity using this approach. These properties render the sigma 1 protein unique among the structurally known glycan-binding moieties.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
CFG Participating Investigators (PIs) contributing to the understanding of sigma 1 include: Terence Dermody, Thilo Stehle

== Progress toward understanding this GBP paradigm ==

=== Carbohydrate ligands ===
Reovirus strains of all three serotypes are capable of binding to carbohydrates, which is a property mediated by viral attachment protein sigma 1<ref name="Chappell2000">Chappell, J.D., Duong, J.L., Wright, B.W., and Dermody, T.S. Identification of carbohydrate-binding domains in the attachment proteins of type 1 and type 3 reoviruses. J. Virol. 74:8472-8479, 2000.</ref>. Substantial evidence indicates that serotype 3 reoviruses bind to sialic acid, whereas the identity of carbohydrates bound by serotype 1 and 2 reoviruses is less clear. Serotype 3 reoviruses bind to alpha-linked sialic acid in either alpha2,3 or alpha2,6 linkages on a variety of cell types<ref name="Chappell2000">.</ref><ref name="Gentsch1985">.</ref><ref name="name4">Paul, R.W., Choi, A.H., and Lee, P.W.K. The a-anomeric form of sialic acid is the minimal receptor determinant recognized by reovirus. Virology 172:382-385, 1989.</ref><ref>Dermody, T.S., Nibert, M.L., Bassel-Duby, R., and Fields, B.N. Sequence diversity in S1 genes and S1 translation products of 11 serotype 3 reovirus strains. J. Virol. 64:4842-4850, 1990.</ref><ref name="Chappell1997">Chappell, J.D., Gunn, V.L., Wetzel, J.D., Baer, G.S., and Dermody, T.S. Mutations in type 3 reovirus that determine binding to sialic acid are contained in the fibrous tail domain of viral attachment protein s1. J. Virol. 71:1834-1841, 1997.</ref>. Hemagglutination by serotype 3 reoviruses is mediated by interactions with alpha-linked sialic acid on several glycosylated erythrocyte proteins such as glycophorin A<ref>Gentsch, J.R., and Pacitti, A.F. Differential interaction of reovirus type 3 with sialylated receptor components on animal cells. Virology 161:245-248, 1987.</ref><ref>Paul, R.W., and Lee, P.W.K. Glycophorin is the reovirus receptor on human erythrocytes. Virology 159:94-101, 1987.</ref>. Reovirus strain T3D binds to sialoglycophorin, but not to asialoglycophorin, with an avidity of ~ 5 x 10e-9 M<ref name="Barton2001a">Barton, E.S., Connolly, J.L., Forrest, J.C., Chappell, J.D., and Dermody, T.S. Utilization of sialic acid as a coreceptor enhances reovirus attachment by multistep adhesion strengthening. J. Biol. Chem. 276:2200-2211, 2001.</ref>.

Serotype 1 reoviruses also appear to bind to sialic acid in some contexts. Reovirus strain T1L, but not strain T3D, binds to the apical surface of microfold (M) cells, but not to enterocytes, in tissue sections of rabbit Peyer’s patches<ref name="name10">Helander, A., Silvey, K.J., Mantis, N.J., Hutchings, A.B., Chandran, K., Lucas, W.T., Nibert, M.L., and Neutra, M.R. The viral s1 protein and glycoconjugates containing a2-3-linked sialic acid are involved in type 1 reovirus adherence to M cell apical surfaces. J. Virol. 77:7964-7977, 2003.</ref>. Binding is inhibited by pre-incubation of the tissue sections with neuraminidase or with lectins that specifically recognize alpha2-3-linked sialic acid.

=== Cellular expression of GBP and ligands ===
Sialic acid serves as an essential receptor for type 3 reoviruses on murine erythroleukemia (MEL) cells<ref name="Chappell1997">.</ref><ref name="Rubin1992"></ref>. Sialic acid also functions as a coreceptor on murine L929 cells<ref name="Gentsch1985">.</ref><ref name="name4">.</ref><ref name="Rubin1992">.</ref><ref name="Pacitti1987">.</ref><ref name="Nibert1995">.</ref> and human HeLa cells<ref name="Barton2001a">.</ref>. Although not all serotype 3 strains are capable of binding to sialic acid, the majority bind to this carbohydrate.

Serotype 1 reoviruses are incapable of infecting MEL cells, which support infection only by sialic-acid-binding strains<ref name="Rubin1992">.</ref>. Serotype 1 reoviruses also are insensitive to the growth-inhibitory effects of neuraminidase treatment of L929 cells<ref name="Nibert1995">.</ref>. However, binding of serotype 1 reoviruses to intestinal M cells is diminished by neuraminidase treatment<ref name="name10">.</ref>. The explanation for this discrepancy is not known.

Reovirus employs a multi-step mechanism of viral attachment in which a low-affinity interaction with sialic acid serves to tether the virion to target cells and precedes a high-affinity interaction with JAM-A<ref name="Barton2001a">.</ref>, an immunoglobulin superfamily protein engaged by reovirus<ref name="Barton2001b">Barton, E.S., Forrest, J.C., Connolly, J.L., Chappell, J.D., Liu, Y., Schnell, F., Nusrat, A., Parkos, C.A., and Dermody, T.S. Junction adhesion molecule is a receptor for reovirus. Cell 104:441-451, 2001.</ref><ref>Prota, A.E., Campbell, J.A., Schelling, P., Forrest, J.C., Peters, T.R., Watson, M.J., Aurrand-Lions, M., Imhof, B., Dermody, T.S., and Stehle, T. Crystal structure of human junctional adhesion molecule 1: implications for reovirus binding. Proc. Natl. Acad. Sci. U. S. A. 100:5366-5371, 2003.</ref><ref>Campbell, J.A., Shelling, P., Wetzel, J.D., Johnson, E.M., Wilson, G.A.R., Forrest, J.C., Aurrand-Lions, M., Imhof, B., Stehle, T., and Dermody, T.S. Junctional adhesion molecule-A serves as a receptor for prototype and field-isolate strains of mammalian reovirus. J. Virol. 79:7967-7978, 2005.</ref>. By virtue of its rapid association rate, virus binding to sialic acid adheres the virion to the cell surface, thereby enabling it to diffuse laterally until it encounters JAM-A. Such lateral diffusion has been reported for influenza virus<ref>Sagik, B., Puck, T., and Levine, S. Quantitative aspects of the spontaneous elution of influenza virus from red cells. J. Exp. Med. 99:251-260, 1954.</ref> and phage T4<ref>Wilson, J.H., Luftig, R.B., and Wood, W.B. Interaction of bacteriophage T4 tail fiber components with a lipopolysaccharide fraction from Escherichia coli. J. Mol. Biol. 51:423-434, 1970.</ref>. After attachment, reovirus is internalized by receptor-mediated endocytosis<ref>Borsa, J., Morash, B.D., Sargent, M.D., Copps, T.P., Lievaart, P.A., and Szekely, J.G. Two modes of entry of reovirus particles into L cells. J. Gen. Virol. 45:161-170, 1979.</ref><ref>Borsa, J., Sargent, M.D., Lievaart, P.A., and Copps, T.P. Reovirus: evidence for a second step in the intracellular uncoating and transcriptase activation process. Virology 111:191-200, 1981.</ref><ref>Ehrlich, M., Boll, W., Van Oijen, A., Hariharan, R., Chandran, K., Nibert, M.L., and Kirchhausen, T. Endocytosis by random initiation and stabilization of clathrin-coated pits. Cell 118:591-605, 2004.</ref><ref name="Maginnis2006">Maginnis, M.S., Forrest, J.C., Kopecky-Bromberg, S.A., Dickeson, S.K., Santoro, S.A., Zutter, M.M., Nemerow, G.R., Bergelson, J.M., and Dermody, T.S. b1 integrin mediates internalization of mammalian reovirus. J. Virol. 80:2760-2770, 2006.</ref><ref>Sturzenbecker, L.J., Nibert, M.L., Furlong, D.B., and Fields, B.N. Intracellular digestion of reovirus particles requires a low pH and is an essential step in the viral infectious cycle. J. Virol. 61:2351-2361, 1987.</ref><ref name="Maginnis2008">Maginnis, M.S., Mainou, B.A., Derdowski, A.M., Johnson, E.M., Zent, R., and Dermody, T.S. NPXY motifs in the b1 integrin cytoplasmic tail are required for functional reovirus entry. J. Virol. 82:3181-3191, 2008.</ref> using a mechanism dependent on beta 1 integrin<ref name="Maginnis2006">.</ref><ref name="Maginnis2008">.</ref>.
=== Biosynthesis of ligands ===
Serotype 3 reovirus can bind to glycans that terminate with sialic acid in α2-3, α2-6, or α2-8 linkage. Thus, any of the known sialyl transferases ([http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/gtdb.jsp?species=Homo+sapiens&classification=SialylT&linkage_attaching=%3F&linkage_anomeric=%3F&linkage_position=%3F&linkage_base=%3F&pgname=&from=multiple&title=Multiple+Criteria+Search+Results&slideNumber=multipleQuery Human sialyltransferases]) are potentially involved in biosynthesis of target ligands.
 

=== Structure ===
Structural analysis of the C-terminal half of reovirus attachment protein sigma 1 from strain T3D (residues 246-455) reveals a trimeric structure, in which each monomer is composed of a slender tail and a compact head<ref name="Chappell2002">.</ref>. The C-terminal residues that form the head domain (310-455) consist of two Greek-key motifs that fold into a beta-barrel. The sigma 1 head domain binds to JAM-A<ref name="Barton2001b">.</ref><ref>Kirchner, E., Guglielmi, K.M., Strauss, H.M., Dermody, T.S., and Stehle, T. Structure of reovirus s1 in complex with its receptor junctional adhesion molecule-A. PLoS Path. 4:e1000235, 2008.</ref>. N-terminal residues in the crystallized fragment form a portion of the tail, residues 246-309, which consists of three beta-spiral repeats. Each repeat is composed of two short beta-strands connected by a four-residue beta-turn that has either a proline or a glycine residue at its third position<ref name="Chappell2002">.</ref>. A surface-exposed, variable loop links successive repeats, and trimerization generates an unusual triple beta-spiral motif that also is observed in the adenovirus fiber<ref>van Raaij, M.J., Mitraki, A., Lavigne, G., and Cusack, S. A triple b-spiral in the adenovirus fibre shaft reveals a new structural motif for a fibrous protein. Nature 401:935-938, 1999.</ref>, bacteriophage PRD1 P5 protein<ref>Merckel, M.C., Huiskonen, J.T., Bamford, D.H., Goldman, A., and Tuma, R. The structure of the bacteriophage PRD1 spike sheds light on the evolution of viral capsid architecture. Mol. Cell 18:161-170, 2005.</ref>, and avian reovirus attachment protein sigma C<ref>Guardado, C.P., Fox, G.C., Hermo Parrado, X.L., Llamas-Saiz, A.L., Costas, C., Martinez-Costas, J., Benavente, J., and van Raaij, M.J. Structure of the carboxy-terminal receptor-binding domain of avian reovirus fibre sigmaC. J. Mol. Biol. 354:137-149, 2005.</ref>.

In addition to the three beta-spiral repeats observed in the crystallized sigma 1 fragment, sequence analysis suggests that residues 167-249 in the T3D sigma 1 tail form an additional five N-terminal beta-spiral repeats<ref name="Chappell2002">.</ref><ref name="Guglielmi2006">Guglielmi, K.M., Johnson, E.M., Stehle, T., and Dermody, T.S. Attachment and cell entry of mammalian orthoreovirus. Curr. Top. Microbiol. Immunol. 309:1-38, 2006.</ref>. Alternatively, these residues may form a combination of beta-spiral repeats and alpha-helical coiled-coil, as suggested by sequence analysis<ref name="Chappell2002">.</ref><ref name="Guglielmi2006">.</ref><ref name="Nibert1990">Nibert, M.L., Dermody, T.S., and Fields, B.N. Structure of the reovirus cell-attachment protein: a model for the domain organization of s1. J. Virol. 64:2976-2989, 1990.</ref> and an observed narrowing in this region in a composite negative-stain electron micrograph<ref>Fraser, R.D.B., Furlong, D.B., Trus, B.L., Nibert, M.L., Fields, B.N., and Steven, A.C. Molecular structure of the cell-attachment protein of reovirus: correlation of computer-processed electron micrographs with sequence-based predictions. J. Virol. 64:2990-3000, 1990.</ref>. The structure of N-terminal residues 1-160 of sigma 1 is unknown. However, a repeating heptad sequence motif is predictive of an amphipathic alpha-helix, which likely assembles into an alpha-helical coiled-coil in the trimer<ref name="Chappell2002">.</ref><ref name="Guglielmi2006">.</ref><ref name="Nibert1990">.</ref>.

Although the structure of sigma 1 in complex with sialic acid is not yet available, studies using expressed proteins indicate that the region of T3D sigma 1 required for sialic binding resides near the midpoint of the tail, whereas a region just N-terminal to the head domain of T1L sigma 1 binds to carbohydrate<ref name="Chappell2000">.</ref>. In both T1L and T3D sigma 1, interactions with carbohydrate are mediated by a region of predicted beta-spiral<ref name="Chappell2002">.</ref>. Adaptation of non-sialic-acid-binding reoviruses to growth in MEL cells results in amino acid substitutions at residues 198, 202, and 204 of sigma 1 that confer sialic-acid-binding capacity on the resultant viruses<ref name="Chappell1997">.</ref>. Molecular modeling of the sigma 1 tail, based on available structure and sequence data, suggests that these residues are surface-exposed and proximal to one another in the predicted beta-spiral region<ref name="Chappell2002">.</ref>. Thus, residues 198, 202, and 204 are likely to contribute to a sialic-acid-binding site in T3D sigma 1.

=== Biological roles of GBP-ligand interaction ===
Sialic acid binding serves an important role in reovirus tropism and pathogenesis in vivo<ref>Barton, E.S., Youree, B.E., Ebert, D.H., Forrest, J.C., Connolly, J.L., Valyi-Nagy, T., Washington, K., Wetzel, J.D., and Dermody, T.S. Utilization of sialic acid as a coreceptor is required for reovirus-induced biliary disease. J. Clin. Invest. 111:1823-1833, 2003.</ref>. Strain T3SA+, which binds to sialic acid, and strain T3SA-, which does not bind to this carbohydrate, produce equivalent titers in the intestine of newborn mice following peroral inoculation. However, T3SA+ spreads more rapidly from the intestine to sites of secondary replication and produces higher titers in the spleen, liver, and brain. Mice infected with T3SA+, but not T3SA-, develop clinical evidence of bile duct obstruction including jaundice and steatorrhea. Liver tissue from mice infected with T3SA+ show intense inflammation focused at intrahepatic bile ducts, pathology analogous to that found in biliary atresia in human infants, and high levels of T3SA+ antigen in bile duct epithelial cells. T3SA+ binds 100-fold more efficiently than T3SA- to human cholangiocarcinoma cells. Thus, binding to sialic acid targets reovirus to bile duct epithelium and produces a disease reminiscent of infantile biliary atresia.

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=reovirus&maxresults=20 CFG database search results for "reovirus"].

=== Glycan profiling ===
Not performed.

=== Glycogene microarray ===
Sigma 1 is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.

=== Knockout mouse lines ===
Not applicable.

=== Glycan array ===
Experiments in progress. No definitive results have been obtained thus far.

== Related GBPs ==
The attachment protein of adenovirus, fiber, is a structural homolog of sigma 1. At least one adenovirus serotype (Ad37; [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=ad37&maxresults=20 CFG data]) is known to bind glycan receptors via residues in the fiber protein<ref>Burmeister WP, Guilligay D, Cusack S, Wadell G, Arnberg N: Crystal structure of species D adenovirus fiber knobs and their sialic acid binding sites. Journal of Virology 78:7727-7736, 2004.</ref>. The actual binding site is not homologous. However, information about reovirus glycan binding could also be used to engineer adenovirus fiber proteins (or other trimeric fiber-like proteins) that possess novel glycan-binding properties.

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Terence Dermody, Mavis McKenna, Thilo Stehle.

Parvovirus Minute Virus of Mice (MVM)

2011-04-09T11:57:23Z

Kurt Drickamer: /* Biological roles of GBP-ligand interaction */

The '''Parvoviridae''' is a family of small non-enveloped ssDNA viruses with a broad range of natural vertebrate and invertebrate hosts, including humans, monkeys, dogs, cats, mice, and insects. Pathogenic members cause severe disease in the young and immunocompromised adults. As examples, the newly discovered human bocavirus causes respiratory tract infections and gastroenteritis in young children and human parvovirus B19, which causes a mild rash in children infects, can cause acute severe or chronic anemia. Severe anemia due to B19 infection of an unborn baby can result in miscarriage in ~5% of pregnant women who are not immune to the virus. Non-pathogenic members, such as the Adeno-associated viruses (AAVs), are being developed for therapeutic gene deliver applications.

The ssDNA parvovirus genome, ~5000 bases, is packaged into a T=1 capsid that is ~260 Å in diameter<ref>Chapman, M.S. and M. Agbandje-McKenna, Atomic structure if viral particles., in Parvoviruses, J.R. Kerr, et al., Editors. 2006, Edward Aenold Ltd. New York: New York. p. 107-123.</ref>. The capsid is assembled from 60 copies (in total) of the common C-terminal region (~520 aa) of two to four overlapping capsid viral proteins (VPs), depending on the family member, with the larger proteins having N-terminal extensions which are not required for capsid assembly, but perform other functions in the life cycle, including a PLA2 domain required for endosomal escape during cellular trafficking. Thus these capsids are assembled from essentially one protein which is responsible for performing the multitude of functions required for successful host infection, including host cell receptor attachment, an essential first step in the life cycle<ref>Agbandje-McKenna, M. and M.S. Chapman, Correlating structure with function in the viral capsid, in Parvoviruses, J.R. Kerr, et al., Editors. 2006, Edward Arnold, New York: New York.</ref>. While the cell surface receptors are not known for the majority of the Parvoviridae, recognition of cell surface glycans, in the context of proteins or lipids, have been reported to be an important first step in infection. This glycan recognition also plays a role in (I) tissue tropism and pathogenicity differences between highly homologous strains for several pathogenic members and (II) tissue tropism and transduction efficiency in viral gene delivery vectors. Thus characterizing the interaction(s) of these viruses with their receptors is important for understanding the capsid determinants of tissue tropism and pathogenicity, and for manipulating the capsids for improved efficacy in corrective gene delivery applications. Minute Virus of Mice (MVM), is assembled from three VPs, VP1, VP2, and VP3, with the entire sequence of the smallest VP3 contained within VP2 which is in turn contained with VP1; VP1 has a unique N-terminal PLA2 region. VP3, which is only generated from VP2 following genome packaging, forms the majority of the capsid protein content, at ~90%, and contains the receptor recognition site. Significantly, this receptor-recognition site is only created in the assembled capsid with amino acid contributions from icosahedral symmetry related VPs<ref name="Kontou 2005">Kontou, M., L. Govindasamy, H.-J. Nam, N. Bryant, A. L. Llamas-Saiz, C. Foces-Foces, E. Hernando, M.-P Rubio, R. McKenna, J. M. Almendral., M. Agbandje-McKenna. 2005. Structural determinants of tissue tropism and in vivo pathogenicity for the parvovirus minute virus of mice. J. Virol., 79:10931-10943.</ref>.

The parvoviruses provide an excellent example of genomic economy in the coding of a “single” viral protein which assembles a multifunctional capsid, including a receptor recognition site. '''MVM''' has proved to be an ideal model for studying the capsid determinant of tissue tropism, pathogenicity, and host range adaption dictated by glycan receptor interaction(s) for this family. Interaction with cell surface sialic acid, in the context of a glycoprotein, is an essential first step in cellular recognition and tropism by MVM<ref name="Cotmore 1987">Cotmore, S. F., and P. Tattersall. 1987. The autonomously replicating parvoviruses of vertebrates. Adv. Virus Res. 33:91–174. </ref><ref name="Lopez-Bueno 2006">López-Bueno, A, M-P. Rubio, N. Bryant, R. McKenna, M. Agbandje-McKenna, J. M. Almendral. 2006. Host-selected amino acid changes at the sialic acid binding pocket of the parvovirus capsid modulate cell binding affinity and determine virulence. J. Virol., 80: 1563-1573. </ref>. Two homologous MVM strains (MVMp, the prototype non-pathogenic strain and MVMi, the immunosuppressive pathogenic strain) that are 97% identical have pronounced differences in tissue tropism and in vivo pathogenesis<ref>Brownstein, D. G., A. L. Smith, R. O. Jacoby, E. A. Johnson, G. Hansen, and P. Tattersall. 1991. Pathogenesis of infection with a virulent allotropic variant of minute virus of mice and regulation by host genotype. Lab. Investig. 65:357–363.</ref><ref>Brownstein, D. G., A. L. Smith, E. A. Johnson, D. J. Pintel, L. K. Naeger, and P. Tattersall. 1992. The pathogenesis of infection with minute virus of mice depends on expression of the small nonstructural protein NS2 and on the genotype of the allotropic determinants VP1 and VP2. J. Virol. 66:3118– 3124. </ref><ref>Ramı´rez, J. C., A. Fiaren, and J. M. Almendral. 1996. Parvovirus minute virus of mice strain I multiplication and pathogenesis in the newborn mouse brain are restricted to proliferative areas and to migratory cerebral young neurons. J. Virol. 70:8109–8116.</ref><ref>Segovia, J. C., J. A. Bueren, and J. M. Almendral. 1995. Myeloid depression follows infection of susceptible newborn mice with the parvovirus minute virus of mice (strain i). J. Virol. 69:3229–3232.</ref><ref>Segovia, J. C., J. M. Gallego, J. A. Bueren, and J. M. Almendral. 1999. Severe leukopenia and dysregulated erythropoiesis in SCID mice persistently infected with the parvovirus minute virus of mice. J. Virol. 73:1774–1784. </ref>. Their phenotypes are associated with one or two VP amino acid differences resulting in local structural variations that alter MVM – infectious sialic acid receptor interactions and utilization<ref name="Nam 2006">Nam, H.-J., B. Gurda-Whitaker, W. Y. Gan, S. Ilaria, R. McKenna, P. Mehta, R. A. Alvarez, M. Agbandje-McKenna. 2006. Identification of the sialic acid structures recognized by minuterole of binding affinity in virulence adaptation. J. Bio. Chem., 281:25670-25677.</ref><ref name="Lopez-Bueno 2006"/>. Studies of the MVMp, in which virulent mutations were observed, also provided information on capsid adaptations, associated with altered receptor affinity, which confer a pathogenic phenotype<ref name="Nam 2006"/>. In addition, MVM has served as a model for studying capsid adaptations, involving the sialic acid receptor recognition site, which enables the infection of a new host<ref>Etingov I, R. Itah, M. Mincberg, A. Keren-Naus, H.-J. Nam, M. Agbandje-McKenna, C. Davis C. 2008. An extension of the Minute Virus of Mice tissue tropism. Virology, 379:245-255.</ref>. While it is known that a limited number of amino acids differences can also dictate tropism and pathogenicity disparities between homologous strains of other Parvoviridae members, unlike MVM, these have not been extensively studied with respect to the contribution of glycans interactions in dictating these differences.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
* CFG Participating Investigators (PIs) contributing to the understanding of MVM include: Mavis McKenna
* CFG PIs contributing to the understanding of AAV capsid include: Aravind Asokan, Regine Heilbronn

== Progress toward understanding this GBP paradigm ==

=== Carbohydrate ligands ===
MVM interacts with cell surface sialic acid, in the context of a glycoprotein<ref name="Cotmore 1987"/><ref name="Lopez-Bueno 2006"/>. This glycan is also recognized by several members of the Parvoviridae, including H1 (rat parvovirus) and members of the AAV[13] (and unpublished data).
 

=== Cellular expression of GBP and ligands ===
MVM is a member of the Parvoviridae, a group of small non-enveloped ssDNA family of viruses with a T=1 icosahedral capsid. Members of this family infect a broad range of vertebrate and invertebrate hosts, including humans, dogs, cats, mice, and insects and have tropism for different tissues and organs In vitro MVM strains grow in mouse fibroblasts, T lymphocytes, and hematopoietic precursors. In vivo MVM replicates in many organs, including the kidneys, liver, and the brain (for MVM strain i)
 

=== Biosynthesis of ligands ===
Sialylated glycoproteins recognized by MVM are synthesized by host cells. The enzyme required for biosynthesis of the type 2 poly N-acetyllactosamine chains and modification with sialic acid or with sialic acid and fucose, creating the Lewisx epitope, have been defined ([http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/geMolecule.jsp?slideNumber=slide7 poly N-acetyllactosamine extension biosynthesis]). Gangliosides, sialylated oligosaccharides, are synthesized by the host by well defined pathways ([http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/geMolecule.jsp?slideNumber=slide9 Glucosylceramide biosynthesis]).
 

=== Structure ===

MVM is assembled from three VPs, VP1, VP2, and VP3, with the entire sequence of the smallest VP3 contained within VP2 which is in turn contained with VP1; VP1 has a unique N-terminal PLA2 region. VP3, which is only generated from VP2 following genome packaging, forms the majority of the capsid protein content, at ~90%, and contains the receptor recognition site. Significantly, this receptor-recognition site is only created in the assembled capsid with amino acid contributions from icosahedral symmetry related VPs<ref name="Kontou 2005"/>.
 [[File:MVMMonoCapsid.jpg]]
 
The glycan structures below have been observed to interact with MVM capsids using the CFG glycan array
 
[[File:structuresGD3SiaLN.jpg]]
 

=== Biological roles of GBP-ligand interaction ===
Interaction with cell surface sialic acid, in the context of a glycoprotein, is an essential first step in cellular recognition and tropism by MVM<ref name="Cotmore 1987"/><ref name="Lopez-Bueno 2006"/>. Glycan recognition by members of the Parvoviridae family dictates tissue tropism and is involved in tissue tropism and pathogenicity differences between highly homologous strains for several pathogenic members.
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=parvovirus&maxresults=20 CFG database search results for "parvovirus"].

Three CFG resources have been used in the characterization of MVM glycan interactions and ''in vitro'' tissue tropism.
=== Glycan profiling ===
TThe CFG performed glycan profiling of three different cell lines, A9 fibroblasts, EL4T lymphocytes, and NB324K cells used for in vitro studies of MVM, in order to correlate the glycan screening results with the glycans present on the cells that are permissive to the MVM strains (unpublished data).

=== Glycogene microarray ===
MVM is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
N/A
 

=== Glycan array ===
The glycan recognition properties of the two MVM strains (click [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_GLYCAN_v3_35_08102004 here]), as well as virulent mutants arising from ''in vivo'' studies of MVMp, were further defined using the CFG glycan array<ref name="Nam 2006"/> (and unpublished data). These capsids were the first intact virus capsids to be screened by the CFG. This was done using plate arrays versions 2 and 3<ref name="Nam 2006"/>. The glycans identified in the array screening were then provided by the CFG for X-ray crystallographic studies to map the receptor binding site on the virus capsids (unpublished data). Mutations of capsid surface amino acids residues at the mapped binding site results in reduced sialic acid affinity<ref name="Lopez-Bueno 2006"/><ref name="Nam 2006"/>. CFG PIs have also used the CFG glycan array to screen AAV capsids. To see all glycan array results for MVM, click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=MVM&cat=coreh here].

== Related GBPs ==
Other parvovirus GBPs have been studied by the CFG, including H1 (rat parvovirus) and several AAV serotypes: AAV1 [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=AAV1&maxresults=20 (CFG data)], AAV2, AAV4-AAV9<ref name="Wu 2006">Wu Z, E. Miller E, M. Agbandje-McKenna, R. J. Samulski. 2006. {alpha}2,3 and {alpha}2,6 N Linked Sialic Acids Facilitate Efficient Binding and Transduction by Adeno-Associated Virus Types 1 and 6. J. Virol., 80:9093-9103. </ref> (and unpublished data; CFG data: [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=AAV5&maxresults=20 AAV5,] [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=AAV6&maxresults=20 AAV6,] [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=AAV7&cat=coreh AAV7,] [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=AAV8&maxresults=20 AAV8,] [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=AAV9&maxresults=20 AAV9.]) Glycan array analyses have been used to identify glycans recognized by the capsids of these viruses, which includes terminal sialic acid containing oligosaccharides as well as those which terminate in galatose <ref name="Wu 2006"/>(and unpublished data).

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Mavis Agbandje-McKenna, Thilo Stehle

Parvovirus Minute Virus of Mice (MVM)

2011-04-09T11:50:16Z

Kurt Drickamer: /* Biosynthesis of ligands */

The '''Parvoviridae''' is a family of small non-enveloped ssDNA viruses with a broad range of natural vertebrate and invertebrate hosts, including humans, monkeys, dogs, cats, mice, and insects. Pathogenic members cause severe disease in the young and immunocompromised adults. As examples, the newly discovered human bocavirus causes respiratory tract infections and gastroenteritis in young children and human parvovirus B19, which causes a mild rash in children infects, can cause acute severe or chronic anemia. Severe anemia due to B19 infection of an unborn baby can result in miscarriage in ~5% of pregnant women who are not immune to the virus. Non-pathogenic members, such as the Adeno-associated viruses (AAVs), are being developed for therapeutic gene deliver applications.

The ssDNA parvovirus genome, ~5000 bases, is packaged into a T=1 capsid that is ~260 Å in diameter<ref>Chapman, M.S. and M. Agbandje-McKenna, Atomic structure if viral particles., in Parvoviruses, J.R. Kerr, et al., Editors. 2006, Edward Aenold Ltd. New York: New York. p. 107-123.</ref>. The capsid is assembled from 60 copies (in total) of the common C-terminal region (~520 aa) of two to four overlapping capsid viral proteins (VPs), depending on the family member, with the larger proteins having N-terminal extensions which are not required for capsid assembly, but perform other functions in the life cycle, including a PLA2 domain required for endosomal escape during cellular trafficking. Thus these capsids are assembled from essentially one protein which is responsible for performing the multitude of functions required for successful host infection, including host cell receptor attachment, an essential first step in the life cycle<ref>Agbandje-McKenna, M. and M.S. Chapman, Correlating structure with function in the viral capsid, in Parvoviruses, J.R. Kerr, et al., Editors. 2006, Edward Arnold, New York: New York.</ref>. While the cell surface receptors are not known for the majority of the Parvoviridae, recognition of cell surface glycans, in the context of proteins or lipids, have been reported to be an important first step in infection. This glycan recognition also plays a role in (I) tissue tropism and pathogenicity differences between highly homologous strains for several pathogenic members and (II) tissue tropism and transduction efficiency in viral gene delivery vectors. Thus characterizing the interaction(s) of these viruses with their receptors is important for understanding the capsid determinants of tissue tropism and pathogenicity, and for manipulating the capsids for improved efficacy in corrective gene delivery applications. Minute Virus of Mice (MVM), is assembled from three VPs, VP1, VP2, and VP3, with the entire sequence of the smallest VP3 contained within VP2 which is in turn contained with VP1; VP1 has a unique N-terminal PLA2 region. VP3, which is only generated from VP2 following genome packaging, forms the majority of the capsid protein content, at ~90%, and contains the receptor recognition site. Significantly, this receptor-recognition site is only created in the assembled capsid with amino acid contributions from icosahedral symmetry related VPs<ref name="Kontou 2005">Kontou, M., L. Govindasamy, H.-J. Nam, N. Bryant, A. L. Llamas-Saiz, C. Foces-Foces, E. Hernando, M.-P Rubio, R. McKenna, J. M. Almendral., M. Agbandje-McKenna. 2005. Structural determinants of tissue tropism and in vivo pathogenicity for the parvovirus minute virus of mice. J. Virol., 79:10931-10943.</ref>.

The parvoviruses provide an excellent example of genomic economy in the coding of a “single” viral protein which assembles a multifunctional capsid, including a receptor recognition site. '''MVM''' has proved to be an ideal model for studying the capsid determinant of tissue tropism, pathogenicity, and host range adaption dictated by glycan receptor interaction(s) for this family. Interaction with cell surface sialic acid, in the context of a glycoprotein, is an essential first step in cellular recognition and tropism by MVM<ref name="Cotmore 1987">Cotmore, S. F., and P. Tattersall. 1987. The autonomously replicating parvoviruses of vertebrates. Adv. Virus Res. 33:91–174. </ref><ref name="Lopez-Bueno 2006">López-Bueno, A, M-P. Rubio, N. Bryant, R. McKenna, M. Agbandje-McKenna, J. M. Almendral. 2006. Host-selected amino acid changes at the sialic acid binding pocket of the parvovirus capsid modulate cell binding affinity and determine virulence. J. Virol., 80: 1563-1573. </ref>. Two homologous MVM strains (MVMp, the prototype non-pathogenic strain and MVMi, the immunosuppressive pathogenic strain) that are 97% identical have pronounced differences in tissue tropism and in vivo pathogenesis<ref>Brownstein, D. G., A. L. Smith, R. O. Jacoby, E. A. Johnson, G. Hansen, and P. Tattersall. 1991. Pathogenesis of infection with a virulent allotropic variant of minute virus of mice and regulation by host genotype. Lab. Investig. 65:357–363.</ref><ref>Brownstein, D. G., A. L. Smith, E. A. Johnson, D. J. Pintel, L. K. Naeger, and P. Tattersall. 1992. The pathogenesis of infection with minute virus of mice depends on expression of the small nonstructural protein NS2 and on the genotype of the allotropic determinants VP1 and VP2. J. Virol. 66:3118– 3124. </ref><ref>Ramı´rez, J. C., A. Fiaren, and J. M. Almendral. 1996. Parvovirus minute virus of mice strain I multiplication and pathogenesis in the newborn mouse brain are restricted to proliferative areas and to migratory cerebral young neurons. J. Virol. 70:8109–8116.</ref><ref>Segovia, J. C., J. A. Bueren, and J. M. Almendral. 1995. Myeloid depression follows infection of susceptible newborn mice with the parvovirus minute virus of mice (strain i). J. Virol. 69:3229–3232.</ref><ref>Segovia, J. C., J. M. Gallego, J. A. Bueren, and J. M. Almendral. 1999. Severe leukopenia and dysregulated erythropoiesis in SCID mice persistently infected with the parvovirus minute virus of mice. J. Virol. 73:1774–1784. </ref>. Their phenotypes are associated with one or two VP amino acid differences resulting in local structural variations that alter MVM – infectious sialic acid receptor interactions and utilization<ref name="Nam 2006">Nam, H.-J., B. Gurda-Whitaker, W. Y. Gan, S. Ilaria, R. McKenna, P. Mehta, R. A. Alvarez, M. Agbandje-McKenna. 2006. Identification of the sialic acid structures recognized by minuterole of binding affinity in virulence adaptation. J. Bio. Chem., 281:25670-25677.</ref><ref name="Lopez-Bueno 2006"/>. Studies of the MVMp, in which virulent mutations were observed, also provided information on capsid adaptations, associated with altered receptor affinity, which confer a pathogenic phenotype<ref name="Nam 2006"/>. In addition, MVM has served as a model for studying capsid adaptations, involving the sialic acid receptor recognition site, which enables the infection of a new host<ref>Etingov I, R. Itah, M. Mincberg, A. Keren-Naus, H.-J. Nam, M. Agbandje-McKenna, C. Davis C. 2008. An extension of the Minute Virus of Mice tissue tropism. Virology, 379:245-255.</ref>. While it is known that a limited number of amino acids differences can also dictate tropism and pathogenicity disparities between homologous strains of other Parvoviridae members, unlike MVM, these have not been extensively studied with respect to the contribution of glycans interactions in dictating these differences.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
* CFG Participating Investigators (PIs) contributing to the understanding of MVM include: Mavis McKenna
* CFG PIs contributing to the understanding of AAV capsid include: Aravind Asokan, Regine Heilbronn

== Progress toward understanding this GBP paradigm ==

=== Carbohydrate ligands ===
MVM interacts with cell surface sialic acid, in the context of a glycoprotein<ref name="Cotmore 1987"/><ref name="Lopez-Bueno 2006"/>. This glycan is also recognized by several members of the Parvoviridae, including H1 (rat parvovirus) and members of the AAV[13] (and unpublished data).
 

=== Cellular expression of GBP and ligands ===
MVM is a member of the Parvoviridae, a group of small non-enveloped ssDNA family of viruses with a T=1 icosahedral capsid. Members of this family infect a broad range of vertebrate and invertebrate hosts, including humans, dogs, cats, mice, and insects and have tropism for different tissues and organs In vitro MVM strains grow in mouse fibroblasts, T lymphocytes, and hematopoietic precursors. In vivo MVM replicates in many organs, including the kidneys, liver, and the brain (for MVM strain i)
 

=== Biosynthesis of ligands ===
Sialylated glycoproteins recognized by MVM are synthesized by host cells. The enzyme required for biosynthesis of the type 2 poly N-acetyllactosamine chains and modification with sialic acid or with sialic acid and fucose, creating the Lewisx epitope, have been defined ([http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/geMolecule.jsp?slideNumber=slide7 poly N-acetyllactosamine extension biosynthesis]). Gangliosides, sialylated oligosaccharides, are synthesized by the host by well defined pathways ([http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/geMolecule.jsp?slideNumber=slide9 Glucosylceramide biosynthesis]).
 

=== Structure ===

MVM is assembled from three VPs, VP1, VP2, and VP3, with the entire sequence of the smallest VP3 contained within VP2 which is in turn contained with VP1; VP1 has a unique N-terminal PLA2 region. VP3, which is only generated from VP2 following genome packaging, forms the majority of the capsid protein content, at ~90%, and contains the receptor recognition site. Significantly, this receptor-recognition site is only created in the assembled capsid with amino acid contributions from icosahedral symmetry related VPs<ref name="Kontou 2005"/>.
 [[File:MVMMonoCapsid.jpg]]
 
The glycan structures below have been observed to interact with MVM capsids using the CFG glycan array
 
[[File:structuresGD3SiaLN.jpg]]
 

=== Biological roles of GBP-ligand interaction ===
Glycan recognition by members of the Parvoviridae family dictates tissue tropism and is involved in tissue tropism and pathogenicity differences between highly homologous strains for several pathogenic members.
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=parvovirus&maxresults=20 CFG database search results for "parvovirus"].

Three CFG resources have been used in the characterization of MVM glycan interactions and ''in vitro'' tissue tropism.
=== Glycan profiling ===
TThe CFG performed glycan profiling of three different cell lines, A9 fibroblasts, EL4T lymphocytes, and NB324K cells used for in vitro studies of MVM, in order to correlate the glycan screening results with the glycans present on the cells that are permissive to the MVM strains (unpublished data).

=== Glycogene microarray ===
MVM is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
N/A
 

=== Glycan array ===
The glycan recognition properties of the two MVM strains (click [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_GLYCAN_v3_35_08102004 here]), as well as virulent mutants arising from ''in vivo'' studies of MVMp, were further defined using the CFG glycan array<ref name="Nam 2006"/> (and unpublished data). These capsids were the first intact virus capsids to be screened by the CFG. This was done using plate arrays versions 2 and 3<ref name="Nam 2006"/>. The glycans identified in the array screening were then provided by the CFG for X-ray crystallographic studies to map the receptor binding site on the virus capsids (unpublished data). Mutations of capsid surface amino acids residues at the mapped binding site results in reduced sialic acid affinity<ref name="Lopez-Bueno 2006"/><ref name="Nam 2006"/>. CFG PIs have also used the CFG glycan array to screen AAV capsids. To see all glycan array results for MVM, click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=MVM&cat=coreh here].

== Related GBPs ==
Other parvovirus GBPs have been studied by the CFG, including H1 (rat parvovirus) and several AAV serotypes: AAV1 [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=AAV1&maxresults=20 (CFG data)], AAV2, AAV4-AAV9<ref name="Wu 2006">Wu Z, E. Miller E, M. Agbandje-McKenna, R. J. Samulski. 2006. {alpha}2,3 and {alpha}2,6 N Linked Sialic Acids Facilitate Efficient Binding and Transduction by Adeno-Associated Virus Types 1 and 6. J. Virol., 80:9093-9103. </ref> (and unpublished data; CFG data: [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=AAV5&maxresults=20 AAV5,] [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=AAV6&maxresults=20 AAV6,] [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=AAV7&cat=coreh AAV7,] [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=AAV8&maxresults=20 AAV8,] [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=AAV9&maxresults=20 AAV9.]) Glycan array analyses have been used to identify glycans recognized by the capsids of these viruses, which includes terminal sialic acid containing oligosaccharides as well as those which terminate in galatose <ref name="Wu 2006"/>(and unpublished data).

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Mavis Agbandje-McKenna, Thilo Stehle

Polyomavirus capsid protein (VP1)

2011-04-09T11:35:19Z

Kurt Drickamer: /* Glycan profiling */

'''Polyomaviruses''' are a group of small, non-enveloped DNA viruses that can infect birds, rodents, and primates. Members of the group include simian virus 40 (SV40) and murine polyomavirus (mPyV) as well as a number of human polyomaviruses such as the BK and JC viruses (BKV and JCV, respectively). Recently, a new human polyomavirus was found to be linked to Merkel cell carcinoma, an aggressive type of skin cancer<ref name=" Feng H1096">
Feng H, Shuda M, Chang Y, Moore PS: Clonal integration of a polyomavirus in human Merkel cell carcinoma. Science 2008, 319:1096-1100.</ref>. All polyomavirus capsids are constructed from 360 copies of the major coat protein, VP1, arranged in pentamers on a T=7 icosahedral lattice<ref>Liddington RC, Yan Y, Moulai J, Sahli R, Benjamin TL, Harrison SC: Structure of simian virus 40 at 3.8-A resolution. Nature 1991, 354:278-284.</ref>. The cell-surface receptors for SV40, mPyV, BKV, JCV, and possibly other polyomaviruses are gangliosides, which are complex, sialic acid-containing sphingolipids that reside primarily in lipid rafts. SV40 uses the ganglioside GM1, BKV binds GD1b and GT1b, and mPyV attaches to GD1a and GT1b<ref name=" Tsai B4346 ">Tsai B, Gilbert JM, Stehle T, Lencer W, Benjamin TL, Rapoport TA: Gangliosides are receptors for murine polyoma virus and SV40. Embo J 2003, 22:4346-4355.</ref><ref name=" Low JA1361 ">Low JA, Magnuson B, Tsai B, Imperiale MJ: Identification of gangliosides GD1b and GT1b as receptors for BK virus. J Virol 2006, 80:1361-1366.</ref>. The glycan-binding properties of the human polyomaviruses are currently being investigated.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
CFG Participating Investigators (PIs) contributing to the understanding of VP1 include: Niklas Arnberg, Ten Feizi, Thilo Stehle

== Progress toward understanding this GBP paradigm ==

=== Carbohydrate ligands ===

The polyomaviruses use a range of glycans for attachment and cell entry, depending on the virus type. For the simian virus SV40 and murine polyomavirus, the receptors have been identified as gangliosides GM1 and GT1b/GD1a<ref name=" Tsai B4346 "></ref>, respectively. The human BK polyomavirus binds to sialylated glycans that include gangliosides GD1b and GT1b <ref name=" Low JA1361 "></ref><ref name=" Dugan AS 14442">Dugan AS, Eash S, Atwood WJ (2005) An N-linked glycoprotein with alpha(2,3)-linked sialic acid is a receptor for BK virus. J Virol 79: 14442-14445.</ref>. The human JC polyomavirus uses sialylated glycans<ref>Dugan AS, Gasparovic ML, Atwood WJ (2008) Direct correlation between sialic acid binding and infection of cells by two human polyomaviruses (JC virus and BK virus). J Virol 82: 2560-2564.</ref><ref>Komagome R, Sawa H, Suzuki T, Suzuki Y, Tanaka S, et al. (2002) Oligosaccharides as receptors for JC virus. J Virol 76: 12992-13000.</ref><ref>Liu CK, Wei G, Atwood WJ (1998) Infection of glial cells by the human polyomavirus JC is mediated by an N-linked glycoprotein containing terminal alpha(2-6)-linked sialic acids. J Virol 72: 4643-4649.</ref>as well as the serotonin receptor 5HT2aR<ref>Elphick GF, Querbes W, Jordan JA, Gee GV, Eash S, et al. (2004) The human polyomavirus, JCV, uses serotonin receptors to infect cells. Science 306: 1380-1383.</ref>as attachment receptors. The receptors for other polyomaviruses, such as the recently identified Merkel Cell Polyomavirus<ref name=" Feng H1096"></ref>, have not been characterized, but at least some of these are likely to also use glycans for cell attachment. Participating investigators (PIs) of the CFG have made major contributions to our understanding of the structural and functional basis of attachment of polyomaviruses to their receptors<ref name=" Tsai B4346 "></ref><ref name=" Stehle T 5139">Stehle T, Harrison SC: High-resolution structure of a polyomavirus VP1-oligosaccharide complex: implications for assembly and receptor binding. The EMBO Journal 1997, 16:5139-5148.</ref><ref>Stehle T, Harrison SC (1996) Crystal structures of murine polyomavirus in complex with straight-chain and branched-chain sialyloligosaccharide receptor fragments. Structure, Folding and Design 4: 183-194.</ref><ref name=" Neu U 5219">Neu U, Woellner K, Gauglitz G, Stehle T: Structural basis of GM1 ganglioside recognition by simian virus 40. Proc Natl Acad Sci U S A 2008, 105:5219-5224.</ref><ref> Neu U, Stehle T, Atwood WJ (2009) The Polyomaviridae: Contributions of virus structure to our understanding of virus receptors and infectious entry. Virology 384: 389-399.</ref>

=== Cellular expression of GBP and ligands ===

Varies, depending on virus type:
 
JC Polyomavirus: persists in the kidney <ref> Dorries K (1998) Molecular biology and pathogenesis of human polyomavirus infections. Dev Biol Stand 94: 71-79.</ref>. In immunocompromised individuals, the virus infects glial cells, including astrocytes and the myelin-producing oligodendrocytes, resulting in the fatal disease PML (Progressive Multifocal Leukoecenlopathy) <ref>Silverman L, Rubinstein LJ (1965) Electron microscopic observations on a case of progressive multifocal leukoencephalopathy. Acta Neuropathol 5: 215-224.</ref><ref> Seth P, Diaz F, Major EO (2003) Advances in the biology of JC virus and induction of progressive multifocal leukoencephalopathy. J Neurovirol 9: 236-246.</ref><ref> Khalili K, White MK (2006) Human demyelinating disease and the polyomavirus JCV. Mult Scler 12: 133-142.</ref>.
 
BK Polyomavirus: Infects genitourinary tract <ref> Hirsch HH, Steiger J (2003) Polyomavirus BK. Lancet Infect Dis 3: 611-623.</ref><ref> Shinohara T, Matsuda M, Cheng SH, Marshall J, Fujita M, et al. (1993) BK virus infection of the human urinary tract. J Med Virol 41: 301-305.</ref><ref> Nickeleit V, Hirsch HH, Binet IF, Gudat F, Prince O, et al. (1999) Polyomavirus infection of renal allograft recipients: from latent infection to manifest disease. J Am Soc Nephrol 10: 1080-1089.</ref>, causes PVN (Polyomavirus-Associated Nephropathy).

=== Biosynthesis of ligands ===
Gangliosides, sialylated oligosaccharides, are synthesized by the host by well defined pathways ([http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/geMolecule.jsp?slideNumber=slide9 Glucosylceramide biosynthetic pathways]).
 

=== Structure ===
Crystal structures are available for complete mPyV particles and for mPyV VP1 pentamers in complex with ganglioside receptor fragments<ref>Stehle T, Yan Y, Benjamin TL, Harrison SC: Structure of murine polyomavirus complexed with an oligosaccharide receptor fragment. Nature 1994, 369:160-163.</ref><ref name=" Stehle T 5139"></ref> as well as for the SV40 VP1 pentamer in complex with GM1 <ref name=" Neu U 5219"></ref>. The available structures show that '''VP1''' forms a scaffold that can modulate the specificity of interaction through small changes in surface loops. We plan to generate a set of perhaps five different structures that highlight conserved as well as non-conserved interactions with different gangliosides, thereby providing a platform for understanding and altering receptor-binding properties. This work is important, as there are few known examples of viral proteins from non-enveloped viruses with a common fold for which subtle modulations of surface properties result in altered glycan-binding specificities. 

A selection of gangliosides is shown below. GM1, GD1a, GD1b and GT1b are used by several polyomaviruses as receptors.
 
[[File:gangliosidesGM1.jpg]]

=== Biological roles of GBP-ligand interaction ===
Cell attachment, required for entry and infectivity, determinant of tropism<ref name=" Tsai B4346 "></ref> <ref name=" Dugan AS 14442"></ref><ref name=" Low JA1361 "></ref>. Recent data show that the structure of ganglioside GM1 determines SV40-induced membrane invagination and infection<ref>Ewers H, Romer W, Smith AE, Bacia K, Dmitrieff S, et al. (2010) GM1 structure determines SV40-induced membrane invagination and infection. Nat Cell Biol 12: 11-18; sup pp 11-12.</ref>. Subsequent entry processes depend for many polyomaviruses on proteins in the endoplasmic reticulum<ref> Schelhaas M, Malmstrom J, Pelkmans L, Haugstetter J, Ellgaard L, et al. (2007) Simian Virus 40 depends on ER protein folding and quality control factors for entry into host cells. Cell 131: 516-529.</ref>.
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=polyoma&maxresults=20 CFG database search results for "polyoma"].

=== Glycan profiling ===
N/A
 

=== Glycogene microarray ===
VP1 is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
None
 

=== Glycan array ===
The CFG glycan array was used to determine the [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_PA_v2_405_07312006 ligand specificity for SV40]. This information was then used to crystallize SV40 VP1 in complex with the oligosaccharide portion of the GM1 gangloside. To see all glycan array results for VP1, click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=VP1&cat=coreh here].

== Related GBPs ==
Functionally (but not structurally) related are the pentameric B proteins of the AB5-type toxins, such as [[Subtilase cytotoxin (SubAB)]]. These also interact with gangliosides.

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Mavis McKenna, Thilo Stehle

Polyomavirus capsid protein (VP1)

2011-04-09T11:35:04Z

Kurt Drickamer: /* Knockout mouse lines */

'''Polyomaviruses''' are a group of small, non-enveloped DNA viruses that can infect birds, rodents, and primates. Members of the group include simian virus 40 (SV40) and murine polyomavirus (mPyV) as well as a number of human polyomaviruses such as the BK and JC viruses (BKV and JCV, respectively). Recently, a new human polyomavirus was found to be linked to Merkel cell carcinoma, an aggressive type of skin cancer<ref name=" Feng H1096">
Feng H, Shuda M, Chang Y, Moore PS: Clonal integration of a polyomavirus in human Merkel cell carcinoma. Science 2008, 319:1096-1100.</ref>. All polyomavirus capsids are constructed from 360 copies of the major coat protein, VP1, arranged in pentamers on a T=7 icosahedral lattice<ref>Liddington RC, Yan Y, Moulai J, Sahli R, Benjamin TL, Harrison SC: Structure of simian virus 40 at 3.8-A resolution. Nature 1991, 354:278-284.</ref>. The cell-surface receptors for SV40, mPyV, BKV, JCV, and possibly other polyomaviruses are gangliosides, which are complex, sialic acid-containing sphingolipids that reside primarily in lipid rafts. SV40 uses the ganglioside GM1, BKV binds GD1b and GT1b, and mPyV attaches to GD1a and GT1b<ref name=" Tsai B4346 ">Tsai B, Gilbert JM, Stehle T, Lencer W, Benjamin TL, Rapoport TA: Gangliosides are receptors for murine polyoma virus and SV40. Embo J 2003, 22:4346-4355.</ref><ref name=" Low JA1361 ">Low JA, Magnuson B, Tsai B, Imperiale MJ: Identification of gangliosides GD1b and GT1b as receptors for BK virus. J Virol 2006, 80:1361-1366.</ref>. The glycan-binding properties of the human polyomaviruses are currently being investigated.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
CFG Participating Investigators (PIs) contributing to the understanding of VP1 include: Niklas Arnberg, Ten Feizi, Thilo Stehle

== Progress toward understanding this GBP paradigm ==

=== Carbohydrate ligands ===

The polyomaviruses use a range of glycans for attachment and cell entry, depending on the virus type. For the simian virus SV40 and murine polyomavirus, the receptors have been identified as gangliosides GM1 and GT1b/GD1a<ref name=" Tsai B4346 "></ref>, respectively. The human BK polyomavirus binds to sialylated glycans that include gangliosides GD1b and GT1b <ref name=" Low JA1361 "></ref><ref name=" Dugan AS 14442">Dugan AS, Eash S, Atwood WJ (2005) An N-linked glycoprotein with alpha(2,3)-linked sialic acid is a receptor for BK virus. J Virol 79: 14442-14445.</ref>. The human JC polyomavirus uses sialylated glycans<ref>Dugan AS, Gasparovic ML, Atwood WJ (2008) Direct correlation between sialic acid binding and infection of cells by two human polyomaviruses (JC virus and BK virus). J Virol 82: 2560-2564.</ref><ref>Komagome R, Sawa H, Suzuki T, Suzuki Y, Tanaka S, et al. (2002) Oligosaccharides as receptors for JC virus. J Virol 76: 12992-13000.</ref><ref>Liu CK, Wei G, Atwood WJ (1998) Infection of glial cells by the human polyomavirus JC is mediated by an N-linked glycoprotein containing terminal alpha(2-6)-linked sialic acids. J Virol 72: 4643-4649.</ref>as well as the serotonin receptor 5HT2aR<ref>Elphick GF, Querbes W, Jordan JA, Gee GV, Eash S, et al. (2004) The human polyomavirus, JCV, uses serotonin receptors to infect cells. Science 306: 1380-1383.</ref>as attachment receptors. The receptors for other polyomaviruses, such as the recently identified Merkel Cell Polyomavirus<ref name=" Feng H1096"></ref>, have not been characterized, but at least some of these are likely to also use glycans for cell attachment. Participating investigators (PIs) of the CFG have made major contributions to our understanding of the structural and functional basis of attachment of polyomaviruses to their receptors<ref name=" Tsai B4346 "></ref><ref name=" Stehle T 5139">Stehle T, Harrison SC: High-resolution structure of a polyomavirus VP1-oligosaccharide complex: implications for assembly and receptor binding. The EMBO Journal 1997, 16:5139-5148.</ref><ref>Stehle T, Harrison SC (1996) Crystal structures of murine polyomavirus in complex with straight-chain and branched-chain sialyloligosaccharide receptor fragments. Structure, Folding and Design 4: 183-194.</ref><ref name=" Neu U 5219">Neu U, Woellner K, Gauglitz G, Stehle T: Structural basis of GM1 ganglioside recognition by simian virus 40. Proc Natl Acad Sci U S A 2008, 105:5219-5224.</ref><ref> Neu U, Stehle T, Atwood WJ (2009) The Polyomaviridae: Contributions of virus structure to our understanding of virus receptors and infectious entry. Virology 384: 389-399.</ref>

=== Cellular expression of GBP and ligands ===

Varies, depending on virus type:
 
JC Polyomavirus: persists in the kidney <ref> Dorries K (1998) Molecular biology and pathogenesis of human polyomavirus infections. Dev Biol Stand 94: 71-79.</ref>. In immunocompromised individuals, the virus infects glial cells, including astrocytes and the myelin-producing oligodendrocytes, resulting in the fatal disease PML (Progressive Multifocal Leukoecenlopathy) <ref>Silverman L, Rubinstein LJ (1965) Electron microscopic observations on a case of progressive multifocal leukoencephalopathy. Acta Neuropathol 5: 215-224.</ref><ref> Seth P, Diaz F, Major EO (2003) Advances in the biology of JC virus and induction of progressive multifocal leukoencephalopathy. J Neurovirol 9: 236-246.</ref><ref> Khalili K, White MK (2006) Human demyelinating disease and the polyomavirus JCV. Mult Scler 12: 133-142.</ref>.
 
BK Polyomavirus: Infects genitourinary tract <ref> Hirsch HH, Steiger J (2003) Polyomavirus BK. Lancet Infect Dis 3: 611-623.</ref><ref> Shinohara T, Matsuda M, Cheng SH, Marshall J, Fujita M, et al. (1993) BK virus infection of the human urinary tract. J Med Virol 41: 301-305.</ref><ref> Nickeleit V, Hirsch HH, Binet IF, Gudat F, Prince O, et al. (1999) Polyomavirus infection of renal allograft recipients: from latent infection to manifest disease. J Am Soc Nephrol 10: 1080-1089.</ref>, causes PVN (Polyomavirus-Associated Nephropathy).

=== Biosynthesis of ligands ===
Gangliosides, sialylated oligosaccharides, are synthesized by the host by well defined pathways ([http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/geMolecule.jsp?slideNumber=slide9 Glucosylceramide biosynthetic pathways]).
 

=== Structure ===
Crystal structures are available for complete mPyV particles and for mPyV VP1 pentamers in complex with ganglioside receptor fragments<ref>Stehle T, Yan Y, Benjamin TL, Harrison SC: Structure of murine polyomavirus complexed with an oligosaccharide receptor fragment. Nature 1994, 369:160-163.</ref><ref name=" Stehle T 5139"></ref> as well as for the SV40 VP1 pentamer in complex with GM1 <ref name=" Neu U 5219"></ref>. The available structures show that '''VP1''' forms a scaffold that can modulate the specificity of interaction through small changes in surface loops. We plan to generate a set of perhaps five different structures that highlight conserved as well as non-conserved interactions with different gangliosides, thereby providing a platform for understanding and altering receptor-binding properties. This work is important, as there are few known examples of viral proteins from non-enveloped viruses with a common fold for which subtle modulations of surface properties result in altered glycan-binding specificities. 

A selection of gangliosides is shown below. GM1, GD1a, GD1b and GT1b are used by several polyomaviruses as receptors.
 
[[File:gangliosidesGM1.jpg]]

=== Biological roles of GBP-ligand interaction ===
Cell attachment, required for entry and infectivity, determinant of tropism<ref name=" Tsai B4346 "></ref> <ref name=" Dugan AS 14442"></ref><ref name=" Low JA1361 "></ref>. Recent data show that the structure of ganglioside GM1 determines SV40-induced membrane invagination and infection<ref>Ewers H, Romer W, Smith AE, Bacia K, Dmitrieff S, et al. (2010) GM1 structure determines SV40-induced membrane invagination and infection. Nat Cell Biol 12: 11-18; sup pp 11-12.</ref>. Subsequent entry processes depend for many polyomaviruses on proteins in the endoplasmic reticulum<ref> Schelhaas M, Malmstrom J, Pelkmans L, Haugstetter J, Ellgaard L, et al. (2007) Simian Virus 40 depends on ER protein folding and quality control factors for entry into host cells. Cell 131: 516-529.</ref>.
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=polyoma&maxresults=20 CFG database search results for "polyoma"].

=== Glycan profiling ===
N/A

 

=== Glycogene microarray ===
VP1 is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===
None
 

=== Glycan array ===
The CFG glycan array was used to determine the [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_PA_v2_405_07312006 ligand specificity for SV40]. This information was then used to crystallize SV40 VP1 in complex with the oligosaccharide portion of the GM1 gangloside. To see all glycan array results for VP1, click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=VP1&cat=coreh here].

== Related GBPs ==
Functionally (but not structurally) related are the pentameric B proteins of the AB5-type toxins, such as [[Subtilase cytotoxin (SubAB)]]. These also interact with gangliosides.

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Mavis McKenna, Thilo Stehle

Polyomavirus capsid protein (VP1)

2011-04-09T11:34:43Z

Kurt Drickamer: /* Glycan profiling */

'''Polyomaviruses''' are a group of small, non-enveloped DNA viruses that can infect birds, rodents, and primates. Members of the group include simian virus 40 (SV40) and murine polyomavirus (mPyV) as well as a number of human polyomaviruses such as the BK and JC viruses (BKV and JCV, respectively). Recently, a new human polyomavirus was found to be linked to Merkel cell carcinoma, an aggressive type of skin cancer<ref name=" Feng H1096">
Feng H, Shuda M, Chang Y, Moore PS: Clonal integration of a polyomavirus in human Merkel cell carcinoma. Science 2008, 319:1096-1100.</ref>. All polyomavirus capsids are constructed from 360 copies of the major coat protein, VP1, arranged in pentamers on a T=7 icosahedral lattice<ref>Liddington RC, Yan Y, Moulai J, Sahli R, Benjamin TL, Harrison SC: Structure of simian virus 40 at 3.8-A resolution. Nature 1991, 354:278-284.</ref>. The cell-surface receptors for SV40, mPyV, BKV, JCV, and possibly other polyomaviruses are gangliosides, which are complex, sialic acid-containing sphingolipids that reside primarily in lipid rafts. SV40 uses the ganglioside GM1, BKV binds GD1b and GT1b, and mPyV attaches to GD1a and GT1b<ref name=" Tsai B4346 ">Tsai B, Gilbert JM, Stehle T, Lencer W, Benjamin TL, Rapoport TA: Gangliosides are receptors for murine polyoma virus and SV40. Embo J 2003, 22:4346-4355.</ref><ref name=" Low JA1361 ">Low JA, Magnuson B, Tsai B, Imperiale MJ: Identification of gangliosides GD1b and GT1b as receptors for BK virus. J Virol 2006, 80:1361-1366.</ref>. The glycan-binding properties of the human polyomaviruses are currently being investigated.

== CFG Participating Investigators contributing to the understanding of this paradigm ==
CFG Participating Investigators (PIs) contributing to the understanding of VP1 include: Niklas Arnberg, Ten Feizi, Thilo Stehle

== Progress toward understanding this GBP paradigm ==

=== Carbohydrate ligands ===

The polyomaviruses use a range of glycans for attachment and cell entry, depending on the virus type. For the simian virus SV40 and murine polyomavirus, the receptors have been identified as gangliosides GM1 and GT1b/GD1a<ref name=" Tsai B4346 "></ref>, respectively. The human BK polyomavirus binds to sialylated glycans that include gangliosides GD1b and GT1b <ref name=" Low JA1361 "></ref><ref name=" Dugan AS 14442">Dugan AS, Eash S, Atwood WJ (2005) An N-linked glycoprotein with alpha(2,3)-linked sialic acid is a receptor for BK virus. J Virol 79: 14442-14445.</ref>. The human JC polyomavirus uses sialylated glycans<ref>Dugan AS, Gasparovic ML, Atwood WJ (2008) Direct correlation between sialic acid binding and infection of cells by two human polyomaviruses (JC virus and BK virus). J Virol 82: 2560-2564.</ref><ref>Komagome R, Sawa H, Suzuki T, Suzuki Y, Tanaka S, et al. (2002) Oligosaccharides as receptors for JC virus. J Virol 76: 12992-13000.</ref><ref>Liu CK, Wei G, Atwood WJ (1998) Infection of glial cells by the human polyomavirus JC is mediated by an N-linked glycoprotein containing terminal alpha(2-6)-linked sialic acids. J Virol 72: 4643-4649.</ref>as well as the serotonin receptor 5HT2aR<ref>Elphick GF, Querbes W, Jordan JA, Gee GV, Eash S, et al. (2004) The human polyomavirus, JCV, uses serotonin receptors to infect cells. Science 306: 1380-1383.</ref>as attachment receptors. The receptors for other polyomaviruses, such as the recently identified Merkel Cell Polyomavirus<ref name=" Feng H1096"></ref>, have not been characterized, but at least some of these are likely to also use glycans for cell attachment. Participating investigators (PIs) of the CFG have made major contributions to our understanding of the structural and functional basis of attachment of polyomaviruses to their receptors<ref name=" Tsai B4346 "></ref><ref name=" Stehle T 5139">Stehle T, Harrison SC: High-resolution structure of a polyomavirus VP1-oligosaccharide complex: implications for assembly and receptor binding. The EMBO Journal 1997, 16:5139-5148.</ref><ref>Stehle T, Harrison SC (1996) Crystal structures of murine polyomavirus in complex with straight-chain and branched-chain sialyloligosaccharide receptor fragments. Structure, Folding and Design 4: 183-194.</ref><ref name=" Neu U 5219">Neu U, Woellner K, Gauglitz G, Stehle T: Structural basis of GM1 ganglioside recognition by simian virus 40. Proc Natl Acad Sci U S A 2008, 105:5219-5224.</ref><ref> Neu U, Stehle T, Atwood WJ (2009) The Polyomaviridae: Contributions of virus structure to our understanding of virus receptors and infectious entry. Virology 384: 389-399.</ref>

=== Cellular expression of GBP and ligands ===

Varies, depending on virus type:
 
JC Polyomavirus: persists in the kidney <ref> Dorries K (1998) Molecular biology and pathogenesis of human polyomavirus infections. Dev Biol Stand 94: 71-79.</ref>. In immunocompromised individuals, the virus infects glial cells, including astrocytes and the myelin-producing oligodendrocytes, resulting in the fatal disease PML (Progressive Multifocal Leukoecenlopathy) <ref>Silverman L, Rubinstein LJ (1965) Electron microscopic observations on a case of progressive multifocal leukoencephalopathy. Acta Neuropathol 5: 215-224.</ref><ref> Seth P, Diaz F, Major EO (2003) Advances in the biology of JC virus and induction of progressive multifocal leukoencephalopathy. J Neurovirol 9: 236-246.</ref><ref> Khalili K, White MK (2006) Human demyelinating disease and the polyomavirus JCV. Mult Scler 12: 133-142.</ref>.
 
BK Polyomavirus: Infects genitourinary tract <ref> Hirsch HH, Steiger J (2003) Polyomavirus BK. Lancet Infect Dis 3: 611-623.</ref><ref> Shinohara T, Matsuda M, Cheng SH, Marshall J, Fujita M, et al. (1993) BK virus infection of the human urinary tract. J Med Virol 41: 301-305.</ref><ref> Nickeleit V, Hirsch HH, Binet IF, Gudat F, Prince O, et al. (1999) Polyomavirus infection of renal allograft recipients: from latent infection to manifest disease. J Am Soc Nephrol 10: 1080-1089.</ref>, causes PVN (Polyomavirus-Associated Nephropathy).

=== Biosynthesis of ligands ===
Gangliosides, sialylated oligosaccharides, are synthesized by the host by well defined pathways ([http://www.functionalglycomics.org/glycomics/molecule/jsp/glycoEnzyme/geMolecule.jsp?slideNumber=slide9 Glucosylceramide biosynthetic pathways]).
 

=== Structure ===
Crystal structures are available for complete mPyV particles and for mPyV VP1 pentamers in complex with ganglioside receptor fragments<ref>Stehle T, Yan Y, Benjamin TL, Harrison SC: Structure of murine polyomavirus complexed with an oligosaccharide receptor fragment. Nature 1994, 369:160-163.</ref><ref name=" Stehle T 5139"></ref> as well as for the SV40 VP1 pentamer in complex with GM1 <ref name=" Neu U 5219"></ref>. The available structures show that '''VP1''' forms a scaffold that can modulate the specificity of interaction through small changes in surface loops. We plan to generate a set of perhaps five different structures that highlight conserved as well as non-conserved interactions with different gangliosides, thereby providing a platform for understanding and altering receptor-binding properties. This work is important, as there are few known examples of viral proteins from non-enveloped viruses with a common fold for which subtle modulations of surface properties result in altered glycan-binding specificities. 

A selection of gangliosides is shown below. GM1, GD1a, GD1b and GT1b are used by several polyomaviruses as receptors.
 
[[File:gangliosidesGM1.jpg]]

=== Biological roles of GBP-ligand interaction ===
Cell attachment, required for entry and infectivity, determinant of tropism<ref name=" Tsai B4346 "></ref> <ref name=" Dugan AS 14442"></ref><ref name=" Low JA1361 "></ref>. Recent data show that the structure of ganglioside GM1 determines SV40-induced membrane invagination and infection<ref>Ewers H, Romer W, Smith AE, Bacia K, Dmitrieff S, et al. (2010) GM1 structure determines SV40-induced membrane invagination and infection. Nat Cell Biol 12: 11-18; sup pp 11-12.</ref>. Subsequent entry processes depend for many polyomaviruses on proteins in the endoplasmic reticulum<ref> Schelhaas M, Malmstrom J, Pelkmans L, Haugstetter J, Ellgaard L, et al. (2007) Simian Virus 40 depends on ER protein folding and quality control factors for entry into host cells. Cell 131: 516-529.</ref>.
 

== CFG resources used in investigations ==
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the [http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=polyoma&maxresults=20 CFG database search results for "polyoma"].

=== Glycan profiling ===
N/A

 

=== Glycogene microarray ===
VP1 is not represented on the CFG microarrays, which only contain probes for mouse and human glycogenes.
 

=== Knockout mouse lines ===

 
None

=== Glycan array ===
The CFG glycan array was used to determine the [http://www.functionalglycomics.org/glycomics/HServlet?operation=view&sideMenu=no&psId=primscreen_PA_v2_405_07312006 ligand specificity for SV40]. This information was then used to crystallize SV40 VP1 in complex with the oligosaccharide portion of the GM1 gangloside. To see all glycan array results for VP1, click [http://www.functionalglycomics.org/glycomics/search/jsp/result.jsp?query=VP1&cat=coreh here].

== Related GBPs ==
Functionally (but not structurally) related are the pentameric B proteins of the AB5-type toxins, such as [[Subtilase cytotoxin (SubAB)]]. These also interact with gangliosides.

== References ==
<references/>

== Acknowledgements ==
The CFG is grateful to the following PIs for their contributions to this wiki page: Mavis McKenna, Thilo Stehle