{PDOC00927} {PS01207; GLYPICAN} {BEGIN} *********************** * Glypicans signature * *********************** Glypicans [1,2] are a family of heparan sulfate proteoglycans which are anchored to cell membranes by a glycosylphosphatidylinositol (GPI) linkage. Structurally, these proteins consist of three separate domains: a) A signal sequence; b) An extracellular domain of about 500 residues that contains 12 conserved cysteines probably involved in disulfide bonds and which also contains the sites of attachment of the heparan sulfate glycosaminoglycan side chains; c) A C-terminal hydrophobic region which is post-translationally removed after formation of the GPI-anchor. The proteins known to belong to this family are: - Glypican 1 (GPC1). - Glypican 2 (GPC2) or cerebroglycan. - Glypican 3 (GPC3) or OCI-5. In man, defects in GPC3 are the cause of a X- linked genetic disease, Simpson-Galabi-Behmel syndrome (SGBS). - Glypican 4 (GPC4) or K-glypican. - Glypican 5 (GPC5). - Glypican 6 (GPC6). - Drosophila protein dally. The signature pattern that we developed for glypicans is located in the central section of the extracellular domain and contains five of the conserved cysteines. -Consensus pattern: C-x(2)-C-x-[GS]-[LIVM]-x(4)-P-C-x(2)-[FY]-C-x(2)-[LIVM]- x(2)-G-C [The C's are probably involved in a disulfide bonds] -Sequences known to belong to this class detected by the pattern: ALL, except for dally. -Other sequence(s) detected in Swiss-Prot: NONE. -Last update: April 2006 / Pattern revised. [ 1] Weksberg R., Squire J.A., Templeton D.M. "Glypicans: a growing trend." Nat. Genet. 12:225-227(1996). PubMed=8589707; DOI=10.1038/ng0396-225 [ 2] Watanabe K., Yamada H., Yamaguchi Y. "K-glypican: a novel GPI-anchored heparan sulfate proteoglycan that is highly expressed in developing brain and kidney." J. Cell Biol. 130:1207-1218(1995). PubMed=7657705 -------------------------------------------------------------------------------- PROSITE is copyrighted by the SIB Swiss Institute of Bioinformatics and distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND 4.0) License, see https://prosite.expasy.org/prosite_license.html -------------------------------------------------------------------------------- {END}