Heparan Sulfate Synthases and Related Genes
Heparan sulfate (HS) and heparin (HP) are linear polysaccharides composed of repeating disaccharide units, [-4GlcAβ1(IdoAα1)-4GlcNAcα1-]n, where GlcA, IdoA, and GlcNAc represent glucuronic acid, iduronic acid, and N-acetylglucosamine, respectively, which are covalently linked to specific core proteins through the glycosaminoglycan (GAG)-protein linkage region tetrasaccharide, GlcAβ1-3Galβ1-3Galβ1-4Xylβ1-O-Ser (where Gal, Xyl, and Ser stand for galactose, xylose, and serine, respectively) forming proteoglycans (PGs). HS and HP backbones are synthesized by five glycosyltransferases, human exostosin (EXT) family members, which are associated with hereditary multiple exostoses (HME). Subsequently, HS and HP are modified by GlcNAc N-deacetylase/Nsulfotransferase, GlcA C5-epimerase, and O-sulfotransferases, resulting in the formation of functional domains and/or sequences (Mizumoto et al. 2005).
KeywordsHeparan Sulfate Hereditary Multiple Exostosis Heparan Sulfate Chain Iduronic Acid Repeat Disaccharide Unit
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- Kitagawa H, Izumikawa T, Mizuguchi S, Dejima K, Nomura KH, Egusa N, Taniguchi F, Tamura J, Gengyo-Ando K, Mitani S, Nomura K, Sugahara K (2007) Expression of rib-1, a Caenorhabditis elegans homolog of the human tumor suppressor EXT genes is indispensable for heparan sulfate synthesis and embryonic morphogenesis. J Biol Chem 282:8533–8544PubMedCrossRefGoogle Scholar