Reactome | Heparan sulfate/heparin (HS-GAG) metabolism

Heparan sulfate/heparin (HS-GAG) metabolism

Stable Identifier

R-HSA-1638091

Type

Pathway

Species

Homo sapiens

ReviewStatus

5/5

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Heparan sulfate/heparin (HS-GAG) metabolism

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Proteins carrying a heparan sulfate (HS) chain are called heparan sulfate proteoglycans (HSPG). Free HS is usually stored within the secretory granules of mast cells or cleaved from HSPGs on degradation. HS is a member of the glycosaminoglycan (GAG) family and consists of the variably sulfated repeating disaccharide units heparan (Ido-GlcNAc) or heparosan (GlcA-GlcNAc). Higher degrees of sulfation and iduronic acid content in the polysaccharide chain confers the name heparin rather than heparan sulfate to the chain. Two or three HS chains attach to a core protein on the cell surface or in the extracellular matrix (Sasisekharan & Venkataraman 2000). HS bound to a core protein can regulate many biological processes such as angiogenesis, blood coagulation and tumour metastasis (Stringer & Gallagher 1997, Tumova et al. 2000). Degradation of HS is required to maintain a natural turnover of GAGs. Defects in the degradative enzymes result in lysosomal storage diseases, where GAGs build up rather than being broken down and having pathological effects (Ballabio & Gieselmann 2009).

Literature References

PubMed ID	Title	Journal	Year
9251237	Heparan sulphate Gallagher, JT, Stringer, SE	Int J Biochem Cell Biol	1997
10716625	Heparan sulfate proteoglycans on the cell surface: versatile coordinators of cellular functions Tumova, S, Woods, A, Couchman, JR	Int J Biochem Cell Biol	2000
11102866	Heparin and heparan sulfate: biosynthesis, structure and function Venkataraman, G, Sasisekharan, R	Curr Opin Chem Biol	2000
19111581	Lysosomal disorders: from storage to cellular damage Gieselmann, V, Ballabio, A	Biochim Biophys Acta	2009