Extracellular matrix heparan sulfate proteoglycan

Extracellular Matrix Heparan Sulfate Proteoglycans and Their Functions... 

The most complete structural information about sulfate-dependent protein interactions is available from extensive studies on the many interactions of heparan sulfate proteoglycans (HSPGs). Via their covalently attached heparan sulfate chains, HSPGs bind to a large array of growth factors, cytokines, chemokines, extracellular matrix proteins, cell-cell adhesion molecules, viral attachment receptors, blood coagulation components, and lipid carrier molecules [18 21], Among the functions served by these interactions are ... 

Gallagher JT, Heparan sulfate proteoglycans the control of cell growth. In Extracellular Matrix, Comper W, Editor. 1996, Harwood Academic Publishers, pp. 230-245. 

Type I collagen can interact with various other molecules in the extracellular matrix and on the cell surface. Cell receptors of type I collagen have been identified and include the heterodimeric integrin family receptors, ctl, 0 2, olO, and ol 1, especially o2/3l, the receptor tyrosine kinase discoidin domain receptor (DDR), and the heparan sulfate membrane proteoglycan syndecan family... 

Proteoglycans bind to a variety of different proteins and polysaccharides. For example, the large extracellular matrix protein tenascin, which is important to adhesion, cell migration, and proliferation, binds to chondroitin sulfate proteoglycans such as neurocan.225 Syndecan, a transmembrane proteoglycan, carries both chondroitin and heparan sulfate chains, enabling it to interact with a variety of proteins that mediate cell-matrix adhesion.185... 

Proteoglycans are major components of the extracellular matrix in animal cells. They are composed of core proteins and glycosaminoglycan polysaccharides. Heparin and heparan sulfate are the most complex glycosaminoglycans, a family of molecules that also includes chon-... 

These are either integral membrane proteoglycans or are linked to the membrane via a phosphatidylinositol moiety. They appear to serve as receptors for growth factors and other components of the extracellular matrix, for cell-matrix and cell-cell interactions, and as receptors for other cell-cell interaction molecules. Usually it is the heparan sulfate glycosaminoglycan that is the interactive agent, although chondroitin sulfate and the core proteins have also been shown to function in this manner under some conditions. In addition there are reports of free glycosaminoglycan chains found in cell surfaces [147]. Their source and functions are unclear. 

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