Functions of Cell Surface Heparan Sulfate Proteoglycans

Bernfleld, M., Gotte, M., Park, P.W., Reizes, O., Fitzgerald, M.L., Lincecum, J., Zako, M. (1999) Functions of cell surface heparan sulfate proteoglycans. Annu. Rev. Biochem. 68, 729-777. Extensive review of the biological roles of heparan sulfate. 

Functions of Cell Surface Heparan Sulfate Proteoglycans... 

Yanagishita, M., and Hascall, V. C., 1992. Cell surface heparan sulfate proteoglycans./. Biol. Chem. 267 9451-9454. lozzo, R. V., 1999. The biology of small leucine-rich proteoglycans Functional network of interactive proteins./ Biol. Chem. 274 18843—18846. 

Heparan sulfate proteoglycans and the coreceptors have been localized predominantly to the basolateral surface of WD HAE cells (47), which correlates with preferential transduction of these cells when vector is applied to the basolateral membrane relative to the apical membrane. However, binding studies of radiolabeled AAV-2 have shown only a four- to sevenfold reduction in binding to the cal membrane of WD HAE in culture as compared to the basal membrane. Because gene transfer efficiency was 200- fold greater following basal application than for luminal qiplication, the existence of apical membrane receptors for AAV-2 that are not functional for vector expression have been proposed (47,94). 

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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