Heperan Sulfate Proteoglycan Mediates Cell-Cell Adhesion

M. Ishihara
1996 Trends in glycoscience and glycotechnology  
The syndecans comprise a family of heparan sulfate bearing transmembrane proteoglycans that arise from four distinct genes within mammals. Except for the glycosaminoglycan attachment sites, the extracellular domains of the syndecans are highly divergent. In contrast, the transmembrane and cytoplasmic domains are highly conversed both as members of the syndecan family and among different species. Syndecans are known to regulate various cell behaviors by binding cells to the extracellular matrix
more » ... nd by binding growth factors etc. Syndecan-1, via its heparan sulfate chains, binds to a variety of extracellular matrix macromolecules including collagens, fibronectin, thrombospondin, and tenascin etc. In tissues, syndecan-1 localizes to the basolateral surface of simple epithelia and during B cell differentiation, syndecan-1 is expressed only at times when B cells associate with the extracellular matrix. The affinity of syndecan-1 for the matrix, its ability to bind cells to the matrix, and its pattern of expression are consistent with its proposed role as a receptor for the extracellular matrix. Thus, syndecans participate in cell matrix adhesion. In addition, it has been widely speculated that syndecans participate in cell-cell adhesion. This is due to a number of reports indicating that syndecans are often found at sites of cell-cell contact. However, there has been no direct evidence demonstrating that syndecans can mediate cell-cell adhesion. The authors of this paper have shown the first evidence that syndecan-1 or other members of the syndecan family can mediate cell-cell adhesion. The authors found that following their transfection with cDNA for syndecan-1 or syndecan-4, human B lymphoid cell line (ARH-77) forms large multicellular aggregates in suspension culture and stain intensely for the syndecans at sites of cellcell contact. Both parental cells and vector-transfectants failed to aggregate extensively. Using rotation-mediated cell aggre-
doi:10.4052/tigg.8.55 fatcat:7vnnlaooybbjxcr4q7ucnyi2ky