Identification of receptors for laminin

层粘连蛋白-5定位于皮肤基底膜，支持表皮-真皮连接的结构稳定性，调节多种细胞功能。在这里，我们利用哺乳动物细胞中的重组蛋白和合成肽来分析α3链羧基末端球状结构域(LG1LG5域)的肝素结合和细胞黏附活性。永生化人角质形成细胞系HaCat细胞和人真皮成纤维细胞与LG4结构域特异性结合，并呈剂量依赖关系。通过抑制研究，细胞与LG4中的#75‘结合是由细胞表面硫酸乙酰肝素蛋白多糖介导的。固相分析表明Syndecan-2与#75‘相互作用。克隆了表达与#75‘和LG4特异性结合的Syndecan的293T细胞。这些数据表明，Syndecan介导了细胞与层粘连蛋白α3LG4结构域的黏附。

The laminin-5 is localized at skin basement membrane and supports structural stability of epidermo-dermal linkage and regulates various cellular functions. Here we analyze the heparin binding and cell adhesion activities in α3 chain carboxyl terminal globular domain (LG1〜LG5 domain) utilizing recombinant proteins made in mammalian cells as well as synthetic peptides. Immortalized human keratinocyte line HaCat cells and human dermal fibroblasts bound to LG4 domain specifically and in a dose-dependent manner. By inhibition studies, cell binding to the #75' within LG4 was mediated by cell surface heparan sulfate proteoglycan. Solid-phase assays demonstrated that syndecan-2 interacted with the #75'. Cloned 293T cells expressing syndecan specifically attached to #75' as well as to LG4. These data indicate that syndecan mediate cell adhesion to the laminin α3 LG4 domain.