Nagai T
Department of Laboratory Medicine, Fukushima Medical College.
Rinsho Byori. 1996 Dec;44(12):1119-24.
Fibronectin is a major and multifunctional cell adhesive extracellular matrix protein. Many studies have been carried out to reveal its structures and functions. One of the most important question was the cell adhesive structures on the molecule and how to associate with cell surface receptors. It was striking that very short amino acid sequence Arg-Gly-Asp (RGD) in the central cell binding domain of fibronectin was determined as minimum cell adhesive sequence. However, other data indicate that additional subregions besides the RGD motif are required for its cell adhesive activity mediated by alpha 5 beta 1 fibronectin receptor. This putative synergistic site, second site, was analyzed by site directed mutagenesis studies, homology scanning using intramolecular chimeras and epitope mapping using inhibitory monoclonal antibodies. Those studies cleared that the functional sequence, Pro-His-Ser-Arg-Asn (PHSRN), synergistically enhances the cell-adhesive activity of RGD motif depends on the activation state of the integrin.
纤连蛋白是一种主要的多功能细胞黏附细胞外基质蛋白。已经开展了许多研究来揭示其结构和功能。其中一个最重要的问题是该分子上的细胞黏附结构以及如何与细胞表面受体结合。令人惊讶的是，纤连蛋白中央细胞结合域中非常短的氨基酸序列精氨酸-甘氨酸-天冬氨酸（RGD）被确定为最小细胞黏附序列。然而，其他数据表明，除RGD基序外的其他亚区域对于由α5β1纤连蛋白受体介导的其细胞黏附活性是必需的。这个假定的协同位点，即第二位点，通过定点诱变研究、使用分子内嵌合体的同源性扫描以及使用抑制性单克隆抗体的表位作图进行了分析。这些研究明确了功能性序列脯氨酸-组氨酸-丝氨酸-精氨酸-天冬酰胺（PHSRN）协同增强RGD基序的细胞黏附活性取决于整合素的激活状态。
