Fibronectin and vitronectin regulate the organization of their respective Arg-Gly-Asp adhesion receptors in cultured human endothelial cells.
Fibronectin and vitronectin regulate the organization of their respective Arg-Gly-Asp adhesion receptors in cultured human endothelial cells.
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DOI：
10.1083/jcb.107.3.1215
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发表时间：
1988-09
期刊：
影响因子：
--
通讯作者：
Marchisio PC
中科院分区：
文献类型：
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作者：
Dejana E;Colella S;Conforti G;Abbadini M;Gaboli M;Marchisio PC
人脐静脉内皮细胞（ECs）在体外粘附于细胞外基质蛋白，包括纤维连接蛋白（fn）和玻璃体连接蛋白（vn）。fn和vn的特异性受体先前已被鉴定。这些受体属于一个膜糖蛋白家族，其特点是(a)是两个非共价连接亚基的跨膜复合物，(b)在其各自的配体上识别三肽Arg- Gly-Asp。在本文中，我们研究了vn和fn如何控制其各自受体在ECs表面的组织。研究发现，单个受体的聚类和随后的局部接触组织只发生在内皮细胞暴露于特定配体时，而不会发生在相反的配体上。当内皮细胞在fn + vn混合基质上培养时，两种受体簇的形状略有不同，并且发现两种受体的共定位。vn或fn受体抗体在其各自的底物上选择性地抑制粘附。这两种受体的聚集先于血管蛋白与局灶接触和应力纤维形成的关联。此外，在缺乏相关fn受体的情况下，vn受体能够诱导膜-微丝相互作用复合物的组织。总的来说，这些结果表明单个基质配体只诱导其各自的膜受体聚集。只有一种受体的聚集能够支持随后形成的局灶接触和相关细胞骨架蛋白的局部组装。
Human umbilical vein endothelial cells (ECs) adhere in vitro to proteins of the extracellular matrix including fibronectin (fn) and vitronectin (vn). Specific receptors for fn and vn have been previously characterized. These receptors belong to a family of membrane glycoproteins characterized (a) by being a transmembrane complex of two noncovalently linked subunits and (b) by recognizing the tripeptide Arg- Gly-Asp on their respective ligands. In this paper we investigated how vn and fn control the organization of their respective receptors over the surface of ECs. It was found that the clustering of individual receptors and the organization thereafter of focal contacts occurred only when ECs were exposed to the specific ligand and did not occur on the opposite ligand. The shape of receptor clusters was slightly different and a colocalization of the two receptors was found when ECs were cultured on a mixed matrix of fn plus vn. Adhesion was selectively inhibited by vn or fn receptor antibodies on their respective substrates. The clustering of both receptors preceded the association of vinculin with focal contacts and stress fiber formation. Also, the vn receptor, in the absence of associated fn receptor, was capable of inducing the organization of the membrane-microfilament interaction complex. Overall, these results indicate that individual matrix ligands induce only the clustering of their respective membrane receptors. The clustering of only one receptor is capable of supporting the subsequent formation of focal contacts and the local assembly of related cytoskeletal proteins.