Cheresh D A, Smith J W, Cooper H M, Quaranta V
Department of Immunology, Research Institute of Scripps Clinic, La Jolla, California 92037.
Cell. 1989 Apr 7;57(1):59-69. doi: 10.1016/0092-8674(89)90172-4.
Carcinoma cells express a novel integrin involved in cell adhesion to vitronectin, but not to fibrinogen or von Willebrand factor, whereas melanoma and endothelial cells express a vitronectin receptor (alpha v beta 3) that promotes cell attachment to all of these matrix components. The integrin responsible for this adhesive phenotype of carcinoma cells is composed of an alpha subunit that is indistinguishable from the alpha v of the vitronectin receptor and a beta subunit (beta x) that is distinct from any known integrin beta subunit. Accordingly, Northern blot analysis identifies an mRNA for alpha v, but not for beta 3 in carcinoma cells. This receptor appears to mediate cell adhesion to vitronectin as well as fibronectin since an antibody directed to its alpha subunit blocked carcinoma cell adhesion to both of these matrix proteins. These results suggest that homologous integrins with identical alpha subunits and structurally distinct beta subunits can account for the functional recognition of different matrixes by two cell types.
癌细胞表达一种新型整合素，该整合素参与细胞与玻连蛋白的黏附，但不参与与纤维蛋白原或血管性血友病因子的黏附，而黑色素瘤细胞和内皮细胞表达一种玻连蛋白受体（αvβ3），该受体促进细胞与所有这些基质成分的附着。负责癌细胞这种黏附表型的整合素由一个与玻连蛋白受体的αv无法区分的α亚基和一个与任何已知整合素β亚基不同的β亚基（βx）组成。因此，Northern印迹分析在癌细胞中鉴定出αv的mRNA，但未鉴定出β3的mRNA。该受体似乎介导细胞与玻连蛋白以及纤连蛋白的黏附，因为针对其α亚基的抗体可阻断癌细胞与这两种基质蛋白的黏附。这些结果表明，具有相同α亚基和结构不同的β亚基的同源整合素可以解释两种细胞类型对不同基质的功能识别。
