McLean J W, Vestal D J, Cheresh D A, Bodary S C
Department of Cardiovascular Research, Genentech Inc., South San Francisco, California 94080.
J Biol Chem. 1990 Oct 5;265(28):17126-31.
A novel integrin receptor involved in cell adhesion to the matrix protein vitronectin has recently been described from a human lung epithelial-derived cell line (Cheresh, D. A., Smith, J. W., Cooper, H. M., and Quaranta, V. (1989) Cell 57, 59-69). This receptor has an alpha subunit that appears identical to the alpha v of the vitronectin receptor alpha v beta 3 expressed in melanoma and endothelial cells, but is complexed with a distinct beta subunit, beta 5. cDNA clones coding for beta 5 have been isolated and used to determine the mRNA and amino acid sequence of this new subunit. A 3.3-kilobase mRNA was found to code for a mature protein of 775 amino acid residues with a hydrophobic leader sequence of 24 amino acids. A 56% identity was found between the beta 5 and beta 3 protein sequences, making them the most closely related of the integrin beta subunits. Polymerase chain reaction abundance analysis revealed that alpha v and beta 5 mRNAs were found in seven very different cell lines, compared with beta 3 mRNA which was found in only three of the them, indicating that this new integrin receptor may be widely distributed.
最近，从人肺上皮衍生细胞系中发现了一种参与细胞与基质蛋白玻连蛋白黏附的新型整合素受体（切雷什，D.A.，史密斯，J.W.，库珀，H.M.，和夸兰塔，V.（1989年）《细胞》57卷，59 - 69页）。该受体的α亚基似乎与在黑色素瘤和内皮细胞中表达的玻连蛋白受体αvβ3的αv相同，但与一个不同的β亚基β5形成复合物。已分离出编码β5的cDNA克隆，并用于确定该新亚基的mRNA和氨基酸序列。发现一个3.3千碱基的mRNA编码一个由775个氨基酸残基组成的成熟蛋白，其具有一个24个氨基酸的疏水前导序列。β5和β3蛋白序列之间有56%的同源性，这使它们成为整合素β亚基中关系最密切的。聚合酶链反应丰度分析显示，αv和β5 mRNA在七个非常不同的细胞系中都有发现，而β3 mRNA仅在其中三个细胞系中被发现，这表明这种新的整合素受体可能广泛分布。
