Cloning, primary structure and properties of a novel human integrin beta subunit.
Cloning, primary structure and properties of a novel human integrin beta subunit.
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新型人类整合素β亚基的克隆、一级结构和特性。
DOI：
10.1002/j.1460-2075.1990.tb08275.x
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Hemler,ME
中科院分区：
文献类型：
--
作者：
Ramaswamy,H;Hemler,ME
最早描述的定义整合素异二聚体三个亚家族的整合素β亚基是β1、β2和β3。在本文中，我们描述了一个新的人整合素β亚基的编码区的分离，命名为β5。该基因编码799(或796)个氨基酸，包括一个23个氨基酸的前导序列。成熟蛋白含有776个(或773个)氨基酸，包括696个氨基酸的胞外区、57个氨基酸的跨膜区和胞内C-末端结构域。β5序列与已知的β3、β1和β2序列的相似性分别为55%、43%和38%，包括56/56个半胱氨酸的保守性。兔抗血清是针对根据β5 C末端序列预测的20个氨基酸的合成肽而制备的。此血清免疫沉淀的β5蛋白为100,000 mR(减少)和95,000 mR(未减少)。只检测到一个与β5相关的阿尔法亚基，该阿尔法亚基在免疫化学上与先前发现的作为玻璃体连接素受体复合体一部分的阿尔法v亚基无法区分。免疫沉淀法显示，β5在肿瘤细胞系中最常见，在肝癌和成纤维细胞系中也存在，在淋巴母细胞和血小板中不存在。
The originally described integrin beta subunits that define the three subfamilies of integrin heterodimers are beta 1, beta 2 and beta 3. In this paper, we describe the isolation of a cDNA coding for a novel human integrin beta subunit, designated as beta 5. The beta 5 cDNA was isolated from a human thymic epithelial cell library, using oligonucleotide probes that were designed from a region highly conserved among the known beta 1, beta 2 and beta 3 sequences. The beta 5 cDNA codes for 799 (or 796) amino acids, including a 23 amino acid leader sequence. There are 776 (or 773) amino acids in the mature protein, which includes a long extracellular domain of 696 amino acids, a transmembrane domain and an intracellular C‐terminal domain of 57 amino acids. The beta 5 sequence resembled the known beta 3, beta 1 and beta 2 sequences by 55, 43 and 38%, respectively, including conservation of 56/56 cysteines. Rabbit antiserum was prepared against a 20 amino acid synthetic peptide predicted from the beta 5 C‐terminal sequence. This serum immunoprecipitated a beta 5 protein that was 100,000 Mr (reduced) and 95,000 Mr (nonreduced). Only a single alpha subunit was detected in association with beta 5, and that alpha subunit was immunochemically indistinguishable from the alpha v subunit previously found as part of the vitronectin receptor complex. By immunoprecipitation, beta 5 was most prevalent on carcinoma cell lines, was also present on hepatoma and fibroblast cell lines, and was absent from lymphoblastoid cells and platelets.