Rimm D L, Kebriaei P, Morrow J S
Department of Pathology, Yale University School of Medicine, New Haven, CT 06510.
Biochem Biophys Res Commun. 1994 Sep 30;203(3):1691-9. doi: 10.1006/bbrc.1994.2381.
At least three proteins (alpha, beta, and gamma catenin) comprise the cytoplasmic domain of the cadherin cell-cell adhesion complex. We have cloned and sequenced human epithelial alpha(E)-catenin and have identified two distinct transcripts, designated alpha 1- and alpha 2-. The human alpha 1(E)-catenin transcript predicts a 907 aa sequence 97% identical to mouse alpha-catenin. The second transcript, alpha 2(E)-catenin, displays a 24 amino acid insertion after codon 812, yielding a 931 amino acid protein (GenBank #L23805). Analysis by RT-PCR and Northern blotting detects one or both transcripts in epithelial and non-epithelial tissues. Southern blotting indicates that both arise from a single gene. The alternative transcription site in alpha-catenin is analogous to the splice site in vinculin that creates met alpha-vinculin, extending the homology between alpha-catenin and vinculin. These data with the reported structure of other catenin genes suggest that vinculin and alpha-catenin generate a superfamily of proteins mediating membrane-cytoskeletal associations.
至少三种蛋白质（α、β和γ连环蛋白）构成钙黏蛋白细胞间黏附复合体的胞质结构域。我们已克隆并测序了人类上皮α(E)-连环蛋白，鉴定出两种不同的转录本，分别命名为α1-和α2-。人类α1(E)-连环蛋白转录本预测的907个氨基酸序列与小鼠α-连环蛋白有97%的同源性。第二种转录本α2(E)-连环蛋白在第812密码子后有一个24个氨基酸的插入，产生一种931个氨基酸的蛋白质（基因库编号#L23805）。通过逆转录聚合酶链反应（RT-PCR）和Northern印迹分析在上皮组织和非上皮组织中检测到一种或两种转录本。Southern印迹表明两者都来自单个基因。α-连环蛋白中的可变转录位点类似于纽蛋白中产生metα-纽蛋白的剪接位点，扩展了α-连环蛋白和纽蛋白之间的同源性。这些数据以及其他连环蛋白基因的报道结构表明，纽蛋白和α-连环蛋白产生了一个介导膜-细胞骨架关联的蛋白质超家族。
