MOLECULAR-CLONING REVEALS ALTERNATIVE SPLICE FORMS OF HUMAN ALPHA(E)-CATENIN

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 ident ified two distinct transcripts, designated alpha(1)- and alpha(2)-. Th e human alpha(1)(E)-catenin transcript predicts a 907 aa sequence 97% identical to mouse alpha-catenin. The second transcript, alpha(2)(E)-c atenin, displays a 24 amino acid insertion after codon 812, yielding a 931 amino acid protein (GenBank #L23805). analysis by RT-PCR and Nort hern blotting detects one or both transcripts in epithelial and non-ep ithelial tissues. Southern blotting indicates that both arise from a s ingle gene. The alternative transcription site in alpha-catenin is ana logous to the splice site in vinculin that creates meta-vinculin, exte nding the homology between alpha-catenin and vinculin. These data with the reported structure of other catenin genes suggest that vinculin a nd alpha-catenin generate a superfamily of proteins mediating membrane -cytoskeletal associations. (C) 1994 Academic Press, Inc.