A Homolog of the <i>armadillo</i> Protein in <i>Drosophila</i> (Plakoglobin) Associated with E-Cadherin

TLDR

Catenins bind the cytoplasmic tail of E‑cadherin, and the identified sequence is homologous to mammalian plakoglobin and the Drosophila armadillo protein. The study proposes that armadillo plakoglobin links E‑cadherin to the actin cytoskeleton and that the E‑cadherin‑catenin complex transmits developmental signals. The authors determined the complementary DNA sequence of Xenopus beta catenin and generated a monoclonal antibody that cross‑reacts with the analogous protein in MDCK cells.

Abstract

Three cytoplasmic proteins, called catenins, bind to the cytoplasmic tail of the epithelial cell-cell adhesion molecule E-cadherin. The complementary DNA sequence was determined for the 92-kilodalton beta catenin of Xenopus laevis. The sequence is homologous to mammalian plakoglobin, a protein of desmosomal and zonula adherens cell junctions, and to the plakoglobin homolog in Drosophila melanogaster, the product of the segment polarity gene armadillo. A monoclonal antibody to bovine plakoglobin recognizes the analogous beta catenin in the Madin-Darby canine kidney (MDCK) cell line. Armadillo plakoglobin may link E-cadherin to the underlying actin cytoskeleton at cell-cell junctions; the E-cadherin-catenin protein complex may also participate in the transmission of developmental information.