Catenins as mediators of the cytoplasmic functions of cadherins

Abstract

SUMMARY The catenins are polypeptides that bind to the conserved cytoplasmic tail of cadherins and are required for cadherin function. α-Catenin is related to vinculin and seems to be required for the interaction of cadherins with the actin cytoskeleton. β-Catenin is homologous to armadillo, a segment polarity gene in Drosophila that participates in developmental signaling. Recent findings indicate that β-catenin also participates in developmental signaling and embryonic patterning in Xenopus laevis. At least a portion of the electrophoretic band migrating at the position of γ-catenin consists of plakoglobin, a desmosomal and zonula adherens protein that has high sequence similarity to β-catenin and armadillo. The catenins may be involved in the regulation of cadherin function during tissue morphogenesis and tumorigenesis.