From cadherins to catenins: cytoplasmic protein interactions and regulation of cell adhesion.

Classical cadherins are complexed via their cytoplasmic domains with alpha-, beta- and gamma-catenin. This complex formation links cadherins to the actin filament network and to other transmembrane and cytoplasmic proteins. alpha-Catenin is homologous to vinculin, and beta-catenin to the product of the Drosophila gene armadillo, while gamma-catenin seems to be identical to plakoglobin. Catenins are part of a higher order protein structure that is of crucial importance for the adhesive function of cadherins. A working model of the construction and regulation of this multiprotein interaction is proposed.