National Center for
4K1N: Crystal structure of full-length mouse alphaE-catenin
An autoinhibited structure of alpha-catenin and its implications for vinculin recruitment to adherens junctions
J. Biol. Chem. (2013) 288 p.15913-15925
alpha-Catenin is an actin- and vinculin-binding protein that regulates cell-cell adhesion by interacting with cadherin adhesion receptors through beta-catenin, but the mechanisms by which it anchors the cadherin-catenin complex to the actin cytoskeleton at adherens junctions remain unclear. Here we determined crystal structures of alphaE-catenin in the autoinhibited state and the actin-binding domain of alphaN-catenin. Together with the small-angle x-ray scattering analysis of full-length alphaN-catenin, we deduced an elongated multidomain assembly of monomeric alpha-catenin that structurally and functionally couples the vinculin- and actin-binding mechanisms. Cellular and biochemical studies of alphaE- and alphaN-catenins show that alphaE-catenin recruits vinculin to adherens junctions more effectively than alphaN-catenin, partly because of its higher affinity for actin filaments. We propose a molecular switch mechanism involving multistate conformational changes of alpha-catenin. This would be driven by actomyosin-generated tension to dynamically regulate the vinculin-assisted linkage between adherens junctions and the actin cytoskeleton.