4k1n
From Proteopedia
Crystal structure of full-length mouse alphaE-catenin
Structural highlights
FunctionCTNA1_MOUSE Associates with the cytoplasmic domain of a variety of cadherins. The association of catenins to cadherins produces a complex which is linked to the actin filament network, and which seems to be of primary importance for cadherins cell-adhesion properties. Can associate with both E- and N-cadherins. Originally believed to be a stable component of E-cadherin/catenin adhesion complexes and to mediate the linkage of cadherins to the actin cytoskeleton at adherens junctions. In contrast, cortical actin was found to be much more dynamic than E-cadherin/catenin complexes and CTNNA1 was shown not to bind to F-actin when assembled in the complex suggesting a different linkage between actin and adherens junctions components. The homodimeric form may regulate actin filament assembly and inhibit actin branching by competing with the Arp2/3 complex for binding to actin filaments. May play a crucial role in cell differentiation.[1] Publication Abstract from PubMedalpha-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 owing to its higher affinity for actin filaments. We propose a molecular switch mechanism involving multi-state 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. An Autoinhibited Structure of alpha-catenin and Its Implications for Vinculin Recruitment to Adherens Junctions.,Ishiyama N, Tanaka N, Abe K, Yang YJ, Abbas YM, Umitsu M, Nagar B, Bueler SA, Rubinstein JL, Takeichi M, Ikura M J Biol Chem. 2013 Apr 15. PMID:23589308[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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