期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2010
卷号：107
期号：33
页码：14591-14596
DOI：10.1073/pnas.1007349107
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The ternary complex of cadherin, {beta}-catenin, and {alpha}-catenin regulates actin-dependent cell-cell adhesion. {alpha}-Catenin can bind {beta}-catenin and F-actin, but in mammals {alpha}-catenin either binds {beta}-catenin as a monomer or F-actin as a homodimer. It is not known if this conformational regulation of {alpha}-catenin is evolutionarily conserved. The Caenorhabditis elegans {alpha}-catenin homolog HMP-1 is essential for actin-dependent epidermal enclosure and embryo elongation. Here we show that HMP-1 is a monomer with a functional C-terminal F-actin binding domain. However, neither full-length HMP-1 nor a ternary complex of HMP-1-HMP-2({beta}-catenin)-HMR-1(cadherin) bind F-actin in vitro, suggesting that HMP-1 is auto-inhibited. Truncation of either the F-actin or HMP-2 binding domain of HMP-1 disrupts C. elegans development, indicating that HMP-1 must be able to bind F-actin and HMP-2 to function in vivo. Our study defines evolutionarily conserved properties of {alpha}-catenin and suggests that multiple mechanisms regulate {alpha}-catenin binding to F-actin.
