Specific Conserved C-terminal Amino Acids of Caenorhabditis elegans HMP-1/-Catenin Modulate F-actin Binding

Background: -Catenin is a crucial link between adherens junctions and F-actin. Results:C-terminal amino acids inHMP-1/-catenin quantitativelymodulate its ability to bind F-actin, but a putative vinculin-binding domain is not required in vivo. Conclusion: Key C-terminal residues in -catenin modulate its ability to bind F-actin. Significance: This is the first genetic dissection of the ability of -catenin to bind F-actin. Stable intercellular adhesions formed through the cadherin-catenin complex are important determinants of proper tissue architecture and help maintain tissue integrity during morpho-genetic movements in developing embryos. A key regulator of this stability is -catenin, which connects the cadherin-catenin complex to the actin cytoskeleton. Although the C-terminal F-actin-binding domain of -catenin has been shown to be cru-cial for its function, a more detailed in vivo analysis of discrete regions and residues required for actin binding has not been performed. UsingCaenorhabditis elegans as amodel system, w