Reevaluating ?E-catenin monomer and homodimer functions by characterizing E-cadherin/?E-catenin chimeras.

ABSTRACT: As part of the E-cadherin-?-catenin-?E-catenin complex (CCC), mammalian ?E-catenin binds F-actin weakly in the absence of force, whereas cytosolic ?E-catenin forms a homodimer that interacts more strongly with F-actin. It has been concluded that cytosolic ?E-catenin homodimer is not important for intercellular adhesion because E-cadherin/?E-catenin chimeras thought to mimic the CCC are sufficient to induce cell-cell adhesion. We show that, unlike ?E-catenin in the CCC, these chimeras homodimerize, bind F-actin strongly, and inhibit the Arp2/3 complex, all of which are properties of the ?E-catenin homodimer. To more accurately mimic the junctional CCC, we designed a constitutively monomeric chimera, and show that E-cadherin-dependent cell adhesion is weaker in cells expressing this chimera compared with cells in which ?E-catenin homodimers are present. Our results demonstrate that E-cadherin/?E-catenin chimeras used previously do not mimic ?E-catenin in the native CCC, and imply that both CCC-bound monomer and cytosolic homodimer ?E-catenin are required for strong cell-cell adhesion.

SUBMITTER: Bianchini JM 

PROVIDER: S-EPMC4586751 | biostudies-literature | 2015 Sep

REPOSITORIES: biostudies-literature