The Cadherin-11 Cytoplasmic Juxtamembrane Domain Promotes α-Catenin Turnover at Adherens Junctions and Intercellular Motility

Abstract

Cadherins mediate homophilic cell adhesion and contribute to tissue morphogenesis and architecture. Cadherin cell adhesion contacts are actively remodeled and impact cell movement and migration over other cells. We found that expression of a mutant cadherin-11 lacking the cytoplasmic juxtamembrane domain (JMD) diminished the turnover of α-catenin at adherens junctions as measured by fluorescence recovery after photobleaching. This resulted in markedly diminished cell intercalation into monolayers reflecting reduced cadherin-11-dependent cell motility on other cells. Furthermore, the actin cytoskeleton in cadherin-11 ΔJMD cells revealed a more extensive cortical F-actin ring that correlated with significantly higher levels of activated Rac1. Together, these data implicate the cadherin-11 cytoplasmic JMD as a regulator of α-catenin turnover at adherens junctions and actin-cytoskeletal organization that is critical for intercellular motility and rearrangement in multicellular clusters.