δ-catenin affects the localization and stability of p120-catenin by competitively interacting with E-cadherin

E-cadherin is a member of the cadherin family of Ca2+-dependent cell-cell adhesion molecules. p120-Catenin and delta-catenin are known to bind to similar juxtamembrane regions of E-cadherin, and p120-catenin is known to stabilize E-cadherin. However, the function of competition between p120-catenin and delta-catenin for E-cadherin has not been fully explained. In this report, we show that cells overexpressing delta-catenin contain less p120-catenin than control cells at the cell-cell interface and that this causes the relocalization of p120-catenin from the plasma membrane to the cytosol. We show that successful binding by one to E-cadherin adversely affects the stability of the other.