E-cadherin-catenin complexes mediate cell-cell adhesion on the basolateral membrane of epithelial cells. The cytoplasmic tail of E-cadherin supports multiple protein interactions, including binding of β-catenin at the C terminus and of p120[sup ctn] to the juxtamembrane domain. The temporal assembly and polarized trafficking of the complex or its individual components to the basolateral membrane are not fully understood. In Madin-Darby canine kidney cells at steady state and after treatment with cycloheximide or temperature blocks, E-cadherin and β-catenin localized to the Golgi complex, but p120[sup ctn] was found only at the basolateral plasma membrane. We previously identified a dileucine sorting motif (Leu[sup 586]Leu[sup 587], termed S1) in the juxtamembrane domain of Ecadherin and now show that it is required to target full-length E-cadherin to the basolateral membrane. Removal of SI resulted in missorting of E-cadherin mutants (EcadΔS1) to the apical membrane; β-catenin was simultaneously missorted and appeared at the apical membrane, p120[sup ctn] was not mistargeted with EcadΔS1, but could be recruited to the E-cadherin-catenin complex only at the basolateral membrane. These findings help define the temporal assembly and sorting of the E-cadherin-catenin complex and show that membrane recruitment of p120[sup ctn] in polarized cells is contextual and confined to the basolateral membrane. [ABSTRACT FROM AUTHOR]