Involvement of the annexin II-S100A10 complex in the formation of E-cadherin-based adherens junctions in madin-darby canine kidney cells

Abstract

E-cadhetin and nectins are major cell-cell adhesion molecules at adherens junctions (AJs) in epithelial cells. When Madin-Darby canine kidney (MDCK) cells stably expressing nectin-1 (nectin-1-MDCK cells) are cultured at normal Ca 2+, E-cadherin and nectin-1 are concentrated at the cell-cell contact sites. When these cells are cultured at low Ca2+, E-cadherin disappears from the cell-cell contact sites, but nectin-1 persists there. When these cells are re-cultured at normal Ca2+, E-cadherin is recruited to the nectin-based cell-cell contact sites. We found here that this recruitment was dependent on protein synthesis, because a protein synthesis inhibitor, cycloheximide, prevented the accumulation of E-cadherin. When nectin-1-MDCK cells, precultured at low Ca2+ in the presence of a proteasome inhibitor, ALLN (N-acetyl-Leu-Leu-norleucinal), were re-cultured at normal Ca2+, E-cadherin was recruited to the nectin-based cell-cell contact sites but the level of E-cadherin was reduced. Similar results were obtained when wild-type MDCK cells were used instead of nectin-1-MDCK cells. These results suggest that degradation of one or more protein factors and de novo synthesis of the same or different protein factor(s) are needed for the formation of the E-eadherin-based AJs. We biochemically identified the annexin II-S100A10 complex as such a candidate. Depletion of plasma membrane cholesterol, which abolished the localization of the annexin II-S100A10 complex at the plasma membrane, inhibited the re-concentration of E-cadherin at the Bectin-based cell-cell contact sites in the Ca2+ switch experiment. Knockdown of annexin II by RNA interference also inhibited the re-concentration of E-cadherin. These results indicate that the annexin II-S100A10 complex is involved in the formation of the E-cadherin-based AJs in MDCK cells.