Recruitment of E-cadherin associated with alpha- and beta-catenins and p120ctn to the nectin-based cell-cell adhesion sites by the action of 12-O-tetradecanoylphorbol-13-acetate in MDCK cells.

The formation of tight junctions (TJs) is dependent on the formation of adherens junctions (AJs) in MDCK cells. E-Cadherin and nectin are major cell-cell adhesion molecules (CAMs) at AJs, whereas claudin, occludin and junctional adhesion molecule (JAM) are major CAMs at TJs. When MDCK cells precultured at 2 microm Ca(2+) are cultured at 2 mm Ca(2+), nectin first forms cell-cell adhesion and recruits E-cadherin to the nectin-based cell-cell adhesion sites to form AJs. Thereafter, nectin recruits first JAM-A and then claudin-1 and occludin to the apical side of AJs to form TJs. In contrast, when MDCK cells precultured at 2 microm Ca(2+) are cultured at 2 microm Ca(2+) in the presence of a phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA), a TJ-like structure is formed without the formation of the E-cadherin-based AJs. We showed here that GFP-E-cadherin, which did not trans-interact due to 2 microm Ca(2+) but associated with alpha- and beta-catenins and p120(ctn), was recruited to the nectin-based cell-cell adhesion sites by the action of TPA. The nectin inhibitors, which inhibited the trans-interaction of nectin, inhibited the recruitment of GFP-E-cadherin and their associating catenins by the action of TPA. Microbeads coated with the extracellular fragment of nectin recruited not only cellular nectin but also GFP-E-cadherin and their associating catenins by the action of TPA. These results indicate that when the TJ-like structure is formed by the action of TPA, non-trans-interacting E-cadherin and its associating catenins are recruited to the nectin-based cell-cell adhesion sites and that the trans-interaction of E-cadherin is not essential for the formation of TJs.