ARF6-GTP recruits Nm23-H1 to facilitate dynamin-mediated endocytosis during adherens junctions disassembly

ARF6-regulated endocytosis of E-cadherin is essential during the disassembly of adherens junctions in epithelial cells. Here, we show that activation of ARF6 promotes clathrin-dependent internalization of E-cadherin and caveolae at the basolateral cell surface. Furthermore, we demonstrate that ARF6-GTP, a constitutively activate form of ARF6, interacts with and recruits Nm23-H1, a nucleoside diphosphate (NDP) kinase that provides a source of GTP for dynamin-dependent fission of coated vesicles during endocytosis. Finally, we show that ARF6-mediated recruitment of Nm-23-H1 to cell junctions is accompanied by a decrease in the cellular levels of Rac1-GTP, consistent with previous findings that Nm23-H1 down-regulates activation of Rac1. These studies provide a molecular basis for ARF6 function in polarized epithelia during adherens junction disassembly.