Direct Interaction of 14-3-3ζ with Ezrin Promotes Cell Migration by Regulating the Formation of Membrane Ruffle

14-3-3 proteins have been shown to regulate the actin cytoskeleton remodeling, cell adhesion and migration. In this study, we identified ezrin, a cross-linker between plasma membrane and actin cytoskeleton, as a novel 14-3-3 zeta interacting partner. The direct interaction between 14-3-3 zeta and ezrin was validated in the cells and by in vitro assays. We showed that the 14-3-3 zeta binding region in ezrin was located within the N-terminal and central alpha-helical domains and that the alpha G-to-alpha l helices of 14-3-3 zeta are responsible for the binding to ezrin. Functional analyses revealed that the regulation of cell migration and membrane ruffling by 14-3-3 zeta is ezrin dependent, for which the integrity of ezrin protein was required. Conversely, the knockdown of 14-3-3 zeta abrogates also the stimulatory effect of ezrin on cell migration and membrane ruffling. Moreover, we found that the phosphorylation of Thr567 in ezrin facilitates the 14-3-3 zeta ezrin interaction and the formation of membrane ruffles. Taken together, these results suggest strongly that the functions of these two proteins in cell migration are linked and might be mediated by their direct physical interaction, which is important for the formation of membrane ruffles. (C) 2014 Elsevier Ltd. All rights reserved.