Wnt3A Induces GSK-3β Phosphorylation and β-Catenin Accumulation Through RhoA/ROCK

In canonical pathway, Wnt3A has been known to stabilize beta-catenin through the dissociation between beta-catenin and glycogen synthase kinase-3 beta (GSK-3 beta) that suppresses the phosphorylation and degradation of beta-catenin. In non-canonical signaling pathway, Wnt was known to activate Rho GTPases and to induce cell migration. The cross-talk between canonical and non-canonical pathways by Wnt signaling; however, has not been fully elucidated. Here, we revealed that Wnt3A induces not only the phosphorylation of GSK-3 beta and accumulation of beta-catenin but also RhoA activation in RAW264.7 and HEK293 cells. Notably, sh-RhoA and Tat-C3 abolished both the phosphorylation of GSK-3 beta and accumulation of beta-catenin. Y27632, an inhibitor of Rho-associated coiled coil kinase (ROCK) and siROCK inhibited both GSK-3 beta phosphorylation and beta-catenin accumulation. Furthermore, active domain of ROCK directly phosphorylated the purified recombinant GSK-3 beta in vitro. In addition, Wnt3A-induced cell proliferation and migration, which were inhibited by Tat-C3 and Y27632. Taken together, we propose the cross-talk between canonical and non-canonical signaling pathways of Wnt3A, which induces GSK-3 beta phosphorylation and beta-catenin accumulation through RhoA and ROCK activation. (C) 2016 Wiley Periodicals, Inc.