Fig. 6. Model depicting the role of RhoA in regulating actin cytoskeleton organization in vasopressin-stimulated renal cells. Vasopressin raises intracellular cAMP with consequent activation of PKA, which phosphorylates AQP2 and RhoA. Rho phosphorylation causes a decrease in the binding to its putative effectors, the Rho kinases. The attenuation of Rho activity results in depolymerization of F-actin, facilitating AQP2 insertion into the plasma membrane.