RhoD is a member of the Rho gene family that interacts with protein kinases and serves as a target of activated GTPase. Rho binds GTP and plays a critical role in muscle differentiation by regulating the expression of myogenin and MEF2 genes. Furthermore, Rho is involved in endosome dynamics and reorganization of the actin cytoskeleton and plays a role in coordinating membrane transport. mDia and ROCK are downstream effectors of Rho mediating Rho action on the actin cytoskeleton; mDia produces actin filaments by nucleation and polymerization and ROCK activate myosin to cross-link them for induction of actomyosin bundles and contractility.