Mediates Rho signaling to activate NF-kappa-B and may confer increased resistance to apoptosis to cells in gastric tumorigenesis. May play a novel role in the organization of septin structures (By similarity). Interacts via its C-terminal region with the TAX1BP3 PDZ domain. This interaction facilitates Rho-mediated activation of the c-Fos serum response element (SRE). Interacts with SEPT9 (By similarity). Specifically binds to GTP-bound RHOA, RHOB and RHOC and inhibits their GTPase activity. Abundantly expressed in brain and kidney. Weakly expressed in lung, testis, skeletal muscle, heart and thymus.