Binds specifically to GTP-Rho. May function in a Rho pathway to limit stress fiber formation and/or increase the turnover of F-actin structures in the absence of high levels of RhoA activity (By similarity). Interacts with GTP-bound RhoA and RhoB. Interacts with both GTP- and GDP-bound RhoA. Interacts with KRT18 (By similarity). Belongs to the RHPN family.