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. Interacts with GTP-bound RhoA and RhoB. Interacts with both GTP- and GDP-bound RhoA. According to PubMed:12473120, it does not interact with RhoA. Interacts with KRT18. Widely expressed. Highly expressed in prostate, trachea, stomach, colon, thyroid and pancreas. Expressed at lower level in brain, spinal cord, kidney, placenta and liver. By thyrotropin (TSH). Regulated by the cAMP pathway. Belongs to the RHPN family.