Inactive GDP-bound Rho GTPases reside in the cytosol, are found in a complex with Rho GDP-dissociation inhibitors (Rho GDIs), and are released from the GDI protein in order to translocate to membranes upon activation (By similarity). May be involved in cell polarity control during the actin-dependent tip growth of pollen tubes. Associated with the membrane when activated. Expressed at the tip of pollen tubes. Belongs to the small GTPase superfamily. Rho family.