Activated RHOA (RHOA:GTP) binds rhophilin-1 (RHPN1) or rophilin-2 (RHPN2). RHPN1 and RHPN2 share 75% sequence identity, with the RHO-binding domain at the N-terminus, followed by the BRO1 domain in their central region (characteristic of proteins involved in protein kinase C signaling), and the PDZ domain in the C-terminal region. PDZ domains of RHPN1 and RHPN2 exhibit little homology (Watanabe et al. 1996, Peck et al. 2002). RHPN2 may be involved in the regulation of the actin cytoskeleton organization downstream of RHOA (Peck et al. 2002).