Protein kinase C-related kinase homology region 1 (HR1) Rho-binding domain of Rhophilin
Rhophilins are scaffolding proteins that function as effectors of the Rho family of small GTPases. Vertebrates harbor two proteins, Rhophilin-1 and Rhophilin-2, whose exact functions are yet to be determined. Rhophilin-1 has been implicated in sperm motility. Rhophilin-2 regulates the organization of the actin cytoskeleton. Rhophilins contain N-terminal HR1, central Bro1-like, and C-terminal PDZ domains; all are protein-interacting domains. HR1 domains are anti-parallel coiled-coil (ACC) domains that bind small GTPases from the Rho family; both Rhophilin-1 and Rhophilin-2 bind RhoA, and Rhophilin-2 has also been shown to bind RhoB.
Jiyao W et al.(2023). "The conserved domain database in 2023.",