 Enzyme activity of ROCK1 is inhibited when the pleckstrin-homology and Rho-binding domains in the C-terminus independently bind to the N-terminus kinase domain.When a substrate such as GTP-bound RhoA binds to the Rho-binding region of the coiled-coil domain, the interactions between the N-terminus and the C-terminus are disrupted, thus activating the protein.Cleavage of the C-terminal inhibitory domain by caspase-3 during apoptosis can also activate the kinase.