EPHB receptor-induced phosphorylation of coffin is at least partially controlled by Rho-associated kinase (ROCK) and LIM domain kinase (LIMK) activities (Shi et al. 2009). ROCK structure comprises a kinase domain located at the amino terminus of the protein, a coiled-coil region containing the Rho-binding domain (RBD), and a pleckstrin-homology (PH) domain with a cysteine-rich domain (CRD). In resting cells ROCKs exist in an autoinhibition state where the kinase domain interacts with the C-terminal inhibitory region. Binding of active RHOA:GTP to RBD stimulates the phosphotransferase activity of ROCK by disrupting the interaction between the catalytic and the inhibitory C-terminal region of the enzyme (Khalil 2010).