RhoA–Rho-associated protein kinase signaling pathway (RhoA–ROCK signaling pathway)

The RhoA–Rho-associated protein kinase (ROCK) signaling pathway comprises the small GTPase RhoA and its major downstream effectors, ROCK1 and ROCK2, which are serine/threonine kinases[3][5]. RhoA cycles between inactive GDP-bound and active GTP-bound forms, with activation regulated by guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs)[7]. Upon activation, RhoA binds to and activates ROCK, which then phosphorylates numerous substrates involved in actin cytoskeleton reorganization, myosin contractility, cell adhesion, and cell migration[5][2]. This pathway is fundamental to cellular processes such as stress fiber and focal adhesion formation, cell polarity, and cell shape regulation[9][5][8]. The RhoA–ROCK pathway plays key roles in development, wound healing, cardiovascular and neurological function, but is also implicated in various pathological conditions including cancer progression, cardiovascular and neurodegenerative diseases, and osteoarthritis[3][4][9]. Selective inhibition of ROCK has been explored as a therapeutic intervention in these contexts, with several small molecules in clinical use or trials[3][5]. The pathway's broad involvement in numerous physiological processes raises safety considerations for systemic inhibition[5].

Other names

RhoA/ROCK pathwayRho/ROCK signaling pathwayRhoA–ROCK pathwayRho-associated coiled-coil kinase pathway

ROCK inhibitors bind to the kinase domain of ROCK1/ROCK2, inhibiting their activity and blocking phosphorylation of downstream substrates, reducing actomyosin contractility and altering cytoskeletal dynamics[3][5]. Inhibition of RhoA activation pathways (e.g., using C3 transferase or by targeting upstream RhoGEFs)[2][3].