Rho-associated protein kinase 1 and 2 (ROCK1/ROCK2)

Rho-associated protein kinase 1 (ROCK1) and Rho-associated protein kinase 2 (ROCK2) are serine/threonine kinases that serve as primary downstream effectors of the small GTPase RhoA [1, 2]. They are central regulators of the actin cytoskeleton, governing essential cellular processes such as contraction, motility, adhesion, and morphology [2, 15]. While they share significant structural homology, particularly in their kinase domains, they exhibit distinct tissue distributions and non-redundant roles; ROCK1 is widely expressed and notably involved in apoptosis-induced membrane blebbing, whereas ROCK2 is enriched in the brain and heart and plays a key role in smooth muscle calcium sensitivity [1, 10]. Dysregulation of ROCK signaling is implicated in numerous pathologies, including cardiovascular diseases like hypertension, ocular conditions such as glaucoma, and various fibrotic and neurodegenerative disorders [3, 6]. Therapeutic strategies involve the use of small-molecule inhibitors that compete with ATP for binding to the kinase domain, leading to reduced phosphorylation of substrates like myosin light chain [6, 9]. Clinically approved ROCK inhibitors include fasudil for cerebral vasospasm, netarsudil for glaucoma, and the ROCK2-selective inhibitor belumosudil for chronic graft-versus-host disease [6, 8].

Other names

Rho-associated, coiled-coil-containing protein kinase 1Rho-associated, coiled-coil-containing protein kinase 2ROCK1ROCK2p160ROCKp164ROCKROKbetaROKalpha

ATP-competitive inhibition of the kinase domain, which prevents the phosphorylation of downstream substrates such as myosin light chain (MLC), myosin phosphatase targeting subunit 1 (MYPT1), and LIM kinase (LIMK), thereby modulating actomyosin contractility and cytoskeletal dynamics.