ROCK1 A gene on chromosome 18q11.1 that encodes a protein kinase, which is a key regulator of actin cytoskeleton and cell polarity. It regulates smooth muscle contraction, actin cytoskeleton organisation, stress-fibre and focal adhesion formation, and neurite retraction, as well as cell adhesion and motility via phosphorylation of DAPK3, GFAP, LIMK1, LIMK2, MYL9/MLC2, PFN1 and PPP1R12A. It phosphorylates FHOD1, and both promote SRC-dependent non-apoptotic plasma membrane blebbing. ROCK1 also: phosphorylates JIP3 and regulates JNK to JIP3 recruitment in response to UVB-induced stress; suppresses inflammatory cell migration by regulating PTEN phosphorylation and stability; downregulates VEGF-induced angiogenic endothelial cell activation; promotes keratinocyte terminal differentiation; and plays a role in terminal erythroid differentiation. ROCK1 is required for centrosome positioning and centrosome-dependent exit from mitosis. It may regulate closure of the eyelids and ventral body wall by inducing the assembly of actomyosin bundles.