MRCK beta
MRCK beta (myotonic dystrophy kinase-related Cdc42-binding kinase beta), encoded by CDC42BPG, is an effector kinase of the small GTPase Cdc42. Upon Cdc42 binding through its CRIB region, MRCKβ phosphorylates myosin light chain and the regulatory myosin phosphatase subunit MYPT1, enhancing actomyosin contractility at the cell periphery. This drives cell migration, apical constriction and epithelial morphogenesis, and the kinase contributes to invasive behavior in squamous carcinoma models. Selective MRCK inhibitors are being developed to block Cdc42-driven motility in cancer and in fibrotic processes.
