Myosin light chain kinase (MLCK) is a serine/threonine kinase that belongs to CaM Kinases (Ca++/Calmodulin-dependent protein kinases) family. MLCK is involved in the regulation of myosin activity during smooth muscle contraction. At increased level of Ca2+, rapid binding of Ca2+ to Calmodulin (CaM) occurs, triggering MLCK activation. Once activated, MLCK phosphorylates myosin light chain (MLC) and leading to cross-bridges cycling and generation of the contractile force (1). MLCK has been implicated in the regulation of endothelial and vascular permeability and in signaling pathway which leads to fibroblast apoptosis (2).
