Myosin light chain kinase, smooth muscle (MLCK)

Myosin light chain kinase, smooth muscle (commonly abbreviated as MLCK or MYLK1), is a serine/threonine-specific protein kinase that phosphorylates the regulatory light chain of myosin II in smooth muscle cells, activating actin-myosin interaction and initiating muscle contraction[1][3][4][8]. Smooth muscle MLCK contains distinct domains for actin and myosin binding, and its activity is tightly regulated by calcium/calmodulin binding. It is central to the regulation of smooth muscle tone in vascular, gastrointestinal, urinary, and other organ systems, and is multifaceted in its control of cell shape, motility, and contractility[1][3][2][4][8]. MLCK dysfunction or pharmacological modulation has significant physiological and pathophysiological consequences, making it a critical therapeutic target for disorders of smooth muscle contractility and, potentially, other chronic disease states.

Other names

Myosin light-chain kinase (MLCK)MYLK1 (gene name for smooth muscle isoform)Smooth muscle myosin light chain kinase (smMLCK)20-kDa myosin light chain kinase (MLC20 kinase)Telokin (alternative product encoded by MYLK1)

Inhibition of MLCK kinase activity, reducing phosphorylation of myosin regulatory light chain and thus inducing smooth muscle relaxation. Inhibition may also influence cell migration and barrier permeability.