Down-Regulation of Myosin Light Chain Kinase Expression in Vascular Smooth Muscle Cells Accelerates Cell Proliferation: Requirement of Its Actin-binding Domain for Reversion to Normal Rates

• Main Authors: Hong Hui Wang, Akio Nakamura, Shinji Yoshiyama, Ryoki Ishikawa, Na Cai, Li-Hong Ye, Hiromi Takano-Ohmuro, Kazuhiro Kohama
• Format: Article
• Language: English
• Published: Elsevier 2012-01-01
• Series: Journal of Pharmacological Sciences
• Online Access: http://www.sciencedirect.com/science/article/pii/S1347861319305274

Myosin light-chain kinase (MLCK) is a multi-domain protein with kinase and actin-binding domains, among others. Deficiency of MLCK expression in GBaSM-4 vascular smooth muscle cells enhanced cell proliferation rate and shortened cell doubling time. Transient transfection of the MLCK-deficient cells with cDNA constructs of either wild-type MLCK or its mutant lacking the kinase activity reverted the cell proliferation rate to that of wild-type cells, whereas that of MLCK lacking the actin-binding domain maintained cell proliferation at an elevated rate similar to the MLCK-deficient cells. Thus, the actin-binding domain of MLCK seems to play a role in regulating cell proliferation. Keywords:: myosin light-chain kinase, actin-binding domain, vascular smooth muscle proliferation