Myosin Light Chain Kinase (MLCK) Regulates Cell Migration in a Myosin Regulatory Light Chain Phosphorylation-independent Mechanism

Myosin II Light Chain Phosphorylation Regulates Membrane

Effects of relaxin on rat uterine myosin light chain kinase activity and myosin light chain phosphorylation.

Isometrically suspended uteri from estrogen-primed rats were stimulated with prostaglandin F2 alpha and then exposed to relaxin. Relaxin-dependent decreases in the ratio of phosphorylated to total myosin light chains (MLC) and in MLC kinase activity, measured in the presence of 0.5 mg/ml of uterine myosin and the absence and presence of Ca2+-calmodulin (CaM), were observed. The time-course and ...

Myosin light chain kinase and myosin light chain phosphatase from Dictyostelium: effects of reversible phosphorylation on myosin structure and function

We have partially purified myosin light chain kinase (MLCK) and myosin light chain phosphatase (MLCP) from Dictyostelium discoideum. MLCK was purified 4,700-fold with a yield of approximately 1 mg from 350 g of cells. The enzyme is very acidic as suggested by its tight binding to DEAE. Dictyostelium MLCK has an apparent native molecular mass on HPLC G3000SW of approximately 30,000 D. Mg2+ is re...

Myosin light-chain kinase of smooth muscle stimulates myosin ATPase activity without phosphorylating myosin light chain.

Myosin light-chain kinase (MLCK) of smooth muscle is multifunctional, being composed of N-terminal actin-binding domain, central kinase domain, and C-terminal myosin-binding domain. The kinase domain is the best characterized; this domain activates the interaction of smooth-muscle myosin with actin by phosphorylating the myosin light chain. We have recently shown that the Met-1-Pro-41 sequence ...

A subset of protein kinase C phosphorylation sites on the myosin II regulatory light chain inhibits phosphorylation by myosin light chain kinase.

Protein kinase C (PKC) phosphorylates the regulatory light chains of smooth muscle and cytoplasmic myosin II at three known sites: S1, S2, and T9 [Ikebe, M., Hartshorne, D. J., & Elzinga, M. (1987) J. Biol. Chem. 262, 9569-9573]. Phosphorylation at these sites inhibits the actomyosin ATPase and inhibits phosphorylation of S19 on the regulatory light chain by myosin light chain kinase (MLCK) [Ni...