A synthetic heptadecapeptide corresponding to part of the NH2-terminal 17 residues of chicken gizzard myosin light chain (Mr = 20,000), Ser-Ser-Lys-Thr-Thr-Lys-Arg-Pro-Gln-Arg-Ala-Thr-Ser-(P)-Asn-Val-Phe-Ser-NH2, was readily phosphorylated by the myosin light chain kinase isolated from the same tissue. The synthetic peptide was phosphorylated stoichiometrically at serine 13, the same residue ph...

All vertebrates contain two nonmuscle myosin II heavy chains, A and B, which differ in tissue expression and subcellular distributions. To understand how these distinct distributions are controlled and what role they play in cell migration, myosin IIA and IIB were examined during wound healing by bovine aortic endothelial cells. Immunofluorescence showed that myosin IIA skewed toward the front ...

All vertebrates contain two nonmuscle myosin II heavy chains, A and B, which differ in tissue expression and subcellular distributions. To understand how these distinct distributions are controlled and what role they play in cell migration, myosin IIA and IIB were examined during wound healing by bovine aortic endothelial cells. Immunofluorescence showed that myosin IIA skewed toward the front ...

To determine the intracellular source and release kinetics of myosin light chain 1 immediately following irreversible myocytic injury, we perfused rat hearts in a Langendorff apparatus under control conditions (20 minutes), or during global cellular injury produced by oxygenated, calcium-free perfusion (5 minutes), followed by reperfusion with buffer containing 2.5 mM calcium (15 minutes). Ligh...

Myosin light chain kinase from smooth muscle has been shown to be phosphorylated by cyclic AMP-dependent protein kinase, which leads to a decrease in the affinity of the kinase for Ca2+ . calmodulin and, hence, a decrease in enzymatic activity. This event has been proposed as a mechanism for the relaxation of smooth muscle in response to increased intracellular concentrations of cyclic AMP. The...

Myosin light chain kinase, which is located primarily in the soluble fraction of bovine myocardium, has been isolated and purified approximately 1200-fold with 16% yield by a three-step procedure. The approximate content of soluble myosin light chain kinase in heart is calculated to be 0.63 microM. The isolated kinase is active only as a ternary complex consisting of the kinase, calmodulin, and...

Myosin regulatory light chain (RLC) phosphorylation in skeletal and cardiac muscles modulates Ca(2+)-dependent troponin regulation of contraction. RLC is phosphorylated by a dedicated Ca(2+)-dependent myosin light chain kinase in fast skeletal muscle, where biochemical properties of RLC kinase and phosphatase converge to provide a biochemical memory for RLC phosphorylation and post-activation p...

Purified myosin light chain kinase from smooth muscle is phosphorylated by cyclic AMP-dependent protein kinase, protein kinase C, and the multifunctional calmodulin-dependent protein kinase II. Because phosphorylation in a specific site (site A) by any one of these kinases desensitizes myosin light chain kinase to activation by Ca2+/calmodulin, kinase phosphorylation could play an important rol...