GTP gamma S-induced phosphorylation of myosin light chain kinase in smooth muscle.
Phosphorylation of myosin light chain kinase by a Ca(2+)-dependent protein kinase increases the concentration of Ca2+/calmodulin required for half-maximal activation. The Ca2+ concentrations required for myosin light chain kinase phosphorylation in permeable smooth muscle are similar to those required for myosin light chain phosphorylation. Both GTP gamma S and carbachol increase the Ca2+ sensitivity of myosin light chain kinase phosphorylation as well as light chain phosphorylation. It is proposed that a similar G-protein mediated mechanism regulates the Ca(2+)-dependent phosphorylation of these two contractile proteins in smooth muscle.
Department of Physiology, University of Texas Southwestern Medical Center at Dallas 75235-9040.
D C
DC
Tang
Y
Y
Kubota
K E
KE
Kamm
J T
JT
Stull
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002217:Carbachol / Q000494:pharmacology; D002417:Cattle; D002463:Cell Membrane Permeability; D004928:Escin / Q000494:pharmacology; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology*; D066298:In Vitro Techniques; D009130:Muscle, Smooth / Q000378:metabolism*; D009219:Myosin-Light-Chain Kinase / Q000378:metabolism*; D009218:Myosins / Q000378:metabolism; D010766:Phosphorylation
D016244:Guanosine 5'-O-(3-Thiotriphosphate); D004928:Escin; D002217:Carbachol; D009219:Myosin-Light-Chain Kinase; D009218:Myosins; D002118:Calcium