A novel regulatory effect of myosin light chain kinase from smooth muscle on the ATP-dependent interaction between actin and myosin.
The actin-binding activity of myosin light chain kinase (MLCK) from smooth muscle was studied with special reference to the ATP-dependent interaction between actin and myosin. MLCK in the presence of calmodulin endowed sensitivity to Ca2+ on the movement of actin filaments on phosphorylated myosin from smooth muscle that was fixed on a coverslip. This regulatory effect was not attributable to the kinase activity of MLCK but could be explained by its actin-binding activity. The importance of the actin-binding activity was further substantiated by results of an experiment with Nitellopsis actin-cables in which MLCK regulated the interaction under conditions where MLCK was exclusively associated with the actin-cables.
Kohama
K
K
Department of Pharmacology, Gunma University School of Medicine, Japan.
Okagaki
T
T
Hayakawa
K
K
Lin
Y
Y
Ishikawa
R
R
Shimmen
T
T
Inoue
A
A
D000199:Actins / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002417:Cattle; D002645:Chickens; D004533:Egtazic Acid / Q000494:pharmacology; D005895:Gizzard, Avian / Q000201:enzymology; D006706:Homeostasis; D007700:Kinetics; D009130:Muscle, Smooth / Q000201:enzymology; D009132:Muscles / Q000378:metabolism; D009219:Myosin-Light-Chain Kinase / Q000378:metabolism*; D009218:Myosins / Q000378:metabolism*; D013270:Stomach / Q000201:enzymology
D000199:Actins; D004533:Egtazic Acid; D000255:Adenosine Triphosphate; D009219:Myosin-Light-Chain Kinase; D009218:Myosins; D002118:Calcium