Identification of a calmodulin-dependent glycogen synthase kinase in rabbit skeletal muscle, distinct from phosphorylase kinase.
A glycogen synthase kinase that is completely dependent on Ca2+ and calmodulin has been identified in mammalian skeletal muscle, and purified approximately 3000-fold by chromatography on phosphocellulose and calmodulin--Sepharose. The presence of 50 mM NaCl in the homogenisation buffer was critical for extraction of the enzyme. The calmodulin-dependent glycogen synthase kinase (app. Mr 850 000) is distinct from myosin light-chain kinase and phosphorylase kinase, but phosphorylates the same serine residue on glycogen synthase as phosphorylase kinase. The physiological role of the enzyme is discussed.
D000818:Animals; D002118:Calcium / Q000502:physiology; D002135:Calcium-Binding Proteins / Q000502:physiology*; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D002147:Calmodulin / Q000502:physiology*; D000242:Cyclic AMP / Q000378:metabolism; D038341:Glycogen Synthase Kinases; D009132:Muscles / Q000201:enzymology*; D009218:Myosins / Q000378:metabolism; D010764:Phosphorylase Kinase / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D011817:Rabbits; D012694:Serine / Q000378:metabolism
D002135:Calcium-Binding Proteins; D002147:Calmodulin; D012694:Serine; D000242:Cyclic AMP; D011494:Protein Kinases; D010764:Phosphorylase Kinase; D038341:Glycogen Synthase Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D009218:Myosins; D002118:Calcium