Phosphorylation of paramyosin.
1. Myofibrils isolated from Mercenaria mercenaria were phosphorylated by endogenous kinase. Over a range of ionic strengths only paramyosin was phosphorylated. 2. Thiophosphorylation of paramyosin caused an inhibition of steady-state actin-activated ATPase activity of the myofibrils. 3. It is proposed that the endogenous kinase is the catalytic subunit of the cAMP-dependent protein kinase. 4. The sequence around the phosphorylation site was determined. 5. The phosphorylation site probably is close to the C-terminus of the paramyosin molecule.
Watabe
S
S
Laboratory of Marine Biochemistry, Faculty of Agriculture, University of Tokyo, Japan.
Tsuchiya
T
T
Hartshorne
D J
DJ
D000818:Animals; D001665:Binding Sites; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism; D008974:Mollusca / Q000378:metabolism*; D009119:Muscle Contraction; D009218:Myosins / Q000378:metabolism; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D014335:Tropomyosin / Q000378:metabolism*
D014335:Tropomyosin; D011494:Protein Kinases; D017301:Ca(2+) Mg(2+)-ATPase; D009218:Myosins