Inactivation of bovine kidney cytosolic protamine kinase by the catalytic subunit of protein phosphatase 2A.
Incubation of highly purified preparations of the bovine kidney cytosolic protamine kinase in the presence of near homogeneous preparations of the catalytic subunit of protein phosphatase 2A (PrP2Ac) from bovine kidney resulted in time-dependent inactivation of the protamine kinase. By contrast, incubation of bovine kidney cytosolic casein kinase II with PrP2Ac had no effect on the activity of this casein kinase II. In the presence of 10 mM sodium fluoride, 10 mM inorganic orthophosphate, 1 mM pyrophosphate or 0.1 mM ATP, the inactivation of the protamine kinase by PrP2Ac was completely inhibited. Half-maximal inhibition by ATP occurred at about 20 microM. The rate of inactivation of the protamine kinase by PrP2Ac was unaffected by Mg2+, Mn2+, Ca2+, EDTA or EGTA at 1 mM. The results strongly indicate that the activity of the cytosolic protamine kinase is regulated by phosphorylation/dephosphorylation.
Damuni
Z
Z
Department of Biological Sciences, University of South Carolina, Columbia 29208.
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D047388:Casein Kinases; D002413:Cations, Divalent / Q000494:pharmacology; D002417:Cattle; D003600:Cytosol / Q000201:enzymology; D011756:Diphosphates / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D007668:Kidney / Q000201:enzymology*; D007700:Kinetics; D046911:Macromolecular Substances; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D006656:Protamine Kinase; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000302:isolation & purification / Q000378:metabolism; D054648:Protein Phosphatase 2; D012969:Sodium Fluoride / Q000494:pharmacology
D002413:Cations, Divalent; D011756:Diphosphates; D046911:Macromolecular Substances; D047428:Protein Kinase Inhibitors; D004533:Egtazic Acid; D000255:Adenosine Triphosphate; D012969:Sodium Fluoride; D004492:Edetic Acid; D011494:Protein Kinases; D047388:Casein Kinases; D006656:Protamine Kinase; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2