Functional regulation of reconstituted Na,K-ATPase by protein kinase A phosphorylation.
Reconstituted Na+,K+-ATPase from either pig kidney or shark rectal glands was phosphorylated by cAMP dependent protein kinase, PKA. The stoichiometry was approximately 0.9 mol P(i)/mol alpha-subunit in the pig kidney enzyme and approximately 0.2 mol P(i)/mol alpha-subunit in the shark enzyme. In shark, Na+,K+-ATPase PKA phosphorylation increased the maximum hydrolytic activity for cytoplasmic Na+ activation and extracellular K+ activation without affecting the apparent K(m) values. In contrast, no significant functional effect after PKA phosphorylation was observed in pig kidney Na+,K+-ATPase.
Cornelius
F
F
Department of Biophysics, University of Aarhus, Denmark.
Logvinenko
N
N
D000818:Animals; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D004789:Enzyme Activation; D006868:Hydrolysis; D007668:Kidney / Q000201:enzymology; D017830:Octoxynol / Q000494:pharmacology; D010766:Phosphorylation; D011188:Potassium / Q000494:pharmacology; D012491:Salt Gland / Q000201:enzymology; D012754:Sharks; D012964:Sodium / Q000494:pharmacology; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D013552:Swine
D017830:Octoxynol; D012964:Sodium; D017868:Cyclic AMP-Dependent Protein Kinases; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium