A novel P-type Cl(-)-stimulated ATPase: phosphorylation and specificity.
Utilizing a proteoliposomal preparation containing Cl(-)-ATPase, it was demonstrated that [gamma-32P]ATP-induced phosphorylation of this pump is by way of a relatively low binding affinity while protein dephosphorylation was accelerated by increasing concentrations of unlabeled ATP. Ca2+ and Mn2+ were also shown to stimulate phosphorylation of the enzyme, but to a much lesser extent than Mg2+. Orthovanadate inhibition of enzyme phosphorylation was directly related to its concentration. These results suggested that the Cl(-)-pump was a P-type ATPase similar to that found in plants and fungi based upon its low-affinity phosphorylation kinetics.
Gerencser
G A
GA
Department of Physiology, College of Medicine, University of Florida, Gainesville 32610.
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D027321:Anion Transport Proteins; D001048:Aplysia / Q000201:enzymology*; D002118:Calcium / Q000494:pharmacology; D002413:Cations, Divalent / Q000494:pharmacology; D007700:Kinetics; D008081:Liposomes / Q000378:metabolism; D008274:Magnesium / Q000494:pharmacology; D008345:Manganese / Q000494:pharmacology; D010750:Phosphoproteins / Q000302:isolation & purification / Q000378:metabolism*; D011510:Proteolipids / Q000378:metabolism; D014638:Vanadates / Q000494:pharmacology
D027321:Anion Transport Proteins; D002413:Cations, Divalent; D008081:Liposomes; D010750:Phosphoproteins; D011510:Proteolipids; C020485:proteoliposomes; D014638:Vanadates; D008345:Manganese; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; C031652:anion-sensitive ATPases; D008274:Magnesium; D002118:Calcium