Membrane biochemistry of the ouabain-resistant potassium transport system.
A 6.5-kilobase fragment of genomic DNA from mutant mouse cells under ouabain selection pressure conferred ouabain resistance when transfected into ouabain-sensitive CV1 green monkey fibroblasts. Ouabain resistance was induced in the presence of 10 microM ouabain. Amiloride (500 microM) completely blocked ouabain-insensitive 86Rb+ uptake into these cells. Plasma membranes from these cells demonstrated little sodium-dependent adenosine triphosphatase (ATPase) activity but had potassium-dependent and ouabain-resistant p-nitrophenylphosphatase activity. Like Na+,K+-ATPase this activity was vanadate- and sodium-inhibitable. Also, like the Na+,K+-ATPase, sodium inhibition of the p-nitrophenylphosphatase was reversed by 10 microM adenosine 5'-triphosphate.
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Tufts University School of Medicine, Boston, Massachusetts.
White
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Cantley
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D009597:4-Nitrophenylphosphatase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000584:Amiloride / Q000494:pharmacology*; D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism*; D002522:Chlorocebus aethiops; D004351:Drug Resistance; D005347:Fibroblasts / Q000378:metabolism; D051379:Mice; D010042:Ouabain / Q000494:pharmacology*; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism*; D012413:Rubidium / Q000378:metabolism; D012964:Sodium / Q000494:pharmacology; D014162:Transfection; D014638:Vanadates / Q000494:pharmacology
D014638:Vanadates; D010042:Ouabain; D000584:Amiloride; D000255:Adenosine Triphosphate; D012964:Sodium; D010744:Phosphoric Monoester Hydrolases; D009597:4-Nitrophenylphosphatase; D012413:Rubidium; D011188:Potassium