Electrogenic Na+ transport by Enterococcus hirae Na(+)-ATPase.
Energy-dependent generation of a membrane potential (delta psi) (-45 mV, interior negative) was observed in the F0F1, H(+)-ATPase-defective mutant of Enterococcus hirae. The generation of delta psi was found at high pH (but not at low pH), for which intracellular Na+ was required but not extracellular K+. The delta psi-generating activity was induced in cells cultured in media containing high concentrations of Na+, and was not observed in the Na(+)-ATPase mutants. These results suggest that E. hirae Na(+)-ATPase is responsible for the electrogenic sodium pump.
Kakinuma
Y
Y
Faculty of Pharmaceutical Sciences, Chiba University, Japan.
Igarashi
K
K
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D027682:Cation Transport Proteins; D016983:Enterococcus / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D017136:Ion Transport; D008564:Membrane Potentials; D009154:Mutation; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics / Q000378:metabolism
D027682:Cation Transport Proteins; D012964:Sodium; D000251:Adenosine Triphosphatases; C021838:sodium-translocating ATPase; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium