ATP-driven Na+ transport and Na(+)-dependent ATP synthesis in Escherichia coli grown at low delta mu H+.
In inverted subcellular vesicles of Escherichia coli grown at high delta mu H+ (neutral pH, no protonophorous uncoupler), ATP-driven Na+ transport and oxidative phosphorylation are completely inhibited by the protonophore CCCP. If E. coli was grown at low delta mu H+, i.e. at high pH or in the presence of uncoupler, some oxidative phosphorylation was observed in the vesicles even in CCCP-containing medium, and Na+ transport was actually stimulated by CCCP. The CCCP-resistant transport and phosphorylation were absent from the unc mutant lacking F0F1 ATPase. Both processes proved to be sensitive to (i) the Na+/H+ antiporter monensin, (ii) the Na+ uniporter ETH 157, (iii) the F0 inhibitors DCCD and venturicidin, and (iv) the F1 inhibitor aurovertin. The CCCP-resistant oxidative phosphorylation was stimulated by Na+ and arrested by oppositely directed delta pNa. These data are consistent with the assumption that, under appropriate growth conditions, the F0F1-type ATPase of E. coli becomes competent in transporting Na+ ions.
Avetisyan
A V
AV
Department of Bioenergetics, A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russia.
Bogachev
A V
AV
Murtasina
R A
RA
Skulachev
V P
VP
D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000096:biosynthesis / Q000502:physiology*; D001693:Biological Transport, Active / Q000502:physiology; D004024:Dicyclohexylcarbodiimide / Q000494:pharmacology; D004579:Electron Transport / Q000502:physiology; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D010085:Oxidative Phosphorylation / Q000187:drug effects; D012964:Sodium / Q000378:metabolism / Q000502:physiology*; D014475:Uncoupling Agents / Q000494:pharmacology
D014475:Uncoupling Agents; D004024:Dicyclohexylcarbodiimide; D000255:Adenosine Triphosphate; D012964:Sodium; D000251:Adenosine Triphosphatases