title: Transmembrane gradient of K+ ions as an energy source in the yeast Saccharomyces carlsbergensis.
abstract: In the presence of 100 mM glucose antimycin A inhibits the respiration of the yeast S. carlsbergensis by 94%, but does not affect the K+ efflux, Mn2+ influx or the synthesis of high molecular weight polyphosphate (HPP). Therefore phosphorylation at the respiratory chain level is not involved in HPP synthesis or Mn2+ accumulation. Zn2+ similar to Mn2+ induces K+ efflux and HPP synthesis, while Co2+ and Ni2+ fail to produce these effects. The extracellular K+ (1-5 mM KCl) completely inhibits the HPP synthesis and reduces Mn2+ uptake by 40%. NaCl (60 mM) inhibits the HPP synthesis by 28%. Nigericin, candicidin and FCCP plus valinomycin completely prevent the HPP synthesis. The prolonged accumulation of Zn2+ and Mn2+ is accompanied by HPP conversion into low molecular weight polyphosphate (LPP). The HPP synthesis in response to the K+ efflux may be regarded as a specific regulatory mechanism, which increases the energy efficiency of yeast metabolism.
mesh_terms: D000968:Antimycin A / Q000494:pharmacology; D001693:Biological Transport, Active / Q000187:drug effects; D002412:Cations; D002462:Cell Membrane / Q000378:metabolism; D004734:Energy Metabolism; D008345:Manganese / Q000494:pharmacology; D008970:Molecular Weight; D011122:Polyphosphates / Q000096:biosynthesis; D011188:Potassium / Q000378:metabolism*; D012440:Saccharomyces / Q000378:metabolism*; D015032:Zinc / Q000494:pharmacology
chemical_list: D002412:Cations; D011122:Polyphosphates; D008345:Manganese; D000968:Antimycin A; D015032:Zinc; D011188:Potassium