title: The Nha1 antiporter of Saccharomyces cerevisiae mediates sodium and potassium efflux.
abstract: The NHA1 gene of Saccharomyces cerevisiae, transcribed into a 3.5 kb mRNA, encodes a protein mediating Na+ and K+ efflux through the plasma membrane that is required for alkali cation tolerance at acidic pH. Deletion of the gene in a wild-type strain resulted in higher sensitivity to both K+ and Na+ at acidic pH. Measurements of cation loss in strains carrying deleted or overexpressed alleles of NHA1 demonstrated its role in K+ and Na+ efflux. In addition, high K+ and Na+ efflux observed upon alkalinization of the cytoplasm implies a role of Nha1p in the regulation of intracellular pH. Moreover, the overexpression of ENA1 and NHA1 genes in an ena1-4 delta-nha1 delta strain showed that the Nha1 alkalication antiporter is responsible for growth on high concentrations of KCl and NaCl at acidic pH, and Ena alkali-cation ATPases are necessary at higher pH values. Both systems have a complementary action to maintain the intracellular steady-state concentration of K+ and Na+.
authors.affiliation: Laboratoire de Microbiologie et de GCnCtiqueUPRES-A 7010 UniversitC Louis Pasteu r/CN RS, F-67083 StrasbourgFrance.
authors.forename: Maria A
authors.initials: MA
authors.lastname: BaAueIos
authors.affiliation: Department of Membrane Transport, Institute of PhysiologyCzAcadSci, 142 20 Prague 4Czech Republic.
authors.forename: Hana
authors.initials: H
authors.lastname: Sychrová
authors.affiliation: Laboratoire de Microbiologie et de GCnCtiqueUPRES-A 7010 UniversitC Louis Pasteu r/CN RS, F-67083 StrasbourgFrance.
authors.forename: Claudine
authors.initials: C
authors.lastname: Bleykasten-Grosshans
authors.affiliation: Laboratoire de Microbiologie et de GCnCtiqueUPRES-A 7010 UniversitC Louis Pasteu r/CN RS, F-67083 StrasbourgFrance.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Souciet
authors.affiliation: Laboratoire de Microbiologie et de GCnCtiqueUPRES-A 7010 UniversitC Louis Pasteu r/CN RS, F-67083 StrasbourgFrance.
authors.forename: Serge
authors.initials: S
authors.lastname: Potier
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D017920:Antiporters / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D015152:Blotting, Northern; D015153:Blotting, Western; D027682:Cation Transport Proteins; D003001:Cloning, Molecular; D004361:Drug Tolerance / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics / Q000276:immunology / Q000502:physiology; D017353:Gene Deletion; D015870:Gene Expression / Q000235:genetics; D005822:Genetic Vectors; D006706:Homeostasis; D006863:Hydrogen-Ion Concentration; D017136:Ion Transport; D008565:Membrane Proteins / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D011188:Potassium / Q000378:metabolism*; D027961:Potassium-Hydrogen Antiporters; D011401:Promoter Regions, Genetic / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D012492:Salts / Q000494:pharmacology; D012964:Sodium / Q000378:metabolism*; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D000254:Sodium-Potassium-Exchanging ATPase
chemical_list: D017920:Antiporters; D027682:Cation Transport Proteins; C086375:ENA1 protein, S cerevisiae; D005656:Fungal Proteins; D008565:Membrane Proteins; C000631624:NHA1 protein, S cerevisiae; D027961:Potassium-Hydrogen Antiporters; D029701:Saccharomyces cerevisiae Proteins; D012492:Salts; D017923:Sodium-Hydrogen Exchangers; D012964:Sodium; D000251:Adenosine Triphosphatases; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium