title: Role of the Nha1 antiporter in regulating K(+) influx in Saccharomyces cerevisiae.
abstract: NHA1 encodes a K(+) (Na(+))/H(+) antiporter in the plasma membrane of Saccharomyces cerevisiae. We report that cells expressing the NHA1 gene contained less K(+) than the mutant lacking the gene when grown without K(+) limitation. They also grew better at low K(+) and showed higher affinity of transport than the nha1 strain. In agreement with the function of an electroneutral cation/H(+) antiporter, the effect was only observed at acidic pH. The improved growth and transport depended on the presence of Trk1p (the main K(+) influx system) and did not require the product of TRK2. We propose that Nha1p regulates the potassium content of the cell and, as a consequence, can affect the activity of the main K(+) influx system (Trk1p).
authors.affiliation: Laboratoire de Microbiologie et de Génétique, UPRES-A 7010 Université Louis Pasteur/CNRS, F-67083 Strasbourg, France.
authors.forename: María A
authors.initials: MA
authors.lastname: Bañuelos
authors.forename: María C
authors.initials: MC
authors.lastname: Ruiz
authors.forename: Adriana
authors.initials: A
authors.lastname: Jiménez
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Souciet
authors.forename: Serge
authors.initials: S
authors.lastname: Potier
authors.forename: José
authors.initials: J
authors.lastname: Ramos
mesh_terms: D001692:Biological Transport; D002352:Carrier Proteins / Q000235:genetics / Q000502:physiology; D027682:Cation Transport Proteins; D003470:Culture Media; D006863:Hydrogen-Ion Concentration; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D009154:Mutation; D011188:Potassium / Q000378:metabolism*; D012413:Rubidium / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D027682:Cation Transport Proteins; D003470:Culture Media; D008565:Membrane Proteins; C000631624:NHA1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D017923:Sodium-Hydrogen Exchangers; C068664:TRK1 protein, S cerevisiae; D012413:Rubidium; D011188:Potassium