title: A physiological, biochemical and proteomic characterization of Saccharomyces cerevisiae trk1,2 transport mutants grown under limiting potassium conditions.
abstract: Saccharomyces cerevisiae mutants lacking both isoforms of the main plasma membrane potassium transporter display impaired potassium transport and defective growth at limiting concentrations of the cation. Moreover, they are hyperpolarized and have a lower intracellular pH than wild-type. In order to unravel global physiological processes altered in trk1,2 mutants, we have established conditions at which both wild-type and mutants can grow at different rates. Using a combination of physiological, biochemical and proteomic approaches, we show that during growth at suboptimal potassium concentrations, double trk1,2 mutants accumulate less potassium and reach lower yields. In contrast, the mutants maintain increased viability in the stationary phase and retain more potassium. Moreover, the mutants show increased expression of stress-related proteins such as catalase T, thioredoxin peroxidase or hexokinase 2, suggesting that they are better adapted to the additional stress factors associated with entry into stationary growth phase.
authors.affiliation: 1Department of Microbiology, University of Córdoba, Córdoba, Spain.
authors.forename: Samuel
authors.initials: S
authors.lastname: Gelis
authors.affiliation: 2Department of Chemical and Biological Sciences, Biomedicine Science Institute, Autonomous University of Ciudad Juarez, Ciudad Juarez, Chihuahua, Mexico.
authors.forename: Raquel
authors.initials: R
authors.lastname: González-Fernández
authors.affiliation: 3Escuela de Biotecnología, Universidad Latina de Panamá, Panama 1Department of Microbiology, University of Córdoba, Córdoba, Spain.
authors.forename: Rito
authors.initials: R
authors.lastname: Herrera
authors.affiliation: 4Department of Biochemistry and Molecular Biology, University of Córdoba, Córdoba, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Jorrín
authors.affiliation: 1Department of Microbiology, University of Córdoba, Córdoba, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Ramos
mesh_terms: D018533:Biomass; D027682:Cation Transport Proteins / Q000172:deficiency*; D050296:Microbial Viability; D011188:Potassium / Q000378:metabolism*; D020543:Proteome / Q000032:analysis*; D012441:Saccharomyces cerevisiae / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000032:analysis*
chemical_list: D027682:Cation Transport Proteins; D020543:Proteome; D029701:Saccharomyces cerevisiae Proteins; C085258:TRK2 protein, S cerevisiae; C068664:TRK1 protein, S cerevisiae; D011188:Potassium