title: Involvement of thioredoxin peroxidase type II (Ahp1p) of Saccharomyces cerevisiae in Mn2+ homeostasis.
abstract: To identify new proteins involved in Mn2+ homeostasis, we isolated Mn(2+)-resistant mutants of Saccharomyces cerevisiae starting from a calcineurin-deficient, Mn2+ hypersensitive strain (delta cmp1 delta cmp2). The mutations were found to lie in the PMR1 gene, known to encode a "P-type" Ca(2+)-ATPase that transports Ca2+ and Mn2+ from the cytosol to the Golgi apparatus. A second gene, AHP1, was cloned as a suppressor of the Mn2+ tolerance of a delta cmp1 delta cmp2 pmr1 mutant. Ahp1p was recently described as a thioredoxin peroxidase type II, an antioxidant protein with alkyl hydroperoxide defense properties in yeast. AHP1 disruption in strain W303 decreased tolerance to Mn2+ and H2O2. We found that a GFP-Ahp1p fusion construct was in the cytosol when cells were grown in glucose, and in the mitochondria when cells were grown in oleate. Based on Mn2+ transport data, we concluded that Ahp1p is involved in cellular Mn2+ homeostasis in trafficking of Mn2+ from cytosol to mitochondria and from cytosol for export across the plasma membrane.
authors.affiliation: Department of Fermentation Technology, Faculty of Engineering, Hiroshima University, Japan.
authors.forename: I C
authors.initials: IC
authors.lastname: Farcasanu
authors.forename: D
authors.initials: D
authors.lastname: Hirata
authors.forename: E
authors.initials: E
authors.lastname: Tsuchiya
authors.forename: K
authors.initials: K
authors.lastname: Mizuta
authors.forename: T
authors.initials: T
authors.lastname: Miyakawa
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics; D019703:Calcineurin / Q000235:genetics; D000252:Calcium-Transporting ATPases / Q000235:genetics; D003001:Cloning, Molecular; D003600:Cytosol / Q000378:metabolism; D005816:Genetic Complementation Test; D005838:Genotype; D006706:Homeostasis; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008345:Manganese / Q000378:metabolism* / Q000494:pharmacology; D008928:Mitochondria / Q000378:metabolism; D018832:Molecular Chaperones; D016296:Mutagenesis; D010544:Peroxidases / Q000378:metabolism*; D054464:Peroxiredoxins; D011994:Recombinant Proteins / Q000378:metabolism; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins
chemical_list: C515936:AHP1 protein, S cerevisiae; D018528:ATP-Binding Cassette Transporters; D018832:Molecular Chaperones; D011994:Recombinant Proteins; C101767:SSC1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D008345:Manganese; D006861:Hydrogen Peroxide; D010544:Peroxidases; D054464:Peroxiredoxins; D019703:Calcineurin; D000252:Calcium-Transporting ATPases