title: Protein phosphatase 2B of Saccharomyces cerevisiae is required for tolerance to manganese, in blocking the entry of ions into the cells.
abstract: The role of protein phosphatase 2B (PP2B/calcineurin) of Saccharomyces cerevisiae in the tolerance to divalent cations was investigated. PP2B-deficient mutants were found to be sensitive to MnCl2, but not to ZnCl2, CuCl2, NiCl2 and CoCl2. By measuring both manganese uptake and its efflux, it was found that the sensitivity of the mutant cells was due to an increase in manganese uptake and that the wild-type cells were able to prevent manganese entry into the cells, rather than export it in a more efficient manner. In the presence of the immunosuppressant FK506, the behavior of wild-type cells became similar to that of PP2B mutants. Out of various divalent cations tested, externally added magnesium ions were able to block manganese uptake in both wild-type and PP2B mutant strains.
authors.affiliation: Department of Fermentation Technology, 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: F
authors.initials: F
authors.lastname: Nishiyama
authors.forename: T
authors.initials: T
authors.lastname: Miyakawa
mesh_terms: D001692:Biological Transport / Q000187:drug effects; D004352:Drug Resistance, Microbial; D007166:Immunosuppressive Agents / Q000494:pharmacology; D008274:Magnesium / Q000494:pharmacology; D008345:Manganese / Q000378:metabolism* / Q000493:pharmacokinetics; D009154:Mutation; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D016559:Tacrolimus / Q000494:pharmacology
chemical_list: D007166:Immunosuppressive Agents; D008345:Manganese; D010749:Phosphoprotein Phosphatases; D008274:Magnesium; D016559:Tacrolimus