title: Deletion of the ubiquitin-conjugating enzyme Ubc2 confers resistance to methylmercury in budding yeast by promoting Whi2 degradation.
abstract: Ubiquitin-conjugating enzymes involved in sensitivity to methylmercury in yeast were identified by deletion analysis, which showed that Ubc2- or Ubp13-deficiency conferred resistance to methylmercury. Whi2, which was previously shown to be associated with increased methylmercury toxicity and is intracellularly degraded via the ubiquitin-proteasome system, was expressed at significantly lower levels in Ubc2-deficient yeast than in wild-type yeast. Ubc2/Whi2 double-deficient yeast showed neither an additive nor synergistic increase in methylmercury resistance. Our results indicate that Ubc2 may increase the sensitivity to methylmercury in yeast by inhibiting the proteasomal degradation of Whi2.
authors.affiliation: Laboratory of Molecular and Biochemical Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan.
authors.forename: Gi-Wook
authors.initials: GW
authors.lastname: Hwang
authors.forename: Fujio
authors.initials: F
authors.lastname: Mastuyama
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Takahashi
authors.forename: Jin-Yong
authors.initials: JY
authors.lastname: Lee
authors.forename: Akira
authors.initials: A
authors.lastname: Naganuma
mesh_terms: D008767:Methylmercury Compounds / Q000378:metabolism / Q000633:toxicity*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism* / Q000502:physiology*; D025801:Ubiquitin / Q000378:metabolism; D044763:Ubiquitin-Conjugating Enzymes / Q000172:deficiency* / Q000378:metabolism / Q000502:physiology*
chemical_list: D008767:Methylmercury Compounds; D029701:Saccharomyces cerevisiae Proteins; D025801:Ubiquitin; C470937:Whi2 protein, S cerevisiae; C471606:RAD6 protein, S cerevisiae; D044763:Ubiquitin-Conjugating Enzymes; D046988:Proteasome Endopeptidase Complex