A chromate-tolerant mutant chr1-663T bearing a stable one-gene mutation and its parental strain 6chr(+) were used to investigate the background of Cr(VI) tolerance in the fission yeast Schizosaccharomyces pombe. The mutant chr1-663T displayed a significantly decreased specific glutathione reductase (GR) activity coded by the pgr1 (+) gene compared with its parental strain. Transformants of the mutant chr1-663T with a nonintegrative pUR18N vector expressing the pgr1 (+) gene exhibited the same Cr(VI) sensitivity and specific GR activity as their parental strain, demonstrating the importance of the GR-NADPH system in Cr(VI) tolerance. Transformants, nevertheless, exhibited an increased intracellular peroxide concentration, a decreased Cr(VI)-reducing and HO*-producing ability, which suggested an unbalanced oxidoreduction state of cells and partial complementation of the GR function. No mutation was found in the sequences of the pgr1 (+) and the pap1 (+) (transcriptional regulatory gene of GR) genes of the Cr(VI)-tolerant mutant by sequence analysis.

• MeSH
• chromany metabolismus   farmakologie   MeSH
• down regulace * MeSH
• fungální léková rezistence MeSH
• glutathionreduktasa genetika   metabolismus   MeSH
• mutace * MeSH
• oxidace-redukce MeSH
• proteiny asociované s pankreatitidou MeSH
• Schizosaccharomyces pombe - proteiny genetika   metabolismus   MeSH
• Schizosaccharomyces účinky léků   enzymologie   genetika   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chromany MeSH
• glutathionreduktasa MeSH
• proteiny asociované s pankreatitidou MeSH
• REG3A protein, human MeSH Prohlížeč
• Schizosaccharomyces pombe - proteiny MeSH

Stable chromium(VI)-sensitive and -tolerant mutants were obtained by induced mutagenesis of Schizosaccharomyces pombe lysine and leucine auxotrophic heterothallic strains 6chr+ and 9chr+. Eleven of them were selected for further studies. Fast transport of 51CrO4(2-) was detected in a representative sensitive mutant, chr-51S, while the tolerant mutant chr1-66T and the parental strain 6chr+ exhibited significantly lower 51CrO4(2-) uptake. The segregation of tetrads of three selected CrVI-tolerant mutants, chr1-66T, chr1-14T and chr2-04T, strongly indicated that tolerance was determined by single mutations. Random spore analysis proved that the mutations of chr1-66T and chr1-14T were allelic and the mutation of mutant chr2-04T was not allelic with the mutation of chr1-66T. Recombinants carrying the ura4D18 selective marker were created for transformation experiments. Two of them (chr1-661T and chr2-046T) can be used to clone and identify the genes responsible for their CrVI tolerance phenotype.

• MeSH
• alely MeSH
• antifungální látky metabolismus   farmakologie   MeSH
• biologický transport MeSH
• chrom metabolismus   farmakologie   MeSH
• dominantní geny MeSH
• fungální léková rezistence genetika   MeSH
• geny hub MeSH
• kinetika MeSH
• kovy metabolismus   MeSH
• křížení genetické MeSH
• mikrobiální testy citlivosti MeSH
• mutace MeSH
• počet mikrobiálních kolonií MeSH
• rekombinace genetická MeSH
• Schizosaccharomyces účinky léků   genetika   růst a vývoj   metabolismus   MeSH
• testy genetické komplementace MeSH
• transformace genetická MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antifungální látky MeSH
• chrom MeSH
• chromium hexavalent ion MeSH Prohlížeč
• kovy MeSH