methionine synthase: expression analysis and requirement for virulence Free

Abstract

This paper describes (i) the expression profile of the methionine synthase gene () in the human pathogenic fungus and (ii) the phenotypes of a mutant. In contrast to the gene, which showed no significant change in expression in any environmental condition tested, the gene showed a substantial induction in response to methionine and a dramatic transcriptional induction in response to homocysteine. Like a mutant, the mutant was a methionine auxotroph. However, relative to a mutant, the mutant grew very slowly and was less heat-shock resistant. In contrast to a mutant, the mutant lost viability when starved of methionine, and it was deficient in capsule formation. Like a mutant, the mutant was avirulent. In contrast to a mutant, the mutant was hypersensitive to fluconazole and to the calcineurin inhibitors FK506 and cyclosporin A. A synergistic fungicidal effect was also found between each of these drugs and . The phenotypic differences between the and mutants may be due to the accumulation in mutants of homocysteine, a toxic metabolic intermediate that inhibits sterol biosynthesis.

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2004-09-01
2024-03-29
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