Stephen D W, Jamieson D J
Biomedical Research Centre, Ninewells Hospital, Dundee, UK.
Mol Microbiol. 1997 Jan;23(2):203-10. doi: 10.1046/j.1365-2958.1997.2081572.x.
The tripeptide gamma-L-glutamyl-L-cysteinylglycine (glutathione) is one of the major antioxidant molecules of cells and plays a vital role in buffering the cell against reactive oxygen species and toxic electrophiles. In the yeast Saccharomyces cerevisiae, the first enzyme involved in glutathione biosynthesis, gamma-glutamylcysteine synthetase, is encoded by the GSH1 gene. This study shows that the regulation of the yeast GSH1 gene by oxidants and the heavy metal cadmium is at the level of transcription. We also demonstrate that the regulation of the GSH1 gene by H2O2 depends upon the presence of the amino acids glutamate, glutamine and lysine in the media. Moreover, regulation of the GSH1 gene by H2O2, although requiring the Yap1 protein, appears to be mediated by a mechanism distinct from that which regulates the Yap1-dependent induction of genes encoding thioredoxin (TRX2) and a stress-inducible HSP70 (SSA1) by H2O2.
三肽γ-L-谷氨酰-L-半胱氨酰甘氨酸（谷胱甘肽）是细胞主要的抗氧化分子之一，在缓冲细胞免受活性氧和有毒亲电试剂影响方面发挥着至关重要的作用。在酿酒酵母中，谷胱甘肽生物合成过程中涉及的首个酶——γ-谷氨酰半胱氨酸合成酶，由GSH1基因编码。本研究表明，氧化剂和重金属镉对酵母GSH1基因的调控发生在转录水平。我们还证明，H2O2对GSH1基因的调控取决于培养基中谷氨酸、谷氨酰胺和赖氨酸的存在。此外，H2O2对GSH1基因的调控虽然需要Yap1蛋白，但其介导机制似乎与H2O2调控Yap1依赖性诱导编码硫氧还蛋白（TRX2）和应激诱导型HSP70（SSA1）的基因的机制不同。
