Oxidant regulation of the Saccharomyces cerevisiae GSH1 gene.

Glutathione (gamma-L-glutamyl-L-cysteinylglycine) is an important antioxidant molecule, helping to protect the cell against oxidative stress. Expression of the Saccharomyces cerevisiae GSH1 gene, coding for the first enzyme involved in glutathione biosynthesis, is regulated at the level of transcription by oxidants and heavy metals. We have characterised the sequences of the GSH1 promoter responsible for the amino acid-dependent H(2)O(2) regulation of transcription.

The adaptive response of Saccharomyces cerevisiae to mercury exposure.

The budding yeast Saccharomyces cerevisiae has been shown to possess a number of discrete but overlapping adaptive stress responses. We show here that yeast has an adaptive stress response towards mercury and that this response overlaps to some extent with the H(2)O(2) and cadmium-inducible stress responses. Expression of the yeast GSH1 gene, encoding gamma-glutamylcysteine synthetase, is known to be regulated by hydrogen peroxide; in this study we show that expression of a GSH1-lacZ reporter gene is shown to be regulated by exposure to heavy metals, such as mercury and cadmium.