Sulfur metabolites (methionine, cysteine, S-adenosylmethionine, glutathione…) are involved in several vital cellular processes, such as protein synthesis, methylation of macromolecules, or control of the redox balance. Our team is particularly interested in the survival mechanisms set up by the cell in case of deficiency of these sulfur compounds; with the yeast Saccharomyces cerevisiae as a model.
Sulfur metabolism (Fig. 1) is highly conserved throughout evolution. It occupies a special position in cellular function and homeostasis because of the reactivity of thiols and the characteristics of the two sulfur-containing amino acids, methionine and cysteine. In addition to their role in proteins, these amino acids are the precursors of two key cellular compounds: on the one hand, S-adenosylmethionine (SAM), which is the major donor of methyl groups for the methylation of nucleic acids, proteins and lipids; and on the other hand, glutathione (GSH), which is the most abundant antioxidant in cells.