Glutathione, Sulphur and Redox are the key areas around which our lab interests are centred. The major question that we are asking is 'How is glutathione homeostasis maintained in living cells ?' Surrounding this major question are several other questions that become important for our understanding. The principal model systems that we use to address these questions are the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe. Glutathione, γ-glutamyl cysteinyl glycine, an unusual thiol containing tripeptide that is present in high concentrations in almost all eukaryotic cells, plays multiple roles including protection from oxidative stress, maintenance of the cellular redox buffer, in mitochondrial iron-sulphur metabolism, in gene regulation, and in metal and drug detoxification. Glutathione metabolism is intimately linked to sulphur metabolism owing to the presence of the key cysteine residue, and we thus also investigate aspects of sulphur metabolism related to glutathione homeostasis. As the focus is on understanding how glutathione levels are maintained in the cell, we are examining different pathways that contribute towards this maintenance. This includes the high affinity plasma membrane transporter of glutathione that was identified in our lab, the classical and two recently discovered non-classical pathways of glutathione degradation (also discovered in our lab) biosynthesis, organellar compartmentalization and utilization of glutathione. We are attempting to not only understand these different pathways and their regulation in detail, but are interested in integrating these pathways and their regulation into a larger picture of glutathione homeostasis in living cells.
