Reactive Carbonyls Induce TOR- and Carbohydrate-Dependent Hormetic Response in Yeast.

The induction of the beneficial and detrimental effects by reactive carbonyl species in yeast has been investigated. In this study, we have presented evidence that glyoxal and methylglyoxal at low concentrations were able to induce a hormetic adaptive response in glucose-grown but not fructose-grown yeast. The hormetic effect was also TOR-dependent. The mutation in genes encoding either TOR1 or TOR2 protein makes yeast highly sensitive to both -dicarbonyls studied. Simultaneous disruption of TOR1 and TOR2 resulted in higher yeast sensitivity to the -dicarbonyls as compared to parental cells, but double mutant survived better under carbonyl stress than its single mutant counterparts. The data obtained are consistent with the previous works which reported high toxicity of the -dicarbonyls and extend them with the report on the beneficial TOR-dependent hormetic effect of glyoxal and methylglyoxal.