Relative transcriptions of Aspergillus nidulans dug1-3 (orthologes of Saccharomyces cerevisiae DUG - deficient in utilization of glutathione - pathway genes) and ggtA encoding γ-glutamyl transpeptidase were studied under conditions inducing glutathione degradation. GgtA was induced in all cases when glutathione levels decreased, but addition of yeast extract, which moderated glutathione degradation, enhanced its induction. Although dug2 showed constitutive transcription, dug1 and dug3 were induced by carbon and nitrogen starvation and yeast extract did not caused significant changes in their relative transcription. The in silico reconstructed DUG pathway of A. nidulans is a promising candidate for cytosolic GSH degradation induced by carbon/nitrogen stress.
Keywords: Aspergillus nidulans; DUG pathway; Glutathione degradation; carbon stress; γ-glutamyl transpeptidase.