Thioredoxin Peroxidase Is Required for the Transcriptional Response to Oxidative Stress in Budding Yeast

A genetic screen was performed in Saccharomyces cerevisiae to identify mechanisms important for the transcriptional activation of genes encoding antioxidant proteins. Thioredoxin peroxidase, Tsa1p, of the thioredoxin system, was found to be essential for the transcriptional induction of other components of the thioredoxin system, TRX2 (thioredoxin) and TRR1 (thioredoxin reductase), in response to H(2)O(2). The expression of TRX2 and TRR1 is known to be regulated by the transcription factors Yap1p and Skn7p in response to H(2)O(2), and the Tsa1p-dependent regulation of TRX2 requires the Yap1p/Skn7p pathway. The data suggest that expression of components of the thioredoxin system is dependent on the activity of Tsa1p in response to H(2)O(2) in a Yap1p/Skn7p-dependent pathway.