Activation of the Oxidative Stress Regulator PpYap1 through Conserved Cysteine Residues during Methanol Metabolism in the YeastPichia pastoris

Expression of the Laccase Gene from a White Rot Fungus in Pichia pastoris Can Enhance the Resistance of This Yeast to H 2 O 2 -Mediated Oxidative Stress by Stimulating the Glutathione-Based Antioxidative System

“…PpYAP1 can act as a regulator of the redox system in Pichia pastoris. It plays an important role in the defense against oxidative stress by activating the expression of other antioxidative genes involved in the glutathione-based antioxidant system (55,56). Based on our results and previous research, we propose the following hypothesis to address the issue of how laccase expression is linked to defense mechanisms like enhanced glutathione production.…”

“…This causes strong oxidative stress. The glutathione redox system, which includes synthesis and recycling, has been found to play an important role in scavenging hydrogen peroxide, detoxifying reactive oxygen species, and protecting against oxidative stress in Pichia pastoris (55,56,58). We have previously cloned and characterized a laccase gene, lac5930-1, and its corresponding full-length cDNA from white rot fungus Trametes sp.…”

Msn5p Is Involved in Formaldehyde Resistance but Not in Oxidative Stress Response in the Methylotrophic YeastCandida boidinii

“…In addition, a transcription factor termed Yap1p plays an important role in the upregulation of GSH-related enzymes in P. pastoris. 15,16) In that the PpYap1p-depleted strain proved sensitive to H 2 O 2 but not to HCHO, methylotrophic yeasts must have an alternative transcriptional regulatory system to controll the expression of the genes for HCHO resistance.To date, in the budding yeast Saccharomyces cerevisiae, stress-inducible transcription factors Msn2p/ Msn4p and heat shock protein Ssa4p, and their carrier Msn5p, have been reported to play important roles in protecting cells from stress-induced cell death. [17][18][19][20][21] Among these factors, we focused on Msn5p, which belongs to the importin-family and participates in the nuclear export of several proteins.…”

“…In addition, a transcription factor termed Yap1p plays an important role in the upregulation of GSH-related enzymes in P. pastoris. 15,16) In that the PpYap1p-depleted strain proved sensitive to H 2 O 2 but not to HCHO, methylotrophic yeasts must have an alternative transcriptional regulatory system to controll the expression of the genes for HCHO resistance.…”

The Peroxisomal Catalase Gene in the Methylotrophic YeastPichia methanolica

“…Recently, the mechanisms by which methylotrophic yeasts respond to oxidative stress derived from H 2 O 2 or other reactive oxygen species (ROS) were elucidated in P. pastoris. 18,19) This knowledge should improve the utility of the P. methanolica gene expression system, as it is necessary to understand not only the scavenging system for ROS but also the mechanism of response to ROS.…”