Title A unique thioredoxin reductase plays defensive roles against oxidative, nitrosative and nutritional stresses in Schizosaccharomyces pombe
Author Dam-Jung Ji1, Chang-Jin Lim1, and Kyunghoon Kim2*
Address 1Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon 24341, Republic of Korea, 2Department of Biological Sciences, College of Natural Sciences, Kangwon National University, Chuncheon 24341, Republic of Korea
Bibliography Korean Journal of Microbiology, 52(1),1-9, 2016
DOI http://dx.doi.org/10.7845/kjm.2016.6004
Key Words Schizosaccharomyces pombe, glutathione, hydrogen peroxide, nitric oxide, nitrogen starvation, reactive oxygen species, superoxide anion
Abstract A unique Schizosaccharomyces pombe TrxR + gene encoding thioredoxin reductase (TrxR) was found to be positively regulated by stress-inducing agents through the stress-responsive transcription factor Pap1. In the present study, the protective roles of S. pombe TrxR were evaluated using the TrxR-overexpressing recombinant plasmid pHSM10. In the presence of hydrogen peroxide (H2O2) and superoxide anion-generating menadione (MD), S. pombe TrxR increased cellular growth and the total glutathione (GSH) level, while it reduced levels of intracellular reactive oxygen species (ROS). The nitric oxide (NO) levels of the TrxR-overexpressing cells, in the presence of H2O2 and MD, were maintained to be similar to those of the corresponding non-treated cells. Although S. pombe TrxR was able to scavenge NO generated by sodium nitroprusside (SNP), it had no significant modulating effects on cellular growth, ROS levels, or the total GSH level of SNP-exposed yeast cells, compared with the differences in those of the two non-treated cell cultures. TrxR increased the cellular growth and total GSH level, which were diminished by nitrogen starvation. It also scavenged ROS and NO produced during nitrogen starvation. Taken together, the S. pombe TrxR protects against oxidative, nitrosative, and nutritional stresses
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