Diverse fission yeast genes required for responding to oxidative and metal stress: Comparative analysis of glutathione‐related and other defense gene deletions

Abstract

Living organisms have evolved multiple sophisticated mechanisms to deal with reactive oxygen species. We constructed a collection of twelve single-gene deletion strains of the fission yeast Schizosaccharomyces pombe designed for the study of oxidative and heavy metal stress responses. This collection contains deletions of biosynthetic enzymes of glutathione (Dgcs1 and Dgsa1), phytochelatin (Dpcs2), ubiquinone (Dabc1) and ergothioneine (Degt1), as well as catalase (Dctt1), thioredoxins (Dtrx1 and Dtrx2), Cu/Zn-and Mn-superoxide dismutases (SODs; Dsod1 and Dsod2), sulfiredoxin (Dsrx1) and sulfide-quinone oxidoreductase (Dhmt2). First, we employed metabolomic analysis to examine the mutants of the glutathione biosynthetic pathway. We found that ophthalmic acid was produced by the same enzymes as glutathione in S. pombe. The identical genetic background of the strains allowed us to assess the severity of the individual gene knockouts by treating the deletion strains with oxidative agents. Among other results, we found that glutathione deletion strains were not particularly sensitive to peroxide or superoxide, but highly sensitive to cadmium stress. Our results show the astonishing diversity in cellular adaptation mechanisms to various types of oxidative and metal stress and provide a useful tool for further research into stress responses.

The contribution of non-essentialSchizosaccharomyces pombegenes to fitness in response to altered nutrient supply and target of rapamycin activity

“…Deletion of hmt2 (a sulfide-quinone oxidoreductase), mni1 (an exon junction regulating factor), pha2 (a phrenate dehydratase) SPCC320.03 (a transcription factor) and SPCC794.03 (an amino acid permease) each impacted upon cell fitness in all three minimal nutrient environments tested (electronic supplementary material, figure S2). Importantly, mutations of these genes have previously been associated with altered viability when starved for nitrogen [24][25][26].…”

Nitrogen signaling factor triggers a respiration-like gene expression program

“…gst3 + was not required for NSF-mediated adaptive growth, neither in our screen nor in growth assays performed with newly generated gst3Δ cells (Figure S3D). hmt2 + was identified by our genetic screen to be required for growth on EMM media (Table S1 and Figure S3D), which can be explained by the cysteine auxotrophy of hmt2Δ cells (Pluskal et al , 2016). Because our screen was conducted in EMM, hmt2 + was thus not revealed as a gene necessary for NSF-mediated adaptive growth.…”

Genome-wide quantification of contributions to sexual fitness identifies genes required for spore viability and health in fission yeast

“…For example, SPAC27E2 . 01 and Hmt2 are auxotrophic for arginine [ 50 ] and cysteine [ 51 ], respectively. In addition to auxotrophy, SPAC27E2 .…”

“…However, multiple genes annotated with auxotrophy phenotypes also have existing phenotypes in sexual reproduction. For example, SPAC27E2.01 and Hmt2 are auxotrophic for arginine [50] and cysteine [51], respectively. In addition to auxotrophy, SPAC27E2.01 mutants have an annotated defect in sporulation and Hmt2 mutants have an annotated defect in meiotic chromosome segregation [17].…”