A genetic approach to study H2O2 scavenging in fission yeast - distinct roles of peroxiredoxin and catalase
A genetic approach to study H2O2 scavenging in fission yeast - distinct roles of peroxiredoxin and catalase
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DOI：
10.1111/mmi.12548
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发表时间：
2014-04-01
影响因子：
3.6
通讯作者：
Hidalgo, Elena
中科院分区：
文献类型：
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作者：
Paulo, Esther;Garcia-Santamarina, Sarela;Hidalgo, Elena
裂殖酵母中的主要过氧化还蛋白Tpx1对维持有氧生长很重要，缺乏该蛋白的细胞在厌氧条件下只能在固体平板上生长。我们发现编码硫氧还蛋白还原酶基因trr1的缺失抑制了Delta tpx1细胞对有氧生长的敏感性，因此缺乏这两种蛋白的细胞能够在有氧的情况下在固体平板上生长。我们研究了这种抑制作用，并确定它依赖于过氧化氢酶的存在，过氧化氢酶在Delta trr1细胞中以转录因子Pap1依赖的方式结构性表达。对裂解酵母中过氧化氢清除活性的完整表征表明，Tpx1是唯一对过氧化氢和细胞丰度具有足够敏感性的酶，可以控制有氧生长过程中产生的低水平过氧化氢，当Delta tpx1细胞中的过氧化氢稳态水平增加时，过氧化氢酶是下一个解毒屏障。GPX1是庞氏链霉菌基因组编码的唯一一种谷胱甘肽过氧化物酶，在加入胞外过氧化物时只起到很小的辅助作用。我们的研究提出了这种真核生物不同的过氧化氢清除活性的非重叠作用。
The main peroxiredoxin in Schizosaccharomyces pombe, Tpx1, is important to sustain aerobic growth, and cells lacking this protein are only able to grow on solid plates under anaerobic conditions. We have found that deletion of the gene coding for thioredoxin reductase, trr1, is a suppressor of the sensitivity to aerobic growth of Delta tpx1 cells, so that cells lacking both proteins are able to grow on solid plates in the presence of oxygen. We have investigated this suppression effect, and determined that it depends on the presence of catalase, which is constitutively expressed in Delta trr1 cells in a transcription factor Pap1-dependent manner. A complete characterization of the repertoire of hydrogen peroxide scavenging activities in fission yeast suggests that Tpx1 is the only enzyme with sufficient sensitivity for peroxides and cellular abundance as to control the low levels produced during aerobic growth, catalase being the next barrier of detoxification when the steady-state levels of peroxides are increased in Delta tpx1 cells. Gpx1, the only glutathione peroxidase encoded by the S. pombe genome, only has a minor secondary role when extracellular peroxides are added. Our study proposes non-overlapping roles for the different hydrogen peroxide scavenging activities of this eukaryotic organism.