The glutathione peroxidase homologous gene from Chlamydomonas reinhardtii is transcriptionally up-regulated by singlet oxygen
The glutathione peroxidase homologous gene from Chlamydomonas reinhardtii is transcriptionally up-regulated by singlet oxygen
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DOI：
10.1023/a:1010601424452
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发表时间：
2001-07-01
影响因子：
5.1
通讯作者：
Eggen, RIL
中科院分区：
文献类型：
--
作者：
Leisinger, U;Rüfenacht, K;Eggen, RIL
莱茵衣藻中的谷胱甘肽过氧化物酶同源基因（Gpxh 基因）在氧化应激条件下上调。 Gpxh 基因表现出对产生单线态氧的光敏剂中性红、亚甲蓝和玫瑰红的非常强和快速的诱导。当暴露于有机氢过氧化物叔丁基过氧化氢(t-BOOH)和异丙苯过氧化氢时，Gpxh mRNA水平显着增加，尽管速度慢得多。相比之下，暴露于产生超氧化物的化合物百草枯和过氧化氢仅微弱地诱导 Gpxh mRNA 水平。 Gpxh mRNA 水平与热休克蛋白 HSP70A 和铁超氧化物歧化酶基因的比较显示，在测试的氧化应激条件下，这三个基因存在定性和定量差异。 Gpxh 基因由单线态氧光敏剂特异性诱导，而其他化合物对 Gpxh 的相对诱导作用比其他研究基因弱得多。使用与芳基硫酸酯酶报告基因融合的 Gpxh 启动子，我们发现单线态氧光敏剂在转录上调 Gpxh。还表明，Gpxh 启动子包含转录起始上游 104 至 179 bp 之间的区域，该区域负责暴露于 O-1(2) 而非 t-BOOH 后的 mRNA 上调。在该区域内，在 16 bp 回文中鉴定出与哺乳动物 cAMP 反应元件 (CRE) 和激活蛋白 1 (AP-1) 结合位点同源的调节序列。
The glutathione peroxidase homologous gene (Gpxh gene) in Chlamydomonas reinhardtii is up-regulated under oxidative stress conditions. The Gpxh gene showed a remarkably strong and fast induction by the singlet oxygen-generating photosensitizers neutral red, methylene blue and rose Bengal. The Gpxh mRNA levels strongly increased, albeit much more slowly, upon exposure to the organic hydroperoxides tert-butyl hydroperoxide (t-BOOH) and cumene hydroperoxide. In contrast, the Gpxh mRNA levels were only weakly induced by exposure to the superoxide-generating compound paraquat and by hydrogen peroxide. A comparison of the Gpxh mRNA levels with those of the heat shock protein HSP70A and the iron superoxide dismutase gene showed qualitative and quantitative differences for the three genes under oxidative stress conditions tested. The Gpxh gene is specifically induced by singlet-oxygen photosensitizers and the relative induction by other compounds is much weaker for Gpxh than for the other genes investigated. Using Gpxh promoter fusions with the arylsulfatase reporter gene, we have shown that the Gpxh was transcriptionally up-regulated by singlet-oxygen photosensitizers. It is also shown that the Gpxh promoter contains a region between 104 and 179 bp upstream of the transcription start that is responsible for the mRNA up-regulation upon exposure to O-1(2) but not t-BOOH. Within this region a regulatory sequence homologous to the mammalian cAMP response element (CRE) and activator protein 1 (AP-1) binding site was identified within a 16 bp palindrome.