Regulation of gene expression by active oxygen species

活性氧对基因表达的调节

• 批准号: 06454638
• 负责人: YONEI Shuji
• 金额: $ 3.58万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06454638/
• 关键词: Redox; SoxRS; Thioredoxin; Active oxygen species; DNA repair; Signal transfer; Oxidative stress; Gene expression; soi遺伝子; 活性酵素; mutM遺伝子; soxRSレギュロン; スーパーオキサイド

The ability of Escherichia coli thioredoxin and thioredoxin reductase was examined with respect to protect the cells against hydrogen peroxide (H_2O_2) and super-oxide-generating agents. In late stationary phase, thioredoxin-and thioredoxin reductase-deficient mutant, trxA and trxB,respectively, exhibited increased sensitivity to these oxidizing agents compared with wild-type strain. Exponentially growing cells of trxA mutant was also more sensitive to H_2O_2 than wild-type strain. On the other hand, trxB mutant in exponentially growing phase acquired resistance to H_2O_2 over the level of wild-type strain. Catalase-hydroperoxidase I (HPI), encoded by the katG,is known to be the major defense enzyme against peroxides and inducible by H_2O_2. We examined the level of HPI expression in trxA and trxB mutants after treatment with H_2O_2. Interestingly, the trxB mutation stimulated the expression of katG : : lacZ fusion gene, while the trxA reduced. These results suggested that thioredoxin protects E.coli cells against H_2O_2 by at least two different mechanisms, by serving as a radical scavenger in its reduced form and by stimulating the induction of HPI in its oxidized form.

研究了大肠杆菌硫氧还蛋白和硫氧还蛋白还原酶对过氧化氢（H_2O_2）和超氧化物发生剂的保护能力。在后期稳定期，硫氧还蛋白和硫氧还蛋白还原酶缺陷型突变体，trxA和trxB，分别表现出增加的敏感性，这些氧化剂相比，野生型菌株。trxA突变株的细胞指数生长对H_2O_2的敏感性也高于野生型。另一方面，处于指数生长期的trxB突变株对H_2O_2的抗性高于野生型菌株。过氧化氢酶-过氧化氢过氧化物酶I（HPI）由katG编码，是植物体内抗过氧化物的主要防御酶，可被H_2O_2诱导。我们检测了H_2O_2处理后trxA和trxB突变体中HPI的表达水平。有趣的是，trxB突变刺激katG：：lacZ融合基因的表达，而trxA降低。这些结果表明，硫氧还蛋白至少通过两种不同的机制来保护大肠杆菌细胞免受H_2O_2的侵害，即通过还原形式的自由基清除剂和刺激氧化形式的HPI的诱导。

项目成果

Zhang QM, T Takamoto and S Yonei: "Molecular cloning and characterization of new members of the SoxRS regulon in Escherichia coli" ibid.1. 281-282 (1994)

张QM，T Takamoto和S Yonei：“大肠杆菌中SoxRS调节子新成员的分子克隆和表征”同上。1。

Yonei, S.and Q.M.Zhang: "Regulation of adaptive responses to oxidative stress" Environ.Mutagen Res.Comm.16(in Japanese). 345-355 (1995)

Yonei, S. 和 Q.M.Zhang：“氧化应激适应性反应的调节”Environ.Mutagen Res.Comm.16（日语）。

米井脩治、張秋梅: "酸化的スレトスによる遺伝子発現とその制御" 環境変異原研究. 16. 345-355 (1995)

米内修二，张秋梅：“基因表达及其氧化威胁的调节”环境诱变剂研究 16. 345-355 (1995)。

Yonei, S.and Q.M.Zhang: "Current reviews of anti-oxidant researches" Saishin Igaku. 49(in Japanese). 2260-2266 (1994)

Yonei, S. 和 Q.M.Zhang：“抗氧化研究的最新评论”Saishin Igaku。

Yonei, S.and Q.M.Zhang: "Oxygen metabolism in bacterial cells" in : Active Oxugen Species in Foods and Medicine, Edited by M.Inoue, Kyoritu Shuppan, Tokyo. (in Japanese).

Yonei, S. 和 Q.M.Zhang：“细菌细胞中的氧代谢”，《食品和医学中的活性氧种类》，M.Inoue 编辑，Kyoritu Shuppan，东京。