OxyR is a key regulator in response to oxidative stress in Streptomyces avermitilis
OxyR is a key regulator in response to oxidative stress in Streptomyces avermitilis
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OxyR 是阿维链霉菌响应氧化应激的关键调节因子
DOI：
10.1099/mic.0.000251
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发表时间：
2016-04-01
期刊：
影响因子：
2.8
通讯作者：
Li, Jilun
中科院分区：
文献类型：
--
作者：
Liu, Xingchao;Sun, Meng;Li, Jilun
研究了H2O2敏感转录调节因子OxyR在阿维链霉菌氧化应激反应中的作用。一个oxyR缺失突变体是更敏感的H2O2和叔丁基过氧化氢比WT菌株，表明OxyR介导的防御系统对H2O2和有机过氧化物。本文提供的证据表明，在用外源性H2O2处理的细胞中，OxyR的氧化形式通过与启动子区的回文序列结合来激活ahpCD的表达。氧化OxyR还诱导其他抗氧化酶（KatA1、KatA2、KatA3和OhrB1）和氧化应激调节剂（CatR、OhrR和sigma（R））的表达。巯基氧化应激调节基因sigR在转录水平上受OxyR的调控。我们的结论是，OxyR是必要的激活sigR从sigma（R）依赖性启动子的转录，以表达一个不稳定的较大的异构体的sigma（R）在氧化应激。在氧化应激反应中，OxyR通过直接调节和级联调节CatR、OhrR和sigma（R）促进H2O2清除酶的快速产生以修复氧化损伤。
The role of the H2O2-sensing transcriptional regulator OxyR in oxidative stress responses in Streptomyces avermitilis was investigated. An oxyR deletion mutant was more sensitive to H2O2 and tert-butyl hydroperoxide than was the WT strain, indicating that OxyR mediates the defensive system against H2O2 and organic peroxide. Evidence presented herein suggests that in cells treated with exogenous H2O2, the oxidized form of OxyR activated expression of ahpCD by binding to a palindromic sequence of the promoter region. Oxidized OxyR also induced expression of other antioxidant enzymes (KatA1, KatA2, KatA3 and OhrB1) and oxidative stress regulators (CatR, OhrR and sigma(R)). The thiol-oxidative stress regulator gene sigR was regulated at the transcription level by OxyR. We conclude that OxyR is necessary to activate transcription of sigR from the sigma(R)-dependent promoter to express an unstable larger isoform of sigma(R) during oxidative stress. In response to oxidative stress, OxyR facilitates rapid production of H2O2-scavenging enzymes to repair oxidative damage through direct regulation and cascaded regulation of CatR, OhrR and sigma(R).