{"title":"多种变量影响艰难梭菌精细校准的抗氧化防御能力。","authors":"Erin B Purcell","doi":"10.1128/mbio.02544-24","DOIUrl":null,"url":null,"abstract":"<p><p>The obligate anaerobe <i>Clostridioides difficile</i> encodes multiple reductases to detoxify molecular oxygen and reactive oxygen species. Caulat and colleagues have characterized the activity and regulation of four such reductases (L. C. Caulat, A. Lotoux, M. C. Martins, N. Kint, et al., mBio 15:e01591-24, 2024, https://doi.org/10.1128/mbio.01591-24). Each proved critical for clostridial survival in a different range of oxygen concentrations; together, they ameliorate a broad range of oxidative stress levels. Moreover, two previously uncharacterized regulators were found to control reductase gene expression in response to oxidative stress. The genetic repressor Rex and the reductase FdpF are both sensitive to the NAP<sup>+</sup>:NADH ratio, which is affected by a cell's metabolic state as well as redox activity. While oxygen is known to influence the expression of metabolism genes in <i>C. difficile</i>, the mechanisms for cross-talk between the pathways that respond to oxidative and metabolic stress are not well known. The NADH dependence of Rex and FdpF may represent a newly mapped junction between these pathways.</p>","PeriodicalId":18315,"journal":{"name":"mBio","volume":null,"pages":null},"PeriodicalIF":5.1000,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Multiple variables influence the finely calibrated antioxidant defenses of <i>Clostridioides difficile</i>.\",\"authors\":\"Erin B Purcell\",\"doi\":\"10.1128/mbio.02544-24\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>The obligate anaerobe <i>Clostridioides difficile</i> encodes multiple reductases to detoxify molecular oxygen and reactive oxygen species. Caulat and colleagues have characterized the activity and regulation of four such reductases (L. C. Caulat, A. Lotoux, M. C. Martins, N. Kint, et al., mBio 15:e01591-24, 2024, https://doi.org/10.1128/mbio.01591-24). Each proved critical for clostridial survival in a different range of oxygen concentrations; together, they ameliorate a broad range of oxidative stress levels. Moreover, two previously uncharacterized regulators were found to control reductase gene expression in response to oxidative stress. The genetic repressor Rex and the reductase FdpF are both sensitive to the NAP<sup>+</sup>:NADH ratio, which is affected by a cell's metabolic state as well as redox activity. While oxygen is known to influence the expression of metabolism genes in <i>C. difficile</i>, the mechanisms for cross-talk between the pathways that respond to oxidative and metabolic stress are not well known. The NADH dependence of Rex and FdpF may represent a newly mapped junction between these pathways.</p>\",\"PeriodicalId\":18315,\"journal\":{\"name\":\"mBio\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":5.1000,\"publicationDate\":\"2024-10-30\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"mBio\",\"FirstCategoryId\":\"99\",\"ListUrlMain\":\"https://doi.org/10.1128/mbio.02544-24\",\"RegionNum\":1,\"RegionCategory\":\"生物学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MICROBIOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"mBio","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1128/mbio.02544-24","RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MICROBIOLOGY","Score":null,"Total":0}
引用次数: 0
摘要
难辨梭状芽孢杆菌(Clostridioides difficile)为多种还原酶编码,用于对分子氧和活性氧进行解毒。Caulat 及其同事描述了四种此类还原酶的活性和调控(L. C. Caulat, A. Lotoux, M. C. Martins, N. Kint, et al., mBio 15:e01591-24, 2024, https://doi.org/10.1128/mbio.01591-24)。事实证明,在不同的氧气浓度范围内,每种物质都对梭状芽孢杆菌的生存至关重要;它们共同改善了广泛的氧化应激水平。此外,研究还发现了两种以前未表征的调节因子,它们控制还原酶基因的表达以应对氧化应激。基因抑制因子 Rex 和还原酶 FdpF 都对 NAP+:NADH 比率敏感,而 NAP+:NADH 比率受细胞代谢状态和氧化还原活动的影响。虽然已知氧气会影响艰难梭菌中代谢基因的表达,但对氧化应激和代谢应激做出反应的途径之间的交叉机制还不十分清楚。Rex 和 FdpF 对 NADH 的依赖性可能代表了这些途径之间新绘制的连接点。
Multiple variables influence the finely calibrated antioxidant defenses of Clostridioides difficile.
The obligate anaerobe Clostridioides difficile encodes multiple reductases to detoxify molecular oxygen and reactive oxygen species. Caulat and colleagues have characterized the activity and regulation of four such reductases (L. C. Caulat, A. Lotoux, M. C. Martins, N. Kint, et al., mBio 15:e01591-24, 2024, https://doi.org/10.1128/mbio.01591-24). Each proved critical for clostridial survival in a different range of oxygen concentrations; together, they ameliorate a broad range of oxidative stress levels. Moreover, two previously uncharacterized regulators were found to control reductase gene expression in response to oxidative stress. The genetic repressor Rex and the reductase FdpF are both sensitive to the NAP+:NADH ratio, which is affected by a cell's metabolic state as well as redox activity. While oxygen is known to influence the expression of metabolism genes in C. difficile, the mechanisms for cross-talk between the pathways that respond to oxidative and metabolic stress are not well known. The NADH dependence of Rex and FdpF may represent a newly mapped junction between these pathways.
期刊介绍:
mBio® is ASM''s first broad-scope, online-only, open access journal. mBio offers streamlined review and publication of the best research in microbiology and allied fields.