title: Involvement of the osrR gene in the hydrogen peroxide-mediated stress response of Corynebacterium glutamicum.
abstract: A transcriptional profile of the H2O2-adapted Corynebacterium glutamicum HA strain reveals a list of upregulated regulatory genes. Among them, we selected ORF NCgl2298, designated osrR and analyzed its role in H2O2 adaptation. The osrR-deleted (ΔosrR) mutant had defective growth in minimal medium, which was even more pronounced in an osrR deletion mutant of an HA strain. The ΔosrR strain displayed increased sensitivity to H2O2. In addition to H2O2 sensitivity, the ΔosrR strain was found to be temperature-sensitive at 37 °C. 2D-PAGE analysis of the ΔosrR mutant found that MetE and several other proteins involved in redox metabolism were affected by the mutation. Accordingly, the NADPH/NADP(+) ratio of the ΔosrR strain (0.85) was much lower than that of the wild-type strain (2.01). In contrast, the NADH/NAD(+) ratio of the mutant (0.54) was considerably higher than that of the wild-type (0.21). Based on these findings, we propose that H2O2-detoxifying metabolic systems, excluding those involving catalase, are present in C. glutamicum and are regulated, in part, by osrR.
authors.affiliation: Department of Biotechnology and Bioinformatics, Korea University, 2511 Sejong-ro, Sejong-si 339-700, Republic of Korea. Electronic address: soypooh@naver.com.
authors.forename: Eun-Ji
authors.initials: EJ
authors.lastname: Hong
authors.affiliation: Department of Biotechnology, The Catholic University of Korea, Bucheon, Gyeonggi 420-743, Republic of Korea. Electronic address: kimp@catholic.ac.kr.
authors.forename: Pil
authors.initials: P
authors.lastname: Kim
authors.affiliation: Department of Biological Engineering, Inha University, Incheon 402-751, Republic of Korea. Electronic address: eungsoo@inha.ac.kr.
authors.forename: Eung-Soo
authors.initials: ES
authors.lastname: Kim
authors.affiliation: Department of Korean Medicine, Semyung University, 65 Semyeong-ro, Jecheon-si, Chungbuk 390-711, Republic of Korea. Electronic address: ykim@semyung.ac.kr.
authors.forename: Younhee
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Biotechnology and Bioinformatics, Korea University, 2511 Sejong-ro, Sejong-si 339-700, Republic of Korea. Electronic address: hlee@korea.ac.kr.
authors.forename: Heung-Shick
authors.initials: HS
authors.lastname: Lee
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D048230:Corynebacterium glutamicum / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D006861:Hydrogen Peroxide / Q000378:metabolism* / Q000494:pharmacology; D009154:Mutation; D018384:Oxidative Stress; D011401:Promoter Regions, Genetic; D017382:Reactive Oxygen Species / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics; D059467:Transcriptome
chemical_list: D001426:Bacterial Proteins; D017382:Reactive Oxygen Species; D012097:Repressor Proteins; D006861:Hydrogen Peroxide; D002374:Catalase
keywords: Corynebacterium; Oxidative stress; Reactive oxygen species