title: OxyR2 Modulates OxyR1 Activity and Vibrio cholerae Oxidative Stress Response.
abstract: Bacteria have developed capacities to deal with different stresses and adapt to different environmental niches. The human pathogenVibrio cholerae, the causative agent of the severe diarrheal disease cholera, utilizes the transcriptional regulator OxyR to activate genes related to oxidative stress resistance, including peroxiredoxin PrxA, in response to hydrogen peroxide. In this study, we identified another OxyR homolog inV. cholerae, which we named OxyR2, and we renamed the previous OxyR OxyR1. We found that OxyR2 is required to activate its divergently transcribed geneahpC, encoding an alkylhydroperoxide reductase, independently of H2O2A conserved cysteine residue in OxyR2 is critical for this function. Mutation of eitheroxyR2orahpCrenderedV. choleraemore resistant to H2O2RNA sequencing analyses indicated that OxyR1-activated oxidative stress-resistant genes were highly expressed inoxyR2mutants even in the absence of H2O2Further genetic analyses suggest that OxyR2-activated AhpC modulates OxyR1 activity by maintaining low intracellular concentrations of H2O2Furthermore, we showed that ΔoxyR2and ΔahpCmutants were less fit when anaerobically grown bacteria were exposed to low levels of H2O2or incubated in seawater. These results suggest that OxyR2 and AhpC play important roles in theV. choleraeoxidative stress response.
authors.affiliation: Department of Microbiology, Nanjing Agricultural University, Nanjing, China wanghui@njau.edu.cn junzhu@mail.med.upenn.edu.
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Nawar
authors.initials: N
authors.lastname: Naseer
authors.affiliation: Department of Microbiology, Nanjing Agricultural University, Nanjing, China.
authors.forename: Yaran
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Harriton High School, Bryn Mawr, Pennsylvania, USA.
authors.forename: Anthony Y
authors.initials: AY
authors.lastname: Zhu
authors.affiliation: Department of Microbiology, Nanjing Agricultural University, Nanjing, China.
authors.forename: Xuewen
authors.initials: X
authors.lastname: Kuai
authors.affiliation: Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Nirupa
authors.initials: N
authors.lastname: Galagedera
authors.affiliation: Department of Biotechnology, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA wanghui@njau.edu.cn junzhu@mail.med.upenn.edu.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002771:Cholera / Q000382:microbiology; D015964:Gene Expression Regulation, Bacterial; D023061:Gene Order; D051379:Mice; D050296:Microbial Viability / Q000235:genetics; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D017382:Reactive Oxygen Species; D017384:Sequence Deletion; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D014734:Vibrio cholerae / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D017382:Reactive Oxygen Species; D014157:Transcription Factors
keywords: AhpC; OxyR; ROS resistance; V. cholerae; reactive oxygen species