title: OxyR is a key regulator in response to oxidative stress inStreptomyces avermitilis.
abstract: The role of the H2O2-sensing transcriptional regulator OxyR in oxidative stress responses inStreptomyces avermitiliswas investigated. AnoxyRdeletion mutant was more sensitive to H2O2andtert-butyl hydroperoxide than was the WT strain, indicating that OxyR mediates the defensive system against H2O2and organic peroxide. Evidence presented herein suggests that in cells treated with exogenous H2O2, the oxidized form of OxyR activated expression ofahpCDby 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 σR). The thiol-oxidative stress regulator genesigRwas regulated at the transcription level by OxyR. We conclude that OxyR is necessary to activate transcription ofsigRfrom the σR-dependent promoter to express an unstable larger isoform of σRduring 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 σR.
authors.affiliation: State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, PR China.
authors.forename: Xingchao
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, PR China.
authors.forename: Meng
authors.initials: M
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, PR China.
authors.forename: Yaqing
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, PR China.
authors.forename: Renjun
authors.initials: R
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wen
authors.affiliation: State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, PR China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, PR China.
authors.forename: Jilun
authors.initials: J
authors.lastname: Li