title: Impaired cell envelope resulting from arcA mutation largely accounts for enhanced sensitivity to hydrogen peroxide in Shewanella oneidensis.
abstract: Oxidative stress is one of the major challenges that Shewanella encounter routinely because they thrive in redox-stratified environments prone to reactive oxygen species (ROS) formation, letting alone that ROS can be generated endogenously. As respiration is the predominant process for endogenous ROS, regulators mediating respiration have been demonstrated and/or implicated to play a role in oxidative stress response. In our efforts to unveil the involvement of global regulators for respiration in the oxidative stress response, we found that loss of the Arc system increases S. oneidensis sensitivity to H2O2 whereas neither Fnr nor Crp has a significant role. A comparison of transcriptomic profiles of the wild-type and its isogenic arcA mutant revealed that the OxyR regulon is independent of the Arc system. We then provided evidence that the enhanced H2O2 sensitivity of the arcA mutant is due to an increased H2O2 uptake rate, a result of a cell envelope defect. Although one of three proteases of the ArcA regulon when in excess is partially accountable for the envelope defect, the major contributors remain elusive. Overall, our data indicate that the Arc system influences the bacterial cell envelope biosynthesis, a physiological aspect that has not been associated with the regulator before.
authors.affiliation: Institute of Microbiology and College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
authors.forename: Fen
authors.initials: F
authors.lastname: Wan
authors.affiliation: Institute of Microbiology and College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
authors.forename: Yinting
authors.initials: Y
authors.lastname: Mao
authors.affiliation: Institute of Microbiology and College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Dong
authors.affiliation: Institute of Microbiology and College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Ju
authors.affiliation: Institute of Microbiology and College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
authors.forename: Genfu
authors.initials: G
authors.lastname: Wu
authors.affiliation: Institute of Microbiology and College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
authors.forename: Haichun
authors.initials: H
authors.lastname: Gao
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D002462:Cell Membrane / Q000187:drug effects* / Q000235:genetics; D024202:Electrophoretic Mobility Shift Assay; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000235:genetics*; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D018384:Oxidative Stress / Q000235:genetics / Q000502:physiology; D012097:Repressor Proteins / Q000235:genetics*; D020592:Shewanella / Q000235:genetics*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; D012097:Repressor Proteins; C041610:arcA protein, E coli; C499299:oxyR protein, E coli; D006861:Hydrogen Peroxide