title: The RosR transcription factor is required for gene expression dynamics in response to extreme oxidative stress in a hypersaline-adapted archaeon.
abstract: BACKGROUND
  Previous work has shown that the hypersaline-adapted archaeon, Halobacterium salinarum NRC-1, is highly resistant to oxidative stress caused by exposure to hydrogen peroxide, UV, and gamma radiation. Dynamic alteration of the gene regulatory network (GRN) has been implicated in such resistance. However, the molecular functions of transcription regulatory proteins involved in this response remain unknown.
  
  
  RESULTS
  Here we have reanalyzed several existing GRN and systems biology datasets for H. salinarum to identify and characterize a novel winged helix-turn-helix transcription factor, VNG0258H, as a regulator required for reactive oxygen species resistance in this organism. This protein appears to be unique to the haloarchaea at the primary sequence level. High throughput quantitative growth assays in a deletion mutant strain implicate VNG0258H in extreme oxidative stress resistance. According to time course gene expression analyses, this transcription factor is required for the appropriate dynamic response of nearly 300 genes to reactive oxygen species damage from paraquat and hydrogen peroxide. These genes are predicted to function in repair of oxidative damage to proteins and DNA. In vivo DNA binding assays demonstrate that VNG0258H binds DNA to mediate gene regulation.
  
  
  CONCLUSIONS
  Together these results suggest that VNG0258H is a novel archaeal transcription factor that regulates gene expression to enable adaptation to the extremely oxidative, hypersaline niche of H. salinarum. We have therefore renamed VNG0258H as RosR, for reactive oxygen species regulator.
authors: Center for Systems Biology, Institute for Genome Sciences and Policy, Durham, NC 27710, USA.
authors: Kriti
authors: K
authors: Sharma
authors: Nicholas
authors: N
authors: Gillum
authors: J Lomax
authors: JL
authors: Boyd
authors: Amy
authors: A
authors: Schmid
mesh_terms: D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000235:genetics* / Q000378:metabolism; D016000:Cluster Analysis; D004247:DNA / Q000378:metabolism; D019848:Gene Expression Regulation, Archaeal; D053263:Gene Regulatory Networks; D019617:Halobacterium salinarum / Q000235:genetics / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008969:Molecular Sequence Data; D018384:Oxidative Stress / Q000187:drug effects*; D010269:Paraquat / Q000494:pharmacology; D011485:Protein Binding; D017382:Reactive Oxygen Species / Q000494:pharmacology*; D017386:Sequence Homology, Amino Acid; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D019843:Archaeal Proteins; D017382:Reactive Oxygen Species; D014157:Transcription Factors; D004247:DNA; D006861:Hydrogen Peroxide; D013482:Superoxide Dismutase; D010269:Paraquat