title: Illumina identification of RsrA, a conserved C2H2 transcription factor coordinating the NapA mediated oxidative stress signaling pathway in Aspergillus.
abstract: BACKGROUND
  Chemical mutagenesis screens are useful to identify mutants involved in biological processes of interest. Identifying the mutation from such screens, however, often fails when using methodologies involving transformation of the mutant to wild type phenotype with DNA libraries.
  
  
  RESULTS
  Here we analyzed Illumina sequence of a chemically derived mutant of Aspergillus nidulans and identified a gene encoding a C2H2 transcription factor termed RsrA for regulator of stress response. RsrA is conserved in filamentous fungal genomes, and upon deleting the gene in three Aspergillus species (A. nidulans, A. flavus and A. fumigatus), we found two conserved phenotypes: enhanced resistance to oxidative stress and reduction in sporulation processes. For all species, rsrA deletion mutants were more resistant to hydrogen peroxide treatment. In depth examination of this latter characteristic in A. nidulans showed that upon exposure to hydrogen peroxide, RsrA loss resulted in global up-regulation of several components of the oxidative stress metabolome including the expression of napA and atfA, the two bZIP transcription factors mediating resistance to reactive oxygen species (ROS) as well as NapA targets in thioredoxin and glutathione systems. Coupling transcriptional data with examination of ΔrsrAΔatfA and ΔrsrAΔnapA double mutants indicate that RsrA primarily operates through NapA-mediated stress response pathways. A model of RsrA regulation of ROS response in Aspergillus is presented.
  
  
  CONCLUSIONS
  RsrA, found in a highly syntenic region in Aspergillus genomes, coordinates a NapA mediated oxidative response in Aspergillus fungi.
authors.forename: Jin Woo
authors.initials: JW
authors.lastname: Bok
authors.forename: Philipp
authors.initials: P
authors.lastname: Wiemann
authors.forename: Graeme S
authors.initials: GS
authors.lastname: Garvey
authors.forename: Fang Yun
authors.initials: FY
authors.lastname: Lim
authors.forename: Brian
authors.initials: B
authors.lastname: Haas
authors.forename: Jennifer
authors.initials: J
authors.lastname: Wortman
authors.affiliation: Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA. npkeller@wisc.edu.
authors.forename: Nancy P
authors.initials: NP
authors.lastname: Keller
mesh_terms: D001230:Aspergillus / Q000166:cytology / Q000187:drug effects / Q000235:genetics*; D015139:Blotting, Southern; D002855:Chromatography, Thin Layer; D017124:Conserved Sequence; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D005816:Genetic Complementation Test; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008540:Meiosis / Q000187:drug effects; D008938:Mitosis / Q000187:drug effects; D008954:Models, Biological; D018384:Oxidative Stress / Q000187:drug effects / Q000235:genetics; D010641:Phenotype; D012098:Reproduction / Q000187:drug effects; D017422:Sequence Analysis, DNA; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D013172:Spores, Fungal / Q000187:drug effects / Q000254:growth & development; D013241:Sterigmatocystin / Q000096:biosynthesis; D026801:Synteny / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D005656:Fungal Proteins; D014157:Transcription Factors; D013241:Sterigmatocystin; D006861:Hydrogen Peroxide