title: Core oxidative stress response in Aspergillus nidulans.
abstract: BACKGROUND
  The b-Zip transcription factor AtfA plays a key role in regulating stress responses in the filamentous fungus Aspergillus nidulans. To identify the core regulons of AtfA, we examined genome-wide expression changes caused by various stresses in the presence/absence of AtfA using A. nidulans microarrays. We also intended to address the intriguing question regarding the existence of core environmental stress response in this important model eukaryote.
  
  
  RESULTS
  Examination of the genome wide expression changes caused by five different oxidative stress conditions in wild type and the atfA null mutant has identified a significant number of stereotypically regulated genes (Core Oxidative Stress Response genes). The deletion of atfA increased the oxidative stress sensitivity of A. nidulans and affected mRNA accumulation of several genes under both unstressed and stressed conditions. The numbers of genes under the AtfA control appear to be specific to a stress-type. We also found that both oxidative and salt stresses induced expression of some secondary metabolite gene clusters and the deletion of atfA enhanced the stress responsiveness of additional clusters. Moreover, certain clusters were down-regulated by the stresses tested.
  
  
  CONCLUSIONS
  Our data suggest that the observed co-regulations were most likely consequences of the overlapping physiological effects of the stressors and not of the existence of a general environmental stress response. The function of AtfA in governing various stress responses is much smaller than anticipated and/or other regulators may play a redundant or overlapping role with AtfA. Both stress inducible and stress repressive regulations of secondary metabolism seem to be frequent features in A. nidulans.
authors.affiliation: Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, P.O. Box 63, H-4032, Debrecen, Hungary. emri.tamas@science.unideb.hu.
authors.forename: Tamás
authors.initials: T
authors.lastname: Emri
authors.affiliation: Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, P.O. Box 63, H-4032, Debrecen, Hungary. szarvas.vera@gmail.com.
authors.forename: Vera
authors.initials: V
authors.lastname: Szarvas
authors.affiliation: Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, P.O. Box 63, H-4032, Debrecen, Hungary. orosz.zsoka@gmail.com.
authors.forename: Erzsébet
authors.initials: E
authors.lastname: Orosz
authors.affiliation: Department of Zoology, Faculty of Sciences, Eszterházy Károly College, Eszterházy út 1, H-3300, Eger, Hungary. antalk2@gmail.comp.
authors.forename: Károly
authors.initials: K
authors.lastname: Antal
authors.affiliation: Department of Bacteriology, University of Wisconsin, 1550 Linden Dr, Madison, WI, 53706, USA. heesoo.park@duke.edu.
authors.forename: HeeSoo
authors.initials: H
authors.lastname: Park
authors.affiliation: Department of Pharmaceutical Engineering, Woosuk University, 565-701, Wanju, Republic of Korea. kaphoon@gmail.com.
authors.forename: Kap-Hoon
authors.initials: KH
authors.lastname: Han
authors.affiliation: Department of Bacteriology, University of Wisconsin, 1550 Linden Dr, Madison, WI, 53706, USA. jyu1@wisc.edu.
authors.forename: Jae-Hyuk
authors.initials: JH
authors.lastname: Yu
authors.affiliation: Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, P.O. Box 63, H-4032, Debrecen, Hungary. pocsi.istvan@science.unideb.hu.
authors.forename: István
authors.initials: I
authors.lastname: Pócsi
mesh_terms: D001233:Aspergillus nidulans / Q000235:genetics*; D015536:Down-Regulation / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics; D015966:Gene Expression Regulation, Fungal / Q000235:genetics; D005838:Genotype; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D064210:Secondary Metabolism / Q000235:genetics; D013172:Spores, Fungal / Q000235:genetics; D013312:Stress, Physiological / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics
chemical_list: D005656:Fungal Proteins; D012333:RNA, Messenger; D014157:Transcription Factors