Molecular Genetics and Genomics

, Volume 283, Issue 3, pp 289–303

AtfA bZIP-type transcription factor regulates oxidative and osmotic stress responses in Aspergillus nidulans

  • Anita Balázs
  • Imre Pócsi
  • Zsuzsanna Hamari
  • Éva Leiter
  • Tamás Emri
  • Márton Miskei
  • Judit Oláh
  • Viktória Tóth
  • Nikoletta Hegedűs
  • Rolf A. Prade
  • Mónika Molnár
  • István Pócsi
Original Paper

DOI: 10.1007/s00438-010-0513-z

Cite this article as:
Balázs, A., Pócsi, I., Hamari, Z. et al. Mol Genet Genomics (2010) 283: 289. doi:10.1007/s00438-010-0513-z

Abstract

The aim of the study was to demonstrate that the bZIP-type transcription factor AtfA regulates different types of stress responses in Aspergillus nidulans similarly to Atf1, the orthologous ‘all-purpose’ transcription factor of Schizosaccharomyces pombe. Heterologous expression of atfA in a S. pombe Δatf1 mutant restored the osmotic stress tolerance of fission yeast in surface cultures to the same level as recorded in complementation studies with the atf1 gene, and a partial complementation of the osmotic and oxidative-stress-sensitive phenotypes was also achieved in submerged cultures. AtfA is therefore a true functional ortholog of fission yeast’s Atf1. As demonstrated by RT-PCR experiments, elements of both oxidative (e.g. catalase B) and osmotic (e.g. glycerol-3-phosphate dehydrogenase B) stress defense systems were transcriptionally regulated by AtfA in a stress-type-specific manner. Deletion of atfA resulted in oxidative-stress-sensitive phenotypes while the high-osmolarity stress sensitivity of the fungus was not affected significantly. In A. nidulans, the glutathione/glutathione disulfide redox status of the cells as well as apoptotic cell death and autolysis seemed to be controlled by regulatory elements other than AtfA. In conclusion, the orchestrations of stress responses in the aspergilli and in fission yeast share several common features, but further studies are needed to answer the important question of whether a fission yeast-like core environmental stress response also operates in the euascomycete genus Aspergillus.

Keywords

Stress signalingOxidative stressOsmotic stressApoptosisAutolysisAuxotrophyCESR

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Anita Balázs
    • 1
  • Imre Pócsi
    • 1
  • Zsuzsanna Hamari
    • 2
  • Éva Leiter
    • 1
  • Tamás Emri
    • 1
  • Márton Miskei
    • 3
  • Judit Oláh
    • 3
  • Viktória Tóth
    • 1
  • Nikoletta Hegedűs
    • 1
  • Rolf A. Prade
    • 4
  • Mónika Molnár
    • 1
  • István Pócsi
    • 1
  1. 1.Department of Microbial Biotechnology and Cell Biology, Faculty of Science and TechnologyUniversity of DebrecenDebrecenHungary
  2. 2.Department of Microbiology, Faculty of Science and InformaticsUniversity of SzegedSzegedHungary
  3. 3.Department of Horticulture and Plant Biotechnology, Faculty of Agricultural ScienceUniversity of DebrecenDebrecenHungary
  4. 4.Department of Microbiology and Molecular GeneticsOklahoma State UniversityStillwaterUSA