Two putative Zn(II)2Cys6 transcription factors, RosA (repressor of sexual development) and NosA (no sexual development) trigger early developmental decisions in the filamentous fungus Aspergillus nidulans.

Kay Vienken1, Reinhard Fischer2.

Author address: 

1Biochemistry; Max-Planck-Institute for terrestrial Microbiology; Marburg; 2Applied Microbiology, TU Karlsruhe; Germany


Morphologic differentiation processes such as spore production in fungi are largely controlled by stage-specific expression of regulatory proteins. We have analyzed two putative Zn(II)2Cys6 transcription factors in the filamentous fungus A. nidulans. One gene, rosA, encodes a 713 amino acid long protein transiently expressed during asexual rather than sexual development. Expression was also induced after carbon starvation. Deletion of the gene caused the fungus to initiate sexual spore production under non-appropriate conditions, such as carbon-starvation or in liquid culture. Subcellular localization of a RosA-GFP fusion protein suggested that shuttling of the factor between the cytoplasm and the nucleus may be important for the function. In summary, RosA is involved in the transduction of environmental conditions into developmental decisions. The second regulator, NosA, is in contrast to the negative regulator RosA, essential to induce sexual development. The expression of the gene appeared to be constitutive suggesting posttranscriptional regulation of NosA activity. To identify putative target genes for the two important regulators we performed DIGE-2D-gel electrophoresis with subsequent peptide mass fingerprinting for protein identification.

abstract No: 


Full conference title: 

23rd Fungal Genetics Conference
    • Fungal Genetics Conference 23rd (2002)