Deletion and overexpression of the Aspergillus nidulans GATA factor AreB reveals unexpected pleiotropy.
The Aspergillus nidulans transcription factor AreA is a key regulator of nitrogen metabolic gene expression. AreA contains a C-terminal GATA zinc finger DNA-binding domain and activates expression of genes necessary for nitrogen acquisition. Previous studies identified AreB as a potential negative regulator of nitrogen catabolism showing similarity with Penicillium chrysogenum NreB and Neurospora crassa ASD4. The areB gene encodes multiple products containing an N-terminal GATA zinc finger and a leucine zipper motif. We deleted the areB gene and now show that AreB negatively regulates AreA-dependent nitrogen catabolic gene expression under nitrogen-limiting or nitrogen-starvation conditions. AreB also acts pleiotropically, with functions in growth, conidial germination and asexual development, though not in sexual development. AreB overexpression results in severe growth inhibition, aberrant cell morphology and reduced AreA-dependent gene expression. Deletion of either the DNA-binding domain or the leucine zipper domain results in loss of both nitrogen and developmental phenotypes.
Wong
Koon Ho
KH
Department of Genetics, The University of Melbourne, Parkville 3010, Australia.
Hynes
Michael J
MJ
Department of Genetics, The University of Melbourne, Parkville 3010, Australia.
Todd
Richard B
RB
Department of Plant Pathology, Kansas State University, 4024 Throckmorton Hall, Manhattan, KS 66506-5502 USA.|Department of Genetics, The University of Melbourne, Parkville 3010, Australia.
Davis
Meryl A
MA
Department of Genetics, The University of Melbourne, Parkville 3010, Australia.
D000595:Amino Acid Sequence; D001233:Aspergillus nidulans / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D004271:DNA, Fungal / Q000235:genetics; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D050980:GATA Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D017353:Gene Deletion; D015870:Gene Expression; D005800:Genes, Fungal; D016350:Leucine Zippers; D008969:Molecular Sequence Data; D009154:Mutation; D009584:Nitrogen / Q000378:metabolism; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
C079728:AreA protein, Aspergillus nidulans; C434269:AreB protein, Aspergillus nidulans; D017931:DNA Primers; D004271:DNA, Fungal; D005656:Fungal Proteins; D050980:GATA Transcription Factors; D014157:Transcription Factors; D009584:Nitrogen