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Transcriptional profiling identifies a role for BrlA in the response to nitrogen depletion and for StuA in the regulation of secondary metabolite clusters in Aspergillus fumigatus.
- Source :
-
Eukaryotic cell [Eukaryot Cell] 2009 Jan; Vol. 8 (1), pp. 104-15. Date of Electronic Publication: 2008 Nov 21. - Publication Year :
- 2009
-
Abstract
- Conidiation (asexual sporulation) is a key developmental process in filamentous fungi. We examined the gene regulatory roles of the Aspergillus fumigatus developmental transcription factors StuAp and BrlAp during conidiation. Conidiation was completely abrogated in an A. fumigatus DeltabrlA mutant and was severely impaired in a DeltastuA mutant. We determined the full genome conidiation transcriptomes of wild-type and DeltabrlA and DeltastuA mutant A. fumigatus and found that BrlAp and StuAp governed overlapping but distinct transcriptional programs. Six secondary metabolite biosynthetic clusters were found to be regulated by StuAp, while only one cluster exhibited BrlAp-dependent expression. The DeltabrlA mutant, but not the DeltastuA mutant, had impaired downregulation of genes encoding ribosomal proteins under nitrogen-limiting, but not carbon-limiting, conditions. Interestingly, inhibition of the target of rapamycin (TOR) pathway also caused downregulation of ribosomal protein genes in both the wild-type strain and the DeltabrlA mutant. Downregulation of these genes by TOR inhibition was associated with conidiation in the wild-type strain but not in the DeltabrlA mutant. Therefore, BrlAp-mediated repression of ribosomal protein gene expression is not downstream of the TOR pathway. Furthermore, inhibition of ribosomal protein gene expression is not sufficient to induce conidiation in the absence of BrlAp.
- Subjects :
- Aspergillus fumigatus cytology
Aspergillus fumigatus growth & development
Aspergillus fumigatus metabolism
Fungal Proteins genetics
Gene Expression Regulation, Fungal
Mutation
Oligonucleotide Array Sequence Analysis
Ribosomes genetics
Ribosomes metabolism
Signal Transduction
Spores, Fungal genetics
Spores, Fungal growth & development
Spores, Fungal metabolism
Transcription Factors genetics
Aspergillus fumigatus genetics
Fungal Proteins metabolism
Gene Expression Regulation, Developmental
Nitrogen metabolism
Transcription Factors metabolism
Transcription, Genetic
Subjects
Details
- Language :
- English
- ISSN :
- 1535-9786
- Volume :
- 8
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Eukaryotic cell
- Publication Type :
- Academic Journal
- Accession number :
- 19028996
- Full Text :
- https://doi.org/10.1128/EC.00265-08