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.
Eukaryot Cell
; 8(1): 104-15, 2009 Jan.
Article
en En
| MEDLINE
| ID: mdl-19028996
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.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Aspergillus fumigatus
/
Factores de Transcripción
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Transcripción Genética
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Proteínas Fúngicas
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Regulación del Desarrollo de la Expresión Génica
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Nitrógeno
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Eukaryot Cell
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2009
Tipo del documento:
Article
País de afiliación:
Canadá
Pais de publicación:
Estados Unidos