Dataset Information

The Aspergillus fumigatus StuA protein governs the up-regulation of a discrete transcriptional program during the acquisition of developmental competence.

ABSTRACT: Members of the Asm1p, Phd1p, Sok2p, Efg1p, and StuAp (APSES) family of fungal proteins regulate morphogenesis and virulence in ascomycetes. We cloned the Aspergillus fumigatus APSES gene encoding StuAp and demonstrated that stuA transcription is markedly up-regulated after the acquisition of developmental competence. A. fumigatus DeltastuA mutants were impaired in their ability to undergo asexual reproduction. Conidiophore morphology was markedly abnormal, and only small numbers of dysmorphic conidia were produced, which exhibited precocious germination. Whole genome transcriptional analysis during the onset of developmental competence was performed and identified a subset of developmentally regulated genes that were stuA dependent, including a cluster of putative secondary metabolite biosynthesis genes, genes encoding proteins implicated in the regulation of morphogenesis, and genes encoding allergens and other antigenic proteins. Additionally, hyphae of the DeltastuA mutant displayed reduced expression of the catalase gene CAT1 and were hypersusceptible to hydrogen peroxide.

SUBMITTER: Sheppard DC

PROVIDER: S-EPMC1289428 | biostudies-literature | 2005 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

The Aspergillus fumigatus StuA protein governs the up-regulation of a discrete transcriptional program during the acquisition of developmental competence.

Sheppard Donald C DC Doedt Thomas T Chiang Lisa Y LY Kim H Stanley HS Chen Dan D Nierman William C WC Filler Scott G SG

Molecular biology of the cell 20051005 12

Members of the Asm1p, Phd1p, Sok2p, Efg1p, and StuAp (APSES) family of fungal proteins regulate morphogenesis and virulence in ascomycetes. We cloned the Aspergillus fumigatus APSES gene encoding StuAp and demonstrated that stuA transcription is markedly up-regulated after the acquisition of developmental competence. A. fumigatus DeltastuA mutants were impaired in their ability to undergo asexual reproduction. Conidiophore morphology was markedly abnormal, and only small numbers of dysmorphic co ...[more]

PMID: 16207816

Similar Datasets

Project description:The APSES transcription factor (TF) in Aspergillus species is known to govern diverse cellular processes, including growth, development, and secondary metabolism. Here, we investigated functions of the rgdA gene (Afu3g13920) encoding a putative APSES TF in the opportunistic human-pathogenic fungus Aspergillus fumigatus The rgdA deletion resulted in significantly decreased hyphal growth and asexual sporulation. Consistently, transcript levels of the key asexual developmental regulators abaA, brlA, and wetA were decreased in the ?rgdA mutant compared to those in the wild type (WT). Moreover, ?rgdA resulted in reduced spore germination rates and elevated transcript levels of genes associated with conidium dormancy. The conidial cell wall hydrophobicity and architecture were changed, and levels of the RodA protein were decreased in the ?rgdA mutant. Comparative transcriptomic analyses revealed that the ?rgdA mutant showed higher mRNA levels of gliotoxin (GT)-biosynthetic genes and GT production. While the ?rgdA mutant exhibited elevated production of GT, ?rgdA strains showed reduced virulence in the mouse model. In addition, mRNA levels of genes associated with the cyclic AMP (cAMP)-protein kinase A (PKA) signaling pathway and the SakA mitogen-activated protein (MAP) kinase pathway were increased in the ?rgdA mutant. In summary, RgdA plays multiple roles in governing growth, development, GT production, and virulence which may involve attenuation of PKA and SakA signaling.IMPORTANCE Immunocompromised patients are susceptible to infections with the opportunistic human-pathogenic fungus Aspergillus fumigatus This fungus causes systemic infections such as invasive aspergillosis (IA), which is one of the most life-threatening fungal diseases. To control this serious disease, it is critical to identify new antifungal drug targets. In fungi, the transcriptional regulatory proteins of the APSES family play crucial roles in controlling various biological processes, including mating, asexual sporulation and dimorphic growth, and virulence traits. This study found that a putative APSES transcription factor, RgdA, regulates normal growth, asexual development, conidium germination, spore wall architecture and hydrophobicity, toxin production, and virulence in A. fumigatus Better understanding the molecular mechanisms of RgdA in human-pathogenic fungi may reveal a novel antifungal target for future drug development.

Project description:We examined the antifungal activity of artemisinin against Aspergillus fumigatus (A. fumigatus), a pathogenic filamentous fungus responsible for allergic and invasive aspergillosis in humans and analyzed transcript profiles of the fungus on exposure to Artemisinin. A. fumigatus spores were cultured for 48 h and then treated with artemisinin (at MIC50 concentration) or solvent control (DMSO) for 3 h to study its transcriptomic profiles. Total RNA (7 M-BM-5g) from A. fumigatus treated with solvent control (DMSO) or artemisinin was reverse transcribed separately using fluorescein-labeled dCTP or biotin-labeled dCTP from Micromax TSA labeling kit (Cy3 or Cy5 dyes are differentially deposited to these labeled cDNAs, post-hybridization, using tyramide signal amplification (TSA) protocol). Labeled cDNAs from test and control sample were mixed in equal amount and hybridized to microarray slide(s). After hybridization, the slides were processed as per the protocol of the Micromax TSA labeling kit and scanned in both the Cy3 and the Cy5 channels with a model 4200 Axon Instruments scanner with a 10-M-BM-5m resolution. Each of the signals was converted into a resolution of 16 bits per pixel. A dye swap experiment with a biological replicate was performed to ensure the reproducibility of each gene expression pattern.TIFF images were analyzed using GenePix Pro 6.0 software. The signal intensity value of each spot was reduced by the local background level for each spot. Diagnosis and normalization of microarray data (DNMAD) program was used for print-tip loess normalization of microarray data and for merging the data from dye-swap experiments . M-values obtained from this program were converted to log ratio (test/reference) and fold modulation. Genes having less than 3 spots in 2 dye swap slides were discarded and only those having their all fold change values (from 3 or 4 replicates in 2 slides; as each target is spotted twice on the slide) within a coefficient of variation M-BM-1 0.5 were used for analysis. Gene expression ratios of M-bM-^IM-%2 (fold upregulation or downregulation) in both replicates (dye swap) were considered to be differentially expressed genes.

Dataset Information

The Aspergillus fumigatus StuA protein governs the up-regulation of a discrete transcriptional program during the acquisition of developmental competence.

Publications

The Aspergillus fumigatus StuA protein governs the up-regulation of a discrete transcriptional program during the acquisition of developmental competence.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets