Project description:In Aspergillus nidulans, nitrogen and carbon metabolism are under the control of wide-domain regulatory systems, including nitrogen metabolite repression, carbon catabolite repression. Transcriptomic analysis of the wild type strain grown under different combinations of carbon and nitrogen regimes was performed, to identify differentially regulated genes. Carbon metabolism predominates as the most important regulatory signal but for many genes, both carbon and nitrogen metabolisms coordinate regulation.
Project description:Nitrogen metabolism in Aspergillus nidulans is subject to regulation by the GATA transcription factor AreA which is required for the utilization of a wide range of nitrogen sources other than glutamine or ammonium. The level of AreA activity is regulated by intracellular glutamine levels that vary in response to nitrogen supplementation. For nitrate assimilation, which involves two transporters (CrnA, CrnB), nitrate reductase (NiaD) and nitrite reductase (NiiA), the respective genes are subject to regulation at the level of transcription, including nitrogen metabolite repression mediated by AreA and induction mediated by nitrite or nitrate, mediated by a second transcription factor, NirA. Both transcription factors act synergistically to regulate the expression of all four structural genes when nitrogen is limiting or either nitrate or nitrite is available. In this study we dissect the nitrogen limitation effect mediated by AreA form the nitrate/nitrite specific effect mediated by NirA on the transcriptome level. Keywords: Nitrate/nitrogen limitation response
Project description:Investigation of whole genome gene expression level changes in Aspergillus nidulans OE::rsmA compared to wild-type RDIT9.32 (veA). A twelve array study using total RNA recovered from six separate cultures of Aspergillus nidulans wild-type RDIT9.32 (veA) and six separate cultures of Aspergillus nidulans overexpressing rsmA (restorer of secondary metabolism A), using custom-designed, four-plex arrays. The experiment was divided into two runs. In the first run, three biological replicates each of Aspergillus nidulans wild-type RDIT9.32 (veA) and Aspergillus nidulans carrying a plasmid overexpressing rsmA under the control of the gpdA promoter were assayed. In the second run, three biological replicates each of Aspergillus nidulans wild-type RDIT9.32 (veA) and Aspergillus nidulans overexpressing rsmA at the native locus under the control of the gpdA promoter were assayed.
Project description:Investigation of whole genome gene expression level changes in Aspergillus nidulans AN1599 (PbcR) overexpression mutant, compared to the FGSC A4 wild-type strain. Overexpression of the Zn(II)2Cys6 –type transcription factor, AN1599.4 (PbcR, pimaradiene biosynthetic cluster regulator), activates a secondary metabolite gene cluster in Aspergillus nidulans. Activation of the pathway in Aspergillus nidulans lead to a production of ent-pimara-8(14),15-diene.
Project description:Aspergillus nidulans is a model organism for aspergilli, an important group of filamentous fungi that encompasses human and plant pathogens, as well as industrial cell factories. Aspergilli have a highly diversified metabolism and both in connection with their biotechnological application as well as their interaction with other cells (humans or plants), it is valuable to understand how their metabolism is regulated. We therefore performed genome-wide transcription analysis of A. nidulans grown on three different carbon sources (glucose, glycerol, and ethanol) with the objective to identify global regulatory structures. We furthermore reconstructed the complete metabolic network of this organism, and this resulted in linking of 666 genes with metabolic functions, as well as assigning metabolic roles to 472 genes that had not been annotated earlier. Through combinations of the reconstructed metabolic network and the transcription data, we identified subnetwork structures that pointed to coordinated regulation of genes involved in many different parts of the metabolism. Keywords: carbon sources, metabolism, comparative genomics
Project description:Gene expression analysis of four different treatments of Aspergillus nidulans. reference line (A.nidulans), line A (A.nidulans + Streptomyces rapamycinicus), line B (A.nidulans + orsellinic acid), line C (A.nidulans + lecanoric acid)
Project description:The basidiomycete Ustilago maydis is the causal agent of corn smut disease and induces tumor formation during biotrophic growth in its host plant maize. The Usilago maydis genome harbors a homolog to the GATA transcription factors Nit2 and AreA that act as global regulators of nitrogen catabolite repression in filamentous model fungi Neurospora crassa and Aspergillus nidulans, respectively. We aimed at resolving the role of the Ustilago maydis Nit2 homolog for the utilization of complex nitrogen sources and pathogenicity.
Project description:Although tyrosol is a quorum-sensing molecule of Candida species, it has antifungal activity at supraphysiological concentrations. Here, we studied the effect of tyrosol on the physiology and genome-wide transcription of Aspergillus nidulans to gain insight into the background of the antifungal activity of this compound. Tyrosol efficiently reduced germination of conidia and the growth on various carbon sources at a concentration of 35 mM. The growth inhibition was fungistatic rather than fungicide on glucose and was accompanied with downregulation of 2199 genes related to e.g. mitotic cell cycle, glycolysis, nitrate and sulphate assimilation, chitin biosynthesis, and upregulation of 2250 genes involved in e.g. lipid catabolism, amino acid degradation and lactose utilization. Tyrosol treatment also upregulated genes encoding glutathione-S-transferases (GSTs), increased specific GST activities and the glutathione (GSH) content of the cells, suggesting that A. nidulans can detoxify tyrosol in a GSH-dependent manner even though this process was weak. Tyrosol did not induce oxidative stress in this species, but upregulated “response to nutrient levels”, “regulation of nitrogen utilization”, “carbon catabolite activation of transcription” and “autophagy” genes. Tyrosol may have disturbed the regulation and orchestration of cellular metabolism, leading to impaired use of nutrients, which resulted in growth reduction.