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 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: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: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.
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 M-bM-^@M-^Stype 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. 12x135K array of two separate cultures of FGSC A4 and two separate cultures of oe:AN1599(PbcR) with three separate RNA extractions from each culture. Each 135K array measures expression level of 10,546 genes with 6 probes/transcript. In addition, the array format contains tiling probes for 36 longer transcripts. All probes are in duplicates, giving the total number of 137,562 probes per array.
Project description:Transcriptional profiling of A. nidulans comparing starvation for 0 (reference), 12 and 24 h. The main objective was to identify genes specifically regulated during starvation by atmA and xprG. The results of the experiment were further validated by real-time PCR. Experimental procedure: Three A. nidulans strains were used in this study: WT, delta atmA and delta xprG. Strains were grown on minimal medium for 24 h (0 h starvation reference), then exposed to 12 and 24 h starvation. atmA: ATM, Ataxia-Telangiectasia mutated; Malavazi, I., Savoldi, M., Da Silva Ferreira, M. E., Soriani, F. M., Bonato, P. S., De Souza Goldman, M. H. and Goldman, G. H. (2007), Transcriptome analysis of the Aspergillus nidulans AtmA (ATM, Ataxia-Telangiectasia mutated) null mutant. Molecular Microbiology, 66: 74-99 (PMID 17880424). xprG: extracellular protease; Margaret E. Katz, Karen-Ann Gray, Brian F. Cheetham, (2006) The Aspergillus nidulans xprG (phoG) gene encodes a putative transcriptional activator involved in the response to nutrient limitation, Fungal Genetics and Biology, 43, 190-199 (PMID 16464624).
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)