The Rim15p homolog RimO mediates starvation response and is required for secondary metabolite production in Aspergillus nidulans
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA765369 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Depending on the prevailing environmental, developmental and nutritional conditions Aspergillus nidulans produces different combinations of secondary metabolites (SMs). To activate the biosynthetic gene cluster (BGC) for a given SM global, chromatin-based de-repression must be integrated with pathway-specific induction signals. Here we describe a new global regulator affecting the set of starvation-induced SMs. We found a hitherto uncharacterized putative PAS-domain containing kinase to be upregulated in SM-producing cultures. The predicted protein is highly similar to yeast Rim15 which transmits nutritional and stress signals to downstream effectors involved in chromatin regulation, stress and starvation response. The putative kinase – termed RimO – is required for the transcription of a number of starvation-induced SMs including sterigmatocystin (ST). RimO regulates the pathway-specific transcription factor AflR both at the transcriptional and post-translational level. In the absence of RimO aflR is barely transcribed under SM conditions and the protein is not retained in the nucleus. Genome-wide transcriptional profiling showed that cells lacking rimO fail to correctly respond to carbon and nitrogen starvation and continue to transcribe genes of the basic metabolism to a high level. Conversely, overexpression of the kinase made cells largely insensitive to glucose repression and led to overproduction of several secondary metabolites. We propose a model that positions RimO downstream of PKA being necessary to transmit the starvation signal to downstream targets, including chromatin and transcriptional regulators of SM gene clusters. Additionally, it may also regulate signaling modules required for recognizing the starvation response.
2022-03-01 | GSE184618 | GEO
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).
2012-12-07 | E-GEOD-42732 | biostudies-arrayexpress
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.
2012-12-07 | GSE42732 | GEO
Project description:The cell wall is a structure involved in important stages of fungal growth and morphogenesis. Several studies in the literature have shown how perturbations at the cell wall-level trigger dramatic effects on growth (e.g. Horiuchi, 2009). Despite the importance of fungal cell walls and despite the great advances made in the field, there are still missing pieces in our understanding of cell wall dynamics in filamentous fungi. Some cell wall biosynthetic genes, for example, are still uncharacterized (for a detailed inventory of Aspergillus nidulans cell wall-related genes, see de Groot et al., 2009). The chief polysaccharides in the cell wall of the model organism A. nidulans are β-glucans (β-1,3-, β-(1,3;1,4)- and β-1,6-glucans), chitin and α-1,3-glucans. While much is known about the chitin and α-1,3-glucan biosynthetic genes in A. nidulans (Horiuchi et al., 1999; Fujiwara et al., 2000; Ichinomiya et al., 2002 and 2005; Takeshita et al., 2006; Yoshimi et al., 2013), no characterization is yet available for the celA gene (ANIA_08444) encoding a putative mixed-linkage glucan synthase (de Groot et al., 2009). Recently, a study on A. fumigatus has characterized Tft1, an enzyme shown to be responsible for the production of β-(1,3;1,4)-glucans in this organism (Samar et al., 2015). Deletion of Tft1 causes no obvious phenotype in A. fumigatus and a modest increase in virulence. To characterize the role of β-(1,3;1,4)-glucans in the growth and development of filamentous fungi, we here sought to provide transcriptomics data of an A. nidulans strain showing reduced expression of the gene encoding the putative mixed linkage glucan synthase celA.
2017-07-26 | GSE94110 | GEO
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.
2012-04-16 | GSE32954 | GEO
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
2009-01-01 | GSE10475 | GEO
Project description:Glutathione (GSH) is an abundant and widely distributed antioxidant in fungi. Hence, understanding cellular GSH metabolism is of vital importance to deciphering redox regulation in these microorganisms. In this study, we generated dugB (AN1879), dugC (AN1092), and dugB dugC double deletion mutants which display disruption of the GSH degradation pathway in Aspergillus nidulans. Deletion of dugB, dugC or both resulted in a moderate increase in GSH content under growing conditions and substantially slowed down the depletion of GSH pools under carbon starvation. Inactivation of dug genes caused reduced accumulation of reactive oxygen species, decreased autolytic cell wall degradation and extracellular enzyme production, increased sterigmatocystin formation but decreased viability in starving cultures. Changes in the transcriptomes suggested that enzyme secretions were controlled at post transcriptional level. In contrast, secondary metabolite production was also regulated at the level of mRNA abundance. Based on these findings, we suggest that GSH connects starvation and redox regulation to each other: A. nidulans cells utilize GSH as stored carbon source during starvation. The reduction of GSH contents of cells alters the redox state activating regulatory pathways responsible for carbon starvation stress responses. Under glucose rich conditions, inactivation of dug genes reduced conidia production of surface cultures, disturbed sexual development and down-regulated the transcription of genes encoding MAP kinase pathway proteins (e.g. steC, sskB, pbsA, hogA, mkkA) or proteins involved in the regulation of conidiogenesis or sexual differentiation (e.g. flbA,C,E, nosA, rosA, nsdC,D). These finding indicates that the authority of redox regulation goes far beyond the protection against redox stress; it affects development, stress responses (other than redox stress) and secondary metabolism as well.
2021-03-02 | GSE151461 | GEO
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.
2012-04-15 | E-GEOD-32954 | biostudies-arrayexpress
Project description:Transcriptional profiling of Aspergillus nidulans comparing control (growing on glucose) and carbon starving cultures.
2020-04-08 | GSE42610 | GEO
Project description:Phytochrome-dependent light signaling has been studied in several fungi. In Aspergillus nidulans light-stimulated phytochrome activates the HOG signaling pathway and thereby controls the expression of a large number of genes, many of which are related to stress responses. In a genome-wide expression analysis in A. nidulans we found that phytochrome, fphA, is under strict expression control of the central regulator of the sulfur-starvation response, MetR. This transcriptional regulator is required for the expression of genes involved in inorganic sulfur assimilation. In the presence of organic sulfur, MetR is probably ubiquitinated and possibly degraded and the transcription of sulfur-assimilation genes, e.g. sulfate permease, is turned off. The expression analysis described here revealed, however, that MetR additionally controls the expression of hundreds of genes, many of which are required for secondary metabolite production. We also show that metR mutation phenocopies fphA deletion, and five other histidine-hybrid kinases are down-regulated in the metR1 mutant. Furthermore, we show that light and phytochrome regulate the expression of at least three carbon-sulfur hydrolases. This work is a further step towards understanding the interplay between light sensing and metabolic pathways.
2020-12-01 | GSE156068 | GEO