A p53-like transcription factor similar to Ndt80 controls the response to nutrient stress in the filamentous fungus, Aspergillus nidulans

Katz, Margaret; Braunberger, Kathryn; Yi, Gauncai; Cooper, Sarah; Nonhebel, Heather M.; Gondro, Cedric

doi:10.3410/f1000research.2-72.v1

Cited by 6 publications

(20 citation statements)

References 4 publications

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“…In line with this, enrichment of almost all of these GO-terms was also observed in the 5 days glucose culture where glucose is depleted and increased transcription of genes linked to fatty acid metabolism in response to carbon starvation has been reported for Aspergilli [16,55] as well as in other fungi [56,57]. A role for carbon starvation in induction of plant polysaccharide degradative enzymes was previously established in A. niger [34,38], A. nidulans [36,37,58] and N. crassa [28,59], which involved low-level upregulation of a subset of genes encoding CAZymes active on plant polysaccharides, the 'scouting enzymes' . Besides generating energy for cell maintenance, fatty acid metabolism may generate energy required for production of these scouting enzymes or assist in establishing fungal colonisation of lignocellulose.…”

Section: Initial Response To Lignocellulose Involved Increased Fungalsupporting

confidence: 73%

Succession of physiological stages hallmarks the transcriptomic response of the fungus Aspergillus niger to lignocellulose

Munster

Daly

Blythe

et al. 2020

Biotechnol Biofuels

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Background: Understanding how fungi degrade lignocellulose is a cornerstone of improving renewables-based biotechnology, in particular for the production of hydrolytic enzymes. Considerable progress has been made in investigating fungal degradation during time-points where CAZyme expression peaks. However, a robust understanding of the fungal survival strategies over its life time on lignocellulose is thereby missed. Here we aimed to uncover the physiological responses of the biotechnological workhorse and enzyme producer Aspergillus niger over its life time to six substrates important for biofuel production. Results: We analysed the response of A. niger to the feedstock Miscanthus and compared it with our previous study on wheat straw, alone or in combination with hydrothermal or ionic liquid feedstock pretreatments. Conserved (substrate-independent) metabolic responses as well as those affected by pretreatment and feedstock were identified via multivariate analysis of genome-wide transcriptomics combined with targeted transcript and protein analyses and mapping to a metabolic model. Initial exposure to all substrates increased fatty acid beta-oxidation and lipid metabolism transcripts. In a strain carrying a deletion of the ortholog of the Aspergillus nidulans fatty acid beta-oxidation transcriptional regulator farA, there was a reduction in expression of selected lignocellulose degradative CAZymeencoding genes suggesting that beta-oxidation contributes to adaptation to lignocellulose. Mannan degradation expression was wheat straw feedstock-dependent and pectin degradation was higher on the untreated substrates. In the later life stages, known and novel secondary metabolite gene clusters were activated, which are of high interest due to their potential to synthesize bioactive compounds. Conclusion: In this study, which includes the first transcriptional response of Aspergilli to Miscanthus, we highlighted that life time as well as substrate composition and structure (via variations in pretreatment and feedstock) influence the fungal responses to lignocellulose. We also demonstrated that the fungal response contains physiological stages that are conserved across substrates and are typically found outside of the conditions with high CAZyme expression, as exemplified by the stages that are dominated by lipid and secondary metabolism.

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Section: Initial Response To Lignocellulose Involved Increased Fungalsupporting

confidence: 73%

Succession of physiological stages hallmarks the transcriptomic response of the fungus Aspergillus niger to lignocellulose

Munster

Daly

Blythe

et al. 2020

Biotechnol Biofuels

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“…While in S. cerevisiae Ndt80 is primarily involved in the regulation of meiosis, the Ndt80‐like proteins in N. crassa (VIB‐1, FSD‐1) have other functions. Mutations in fsd‐1 affected the timing and development of female reproductive structures and ascospore maturation (Hutchison and Glass, ), and the A. nidulans homolog, ndtA , is apparently required for sexual reproduction (Katz et al ., ). Further, VIB‐1 is involved in the regulation of vegetative incompatibility and programmed cell death.…”

Section: Resultsmentioning

confidence: 97%

“…A), a number of observations apparently unrelated to GlcNAc were published. An xprG gain‐of‐function mutant ( xprG1 ) was described that overproduces extracellular proteases under starvation conditions (Katz et al ., 2006; 2013). xprG loss‐of‐function mutants show reduced extracellular protease levels under both carbon and nitrogen starvation conditions.…”

Section: Resultsmentioning

confidence: 99%

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The N‐acetylglucosamine catabolic gene cluster in Trichoderma reesei is controlled by the Ndt80‐like transcription factor RON1

Kappel

Gaderer

Flipphi

et al. 2015

Molecular Microbiology

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SummaryChitin is an important structural constituent of fungal cell walls composed of N‐acetylglucosamine (GlcNAc) monosaccharides, but catabolism of GlcNAc has not been studied in filamentous fungi so far. In the yeast C andida albicans, the genes encoding the three enzymes responsible for stepwise conversion of GlcNAc to fructose‐6‐phosphate are clustered. In this work, we analysed GlcNAc catabolism in ascomycete filamentous fungi and found that the respective genes are also clustered in these fungi. In contrast to C . albicans, the cluster often contains a gene for an Ndt80‐like transcription factor, which we named RON1 (regulator of N‐acetylglucosamine catabolism 1). Further, a gene for a glycoside hydrolase 3 protein related to bacterial N‐acetylglucosaminidases can be found in the GlcNAc gene cluster in filamentous fungi. Functional analysis in T richoderma reesei showed that the transcription factor RON1 is a key activator of the GlcNAc gene cluster and essential for GlcNAc catabolism. Furthermore, we present an evolutionary analysis of Ndt80‐like proteins in Ascomycota. All GlcNAc cluster genes, as well as the GlcNAc transporter gene ngt1, and an additional transcriptional regulator gene, csp2, encoding the homolog of N eurospora crassa CSP2/GRHL, were functionally characterised by gene expression analysis and phenotypic characterisation of knockout strains in T . reesei.

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“…mcrA regulates several SM BGCs and this implies that it is involved in the regulation of transcription of many genes involved in SM biosynthesis. Secondary metabolism is intimately connected to a number of other processes in the cell, however, such as primary metabolism and development (Bayram and Braus, ; Bayram et al ., ; Katz et al ., ; de Souza et al ., ; Brakhage, ; Garzia et al ., ). We wished to determine, therefore, if the effects of mcrA on gene expression extended beyond genes involved in secondary metabolism.…”

Section: Resultsmentioning

confidence: 99%

Discovery of McrA, a master regulator of Aspergillus secondary metabolism

Oakley

Ahuja

Sun

et al. 2016

Molecular Microbiology

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Summary Fungal secondary metabolites (SMs) are extremely important in medicine and agriculture, but regulation of their biosynthesis is incompletely understood. We have developed a genetic screen in Aspergillus nidulans for negative regulators of fungal SM gene clusters and we have used this screen to isolate mutations that upregulate transcription of the non-ribosomal peptide synthetase gene required for nidulanin A biosynthesis. Several of these mutations are allelic and we have identified the mutant gene by genome sequencing. The gene, which we designate mcrA, is conserved but uncharacterized, and it encodes a putative transcription factor. Metabolite profiles of mcrA deletant, mcrA overexpressing, and parental strains reveal that mcrA regulates at least ten SM gene clusters. Deletion of mcrA stimulates SM production even in strains carrying a deletion of the SM regulator laeA, and deletion of mcrA homologs in Aspergillus terreus and Penicillum canescens alters the secondary metabolite profile of these organisms. Deleting mcrA in a genetic dereplication strain has allowed us to discover two novel compounds as well as an antibiotic not known to be produced by A. nidulans. Deletion of mcrA upregulates transcription of hundreds of genes including many that are involved in secondary metabolism, while downregulating a smaller number of genes.

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A p53-like transcription factor similar to Ndt80 controls the response to nutrient stress in the filamentous fungus, Aspergillus nidulans

Cited by 6 publications

References 4 publications

Succession of physiological stages hallmarks the transcriptomic response of the fungus Aspergillus niger to lignocellulose

Succession of physiological stages hallmarks the transcriptomic response of the fungus Aspergillus niger to lignocellulose

The N‐acetylglucosamine catabolic gene cluster in Trichoderma reesei is controlled by the Ndt80‐like transcription factor RON1

Discovery of McrA, a master regulator of Aspergillus secondary metabolism

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