Browse
Submit Data
Databases
API
Help

Dataset Information

12 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Co-option of an extracellular protease for transcriptional control of nutrient degradation in the fungus Aspergillus nidulans.

ABSTRACT: Nutrient acquisition is essential for all organisms. Fungi regulate their metabolism according to environmental nutrient availability through elaborate transcription regulatory programs. In filamentous fungi, a highly conserved GATA transcription factor AreA and its co-repressor NmrA govern expression of genes involved in extracellular breakdown, uptake, and metabolism of nitrogen nutrients. Here, we show that the Aspergillus nidulans PnmB protease is a moonlighting protein with extracellular and intracellular functions for nitrogen acquisition and metabolism. PnmB serves not only as a secreted protease to degrade extracellular nutrients, but also as an intracellular protease to control the turnover of the co-repressor NmrA, accelerating AreA transcriptional activation upon nitrogen starvation. PnmB expression is controlled by AreA, which activates a positive feedback regulatory loop. Hence, we uncover a regulatory mechanism in the well-established controls determining the response to nitrogen starvation, revealing functional evolution of a protease gene for transcriptional regulation and extracellular nutrient breakdown.

SUBMITTER: Li A

PROVIDER: S-EPMC8683493 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Distinct septin heteropolymers co-exist during multicellular development in the filamentous fungus Aspergillus nidulans.

Project description:Septins are important components of the cytoskeleton that are highly conserved in eukaryotes and play major roles in cytokinesis, patterning, and many developmental processes. Septins form heteropolymers which assemble into higher-order structures including rings, filaments, and gauzes. In contrast to actin filaments and microtubules, the molecular mechanism by which septins assemble is not well-understood. Here, we report that in the filamentous fungus Aspergillus nidulans, four core septins form heteropolymeric complexes. AspE, a fifth septin lacking in unicellular yeasts, interacts with only one of the core septins, and only during multicellular growth. AspE is required for proper localization of three of the core septins, and requires this same subset of core septins for its own unique cortical localization. The ΔaspE mutant lacks developmentally-specific septin higher-order structures and shows reduced spore production and slow growth with low temperatures and osmotic stress. Our results show that at least two distinct septin heteropolymer populations co-exist in A. nidulans, and that while AspE is not a subunit of either heteropolymer, it is required for assembly of septin higher-order structures found in multicellular development.

| S-EPMC3963935 | biostudies-literature

Suberin degradation by Aspergillus nidulans

Project description:The study aims essentially at the characterisation of suberin degradation mechanisms by Aspergillus nidulans, at a fundamental level. Suberin is an important protective barrier in plant, thus the study of its biodegradation significantly impacts on phytopatology. In addition, fungal suberin degrading enzymes might provide important insights to develop new waste management, bioremediation and biodeterioration prevention strategies.

2014-07-31 | GSE54427 | GEO

Transcriptional control of gluconeogenesis in Aspergillus nidulans.

Project description:Aspergillus nidulans can utilize carbon sources that result in the production of TCA cycle intermediates, thereby requiring gluconeogenesis. We have cloned the acuG gene encoding fructose-1,6 bisphosphatase and found that expression of this gene is regulated by carbon catabolite repression as well as by induction by a TCA cycle intermediate similar to the induction of the previously studied acuF gene encoding phosphoenolpyruvate carboxykinase. The acuN356 mutation results in loss of growth on gluconeogenic carbon sources. Cloning of acuN has shown that it encodes enolase, an enzyme involved in both glycolysis and gluconeogenesis. The acuN356 mutation is a translocation with a breakpoint in the 5' untranslated region resulting in loss of expression in response to gluconeogenic but not glycolytic carbon sources. Mutations in the acuK and acuM genes affect growth on carbon sources requiring gluconeogenesis and result in loss of induction of the acuF, acuN, and acuG genes by sources of TCA cycle intermediates. Isolation and sequencing of these genes has shown that they encode proteins with similar but distinct Zn(2) Cys(6) DNA-binding domains, suggesting a direct role in transcriptional control of gluconeogenic genes. These genes are conserved in other filamentous ascomycetes, indicating their significance for the regulation of carbon source utilization.

| S-EPMC1893031 | biostudies-literature

Transcriptional changes in the transition from vegetative cells to asexual development in the model fungus Aspergillus nidulans.

Project description:Morphogenesis encompasses programmed changes in gene expression that lead to the development of specialized cell types. In the model fungus Aspergillus nidulans, asexual development involves the formation of characteristic cell types, collectively known as the conidiophore. With the aim of determining the transcriptional changes that occur upon induction of asexual development, we have applied massive mRNA sequencing to compare the expression pattern of 19-h-old submerged vegetative cells (hyphae) with that of similar hyphae after exposure to the air for 5 h. We found that the expression of 2,222 (20.3%) of the predicted 10,943 A. nidulans transcripts was significantly modified after air exposure, 2,035 being downregulated and 187 upregulated. The activation during this transition of genes that belong specifically to the asexual developmental pathway was confirmed. Another remarkable quantitative change occurred in the expression of genes involved in carbon or nitrogen primary metabolism. Genes participating in polar growth or sexual development were transcriptionally repressed, as were those belonging to the HogA/SakA stress response mitogen-activated protein (MAP) kinase pathway. We also identified significant expression changes in several genes purportedly involved in redox balance, transmembrane transport, secondary metabolite production, or transcriptional regulation, mainly binuclear-zinc cluster transcription factors. Genes coding for these four activities were usually grouped in metabolic clusters, which may bring regulatory implications for the induction of asexual development. These results provide a blueprint for further stage-specific gene expression studies during conidiophore development.

| S-EPMC3571305 | biostudies-literature

Phosphoproteome of filamentous fungus Aspergillus nidulans

Project description:We describe thephosphoproteome of filamentous fungus Aspergillus nidulans. Phosphopeptides were enriched using affinity enrichment using titanium dioxide and separated using a convenient ultralong gradient separations on c18 reverse phase columns. Over 1637 phosphopeptides corresponding to 647 phosphoproteins were identified using using a “high-high” strategy using HCD on the novel Q-exactive platform

2014-11-18 | PXD000715 | Pride

RNA silencing gene truncation in the filamentous fungus Aspergillus nidulans.

Project description:The genus Aspergillus is ideally suited for the investigation of RNA silencing evolution because it includes species that have experienced a variety of RNA silencing gene changes. Our work on this subject begins here with the model species Aspergillus nidulans. Filamentous ascomycete fungi generally each encode two of the core RNA silencing proteins, Dicer and Argonaute, but A. nidulans appears to have lost one of each to gene truncation events. Although a role in growth, development, or RNA silencing was not detected for the truncated genes, they do produce spliced and poly(A)-tailed transcripts, suggesting that they may have an undetermined biological function. Population analysis demonstrates that the truncated genes are fixed at the species level and that their full-length orthologs in a closely related species are also unstable. With these gene truncation events, A. nidulans encodes only a single intact Dicer and Argonaute. Their deletion results in morphologically and reproductively normal strains that are incapable of experimental RNA silencing. Thus, our results suggest that the remaining A. nidulans RNA silencing genes have a "nonhousekeeping" function, such as defense against viruses and transposons.

| S-EPMC2238149 | biostudies-literature

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

Project description:The Aspergillus nidulans xprG gene encodes a putative transcriptional activator that is a member of the Ndt80 family in the p53-like superfamily of proteins. Previous studies have shown that XprG controls the production of extracellular proteases in response to starvation. We undertook transcriptional profiling to investigate whether XprG has a wider role as a global regulator of the carbon nutrient stress response. Our microarray data showed that the expression of a large number of genes, including genes involved in secondary metabolism, development, high-affinity glucose uptake and autolysis, were altered in an xprG Δ null mutant. Many of these genes are known to be regulated in response to carbon starvation. We confirmed that sterigmatocystin and penicillin production is reduced in xprG (-) mutants. The loss of fungal mass and secretion of pigments that accompanies fungal autolysis in response to nutrient depletion was accelerated in an xprG1 gain-of-function mutant and decreased or absent in an xprG (-) mutant. The results support the hypothesis that XprG plays a major role in the response to carbon limitation and that nutrient sensing may represent one of the ancestral roles for the p53-like superfamily. Disruption of the AN6015 gene, which encodes a second Ndt80-like protein, showed that it is required for sexual reproduction in A. nidulans.

| S-EPMC3821154 | biostudies-literature

Degradation of intracellular glutathione in Aspergillus nidulans

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

Transcriptional autoregulation and inhibition of mRNA translation of amino acid regulator gene cpcA of filamentous fungus Aspergillus nidulans.

Project description:The CPCA protein of the filamentous fungus Aspergillus nidulans is a member of the c-Jun-like transcriptional activator family. It acts as central transcription factor of the cross-pathway regulatory network of amino acid biosynthesis and is functionally exchangeable for the general control transcriptional activator Gcn4p of Saccharomyces cerevisiae. In contrast to GCN4, expression of cpcA is strongly regulated by two equally important mechanisms with additive effects that lead to a fivefold increased CPCA protein amount under amino acid starvation conditions. One component of cpcA regulation involves a transcriptional autoregulatory mechanism via a CPCA recognition element (CPRE) in the cpcA promoter that causes a sevenfold increased cpcA mRNA level when cells are starved for amino acids. Point mutations in the CPRE cause a constitutively low mRNA level of cpcA and a halved protein level when amino acids are limited. Moreover, two upstream open reading frames (uORFs) in the 5' region of the cpcA mRNA are important for a translational regulatory mechanism. Destruction of both short uORFs results in a sixfold increased CPCA protein level under nonstarvation conditions and a 10-fold increase under starvation conditions. Mutations in both the CPRE and uORF regulatory elements lead to an intermediate effect, with a low cpcA mRNA level but a threefold increased CPCA protein level independent of amino acid availability. These data argue for a combined regulation of cpcA that includes a translational regulation like that of yeast GCN4 as well as a transcriptional regulation like that of the mammalian jun and fos genes.

| S-EPMC59718 | biostudies-literature

Identification of the augmin complex in the filamentous fungus Aspergillus nidulans.

Project description:Augmin is a protein complex that binds to spindle microtubules (MTs), recruits the potent MT nucleator, γ-tubulin, and thereby promotes the centrosome-independent MT generation within mitotic and meiotic spindles. Augmin is essential for acentrosomal spindle assembly, which is commonly observed during mitosis in plants and meiosis in female animals. In many animal somatic cells that possess centrosomes, the centrosome- and augmin-dependent mechanisms work cooperatively for efficient spindle assembly and cytokinesis. Yeasts have lost the augmin genes during evolution. It is hypothesized that their robust MT nucleation from the spindle pole body (SPB), the centrosome-equivalent structure in fungi, compensates for the lack of augmin. Intriguingly, however, a gene homologous to an augmin subunit (Aug6/AUGF) has been found in the genome of filamentous fungi, which has the SPB as a robust MT nucleation centre. Here, we aimed to clarify if the augmin complex is present in filamentous fungi and to identify its role in mitosis. By analysing the Aug6-like gene in the filamentous fungus Aspergillus nidulans, we found that it forms a large complex with several other proteins that share weak but significant homology to known augmin subunits. In A. nidulans, augmin was enriched at the SPB and also associated with spindle MTs during mitosis. However, the augmin gene disruptants did not exhibit growth defects under normal, checkpoint-deficient, or MT-destabilised conditions. Moreover, we obtained no evidence that A. nidulans augmin plays a role in γ-tubulin recruitment or in mitotic cell division. Our study uncovered the conservation of the augmin complex in the fungal species, and further suggests that augmin has several functions, besides mitotic spindle MT nucleation, that are yet to be identified.

| S-EPMC4086812 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data