1
|
Zhang Y, Yang J, Wang S, Chen Y, Zhang G. TMT-Based Proteomic Analysis Reveals the Molecular Mechanisms of Sodium Pheophorbide A against Black Spot Needle Blight Caused by Pestalotiopsis neglecta in Pinus sylvestris var. mongolica. J Fungi (Basel) 2024; 10:102. [PMID: 38392774 PMCID: PMC10889695 DOI: 10.3390/jof10020102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 01/23/2024] [Accepted: 01/25/2024] [Indexed: 02/24/2024] Open
Abstract
Black spot needle blight is a minor disease in Mongolian Scots pine (Pinus sylvestris var. mongolica) caused by Pestalotiopsis neglecta, but it can cause economic losses in severe cases. Sodium pheophorbide a (SPA), an intermediate product of the chlorophyll metabolism pathway, is a compound with photoactivated antifungal activity, which has been previously shown to inhibit the growth of P. neglecta. In this study, SPA significantly reduced the incidence and disease index and enhanced the chlorophyll content and antioxidant enzyme activities of P. sylvestris var. mongolica. To further study the molecular mechanism of the inhibition, we conducted a comparative proteomic analysis of P. neglecta mycelia with and without SPA treatment. The cellular proteins were obtained from P. neglecta mycelial samples and subjected to a tandem mass tag (TMT)-labelling LC-MS/MS analysis. Based on the results of de novo transcriptome assembly, 613 differentially expressed proteins (DEPs) (p < 0.05) were identified, of which 360 were upregulated and 253 downregulated. The 527 annotated DEPs were classified into 50 functional groups according to Gene Ontology and linked to 256 different pathways using the Kyoto Encyclopedia of Genes and Genomes database as a reference. A joint analysis of the transcriptome and proteomics results showed that the top three pathways were Amino acid metabolism, Carbohydrate metabolism, and Lipid metabolism. These results provide new viewpoints into the molecular mechanism of the inhibition of P. neglecta by SPA at the protein level and a theoretical basis for evaluating SPA as an antifungal agent to protect forests.
Collapse
Affiliation(s)
- Yundi Zhang
- Heilongjiang Province Key Laboratory of Forest Protection, School of Forest, Northeast Forestry University, Harbin 150040, China
| | - Jing Yang
- Heilongjiang Province Key Laboratory of Forest Protection, School of Forest, Northeast Forestry University, Harbin 150040, China
- College of Forestry, Guizhou University, Guiyang 550025, China
| | - Shuren Wang
- Heilongjiang Province Key Laboratory of Forest Protection, School of Forest, Northeast Forestry University, Harbin 150040, China
| | - Yunze Chen
- Heilongjiang Province Key Laboratory of Forest Protection, School of Forest, Northeast Forestry University, Harbin 150040, China
- School of Biological Sciences, Guizhou Education University, Guiyang 550018, China
| | - Guocai Zhang
- Heilongjiang Province Key Laboratory of Forest Protection, School of Forest, Northeast Forestry University, Harbin 150040, China
| |
Collapse
|
2
|
Steyer JT, Todd RB. Branched-chain amino acid biosynthesis in fungi. Essays Biochem 2023; 67:865-876. [PMID: 37455545 DOI: 10.1042/ebc20230003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/27/2023] [Accepted: 06/29/2023] [Indexed: 07/18/2023]
Abstract
Branched-chain amino acids (BCAAs)-isoleucine, leucine, and valine-are synthesized by fungi. These amino acids are important components of proteins and secondary metabolites. The biochemical pathway for BCAA biosynthesis is well-characterized in the yeast Saccharomyces cerevisiae. The biosynthesis of these three amino acids is interconnected. Different precursors are metabolized in multiple steps through shared enzymes to produce isoleucine and valine, and the valine biosynthesis pathway branches before the penultimate step to a series of leucine biosynthesis-specific steps to produce leucine. Recent efforts have made advances toward characterization of the BCAA biosynthesis pathway in several fungi, revealing diversity in gene duplication and functional divergence in the genes for these enzymatic steps in different fungi. The BCAA biosynthesis pathway is regulated by the transcription factor LEU3 in S. cerevisiae, and LeuB in Aspergillus nidulans and Aspergillus fumigatus, and the activity of these transcription factors is modulated by the leucine biosynthesis pathway intermediate α-isopropylmalate. Herein, we discuss recent advances in our understanding of the BCAA pathway and its regulation, focusing on filamentous ascomycete fungi and comparison with the well-established process in yeast.
Collapse
Affiliation(s)
- Joel T Steyer
- Department of Plant Pathology, Kansas State University, Manhattan KS, 66506, U.S.A
| | - Richard B Todd
- Department of Plant Pathology, Kansas State University, Manhattan KS, 66506, U.S.A
| |
Collapse
|
3
|
Song P, Dong W. Identification and Characterization of an Antifungal Gene Mt1 from Bacillus subtilis by Affecting Amino Acid Metabolism in Fusarium graminearum. Int J Mol Sci 2023; 24:ijms24108857. [PMID: 37240206 DOI: 10.3390/ijms24108857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 05/07/2023] [Accepted: 05/15/2023] [Indexed: 05/28/2023] Open
Abstract
Fusarium head blight is a devastating disease that causes significant economic losses worldwide. Fusarium graminearum is a crucial pathogen that requires close attention when controlling wheat diseases. Here, we aimed to identify genes and proteins that could confer resistance to F. graminearum. By extensively screening recombinants, we identified an antifungal gene, Mt1 (240 bp), from Bacillus subtilis 330-2. We recombinantly expressed Mt1 in F. graminearum and observed a substantial reduction in the production of aerial mycelium, mycelial growth rate, biomass, and pathogenicity. However, recombinant mycelium and spore morphology remained unchanged. Transcriptome analysis of the recombinants revealed significant down-regulation of genes related to amino acid metabolism and degradation pathways. This finding indicated that Mt1 inhibited amino acid metabolism, leading to limited mycelial growth and, thus, reduced pathogenicity. Based on the results of recombinant phenotypes and transcriptome analysis, we hypothesize that the effect of Mt1 on F. graminearum could be related to the metabolism of branched-chain amino acids (BCAAs), the most affected metabolic pathway with significant down-regulation of several genes. Our findings provide new insights into antifungal gene research and offer promising targets for developing novel strategies to control Fusarium head blight in wheat.
Collapse
Affiliation(s)
- Pei Song
- Key Lab of Crop Disease Monitoring & Safety Control in Hubei Province, Department of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Wubei Dong
- Key Lab of Crop Disease Monitoring & Safety Control in Hubei Province, Department of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| |
Collapse
|
4
|
Role of the Nitrogen Metabolism Regulator TAM1 in Regulation of Cellulase Gene Expression in Trichoderma reesei. Appl Environ Microbiol 2023; 89:e0142122. [PMID: 36602369 PMCID: PMC9888229 DOI: 10.1128/aem.01421-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The filamentous fungus Trichoderma reesei is one of the most prolific cellulase producers and has been established as a model microorganism for investigating mechanisms modulating eukaryotic gene expression. Identification and functional characterization of transcriptional regulators involved in complex and stringent regulation of cellulase genes are, however, not yet complete. Here, a Zn(II)2Cys6-type transcriptional factor TAM1 that is homologous to Aspergillus nidulans TamA involved in nitrogen metabolism, was found not only to regulate ammonium utilization but also to control cellulase gene expression in T. reesei. Whereas Δtam1 cultivated with peptone as a nitrogen source did not exhibit a growth defect that was observed on ammonium, it was still significantly compromised in cellulase biosynthesis. The absence of TAM1 almost fully abrogated the rapid cellulase gene induction in a resting-cell-inducing system. Overexpression of gdh1 encoding the key ammonium assimilatory enzyme in Δtam1 rescued the growth defect on ammonium but not the defect in cellulase gene expression. Of note, mutation of the Zn(II)2Cys6 DNA-binding motif of TAM1 hardly affected cellulase gene expression, while a truncated ARE1 mutant lacking the C-terminal 12 amino acids that are required for the interaction with TAM1 interfered with cellulase biosynthesis. The defect in cellulase induction of Δtam1 was rescued by overexpression of the key transactivator for cellulase gene, XYR1. Our results thus identify a nitrogen metabolism regulator as a new modulator participating in the regulation of induced cellulase gene expression. IMPORTANCE Transcriptional regulators are able to integrate extracellular nutrient signals and exert a combinatorial control over various metabolic genes. A plethora of such factors therefore constitute a complex regulatory network ensuring rapid and accurate cellular response to acquire and utilize nutrients. Despite the in-depth mechanistic studies of functions of the Zn(II)2Cys6-type transcriptional regulator TamA and its orthologues in nitrogen utilization, their involvement in additional physiological processes remains unknown. In this study, we demonstrated that TAM1 exerts a dual regulatory role in mediating ammonium utilization and induced cellulase production in the well known cellulolytic fungus Trichoderma reesei, suggesting a potentially converged regulatory node between nitrogen utilization and cellulase biosynthesis. This study not only contributes to unveiling the intricate regulatory network underlying cellulase gene expression in cellulolytic fungus but also helps expand our knowledge of fungal strategies to achieve efficient and coordinated nutrient acquisition for rapid propagation.
Collapse
|
5
|
Zhang SY, Liang JJ, Liu YQ. Excessive Zinc Ion Caused PC12 Cell Death Correlating with Inhibition of NOS and Increase of RAGE in Cells. Cell Biochem Biophys 2022; 80:755-761. [PMID: 36068383 DOI: 10.1007/s12013-022-01093-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 08/24/2022] [Indexed: 11/03/2022]
Abstract
Zinc ion (Zn2+) is an important functional factor; however, excessive Zn2+ can be toxic. To understand the neurotoxicity of excessive Zn2+ and the underlying mechanism, PC12 cells were treated with excessive Zn2+ and Zn2+ plus N, N, N', N'-Tetrakisethylenediamine (TPEN), a zinc ion chelator agent. Trypan blue and 3-(4,5-dimethyl-2- thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, thiazolyl blue tetrazolium bromide (MTT) assays were used to test cell viability; the relative kits were used to detect the activity of NOS synthase and the content of the receptor for advanced glycation end product (RAGE) in cells. We observed that excessive zinc caused PC12 cell damage and that TPEN partially reversed cell damage caused by excessive zinc. In addition, excessive zinc decreased total nitric oxide synthase (TNOS) activity in cells, in which constitutive nitric oxide synthase (cNOS) activity was significantly reduced; however, inducible nitric oxide synthase (iNOS) activity was extremely promoted. Moreover, excessive zinc upregulated the expression of RAGE, and TPEN effectively reversed the increase in RAGE induced by excessive zinc ions. Therefore, we concluded that excessive zinc caused PC12 cell damage, correlating with the inhibition of NOS and increase of RAGE induced in cells.
Collapse
Affiliation(s)
- Sai-Ya Zhang
- College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Jing-Jing Liang
- College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Yan-Qiang Liu
- College of Life Sciences, Nankai University, Tianjin, 300071, China.
| |
Collapse
|
6
|
Satterlee TR, Williams FN, Nadal M, Glenn AE, Lofton LW, Duke MV, Scheffler BE, Gold SE. Transcriptomic Response of Fusarium verticillioides to Variably Inhibitory Environmental Isolates of Streptomyces. FRONTIERS IN FUNGAL BIOLOGY 2022; 3:894590. [PMID: 37746240 PMCID: PMC10512263 DOI: 10.3389/ffunb.2022.894590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 05/31/2022] [Indexed: 09/26/2023]
Abstract
Fusarium verticillioides is a mycotoxigenic fungus that is a threat to food and feed safety due to its common infection of maize, a global staple crop. A proposed strategy to combat this threat is the use of biological control bacteria that can inhibit the fungus and reduce mycotoxin contamination. In this study, the effect of multiple environmental isolates of Streptomyces on F. verticillioides was examined via transcriptome analysis. The Streptomyces strains ranged from inducing no visible response to dramatic growth inhibition. Transcriptionally, F. verticillioides responded proportionally to strain inhibition with either little to no transcript changes to thousands of genes being differentially expressed. Expression changes in multiple F. verticillioides putative secondary metabolite gene clusters was observed. Interestingly, genes involved in the fusaric acid gene cluster were suppressed by inhibitory strains of Streptomyces. A F. verticillioides beta-lactamase encoding gene (FVEG_13172) was found to be highly induced by specific inhibitory Streptomyces strains and its deletion increased visible response to those strains. This study demonstrates that F. verticillioides does not have an all or nothing response to bacteria it encounters but rather a measured response that is strain specific and proportional to the strength of inhibition.
Collapse
Affiliation(s)
- Timothy R. Satterlee
- United States Department of Agriculture (USDA), Agricultural Research Service (ARS), Toxicology and Mycotoxin Research Unit, United States (US) National Poultry Research Center, Athens, GA, United States
| | - Felicia N. Williams
- United States Department of Agriculture (USDA), Agricultural Research Service (ARS), Toxicology and Mycotoxin Research Unit, United States (US) National Poultry Research Center, Athens, GA, United States
| | - Marina Nadal
- United States Department of Agriculture (USDA), Agricultural Research Service (ARS), Toxicology and Mycotoxin Research Unit, United States (US) National Poultry Research Center, Athens, GA, United States
| | - Anthony E. Glenn
- United States Department of Agriculture (USDA), Agricultural Research Service (ARS), Toxicology and Mycotoxin Research Unit, United States (US) National Poultry Research Center, Athens, GA, United States
| | - Lily W. Lofton
- United States Department of Agriculture (USDA), Agricultural Research Service (ARS), Toxicology and Mycotoxin Research Unit, United States (US) National Poultry Research Center, Athens, GA, United States
| | - Mary V. Duke
- United States Department of Agriculture (USDA), Agricultural Research Service (ARS), Genomics and Bioinformatics Research Unit, Stoneville, MS, United States
| | - Brian E. Scheffler
- United States Department of Agriculture (USDA), Agricultural Research Service (ARS), Genomics and Bioinformatics Research Unit, Stoneville, MS, United States
| | - Scott E. Gold
- United States Department of Agriculture (USDA), Agricultural Research Service (ARS), Toxicology and Mycotoxin Research Unit, United States (US) National Poultry Research Center, Athens, GA, United States
| |
Collapse
|
7
|
Zhao Y, Lee MK, Lim J, Moon H, Park HS, Zheng W, Yu JH. The velvet-activated putative C6 transcription factor VadZ regulates development and sterigmatocystin production in Aspergillus nidulans. Fungal Biol 2022; 126:421-428. [DOI: 10.1016/j.funbio.2022.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 04/22/2022] [Accepted: 05/02/2022] [Indexed: 01/28/2023]
|
8
|
Regulation of the Leucine Metabolism in Mortierella alpina. J Fungi (Basel) 2022; 8:jof8020196. [PMID: 35205950 PMCID: PMC8880518 DOI: 10.3390/jof8020196] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 02/14/2022] [Accepted: 02/15/2022] [Indexed: 12/20/2022] Open
Abstract
The oleaginous fungus Mortierella alpina is a safe source of polyunsaturated fatty acids (PUFA) in industrial food and feed production. Besides PUFA production, pharmaceutically relevant surface-active and antimicrobial oligopeptides were isolated from this basal fungus. Both production of fatty acids and oligopeptides rely on the biosynthesis and high turnover of branched-chain-amino acids (BCAA), especially l-leucine. However, the regulation of BCAA biosynthesis in basal fungi is largely unknown. Here, we report on the regulation of the leucine, isoleucine, and valine metabolism in M. alpina. In contrast to higher fungi, the biosynthetic genes for BCAA are hardly transcriptionally regulated, as shown by qRT-PCR analysis, which suggests a constant production of BCAAs. However, the enzymes of the leucine metabolism are tightly metabolically regulated. Three enzymes of the leucine metabolism were heterologously produced in Escherichia coli, one of which is inhibited by allosteric feedback loops: The key regulator is the α-isopropylmalate synthase LeuA1, which is strongly disabled by l-leucine, α-ketoisocaproate, and propionyl-CoA, the precursor of the odd-chain fatty acid catabolism. Its gene is not related to homologs from higher fungi, but it has been inherited from a phototrophic ancestor by horizontal gene transfer.
Collapse
|
9
|
Dal Grande F, Jamilloux V, Choisne N, Calchera A, Rolshausen G, Petersen M, Schulz M, Nilsson MA, Schmitt I. Transposable Elements in the Genome of the Lichen-Forming Fungus Umbilicaria pustulata and Their Distribution in Different Climate Zones along Elevation. BIOLOGY 2021; 11:biology11010024. [PMID: 35053022 PMCID: PMC8773270 DOI: 10.3390/biology11010024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 12/07/2021] [Accepted: 12/20/2021] [Indexed: 11/16/2022]
Abstract
Transposable elements (TEs) are an important source of genome plasticity across the tree of life. Drift and natural selection are important forces shaping TE distribution and accumulation. Fungi, with their multifaceted phenotypic diversity and relatively small genome size, are ideal models to study the role of TEs in genome evolution and their impact on the host's ecological and life history traits. Here we present an account of all TEs found in a high-quality reference genome of the lichen-forming fungus Umbilicaria pustulata, a macrolichen species comprising two climatic ecotypes: Mediterranean and cold temperate. We trace the occurrence of the newly identified TEs in populations along three elevation gradients using a Pool-Seq approach to identify TE insertions of potential adaptive significance. We found that TEs cover 21.26% of the 32.9 Mbp genome, with LTR Gypsy and Copia clades being the most common TEs. We identified 28 insertions displaying consistent insertion frequency differences between the two host ecotypes across the elevation gradients. Most of the highly differentiated insertions were located near genes, indicating a putative function. This pioneering study of the content and climate niche-specific distribution of TEs in a lichen-forming fungus contributes to understanding the roles of TEs in fungal evolution.
Collapse
Affiliation(s)
- Francesco Dal Grande
- Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Senckenberganlage 25, 60325 Frankfurt am Main, Germany; (A.C.); (M.S.); (M.A.N.); (I.S.)
- LOEWE Centre for Translational Biodiversity Genomics (TBG), Senckenberganlage 25, 60325 Frankfurt am Main, Germany
- Correspondence: ; Tel.: +49-(0)69-7542-1856
| | - Véronique Jamilloux
- INRAE URGI, Centre de Versailles, Bâtiment 18, Route de Saint Cyr, 78026 Versailles, France; (V.J.); (N.C.)
| | - Nathalie Choisne
- INRAE URGI, Centre de Versailles, Bâtiment 18, Route de Saint Cyr, 78026 Versailles, France; (V.J.); (N.C.)
| | - Anjuli Calchera
- Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Senckenberganlage 25, 60325 Frankfurt am Main, Germany; (A.C.); (M.S.); (M.A.N.); (I.S.)
| | - Gregor Rolshausen
- Senckenberg Center for Wildlife Genetics, Clamecystrasse 12, 63571 Gelnhausen, Germany;
| | - Malte Petersen
- Max Planck Institute of Immunobiology and Epigenetics, Stübeweg 51, 79108 Freiburg, Germany;
| | - Meike Schulz
- Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Senckenberganlage 25, 60325 Frankfurt am Main, Germany; (A.C.); (M.S.); (M.A.N.); (I.S.)
| | - Maria A. Nilsson
- Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Senckenberganlage 25, 60325 Frankfurt am Main, Germany; (A.C.); (M.S.); (M.A.N.); (I.S.)
- LOEWE Centre for Translational Biodiversity Genomics (TBG), Senckenberganlage 25, 60325 Frankfurt am Main, Germany
| | - Imke Schmitt
- Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Senckenberganlage 25, 60325 Frankfurt am Main, Germany; (A.C.); (M.S.); (M.A.N.); (I.S.)
- LOEWE Centre for Translational Biodiversity Genomics (TBG), Senckenberganlage 25, 60325 Frankfurt am Main, Germany
- Institut für Ökologie, Evolution und Diversität, Goethe-Universität Frankfurt, Max-von-Laue-Strasse. 9, 60438 Frankfurt am Main, Germany
| |
Collapse
|
10
|
Duplication and Functional Divergence of Branched-Chain Amino Acid Biosynthesis Genes in Aspergillus nidulans. mBio 2021; 12:e0076821. [PMID: 34154419 PMCID: PMC8262921 DOI: 10.1128/mbio.00768-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Fungi, bacteria, and plants, but not animals, synthesize the branched-chain amino acids: leucine, isoleucine, and valine. While branched-chain amino acid (BCAA) biosynthesis has been well characterized in the yeast Saccharomyces cerevisiae, it is incompletely understood in filamentous fungi. The three BCAAs share several early biosynthesis steps before divergence into specific pathways. In Aspergillus nidulans, the genes for the first two dedicated steps in leucine biosynthesis have been characterized, but the final two have not. We used sequence searches of the A. nidulans genome to identify two genes encoding β-isopropylmalate dehydrogenase, which catalyzes the penultimate step of leucine biosynthesis, and six genes encoding BCAA aminotransferase, which catalyzes the final step in biosynthesis of all three BCAA. We have used combinations of gene knockouts to determine the relative contribution of each of these genes to BCAA biosynthesis. While both β-isopropylmalate dehydrogenase genes act in leucine biosynthesis, the two most highly expressed BCAA aminotransferases are responsible for BCAA biosynthesis. We have also characterized the expression of leucine biosynthesis genes using reverse transcriptase-quantitative PCR and found regulation in response to leucine availability is mediated through the Zn(II)2Cys6 transcription factor LeuB. IMPORTANCE Branched-chain amino acid (BCAA) biosynthesis is important for pathogenic fungi to successfully cause disease in human and plant hosts. The enzymes for their production are absent from humans and, therefore, provide potential antifungal targets. While BCAA biosynthesis is well characterized in yeasts, it is poorly understood in filamentous fungal pathogens. Developing a thorough understanding of both the genes encoding the metabolic enzymes for BCAA biosynthesis and how their expression is regulated will inform target selection for antifungal drug development.
Collapse
|
11
|
Ma L, Li X, Ma X, Yu Q, Yu X, Liu Y, Nie C, Zhang Y, Xing F. The Regulatory Mechanism of Water Activities on Aflatoxins Biosynthesis and Conidia Development, and Transcription Factor AtfB Is Involved in This Regulation. Toxins (Basel) 2021; 13:toxins13060431. [PMID: 34205815 PMCID: PMC8235239 DOI: 10.3390/toxins13060431] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 06/02/2021] [Accepted: 06/18/2021] [Indexed: 12/22/2022] Open
Abstract
Peanuts are frequently infected by Aspergillus strains and then contaminated by aflatoxins (AF), which brings out economic losses and health risks. AF production is affected by diverse environmental factors, especially water activity (aw). In this study, A. flavus was inoculated into peanuts with different aw (0.90, 0.95, and 0.99). Both AFB1 yield and conidia production showed the highest level in aw 0.90 treatment. Transcriptional level analyses indicated that AF biosynthesis genes, especially the middle- and later-stage genes, were significantly up-regulated in aw 0.90 than aw 0.95 and 0.99. AtfB could be the pivotal regulator response to aw variations, and could further regulate downstream genes, especially AF biosynthesis genes. The expressions of conidia genes and relevant regulators were also more up-regulated at aw 0.90 than aw 0.95 and 0.99, suggesting that the relative lower aw could increase A. flavus conidia development. Furthermore, transcription factors involved in sexual development and nitrogen metabolism were also modulated by different aw. This research partly clarified the regulatory mechanism of aw on AF biosynthesis and A. flavus development and it would supply some advice for AF prevention in food storage.
Collapse
Affiliation(s)
- Longxue Ma
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (L.M.); (X.L.); (X.M.)
| | - Xu Li
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (L.M.); (X.L.); (X.M.)
| | - Xiaoyun Ma
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (L.M.); (X.L.); (X.M.)
| | - Qiang Yu
- Qingdao Tianxiang Foods Group Co., Qingdao 266737, China; (Q.Y.); (X.Y.)
| | - Xiaohua Yu
- Qingdao Tianxiang Foods Group Co., Qingdao 266737, China; (Q.Y.); (X.Y.)
| | - Yang Liu
- School of Food Science and Engineering, Foshan University, Foshan 528231, China; (Y.L.); (C.N.)
| | - Chengrong Nie
- School of Food Science and Engineering, Foshan University, Foshan 528231, China; (Y.L.); (C.N.)
| | - Yinglong Zhang
- Shandong Institute of Commerce and Technology, Jinan 250103, China
- Correspondence: (Y.Z.); (F.X.)
| | - Fuguo Xing
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (L.M.); (X.L.); (X.M.)
- Correspondence: (Y.Z.); (F.X.)
| |
Collapse
|
12
|
Ji L, Wang J, Luo Q, Ding Q, Tang W, Chen X, Liu L. Enhancing L-malate production of Aspergillus oryzae by nitrogen regulation strategy. Appl Microbiol Biotechnol 2021; 105:3101-3113. [PMID: 33818672 DOI: 10.1007/s00253-021-11149-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 01/14/2021] [Accepted: 01/26/2021] [Indexed: 12/01/2022]
Abstract
Regulating morphology engineering and fermentation of Aspergillus oryzae makes it possible to increase the titer of L-malate. However, the existing L-malate-producing strain has limited L-malate production capacity and the fermentation process is insufficiently mature, which cannot meet the needs of industrial L-malate production. To further increase the L-malate production capacity of A. oryzae, we screened out a mutant strain (FMME-S-38) that produced 79.8 g/L L-malate in 250-mL shake flasks, using a newly developed screening system based on colony morphology on the plate. We further compared the extracellular nitrogen (N1) and intracellular nitrogen (N2) contents of the control and mutant strain (FMME-S-38) to determine the relationship between the curve of nitrogen content (N1 and N2) and the L-malate titer. This correlation was then used to optimize the conditions for developing a novel nitrogen supply strategy (initial tryptone concentration of 6.5 g/L and feeding with 3 g/L tryptone at 24 h). Fermentation in a 7.5-L fermentor under the optimized conditions further increased the titer and productivity of L-malate to 143.3 g/L and 1.19 g/L/h, respectively, corresponding to 164.9 g/L and 1.14 g/L/h in a 30-L fermentor. This nitrogen regulation-based strategy cannot only enhance industrial-scale L-malate production but also has generalizability and the potential to increase the production of similar metabolites.Key Points• Construction of a new screening system based on colony morphology on the plate.• A novel nitrogen regulation strategy used to regulate the production of L-malate.• A nitrogen supply strategy used to maximize the production of L-malate.
Collapse
Affiliation(s)
- Lihao Ji
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Ju Wang
- College of Food Engineering, Anhui Science and Technology University, Chuzhou, 233100, Anhui, China
| | - Qiuling Luo
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Qiang Ding
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Wenxiu Tang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Xiulai Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Liming Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China. .,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China.
| |
Collapse
|
13
|
Involvement of BbTpc1, an important Zn(II) 2Cys 6 transcriptional regulator, in chitin biosynthesis, fungal development and virulence of an insect mycopathogen. Int J Biol Macromol 2020; 166:1162-1172. [PMID: 33159944 DOI: 10.1016/j.ijbiomac.2020.10.271] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/29/2020] [Accepted: 10/31/2020] [Indexed: 01/27/2023]
Abstract
Chitin is one of the major components of the fungal cell wall and contributes to the mechanical strength and shape of the fungal cell. Zn(II)2Cys6 transcription factors are unique to the fungal kingdom and have a variety of functions in some fungi. However, the mechanisms by which Zn(II)2Cys6 proteins affect entomopathogenic fungi are largely unknown. Here, we characterized the Zn(II)2Cys6 transcription factor BbTpc1 in the insect pathogenic fungus Beauveria bassiana. Disruption of BbTpc1 resulted in a distinct changes in vegetative growth and septation patterns, and a significant decrease in conidia and blastospore yield. The ΔBbTpc1 mutant displayed impaired resistance to chemical stresses and heat shock and attenuated virulence in topical and intrahemocoel injection assays. Importantly, the ΔBbTpc1 mutant had an abnormal cell wall with altered wall thickness and chitin synthesis, which were accompanied by transcriptional repression of the chitin synthetase family genes. In addition, comparative transcriptomics revealed that deletion of BbTpc1 altered fungal asexual reproduction via different genetic pathways. These data revealed that BbTpc1 regulates fungal development, chitin synthesis and biological control potential in B. bassiana.
Collapse
|
14
|
Orasch T, Dietl AM, Shadkchan Y, Binder U, Bauer I, Lass-Flörl C, Osherov N, Haas H. The leucine biosynthetic pathway is crucial for adaptation to iron starvation and virulence in Aspergillus fumigatus. Virulence 2020; 10:925-934. [PMID: 31694453 PMCID: PMC6844326 DOI: 10.1080/21505594.2019.1682760] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
In contrast to mammalia, fungi are able to synthesize the branched-chain amino acid leucine de novo. Recently, the transcription factor LeuB has been shown to cross-regulate leucine biosynthesis, nitrogen metabolism and iron homeostasis in Aspergillus fumigatus, the most common human mold pathogen. Moreover, the leucine biosynthetic pathway intermediate α-isopropylmalate (α-IPM) has previously been shown to posttranslationally activate LeuB homologs in S. cerevisiae and A. nidulans. Here, we demonstrate that in A. fumigatus inactivation of both leucine biosynthetic enzymes α-IPM synthase (LeuC), which disrupts α-IPM synthesis, and α-IPM isomerase (LeuA), which causes cellular α-IPM accumulation, results in leucine auxotrophy. However, compared to lack of LeuA, lack of LeuC resulted in increased leucine dependence, a growth defect during iron starvation and decreased expression of LeuB-regulated genes including genes involved in iron acquisition. Lack of either LeuA or LeuC decreased virulence in an insect infection model, and inactivation of LeuC rendered A. fumigatus avirulent in a pulmonary aspergillosis mouse model. Taken together, we demonstrate that the lack of two leucine biosynthetic enzymes, LeuA and LeuC, results in significant phenotypic consequences indicating that the regulator LeuB is activated by α-IPM in A. fumigatus and that the leucine biosynthetic pathway is an attractive target for the development of antifungal drugs.
Collapse
Affiliation(s)
- Thomas Orasch
- Institute of Molecular Biology, Medical University of Innsbruck, Innsbruck, Austria
| | - Anna-Maria Dietl
- Institute of Molecular Biology, Medical University of Innsbruck, Innsbruck, Austria
| | - Yana Shadkchan
- Aspergillus and Antifungal Research Laboratory, Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel-Aviv, Israel
| | - Ulrike Binder
- Institute of Hygiene & Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Ingo Bauer
- Institute of Molecular Biology, Medical University of Innsbruck, Innsbruck, Austria
| | - Cornelia Lass-Flörl
- Institute of Hygiene & Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Nir Osherov
- Aspergillus and Antifungal Research Laboratory, Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel-Aviv, Israel
| | - Hubertus Haas
- Institute of Molecular Biology, Medical University of Innsbruck, Innsbruck, Austria
| |
Collapse
|
15
|
Wei YY, Yu Q, Dong B, Zhang Y, Liu XH, Lin FC, Liang S. MoLEU1, MoLEU2, and MoLEU4 regulated by MoLEU3 are involved in leucine biosynthesis, fungal development, and pathogenicity in Magnaporthe oryzae. ENVIRONMENTAL MICROBIOLOGY REPORTS 2019; 11:784-796. [PMID: 31621205 DOI: 10.1111/1758-2229.12800] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 10/13/2019] [Accepted: 10/13/2019] [Indexed: 06/10/2023]
Abstract
Amino acids are vital components in cell metabolism. Leucine is a regulatory factor that generates significant impact on protein synthesis/turnover, modulates diverse cellular signalling pathways and participates in oxidative processes and immune responses. Here, we identified and characterized the functions of a leucine-associated Zn2 Cys6 -type transcription factor, MoLeu3. Disruption of MoLEU3 resulted in significantly reduced pathogenicity in barley and rice. Quantitative RT-PCR showed that the expression levels of the putative leucine biosynthesis-related genes, MoLEU1, MoLEU2 and MoLEU4 were downregulated in the ΔMoleu3 mutant. We used high-throughput gene knockout method to generate the null mutants of MoLEU1, MoLEU2 and MoLEU4 respectively. The ΔMoleu1, ΔMoleu2 and ΔMoleu4 mutants are leucine auxotroph and showed similar phenotypic characterizations, including reduced conidiation, delayed mobilization and degradation of glycogen and lipid droplets, limited appressorium-mediated penetration, and restricted invasive hyphae growth within host cells. Collectively, MoLEU1, MoLEU2, and MoLEU4 regulated by MoLEU3 play crucial roles in fungal development and infectious processes through modulation of leucine biosynthesis in Magnaporthe oryzae.
Collapse
Affiliation(s)
- Yun-Yun Wei
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Qin Yu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Bo Dong
- Markey Cancer Center, the University of Kentucky, College of Medicine, Lexington, KY, 40506, USA
| | - Yong Zhang
- Quzhou Municipal Plant Protection and Quarantine Station, Quzhou Municipal Bureau of Agriculture, Quzhou, 324000, China
| | - Xiao-Hong Liu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Fu-Cheng Lin
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Shuang Liang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, 310024, China
- Laboratory of Proteomic Big Data, Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, 310024, China
| |
Collapse
|
16
|
Que Y, Yue X, Yang N, Xu Z, Tang S, Wang C, Lv W, Xu L, Talbot NJ, Wang Z. Leucine biosynthesis is required for infection-related morphogenesis and pathogenicity in the rice blast fungus Magnaporthe oryzae. Curr Genet 2019; 66:155-171. [PMID: 31263943 DOI: 10.1007/s00294-019-01009-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 06/26/2019] [Accepted: 06/27/2019] [Indexed: 11/29/2022]
Abstract
The rice blast fungus Magnaporthe oryzae causes one of the most devastating crop diseases world-wide and new control strategies for blast disease are urgently required. We have used insertional mutagenesis in M. oryzae to define biological processes that are critical for blast disease. Here, we report the identification of LEU2A by T-DNA mutagenesis, which putatively encodes 3-isopropylmalate dehydrogenase (3-IPMDH) required for leucine biosynthesis, implicating that synthesis of this amino acid is required for fungal pathogenesis. M. oryzae contains a further predicted 3-IPMDH gene (LEU2B), two 2-isopropylmalate synthase (2-IPMS) genes (LEU4 and LEU9) and an isopropylmalate isomerase (IPMI) gene (LEU1). Targeted gene deletion mutants of LEU1, LEU2A or LEU4 are leucine auxotrophs, and severely defective in pathogenicity. All phenotypes associated with mutants lacking LEU1, LEU2A or LEU4 could be overcome by adding exogenous leucine. The expression levels of LEU1, LEU2A or LEU4 genes were significantly down-regulated by deletion of the transcription factor gene LEU3, an ortholog of Saccharomyces cerevisiae LEU3. We also functionally characterized leucine biosynthesis genes in the wheat pathogen Fusarium graminearum and found that FgLEU1, FgLEU3 and FgLEU4 are essential for wheat head blight disease, suggesting that leucine biosynthesis in filamentous fungal pathogens may be a conserved factor for fungal pathogenicity and, therefore, a potential target for disease control.
Collapse
Affiliation(s)
- Yawei Que
- State Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Xiaofeng Yue
- State Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Nan Yang
- State Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Zhe Xu
- State Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Shuai Tang
- State Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Chunyan Wang
- State Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Wuyun Lv
- State Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Lin Xu
- State Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Nicholas J Talbot
- The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Zhengyi Wang
- State Key Laboratory for Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, People's Republic of China.
| |
Collapse
|
17
|
Grau MF, Entwistle R, Chiang YM, Ahuja M, Oakley CE, Akashi T, Wang CCC, Todd RB, Oakley BR. Hybrid Transcription Factor Engineering Activates the Silent Secondary Metabolite Gene Cluster for (+)-Asperlin in Aspergillus nidulans. ACS Chem Biol 2018; 13:3193-3205. [PMID: 30339758 DOI: 10.1021/acschembio.8b00679] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Fungi are a major source of valuable bioactive secondary metabolites (SMs). These compounds are synthesized by enzymes encoded by genes that are clustered in the genome. The vast majority of SM biosynthetic gene clusters are not expressed under normal growth conditions, and their products are unknown. Developing methods for activation of these silent gene clusters offers the potential for discovering many valuable new fungal SMs. While a number of useful approaches have been developed, they each have limitations, and additional tools are needed. One approach, upregulation of SM gene cluster-specific transcription factors that are associated with many SM gene clusters, has worked extremely well in some cases, but it has failed more often than it has succeeded. Taking advantage of transcription factor domain modularity, we developed a new approach. We fused the DNA-binding domain of a transcription factor associated with a silent SM gene cluster with the activation domain of a robust SM transcription factor, AfoA. Expression of this hybrid transcription factor activated transcription of the genes in the target cluster and production of the antibiotic (+)-asperlin. Deletion of cluster genes confirmed that the cluster is responsible for (+)-asperlin production, and we designate it the aln cluster. Separately, coinduction of expression of two aln cluster genes revealed the pathway intermediate (2 Z,4 Z,6 E)-octa-2,4,6-trienoic acid, a compound with photoprotectant properties. Our findings demonstrate the potential of our novel synthetic hybrid transcription factor strategy to discover the products of other silent fungal SM gene clusters.
Collapse
Affiliation(s)
- Michelle F. Grau
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California 90089, United States
| | - Ruth Entwistle
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045, United States
| | - Yi-Ming Chiang
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California 90089, United States
- Department of Pharmacy, Chia Nan University of Pharmacy and Science, Tainan City 71710, Taiwan
| | - Manmeet Ahuja
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045, United States
| | - C. Elizabeth Oakley
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045, United States
| | - Tomohiro Akashi
- Division of OMICS Analysis, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Clay C. C. Wang
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California 90089, United States
- Department of Chemistry, Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, California 90089, United States
| | - Richard B. Todd
- Department of Plant Pathology, Kansas State University, 4024 Throckmorton Plant Sciences Center, Manhattan, Kansas 66506, United States
| | - Berl R. Oakley
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045, United States
| |
Collapse
|
18
|
Long N, Orasch T, Zhang S, Gao L, Xu X, Hortschansky P, Ye J, Zhang F, Xu K, Gsaller F, Straßburger M, Binder U, Heinekamp T, Brakhage AA, Haas H, Lu L. The Zn2Cys6-type transcription factor LeuB cross-links regulation of leucine biosynthesis and iron acquisition in Aspergillus fumigatus. PLoS Genet 2018; 14:e1007762. [PMID: 30365497 PMCID: PMC6221358 DOI: 10.1371/journal.pgen.1007762] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 11/07/2018] [Accepted: 10/12/2018] [Indexed: 12/21/2022] Open
Abstract
Both branched-chain amino acids (BCAA) and iron are essential nutrients for eukaryotic cells. Previously, the Zn2Cys6-type transcription factor Leu3/LeuB was shown to play a crucial role in regulation of BCAA biosynthesis and nitrogen metabolism in Saccharomyces cerevisiae and Aspergillus nidulans. In this study, we found that the A. fumigatus homolog LeuB is involved in regulation of not only BCAA biosynthesis and nitrogen metabolism but also iron acquisition including siderophore metabolism. Lack of LeuB caused a growth defect, which was cured by supplementation with leucine or iron. Moreover, simultaneous inactivation of LeuB and HapX, a bZIP transcription factor required for adaptation to iron starvation, significantly aggravated the growth defect caused by inactivation of one of these regulators during iron starvation. In agreement with a direct role in regulation of both BCAA and iron metabolism, LeuB was found to bind to phylogenetically conserved motifs in promoters of genes involved in BCAA biosynthesis, nitrogen metabolism, and iron acquisition in vitro and in vivo, and was required for full activation of their expression. Lack of LeuB also caused activation of protease activity and autophagy via leucine depletion. Moreover, LeuB inactivation resulted in virulence attenuation of A. fumigatus in Galleria mellonella. Taken together, this study identified a previously uncharacterized direct cross-regulation of BCCA biosynthesis, nitrogen metabolism and iron homeostasis as well as proteolysis. Adaptation to the host niche is an essential attribute of pathogens. Here we found that the Zn2Cys6-type transcription factor LeuB cross-regulates branched-chain amino acid biosynthesis, nitrogen metabolism, iron acquisition via siderophores, and proteasome activity in the mold Aspergillus fumigatus. Lack of this regulatory circuit impaired virulence in an insect infection model. Mammals do neither express Zn2Cys6-type transcription factors nor have the capacity to produce branched-chain amino acids or siderophores. Consequently, this regulatory circuit is a paradigm for fungal pathogen-specific adaptation to the host niche.
Collapse
Affiliation(s)
- Nanbiao Long
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, China
- Department of Laboratory Medicine, Shaoyang University, Shaoyang, China
| | - Thomas Orasch
- Division of Molecular Biology/Biocenter, Medical University of Innsbruck, Innrain, Innsbruck, Austria
| | - Shizhu Zhang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Lu Gao
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Xiaoling Xu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Peter Hortschansky
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), and Friedrich Schiller University Jena, Jena, Germany
| | - Jing Ye
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Fenli Zhang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Kai Xu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Fabio Gsaller
- Division of Molecular Biology/Biocenter, Medical University of Innsbruck, Innrain, Innsbruck, Austria
| | - Maria Straßburger
- Transfer Group Anti-infectives, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany
| | - Ulrike Binder
- Division of Hygiene & Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Thorsten Heinekamp
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), and Friedrich Schiller University Jena, Jena, Germany
| | - Axel A. Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), and Friedrich Schiller University Jena, Jena, Germany
| | - Hubertus Haas
- Division of Molecular Biology/Biocenter, Medical University of Innsbruck, Innrain, Innsbruck, Austria
- * E-mail: (HH); (LL)
| | - Ling Lu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, China
- * E-mail: (HH); (LL)
| |
Collapse
|
19
|
Ding Q, Luo Q, Zhou J, Chen X, Liu L. Enhancing L-malate production of Aspergillus oryzae FMME218-37 by improving inorganic nitrogen utilization. Appl Microbiol Biotechnol 2018; 102:8739-8751. [PMID: 30109399 DOI: 10.1007/s00253-018-9272-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 06/30/2018] [Accepted: 07/24/2018] [Indexed: 02/06/2023]
Abstract
Microbial L-malate production from renewable feedstock is a promising alternative to petroleum-based chemical synthesis. However, high L-malate production of Aspergillus oryzae was achieved to date using organic nitrogen, with inorganic nitrogen still unable to meet industrial applications. In the current study, we constructed a screening system and nitrogen supply strategy to improve L-malate production with ammonium sulphate [(NH4)2SO4] as the sole nitrogen source. First, we generated and identified a high-producing mutant FMME218-37, which stably boosted L-malate production from 30.73 to 78.12 g/L, using a combined screening system with morphological characteristics. Then, by analyzing the fermentation parameters and physiological characteristics, we further speculated the key factor was the unbalance of carbon and nitrogen absorption. Finally, the titer and productivity of L-malate was increased to 95.2 g/L and 0.57 g/(L h) by regulating the nitrogen supply module to balance carbon and nitrogen absorption, which represented the highest level in A. oryzae with (NH4)2SO4 as nitrogen source achieved to date. Moreover, our findings using a low-cost substrate may lead to building an economical cell factory of A. oryzae for L-malate production.
Collapse
Affiliation(s)
- Qiang Ding
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China.,National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, 214122, China
| | - Qiuling Luo
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China.,National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, 214122, China
| | - Jie Zhou
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China.,National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, 214122, China
| | - Xiulai Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China.,National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, 214122, China
| | - Liming Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, China. .,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China. .,National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, 214122, China.
| |
Collapse
|
20
|
Palavecino-Ruiz M, Bermudez-Moretti M, Correa-Garcia S. Unravelling the transcriptional regulation of Saccharomyces cerevisiae UGA genes: the dual role of transcription factor Leu3. MICROBIOLOGY-SGM 2017; 163:1692-1701. [PMID: 29058647 DOI: 10.1099/mic.0.000560] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Yeast cells can use γ-aminobutyric acid (GABA), a non-protein amino acid, as a nitrogen source that is mainly imported by the permease Uga4 and catabolized by the enzymes GABA transaminase and succinate-semialdehyde dehydrogenase, encoded by the UGA1 and UGA2 genes, respectively. The three UGA genes are inducible by GABA and subject to nitrogen catabolite repression. Hence, their regulation occurs through two mechanisms, one dependent on the inducer and the other on nitrogen source quality. The aim of this work was to better understand the molecular mechanisms of transcription factors acting on different regulatory elements present in UGA promoters, such as Uga3, Dal81, Leu3 and the GATA factors, and to establish the mechanism of the concerted action between them. We found that Gat1 plays an important role in the induction of UGA4 transcription by GABA and that Gzf3 has an effect in cells grown in a poor nitrogen source such as proline and that this effect is positive on UGA4 expression. We also found that Gln3 and Dal80 affect the interaction of Uga3 and Dal81 on UGA promoters. Moreover, our results indicated that the repressing activity of Leu3 on UGA4 and UGA1 occurs through Dal80 since we demonstrated that Leu3 facilitates Dal80 interaction with DNA. However, when the expression of GATA factors is null or negligible, Leu3 functions as an activator.
Collapse
Affiliation(s)
- Marcos Palavecino-Ruiz
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN). Buenos Aires, Argentina
| | - Mariana Bermudez-Moretti
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN). Buenos Aires, Argentina
| | - Susana Correa-Garcia
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN). Buenos Aires, Argentina
| |
Collapse
|
21
|
Luo X, Mao H, Wei Y, Cai J, Xie C, Sui A, Yang X, Dong J. The fungal-specific transcription factor Vdpf influences conidia production, melanized microsclerotia formation and pathogenicity in Verticillium dahliae. MOLECULAR PLANT PATHOLOGY 2016; 17:1364-1381. [PMID: 26857810 PMCID: PMC6638448 DOI: 10.1111/mpp.12367] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 01/05/2016] [Accepted: 01/07/2016] [Indexed: 05/05/2023]
Abstract
Verticillium dahliae is a soil-borne, hemibiotrophic phytopathogenic fungus that causes wilting in crop plants. Here, we constructed a random insertional mutant library using Agrobacterium tumefaciens-mediated transformation to study the pathogenicity and regulatory mechanisms of V. dahliae. The fungal-specific transcription factor-encoding gene Vdpf was shown to be associated with vegetative growth and virulence, with the highest transcript expression occurring during conidia formation in the V991 strain. The deletion mutants (ΔVdpf) and insertion mutants (IMΔVdpf) produced fewer conidia than did the wild-type (WT) fungi, which contributed to the reduced virulence. Unlike the WT, the complemented strains and IMΔVdpf, ΔVdpf formed swollen, thick-walled and hyaline mycelium rather than melanized microsclerotia. The ΔVdpf mutants were melanin deficient, with undetectable expression of melanin biosynthesis-related genes (Brn1, Brn2 and Scd1). The melanin deficiency was related to cyclic adenosine monophosphate (cAMP) and the G-protein-coupled signalling pathways in this study. Similar to the WT and complemented strains, the ΔVdpf and IMΔVdpf mutants could also successfully penetrate into cotton and tobacco roots, but displayed reduced virulence because of lower biomass in the plant roots and significantly reduced expression of pathogenicity-related genes in V. dahliae. In conclusion, these results provide insights into the role of Vdpf in melanized microsclerotia formation, conidia production and pathogenicity.
Collapse
Affiliation(s)
- Xiumei Luo
- The School of Life ScienceSouthwest UniversityChongqing400715China
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations and the College of Life ScienceChongqing Normal UniversityChongqing401331China
| | - Hongqiang Mao
- The School of Life ScienceSouthwest UniversityChongqing400715China
| | - Yunming Wei
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations and the College of Life ScienceChongqing Normal UniversityChongqing401331China
| | - Jie Cai
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations and the College of Life ScienceChongqing Normal UniversityChongqing401331China
| | - Chengjian Xie
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations and the College of Life ScienceChongqing Normal UniversityChongqing401331China
| | - Anping Sui
- The School of Life ScienceSouthwest UniversityChongqing400715China
| | - Xingyong Yang
- The Chongqing Key Laboratory of Molecular Biology of Plant Environmental Adaptations and the College of Life ScienceChongqing Normal UniversityChongqing401331China
| | - Jinyan Dong
- The School of Life ScienceSouthwest UniversityChongqing400715China
| |
Collapse
|
22
|
Tudzynski B. Nitrogen regulation of fungal secondary metabolism in fungi. Front Microbiol 2014; 5:656. [PMID: 25506342 PMCID: PMC4246892 DOI: 10.3389/fmicb.2014.00656] [Citation(s) in RCA: 170] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 11/13/2014] [Indexed: 11/13/2022] Open
Abstract
Fungi occupy diverse environments where they are constantly challenged by stressors such as extreme pH, temperature, UV exposure, and nutrient deprivation. Nitrogen is an essential requirement for growth, and the ability to metabolize a wide variety of nitrogen sources enables fungi to colonize different environmental niches and survive nutrient limitations. Favored nitrogen sources, particularly ammonium and glutamine, are used preferentially, while the expression of genes required for the use of various secondary nitrogen sources is subject to a regulatory mechanism called nitrogen metabolite repression. Studies on gene regulation in response to nitrogen availability were carried out first in Saccharomyces cerevisiae, Aspergillus nidulans, and Neurospora crassa. These studies revealed that fungi respond to changes in nitrogen availability with physiological and morphological alterations and activation of differentiation processes. In all fungal species studied, the major GATA transcription factor AreA and its co-repressor Nmr are central players of the nitrogen regulatory network. In addition to growth and development, the quality and quantity of nitrogen also affects the formation of a broad range of secondary metabolites (SMs). Recent studies, mainly on species of the genus Fusarium, revealed that AreA does not only regulate a large set of nitrogen catabolic genes, but can also be involved in regulating production of SMs. Furthermore, several other regulators, e.g., a second GATA transcription factor, AreB, that was proposed to negatively control nitrogen catabolic genes by competing with AreA for binding to GATA elements, was shown to act as activator of some nitrogen-repressed as well as nitrogen-induced SM gene clusters. This review highlights our latest understanding of canonical (AreA-dependent) and non-canonical nitrogen regulation mechanisms by which fungi may regulate biosynthesis of certain SMs in response to nitrogen availability.
Collapse
Affiliation(s)
- Bettina Tudzynski
- Institute of Biology and Biotechnology of Plants, Westfaelische Wilhelms-University Muenster Muenster, Germany
| |
Collapse
|
23
|
Downes DJ, Davis MA, Wong KH, Kreutzberger SD, Hynes MJ, Todd RB. Dual DNA binding and coactivator functions ofAspergillus nidulans TamA, a Zn(II)2Cys6 transcription factor. Mol Microbiol 2014; 92:1198-211. [DOI: 10.1111/mmi.12620] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/14/2014] [Indexed: 01/19/2023]
Affiliation(s)
- Damien J. Downes
- Department of Plant Pathology; Kansas State University; 4024 Throckmorton Plant Sciences Center Manhattan KS 66506 USA
- Department of Genetics; The University of Melbourne; Parkville Vic. 3010 Australia
| | - Meryl A. Davis
- Department of Genetics; The University of Melbourne; Parkville Vic. 3010 Australia
| | - Koon Ho Wong
- Department of Biological Chemistry & Molecular Pharmacology; Harvard Medical School; 240 Longwood Ave, Room C2-325 Boston MA 02115 USA
- Faculty of Health Sciences; University of Macau; Macau SAR China
| | - Sara D. Kreutzberger
- Department of Genetics; The University of Melbourne; Parkville Vic. 3010 Australia
| | - Michael J. Hynes
- Department of Genetics; The University of Melbourne; Parkville Vic. 3010 Australia
| | - Richard B. Todd
- Department of Plant Pathology; Kansas State University; 4024 Throckmorton Plant Sciences Center Manhattan KS 66506 USA
- Department of Genetics; The University of Melbourne; Parkville Vic. 3010 Australia
| |
Collapse
|
24
|
Multiple nuclear localization signals mediate nuclear localization of the GATA transcription factor AreA. EUKARYOTIC CELL 2014; 13:527-38. [PMID: 24562911 DOI: 10.1128/ec.00040-14] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The Aspergillus nidulans GATA transcription factor AreA activates transcription of nitrogen metabolic genes in response to nitrogen limitation and is known to accumulate in the nucleus during nitrogen starvation. Sequence analysis of AreA revealed multiple nuclear localization signals (NLSs), five putative classical NLSs conserved in fungal AreA orthologs but not in the Saccharomyces cerevisiae functional orthologs Gln3p and Gat1p, and one putative noncanonical RRX33RXR bipartite NLS within the DNA-binding domain. In order to identify the functional NLSs in AreA, we constructed areA mutants with mutations in individual putative NLSs or combinations of putative NLSs and strains expressing green fluorescent protein (GFP)-AreA NLS fusion genes. Deletion of all five classical NLSs individually or collectively did not affect utilization of nitrogen sources or AreA-dependent gene expression and did not prevent AreA nuclear localization. Mutation of the bipartite NLS conferred the inability to utilize alternative nitrogen sources and abolished AreA-dependent gene expression likely due to effects on DNA binding but did not prevent AreA nuclear localization. Mutation of all six NLSs simultaneously prevented AreA nuclear accumulation. The bipartite NLS alone strongly directed GFP to the nucleus, whereas the classical NLSs collaborated to direct GFP to the nucleus. Therefore, AreA contains multiple conserved NLSs, which show redundancy and together function to mediate nuclear import. The noncanonical bipartite NLS is conserved in GATA factors from Aspergillus, yeast, and mammals, indicating an ancient origin.
Collapse
|