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Bodnár V, Antal K, de Vries RP, Pócsi I, Emri T. Aspergillus nidulans gfdB, Encoding the Hyperosmotic Stress Protein Glycerol-3-phosphate Dehydrogenase, Disrupts Osmoadaptation in Aspergillus wentii. J Fungi (Basel) 2024; 10:291. [PMID: 38667962 PMCID: PMC11051529 DOI: 10.3390/jof10040291] [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: 02/20/2024] [Revised: 03/30/2024] [Accepted: 04/10/2024] [Indexed: 04/28/2024] Open
Abstract
The genome of the osmophilic Aspergillus wentii, unlike that of the osmotolerant Aspergillus nidulans, contains only the gfdA, but not the gfdB, glycerol 3-phosphate dehydrogenase gene. Here, we studied transcriptomic changes of A. nidulans (reference strain and ΔgfdB gene deletion mutant) and A. wentii (reference strain and An-gfdB expressing mutant) elicited by high osmolarity. A. nidulans showed a canonic hyperosmotic stress response characterized by the upregulation of the trehalose and glycerol metabolism genes (including gfdB), as well as the genes of the high-osmolarity glycerol (HOG) map kinase pathway. The deletion of gfdB caused only negligible alterations in the transcriptome, suggesting that the glycerol metabolism was flexible enough to compensate for the missing GfdB activity in this species. A. wentii responded differently to increased osmolarity than did A. nidulans, e.g., the bulk upregulation of the glycerol and trehalose metabolism genes, along with the HOG pathway genes, was not detected. The expression of An-gfdB in A. wentii did not abolish osmophily, but it reduced growth and caused much bigger alterations in the transcriptome than did the missing gfdB gene in A. nidulans. Flexible glycerol metabolism and hence, two differently regulated gfd genes, may be more beneficial for osmotolerant (living under changing osmolarity) than for osmophilic (living under constantly high osmolarity) species.
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Affiliation(s)
- Veronika Bodnár
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary;
- Doctoral School of Nutrition and Food Sciences, University of Debrecen, H-4032 Debrecen, Hungary
| | - Károly Antal
- Department of Zoology, Eszterházy Károly Catholic University, Eszterházy tér 1, H-3300 Eger, Hungary;
| | - Ronald P. de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, 3584 CS Utrecht, The Netherlands;
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary;
- HUN-REN–UD Fungal Stress Biology Research Group, H-4032 Debrecen, Hungary
| | - Tamás Emri
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary;
- HUN-REN–UD Fungal Stress Biology Research Group, H-4032 Debrecen, Hungary
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Li Y, Li Y, Lu H, Sun T, Gao J, Zhang J, Shen Q, Yu Z. The bZIP transcription factor ATF1 regulates blue light and oxidative stress responses in Trichoderma guizhouense. MLIFE 2023; 2:365-377. [PMID: 38818272 PMCID: PMC10989065 DOI: 10.1002/mlf2.12089] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 08/23/2023] [Accepted: 09/17/2023] [Indexed: 06/01/2024]
Abstract
In several filamentous fungi, incident light and environmental stress signaling share the mitogen-activated protein kinase (MAPK) HOG (SAK) pathway. It has been revealed that short-term illumination with blue light triggers the activation of the HOG pathway in Trichoderma spp. In this study, we demonstrate the crucial role of the basic leucine zipper transcription factor ATF1 in blue light responses and signaling downstream of the MAPK HOG1 in Trichoderma guizhouense. The lack of ATF1 severely impaired photoconidiation and delayed vegetative growth and conidial germination. Upon blue light or H2O2 stimuli, HOG1 interacted with ATF1 in the nucleus. Genome-wide transcriptome analyses revealed that 61.8% (509 out of 824) and 85.2% (702 out of 824) of blue light-regulated genes depended on ATF1 and HOG1, respectively, of which 58.4% (481 out of 824) were regulated by both of them. Our results also show that blue light promoted conidial germination and HOG1 and ATF1 played opposite roles in controlling conidial germination in the dark. Additionally, the lack of ATF1 led to reduced oxidative stress resistance, probably because of the downregulation of catalase-encoding genes. Overall, our results demonstrate that ATF1 is the downstream component of HOG1 and is responsible for blue light responses, conidial germination, vegetative growth, and oxidative stress resistance in T. guizhouense.
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Affiliation(s)
- Yifan Li
- Nanjing Agricultural University, Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic‐based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource UtilizationAgricultural Microbial Resources Protection and Germplasm Innovation and Utilization Center of Jiangsu ProvinceNanjingChina
| | - Yanshen Li
- Nanjing Agricultural University, Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic‐based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource UtilizationAgricultural Microbial Resources Protection and Germplasm Innovation and Utilization Center of Jiangsu ProvinceNanjingChina
| | - Huanhong Lu
- Nanjing Agricultural University, Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic‐based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource UtilizationAgricultural Microbial Resources Protection and Germplasm Innovation and Utilization Center of Jiangsu ProvinceNanjingChina
| | - Tingting Sun
- Nanjing Agricultural University, Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic‐based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource UtilizationAgricultural Microbial Resources Protection and Germplasm Innovation and Utilization Center of Jiangsu ProvinceNanjingChina
| | - Jia Gao
- Department of MicrobiologyKarlsruhe Institute of Technology (KIT)—South Campus, Institute for Applied BiosciencesKarlsruheGermany
| | - Jian Zhang
- Nanjing Agricultural University, Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic‐based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource UtilizationAgricultural Microbial Resources Protection and Germplasm Innovation and Utilization Center of Jiangsu ProvinceNanjingChina
| | - Qirong Shen
- Nanjing Agricultural University, Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic‐based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource UtilizationAgricultural Microbial Resources Protection and Germplasm Innovation and Utilization Center of Jiangsu ProvinceNanjingChina
| | - Zhenzhong Yu
- Nanjing Agricultural University, Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic‐based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource UtilizationAgricultural Microbial Resources Protection and Germplasm Innovation and Utilization Center of Jiangsu ProvinceNanjingChina
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Pákozdi K, Emri T, Antal K, Pócsi I. Global Transcriptomic Changes Elicited by sodB Deletion and Menadione Exposure in Aspergillus nidulans. J Fungi (Basel) 2023; 9:1060. [PMID: 37998866 PMCID: PMC10671992 DOI: 10.3390/jof9111060] [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: 10/04/2023] [Revised: 10/20/2023] [Accepted: 10/25/2023] [Indexed: 11/25/2023] Open
Abstract
Manganese superoxide dismutases (MnSODs) play a pivotal role in the preservation of mitochondrial integrity and function in fungi under various endogenous and exogenous stresses. Deletion of Aspergillus nidulans mnSOD/SodB increased oxidative stress sensitivity and apoptotic cell death rates as well as affected antioxidant enzyme and sterigmatocystin productions, respiration, conidiation and the stress tolerance of conidiospores. The physiological consequences of the lack of sodB were more pronounced during carbon starvation than in the presence of glucose. Lack of SodB also affected the changes in the transcriptome, recorded by high-throughput RNA sequencing, in menadione sodium bisulfite (MSB)-exposed, submerged cultures supplemented with glucose. Surprisingly, the difference between the global transcriptional changes of the ΔsodB mutant and the control strain were relatively small, indicating that the SodB-dependent maintenance of mitochondrial integrity was not essential under these experimental conditions. Owing to the outstanding physiological flexibility of the Aspergilli, certain antioxidant enzymes and endogenous antioxidants together with the reduction in mitochondrial functions compensated well for the lack of SodB. The lack of sodB reduced the growth of surface cultures more than of the submerged culture, which should be considered in future development of fungal disinfection methods.
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Affiliation(s)
- Klaudia Pákozdi
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary;
- HUN-REN–UD Fungal Stress Biology Research Group, H-4032 Debrecen, Hungary
- Doctoral School of Nutrition and Food Sciences, University of Debrecen, H-4032 Debrecen, Hungary
| | - Tamás Emri
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary;
- HUN-REN–UD Fungal Stress Biology Research Group, H-4032 Debrecen, Hungary
| | - Károly Antal
- Department of Zoology, Eszterházy Károly Catholic University, H-3300 Eger, Hungary;
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary;
- HUN-REN–UD Fungal Stress Biology Research Group, H-4032 Debrecen, Hungary
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Silva AM, Pedrini N, Pupin B, Roberts DW, Rangel DEN. Asphyxiation of Metarhizium robertsii during mycelial growth produces conidia with increased stress tolerance via increased expression of stress-related genes. Fungal Biol 2023; 127:1209-1217. [PMID: 37495310 DOI: 10.1016/j.funbio.2023.01.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 01/07/2023] [Accepted: 01/17/2023] [Indexed: 01/20/2023]
Abstract
Little is known about the impact of hypoxia and anoxia during mycelial growth on tolerance to different stress conditions of developing fungal conidia. Conidia of the insect-pathogenic fungus Metarhizium robertsii were produced on potato dextrose agar (PDA) medium under normoxia (control = normal oxygen concentrations), continuous hypoxia, and transient anoxia, as well as minimal medium under normoxia. The tolerance of the conidia produced under these different conditions was evaluated in relation to wet heat (heat stress), menadione (oxidative stress), potassium chloride (osmotic stress), UV radiation, and 4-nitroquinoline-1-oxide (=4-NQO genotoxic stress). Growth under hypoxic condition induced higher conidial tolerance of M. robertsii to menadione, KCl, and UV radiation. Transient anoxic condition induced higher conidial tolerance to KCl and UV radiation. Nutritional stress (i.e., minimal medium) induced higher conidial tolerance to heat, menadione, KCl, and UV radiation. However, neither of these treatments induced higher tolerance to 4-NQO. The gene hsp30 and hsp101 encoding a heat shock protein was upregulated under anoxic condition. In conclusion, growth under hypoxia and anoxia produced conidia with higher stress tolerances than conidia produced in normoxic condition. The nutritive stress generated by minimal medium, however, induced much higher stress tolerances. This condition also caused the highest level of gene expression in the hsp30 and hsp101 genes. Thus, the conidia produced under nutritive stress, hypoxia, and anoxia had greater adaptation to stress.
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Affiliation(s)
| | - Nicolás Pedrini
- Instituto de Investigaciones Bioquímicas de La Plata (CONICET CCT La Plata-UNLP), Universidad Nacional de La Plata, La Plata, 1900, Argentina
| | - Breno Pupin
- Centro de Ciência do Sistema Terrestre, Instituto Nacional de Pesquisa Espaciais - INPE, São José dos Campos, SP, 12227-010, Brazil
| | - Donald W Roberts
- Department of Biology, Utah State University, Logan, UT, 84322-5305, USA
| | - Drauzio E N Rangel
- Universidade Tecnológica Federal do Paraná (UTFPR), 85660-000, Dois Vizinhos, PR, Brazil.
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Bodnár V, Király A, Orosz E, Miskei M, Emri T, Karányi Z, Leiter É, de Vries RP, Pócsi I. Species-specific effects of the introduction of Aspergillus nidulans gfdB in osmophilic aspergilli. Appl Microbiol Biotechnol 2023; 107:2423-2436. [PMID: 36811707 PMCID: PMC10033484 DOI: 10.1007/s00253-023-12384-9] [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: 10/15/2022] [Revised: 01/09/2023] [Accepted: 01/11/2023] [Indexed: 02/24/2023]
Abstract
Industrial fungi need a strong environmental stress tolerance to ensure acceptable efficiency and yields. Previous studies shed light on the important role that Aspergillus nidulans gfdB, putatively encoding a NAD+-dependent glycerol-3-phosphate dehydrogenase, plays in the oxidative and cell wall integrity stress tolerance of this filamentous fungus model organism. The insertion of A. nidulans gfdB into the genome of Aspergillus glaucus strengthened the environmental stress tolerance of this xerophilic/osmophilic fungus, which may facilitate the involvement of this fungus in various industrial and environmental biotechnological processes. On the other hand, the transfer of A. nidulans gfdB to Aspergillus wentii, another promising industrial xerophilic/osmophilic fungus, resulted only in minor and sporadic improvement in environmental stress tolerance and meanwhile partially reversed osmophily. Because A. glaucus and A. wentii are phylogenetically closely related species and both fungi lack a gfdB ortholog, these results warn us that any disturbance of the stress response system of the aspergilli may elicit rather complex and even unforeseeable, species-specific physiological changes. This should be taken into consideration in any future targeted industrial strain development projects aiming at the fortification of the general stress tolerance of these fungi. KEY POINTS: • A. wentii c' gfdB strains showed minor and sporadic stress tolerance phenotypes. • The osmophily of A. wentii significantly decreased in the c' gfdB strains. • Insertion of gfdB caused species-specific phenotypes in A. wentii and A. glaucus.
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Affiliation(s)
- Veronika Bodnár
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
- Doctoral School of Nutrition and Food Sciences, University of Debrecen, Debrecen, Hungary
| | - Anita Király
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Erzsébet Orosz
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Márton Miskei
- ELRN-UD Fungal Stress Biology Research Group, Debrecen, Hungary
| | - Tamás Emri
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
- ELRN-UD Fungal Stress Biology Research Group, Debrecen, Hungary
| | - Zsolt Karányi
- Department of Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Éva Leiter
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
- ELRN-UD Fungal Stress Biology Research Group, Debrecen, Hungary
| | - Ronald P de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Utrecht, the Netherlands
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary.
- ELRN-UD Fungal Stress Biology Research Group, Debrecen, Hungary.
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Genome-Wide Gene Expression Analyses of the AtfA/AtfB-Mediated Menadione Stress Response in Aspergillus nidulans. Cells 2023; 12:cells12030463. [PMID: 36766807 PMCID: PMC9913763 DOI: 10.3390/cells12030463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/25/2023] [Accepted: 01/27/2023] [Indexed: 02/04/2023] Open
Abstract
The bZIP transcription factors (TFs) govern regulation of development, secondary metabolism, and various stress responses in filamentous fungi. In this work, we carried out genome-wide expression studies employing Illumina RNAseq to understand the roles of the two bZIP transcription factors AtfA and AtfB in Aspergillus nidulans. Comparative analyses of transcriptomes of control, ΔatfA, ΔatfB, and ΔatfAΔatfB mutant strains were performed. Dependence of a gene on AtfA (AtfB) was decided by its differential downregulation both between the reference and ΔatfA (ΔatfB) strains and between the ΔatfB (ΔatfA) and the ΔatfAΔatfB strains in vegetatively grown cells (mycelia) and asexual spores (conidia) of menadione sodium bisulfite (MSB)-treated or untreated cultures. As AtfA is the primary bZIP TF governing stress-response in A. nidulans, the number of differentially expressed genes for ΔatfA was significantly higher than for ΔatfB in both mycelial and conidial samples, and most of the AtfB-dependent genes showed AtfA dependence, too. Moreover, the low number of genes depending on AtfB but not on AtfA can be a consequence of ΔatfA leading to downregulation of atfB expression. Conidial samples showed much higher abundance of atfA and atfB mRNAs and more AtfA- and AtfB-affected genes than mycelial samples. In the presence of MSB, the number of AtfB- (but not of AtfA-) affected genes decreased markedly, which was accompanied with decreased mRNA levels of atfB in MSB-treated mycelial (reference strain) and conidial (ΔatfA mutant) samples. In mycelia, the overlap between the AtfA-dependent genes in MSB-treated and in untreated samples was low, demonstrating that distinct genes can be under AtfA control under different conditions. Carbohydrate metabolism genes were enriched in the set of AtfA-dependent genes. Among them, AtfA-dependence of glycolytic genes in conidial samples was the most notable. Levels of transcripts of certain secondary metabolitic gene clusters, such as the Emericellamide cluster, also showed AtfA-dependent regulation. Genes encoding catalase and histidine-containing phosphotransfer proteins showed AtfA-dependence under all experimental conditions. There were 23 AtfB-dependent genes that did not depend on AtfA under any of our experimental conditions. These included a putative α-glucosidase (agdB), a putative α-amylase, calA, which is involved in early conidial germination, and an alternative oxidase. In summary, in A. nidulans there is a complex interaction between the two bZIP transcription factors, where AtfA plays the primary regulatory role.
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Wang X, Zha W, Yao B, Yang L, Wang S. Genetic Interaction of Global Regulators AflatfA and AflatfB Mediating Development, Stress Response and Aflatoxins B1 Production in Aspergillus flavus. Toxins (Basel) 2022; 14:toxins14120857. [PMID: 36548754 PMCID: PMC9785671 DOI: 10.3390/toxins14120857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/01/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022] Open
Abstract
Aspergillus flavus produces carcinogenic and mutagenic aflatoxins, which cause economic losses and risk of food safety by contaminating grains, food and feed. In this study, we characterized two bZIP transcription factors, AflatfA and AflatfB, and their genetic interaction. Compared to the wild type (WT), AflatfA deletion and AflatfA and AflatfB double deletion both caused retarded vegetative growth of mycelia. Relative to WT, the AflatfA deletion strain (ΔAflatfA) and AflatfA and AflatfB double deletion strain (ΔAflatfAΔAflatfB) produced more sclerotia, whereas the AflatfB deletion strain (ΔAflatfB) produced less sclerotia. After 4 °C preservation and incubation at 50 °C, conidia viability dramatically decreased in the ΔAflatfA and ΔAflatfAΔAflatfB but ΔAflatfB mutants, whereas conidia viability of the ΔAflatfAΔAflatfB strain was higher after storage at 4 °C than in AflatfA mutant. Conidia of ΔAflatfA, ΔAflatfB and ΔAflatfAΔAflatfB strains significantly increased in sensitivity to H2O2 in comparison with WT. Compared to WT, the mycelium of ΔAflatfA and ΔAflatfB strains were more sensitive to H2O2; conversely, the ΔAflatfAΔAflatfB strain showed less sensitivity to H2O2. ΔAflatfA and ΔAflatfAΔAflatfB strains displayed less sensitivity to the osmotic reagents NaCl, KCl and Sorbitol, in comparison with WT and ΔAflatfB strains. When on YES medium and hosts corn and peanut, ΔAflatfA and ΔAflatfAΔAflatfB strains produced less aflatoxin B1 (AFB1) than ΔAflatfB, and the AFB1 yield of ΔAflatfB was higher than that of WT. When WT and mutants were inoculated on corn and peanut, the ΔAflatfA and ΔAflatfAΔAflatfB but not ΔAflatfB mutants produced less conidia than did WT. Taken together, this study reveals that AflatfA controls more cellular processes, and the function of AflatfA is stronger than that of AflatfB when of the same process is regulated, except the response to H2O2, which might result from the effect of AflatfA on the transcriptional level of AflatfB.
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Emri T, Antal K, Gila B, Jónás AP, Pócsi I. Stress Responses Elicited by Glucose Withdrawal in Aspergillus fumigatus. J Fungi (Basel) 2022; 8:jof8111226. [PMID: 36422047 PMCID: PMC9692504 DOI: 10.3390/jof8111226] [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: 10/21/2022] [Revised: 11/15/2022] [Accepted: 11/16/2022] [Indexed: 11/22/2022] Open
Abstract
Glucose is a widely used carbon source in laboratory practice to culture Aspergillus fumigatus, however, glucose availability is often low in its “natural habitats”, including the human body. We used a physiological−transcriptomical approach to reveal differences between A. fumigatus Af293 cultures incubated on glucose, glucose and peptone, peptone (carbon limitation), or without any carbon source (carbon starvation). Autolytic cell wall degradation was upregulated by both carbon starvation and limitation. The importance of autolytic cell wall degradation in the adaptation to carbon stress was also highlighted by approximately 12.4% of the A. fumigatus genomes harboring duplication of genes involved in N-acetyl glucosamine utilization. Glucose withdrawal increased redox imbalance, altered both the transcription of antioxidative enzyme genes and oxidative stress tolerance, and downregulated iron acquisition, but upregulated heme protein genes. Transcriptional activity of the Gliotoxin cluster was low in all experiments, while the Fumagillin cluster showed substantial activity both on glucose and under carbon starvation, and the Hexadehydro-astechrome cluster only on glucose. We concluded that glucose withdrawal substantially modified the physiology of A. fumigatus, including processes that contribute to virulence. This may explain the challenge of predicting the in vivo behavior of A. fumigatus based on data from glucose rich cultures.
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Affiliation(s)
- Tamás Emri
- Department of Molecular Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
- ELRN-UD Fungal Stress Biology Research Group, Egyetem tér 1, 4032 Debrecen, Hungary
- Correspondence:
| | - Károly Antal
- Department of Zoology, Eszterházy Károly Catholic University, Eszterházy tér 1, 3300 Eger, Hungary
| | - Barnabás Gila
- Department of Molecular Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
- Doctoral School of Nutrition and Food Sciences, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - Andrea P. Jónás
- Department of Molecular Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
- ELRN-UD Fungal Stress Biology Research Group, Egyetem tér 1, 4032 Debrecen, Hungary
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9
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Kocsis B, Lee MK, Yu JH, Nagy T, Daróczi L, Batta G, Pócsi I, Leiter É. Functional analysis of the bZIP-type transcription factors AtfA and AtfB in Aspergillus nidulans. Front Microbiol 2022; 13:1003709. [PMID: 36204617 PMCID: PMC9530789 DOI: 10.3389/fmicb.2022.1003709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 08/29/2022] [Indexed: 11/13/2022] Open
Abstract
Transcription factors (TFs) with the basic leucin zipper domain are key elements of the stress response pathways in filamentous fungi. In this study, we functionally characterized the two bZIP type TFs AtfA and AtfB by deletion (Δ) and overexpression (OE) of their encoding genes in all combination: ΔatfA, ΔatfB, ΔatfAΔatfB, ΔatfAatfBOE, ΔatfBatfAOE, atfAOE, atfBOE and atfAOEatfBOE in Aspergillus nidulans. Based on our previous studies, ΔatfA increased the sensitivity of the fungus to oxidative stress mediated by menadione sodium bisulfite (MSB) and tert-butylhydroperoxide (tBOOH), while ΔatfB was not sensitive to any oxidative stress generating agents, namely MSB, tBOOH and diamide at all. Contrarily, the ΔatfB mutant was sensitive to NaCl, but tolerant to sorbitol. Overexpression of atfB was able to compensate the MSB sensitivity of the ΔatfA mutant. Heavy metal stress elicited by CdCl2 reduced diameter of the atfBOE and atfAOEatfBOE mutant colonies to about 50% of control colony, while the cell wall stress generating agent CongoRed increased the tolerance of the ΔatfA mutant. When we tested the heat stress sensitivity of the asexual spores (conidiospores) of the mutants, we found that conidiospores of ΔatfAatfBOE and ΔatfBatfAOE showed nearly 100% tolerance to heat stress. Asexual development was negatively affected by ΔatfA, while atfAOE and atfAOE coupled with ΔatfB increased the number of conidiospores of the fungus approximately 150% compared to the control. Overexpression of atfB led to a 25% reduction in the number of conidiospores, but increased levels of abaA mRNA and size of conidiospores. Sexual fruiting body (cleistothecium) formation was diminished in the ΔatfA and the ΔatfAΔatfB mutants, while relatively elevated in the ΔatfB and the ΔatfBatfAOE mutants. Production of the mycotoxin sterigmatocystin (ST) was decreased to undetectable levels in the ΔatfA mutant, yet ST production was restored in the ΔatfAΔatfB mutant, suggesting that ΔatfB can suppress ST production defect caused by ΔatfA. Levels of ST were also significantly decreased in the ΔatfAatfBOE, ΔatfBatfAOE and atfAOEatfBOE mutants.
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Affiliation(s)
- Beatrix Kocsis
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
- ELRN-UD Fungal Stress Biology Research Group, Debrecen, Hungary
- Doctoral School of Pharmaceutical Sciences, University of Debrecen, Debrecen, Hungary
| | - Mi-Kyung Lee
- Biological Resource Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup-si, South Korea
| | - Jae-Hyuk Yu
- Department of Bacteriology, Food Research Institute, University of Wisconsin, Madison, WI, United States
- Department of Systems Biotechnology, Konkuk University, Seoul, South Korea
| | - Tibor Nagy
- Department of Applied Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Lajos Daróczi
- Department of Solid State Physics, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Gyula Batta
- Department of Genetics and Applied Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
- ELRN-UD Fungal Stress Biology Research Group, Debrecen, Hungary
| | - Éva Leiter
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
- ELRN-UD Fungal Stress Biology Research Group, Debrecen, Hungary
- *Correspondence: Éva Leiter,
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Cho HJ, Son SH, Chen W, Son YE, Lee I, Yu JH, Park HS. Regulation of Conidiogenesis in Aspergillus flavus. Cells 2022; 11:cells11182796. [PMID: 36139369 PMCID: PMC9497164 DOI: 10.3390/cells11182796] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 08/29/2022] [Accepted: 09/06/2022] [Indexed: 11/16/2022] Open
Abstract
Aspergillus flavus is a representative fungal species in the Aspergillus section Flavi and has been used as a model system to gain insights into fungal development and toxin production. A. flavus has several adverse effects on humans, including the production of the most carcinogenic mycotoxin aflatoxins and causing aspergillosis in immune-compromised patients. In addition, A. flavus infection of crops results in economic losses due to yield loss and aflatoxin contamination. A. flavus is a saprophytic fungus that disperses in the ecosystem mainly by producing asexual spores (conidia), which also provide long-term survival in the harsh environmental conditions. Conidia are composed of the rodlet layer, cell wall, and melanin and are produced from an asexual specialized structure called the conidiophore. The production of conidiophores is tightly regulated by various regulators, including the central regulatory cascade composed of BrlA-AbaA-WetA, the fungi-specific velvet regulators, upstream regulators, and developmental repressors. In this review, we summarize the findings of a series of recent studies related to asexual development in A. flavus and provide insights for a better understanding of other fungal species in the section Flavi.
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Affiliation(s)
- He-Jin Cho
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Korea
| | - Sung-Hun Son
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Korea
| | - Wanping Chen
- Department of Molecular Microbiology and Genetics, University of Göttingen, 37077 Göttingen, Germany
| | - Ye-Eun Son
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Korea
| | - Inhyung Lee
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul 02707, Korea
| | - Jae-Hyuk Yu
- Department of Bacteriology, University of Wisconsin, Madison, WI 53706, USA
- Department of Systems Biotechnology, Konkuk University, Seoul 05029, Korea
| | - Hee-Soo Park
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Korea
- Department of Integrative Biology, Kyungpook National University, Daegu 41566, Korea
- Correspondence: ; Tel.: +82-53-950-5751
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11
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Pérez-Pérez WD, Carrasco-Navarro U, García‑Estrada C, Kosalková K, Gutiérrez-Ruíz MC, Barrios-González J, Fierro F. bZIP transcription factors PcYap1 and PcRsmA link oxidative stress response to secondary metabolism and development in Penicillium chrysogenum. Microb Cell Fact 2022; 21:50. [PMID: 35366869 PMCID: PMC8977021 DOI: 10.1186/s12934-022-01765-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 02/27/2022] [Indexed: 01/23/2023] Open
Abstract
Abstract
Background
Reactive oxygen species (ROS) trigger different morphogenic processes in filamentous fungi and have been shown to play a role in the regulation of the biosynthesis of some secondary metabolites. Some bZIP transcription factors, such as Yap1, AtfA and AtfB, mediate resistance to oxidative stress and have a role in secondary metabolism regulation. In this work we aimed to get insight into the molecular basis of this regulation in the industrially important fungus Penicillium chrysogenum through the characterization of the role played by two effectors that mediate the oxidative stress response in development and secondary metabolism.
Results
In P. chrysogenum, penicillin biosynthesis and conidiation are stimulated by the addition of H2O2 to the culture medium, and this effect is mediated by the bZIP transcription factors PcYap1 and PcRsmA. Silencing of expression of both proteins by RNAi resulted in similar phenotypes, characterized by increased levels of ROS in the cell, reduced conidiation, higher sensitivity of conidia to H2O2 and a decrease in penicillin production. Both PcYap1 and PcRsmA are able to sense H2O2-generated ROS in vitro and change its conformation in response to this stimulus. PcYap1 and PcRsmA positively regulate the expression of brlA, the first gene of the conidiation central regulatory pathway. PcYap1 binds in vitro to a previously identified regulatory sequence in the promoter of the penicillin gene pcbAB: TTAGTAA, and to a TTACTAA sequence in the promoter of the brlA gene, whereas PcRsmA binds to the sequences TGAGACA and TTACGTAA (CRE motif) in the promoters of the pcbAB and penDE genes, respectively.
Conclusions
bZIP transcription factors PcYap1 and PcRsmA respond to the presence of H2O2-generated ROS and regulate oxidative stress response in the cell. Both proteins mediate ROS regulation of penicillin biosynthesis and conidiation by binding to specific regulatory elements in the promoters of key genes. PcYap1 is identified as the previously proposed transcription factor PTA1 (Penicillin Transcriptional Activator 1), which binds to the regulatory sequence TTAGTAA in the pcbAB gene promoter. This is the first report of a Yap1 protein directly regulating transcription of a secondary metabolism gene. A model describing the regulatory network mediated by PcYap1 and PcRsmA is proposed.
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12
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Bákány B, Yin WB, Dienes B, Nagy T, Leiter É, Emri T, Keller NP, Pócsi I. Study on the bZIP-Type Transcription Factors NapA and RsmA in the Regulation of Intracellular Reactive Species Levels and Sterigmatocystin Production of Aspergillus nidulans. Int J Mol Sci 2021; 22:11577. [PMID: 34769008 PMCID: PMC8583795 DOI: 10.3390/ijms222111577] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 10/20/2021] [Accepted: 10/22/2021] [Indexed: 11/16/2022] Open
Abstract
Basic leucine zipper (bZIP) transcription factors play a crucial role in the environmental stress response of eukaryotes. In this work, we studied the effect of gene manipulations, including both deletions and overexpressions, of two selected bZIP transcription factors, NapA and RsmA, in the oxidative stress response and sterigmatocystin production of Aspergillus nidulans. We found that NapA was important in the oxidative stress response by negatively regulating intracellular reactive species production and positively regulating catalase activities, whereas RsmA slightly negatively regulated catalase activities. Concerning sterigmatocystin production, the highest concentration was measured in the ΔrsmAΔnapA double deletion mutant, but elevated sterigmatocystin production was also found in the OErsmA OEnapA strain. Our results indicate that NapA influences sterigmatocystin production via regulating reactive species level whereas RsmA modulates toxin production independently of the redox regulation of the cells.
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Affiliation(s)
- Bernadett Bákány
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary; (B.B.); (T.E.); (I.P.)
- Doctoral School of Molecular Medicine, University of Debrecen, H-4010 Debrecen, Hungary
- Institute of Physiology, Faculty of Medicine, University of Debrecen, H-4010 Debrecen, Hungary;
| | - Wen-Bing Yin
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China;
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA;
| | - Beatrix Dienes
- Institute of Physiology, Faculty of Medicine, University of Debrecen, H-4010 Debrecen, Hungary;
| | - Tibor Nagy
- Department of Applied Chemistry, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary;
| | - Éva Leiter
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary; (B.B.); (T.E.); (I.P.)
| | - Tamás Emri
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary; (B.B.); (T.E.); (I.P.)
| | - Nancy P. Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA;
- Department of Bacteriology, University of Wisconsin, Madison, WI 53706, USA
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary; (B.B.); (T.E.); (I.P.)
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13
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Leiter É, Emri T, Pákozdi K, Hornok L, Pócsi I. The impact of bZIP Atf1ortholog global regulators in fungi. Appl Microbiol Biotechnol 2021; 105:5769-5783. [PMID: 34302199 PMCID: PMC8390427 DOI: 10.1007/s00253-021-11431-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 06/22/2021] [Accepted: 06/24/2021] [Indexed: 11/09/2022]
Abstract
Regulation of signal transduction pathways is crucial for the maintenance of cellular homeostasis and organismal development in fungi. Transcription factors are key elements of this regulatory network. The basic-region leucine zipper (bZIP) domain of the bZIP-type transcription factors is responsible for DNA binding while their leucine zipper structural motifs are suitable for dimerization with each other facilitiating the formation of homodimeric or heterodimeric bZIP proteins. This review highlights recent knowledge on the function of fungal orthologs of the Schizosaccharomyces pombe Atf1, Aspergillus nidulans AtfA, and Fusarium verticillioides FvAtfA, bZIP-type transcription factors with a special focus on pathogenic species. We demonstrate that fungal Atf1-AtfA-FvAtfA orthologs play an important role in vegetative growth, sexual and asexual development, stress response, secondary metabolite production, and virulence both in human pathogens, including Aspergillus fumigatus, Mucor circinelloides, Penicillium marneffei, and Cryptococcus neoformans and plant pathogens, like Fusarium ssp., Magnaporthe oryzae, Claviceps purpurea, Botrytis cinerea, and Verticillium dahliae. KEY POINTS: • Atf1 orthologs play crucial role in the growth and development of fungi. • Atf1 orthologs orchestrate environmental stress response of fungi. • Secondary metabolite production and virulence are coordinated by Atf1 orthologs.
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Affiliation(s)
- Éva Leiter
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, University of Debrecen, P.O. Box 63, Debrecen, H-4010, Hungary.
| | - Tamás Emri
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, University of Debrecen, P.O. Box 63, Debrecen, H-4010, Hungary
| | - Klaudia Pákozdi
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, University of Debrecen, P.O. Box 63, Debrecen, H-4010, Hungary
| | - László Hornok
- Hungarian University of Agriculture and Life Sciences, Gödöllő, Hungary
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, University of Debrecen, P.O. Box 63, Debrecen, H-4010, Hungary
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14
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Emri T, Gila B, Antal K, Fekete F, Moon H, Yu JH, Pócsi I. AtfA-Independent Adaptation to the Toxic Heavy Metal Cadmium in Aspergillus nidulans. Microorganisms 2021; 9:microorganisms9071433. [PMID: 34361869 PMCID: PMC8307709 DOI: 10.3390/microorganisms9071433] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 06/28/2021] [Accepted: 06/30/2021] [Indexed: 12/13/2022] Open
Abstract
Cadmium is an exceptionally toxic industrial and environmental pollutant classified as a human carcinogen. In order to provide insight into how we can keep our environment safe from cadmium contamination and prevent the accumulation of it in the food chain, we aim to elucidate how Aspergillus nidulans, one of the most abundant fungi in soil, survives and handles cadmium stress. As AtfA is the main transcription factor governing stress responses in A. nidulans, we examined genome-wide expression responses of wild-type and the atfA null mutant exposed to CdCl2. Both strains showed up-regulation of the crpA Cu2+/Cd2+ pump gene and AN7729 predicted to encode a putative bis(glutathionato)-cadmium transporter, and transcriptional changes associated with elevated intracellular Cys availability leading to the efficient adaptation to Cd2+. Although the deletion of atfA did not alter the cadmium tolerance of the fungus, the cadmium stress response of the mutant differed from that of a reference strain. Promoter and transcriptional analyses of the “Phospho-relay response regulator” genes suggest that the AtfA-dependent regulation of these genes can be relevant in this phenomenon. We concluded that the regulatory network of A. nidulans has a high flexibility allowing the fungus to adapt efficiently to stress both in the presence and absence of this important transcription factor.
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Affiliation(s)
- Tamás Emri
- Department of Molecular Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, 4032 Debrecen, Hungary; (B.G.); (F.F.); (I.P.)
- Correspondence:
| | - Barnabás Gila
- Department of Molecular Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, 4032 Debrecen, Hungary; (B.G.); (F.F.); (I.P.)
- Doctoral School of Nutrition and Food Sciences, University of Debrecen, 4032 Debrecen, Hungary
| | - Károly Antal
- Department of Zoology, Eszterházy Károly University, 3300 Eger, Hungary;
| | - Fanni Fekete
- Department of Molecular Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, 4032 Debrecen, Hungary; (B.G.); (F.F.); (I.P.)
| | - Heungyun Moon
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA; (H.M.); (J.-H.Y.)
| | - Jae-Hyuk Yu
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA; (H.M.); (J.-H.Y.)
- Department of Systems Biotechnology, Konkuk University, Seoul 05029, Korea
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, 4032 Debrecen, Hungary; (B.G.); (F.F.); (I.P.)
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15
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The DUG Pathway Governs Degradation of Intracellular Glutathione in Aspergillus nidulans. Appl Environ Microbiol 2021; 87:AEM.01321-20. [PMID: 33637571 DOI: 10.1128/aem.01321-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 02/10/2021] [Indexed: 12/27/2022] Open
Abstract
Glutathione (GSH) is an abundant tripeptide that plays a crucial role in shielding cellular macromolecules from various reactive oxygen and nitrogen species in fungi. Understanding GSH metabolism is of vital importance for deciphering redox regulation in these microorganisms. In the present study, to better understand the GSH metabolism in filamentous fungi, we investigated functions of the dugB and dugC genes in the model fungus Aspergillus nidulans These genes are orthologues of dug2 and dug3, which are involved in cytosolic GSH degradation in Saccharomyces cerevisiae The deletion of dugB, dugC, or both resulted in a moderate increase in the GSH content in mycelia grown on glucose, reduced conidium production, and disturbed sexual development. In agreement with these observations, transcriptome data showed that genes encoding mitogen-activated protein (MAP) kinase pathway elements (e.g., steC, sskB, hogA, and mkkA) or regulatory proteins of conidiogenesis and sexual differentiation (e.g., flbA, flbC, flbE, nosA, rosA, nsdC, and nsdD) were downregulated in the ΔdugB ΔdugC mutant. Deletion of dugB and/or dugC slowed the depletion of GSH pools during carbon starvation. It also reduced accumulation of reactive oxygen species and decreased autolytic cell wall degradation and enzyme secretion but increased sterigmatocystin formation. Transcriptome data demonstrated that enzyme secretions-in contrast to mycotoxin production-were controlled at the posttranscriptional level. We suggest that GSH connects starvation and redox regulation to each other: cells utilize GSH as a stored carbon source during starvation. The reduction of GSH content alters the redox state, activating regulatory pathways responsible for carbon starvation stress responses.IMPORTANCE Glutathione (GSH) is a widely distributed tripeptide in both eukaryotes and prokaryotes. Owing to its very low redox potential, antioxidative character, and high intracellular concentration, GSH profoundly shapes the redox status of cells. Our observations suggest that GSH metabolism and/or the redox status of cells plays a determinative role in several important aspects of fungal life, including oxidative stress defense, protein secretion, and secondary metabolite production (including mycotoxin formation), as well as sexual and asexual differentiations. We demonstrated that even a slightly elevated GSH level can substantially disturb the homeostasis of fungi. This information could be important for development of new GSH-producing strains or for any biotechnologically relevant processes where the GSH content, antioxidant capacity, or oxidative stress tolerance of a fungal strain is manipulated.
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16
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Mehta N, Baghela A. Quorum sensing-mediated inter-specific conidial anastomosis tube fusion between Colletotrichum gloeosporioides and C. siamense. IMA Fungus 2021; 12:7. [PMID: 33789776 PMCID: PMC8015167 DOI: 10.1186/s43008-021-00058-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 02/21/2021] [Indexed: 02/07/2023] Open
Abstract
Many plant pathogenic filamentous fungi undergo fusion of conidia through conidial anastomosis tubes (CATs), which is believed to facilitate horizontal gene transfer between species. We discovered a remarkable inter-specific CAT fusion between two important plant fungal pathogens Colletotrichum gloeosporioides and C. siamense. In an invitro assay, under no selection pressure, the inter-specific CAT fusion was preferred with higher frequency (25% ± 5%) than intra-specific CAT fusion (11% ± 3.6%). Different stages of CAT fusion viz. CAT induction, homing, and fusion were observed during this inter-specific CAT fusion. The CAT fusion was found to be higher in absence of nutrients and under physiological stresses. This CAT fusion involved a quorum sensing phenomenon, wherein the CAT induction was dependent on conidial density and the putative quorum sensing molecule was extractable in chloroform. Movement of nuclei, mitochondria, and lipid droplets were observed during the CAT fusion. Post CAT fusion, the resulting conidia gave rise to putative heterokaryotic progenies with variable colony characteristics as compared to their parental strains. Few heterokaryons showed variable AFLP banding pattern compared to their parental strains, thereby suggesting a possible genetic exchange between the two species through CAT fusion. The heterokaryotic progenies exhibited varied fitness under different stress conditions. Our study illustrated a possible role of inter-specific CAT fusion in generation of genetic and phenotypic diversity in these fungal pathogens.
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Affiliation(s)
- Nikita Mehta
- National Fungal Culture Collection of India (NFCCI), Biodiversity and Palaeobiology Group, MACS-Agharkar Research Institute, G.G. Agarkar Road, Pune, 411004, India.,Savitribai Phule Pune University, Pune, 411007, India
| | - Abhishek Baghela
- National Fungal Culture Collection of India (NFCCI), Biodiversity and Palaeobiology Group, MACS-Agharkar Research Institute, G.G. Agarkar Road, Pune, 411004, India. .,Savitribai Phule Pune University, Pune, 411007, India.
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17
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Badr AN, Ali HS, Abdel-Razek AG, Shehata MG, Albaridi NA. Bioactive Components of Pomegranate Oil and Their Influence on Mycotoxin Secretion. Toxins (Basel) 2020; 12:toxins12120748. [PMID: 33260849 PMCID: PMC7759867 DOI: 10.3390/toxins12120748] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 10/22/2020] [Accepted: 10/30/2020] [Indexed: 12/17/2022] Open
Abstract
Pomegranate, similar to other fruits, has juice-extraction by-products. Pomegranate seed oil (PGO) is a non-traditional oil with health benefits, rich in bioactive components. This study was aimed to assess PGO phytochemicals and their influence as bioactive components to reduce mycotoxin secretion. The encapsulation was applied in micro and nanoforms to protect the quality and enhance the efficacy of the oil. The PGO was extracted using ultrasound-assisted methods. Carotenoids, tocochromanols, sterols, phenolic, flavonoid, antioxidant, and antimicrobial activity were determined. The fatty acid profile was analyzed by the GC-MS, while mycotoxin was determined utilizing the HPLC apparatus. The toxicity and protective action of oil were examined using the hepatocytes' cell line. The resultant oil acts as oleoresin that is rich in bioactive molecules. Phenolics and antioxidant potency recorded higher values compared to traditional vegetable oils, whereas polyunsaturated fatty acids were 87.51%. The major fatty acid was conjugated punicic acid (81.29%), which has high biological effects. Application of the PGO on fungal media reduced aflatoxins secretion up to 63%, and zearalenone up to 78.5%. These results confirm the bio-functionality of oil to regulate the fungal secondary metabolites process. The PGO is a unique prospective non-traditional oil and has several functionalities in food, which achieve nutritional, antioxidant, and anti-mycotoxigenic activities.
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Affiliation(s)
- Ahmed Noah Badr
- National Research Centre, Department of Food Toxicology and Contaminants, Cairo 12622, Egypt
- Correspondence: (A.N.B.); (H.S.A.); Tel.: +2-01000-327-640 (A.N.B.); +966-56513-327-0841 (H.S.A.)
| | - Hatem Salama Ali
- Department of Food Science and Nutrition, College of Food Science and Agriculture, King Saud University, Riyadh 11451, Saudi Arabia
- National Research Centre, Department of Food Technology, Cairo 12622, Egypt
- Correspondence: (A.N.B.); (H.S.A.); Tel.: +2-01000-327-640 (A.N.B.); +966-56513-327-0841 (H.S.A.)
| | | | - Mohamed Gamal Shehata
- Department of Food Technology, Arid Lands Cultivation Research Institute, the City of Scientific Research and Technological Application (SRTA-City), New Borg El-Arab 21934, Alexandria, Egypt;
| | - Najla A. Albaridi
- Department of Physical Sport Science, Nutrition and Food Science, Princess Nourah Bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia;
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Two New Aspergillus flavus Reference Genomes Reveal a Large Insertion Potentially Contributing to Isolate Stress Tolerance and Aflatoxin Production. G3-GENES GENOMES GENETICS 2020; 10:3515-3531. [PMID: 32817124 PMCID: PMC7534430 DOI: 10.1534/g3.120.401405] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Efforts in genome sequencing in the Aspergillus genus have led to the development of quality reference genomes for several important species including A. nidulans, A. fumigatus, and A. oryzae However, less progress has been made for A. flavus As part of the effort of the USDA-ARS Annual Aflatoxin Workshop Fungal Genome Project, the isolate NRRL3357 was sequenced and resulted in a scaffold-level genome released in 2005. Our goal has been biologically driven, focusing on two areas: isolate variation in aflatoxin production and drought stress exacerbating aflatoxin production by A. flavus Therefore, we developed two reference pseudomolecule genome assemblies derived from chromosome arms for two isolates: AF13, a MAT1-2, highly stress tolerant, and highly aflatoxigenic isolate; and NRRL3357, a MAT1-1, less stress tolerant, and moderate aflatoxin producer in comparison to AF13. Here, we report these two reference-grade assemblies for these isolates through a combination of PacBio long-read sequencing and optical mapping, and coupled them with comparative, functional, and phylogenetic analyses. This analysis resulted in the identification of 153 and 45 unique genes in AF13 and NRRL3357, respectively. We also confirmed the presence of a unique 310 Kb insertion in AF13 containing 60 genes. Analysis of this insertion revealed the presence of a bZIP transcription factor, named atfC, which may contribute to isolate pathogenicity and stress tolerance. Phylogenomic analyses comparing these and other available assemblies also suggest that the species complex of A. flavus is polyphyletic.
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19
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Szabó Z, Pákozdi K, Murvai K, Pusztahelyi T, Kecskeméti Á, Gáspár A, Logrieco AF, Emri T, Ádám AL, Leiter É, Hornok L, Pócsi I. FvatfA regulates growth, stress tolerance as well as mycotoxin and pigment productions in Fusarium verticillioides. Appl Microbiol Biotechnol 2020; 104:7879-7899. [PMID: 32719911 PMCID: PMC7447684 DOI: 10.1007/s00253-020-10717-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 05/22/2020] [Accepted: 06/01/2020] [Indexed: 01/22/2023]
Abstract
FvatfA from the maize pathogen Fusarium verticillioides putatively encodes the Aspergillus nidulans AtfA and Schizasaccharomyces pombe Atf1 orthologous bZIP-type transcription factor, FvAtfA. In this study, a ΔFvatfA deletion mutant was constructed and then genetically complemented with the fully functional FvatfA gene. Comparing phenotypic features of the wild-type parental, the deletion mutant and the restored strains shed light on the versatile regulatory functions played by FvAtfA in (i) the maintenance of vegetative growth on Czapek-Dox and Potato Dextrose agars and invasive growth on unwounded tomato fruits, (ii) the preservation of conidiospore yield and size, (iii) the orchestration of oxidative (H2O2, menadione sodium bisulphite) and cell wall integrity (Congo Red) stress defences and (iv) the regulation of mycotoxin (fumonisins) and pigment (bikaverin, carotenoid) productions. Expression of selected biosynthetic genes both in the fumonisin (fum1, fum8) and the carotenoid (carRA, carB) pathways were down-regulated in the ΔFvatfA strain resulting in defected fumonisin production and considerably decreased carotenoid yields. The expression of bik1, encoding the polyketide synthase needed in bikaverin biosynthesis, was not up-regulated by the deletion of FvatfA meanwhile the ΔFvatfA strain produced approximately ten times more bikaverin than the wild-type or the genetically complemented strains. The abolishment of fumonisin production of the ΔFvatfA strain may lead to the development of new-type, biology-based mycotoxin control strategies. The novel information gained on the regulation of pigment production by this fungus can be interesting for experts working on new, Fusarium-based biomass and pigment production technologies.Key points • FvatfA regulates vegetative and invasive growths of F. verticillioides. • FvatfA also orchestrates oxidative and cell wall integrity stress defenses. • The ΔFvatfA mutant was deficient in fumonisin production. • FvatfA deletion resulted in decreased carotenoid and increased bikaverin yields. |
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Affiliation(s)
- Zsuzsa Szabó
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary.,Doctoral School of Biological Sciences, Faculty of Agricultural and Environmental Sciences, Szent István University, Gödöllő, Hungary
| | - Klaudia Pákozdi
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary.,Doctoral School of Nutrition and Food Sciences, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Katalin Murvai
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Tünde Pusztahelyi
- Central Laboratory of Agricultural and Food Products, Faculty of Agricultural and Food Sciences and Environmental Management, University of Debrecen, Debrecen, Hungary
| | - Ádám Kecskeméti
- Department of Inorganic and Analytical Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Attila Gáspár
- Department of Inorganic and Analytical Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | | | - Tamás Emri
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Attila L Ádám
- Plant Protection Institute, Centre for Agricultural Research, Budapest, Hungary
| | - Éva Leiter
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - László Hornok
- Faculty of Agricultural and Environmental Sciences, Szent István University, Gödöllő, Hungary
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary.
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20
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Király A, Szabó IG, Emri T, Leiter É, Pócsi I. Supplementation of Aspergillus glaucus with gfdB gene encoding a glycerol 3-phosphate dehydrogenase in Aspergillus nidulans. J Basic Microbiol 2020; 60:691-698. [PMID: 32510634 DOI: 10.1002/jobm.202000067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 05/19/2020] [Accepted: 05/23/2020] [Indexed: 11/09/2022]
Abstract
In Aspergillus nidulans, there are two putative glycerol 3-phosphate dehydrogenases encoded by the genes gfdA and gfdB, while the genome of the osmophilic Aspergillus glaucus harbors only the ortholog of the A. nidulans gfdA gene. Our aim was to insert the gfdB gene into the genome of A. glaucus, and we reached this goal with the adaptation of the Agrobacterium tumefaciens-mediated transformation method. We tested the growth of the gfdB-complemented A. glaucus strains on a medium containing 2 mol l-1 sorbitol in the presence of oxidative stress generating agents such as tert-butyl hydroperoxide, H2 O2 , menadione sodium bisulfite, as well as the cell wall integrity stress-inducing agent Congo Red and the heavy metal stress eliciting CdCl2 . The growth of the complemented strains was significantly higher than that of the wild-type strain on media supplemented with these stress generating agents. The A. nidulans ΔgfdB mutant was also examined under the same conditions and resulted in a considerably lower growth than that of the control strain in all stress exposure experiments. Our results shed light on the fact that the gfdB gene from A. nidulans was also involved in the stress responses of the complemented A. glaucus strains supporting our hypothesis on the antioxidant function of GfdB in the Aspergilli. Nevertheless, the osmotolerant nature of A. glaucus could not be explained by the lack of the gfdB gene in A. glaucus, as we hypothesized earlier.
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Affiliation(s)
- Anita Király
- Pál Juhász-Nagy Doctoral School of Biology and Environmental Sciences, University of Debrecen, Debrecen, Hungary
| | - Ivett G Szabó
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Tamás Emri
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Éva Leiter
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
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21
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Boczonádi I, Török Z, Jakab Á, Kónya G, Gyurcsó K, Baranyai E, Szoboszlai Z, Döncző B, Fábián I, Leiter É, Lee MK, Csernoch L, Yu JH, Kertész Z, Emri T, Pócsi I. Increased Cd 2+ biosorption capability of Aspergillus nidulans elicited by crpA deletion. J Basic Microbiol 2020; 60:574-584. [PMID: 32449553 DOI: 10.1002/jobm.202000112] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/27/2020] [Accepted: 04/20/2020] [Indexed: 12/15/2022]
Abstract
The P-type ATPase CrpA is an important Cu2+ /Cd2+ pump in the Aspergilli, significantly contributing to the heavy metal stress tolerance of these ascomycetous fungi. As expected, the deletion of crpA resulted in Cu2+ /Cd2+ -sensitive phenotypes in Aspergillus nidulans on stress agar plates inoculated with conidia. Nevertheless, paradoxical growth stimulations were observed with the ΔcrpA strain in both standard Cu2+ stress agar plate experiments and cellophane colony harvest (CCH) cultures, when exposed to Cd2+ . These observations reflect efficient compensatory mechanisms for the loss of CrpA operating under these experimental conditions. It is remarkable that the ΔcrpA strain showed a 2.7 times higher Cd biosorption capacity in CCH cultures, which may facilitate the development of new, fungal biomass-based bioremediation technologies to extract harmful Cd2+ ions from the environment. The nullification of crpA also significantly changed the spatial distribution of Cu and Cd in CCH cultures, as demonstrated by the combined particle-induced X-ray emission and scanning transmission ion microscopy technique. Most important, the centers of gravity for Cu and Cd accumulations of the ΔcrpA colonies shifted toward the older regions as compared with wild-type surface cultures.
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Affiliation(s)
- Imre Boczonádi
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary.,Juhász-Nagy Pál Doctoral School, University of Debrecen, Debrecen, Hungary
| | - Zsófia Török
- Laboratory for Heritage Science, Institute for Nuclear Research, Hungarian Academy of Sciences (ATOMKI), Debrecen, Hungary
| | - Ágnes Jakab
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Gábor Kónya
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Klaudia Gyurcsó
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Edina Baranyai
- Department of Inorganic and Analytical Chemistry, Agilent Atomic Spectroscopy Partner Laboratory, University of Debrecen, Debrecen, Hungary
| | - Zoltán Szoboszlai
- Laboratory for Heritage Science, Institute for Nuclear Research, Hungarian Academy of Sciences (ATOMKI), Debrecen, Hungary
| | - Boglárka Döncző
- Laboratory for Heritage Science, Institute for Nuclear Research, Hungarian Academy of Sciences (ATOMKI), Debrecen, Hungary
| | - István Fábián
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Debrecen, Hungary.,MTA-DE Redox and Homogeneous Catalytic Reaction Mechanisms Research Group, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Éva Leiter
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Mi-Kyung Lee
- Biological Resource Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejon, Republic of Korea
| | - László Csernoch
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Jae-Hyuk Yu
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin.,Department of Systems Biotechnology, Konkuk University, Seoul, Republic of Korea
| | - Zsófia Kertész
- Laboratory for Heritage Science, Institute for Nuclear Research, Hungarian Academy of Sciences (ATOMKI), Debrecen, Hungary
| | - Tamás Emri
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
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22
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Brown AJP, Larcombe DE, Pradhan A. Thoughts on the evolution of Core Environmental Responses in yeasts. Fungal Biol 2020; 124:475-481. [PMID: 32389310 PMCID: PMC7232023 DOI: 10.1016/j.funbio.2020.01.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 01/07/2020] [Accepted: 01/09/2020] [Indexed: 12/18/2022]
Abstract
The model yeasts, Saccharomyces cerevisiae and Schizosaccharomyces pombe, display Core Environmental Responses (CERs) that include the induction of a core set of stress genes in response to diverse environmental stresses. CERs underlie the phenomenon of stress cross-protection, whereby exposure to one type of stress can provide protection against subsequent exposure to a second type of stress. CERs have probably arisen through the accumulation, over evolutionary time, of protective anticipatory responses (“adaptive prediction”). CERs have been observed in other evolutionarily divergent fungi but, interestingly, not in the pathogenic yeast, Candida albicans. We argue that this is because we have not looked in the right place. In response to specific host inputs, C. albicans does activate anticipatory responses that protect it against impending attack from the immune system. Therefore, we suggest that C. albicans has evolved a CER that reflects the environmental challenges it faces in host niches. We review Core Environmental Responses (CERs) in domesticated and pathogenic yeasts. CERs probably evolved through the accumulation of protective anticipatory responses. Evolutionarily diverse yeasts display CERs, but the pathogen, Candida albicans, does not. C. albicans has evolved an alternative CER that protects against immune clearance. This has implications for the investigation of CERs in other fungi.
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Affiliation(s)
- Alistair J P Brown
- MRC Centre for Medical Mycology, University of Exeter, Department of Biosciences, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK.
| | - Daniel E Larcombe
- MRC Centre for Medical Mycology, University of Exeter, Department of Biosciences, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK
| | - Arnab Pradhan
- MRC Centre for Medical Mycology, University of Exeter, Department of Biosciences, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK
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23
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Antal K, Gila BC, Pócsi I, Emri T. General stress response or adaptation to rapid growth in Aspergillus nidulans? Fungal Biol 2019; 124:376-386. [PMID: 32389300 DOI: 10.1016/j.funbio.2019.10.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 10/14/2019] [Accepted: 10/18/2019] [Indexed: 11/29/2022]
Abstract
Genome-wide transcriptional changes in Aspergillus nidulans induced by nine different stress conditions were evaluated to reveal the general environmental stress response gene set showing unidirectional expressional changes under various types of stress. Clustering the genes by their transcriptional changes was a useful technique for identifying large groups of co-regulated genes. Altogether, 1642 co-upregulated and 3916 co-downregulated genes were identified. Nevertheless, the co-regulated genes describe the difference between the transcriptomes recorded under the stress conditions tested and one chosen reference culture condition which is designated as the "unstressed" condition. Obviously, the corresponding transcriptional differences may be attributed to either the general stress response or the reference condition. Accordingly, reduced growth and increased transcription of certain antioxidative enzymes observed under stress may be interpreted as elements of the general stress response or as a feature of the "optimal growth" reference condition and decreased antioxidative protection due to "rapid growth" stress. Reversing the many to one comparison underlying the identification of co-regulated gene sets allows the same procedure to highlight changes under a single condition with respect to a set of other "background" conditions. As an example, we compared menadione treatment to our other conditions and identified downregulation of endoplasmic reticulum dependent processes and upregulation of iron-sulfur cluster assembly as well as glutathione-S-transferase genes as changes characteristic of MSB-treated cultures. Deletion of the atfA gene markedly altered the co-regulated gene sets primarily by changing the reference transcriptome; not by changing the stress responsiveness of genes. The functional characterization of AtfA-dependent co-regulated genes demonstrated the involvement of AtfA in the regulation of both vegetative growth and conidiogenesis in untreated cultures. Our data also suggested that the diverse effects of atfA gene deletion on the transcriptome under different stress conditions were the consequence of the altered transcription of several phosphorelay signal transduction system genes, including fphA, nikA, phkA, srrB, srrC, sskA and tcsB. Hopefully, this study will draw further attention to the importance of the proper selection of reference cultures in fungal transcriptomics studies especially when elements of specific stress responses are mapped.
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Affiliation(s)
- Károly Antal
- Department of Zoology, Eszterházy Károly University, Eszterházy tér 1, Eger, 3300, Hungary
| | - Barnabás Cs Gila
- Department of Molecular Biotechnology and Microbiology, University of Debrecen, Egyetem tér 1, Debrecen, 4032, Hungary; University of Debrecen, Doctoral School of Nutrition and Food Sciences, Egyetem tér 1, Debrecen, 4032, Hungary
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, University of Debrecen, Egyetem tér 1, Debrecen, 4032, Hungary
| | - Tamás Emri
- Department of Molecular Biotechnology and Microbiology, University of Debrecen, Egyetem tér 1, Debrecen, 4032, Hungary.
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24
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Hackley RK, Schmid AK. Global Transcriptional Programs in Archaea Share Features with the Eukaryotic Environmental Stress Response. J Mol Biol 2019; 431:4147-4166. [PMID: 31437442 PMCID: PMC7419163 DOI: 10.1016/j.jmb.2019.07.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 07/18/2019] [Accepted: 07/18/2019] [Indexed: 01/06/2023]
Abstract
The environmental stress response (ESR), a global transcriptional program originally identified in yeast, is characterized by a rapid and transient transcriptional response composed of large, oppositely regulated gene clusters. Genes induced during the ESR encode core components of stress tolerance, macromolecular repair, and maintenance of homeostasis. In this review, we investigate the possibility for conservation of the ESR across the eukaryotic and archaeal domains of life. We first re-analyze existing transcriptomics data sets to illustrate that a similar transcriptional response is identifiable in Halobacterium salinarum, an archaeal model organism. To substantiate the archaeal ESR, we calculated gene-by-gene correlations, gene function enrichment, and comparison of temporal dynamics. We note reported examples of variation in the ESR across fungi, then synthesize high-level trends present in expression data of other archaeal species. In particular, we emphasize the need for additional high-throughput time series expression data to further characterize stress-responsive transcriptional programs in the Archaea. Together, this review explores an open question regarding features of global transcriptional stress response programs shared across domains of life.
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Affiliation(s)
- Rylee K Hackley
- Department of Biology, Duke University, Durham, NC 27708, USA; University Program in Genetics and Genomics, Duke University, Durham, NC 27708, USA
| | - Amy K Schmid
- Department of Biology, Duke University, Durham, NC 27708, USA; University Program in Genetics and Genomics, Duke University, Durham, NC 27708, USA; Center for Genomics and Computational Biology, Duke University, Durham, NC 27708, USA.
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25
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Shao H, Tu Y, Wang Y, Jiang C, Ma L, Hu Z, Wang J, Zeng B, He B. Oxidative Stress Response of Aspergillus oryzae Induced by Hydrogen Peroxide and Menadione Sodium Bisulfite. Microorganisms 2019; 7:E225. [PMID: 31366149 PMCID: PMC6724031 DOI: 10.3390/microorganisms7080225] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 07/18/2019] [Accepted: 07/29/2019] [Indexed: 12/27/2022] Open
Abstract
Oxidative stress response protects organisms from deleterious effects of reactive oxygen species (ROS), which can damage cellular components and cause disturbance of the cellular homeostasis. Although the defensive biochemical mechanisms have been extensively studied in yeast and other filamentous fungi, little information is available about Aspergillus oryzae. We investigated the effect of two oxidant agents (menadione sodium bisulfite, MSB, and hydrogen peroxide, H2O2) on cellular growth and antioxidant enzyme induction in A. oryzae. Results indicated severe inhibition of biomass and conidia production when high concentration of oxidants was used. Transcriptomic analysis showed an up-regulated expression of genes involved in oxidoreduction, such as catalase, glutathione peroxidase, and superoxide dismutase. In addition, it was observed that oxidative stress stimuli enhanced the expression of Yap1 and Skn7 transcription factors. Further, metabolomic analysis showed that glutathione content was increased in the oxidative treatments when compared with the control. Moreover, the content of unsaturated fatty acid decreased with oxidative treatment accompanying with the down-regulated expression of genes involved in linoleic acid biosynthesis. This study provided a global transcriptome characterization of oxidative stress response in A. oryzae, and can offer multiple target genes for oxidative tolerance improvement via genetic engineering.
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Affiliation(s)
- Huanhuan Shao
- Jiangxi Key Laboratory of Bioprocess Engineering and Co-Innovation Center for In-vitro Diagnostic Reagents and Devices of Jiangxi Province, College of Life Sciences, Jiangxi Science & Technology Normal University, Nanchang 330013, China
- College of Life Sciences, Sichuan Normal University, Chengdu 610101, China
| | - Yayi Tu
- Jiangxi Key Laboratory of Bioprocess Engineering and Co-Innovation Center for In-vitro Diagnostic Reagents and Devices of Jiangxi Province, College of Life Sciences, Jiangxi Science & Technology Normal University, Nanchang 330013, China
| | - Yijing Wang
- Jiangxi Key Laboratory of Bioprocess Engineering and Co-Innovation Center for In-vitro Diagnostic Reagents and Devices of Jiangxi Province, College of Life Sciences, Jiangxi Science & Technology Normal University, Nanchang 330013, China
| | - Chunmiao Jiang
- Jiangxi Key Laboratory of Bioprocess Engineering and Co-Innovation Center for In-vitro Diagnostic Reagents and Devices of Jiangxi Province, College of Life Sciences, Jiangxi Science & Technology Normal University, Nanchang 330013, China
| | - Long Ma
- Jiangxi Key Laboratory of Bioprocess Engineering and Co-Innovation Center for In-vitro Diagnostic Reagents and Devices of Jiangxi Province, College of Life Sciences, Jiangxi Science & Technology Normal University, Nanchang 330013, China
| | - Zhihong Hu
- Jiangxi Key Laboratory of Bioprocess Engineering and Co-Innovation Center for In-vitro Diagnostic Reagents and Devices of Jiangxi Province, College of Life Sciences, Jiangxi Science & Technology Normal University, Nanchang 330013, China
| | - Jiangfan Wang
- Jiangxi Key Laboratory of Bioprocess Engineering and Co-Innovation Center for In-vitro Diagnostic Reagents and Devices of Jiangxi Province, College of Life Sciences, Jiangxi Science & Technology Normal University, Nanchang 330013, China
| | - Bin Zeng
- Jiangxi Key Laboratory of Bioprocess Engineering and Co-Innovation Center for In-vitro Diagnostic Reagents and Devices of Jiangxi Province, College of Life Sciences, Jiangxi Science & Technology Normal University, Nanchang 330013, China.
| | - Bin He
- Jiangxi Key Laboratory of Bioprocess Engineering and Co-Innovation Center for In-vitro Diagnostic Reagents and Devices of Jiangxi Province, College of Life Sciences, Jiangxi Science & Technology Normal University, Nanchang 330013, China.
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26
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Orosz E, van de Wiele N, Emri T, Zhou M, Robert V, de Vries RP, Pócsi I. Fungal Stress Database (FSD)--a repository of fungal stress physiological data. DATABASE-THE JOURNAL OF BIOLOGICAL DATABASES AND CURATION 2018; 2018:4855292. [PMID: 29688353 PMCID: PMC5810435 DOI: 10.1093/database/bay009] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 01/15/2018] [Indexed: 01/19/2023]
Abstract
The construction of the Fungal Stress Database (FSD) was initiated and fueled by two major goals. At first, some outstandingly important groups of filamentous fungi including the aspergilli possess remarkable capabilities to adapt to a wide spectrum of environmental stress conditions but the underlying mechanisms of this stress tolerance have remained yet to be elucidated. Furthermore, the lack of any satisfactory interlaboratory standardization of stress assays, e.g. the widely used stress agar plate experiments, often hinders the direct comparison and discussion of stress physiological data gained for various fungal species by different research groups. In order to overcome these difficulties and to promote multilevel, e.g. combined comparative physiology-based and comparative genomics-based, stress research in filamentous fungi, we constructed FSD, which currently stores 1412 photos taken on Aspergillus colonies grown under precisely defined stress conditions. This study involved altogether 18 Aspergillus strains representing 17 species with two different strains for Aspergillus niger and covered six different stress conditions. Stress treatments were selected considering the frequency of various stress tolerance studies published in the last decade in the aspergilli and included oxidative (H2O2, menadione sodium bisulphite), high-osmolarity (NaCl, sorbitol), cell wall integrity (Congo Red) and heavy metal (CdCl2) stress exposures. In the future, we would like to expand this database to accommodate further fungal species and stress treatments. URL: http://www.fung-stress.org/
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Affiliation(s)
- Erzsébet Orosz
- Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary.,Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, CT 3584 Utrecht, The Netherlands
| | - Nathalie van de Wiele
- Bioinformatics Group, Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, CT 3584 Utrecht, The Netherlands
| | - Tamás Emri
- Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
| | - Miaomiao Zhou
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, CT 3584 Utrecht, The Netherlands
| | - Vincent Robert
- Bioinformatics Group, Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, CT 3584 Utrecht, The Netherlands
| | - Ronald P de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, CT 3584 Utrecht, The Netherlands
| | - István Pócsi
- Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
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Velvet domain protein VosA represses the zinc cluster transcription factor SclB regulatory network for Aspergillus nidulans asexual development, oxidative stress response and secondary metabolism. PLoS Genet 2018; 14:e1007511. [PMID: 30044771 PMCID: PMC6078315 DOI: 10.1371/journal.pgen.1007511] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 08/06/2018] [Accepted: 06/22/2018] [Indexed: 12/30/2022] Open
Abstract
The NF-κB-like velvet domain protein VosA (viability of spores) binds to more than 1,500 promoter sequences in the filamentous fungus Aspergillus nidulans. VosA inhibits premature induction of the developmental activator gene brlA, which promotes asexual spore formation in response to environmental cues as light. VosA represses a novel genetic network controlled by the sclB gene. SclB function is antagonistic to VosA, because it induces the expression of early activator genes of asexual differentiation as flbC and flbD as well as brlA. The SclB controlled network promotes asexual development and spore viability, but is independent of the fungal light control. SclB interactions with the RcoA transcriptional repressor subunit suggest additional inhibitory functions on transcription. SclB links asexual spore formation to the synthesis of secondary metabolites including emericellamides, austinol as well as dehydroaustinol and activates the oxidative stress response of the fungus. The fungal VosA-SclB regulatory system of transcription includes a VosA control of the sclB promoter, common and opposite VosA and SclB control functions of fungal development and several additional regulatory genes. The relationship between VosA and SclB illustrates the presence of a convoluted surveillance apparatus of transcriptional control, which is required for accurate fungal development and the linkage to the appropriate secondary metabolism. Velvet domain proteins of filamentous fungi are structurally similar to Rel-homology domains of mammalian NF-κB proteins. Velvet and NF-κB proteins control regulatory circuits of downstream transcriptional networks for cellular differentiation, survival and stress responses. Velvet proteins interconnect developmental programs with secondary metabolism in fungi. The velvet protein VosA binds to more than ten percent of the Aspergillus nidulans promoters and is important for the spatial and temporal control of asexual spore formation from conidiophores. A novel VosA-dependent genetic network has been identified and is controlled by the zinc cluster protein SclB. Although zinc cluster proteins constitute one of the most abundant classes of transcription factors in fungi, only a small amount is characterized. SclB is a repression target of VosA and both transcription factors are part of a mutual control in the timely adjusted choreography of asexual sporulation in A. nidulans. SclB acts at the interphase of asexual development and secondary metabolism and interconnects both programs with an adequate oxidative stress response. This study underlines the complexity of different hierarchical levels of the fungal velvet protein transcriptional network for developmental programs and interconnected secondary metabolism.
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28
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Kurucz V, Krüger T, Antal K, Dietl AM, Haas H, Pócsi I, Kniemeyer O, Emri T. Additional oxidative stress reroutes the global response of Aspergillus fumigatus to iron depletion. BMC Genomics 2018; 19:357. [PMID: 29747589 PMCID: PMC5946477 DOI: 10.1186/s12864-018-4730-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 04/26/2018] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Aspergillus fumigatus has to cope with a combination of several stress types while colonizing the human body. A functional interplay between these different stress responses can increase the chances of survival for this opportunistic human pathogen during the invasion of its host. In this study, we shed light on how the H2O2-induced oxidative stress response depends on the iron available to this filamentous fungus, using transcriptomic analysis, proteomic profiles, and growth assays. RESULTS The applied H2O2 treatment, which induced only a negligible stress response in iron-replete cultures, deleteriously affected the fungus under iron deprivation. The majority of stress-induced changes in gene and protein expression was not predictable from data coming from individual stress exposure and was only characteristic for the combination of oxidative stress plus iron deprivation. Our experimental data suggest that the physiological effects of combined stresses and the survival of the fungus highly depend on fragile balances between economization of iron and production of essential iron-containing proteins. One observed strategy was the overproduction of iron-independent antioxidant proteins to combat oxidative stress during iron deprivation, e.g. the upregulation of superoxide dismutase Sod1, the thioredoxin reductase Trr1, and the thioredoxin orthologue Afu5g11320. On the other hand, oxidative stress induction overruled iron deprivation-mediated repression of several genes. In agreement with the gene expression data, growth studies underlined that in A. fumigatus iron deprivation aggravates oxidative stress susceptibility. CONCLUSIONS Our data demonstrate that studying stress responses under separate single stress conditions is not sufficient to understand how A. fumigatus adapts in a complex and hostile habitat like the human body. The combinatorial stress of iron depletion and hydrogen peroxide caused clear non-additive effects upon the stress response of A. fumigatus. Our data further supported the view that the ability of A. fumigatus to cause diseases in humans strongly depends on its fitness attributes and less on specific virulence factors. In summary, A. fumigatus is able to mount and coordinate complex and efficient responses to combined stresses like iron deprivation plus H2O2-induced oxidative stress, which are exploited by immune cells to kill fungal pathogens.
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Affiliation(s)
- Vivien Kurucz
- Department of Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, Debrecen, H-4032 Hungary
| | - Thomas Krüger
- Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), 07745 Jena, Germany
| | - Károly Antal
- Department of Zoology, Faculty of Sciences, Eszterházy Károly University, Eszterházy tér 1, Eger, H-3300 Hungary
| | - Anna-Maria Dietl
- Division of Molecular Biology, Biocenter, Medical University of Innsbruck, A6020 Innsbruck, Austria
| | - Hubertus Haas
- Division of Molecular Biology, Biocenter, Medical University of Innsbruck, A6020 Innsbruck, Austria
| | - István Pócsi
- Department of Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, Debrecen, H-4032 Hungary
| | - Olaf Kniemeyer
- Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), 07745 Jena, Germany
| | - Tamás Emri
- Department of Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, Egyetem tér 1, Debrecen, H-4032 Hungary
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Ballard E, Melchers WJG, Zoll J, Brown AJP, Verweij PE, Warris A. In-host microevolution of Aspergillus fumigatus: A phenotypic and genotypic analysis. Fungal Genet Biol 2018; 113:1-13. [PMID: 29477713 PMCID: PMC5883321 DOI: 10.1016/j.fgb.2018.02.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 02/06/2018] [Accepted: 02/21/2018] [Indexed: 01/23/2023]
Abstract
In order to survive, Aspergillus fumigatus must adapt to specific niche environments. Adaptation to the human host includes modifications facilitating persistent colonisation and the development of azole resistance. The aim of this study is to advance understanding of the genetic and physiological adaptation of A. fumigatus in patients during infection and treatment. Thirteen A. fumigatus strains were isolated from a single chronic granulomatous disease patient suffering from persistent and recurrent invasive aspergillosis over a period of 2 years. All strains had identical microsatellite genotypes and were considered isogenic. Whole genome comparisons identified 248 non-synonymous single nucleotide polymorphisms. These non-synonymous mutations have potential to play a role in in-host adaptation. The first 2 strains isolated were azole susceptible, whereas later isolates were itraconazole, voriconazole and/or posaconazole resistant. Growth assays in the presence and absence of various antifungal stressors highlighted minor changes in growth rate and stress resistance, with exception of one isolate showing a significant growth defect. Poor conidiation was observed in later isolates. In certain drug resistant isolates conidiation was restored in the presence of itraconazole. Differences in virulence were observed as demonstrated in a Galleria mellonella infection model. We conclude that the microevolution of A. fumigatus in this patient has driven the emergence of both Cyp51A-independent and Cyp51A-dependent, azole resistance mechanisms, and additional phenotypes that are likely to have promoted fungal persistence.
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Affiliation(s)
- Eloise Ballard
- Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Aberdeen Fungal Group, Institute of Medical Sciences, Aberdeen, UK
| | - Willem J G Melchers
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands; Centre of Expertise in Mycology, Radboudumc/CWZ, Nijmegen, The Netherlands
| | - Jan Zoll
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands; Centre of Expertise in Mycology, Radboudumc/CWZ, Nijmegen, The Netherlands
| | - Alistair J P Brown
- Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Aberdeen Fungal Group, Institute of Medical Sciences, Aberdeen, UK
| | - Paul E Verweij
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands; Centre of Expertise in Mycology, Radboudumc/CWZ, Nijmegen, The Netherlands
| | - Adilia Warris
- Medical Research Council Centre for Medical Mycology at the University of Aberdeen, Aberdeen Fungal Group, Institute of Medical Sciences, Aberdeen, UK.
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Hanano A, Alkara M, Almousally I, Shaban M, Rahman F, Hassan M, Murphy DJ. The Peroxygenase Activity of the Aspergillus flavus Caleosin, AfPXG, Modulates the Biosynthesis of Aflatoxins and Their Trafficking and Extracellular Secretion via Lipid Droplets. Front Microbiol 2018; 9:158. [PMID: 29467750 PMCID: PMC5808235 DOI: 10.3389/fmicb.2018.00158] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 01/23/2018] [Indexed: 11/29/2022] Open
Abstract
Aflatoxins (AF) are highly detrimental to human and animal health. We recently demonstrated that the Aspergillus flavus caleosin, AfPXG, had peroxygenase activity and mediated fungal development and AF accumulation. We now report the characterization of an AfPXG-deficient line using reference strain NRRL3357. The resulting fungal phenotype included a severe decrease in mycelium growth, failure to sporulate, and reduced AF production. Increasing cellular oxidative status by administration of hydrogen peroxide and cumene hydroperoxide did not restore the AfPXG-deficient phenotype, which suggests that AfPXG-deficiency is not directly related to oxidative stress. To investigate possible alternative roles of AfPXG, a gain of function approach was used to overexpress AfPXG, with the reporter gene Gfp, in an AfPXG-deficient line, termed AfPXG+ . The resulting phenotype included elevated numbers of stable lipid droplets (LDs) plus enhanced AF production. Highly purified LDs from AfPXG+ cultures sequestered AF and this ability was positively correlated with overall LD number. Site-specific mutagenesis of AfPXG to delete Histidine 85 (AfPXGHis85), a residue essential for its catalytic activity, or deletion of the putative LD targeting domain (AfPXGD126-140), showed that AfPXG-peroxygenase activity was required for AF biosynthesis and that integration of AF into LDs was required for their export via a LD-dependent pathway. Ectopic expression in fungal cells of the plant LD-associated protein, oleosin, also resulted in both additional LD accumulation and enhanced AF secretion. These results suggest that both fungal LDs and their associated caleosin proteins are intimately involved in the biosynthesis, trafficking, and secretion of AF.
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Affiliation(s)
- Abdulsamie Hanano
- Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria, Damascus, Syria
| | - Mari Alkara
- Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria, Damascus, Syria
| | - Ibrahem Almousally
- Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria, Damascus, Syria
| | - Mouhnad Shaban
- Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria, Damascus, Syria
| | - Farzana Rahman
- Genomics and Computational Biology Research Group, University of South Wales, Pontypridd, United Kingdom
| | - Mehedi Hassan
- Genomics and Computational Biology Research Group, University of South Wales, Pontypridd, United Kingdom
| | - Denis J. Murphy
- Genomics and Computational Biology Research Group, University of South Wales, Pontypridd, United Kingdom
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Hu Y, Qin Y, Liu G. Collection and Curation of Transcriptional Regulatory Interactions in Aspergillus nidulans and Neurospora crassa Reveal Structural and Evolutionary Features of the Regulatory Networks. Front Microbiol 2018; 9:27. [PMID: 29403467 PMCID: PMC5780447 DOI: 10.3389/fmicb.2018.00027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Accepted: 01/08/2018] [Indexed: 12/21/2022] Open
Abstract
Transcriptional regulation has important roles in various biological processes (e.g., development and metabolism) in filamentous fungi. However, regulatory interactions between transcription factors (TFs) and their target genes in these species have only been described in different forms by primary scientific literature, which limits the integrated analysis of these data. Here, we extensively curated the reported transcriptional regulatory interactions in Aspergillus nidulans and Neurospora crassa. For each interaction, the identifiers of involved proteins or genes were unified, and the types of supporting experiments were recorded. Then, transcriptional regulatory networks were reconstructed from the interactions supported by classical low-throughput experiments. Analysis of the networks revealed the presence of hub targets regulated by multiple TFs and network motifs of other structures (e.g., regulatory loops). Comparison of the regulatory interactions between the two species identified 33 conserved interactions supported by classical experiments in both species, most of which are involved in the regulation of metabolic genes. We anticipate the curated data would serve as a catalog for the studies of transcriptional regulation in filamentous fungi.
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Affiliation(s)
- Yibo Hu
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China.,Hunan Provincial Key Laboratory of Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | - Yuqi Qin
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China.,National Glycoengineering Research Center, Shandong University, Jinan, China
| | - Guodong Liu
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China
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Takahashi H, Kusuya Y, Hagiwara D, Takahashi-Nakaguchi A, Sakai K, Gonoi T. Global gene expression reveals stress-responsive genes in Aspergillus fumigatus mycelia. BMC Genomics 2017; 18:942. [PMID: 29202712 PMCID: PMC5715996 DOI: 10.1186/s12864-017-4316-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 11/17/2017] [Indexed: 11/10/2022] Open
Abstract
Background Aspergillus fumigatus is a human fungal pathogen that causes aspergillosis in immunocompromised hosts. A. fumigatus is believed to be exposed to diverse environmental stresses in the host cells. The adaptation mechanisms are critical for infections in human bodies. Transcriptional networks in response to diverse environmental challenges remain to be elucidated. To gain insights into the adaptation to environmental stresses in A. fumigatus mycelia, we conducted time series transcriptome analyses. Results With the aid of RNA-seq, we explored the global gene expression profiles of mycelia in A. fumigatus upon exposure to diverse environmental changes, including heat, superoxide, and osmotic stresses. From the perspective of global transcriptomes, transient responses to superoxide and osmotic stresses were observed while responses to heat stresses were gradual. We identified the stress-responsive genes for particular stresses, and the 266 genes whose expression levels drastically fluctuated upon exposure to all tested stresses. Among these, the 77 environmental stress response genes are conserved in S. cerevisiae, suggesting that these genes might be more general prerequisites for adaptation to environmental stresses. Finally, we revealed the strong correlations among expression profiles of genes related to ‘rRNA processing’. Conclusions The time series transcriptome analysis revealed the stress-responsive genes underlying the adaptation mechanisms in A. fumigatus mycelia. These results will shed light on the regulatory networks underpinning the adaptation of the filamentous fungi. Electronic supplementary material The online version of this article (10.1186/s12864-017-4316-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hiroki Takahashi
- Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8673, Japan. .,Molecular Chirality Research Center, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan.
| | - Yoko Kusuya
- Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8673, Japan
| | - Daisuke Hagiwara
- Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8673, Japan
| | | | - Kanae Sakai
- Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8673, Japan
| | - Tohru Gonoi
- Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8673, Japan
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Hameed A, Hussain SA, Yang J, Ijaz MU, Liu Q, Suleria HAR, Song Y. Antioxidants Potential of the Filamentous Fungi (Mucor circinelloides). Nutrients 2017; 9:E1101. [PMID: 28991177 PMCID: PMC5691717 DOI: 10.3390/nu9101101] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 09/21/2017] [Accepted: 09/29/2017] [Indexed: 12/25/2022] Open
Abstract
Three important strains of Mucorcircinelloides grown in complete and minimal media for specified period (72 h, 120 h and 168 h) under submerged fermentation conditions were investigated for their potential antioxidants/secondary metabolite production. All mycelial extracts demonstrated effective antioxidant activities in terms of β-carotene/linoleic acid bleaching, radical scavenging, reduction of metal ions and chelating abilities against ferrous ions. Different extraction methods and solvent systems affected the recovery yield and antioxidant activities of the extracts significantly (p ≤ 0.05). Ethanolic extracts were found to be rich source of antioxidant components and subsequently more effective in antioxidant properties. Fermentation period and media used also significantly affected (p ≤ 0.05) the antioxidant production and the resulting antioxidant properties. The (ethanolic) extracts of all the strains from late exponential growth phase (120 h) showed highest antioxidant production with topmost reducing, chelating and radical scavenging capabilities. Strain MC277.49 was found to be the highest producer of antioxidants followed by MC108.16 and WJ11. Phenolic compounds were detected significantly in higher (p ≤ 0.05) amount succeeded by the condensed tannins and flavonoids. Total phenol content of each extract was attributed to overall antioxidant capacity. Submerged fermentation with nutritional stress conditions were found to be excellent way of producing surplus amount of natural antioxidants/secondary metabolites with their vast potential commercial application in food and pharmaceutical industries.
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Affiliation(s)
- Ahsan Hameed
- Colin Ratledge Center for Microbial Lipids, School of Agriculture Engineering and Food Science, Shandong University of Technology, Zibo 255049, China.
| | - Syed Ammar Hussain
- Colin Ratledge Center for Microbial Lipids, School of Agriculture Engineering and Food Science, Shandong University of Technology, Zibo 255049, China.
| | - Junhuan Yang
- Colin Ratledge Center for Microbial Lipids, School of Agriculture Engineering and Food Science, Shandong University of Technology, Zibo 255049, China.
| | - Muhammad Umair Ijaz
- Key Laboratory of Meat Processing & Quality Control, College of Food Sciences, Nanjing Agriculture University, Nanjing 210095, China.
| | - Qing Liu
- Colin Ratledge Center for Microbial Lipids, School of Agriculture Engineering and Food Science, Shandong University of Technology, Zibo 255049, China.
| | - Hafiz Ansar Rasul Suleria
- UQ School of Medicine, University of Queensland, Brisbane, QLD 4072, Australia.
- Department of Food, Nutrition, Dietetics & Health, Kansas State University, Manhattan, KS 66506, USA.
| | - Yuanda Song
- Colin Ratledge Center for Microbial Lipids, School of Agriculture Engineering and Food Science, Shandong University of Technology, Zibo 255049, China.
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Transcriptomic Analysis Reveals Genes Mediating Salt Tolerance through Calcineurin/CchA-Independent Signaling in Aspergillus nidulans. BIOMED RESEARCH INTERNATIONAL 2017; 2017:4378627. [PMID: 28904958 PMCID: PMC5585587 DOI: 10.1155/2017/4378627] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 06/01/2017] [Accepted: 07/10/2017] [Indexed: 01/11/2023]
Abstract
Adaptation to changes in the environment is crucial for the viability of all organisms. Although the importance of calcineurin in the stress response has been highlighted in filamentous fungi, little is known about the involvement of ion-responsive genes and pathways in conferring salt tolerance without calcium signaling. In this study, high-throughput RNA-seq was used to investigate salt stress-induced genes in the parent, ΔcnaB, and ΔcnaBΔcchA strains of Aspergillus nidulans, which differ greatly in salt adaption. In total, 2,884 differentially expressed genes including 1,382 up- and 1,502 downregulated genes were identified. Secondary transporters, which were upregulated to a greater extent in ΔcnaBΔcchA than in the parent or ΔcnaB strains, are likely to play important roles in response to salt stress. Furthermore, 36 genes were exclusively upregulated in the ΔcnaBΔcchA under salt stress. Functional analysis of differentially expressed genes revealed that genes involved in transport, heat shock protein binding, and cell division processes were exclusively activated in ΔcnaBΔcchA. Overall, our findings reveal that secondary transporters and stress-responsive genes may play crucial roles in salt tolerance to bypass the requirement for the CchA-calcineurin pathway, contributing to a deeper understanding of the mechanisms that influence fungal salt stress adaption in Aspergillus.
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Transcriptome-Based Modeling Reveals that Oxidative Stress Induces Modulation of the AtfA-Dependent Signaling Networks in Aspergillus nidulans. Int J Genomics 2017; 2017:6923849. [PMID: 28770220 PMCID: PMC5523550 DOI: 10.1155/2017/6923849] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 05/17/2017] [Accepted: 06/13/2017] [Indexed: 01/01/2023] Open
Abstract
To better understand the molecular functions of the master stress-response regulator AtfA in Aspergillus nidulans, transcriptomic analyses of the atfA null mutant and the appropriate control strains exposed to menadione sodium bisulfite- (MSB-), t-butylhydroperoxide- and diamide-induced oxidative stresses were performed. Several elements of oxidative stress response were differentially expressed. Many of them, including the downregulation of the mitotic cell cycle, as the MSB stress-specific upregulation of FeS cluster assembly and the MSB stress-specific downregulation of nitrate reduction, tricarboxylic acid cycle, and ER to Golgi vesicle-mediated transport, showed AtfA dependence. To elucidate the potential global regulatory role of AtfA governing expression of a high number of genes with very versatile biological functions, we devised a model based on the comprehensive transcriptomic data. Our model suggests that an important function of AtfA is to modulate the transduction of stress signals. Although it may regulate directly only a limited number of genes, these include elements of the signaling network, for example, members of the two-component signal transduction systems. AtfA acts in a stress-specific manner, which may increase further the number and diversity of AtfA-dependent genes. Our model sheds light on the versatility of the physiological functions of AtfA and its orthologs in fungi.
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Central Role of the Trehalose Biosynthesis Pathway in the Pathogenesis of Human Fungal Infections: Opportunities and Challenges for Therapeutic Development. Microbiol Mol Biol Rev 2017; 81:81/2/e00053-16. [PMID: 28298477 DOI: 10.1128/mmbr.00053-16] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Invasive fungal infections cause significant morbidity and mortality in part due to a limited antifungal drug arsenal. One therapeutic challenge faced by clinicians is the significant host toxicity associated with antifungal drugs. Another challenge is the fungistatic mechanism of action of some drugs. Consequently, the identification of fungus-specific drug targets essential for fitness in vivo remains a significant goal of medical mycology research. The trehalose biosynthetic pathway is found in a wide variety of organisms, including human-pathogenic fungi, but not in humans. Genes encoding proteins involved in trehalose biosynthesis are mechanistically linked to the metabolism, cell wall homeostasis, stress responses, and virulence of Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus. While there are a number of pathways for trehalose production across the tree of life, the TPS/TPP (trehalose-6-phosphate synthase/trehalose-6-phosphate phosphatase) pathway is the canonical pathway found in human-pathogenic fungi. Importantly, data suggest that proteins involved in trehalose biosynthesis play other critical roles in fungal metabolism and in vivo fitness that remain to be fully elucidated. By further defining the biology and functions of trehalose and its biosynthetic pathway components in pathogenic fungi, an opportunity exists to leverage this pathway as a potent antifungal drug target. The goal of this review is to cover the known roles of this important molecule and its associated biosynthesis-encoding genes in the human-pathogenic fungi studied to date and to employ these data to critically assess the opportunities and challenges facing development of this pathway as a therapeutic target.
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Detection of Transcriptionally Active Mycotoxin Gene Clusters: DNA Microarray. Methods Mol Biol 2016. [PMID: 27924550 DOI: 10.1007/978-1-4939-6707-0_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Various bioanalytical tools including DNA microarrays are frequently used to map global transcriptional changes in mycotoxin producer filamentous fungi. This effective hybridization-based transcriptomics technology helps researchers to identify genes of secondary metabolite gene clusters and record concomitant gene expression changes in these clusters initiated by versatile environmental conditions and/or gene deletions. Such transcriptional data are of great value when future mycotoxin control technologies are considered and elaborated. Giving the readers insights into RNA extraction and DNA microarray hybridization steps routinely used in our laboratories and also into the normalization and evaluation of primary gene expression data, we would like to contribute to the interlaboratory standardization of DNA microarray based transcriptomics studies being carried out in many laboratories worldwide in this important field of fungal biology.
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Leiter É, Bálint M, Miskei M, Orosz E, Szabó Z, Pócsi I. Stress tolerances of nullmutants of function-unknown genes encoding menadione stress-responsive proteins inAspergillus nidulans. J Basic Microbiol 2015; 56:827-33. [DOI: 10.1002/jobm.201500500] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 11/11/2015] [Indexed: 12/27/2022]
Affiliation(s)
- Éva Leiter
- Faculty of Science and Technology, Department of Biotechnology and Microbiology; University of Debrecen; Debrecen Hungary
| | - Mihály Bálint
- Faculty of Science and Technology, Department of Biotechnology and Microbiology; University of Debrecen; Debrecen Hungary
| | - Márton Miskei
- MTA-DE Momentum, Laboratory of Protein Dynamics, Department of Biochemistry and Molecular Biology; University of Debrecen; Debrecen Hungary
| | - Erzsébet Orosz
- Faculty of Science and Technology, Department of Biotechnology and Microbiology; University of Debrecen; Debrecen Hungary
| | - Zsuzsa Szabó
- Faculty of Science and Technology, Department of Biotechnology and Microbiology; University of Debrecen; Debrecen Hungary
| | - István Pócsi
- Faculty of Science and Technology, Department of Biotechnology and Microbiology; University of Debrecen; Debrecen Hungary
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Keller NP. Translating biosynthetic gene clusters into fungal armor and weaponry. Nat Chem Biol 2015; 11:671-7. [PMID: 26284674 DOI: 10.1038/nchembio.1897] [Citation(s) in RCA: 177] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 07/23/2015] [Indexed: 01/06/2023]
Abstract
Filamentous fungi are renowned for the production of a diverse array of secondary metabolites (SMs) where the genetic material required for synthesis of a SM is typically arrayed in a biosynthetic gene cluster (BGC). These natural products are valued for their bioactive properties stemming from their functions in fungal biology, key among those protection from abiotic and biotic stress and establishment of a secure niche. The producing fungus must not only avoid self-harm from endogenous SMs but also deliver specific SMs at the right time to the right tissue requiring biochemical aid. This review highlights functions of BGCs beyond the enzymatic assembly of SMs, considering the timing and location of SM production and other proteins in the clusters that control SM activity. Specifically, self-protection is provided by both BGC-encoded mechanisms and non-BGC subcellular containment of toxic SM precursors; delivery and timing is orchestrated through cellular trafficking patterns and stress- and developmental-responsive transcriptional programs.
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Affiliation(s)
- Nancy P Keller
- Department of Bacteriology and Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, Wisconsin, USA
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