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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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Tashiro M, Takazono T, Izumikawa K. Chronic pulmonary aspergillosis: comprehensive insights into epidemiology, treatment, and unresolved challenges. Ther Adv Infect Dis 2024; 11:20499361241253751. [PMID: 38899061 PMCID: PMC11186400 DOI: 10.1177/20499361241253751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Accepted: 04/23/2024] [Indexed: 06/21/2024] Open
Abstract
Chronic pulmonary aspergillosis (CPA) is a challenging respiratory infection caused by the environmental fungus Aspergillus. CPA has a poor prognosis, with reported 1-year mortality rates ranging from 7% to 32% and 5-year mortality rates ranging from 38% to 52%. A comprehensive understanding of the pathogen, pathophysiology, risk factors, diagnosis, surgery, hemoptysis treatment, pharmacological therapy, and prognosis is essential to manage CPA effectively. In particular, Aspergillus drug resistance and cryptic species pose significant challenges. CPA lacks tissue invasion and has specific features such as aspergilloma. The most critical risk factor for the development of CPA is pulmonary cavitation. Diagnostic approaches vary by CPA subtype, with computed tomography (CT) imaging and Aspergillus IgG antibodies being key. Treatment strategies include surgery, hemoptysis management, and antifungal therapy. Surgery is the curative option. However, reported postoperative mortality rates range from 0% to 5% and complications range from 11% to 63%. Simple aspergilloma generally has a low postoperative mortality rate, making surgery the first choice. Hemoptysis, observed in 50% of CPA patients, is a significant symptom and can be life-threatening. Bronchial artery embolization achieves hemostasis in 64% to 100% of cases, but 50% experience recurrent hemoptysis. The efficacy of antifungal therapy for CPA varies, with itraconazole reported to be 43-76%, voriconazole 32-80%, posaconazole 44-61%, isavuconazole 82.7%, echinocandins 42-77%, and liposomal amphotericin B 52-73%. Combinatorial treatments such as bronchoscopic triazole administration, inhalation, or direct injection of amphotericin B at the site of infection also show efficacy. A treatment duration of more than 6 months is recommended, with better efficacy reported for periods of more than 1 year. In anticipation of improvements in CPA management, ongoing advances in basic and clinical research are expected to contribute to the future of CPA management.
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Affiliation(s)
- Masato Tashiro
- Department of Infectious Diseases, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan
- Infection Control and Education Center, Nagasaki University Hospital, Nagasaki, Japan
| | - Takahiro Takazono
- Department of Infectious Diseases, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
- Department of Respiratory Medicine, Nagasaki University Hospital, Nagasaki, Japan
| | - Koichi Izumikawa
- Department of Infectious Diseases, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
- Infection Control and Education Center, Nagasaki University Hospital, Nagasaki, Japan
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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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Schruefer S, Pschibul A, Wong SSW, Sae-Ong T, Wolf T, Schäuble S, Panagiotou G, Brakhage AA, Aimanianda V, Kniemeyer O, Ebel F. Distinct transcriptional responses to fludioxonil in Aspergillus fumigatus and its ΔtcsC and Δskn7 mutants reveal a crucial role for Skn7 in the cell wall reorganizations triggered by this antifungal. BMC Genomics 2023; 24:684. [PMID: 37964194 PMCID: PMC10647056 DOI: 10.1186/s12864-023-09777-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 10/31/2023] [Indexed: 11/16/2023] Open
Abstract
BACKGROUND Aspergillus fumigatus is a major fungal pathogen that causes severe problems due to its increasing resistance to many therapeutic agents. Fludioxonil is a compound that triggers a lethal activation of the fungal-specific High Osmolarity Glycerol pathway. Its pronounced antifungal activity against A. fumigatus and other pathogenic molds renders this agent an attractive lead substance for the development of new therapeutics. The group III hydride histidine kinase TcsC and its downstream target Skn7 are key elements of the multistep phosphorelay that represents the initial section of the High Osmolarity Glycerol pathway. Loss of tcsC results in resistance to fludioxonil, whereas a Δskn7 mutant is partially, but not completely resistant. RESULTS In this study, we compared the fludioxonil-induced transcriptional responses in the ΔtcsC and Δskn7 mutant and their parental A. fumigatus strain. The number of differentially expressed genes correlates well with the susceptibility level of the individual strains. The wild type and, to a lesser extend also the Δskn7 mutant, showed a multi-faceted stress response involving genes linked to ribosomal and peroxisomal function, iron homeostasis and oxidative stress. A marked difference between the sensitive wild type and the largely resistant Δskn7 mutant was evident for many cell wall-related genes and in particular those involved in the biosynthesis of chitin. Biochemical data corroborate this differential gene expression that does not occur in response to hyperosmotic stress. CONCLUSIONS Our data reveal that fludioxonil induces a strong and TcsC-dependent stress that affects many aspects of the cellular machinery. The data also demonstrate a link between Skn7 and the cell wall reorganizations that foster the characteristic ballooning and the subsequent lysis of fludioxonil-treated cells.
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Affiliation(s)
- Sebastian Schruefer
- Institute for Infectious Diseases and Zoonoses, Ludwig-Maximilians-University, Munich, Germany
| | - Annica Pschibul
- Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
| | - Sarah Sze Wah Wong
- UMR2000, Molecular Mycology Unit, Mycology Department, Institut Pasteur, Université Paris Cité, CNRS, Paris, France
| | - Tongta Sae-Ong
- Microbiome Dynamics, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
| | - Thomas Wolf
- Microbiome Dynamics, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
| | - Sascha Schäuble
- Microbiome Dynamics, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
| | - Gianni Panagiotou
- Microbiome Dynamics, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
- Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Axel A Brakhage
- Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
- Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Vishukumar Aimanianda
- UMR2000, Molecular Mycology Unit, Mycology Department, Institut Pasteur, Université Paris Cité, CNRS, Paris, France
- Institut Pasteur, Université Paris Cité, Immunobiology of Aspergillus, Mycology Department, Paris, France
| | - Olaf Kniemeyer
- Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
| | - Frank Ebel
- Institute for Infectious Diseases and Zoonoses, Ludwig-Maximilians-University, Munich, Germany.
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Song X, Li T, Gu H, Yin H. Space exposure enhanced pectin-degrading enzymes expression and activity in Aspergillus costaricaensis. World J Microbiol Biotechnol 2023; 39:295. [PMID: 37658165 DOI: 10.1007/s11274-023-03740-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 08/24/2023] [Indexed: 09/03/2023]
Abstract
Aspergillus is a well-studied fungal genus that is widely used in the processing of plant biomass in industries. This study investigated the effects of space exposure on the ability of Aspergillus costaricaensis, a filamentous fungus isolated from rotten orange peel, to degrade pectin. These fungal spores were carried into space by the Long March 5B carrier rocket and exposed to cosmic radiation for 79 h. After the flight, these spores were resuscitated, and then the growing strains were screened with pectin as the sole carbon source, and the pectinase activity was evaluated. A mutant with increased biomass accumulation ability and pectin-degrading activity compared to the ground control strain was obtained. Comparative transcriptome analysis revealed that several CAZymes genes were significantly upregulated in the mutant, especially those related to pectin degradation. Among the 44 pectinases identified from the annotated genome, 42 were up-regulated. The activities of these pectinases are able to synergistically break down the structure of pectin. In addition, the expression of some genes involved in metabolism, sugar transport, and stress response was altered. These results imply that space exposure might serve as a potential mutagenesis breeding technique, offering the opportunity to acquire biomass-degrading microbial strains with potential for industrial application.
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Affiliation(s)
- Xiaohui Song
- Dalian Engineering Research Center for Carbohydrate Agricultural Preparations, Dalian Technology Innovation Center for Green Agriculture, Liaoning Provincial Key Laboratory of Carbohydrates, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
| | - Tang Li
- Dalian Engineering Research Center for Carbohydrate Agricultural Preparations, Dalian Technology Innovation Center for Green Agriculture, Liaoning Provincial Key Laboratory of Carbohydrates, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
| | - Hui Gu
- Dalian Engineering Research Center for Carbohydrate Agricultural Preparations, Dalian Technology Innovation Center for Green Agriculture, Liaoning Provincial Key Laboratory of Carbohydrates, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
| | - Heng Yin
- Dalian Engineering Research Center for Carbohydrate Agricultural Preparations, Dalian Technology Innovation Center for Green Agriculture, Liaoning Provincial Key Laboratory of Carbohydrates, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
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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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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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Luo X, Zhan X, Ruan R, Xi Y, Shen C, Wang H, Wang M. Genome-wide identification of the Penicillium digitatum bZIP gene family and the roles of one key member, PdatfA. Res Microbiol 2022; 173:103970. [PMID: 35868518 DOI: 10.1016/j.resmic.2022.103970] [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: 03/16/2022] [Revised: 07/03/2022] [Accepted: 07/08/2022] [Indexed: 11/16/2022]
Abstract
Penicillium digitatum is the most common cause of postharvest decay in citrus fruits around the world. Previous studies revealed that the bZIP gene family plays crucial roles in development, stress adaptation, and pathogenicity in fungi. However, little is known about the bZIP genes in P. digitatum. In this study, we systematically identified the bZIP family in 23 Penicillium species and analyzed their evolutionary relationships. We found that gene loss and gene duplication shaped the evolution of the Penicillium bZIP family. P. digitatum experienced 3 bZIP gene loss events, but with no gene duplication. We subsequently characterized the biological functions of one important member, PdatfA in P. digitatum by constructing the deletion mutant. Results showed that ΔPdatfA exhibited a moderate growth defect, reduced pigmentation, and slightly increased resistance to fungicides iprodione and fludioxonil. However, ΔPdatfA displayed similar rot symptoms to that of the wild type. The ΔPdatfA mycelia were not affected in response to oxidative stress while its conidia showed enhanced resistance due to the upregulation of catalases. Our results provide new insights into the evolution and functions of the bZIP gene family in Penicillium.
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Affiliation(s)
- Xiujun Luo
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Xiaori Zhan
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Ruoxin Ruan
- Hangzhou Academy of Agricultural Sciences, Hangzhou 310024, China
| | - Yue Xi
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Chenjia Shen
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Huizhong Wang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Mingshuang Wang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China.
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10
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Bitencourt TA, Hatanaka O, Pessoni AM, Freitas MS, Trentin G, Santos P, Rossi A, Martinez-Rossi NM, Alves LL, Casadevall A, Rodrigues ML, Almeida F. Fungal Extracellular Vesicles Are Involved in Intraspecies Intracellular Communication. mBio 2022; 13:e0327221. [PMID: 35012355 PMCID: PMC8749427 DOI: 10.1128/mbio.03272-21] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 11/08/2021] [Indexed: 12/16/2022] Open
Abstract
Fungal infections are associated with high mortality rates in humans. The risk of fungal diseases creates the urgent need to broaden the knowledge base regarding their pathophysiology. In this sense, the role of extracellular vesicles (EVs) has been described to convey biological information and participate in the fungus-host interaction process. We hypothesized that fungal EVs work as an additional element in the communication routes regulating fungal responses in intraspecies interaction systems. In this respect, the aim of this study was to address the gene regulation profiles prompted by fungal EVs in intraspecies recipient cells. Our data demonstrated the intraspecies uptake of EVs in pathogenic fungi, such as Candida albicans, Aspergillus fumigatus, and Paracoccidioides brasiliensis, and the effects triggered by EVs in fungal cells. In C. albicans, we evaluated the involvement of EVs in the yeast-to-hypha transition, while in P. brasiliensis and A. fumigatus the function of EVs as stress transducers was investigated. P. brasiliensis and A. fumigatus were exposed to an inhibitor of glycosylation or UV light, respectively. The results demonstrated the role of EVs in regulating the expression of target genes and triggering phenotypic changes. The EVs treatment induced cellular proliferation and boosted the yeast to hyphal transition in C. albicans, while they enhanced stress responsiveness in A. fumigatus and P. brasiliensis, establishing a role for EVs in fungal intraspecies communication. Thus, EVs regulate fungal behavior, acting as potent message effectors, and understanding their effects and mechanism(s) of action could be exploited in antifungal therapies. IMPORTANCE Here, we report a study about extracellular vesicles (EVs) as communication mediators in fungi. Our results demonstrated the role of EVs from Candida albicans, Aspergillus fumigatus, and Paracoccidioides brasiliensis regulating the expression of target genes and phenotypic features. We asked whether fungal EVs play a role as message effectors. We show that fungal EVs are involved in fungal interaction systems as potent message effectors, and understanding their effects and mechanisms of action could be exploited in antifungal therapies.
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Affiliation(s)
- Tamires A. Bitencourt
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, São Paulo, Brazil
| | - Otavio Hatanaka
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, São Paulo, Brazil
| | - Andre M. Pessoni
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, São Paulo, Brazil
| | - Mateus S. Freitas
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, São Paulo, Brazil
| | - Gabriel Trentin
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, São Paulo, Brazil
| | - Patrick Santos
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, São Paulo, Brazil
| | - Antonio Rossi
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Nilce M. Martinez-Rossi
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Lysangela L. Alves
- Gene Expression Regulation Laboratory, Carlos Chagas Institute, Fiocruz, Curitiba, PR, Brazil
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Marcio L. Rodrigues
- Gene Expression Regulation Laboratory, Carlos Chagas Institute, Fiocruz, Curitiba, PR, Brazil
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fausto Almeida
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, São Paulo, Brazil
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11
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Wang Y, Yang Z, Shi L, Yang R, Guo H, Zhang S, Geng G. Transcriptome analysis of Auricularia fibrillifera fruit-body responses to drought stress and rehydration. BMC Genomics 2022; 23:58. [PMID: 35033026 PMCID: PMC8760723 DOI: 10.1186/s12864-021-08284-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 12/28/2021] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Drought stress severely restricts edible fungus production. The genus Auricularia has a rare drought tolerance, a rehydration capability, and is nutrient rich. RESULTS The key genes and metabolic pathways involved in drought-stress and rehydration were investigated using a transcriptome analysis to clarify the relevant molecular mechanisms. In total, 173.93 Mb clean reads, 26.09 Gb of data bulk, and 52,954 unigenes were obtained. Under drought-stress and rehydration conditions, 14,235 and 8539 differentially expressed genes, respectively, were detected. 'Tyrosine metabolic', 'caffeine metabolism', 'ribosome', 'phagosome', and 'proline and arginine metabolism', as well as 'peroxisome' and 'mitogen-activated protein kinase signaling' pathways, had major roles in A. fibrillifera responses to drought stress. 'Tyrosine' and 'caffeine metabolism' might reveal unknown mechanisms for the antioxidation of A. fibrillifera under drought-stress conditions. During the rehydration process, 'diterpenoid biosynthesis', 'butanoate metabolism', 'C5-branched dibasic acid', and 'aflatoxin biosynthesis' pathways were significantly enriched. Gibberellins and γ-aminobutyric acid were important in the recovery of A. fibrillifera growth after rehydration. Many genes related to antibiotics, vitamins, and other health-related ingredients were found in A. fibrillifera. CONCLUSION These findings suggested that the candidate genes and metabolites involved in crucial biological pathways might regulate the drought tolerance or rehydration of Auricularia, shedding light on the corresponding mechanisms and providing new potential targets for the breeding and cultivation of drought-tolerant fungi.
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Affiliation(s)
- Yiqin Wang
- College of Agriculture, Guizhou University, Guiyang, Guizhou, China
| | - Zhifen Yang
- College of Agriculture, Guizhou University, Guiyang, Guizhou, China
| | - Luxi Shi
- College of Agriculture, Guizhou University, Guiyang, Guizhou, China
| | - Rui Yang
- College of Agriculture, Guizhou University, Guiyang, Guizhou, China
| | - Hao Guo
- College of Agriculture, Guizhou University, Guiyang, Guizhou, China
| | - Suqin Zhang
- College of Agriculture, Guizhou University, Guiyang, Guizhou, China.
| | - Guangdong Geng
- College of Agriculture, Guizhou University, Guiyang, Guizhou, China.
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12
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Yaakoub H, Sanchez NS, Ongay-Larios L, Courdavault V, Calenda A, Bouchara JP, Coria R, Papon N. The high osmolarity glycerol (HOG) pathway in fungi †. Crit Rev Microbiol 2021; 48:657-695. [PMID: 34893006 DOI: 10.1080/1040841x.2021.2011834] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
While fungi are widely occupying nature, many species are responsible for devastating mycosis in humans. Such niche diversity explains how quick fungal adaptation is necessary to endow the capacity of withstanding fluctuating environments and to cope with host-imposed conditions. Among all the molecular mechanisms evolved by fungi, the most studied one is the activation of the phosphorelay signalling pathways, of which the high osmolarity glycerol (HOG) pathway constitutes one of the key molecular apparatus underpinning fungal adaptation and virulence. In this review, we summarize the seminal knowledge of the HOG pathway with its more recent developments. We specifically described the HOG-mediated stress adaptation, with a particular focus on osmotic and oxidative stress, and point out some lags in our understanding of its involvement in the virulence of pathogenic species including, the medically important fungi Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus, compared to the model yeast Saccharomyces cerevisiae. Finally, we also highlighted some possible applications of the HOG pathway modifications to improve the fungal-based production of natural products in the industry.
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Affiliation(s)
- Hajar Yaakoub
- Univ Angers, Univ Brest, GEIHP, SFR ICAT, Angers, France
| | - Norma Silvia Sanchez
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico
| | - Laura Ongay-Larios
- Unidad de Biología Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Vincent Courdavault
- EA2106 "Biomolécules et Biotechnologies Végétales", Université de Tours, Tours, France
| | | | | | - Roberto Coria
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico
| | - Nicolas Papon
- Univ Angers, Univ Brest, GEIHP, SFR ICAT, Angers, France
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13
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Ross BS, Lofgren LA, Ashare A, Stajich JE, Cramer RA. Aspergillus fumigatus In-Host HOG Pathway Mutation for Cystic Fibrosis Lung Microenvironment Persistence. mBio 2021; 12:e0215321. [PMID: 34465017 PMCID: PMC8406193 DOI: 10.1128/mbio.02153-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 07/26/2021] [Indexed: 11/24/2022] Open
Abstract
The prevalence of Aspergillus fumigatus colonization in individuals with cystic fibrosis (CF) and subsequent fungal persistence in the lung is increasingly recognized. However, there is no consensus for clinical management of A. fumigatus in CF individuals, due largely to uncertainty surrounding A. fumigatus CF pathogenesis and virulence mechanisms. To address this gap in knowledge, a longitudinal series of A. fumigatus isolates from an individual with CF were collected over 4.5 years. Isolate genotypes were defined with whole-genome sequencing that revealed both transitory and persistent A. fumigatus in the lung. Persistent lineage isolates grew most readily in a low-oxygen culture environment, and conidia were more sensitive to oxidative stress-inducing conditions than those from nonpersistent isolates. Closely related persistent isolates harbored a unique allele of the high-osmolarity glycerol (HOG) pathway mitogen-activated protein kinase kinase, Pbs2 (pbs2C2). Data suggest this novel pbs2C2 allele arose in vivo and is necessary for the fungal response to osmotic stress in a low-oxygen environment through hyperactivation of the HOG (SakA) signaling pathway. Hyperactivation of the HOG pathway through pbs2C2 comes at the cost of decreased conidial stress resistance in the presence of atmospheric oxygen levels. These novel findings shed light on pathoadaptive mechanisms of A. fumigatus in CF, lay the foundation for identifying persistent A. fumigatus isolates that may require antifungal therapy, and highlight considerations for successful culture of persistent Aspergillus CF isolates. IMPORTANCE Aspergillus fumigatus infection causes a spectrum of clinical manifestations. For individuals with cystic fibrosis (CF), allergic bronchopulmonary aspergillosis (ABPA) is an established complication, but there is a growing appreciation for A. fumigatus airway persistence in CF disease progression. There currently is little consensus for clinical management of A. fumigatus long-term culture positivity in CF. A better understanding of A. fumigatus pathogenesis mechanisms in CF is expected to yield insights into when antifungal therapies are warranted. Here, a 4.5-year longitudinal collection of A. fumigatus isolates from a patient with CF identified a persistent lineage that harbors a unique allele of the Pbs2 mitogen-activated protein kinase kinase (MAPKK) necessary for unique CF-relevant stress phenotypes. Importantly for A. fumigatus CF patient diagnostics, this allele provides increased fitness under CF lung-like conditions at a cost of reduced in vitro growth under standard laboratory conditions. These data illustrate a molecular mechanism for A. fumigatus CF lung persistence with implications for diagnostics and antifungal therapy.
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Affiliation(s)
- Brandon S. Ross
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Lotus A. Lofgren
- Department of Microbiology and Plant Pathology, Institute for Integrative Genome Biology, University of California Riverside, Riverside, California, USA
| | - Alix Ashare
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
- Department of Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Jason E. Stajich
- Department of Microbiology and Plant Pathology, Institute for Integrative Genome Biology, University of California Riverside, Riverside, California, USA
| | - Robert A. Cramer
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
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14
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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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15
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Abstract
Aspergillus fumigatus is a major opportunistic fungal pathogen of immunocompromised and immunocompetent hosts. To successfully establish an infection, A. fumigatus needs to use host carbon sources, such as acetate, present in the body fluids and peripheral tissues. However, utilization of acetate as a carbon source by fungi in the context of infection has not been investigated. This work shows that acetate is metabolized via different pathways in A. fumigatus and that acetate utilization is under the regulatory control of a transcription factor (TF), FacB. A. fumigatus acetate utilization is subject to carbon catabolite repression (CCR), although this is only partially dependent on the TF and main regulator of CCR CreA. The available extracellular carbon source, in this case glucose and acetate, significantly affected A. fumigatus virulence traits such as secondary metabolite secretion and cell wall composition, with the latter having consequences for resistance to oxidative stress, antifungal drugs, and human neutrophil-mediated killing. Furthermore, deletion of facB significantly impaired the in vivo virulence of A. fumigatus in both insect and mammalian models of invasive aspergillosis. This is the first report on acetate utilization in A. fumigatus, and this work further highlights the importance of available host-specific carbon sources in shaping fungal virulence traits and subsequent disease outcome, and a potential target for the development of antifungal strategies. IMPORTANCE Aspergillus fumigatus is an opportunistic fungal pathogen in humans. During infection, A. fumigatus is predicted to use host carbon sources, such as acetate, present in body fluids and peripheral tissues, to sustain growth and promote colonization and invasion. This work shows that A. fumigatus metabolizes acetate via different pathways, a process that is dependent on the transcription factor FacB. Furthermore, the type and concentration of the extracellular available carbon source were determined to shape A. fumigatus virulence determinants such as secondary metabolite secretion and cell wall composition. Subsequently, interactions with immune cells are altered in a carbon source-specific manner. FacB is required for A. fumigatus in vivo virulence in both insect and mammalian models of invasive aspergillosis. This is the first report that characterizes acetate utilization in A. fumigatus and highlights the importance of available host-specific carbon sources in shaping virulence traits and potentially subsequent disease outcome.
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16
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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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17
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Durieux MF, Melloul É, Jemel S, Roisin L, Dardé ML, Guillot J, Dannaoui É, Botterel F. Galleria mellonella as a screening tool to study virulence factors of Aspergillus fumigatus. Virulence 2021; 12:818-834. [PMID: 33682618 PMCID: PMC7946008 DOI: 10.1080/21505594.2021.1893945] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
The invertebrate Galleria mellonella has increasingly and widely been used in the last few years to study complex host–microbe interactions. Aspergillus fumigatus is one of the most pathogenic fungi causing life-threatening diseases in humans and animals. Galleria mellonella larvae has been proven as a reliable model for the analysis of pathogenesis and virulence factors, enable to screen a large number of A. fumigatus strains. This review describes the different uses of G. mellonella to study A. fumigatus and provides a comparison of the different protocols to trace fungal pathogenicity. The review also includes a summary of the diverse mutants tested in G. mellonella, and their respective contribution to A. fumigatus virulence. Previous investigations indicated that G. mellonella should be considered as an interesting tool even though a mammalian model may be required to complete and verify initial data.
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Affiliation(s)
- Marie-Fleur Durieux
- Laboratoire de Parasitologie - Mycologie, CHU de Limoges, Limoges, France.,EA 7380 Dynamic, Université Paris Est Créteil, EnvA, USC ANSES, Créteil, France
| | - Élise Melloul
- EA 7380 Dynamic, Université Paris Est Créteil, EnvA, USC ANSES, Créteil, France
| | - Sana Jemel
- EA 7380 Dynamic, Université Paris Est Créteil, EnvA, USC ANSES, Créteil, France
| | - Lolita Roisin
- EA 7380 Dynamic, Université Paris Est Créteil, EnvA, USC ANSES, Créteil, France
| | - Marie-Laure Dardé
- Laboratoire de Parasitologie - Mycologie, CHU de Limoges, Limoges, France
| | - Jacques Guillot
- EA 7380 Dynamic, Université Paris Est Créteil, EnvA, USC ANSES, Créteil, France.,École Nationale Vétérinaire d'Alfort, Maisons-Alfort, France
| | - Éric Dannaoui
- EA 7380 Dynamic, Université Paris Est Créteil, EnvA, USC ANSES, Créteil, France.,Unité de Parasitologie-mycologie, Service de Microbiologie, Université Paris Descartes, Hôpital Européen Georges Pompidou, AP-HP, Paris, France
| | - Françoise Botterel
- EA 7380 Dynamic, Université Paris Est Créteil, EnvA, USC ANSES, Créteil, France.,Unité de Mycologie, Département de Prévention, Diagnostic Et Traitement Des Infections, Groupe Hospitalier Henri Mondor - Albert Chenevier, APHP, France
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18
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Silva LP, Horta MAC, Goldman GH. Genetic Interactions Between Aspergillus fumigatus Basic Leucine Zipper (bZIP) Transcription Factors AtfA, AtfB, AtfC, and AtfD. FRONTIERS IN FUNGAL BIOLOGY 2021; 2:632048. [PMID: 37744135 PMCID: PMC10512269 DOI: 10.3389/ffunb.2021.632048] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Accepted: 01/08/2021] [Indexed: 09/26/2023]
Abstract
Aspergillus fumigatus is an opportunistic fungus, capable of causing Invasive Aspergillosis in immunocompromised patients, recently transplanted or undergoing chemotherapy. In the present work, we continued the investigation on A. fumigatus AtfA-D transcription factors (TFs) characterizing possible genetic and physical interactions between them after normal growth and stressing conditions. We constructed double null mutants for all the possible combinations of ΔatfA-, -B, -C, and -D, and look into their susceptibility to different stressing conditions. Our results indicate complex genetic interactions among these TFs that could impact the response to different kinds of stressful conditions. AtfA-D interactions also affect the A. fumigatus virulence in Galleria mellonella. AtfA:GFP is ~97% located in the nucleus while about 20-30% of AtfB, -C, and -D:GFP locate into the nucleus in the absence of any stress. Under stressing conditions, AtfB, -C, and -D:GFP translocate to the nucleus about 60-80% upon the addition of sorbitol or H2O2. These four TFs are also interacting physically forming all the possible combinations of heterodimers. We also identified that AtfA-D physically interact with the MAPK SakA in the absence of any stress and upon osmotic and cell wall stresses. They are involved in the accumulation of trehalose, glycogen and metabolic assimilation of different carbon sources.
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Affiliation(s)
| | | | - Gustavo Henrique Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
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19
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Carrillo AJ, Cabrera IE, Spasojevic MJ, Schacht P, Stajich JE, Borkovich KA. Clustering analysis of large-scale phenotypic data in the model filamentous fungus Neurospora crassa. BMC Genomics 2020; 21:755. [PMID: 33138786 PMCID: PMC7607824 DOI: 10.1186/s12864-020-07131-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 10/09/2020] [Indexed: 11/28/2022] Open
Abstract
Background With 9730 protein-coding genes and a nearly complete gene knockout strain collection, Neurospora crassa is a major model organism for filamentous fungi. Despite this abundance of information, the phenotypes of these gene knockout mutants have not been categorized to determine whether there are broad correlations between phenotype and any genetic features. Results Here, we analyze data for 10 different growth or developmental phenotypes that have been obtained for 1168 N. crassa knockout mutants. Of these mutants, 265 (23%) are in the normal range, while 903 (77%) possess at least one mutant phenotype. With the exception of unclassified functions, the distribution of functional categories for genes in the mutant dataset mirrors that of the N. crassa genome. In contrast, most genes do not possess a yeast ortholog, suggesting that our analysis will reveal functions that are not conserved in Saccharomyces cerevisiae. To leverage the phenotypic data to identify pathways, we used weighted Partitioning Around Medoids (PAM) approach with 40 clusters. We found that genes encoding metabolic, transmembrane and protein phosphorylation-related genes are concentrated in subsets of clusters. Results from K-Means clustering of transcriptomic datasets showed that most phenotypic clusters contain multiple expression profiles, suggesting that co-expression is not generally observed for genes with shared phenotypes. Analysis of yeast orthologs of genes that co-clustered in MAPK signaling cascades revealed potential networks of interacting proteins in N. crassa. Conclusions Our results demonstrate that clustering analysis of phenotypes is a promising tool for generating new hypotheses regarding involvement of genes in cellular pathways in N. crassa. Furthermore, information about gene clusters identified in N. crassa should be applicable to other filamentous fungi, including saprobes and pathogens.
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Affiliation(s)
- Alexander J Carrillo
- Department of Microbiology and Plant Pathology, University of California, 900 University Avenue, Riverside, CA, 92521, USA
| | - Ilva E Cabrera
- Department of Microbiology and Plant Pathology, University of California, 900 University Avenue, Riverside, CA, 92521, USA
| | - Marko J Spasojevic
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, California, 92521, USA
| | - Patrick Schacht
- Department of Microbiology and Plant Pathology, University of California, 900 University Avenue, Riverside, CA, 92521, USA
| | - Jason E Stajich
- Department of Microbiology and Plant Pathology, University of California, 900 University Avenue, Riverside, CA, 92521, USA
| | - Katherine A Borkovich
- Department of Microbiology and Plant Pathology, University of California, 900 University Avenue, Riverside, CA, 92521, USA.
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de Assis LJ, Silva LP, Liu L, Schmitt K, Valerius O, Braus GH, Ries LNA, Goldman GH. The High Osmolarity Glycerol Mitogen-Activated Protein Kinase regulates glucose catabolite repression in filamentous fungi. PLoS Genet 2020; 16:e1008996. [PMID: 32841242 PMCID: PMC7473523 DOI: 10.1371/journal.pgen.1008996] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 09/04/2020] [Accepted: 07/15/2020] [Indexed: 12/22/2022] Open
Abstract
The utilization of different carbon sources in filamentous fungi underlies a complex regulatory network governed by signaling events of different protein kinase pathways, including the high osmolarity glycerol (HOG) and protein kinase A (PKA) pathways. This work unraveled cross-talk events between these pathways in governing the utilization of preferred (glucose) and non-preferred (xylan, xylose) carbon sources in the reference fungus Aspergillus nidulans. An initial screening of a library of 103 non-essential protein kinase (NPK) deletion strains identified several mitogen-activated protein kinases (MAPKs) to be important for carbon catabolite repression (CCR). We selected the MAPKs Ste7, MpkB, and PbsA for further characterization and show that they are pivotal for HOG pathway activation, PKA activity, CCR via regulation of CreA cellular localization and protein accumulation, as well as for hydrolytic enzyme secretion. Protein-protein interaction studies show that Ste7, MpkB, and PbsA are part of the same protein complex that regulates CreA cellular localization in the presence of xylan and that this complex dissociates upon the addition of glucose, thus allowing CCR to proceed. Glycogen synthase kinase (GSK) A was also identified as part of this protein complex and shown to potentially phosphorylate two serine residues of the HOG MAPKK PbsA. This work shows that carbon source utilization is subject to cross-talk regulation by protein kinases of different signaling pathways. Furthermore, this study provides a model where the correct integration of PKA, HOG, and GSK signaling events are required for the utilization of different carbon sources. Filamentous fungi secrete an array of biotechnologically valuable enzymes, with enzyme production being inhibited in the presence of preferred carbon sources, such as glucose, in a process known as carbon catabolite repression (CCR). This work unravels upstream signalling events that regulate CCR in Aspergillus nidulans. Different mitogen-activated protein kinases (MAPKs) were identified and shown to be crucial for CCR and protein kinase A (PKA) activity, which is essential for carbon source utilisation in filamentous fungi. Furthermore, the MAPKs formed a protein complex with additional protein kinases, such as glycogen synthase kinase (GSK), which is important for glucose metabolism; resulting in the inhibition of CCR in the presence of non-preferred carbon sources. GSK was shown to potentially phosphorylate the MAPK PbsA of the high osmolarity glycerol (HOG) pathway. This study thus unravels the cross-talk between protein kinases from different signalling pathways that regulate carbon source utilisation in filamentous fungi.
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Affiliation(s)
- Leandro José de Assis
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Bloco Q, Universidade de São Paulo, Brazil
| | - Lilian Pereira Silva
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Bloco Q, Universidade de São Paulo, Brazil
| | - Li Liu
- Department of Molecular Microbiology and Genetics and Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Goettingen, Germany
| | - Kerstin Schmitt
- Department of Molecular Microbiology and Genetics and Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Goettingen, Germany
| | - Oliver Valerius
- Department of Molecular Microbiology and Genetics and Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Goettingen, Germany
| | - Gerhard H. Braus
- Department of Molecular Microbiology and Genetics and Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Goettingen, Germany
- * E-mail: (GHB); (LNAR); (GHG)
| | - Laure Nicolas Annick Ries
- Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Brazil
- * E-mail: (GHB); (LNAR); (GHG)
| | - Gustavo Henrique Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Bloco Q, Universidade de São Paulo, Brazil
- Institute for Advanced Study, Technical University of Munich, Garching, Germany
- * E-mail: (GHB); (LNAR); (GHG)
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21
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Ries LNA, Pardeshi L, Dong Z, Tan K, Steenwyk JL, Colabardini AC, Ferreira Filho JA, de Castro PA, Silva LP, Preite NW, Almeida F, de Assis LJ, dos Santos RAC, Bowyer P, Bromley M, Owens RA, Doyle S, Demasi M, Hernández DCR, Netto LES, Pupo MT, Rokas A, Loures FV, Wong KH, Goldman GH. The Aspergillus fumigatus transcription factor RglT is important for gliotoxin biosynthesis and self-protection, and virulence. PLoS Pathog 2020; 16:e1008645. [PMID: 32667960 PMCID: PMC7384679 DOI: 10.1371/journal.ppat.1008645] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 07/27/2020] [Accepted: 05/19/2020] [Indexed: 12/21/2022] Open
Abstract
Aspergillus fumigatus is an opportunistic fungal pathogen that secretes an array of immune-modulatory molecules, including secondary metabolites (SMs), which contribute to enhancing fungal fitness and growth within the mammalian host. Gliotoxin (GT) is a SM that interferes with the function and recruitment of innate immune cells, which are essential for eliminating A. fumigatus during invasive infections. We identified a C6 Zn cluster-type transcription factor (TF), subsequently named RglT, important for A. fumigatus oxidative stress resistance, GT biosynthesis and self-protection. RglT regulates the expression of several gli genes of the GT biosynthetic gene cluster, including the oxidoreductase-encoding gene gliT, by directly binding to their respective promoter regions. Subsequently, RglT was shown to be important for virulence in a chemotherapeutic murine model of invasive pulmonary aspergillosis (IPA). Homologues of RglT and GliT are present in eurotiomycete and sordariomycete fungi, including the non-GT-producing fungus A. nidulans, where a conservation of function was described. Phylogenetically informed model testing led to an evolutionary scenario in which the GliT-based resistance mechanism is ancestral and RglT-mediated regulation of GliT occurred subsequently. In conclusion, this work describes the function of a previously uncharacterised TF in oxidative stress resistance, GT biosynthesis and self-protection in both GT-producing and non-producing Aspergillus species.
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Affiliation(s)
- Laure N. A. Ries
- Faculty of Medicine of Ribeirao Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Lakhansing Pardeshi
- Genomics and Bioinformatics Core, Faculty of Health Sciences, University of Macau, Macau SAR, China
- Faculty of Health Sciences, University of Macau, Macau SAR, China
| | - Zhiqiang Dong
- Faculty of Health Sciences, University of Macau, Macau SAR, China
| | - Kaeling Tan
- Genomics and Bioinformatics Core, Faculty of Health Sciences, University of Macau, Macau SAR, China
- Faculty of Health Sciences, University of Macau, Macau SAR, China
- Centre for Precision Medicine and Research and Training, University of Macau, Macau SAR, China
| | - Jacob L. Steenwyk
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States of America
| | - Ana Cristina Colabardini
- Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Jaire A. Ferreira Filho
- Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Patricia A. de Castro
- Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Lilian P. Silva
- Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Nycolas W. Preite
- Institute of Science and Technology, Federal University of São Paulo, São José dos Campos, Brazil
| | - Fausto Almeida
- Faculty of Medicine of Ribeirao Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Leandro J. de Assis
- Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Renato A. C. dos Santos
- Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Paul Bowyer
- Manchester Fungal Infection Group, Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Michael Bromley
- Manchester Fungal Infection Group, Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | | | - Sean Doyle
- Department of Biology, Maynooth University, Maynooth, Ireland
| | - Marilene Demasi
- Institute Butantan, Laboratory of Biochemistry and Biophysics, São Paulo, Brazil
| | - Diego C. R. Hernández
- Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, Ribeirão Preto, Brazil
| | | | - Monica T. Pupo
- Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States of America
| | - Flavio V. Loures
- Institute of Science and Technology, Federal University of São Paulo, São José dos Campos, Brazil
| | - Koon H. Wong
- Genomics and Bioinformatics Core, Faculty of Health Sciences, University of Macau, Macau SAR, China
- Institute of Translational Medicine, University of Macau, Macau SAR, China
| | - Gustavo H. Goldman
- Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, Ribeirão Preto, Brazil
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22
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Abstract
Aspergillus fumigatus, one of the most important human-pathogenic fungal species, is able to cause aspergillosis, a heterogeneous group of diseases that presents a wide range of clinical manifestations. Invasive pulmonary aspergillosis is the most serious pathology in terms of patient outcome and treatment, with a high mortality rate ranging from 50% to 95% primarily affecting immunocompromised patients. Azoles have been used for many years as the main antifungal agents to treat and prevent invasive aspergillosis. However, there were several reports of evolution of clinical azole resistance in the last decade. Caspofungin, a noncompetitive β-1,3-glucan synthase inhibitor, has been used against A. fumigatus, but it is fungistatic and is recommended as second-line therapy for invasive aspergillosis. More information about caspofungin tolerance and resistance is necessary in order to refine antifungal strategies that target the fungal cell wall. Here, we screened a transcription factor (TF) deletion library for TFs that can mediate caspofungin tolerance and resistance. We have identified 11 TFs that are important for caspofungin sensitivity and/or for the caspofungin paradoxical effect (CPE). These TFs encode proteins involved in the basal modulation of the RNA polymerase II initiation sites, calcium metabolism or cell wall remodeling, and mitochondrial respiratory function. The study of those genes regulated by TFs identified in this work will provide a better understanding of the signaling pathways that are important for caspofungin tolerance and resistance. Aspergillus fumigatus is the leading cause of pulmonary fungal diseases. Azoles have been used for many years as the main antifungal agents to treat and prevent invasive aspergillosis. However, in the last 10 years there have been several reports of azole resistance in A. fumigatus and new strategies are needed to combat invasive aspergillosis. Caspofungin is effective against other human-pathogenic fungal species, but it is fungistatic only against A. fumigatus. Resistance to caspofungin in A. fumigatus has been linked to mutations in the fksA gene that encodes the target enzyme of the drug β-1,3-glucan synthase. However, tolerance of high caspofungin concentrations, a phenomenon known as the caspofungin paradoxical effect (CPE), is also important for subsequent adaptation and drug resistance evolution. Here, we identified and characterized the transcription factors involved in the response to CPE by screening an A. fumigatus library of 484 null transcription factors (TFs) in CPE drug concentrations. We identified 11 TFs that had reduced CPE and that encoded proteins involved in the basal modulation of the RNA polymerase II initiation sites, calcium metabolism, and cell wall remodeling. One of these TFs, FhdA, was important for mitochondrial respiratory function and iron metabolism. The ΔfhdA mutant showed decreased growth when exposed to Congo red or to high temperature. Transcriptome sequencing (RNA-seq) analysis and further experimental validation indicated that the ΔfhdA mutant showed diminished respiratory capacity, probably affecting several pathways related to the caspofungin tolerance and resistance. Our results provide the foundation to understand signaling pathways that are important for caspofungin tolerance and resistance.
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Abstract
Aspergillus fumigatus is an opportunistic and allergenic pathogenic fungus, responsible for fungal infections in humans. A. fumigatus infections are usually treated with polyenes, azoles, or echinocandins. Echinocandins, such as caspofungin, can inhibit the biosynthesis of the β-1,3-glucan polysaccharide, affecting the integrity of the cell wall and leading to fungal death. In some A. fumigatus strains, caspofungin treatment at high concentrations induces an increase of fungal growth, a phenomenon called the caspofungin paradoxical effect (CPE). Here, we analyze the proteome and phosphoproteome of the A. fumigatus wild-type strain and of mitogen-activated protein kinase (MAPK) mpkA and sakA null mutant strains during CPE (2 μg/ml caspofungin for 1 h). The wild-type proteome showed 75 proteins and 814 phosphopeptides (corresponding to 520 proteins) altered in abundance in response to caspofungin treatment. The ΔmpkA (ΔmpkA caspofungin/wild-type caspofungin) and ΔsakA (ΔsakA caspofungin/wild-type caspofungin) strains displayed 626 proteins and 1,236 phosphopeptides (corresponding to 703 proteins) and 101 proteins and 1,217 phosphopeptides (corresponding to 645 proteins), respectively, altered in abundance. Functional characterization of the phosphopeptides from the wild-type strain exposed to caspofungin showed enrichment for transcription factors, protein kinases, and cytoskeleton proteins. Proteomic analysis of the ΔmpkA and ΔsakA mutants indicated that control of proteins involved in metabolism, such as in production of secondary metabolites, was highly represented in both mutants. Results of functional categorization of phosphopeptides from both mutants were very similar and showed a high number of proteins with decreased phosphorylation of proteins involved in transcriptional control, DNA/RNA binding, cell cycle control, and DNA processing. This report reveals novel transcription factors involved in caspofungin tolerance.IMPORTANCE Aspergillus fumigatus is an opportunistic human-pathogenic fungus causing allergic reactions or systemic infections, such as invasive pulmonary aspergillosis in immunocompromised patients. Caspofungin is an echinocandin that impacts the construction of the fungal cell wall by inhibiting the biosynthesis of the β-1,3-glucan polysaccharide. Caspofungin is a fungistatic drug and is recommended as a second-line therapy for treatment of aspergillosis. Treatment at high concentrations induces an increase of fungal growth, a phenomenon called the caspofungin paradoxical effect (CPE). Collaboration between the mitogen-activated protein kinases (MAPK) of the cell wall integrity (MapkA) and high-osmolarity glycerol (SakA) pathways is essential for CPE. Here, we investigate the global proteome and phosphoproteome of A. fumigatus wild-type, ΔmpkA, and ΔsakA strains upon CPE. This study showed intense cross talk between the two MAPKs for the CPE and identified novel protein kinases and transcription factors possibly important for CPE. Increased understanding of how the modulation of protein phosphorylation may affect the fungal growth in the presence of caspofungin represents an important step in the development of new strategies and methods to combat the fungus inside the host.
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Pang KL, Chiang MWL, Guo SY, Shih CY, Dahms HU, Hwang JS, Cha HJ. Growth study under combined effects of temperature, pH and salinity and transcriptome analysis revealed adaptations of Aspergillus terreus NTOU4989 to the extreme conditions at Kueishan Island Hydrothermal Vent Field, Taiwan. PLoS One 2020; 15:e0233621. [PMID: 32453769 PMCID: PMC7250430 DOI: 10.1371/journal.pone.0233621] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 05/08/2020] [Indexed: 12/03/2022] Open
Abstract
A high diversity of fungi was discovered on various substrates collected at the marine shallow-water Kueishan Island Hydrothermal Vent Field, Taiwan, using culture and metabarcoding methods but whether these fungi can grow and play an active role in such an extreme environment is unknown. We investigated the combined effects of different salinity, temperature and pH on growth of ten fungi (in the genera Aspergillus, Penicillium, Fodinomyces, Microascus, Trichoderma, Verticillium) isolated from the sediment and the vent crab Xenograpsus testudinatus. The growth responses of the tested fungi could be referred to three groups: (1) wide pH, salinity and temperature ranges, (2) salinity-dependent and temperature-sensitive, and (3) temperature-tolerant. Aspergillus terreus NTOU4989 was the only fungus which showed growth at 45 °C, pH 3 and 30 ‰ salinity, and might be active near the vents. We also carried out a transcriptome analysis to understand the molecular adaptations of A. terreus NTOU4989 under these extreme conditions. Data revealed that stress-related genes were differentially expressed at high temperature (45 °C); for instance, mannitol biosynthetic genes were up-regulated while glutathione S-transferase and amino acid oxidase genes down-regulated in response to high temperature. On the other hand, hydrogen ion transmembrane transport genes and phenylalanine ammonia lyase were up-regulated while pH-response transcription factor was down-regulated at pH 3, a relative acidic environment. However, genes related to salt tolerance, such as glycerol lipid metabolism and mitogen-activated protein kinase, were up-regulated in both conditions, possibly related to maintaining water homeostasis. The results of this study revealed the genetic evidence of adaptation in A. terreus NTOU4989 to changes of environmental conditions.
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Affiliation(s)
- Ka-Lai Pang
- Institute of Marine Biology and Centre of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan
| | | | - Sheng-Yu Guo
- Institute of Marine Biology and Centre of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan
| | - Chi-Yu Shih
- Institute of Marine Biology and Centre of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan
| | - Hans U Dahms
- Department of Biomedical Science and Environment Biology, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Jiang-Shiou Hwang
- Institute of Marine Biology and Centre of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan
| | - Hyo-Jung Cha
- Institute of Marine Biology and Centre of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan
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25
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Sturm L, Geißel B, Martin R, Wagener J. Differentially Regulated Transcription Factors and ABC Transporters in a Mitochondrial Dynamics Mutant Can Alter Azole Susceptibility of Aspergillus fumigatus. Front Microbiol 2020; 11:1017. [PMID: 32528443 PMCID: PMC7264269 DOI: 10.3389/fmicb.2020.01017] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Accepted: 04/24/2020] [Indexed: 12/18/2022] Open
Abstract
Azole resistance of the fungal pathogen Aspergillus fumigatus is an emerging problem. To identify novel mechanisms that could mediate azole resistance in A. fumigatus, we analyzed the transcriptome of a mitochondrial fission/fusion mutant that exhibits increased azole tolerance. Approximately 12% of the annotated genes are differentially regulated in this strain. This comprises upregulation of Cyp51A, the azole target structure, upregulation of ATP-binding cassette (ABC) superfamily and major facilitator superfamily (MFS) transporters and differential regulation of transcription factors. To study their impact on azole tolerance, conditional mutants were constructed of seven ABC transporters and 17 transcription factors. Under repressed conditions, growth rates and azole susceptibility of the mutants were similar to wild type. Under induced conditions, several transcription factor mutants showed growth phenotypes. In addition, four ABC transporter mutants and seven transcription factor mutants exhibited altered azole susceptibility. However, deletion of individual identified ABC transporters and transcription factors did not affect the increased azole tolerance of the fission/fusion mutant. Our results revealed the ability of multiple ABC transporters and transcription factors to modulate the azole susceptibility of A. fumigatus and support a model where mitochondrial dysfunctions trigger a drug resistance network that mediates azole tolerance of this mold.
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Affiliation(s)
- Laura Sturm
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Medizinische Fakultät, LMU München, Munich, Germany
| | - Bernadette Geißel
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Medizinische Fakultät, LMU München, Munich, Germany
| | - Ronny Martin
- Institut für Hygiene und Mikrobiologie, Julius-Maximilians-Universität Würzburg, Würzburg, Germany.,National Reference Center for Invasive Fungal Infections (NRZMyk), Jena, Germany
| | - Johannes Wagener
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Medizinische Fakultät, LMU München, Munich, Germany.,Institut für Hygiene und Mikrobiologie, Julius-Maximilians-Universität Würzburg, Würzburg, Germany.,National Reference Center for Invasive Fungal Infections (NRZMyk), Jena, Germany
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26
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Qiu W, Li J, Wei Y, Fan F, Jiang J, Liu M, Han X, Tian C, Zhang S, Zhuo R. Genome sequencing of Aspergillus glaucus 'CCHA' provides insights into salt-stress adaptation. PeerJ 2020; 8:e8609. [PMID: 32140304 PMCID: PMC7045888 DOI: 10.7717/peerj.8609] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 01/21/2020] [Indexed: 11/20/2022] Open
Abstract
Aspergillus, as a genus of filamentous fungi, has members that display a variety of different behavioural strategies, which are affected by various environmental factors. The decoded genomic sequences of many species vary greatly in their evolutionary similarities, encouraging studies on the functions and evolution of the Aspergillus genome in complex natural environments. Here, we present the 26 Mb de novo assembled high-quality reference genome of Aspergillus glaucus 'China Changchun halophilic Aspergillus' (CCHA), which was isolated from the surface of plants growing near a salt mine in Jilin, China, based on data from whole-genome shotgun sequencing using Illumina Solexa technology. The sequence, coupled with data from comprehensive transcriptomic survey analyses, indicated that the redox state and transmembrane transport might be critical molecular mechanisms for the adaptation of A. glaucus 'CCHA' to the high-salt environment of the saltern. The isolation of salt tolerance-related genes, such as CCHA-2114, and their overexpression in Escherichia coli demonstrated that A. glucus 'CCHA' is an excellent organism for the isolation and identification of salt tolerant-related genes. These data expand our understanding of the evolution and functions of fungal and microbial genomes, and offer multiple target genes for crop salt-tolerance improvement through genetic engineering.
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Affiliation(s)
- Wenmin Qiu
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing, China
- The Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou, Zhejiang, China
| | - Jingen Li
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Yi Wei
- College of Plant Sciences, Jilin University, Changchun, China
| | - Feiyu Fan
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Jing Jiang
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing, China
- The Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou, Zhejiang, China
| | - Mingying Liu
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing, China
- The Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou, Zhejiang, China
| | - Xiaojiao Han
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing, China
- The Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou, Zhejiang, China
| | - Chaoguang Tian
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Shihong Zhang
- College of Plant Sciences, Jilin University, Changchun, China
| | - Renying Zhuo
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing, China
- The Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou, Zhejiang, China
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27
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The Aspergillus fumigatus Phosphoproteome Reveals Roles of High-Osmolarity Glycerol Mitogen-Activated Protein Kinases in Promoting Cell Wall Damage and Caspofungin Tolerance. mBio 2020; 11:mBio.02962-19. [PMID: 32019798 PMCID: PMC7002344 DOI: 10.1128/mbio.02962-19] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Aspergillus fumigatus is an opportunistic human pathogen causing allergic reactions or systemic infections, such as invasive pulmonary aspergillosis in immunocompromised patients. The mitogen-activated protein kinase (MAPK) signaling pathways are essential for fungal adaptation to the human host. Fungal cell survival, fungicide tolerance, and virulence are highly dependent on the organization, composition, and function of the cell wall. Upon cell wall stress, MAPKs phosphorylate multiple target proteins involved in the remodeling of the cell wall. Here, we investigate the global phosphoproteome of the ΔsakA and ΔmpkCA. fumigatus and high-osmolarity glycerol (HOG) pathway MAPK mutants upon cell wall damage. This showed the involvement of the HOG pathway and identified novel protein kinases and transcription factors, which were confirmed by fungal genetics to be involved in promoting tolerance of cell wall damage. Our results provide understanding of how fungal signal transduction networks modulate the cell wall. This may also lead to the discovery of new fungicide drug targets to impact fungal cell wall function, fungicide tolerance, and virulence. The filamentous fungus Aspergillus fumigatus can cause a distinct set of clinical disorders in humans. Invasive aspergillosis (IA) is the most common life-threatening fungal disease of immunocompromised humans. The mitogen-activated protein kinase (MAPK) signaling pathways are essential to the adaptation to the human host. Fungal cell survival is highly dependent on the organization, composition, and function of the cell wall. Here, an evaluation of the global A. fumigatus phosphoproteome under cell wall stress caused by the cell wall-damaging agent Congo red (CR) revealed 485 proteins potentially involved in the cell wall damage response. Comparative phosphoproteome analyses with the ΔsakA, ΔmpkC, and ΔsakA ΔmpkC mutant strains from the osmotic stress MAPK cascades identify their additional roles during the cell wall stress response. Our phosphoproteomics allowed the identification of novel kinases and transcription factors (TFs) involved in osmotic stress and in the cell wall integrity (CWI) pathway. Our global phosphoproteome network analysis showed an enrichment for protein kinases, RNA recognition motif domains, and the MAPK signaling pathway. In contrast to the wild-type strain, there is an overall decrease of differentially phosphorylated kinases and phosphatases in ΔsakA, ΔmpkC, and ΔsakA ΔmpkC mutants. We constructed phosphomutants for the phosphorylation sites of several proteins differentially phosphorylated in the wild-type and mutant strains. For all the phosphomutants, there is an increase in the sensitivity to cell wall-damaging agents and a reduction in the MpkA phosphorylation upon CR stress, suggesting these phosphosites could be important for the MpkA modulation and CWI pathway regulation.
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28
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de Castro PA, Colabardini AC, Manfiolli AO, Chiaratto J, Silva LP, Mattos EC, Palmisano G, Almeida F, Persinoti GF, Ries LNA, Mellado L, Rocha MC, Bromley M, Silva RN, de Souza GS, Loures FV, Malavazi I, Brown NA, Goldman GH. Aspergillus fumigatus calcium-responsive transcription factors regulate cell wall architecture promoting stress tolerance, virulence and caspofungin resistance. PLoS Genet 2019; 15:e1008551. [PMID: 31887136 PMCID: PMC6948819 DOI: 10.1371/journal.pgen.1008551] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 01/08/2020] [Accepted: 12/02/2019] [Indexed: 11/28/2022] Open
Abstract
Aspergillus fumigatus causes invasive aspergillosis, the most common life-threatening fungal disease of immuno-compromised humans. The treatment of disseminated infections with antifungal drugs, including echinocandin cell wall biosynthesis inhibitors, is increasingly challenging due to the rise of drug-resistant pathogens. The fungal calcium responsive calcineurin-CrzA pathway influences cell morphology, cell wall composition, virulence, and echinocandin resistance. A screen of 395 A. fumigatus transcription factor mutants identified nine transcription factors important to calcium stress tolerance, including CrzA and ZipD. Here, comparative transcriptomics revealed CrzA and ZipD regulated the expression of shared and unique gene networks, suggesting they participate in both converged and distinct stress response mechanisms. CrzA and ZipD additively promoted calcium stress tolerance. However, ZipD also regulated cell wall organization, osmotic stress tolerance and echinocandin resistance. The absence of ZipD in A. fumigatus caused a significant virulence reduction in immunodeficient and immunocompetent mice. The ΔzipD mutant displayed altered cell wall organization and composition, while being more susceptible to macrophage killing and eliciting an increased pro-inflammatory cytokine response. A higher number of neutrophils, macrophages and activated macrophages were found in ΔzipD infected mice lungs. Collectively, this shows that ZipD-mediated regulation of the fungal cell wall contributes to the evasion of pro-inflammatory responses and tolerance of echinocandin antifungals, and in turn promoting virulence and complicating treatment options.
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Affiliation(s)
- Patrícia Alves de Castro
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Ana Cristina Colabardini
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Adriana Oliveira Manfiolli
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Jéssica Chiaratto
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Lilian Pereira Silva
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Eliciane Cevolani Mattos
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Giuseppe Palmisano
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Fausto Almeida
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Gabriela Felix Persinoti
- Laboratório Nacional de Biorrenováveis (LNBR), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, São Paulo, Brasil
| | - Laure Nicolas Annick Ries
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Laura Mellado
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Marina Campos Rocha
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, São Paulo, Brazil
| | - Michael Bromley
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester, United Kingdom
| | - Roberto Nascimento Silva
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Gabriel Scalini de Souza
- Instituto de Ciência e Tecnologia, Universidade Federal de São Paulo, São José dos Campos, Brazil
| | - Flávio Vieira Loures
- Instituto de Ciência e Tecnologia, Universidade Federal de São Paulo, São José dos Campos, Brazil
| | - Iran Malavazi
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, São Paulo, Brazil
| | - Neil Andrew Brown
- Department of Biology & Biochemistry, University of Bath, Claverton Down, Bath, United Kingdom
| | - Gustavo H Goldman
- Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
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A specific fungal transcription factor controls effector gene expression and orchestrates the establishment of the necrotrophic pathogen lifestyle on wheat. Sci Rep 2019; 9:15884. [PMID: 31685928 PMCID: PMC6828707 DOI: 10.1038/s41598-019-52444-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 10/17/2019] [Indexed: 12/14/2022] Open
Abstract
The fungus Parastagonospora nodorum infects wheat through the use of necrotrophic effector (NE) proteins that cause host-specific tissue necrosis. The Zn2Cys6 transcription factor PnPf2 positively regulates NE gene expression and is required for virulence on wheat. Little is known about other downstream targets of PnPf2. We compared the transcriptomes of the P. nodorum wildtype and a strain deleted in PnPf2 (pf2-69) during in vitro growth and host infection to further elucidate targets of PnPf2 signalling. Gene ontology enrichment analysis of the differentially expressed (DE) genes revealed that genes associated with plant cell wall degradation and proteolysis were enriched in down-regulated DE gene sets in pf2-69 compared to SN15. In contrast, genes associated with redox control, nutrient and ion transport were up-regulated in the mutant. Further analysis of the DE gene set revealed that PnPf2 positively regulates twelve genes that encode effector-like proteins. Two of these genes encode proteins with homology to previously characterised effectors in other fungal phytopathogens. In addition to modulating effector gene expression, PnPf2 may play a broader role in the establishment of a necrotrophic lifestyle by orchestrating the expression of genes associated with plant cell wall degradation and nutrient assimilation.
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30
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Király A, Hámori C, Gyémánt G, Kövér KE, Pócsi I, Leiter É. Characterization of gfdB, putatively encoding a glycerol 3-phosphate dehydrogenase in Aspergillus nidulans. Fungal Biol 2019; 124:352-360. [PMID: 32389297 DOI: 10.1016/j.funbio.2019.09.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 09/26/2019] [Accepted: 09/28/2019] [Indexed: 11/18/2022]
Abstract
The genome of Aspergillus nidulans accommodates two glycerol 3-phosphate dehydrogenase genes, gfdA and gfdB. Previous studies confirmed that GfdA is involved in the osmotic stress defence of the fungus. In this work, the physiological role of GfdB was characterized via the construction and functional characterization of the gene deletion mutant ΔgfdB. Unexpectedly, ΔgfdB strains showed oxidative stress sensitivity in the presence of a series of well-known oxidants including tert-butyl-hydroperoxide (tBOOH), diamide as well as hydrogen peroxide. Moderate sensitivity of the mutant towards the cell wall stress inducing agent CongoRed was also observed. Hence, both Gfd isoenzymes contributed to the environmental stress defence of the fungus but their functions were stress-type-specific. Furthermore, the specific activities of certain antioxidant enzymes, like catalase and glutathione peroxidase, were lower in ΔgfdB hyphae than those recorded in the control strain. As a consequence, mycelia from ΔgfdB cultures accumulated reactive species at higher levels than the control. On the other hand, the specific glutathione reductase activity was higher in the mutant, most likely to compensate for the elevated intracellular oxidative species concentrations. Nevertheless, the efficient control of reactive species failed in ΔgfdB cultures, which resulted in reduced viability and, concomitantly, early onset of programmed cell death in mutant hyphae. Inactivation of gfdB brought about higher mannitol accumulation in mycelia meanwhile the erythritol production was not disturbed in unstressed cultures. After oxidative stress treatment with tBOOH, only mannitol was detected in both mutant and control mycelia and the accumulation of mannitol even intensified in the ΔgfdB strain.
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Affiliation(s)
- Anita Király
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary; University of Debrecen, Pál Juhász-Nagy Doctoral School of Biology and Environmental Sciences, Hungary
| | - Csaba Hámori
- Department of Inorganic and Analytical Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Gyöngyi Gyémánt
- Department of Inorganic and Analytical Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Katalin E Kövér
- Department of Inorganic and Analytical Chemistry, 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
| | - Éva Leiter
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary.
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31
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Day AM, Quinn J. Stress-Activated Protein Kinases in Human Fungal Pathogens. Front Cell Infect Microbiol 2019; 9:261. [PMID: 31380304 PMCID: PMC6652806 DOI: 10.3389/fcimb.2019.00261] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 07/04/2019] [Indexed: 11/28/2022] Open
Abstract
The ability of fungal pathogens to survive hostile environments within the host depends on rapid and robust stress responses. Stress-activated protein kinase (SAPK) pathways are conserved MAPK signaling modules that promote stress adaptation in all eukaryotic cells, including pathogenic fungi. Activation of the SAPK occurs via the dual phosphorylation of conserved threonine and tyrosine residues within a TGY motif located in the catalytic domain. This induces the activation and nuclear accumulation of the kinase and the phosphorylation of diverse substrates, thus eliciting appropriate cellular responses. The Hog1 SAPK has been extensively characterized in the model yeast Saccharomyces cerevisiae. Here, we use this a platform from which to compare SAPK signaling mechanisms in three major fungal pathogens of humans, Candida albicans, Aspergillus fumigatus, and Cryptococcus neoformans. Despite the conservation of SAPK pathways within these pathogenic fungi, evidence is emerging that their role and regulation has significantly diverged. However, consistent with stress adaptation being a common virulence trait, SAPK pathways are important pathogenicity determinants in all these major human pathogens. Thus, the development of drugs which target fungal SAPKs has the exciting potential to generate broad-acting antifungal treatments.
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Affiliation(s)
- Alison M Day
- Faculty of Medicine, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Janet Quinn
- Faculty of Medicine, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle Upon Tyne, United Kingdom
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32
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Fabri JHTM, Rocha MC, Malavazi I. Overview of the Interplay Between Cell Wall Integrity Signaling Pathways and Membrane Lipid Biosynthesis in Fungi: Perspectives for Aspergillus fumigatus. Curr Protein Pept Sci 2019; 21:265-283. [PMID: 31284857 DOI: 10.2174/1389203720666190705164203] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 06/10/2019] [Accepted: 06/13/2019] [Indexed: 11/22/2022]
Abstract
The cell wall (CW) and plasma membrane are fundamental structures that define cell shape and support different cellular functions. In pathogenic fungi, such as Aspegillus fumigatus, they not only play structural roles but are also important for virulence and immune recognition. Both the CW and the plasma membrane remain as attractive drug targets to treat fungal infections, such as the Invasive Pulmonary Aspergillosis (IPA), a disease associated with high morbimortality in immunocompromised individuals. The low efficiency of echinocandins that target the fungal CW biosynthesis, the occurrence of environmental isolates resistant to azoles such as voriconazole and the known drawbacks associated with amphotericin toxicity foster the urgent need for fungal-specific drugable targets and/or more efficient combinatorial therapeutic strategies. Reverse genetic approaches in fungi unveil that perturbations of the CW also render cells with increased susceptibility to membrane disrupting agents and vice-versa. However, how the fungal cells simultaneously cope with perturbation in CW polysaccharides and cell membrane proteins to allow morphogenesis is scarcely known. Here, we focus on current information on how the main signaling pathways that maintain fungal cell wall integrity, such as the Cell Wall Integrity and the High Osmolarity Glycerol pathways, in different species often cross-talk to regulate the synthesis of molecules that comprise the plasma membrane, especially sphingolipids, ergosterol and phospholipids to promote functioning of both structures concomitantly and thus, cell viability. We propose that the conclusions drawn from other organisms are the foundations to point out experimental lines that can be endeavored in A. fumigatus.
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Affiliation(s)
| | - Marina C Rocha
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, Brazil
| | - Iran Malavazi
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, Brazil
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33
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Antsotegi-Uskola M, Markina-Iñarrairaegui A, Ugalde U. New insights into copper homeostasis in filamentous fungi. Int Microbiol 2019; 23:65-73. [PMID: 31093811 PMCID: PMC6981102 DOI: 10.1007/s10123-019-00081-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 04/15/2019] [Accepted: 04/23/2019] [Indexed: 01/06/2023]
Abstract
Copper is a metal ion that is required as a micronutrient for growth and proliferation. However, copper accumulation generates toxicity by multiple mechanisms, potentially leading to cell death. Due to its toxic nature at high concentrations, different chemical variants of copper have been extensively used as antifungal agents in agriculture and medicine. Most studies on copper homeostasis have been carried out in bacteria, yeast, and mammalian organisms. However, knowledge on filamentous fungi is less well documented. This review summarizes the knowledge gathered in the last few years about copper homeostasis in the filamentous fungi Aspergillus fumigatus and Aspergillus nidulans: The mechanism of action of copper, the uptake and detoxification systems, their regulation at the transcriptional level, and the role of copper homeostasis in fungal pathogenicity are presented.
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Affiliation(s)
- Martzel Antsotegi-Uskola
- Microbial Biochemistry Laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of the Basque Country, San Sebastian, Spain
| | - Ane Markina-Iñarrairaegui
- Microbial Biochemistry Laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of the Basque Country, San Sebastian, Spain
| | - Unai Ugalde
- Microbial Biochemistry Laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of the Basque Country, San Sebastian, Spain.
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34
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Fabri JHTM, Godoy NL, Rocha MC, Munshi M, Cocio TA, von Zeska Kress MR, Fill TP, da Cunha AF, Del Poeta M, Malavazi I. The AGC Kinase YpkA Regulates Sphingolipids Biosynthesis and Physically Interacts With SakA MAP Kinase in Aspergillus fumigatus. Front Microbiol 2019; 9:3347. [PMID: 30692984 PMCID: PMC6339957 DOI: 10.3389/fmicb.2018.03347] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 12/28/2018] [Indexed: 12/12/2022] Open
Abstract
Sphingolipids (SL) are complex lipids and components of the plasma membrane which are involved in numerous cellular processes, as well as important for virulence of different fungal pathogens. In yeast, SL biosynthesis is regulated by the "AGC kinases" Ypk1 and Ypk2, which also seem to connect the SL biosynthesis with the cell wall integrity (CWI) and the High Osmolarity Glycerol (HOG) pathways. Here, we investigate the role of ypkA Y PK1 in SL biosynthesis and its relationship with the CWI and the HOG pathways in the opportunistic human pathogen Aspergillus fumigatus. We found that ypkA is important for fungal viability, since the ΔypkA strain presented a drastically sick phenotype and complete absence of conidiation. We observed that under repressive condition, the conditional mutant niiA::ypkA exhibited vegetative growth defects, impaired germination and thermosensitivity. In addition, the ypkA loss of function caused a decrease in glycosphingolipid (GSL) levels, especially the metabolic intermediates belonging to the neutral GSL branch including dihydroceramide (DHC), ceramide (Cer), and glucosylceramide (GlcCer), but interestingly a small increase in ergosterol content. Genetic analyzes showed that ypkA genetically interacts with the MAP kinases of CWI and HOG pathways, mpkA and sakA, respectively, while only SakA physically interacts with YpkA. Our results suggest that YpkA is important for fungal survival through the regulation of GSL biosynthesis and cross talks with A. fumigatus MAP kinase pathways.
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Affiliation(s)
| | - Naiane Lima Godoy
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, Brazil
| | - Marina Campos Rocha
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, Brazil
| | - Mansa Munshi
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY, United States
| | - Tiago Alexandre Cocio
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, Brazil
| | - Marcia Regina von Zeska Kress
- Departamento de Análises Clínicas Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | | | - Anderson Ferreira da Cunha
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, Brazil
| | - Maurizio Del Poeta
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY, United States.,Division of Infectious Diseases, School of Medicine, Stony Brook University, Stony Brook, NY, United States.,Institute of Chemical Biology and Drug Discovery, Stony Brook University, Stony Brook, NY, United States.,Veterans Administration Medical Center, Northport, NY, United States
| | - Iran Malavazi
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, Brazil
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Tumukunde E, Li D, Qin L, Li Y, Shen J, Wang S, Yuan J. Osmotic-Adaptation Response of sakA/hogA Gene to Aflatoxin Biosynthesis, Morphology Development and Pathogenicity in Aspergillus flavus. Toxins (Basel) 2019; 11:toxins11010041. [PMID: 30646608 PMCID: PMC6356625 DOI: 10.3390/toxins11010041] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 12/19/2018] [Accepted: 01/11/2019] [Indexed: 02/06/2023] Open
Abstract
Aspergillus flavus is one of the fungi from the big family of Aspergillus genus and it is capable of colonizing a large number of seed/crops and living organisms such as animals and human beings. SakA (also called hogA/hog1) is an integral part of the mitogen activated protein kinase signal of the high osmolarity glycerol pathway. In this study, the AfsakA gene was deleted (∆AfsakA) then complemented (∆AfsakA::AfsakA) using homologous recombination and the osmotic stress was induced by 1.2 mol/L D-sorbital and 1.2 mol/L sodium chloride. The result showed that ∆AfsakA mutant caused a significant influence on conidial formation compared to wild-type and ∆AfsakA::AfsakA strains. It was also found that AfsakA responds to both the osmotic stress and the cell wall stress. In the absence of osmotic stress, ∆AfsakA mutant produced more sclerotia in contrast to other strains, whereas all strains failed to generate sclerotia under osmotic stress. Furthermore, the deletion of AfsakA resulted in the increase of Aflatoxin B1 production compared to other strains. The virulence assay on both maize kernel and peanut seeds showed that ∆AfsakA strain drastically produced more conidia and Aflatoxin B1 than wild-type and complementary strains. AfSakA-mCherry was located to the cytoplasm in the absence of osmotic stress, while it translocated to the nucleus upon exposure to the osmotic stimuli. This study provides new insights on the development and evaluation of aflatoxin biosynthesis and also provides better understanding on how to prevent Aspergillus infections which would be considered the first step towards the prevention of the seeds damages caused by A. flavus.
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Affiliation(s)
- Elisabeth Tumukunde
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Ministry of Education and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Ding Li
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Ministry of Education and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Ling Qin
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Ministry of Education and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Yu Li
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Ministry of Education and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Jiaojiao Shen
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Ministry of Education and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Shihua Wang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Ministry of Education and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Jun Yuan
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Ministry of Education and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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de Assis LJ, Manfiolli A, Mattos E, Fabri JHTM, Malavazi I, Jacobsen ID, Brock M, Cramer RA, Thammahong A, Hagiwara D, Ries LNA, Goldman GH. Protein Kinase A and High-Osmolarity Glycerol Response Pathways Cooperatively Control Cell Wall Carbohydrate Mobilization in Aspergillus fumigatus. mBio 2018; 9:e01952-18. [PMID: 30538182 PMCID: PMC6299480 DOI: 10.1128/mbio.01952-18] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 11/06/2018] [Indexed: 02/07/2023] Open
Abstract
Aspergillus fumigatus mitogen-activated protein kinases (MAPKs) are involved in maintaining the normal morphology of the cell wall and providing resistance against cell wall-damaging agents. Upon cell wall stress, cell wall-related sugars need to be synthesized from carbohydrate storage compounds. Here we show that this process is dependent on cAMP-dependent protein kinase A (PKA) activity and regulated by the high-osmolarity glycerol response (HOG) MAPKs SakA and MpkC. These protein kinases are necessary for normal accumulation/degradation of trehalose and glycogen, and the lack of these genes reduces glucose uptake and glycogen synthesis. Alterations in glycogen synthesis were observed for the sakA and mpkC deletion mutants, which also displayed alterations in carbohydrate exposure on the cell wall. Carbohydrate mobilization is controlled by SakA interaction with PkaC1 and PkaR, suggesting a putative mechanism where the PkaR regulatory subunit leaves the complex and releases the SakA-PkaC1 complex for activation of enzymes involved in carbohydrate mobilization. This work reveals the communication between the HOG and PKA pathways for carbohydrate mobilization for cell wall construction.IMPORTANCEAspergillus fumigatus is an opportunistic human pathogen causing allergic reactions or systemic infections such as invasive pulmonary aspergillosis, especially in immunocompromised patients. The fungal cell wall is the main component responsible for recognition by the immune system, due to the specific composition of polysaccharide carbohydrates exposed on the surface of the fungal cell wall called pathogen-associated molecular patterns (PAMPs). Key enzymes in the fungal cell wall biosynthesis are a good target for fungal drug development. This report elucidates the cooperation between the HOG and PKA pathways in the mobilization of carbohydrates for fungal cell wall biosynthesis. We suggest that the reduced mobilization of simple sugars causes defects in the structure of the fungal cell wall. In summary, we propose that SakA is important for PKA activity, therefore regulating the availability and mobilization of monosaccharides for fungal cell wall biosynthesis during cell wall damage and the osmotic stress response.
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Affiliation(s)
- Leandro José de Assis
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Adriana Manfiolli
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Eliciane Mattos
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - João H T Marilhano Fabri
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Paulo, Brazil
| | - Iran Malavazi
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Paulo, Brazil
| | - Ilse D Jacobsen
- Research Group Microbial Immunology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Matthias Brock
- Fungal Genetics and Biology Group, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Robert A Cramer
- Geisel School of Medicine at Dartmouth, Department of Microbiology and Immunology, Hanover, New Hampshire, USA
| | - Arsa Thammahong
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Daisuke Hagiwara
- Faculty of Life and Environmental Sciences, University of Tsukuba, Ibaraki, Japan
| | | | - Gustavo Henrique Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
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Emri T, Antal K, Riley R, Karányi Z, Miskei M, Orosz E, Baker S, Wiebenga A, de Vries R, Pócsi I. Duplications and losses of genes encoding known elements of the stress defence system of the Aspergilli contribute to the evolution of these filamentous fungi but do not directly influence their environmental stress tolerance. Stud Mycol 2018; 91:23-36. [PMID: 30425415 PMCID: PMC6231086 DOI: 10.1016/j.simyco.2018.10.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The contribution of stress protein duplication and deletion events to the evolution of the Aspergilli was studied. We performed a large-scale homology analysis of stress proteins and generated and analysed three stress defence system models based on Saccharomyces cerevisiae, Schizosaccharomyces pombe and Aspergillus nidulans. Although both yeast-based and A. nidulans-based models were suitable to trace evolutionary changes, the A. nidulans-based model performed better in mapping stress protein radiations. The strong Mantel correlation found between the positions of species in the phylogenetic tree on the one hand and either in the A. nidulans-based or S. cerevisiae-based models on the other hand demonstrated that stress protein expansions and reductions contributed significantly to the evolution of the Aspergilli. Interestingly, stress tolerance attributes correlated well with the number of orthologs only for a few stress proteins. Notable examples are Ftr1 iron permease and Fet3 ferro-O2-oxidoreductase, elements of the reductive iron assimilation pathway, in the S. cerevisiae-based model, as well as MpkC, a HogA-like mitogen activated protein kinase in the A. nidulans-based model. In the case of the iron assimilation proteins, the number of orthologs showed a positive correlation with H2O2-induced stress tolerance while the number of MpkC orthologs correlated positively with Congo Red induced cell wall stress, sorbitol induced osmotic stress and H2O2 induced oxidative stress tolerances. For most stress proteins, changes in the number of orthologs did not correlate well with any stress tolerance attributes. As a consequence, stress tolerance patterns of the studied Aspergilli did not correlate with either the sets of stress response proteins in general or with the phylogeny of the species studied. These observations suggest that stress protein duplication and deletion events significantly contributed to the evolution of stress tolerance attributes of Aspergilli. In contrast, there are other processes, which may counterbalance the effects of stress gene duplications or deletions including (i) alterations in the structures of stress proteins leading to changes in their biological activities, (ii) varying biosynthesis of stress proteins, (iii) rewiring stress response regulatory networks or even (iv) acquiring new stress response genes by horizontal gene transfer. All these multilevel changes are indispensable for the successful adaptation of filamentous fungi to altering environmental conditions, especially when these organisms are entering new ecological niches.
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Affiliation(s)
- T. Emri
- Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, H-4032, Debrecen, Hungary
| | - K. Antal
- Department of Zoology, Faculty of Sciences, Eszterházy Károly University, Eszterházy tér 1., H-3300, Eger, Hungary
| | - R. Riley
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA
| | - Z. Karányi
- Department of Medicine, Faculty of Medicine, University of Debrecen, Nagyerdei krt. 98, H-4032, Debrecen, Hungary
| | - M. Miskei
- Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, H-4032, Debrecen, Hungary
- MTA-DE Momentum, Laboratory of Protein Dynamics, Department of Biochemistry and Molecular Biology, University of Debrecen, Nagyerdei krt. 98, H-4032, Debrecen, Hungary
| | - E. Orosz
- Department of Biotechnology and Microbiology, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, H-4032, Debrecen, Hungary
| | - S.E. Baker
- Environmental Molecular Sciences Division, Earth and Biological Sciences, Pacific Northwest National Laboratory, Richland, Washington, 99352, USA
| | - A. Wiebenga
- Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584 CT, Utrecht, the Netherlands
- Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands
| | - R.P. de Vries
- Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584 CT, Utrecht, the Netherlands
- Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands
| | - I. 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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Zhang C, Meng X, Gu H, Ma Z, Lu L. Predicted Glycerol 3-Phosphate Dehydrogenase Homologs and the Glycerol Kinase GlcA Coordinately Adapt to Various Carbon Sources and Osmotic Stress in Aspergillus fumigatus. G3 (BETHESDA, MD.) 2018; 8:2291-2299. [PMID: 29739860 PMCID: PMC6027872 DOI: 10.1534/g3.118.200253] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Accepted: 05/03/2018] [Indexed: 01/01/2023]
Abstract
Glycerol plays an important role in the adaptation of fungi to various microenvironments and stressors, including heat shock, anoxic conditions and osmotic stress. Glycerol 3-phosphate dehydrogenase (G3PDH) is able to catalyze dihydroxyacetone phosphate to glycerol 3-phosphate (G3P), which is subsequently dephosphorylated into glycerol. However, current knowledge about the functions of G3PDH homologs in glycerol biosynthesis in Aspergillus fumigatus is limited. Here, we show that the A. fumigatus G3PDH gene, gfdA, is crucial for normal colony growth in glucose media under both normoxic and hypoxic conditions. In addition, failure of the overexpression of the gfdA homolog, gfdB, to rescue the phenotype of a gfdA null mutant suggests that gfdA plays a predominant role in the synthesis of G3P and glycerol. However, in a wild-type background, overexpressing either gfdA or gfdB is able to significantly enhance biomass production of mycelia, suggesting that gfdA and gfdB have similar functions in promoting the use of glucose. Interestingly, overexpression of the gene encoding the predicted glycerol kinase, GlcA, which is capable of phosphorylating glycerol to form G3P, significantly rescues the growth defects of gfdA null mutants in glucose media, indicating that the growth defects of gfdA null mutants might be due to the absence of G3P rather than glycerol. Moreover, Western blotting analysis revealed that gfdA is inducibly expressed by osmotic mediators. However, in the absence of gfdA, osmotic stress can rescue colony growth defects and allow colonies to partially bypass the gfdA requirement in a high osmolarity glycerol pathway-dependent manner. Therefore, the findings of this study elucidate how saprophytic filamentous fungi have developed pathways distinct from those of budding yeasts to adapt to varied carbon sources and survive environmental stresses.
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Affiliation(s)
- Chi Zhang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Xiuhua Meng
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Huiyu Gu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Zhihua Ma
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Ling Lu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
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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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Wiemann P, Perevitsky A, Lim FY, Shadkchan Y, Knox BP, Landero Figueora JA, Choera T, Niu M, Steinberger AJ, Wüthrich M, Idol RA, Klein BS, Dinauer MC, Huttenlocher A, Osherov N, Keller NP. Aspergillus fumigatus Copper Export Machinery and Reactive Oxygen Intermediate Defense Counter Host Copper-Mediated Oxidative Antimicrobial Offense. Cell Rep 2018; 19:1008-1021. [PMID: 28467895 DOI: 10.1016/j.celrep.2017.04.019] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 03/13/2017] [Accepted: 04/06/2017] [Indexed: 12/23/2022] Open
Abstract
The Fenton-chemistry-generating properties of copper ions are considered a potent phagolysosome defense against pathogenic microbes, yet our understanding of underlying host/microbe dynamics remains unclear. We address this issue in invasive aspergillosis and demonstrate that host and fungal responses inextricably connect copper and reactive oxygen intermediate (ROI) mechanisms. Loss of the copper-binding transcription factor AceA yields an Aspergillus fumigatus strain displaying increased sensitivity to copper and ROI in vitro, increased intracellular copper concentrations, decreased survival in challenge with murine alveolar macrophages (AMΦs), and reduced virulence in a non-neutropenic murine model. ΔaceA survival is remediated by dampening of host ROI (chemically or genetically) or enhancement of copper-exporting activity (CrpA) in A. fumigatus. Our study exposes a complex host/microbe multifactorial interplay that highlights the importance of host immune status and reveals key targetable A. fumigatus counter-defenses.
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Affiliation(s)
- Philipp Wiemann
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA
| | - Adi Perevitsky
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Fang Yun Lim
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA
| | - Yana Shadkchan
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Benjamin P Knox
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA
| | - Julio A Landero Figueora
- University of Cincinnati/Agilent Technologies Metallomics Center of the Americas, Department of Chemistry, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Tsokyi Choera
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA
| | - Mengyao Niu
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA
| | | | - Marcel Wüthrich
- Department of Pediatrics, University of Wisconsin, Madison, WI 53706, USA
| | - Rachel A Idol
- Department of Pediatrics, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
| | - Bruce S Klein
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA; Department of Pediatrics, University of Wisconsin, Madison, WI 53706, USA; Department of Medicine, University of Wisconsin, Madison, WI 53706, USA
| | - Mary C Dinauer
- Department of Pediatrics, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA; Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
| | - Anna Huttenlocher
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, USA; Department of Pediatrics, University of Wisconsin, Madison, WI 53706, USA
| | - Nir Osherov
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel.
| | - 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.
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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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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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The Hog1-like MAPK Mpk3 collaborates with Hog1 in response to heat shock and functions in sustaining the biological control potential of a fungal insect pathogen. Appl Microbiol Biotechnol 2017; 101:6941-6949. [DOI: 10.1007/s00253-017-8434-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 07/09/2017] [Accepted: 07/19/2017] [Indexed: 12/27/2022]
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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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The Aspergillus fumigatus CrzA Transcription Factor Activates Chitin Synthase Gene Expression during the Caspofungin Paradoxical Effect. mBio 2017; 8:mBio.00705-17. [PMID: 28611248 PMCID: PMC5472186 DOI: 10.1128/mbio.00705-17] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Aspergillus fumigatus is an opportunistic fungal pathogen that causes invasive aspergillosis (IA), a life-threatening disease in immunocompromised humans. The echinocandin caspofungin, adopted as a second-line therapy in combating IA, is a β-1,3-glucan synthase inhibitor, which, when used in high concentrations, reverts the anticipated A. fumigatus growth inhibition, a phenomenon called the “caspofungin paradoxical effect” (CPE). The CPE has been widely associated with increased chitin content in the cell wall due to a compensatory upregulation of chitin synthase-encoding genes. Here, we demonstrate that the CPE is dependent on the cell wall integrity (CWI) mitogen-activated protein kinase MpkAMPK1 and its associated transcription factor (TF) RlmARLM1, which regulate chitin synthase gene expression in response to different concentrations of caspofungin. Furthermore, the calcium- and calcineurin-dependent TF CrzA binds to and regulates the expression of specific chitin synthase genes during the CPE. These results suggest that the regulation of cell wall biosynthetic genes occurs by several cellular signaling pathways. In addition, CrzA is also involved in cell wall organization in the absence of caspofungin. Differences in the CPE were also observed between two A. fumigatus clinical isolates, which led to the identification of a novel basic leucine zipper TF, termed ZipD. This TF functions in the calcium-calcineurin pathway and is involved in the regulation of cell wall biosynthesis genes. This study therefore unraveled additional mechanisms and novel factors governing the CPE response, which ultimately could aid in developing more effective antifungal therapies. Systemic Aspergillus fumigatus infections are often accompanied by high mortality rates. The fungal cell wall is important for infection as it has immunomodulatory and immunoevasive properties. Paradoxical growth of A. fumigatus in the presence of high concentrations of the cell wall-disturbing agent caspofungin has been observed for more than a decade, although the mechanistic nature of this phenomenon remains largely uncharacterized. Here, we show that the CWI pathway components MpkA and RlmA as well as the calcium/calcineurin-responsive transcription factor CrzA regulate the expression of cell wall biosynthetic genes during the caspofungin paradoxical effect (CPE). Furthermore, an additional, novel calcium/calcineurin-responsive transcription factor was identified to play a role in cell wall biosynthesis gene expression during the CPE. This work paints a crucial role for calcium metabolism in the CPE and provides further insight into the complex regulation of cell wall biosynthesis, which could ultimately lead to the development of more efficient antifungal therapies.
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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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