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Edrich ESM, Duvenage L, Gourlay CW. Alternative Oxidase - Aid or obstacle to combat the rise of fungal pathogens? Biochim Biophys Acta Bioenerg 2024; 1865:149031. [PMID: 38195037 DOI: 10.1016/j.bbabio.2024.149031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 11/16/2023] [Accepted: 01/03/2024] [Indexed: 01/11/2024]
Abstract
Fungal pathogens present a growing threat to both humans and global health security alike. Increasing evidence of antifungal resistance in fungal populations that infect both humans and plant species has increased reliance on combination therapies and shown the need for new antifungal therapeutic targets to be investigated. Here, we review the roles of mitochondria and fungal respiration in pathogenesis and discuss the role of the Alternative Oxidase enzyme (Aox) in both human fungal pathogens and phytopathogens. Increasing evidence exists for Aox within mechanisms that underpin fungal virulence. Aox also plays important roles in adaptability that may prove useful within dual targeted fungal-specific therapeutic approaches. As improved fungal specific mitochondrial and Aox inhibitors are under development we may see this as an emerging target for future approaches to tackling the growing challenge of fungal infection.
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Affiliation(s)
| | - Lucian Duvenage
- CMM AFRICA Medical Mycology Research Unit, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Campbell W Gourlay
- Kent Fungal Group, School of Biosciences, University of Kent, Kent CT2 9HY, UK.
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2
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Thorn V, Xu J. Mitogenome Variations in a Global Population of Aspergillus fumigatus. J Fungi (Basel) 2023; 9:995. [PMID: 37888251 PMCID: PMC10608017 DOI: 10.3390/jof9100995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 10/05/2023] [Accepted: 10/06/2023] [Indexed: 10/28/2023] Open
Abstract
Aspergillus fumigatus is a ubiquitous, critical priority human fungal pathogen. Despite its clinical importance, there is limited knowledge regarding the variations of the genome within mitochondria, the powerhouse organelle within eukaryotic cells. In this study, we leveraged publicly available, raw, whole genome sequence data isolates from 1939 to investigate the variations in the mitochondrial genomes of A. fumigatus. These isolates were isolated from 22 countries on six continents, as well as from outer space and from within the International Space Station. In total, our analysis revealed 39 mitochondrial single nucleotide polymorphisms (mtSNPs) within this global sample, and, together, these 39 mtSNPs grouped the 1939 isolates into 79 mitochondrial multilocus genotypes (MLGs). Among the 79 MLGs, 39 were each distributed in at least two countries and 30 were each shared by at least two continents. The two most frequent MLGs were also broadly distributed: MLG11 represented 420 isolates from 11 countries and four continents and while MLG79 represented 418 isolates from 18 countries and five continents, consistent with long-distance dispersals of mitogenomes. Our population genetic analyses of the mtSNPs revealed limited differentiation among continental populations, but highly variable genetic differences among national populations, largely due to localized clonal expansions of different MLGs. Phylogenetic analysis and Discriminant Analysis of Principal Components of mtSNPs suggested the presence of at least three mitogenome clusters. Linkage disequilibrium, Index of Association, and phylogenetic incompatibility analyses collectively suggested evidence for mitogenome recombination in natural populations of A. fumigatus. In addition, sequence read depth analyses revealed an average ratio of ~20 mitogenomes per nuclear genome in this global population, but the ratios varied among strains within and between certain geographic populations. Together, our results suggest evidence for organelle dynamics, genetic differentiation, recombination, and both widespread and localized clonal expansion of the mitogenomes in the global A. fumigatus population.
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Affiliation(s)
| | - Jianping Xu
- Department of Biology, Institute of Infectious Diseases Research, McMaster University, Hamilton, ON L8S 4K1, Canada;
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3
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El-Khoury R, Rak M, Bénit P, Jacobs HT, Rustin P. Cyanide resistant respiration and the alternative oxidase pathway: A journey from plants to mammals. Biochim Biophys Acta Bioenerg 2022; 1863:148567. [PMID: 35500614 DOI: 10.1016/j.bbabio.2022.148567] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 04/06/2022] [Accepted: 04/18/2022] [Indexed: 12/19/2022]
Abstract
In a large number of organisms covering all phyla, the mitochondrial respiratory chain harbors, in addition to the conventional elements, auxiliary proteins that confer adaptive metabolic plasticity. The alternative oxidase (AOX) represents one of the most studied auxiliary proteins, initially identified in plants. In contrast to the standard respiratory chain, the AOX mediates a thermogenic cyanide-resistant respiration; a phenomenon that has been of great interest for over 2 centuries in that energy is not conserved when electrons flow through it. Here we summarize centuries of studies starting from the early observations of thermogenicity in plants and the identification of cyanide resistant respiration, to the fascinating discovery of the AOX and its current applications in animals under normal and pathological conditions.
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Affiliation(s)
- Riyad El-Khoury
- American University of Beirut Medical Center, Pathology and Laboratory Medicine Department, Cairo Street, Hamra, Beirut, Lebanon
| | - Malgorzata Rak
- Université Paris Cité, Inserm, Maladies neurodéveloppementales et neurovasculaires, F-75019 Paris, France
| | - Paule Bénit
- Université Paris Cité, Inserm, Maladies neurodéveloppementales et neurovasculaires, F-75019 Paris, France
| | - Howard T Jacobs
- Faculty of Medicine and Health Technology, FI-33014, Tampere University, Finland; Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
| | - Pierre Rustin
- Université Paris Cité, Inserm, Maladies neurodéveloppementales et neurovasculaires, F-75019 Paris, France.
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Szibor M, Schenkl C, Barsottini MRO, Young L, Moore AL. Targeting the alternative oxidase (AOX) for human health and food security, a pharmaceutical and agrochemical target or a rescue mechanism? Biochem J 2022; 479:1337-59. [PMID: 35748702 DOI: 10.1042/BCJ20180192] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 05/23/2022] [Accepted: 06/07/2022] [Indexed: 11/25/2022]
Abstract
Some of the most threatening human diseases are due to a blockage of the mitochondrial electron transport chain (ETC). In a variety of plants, fungi, and prokaryotes, there is a naturally evolved mechanism for such threats to viability, namely a bypassing of the blocked portion of the ETC by alternative enzymes of the respiratory chain. One such enzyme is the alternative oxidase (AOX). When AOX is expressed, it enables its host to survive life-threatening conditions or, as in parasites, to evade host defenses. In vertebrates, this mechanism has been lost during evolution. However, we and others have shown that transfer of AOX into the genome of the fruit fly and mouse results in a catalytically engaged AOX. This implies that not only is the AOX a promising target for combating human or agricultural pathogens but also a novel approach to elucidate disease mechanisms or, in several cases, potentially a therapeutic cure for human diseases. In this review, we highlight the varying functions of AOX in their natural hosts and upon xenotopic expression, and discuss the resulting need to develop species-specific AOX inhibitors.
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5
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Jiang N, Li SZ, Zhang YWQ, Habib MR, Xiong T, Xu S, Dong H, Zhao QP. The identification of alternative oxidase in intermediate host snails of Schistosoma and its potential role in protecting Oncomelania hupensis against niclosamide-induced stress. Parasit Vectors 2022; 15:97. [PMID: 35313980 PMCID: PMC8935807 DOI: 10.1186/s13071-022-05227-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 03/03/2022] [Indexed: 11/21/2022] Open
Abstract
Background Snail intermediate hosts are mandatory for the transmission of schistosomiasis, which has to date infected more than 200 million people worldwide. Our previous studies showed that niclosamide treatment caused the inhibition of aerobic respiration and oxidative phosphorylation, and the disruption of energy supply, in one of the intermediate hosts of schistosomiasis, Oncomelania hupensis, which eventually led to the death of the snails. Meanwhile, the terminal oxidase in the mitochondrial respiratory chain, alternative oxidase (AOX), was significantly up-regulated, which was thought to counterbalance the oxidative stress and maintain metabolic homeostasis in the snails. The aims of the present study are to identify the AOXs in several species of snails and investigate the potential activation of O. hupensis AOX (OhAOX) under niclosamide-induced stress, leading to enhanced survival of the snail when exposed to this molluscicide. Methods The complete complementary DNA was amplified from the AOXs of O. hupensis and three species of Biomphalaria; the sequence characteristics were analysed and the phylogenetics investigated. The dynamic expression and localisation of the AOX gene and protein in O. hupensis under niclosamide-induced stress were examined. In addition, the expression pattern of genes in the mitochondrial respiratory complex was determined and the production of reactive oxygen species (ROS) calculated. Finally, the molluscicidal effect of niclosamide was compared between snails with and without inhibition of AOX activity. Results AOXs containing the invertebrate AOX-specific motif NP-[YF]-XPG-[KQE] were identified from four species of snail, which phylogenetically clustered together into Gastropoda AOXs and further into Mollusca AOXs. After niclosamide treatment, the levels of OhAOX messenger RNA (mRNA) and OhAOX protein in the whole snail were 14.8 and 2.6 times those in untreated snails, respectively, but varied widely among tissues. Meanwhile, the level of cytochrome C reductase mRNA showed a significant decrease in the whole snail, and ROS production showed a significant decrease in the liver plus gonad (liver-gonad) of the snails. At 24 h post-treatment, the mortality of snails treated with 0.06–0.1 mg/L niclosamide and AOX inhibitor was 56.31–76.12% higher than that of snails treated with 0.1 mg/L niclosamide alone. Conclusions AOX was found in all the snail intermediate hosts of Schistosoma examined here. AOX was significantly activated in O. hupensis under niclosamide-induced stress, which led to a reduction in oxidative stress in the snail. The inhibition of AOX activity in snails can dramatically enhance the molluscicidal effect of niclosamide. A potential target for the development of an environmentally safe snail control method, which acts by inhibiting the activity of AOX, was identified in this study. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05227-5.
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Affiliation(s)
- Ni Jiang
- Department of Parasitology, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei, China.,Joint Inspection Center of Precision Medicine, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi, China
| | - Shi-Zhu Li
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, National Center for Tropical Diseases Research, WHO Collaborating Center for Tropical Diseases, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, China.
| | - Yang-Wen-Qing Zhang
- Department of Parasitology, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei, China
| | - Mohamed R Habib
- Medical Malacology Department, Theodor Bilharz Research Institute, Giza, Egypt
| | - Tao Xiong
- Department of Microbiology, School of Medical Sciences, Hunan University of Chinese Medicine, Changsha, Hunan, China
| | - Sha Xu
- Department of Parasitology, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei, China
| | - Huifen Dong
- Department of Parasitology, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei, China
| | - Qin-Ping Zhao
- Department of Parasitology, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei, China.
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Mendoza H, Culver CD, Lamb EA, Schroeder LA, Khanal S, Müller C, Schirawski J, Perlin MH. Identification and Functional Characterization of a Putative Alternative Oxidase (Aox) in Sporisorium reilianum f. sp. zeae. J Fungi (Basel) 2022; 8:148. [PMID: 35205901 PMCID: PMC8877474 DOI: 10.3390/jof8020148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/26/2022] [Accepted: 01/28/2022] [Indexed: 12/04/2022] Open
Abstract
The mitochondrial electron transport chain consists of the classical protein complexes (I–IV) that facilitate the flow of electrons and coupled oxidative phosphorylation to produce metabolic energy. The canonical route of electron transport may diverge by the presence of alternative components to the electron transport chain. The following study comprises the bioinformatic identification and functional characterization of a putative alternative oxidase in the smut fungus Sporisorium reilianum f. sp. zeae. This alternative respiratory component has been previously identified in other eukaryotes and is essential for alternative respiration as a response to environmental and chemical stressors, as well as for developmental transitionaoxs during the life cycle of an organism. A growth inhibition assay, using specific mitochondrial inhibitors, functionally confirmed the presence of an antimycin-resistant/salicylhydroxamic acid (SHAM)-sensitive alternative oxidase in the respirasome of S. reilianum. Gene disruption experiments revealed that this enzyme is involved in the pathogenic stage of the fungus, with its absence effectively reducing overall disease incidence in infected maize plants. Furthermore, gene expression analysis revealed that alternative oxidase plays a prominent role in the teliospore developmental stage, in agreement with favoring alternative respiration during quiescent stages of an organism’s life cycle.
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7
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Hou L, Zhao M, Huang C, He Q, Zhang L, Zhang J. Alternative oxidase gene induced by nitric oxide is involved in the regulation of ROS and enhances the resistance of Pleurotus ostreatus to heat stress. Microb Cell Fact 2021; 20:137. [PMID: 34281563 PMCID: PMC8287771 DOI: 10.1186/s12934-021-01626-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 07/04/2021] [Indexed: 12/13/2022] Open
Abstract
Background In China, during the cultivation process of Pleurotus ostreatus, the yield and quality of fruiting bodies are easily affected by high temperatures in summer. Nitric oxide (NO) plays an important regulatory role in the response to abiotic stress, and previous studies have found that NO can induce alternative oxidase (aox) experssion in response to heat stress (HS) by regulating aconitase. However, the regulatory pathway of NO is complex, and the function and regulation of the aox gene in the response to HS remain unclear. Results In this study, we found that NO affected nicotinamide adenine dinucleotide (NADH) and adenosine triphosphate (ATP) levels, reduced hydrogen peroxide (H2O2) and superoxide anion (O2−) contents, and slowed O2− production. Further RNA-Seq results showed that NO regulated the oxidation-reduction process and oxidoreductase activity, affected the cellular respiration pathway and activated aox gene expression. The function of aox was determined by constructing overexpression (OE) and RNA interference (RNAi) strains. The results showed that the OE-aox strains exhibited obviously improved growth recovery after exposure to HS. During exposure to HS, the OE-aox strains exhibited reduced levels of NADH, the product of the tricarboxylic acid (TCA) cycle, and decreased synthesis of ATP, which reduced the production and accumulation of reactive oxygen species (ROS), whereas the RNAi-aox strains exhibited the opposite result. In addition, aox mediated the expression of antioxidant enzyme genes in the mycelia of P. ostreatus under HS through the retrograde signaling pathway. Conclusions This study shows that the expression of the aox gene in P. ostreatus mycelia can be induced by NO under HS, that it regulates the TCA cycle and cell respiration to reduce the production of ROS, and that it can mediate the retrograde signaling pathway involved in the mycelial response to HS. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s12934-021-01626-y.
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Affiliation(s)
- Ludan Hou
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, 10081, Beijing, China.,Key Laboratory of Microbial Resources, Ministry of Agriculture and Rural Affairs, 10081, Beijing, China
| | - Mengran Zhao
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, 10081, Beijing, China.,Key Laboratory of Microbial Resources, Ministry of Agriculture and Rural Affairs, 10081, Beijing, China
| | - Chenyang Huang
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, 10081, Beijing, China.,Key Laboratory of Microbial Resources, Ministry of Agriculture and Rural Affairs, 10081, Beijing, China
| | - Qi He
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, 10081, Beijing, China.,Key Laboratory of Microbial Resources, Ministry of Agriculture and Rural Affairs, 10081, Beijing, China.,Jilin Agricultural University, 130118, Jilin, China
| | - Lijiao Zhang
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, 10081, Beijing, China.,Key Laboratory of Microbial Resources, Ministry of Agriculture and Rural Affairs, 10081, Beijing, China
| | - Jinxia Zhang
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, 10081, Beijing, China. .,Key Laboratory of Microbial Resources, Ministry of Agriculture and Rural Affairs, 10081, Beijing, China.
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8
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Black B, Lee C, Horianopoulos LC, Jung WH, Kronstad JW. Respiring to infect: Emerging links between mitochondria, the electron transport chain, and fungal pathogenesis. PLoS Pathog 2021; 17:e1009661. [PMID: 34237096 PMCID: PMC8266039 DOI: 10.1371/journal.ppat.1009661] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- Braydon Black
- Michael Smith Laboratories, Department of Microbiology & Immunology, University of British Columbia, Vancouver, Canada
| | - Christopher Lee
- Michael Smith Laboratories, Department of Microbiology & Immunology, University of British Columbia, Vancouver, Canada
| | - Linda C. Horianopoulos
- Michael Smith Laboratories, Department of Microbiology & Immunology, University of British Columbia, Vancouver, Canada
| | - Won Hee Jung
- Department of Systems Biotechnology, Chung-Ang University, Anseong, Republic of Korea
| | - James W. Kronstad
- Michael Smith Laboratories, Department of Microbiology & Immunology, University of British Columbia, Vancouver, Canada
- * E-mail:
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Barsottini MRO, Copsey A, Young L, Baroni RM, Cordeiro AT, Pereira GAG, Moore AL. Biochemical characterization and inhibition of the alternative oxidase enzyme from the fungal phytopathogen Moniliophthora perniciosa. Commun Biol 2020; 3:263. [PMID: 32451394 PMCID: PMC7248098 DOI: 10.1038/s42003-020-0981-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 04/30/2020] [Indexed: 01/27/2023] Open
Abstract
Moniliophthora perniciosa is a fungal pathogen and causal agent of the witches' broom disease of cocoa, a threat to the chocolate industry and to the economic and social security in cocoa-planting countries. The membrane-bound enzyme alternative oxidase (MpAOX) is crucial for pathogen survival; however a lack of information on the biochemical properties of MpAOX hinders the development of novel fungicides. In this study, we purified and characterised recombinant MpAOX in dose-response assays with activators and inhibitors, followed by a kinetic characterization both in an aqueous environment and in physiologically-relevant proteoliposomes. We present structure-activity relationships of AOX inhibitors such as colletochlorin B and analogues which, aided by an MpAOX structural model, indicates key residues for protein-inhibitor interaction. We also discuss the importance of the correct hydrophobic environment for MpAOX enzymatic activity. We envisage that such results will guide the future development of AOX-targeting antifungal agents against M. perniciosa, an important outcome for the chocolate industry.
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Affiliation(s)
- Mario R O Barsottini
- Genomics and bioEnergy Laboratory, Institute of Biology, University of Campinas, Campinas, Brazil.,Biochemistry & Biomedicine, School of Life Sciences, University of Sussex, Brighton, BN1 9QG, UK
| | - Alice Copsey
- Biochemistry & Biomedicine, School of Life Sciences, University of Sussex, Brighton, BN1 9QG, UK
| | - Luke Young
- Biochemistry & Biomedicine, School of Life Sciences, University of Sussex, Brighton, BN1 9QG, UK
| | - Renata M Baroni
- Genomics and bioEnergy Laboratory, Institute of Biology, University of Campinas, Campinas, Brazil
| | - Artur T Cordeiro
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
| | - Gonçalo A G Pereira
- Genomics and bioEnergy Laboratory, Institute of Biology, University of Campinas, Campinas, Brazil.
| | - Anthony L Moore
- Biochemistry & Biomedicine, School of Life Sciences, University of Sussex, Brighton, BN1 9QG, UK.
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10
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Caldara M, Marmiroli N. Known Antimicrobials Versus Nortriptyline in Candida albicans: Repositioning an Old Drug for New Targets. Microorganisms 2020; 8:microorganisms8050742. [PMID: 32429222 PMCID: PMC7284794 DOI: 10.3390/microorganisms8050742] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 05/05/2020] [Accepted: 05/12/2020] [Indexed: 02/07/2023] Open
Abstract
Candida albicans has the capacity to develop resistance to commonly used antimicrobials, and to solve this problem, drug repositioning and new drug combinations are being studied. Nortriptyline, a tricyclic antidepressant, was shown to have the capacity to inhibit biofilm and hyphae formation, along with the ability to efficiently kill cells in a mature biofilm. To use nortriptyline as a new antimicrobial, or in combination with known drugs to increase their actions, it is important to characterize in more detail the effects of this drug on the target species. In this study, the Candida albicans GRACE™ collection and a Haplo insufficiency profiling were employed to identify the potential targets of nortriptyline, and to classify, in a parallel screening with amphotericin B, caspofungin, and fluconazole, general multi-drug resistance genes. The results identified mutants that, during biofilm formation and upon treatment of a mature biofilm, are sensitive or tolerant to nortriptyline, or to general drug treatments. Gene ontology analysis recognized the categories of ribosome biogenesis and spliceosome as enriched upon treatment with the tricyclic antidepressant, while mutants in oxidative stress response and general stress response were commonly retrieved upon treatment with any other drug. The data presented suggest that nortriptyline can be considered a “new” antimicrobial drug with large potential for application to in vivo infection models.
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Affiliation(s)
- Marina Caldara
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43124 Parma, Italy;
- Correspondence: ; Tel.: +39-0521-905658
| | - Nelson Marmiroli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43124 Parma, Italy;
- Interdepartmental Center SITEIA.PARMA, University of Parma, Parco Area delle Scienze 181/A, 43124 Parma, Italy
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11
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Costa PC, Barsottini MR, Vieira ML, Pires BA, Evangelista JS, Zeri AC, Nascimento AF, Silva JS, Carazzolle MF, Pereira GA, Sforça ML, Miranda PC, Rocco SA. N-Phenylbenzamide derivatives as alternative oxidase inhibitors: Synthesis, molecular properties, 1H-STD NMR, and QSAR. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2020.127903] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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12
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Bosnjak N, Smith KM, Asaria I, Lahola-Chomiak A, Kishore N, Todd AT, Freitag M, Nargang FE. Involvement of a G Protein Regulatory Circuit in Alternative Oxidase Production in Neurospora crassa. G3 (Bethesda) 2019; 9:3453-3465. [PMID: 31444295 PMCID: PMC6778808 DOI: 10.1534/g3.119.400522] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 08/19/2019] [Indexed: 12/12/2022]
Abstract
The Neurospora crassa nuclear aod-1 gene encodes an alternative oxidase that functions in mitochondria. The enzyme provides a branch from the standard electron transport chain by transferring electrons directly from ubiquinol to oxygen. In standard laboratory strains, aod-1 is transcribed at very low levels under normal growth conditions. However, if the standard electron transport chain is disrupted, aod-1 mRNA expression is induced and the AOD1 protein is produced. We previously identified a strain of N. crassa, that produces high levels of aod-1 transcript under non-inducing conditions. Here we have crossed this strain to a standard lab strain and determined the genomic sequences of the parents and several progeny. Analysis of the sequence data and the levels of aod-1 mRNA in uninduced cultures revealed that a frameshift mutation in the flbA gene results in the high uninduced expression of aod-1 The flbA gene encodes a regulator of G protein signaling that decreases the activity of the Gα subunit of heterotrimeric G proteins. Our data suggest that strains with a functional flbA gene prevent uninduced expression of aod-1 by inactivating a G protein signaling pathway, and that this pathway is activated in cells grown under conditions that induce aod-1 Induced cells with a deletion of the gene encoding the Gα protein still have a partial increase in aod-1 mRNA levels, suggesting a second pathway for inducing transcription of the gene in N. crassa We also present evidence that a translational control mechanism prevents production of AOD1 protein in uninduced cultures.
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Affiliation(s)
- Natasa Bosnjak
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E9 and
| | - Kristina M Smith
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331-4003
| | - Iman Asaria
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E9 and
| | - Adrian Lahola-Chomiak
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E9 and
| | - Nishka Kishore
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E9 and
| | - Andrea T Todd
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E9 and
| | - Michael Freitag
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331-4003
| | - Frank E Nargang
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E9 and
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13
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Duvenage L, Munro CA, Gourlay CW. The potential of respiration inhibition as a new approach to combat human fungal pathogens. Curr Genet 2019; 65:1347-53. [PMID: 31172256 DOI: 10.1007/s00294-019-01001-w] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 05/24/2019] [Accepted: 05/27/2019] [Indexed: 02/06/2023]
Abstract
The respiratory chain has been proposed as an attractive target for the development of new therapies to tackle human fungal pathogens. This arises from the presence of fungal-specific electron transport chain components and links between respiration and the control of virulence traits in several pathogenic species. However, as the physiological roles of mitochondria remain largely undetermined with respect to pathogenesis, its value as a potential new drug target remains to be determined. The use of respiration inhibitors as fungicides is well developed but has been hampered by the emergence of rapid resistance to current inhibitors. In addition, recent data suggest that adaptation of the human fungal pathogen, Candida albicans, to respiration inhibitors can enhance virulence traits such as yeast-to-hypha transition and cell wall organisation. We conclude that although respiration holds promise as a target for the development of new therapies to treat human fungal infections, we require a more detailed understanding of the role that mitochondria play in stress adaption and virulence.
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Barsottini MR, Pires BA, Vieira ML, Pereira JG, Costa PC, Sanitá J, Coradini A, Mello F, Marschalk C, Silva EM, Paschoal D, Figueira A, Rodrigues FH, Cordeiro AT, Miranda PC, Oliveira PS, Sforça ML, Carazzolle MF, Rocco SA, Pereira GA. Synthesis and testing of novel alternative oxidase (AOX) inhibitors with antifungal activity against Moniliophthora perniciosa (Stahel), the causal agent of witches' broom disease of cocoa, and other phytopathogens. Pest Manag Sci 2019; 75:1295-1303. [PMID: 30350447 DOI: 10.1002/ps.5243] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 09/18/2018] [Accepted: 10/16/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Moniliophthora perniciosa (Stahel) Aime & Phillips-Mora is the causal agent of witches' broom disease (WBD) of cocoa (Theobroma cacao L.) and a threat to the chocolate industry. The membrane-bound enzyme alternative oxidase (AOX) is critical for M. perniciosa virulence and resistance to fungicides, which has also been observed in other phytopathogens. Notably AOX is an escape mechanism from strobilurins and other respiration inhibitors, making AOX a promising target for controlling WBD and other fungal diseases. RESULTS We present the first study aimed at developing novel fungal AOX inhibitors. N-Phenylbenzamide (NPD) derivatives were screened in the model yeast Pichia pastoris through oxygen consumption and growth measurements. The most promising AOX inhibitor (NPD 7j-41) was further characterized and displayed better activity than the classical AOX inhibitor SHAM in vitro against filamentous fugal phytopathogens, such as M. perniciosa, Sclerotinia sclerotiorum and Venturia pirina. We demonstrate that 7j-41 inhibits M. perniciosa spore germination and prevents WBD symptom appearance in infected plants. Finally, a structural model of P. pastoris AOX was created and used in ligand structure-activity relationships analyses. CONCLUSION We present novel fungal AOX inhibitors with antifungal activity against relevant phytopathogens. We envisage the development of novel antifungal agents to secure food production. © 2018 Society of Chemical Industry.
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Affiliation(s)
- Mario Ro Barsottini
- Department of Genetics, Evolution, Microbiology and Imunology, Genomics and bioEnergy Laboratory, Institute of Biology, State University of Campinas, Campinas, Brazil
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
| | - Bárbara A Pires
- Department of Genetics, Evolution, Microbiology and Imunology, Genomics and bioEnergy Laboratory, Institute of Biology, State University of Campinas, Campinas, Brazil
| | - Maria L Vieira
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
| | - José Gc Pereira
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
| | - Paulo Cs Costa
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
- Department of Organic Chemistry, Institute of Chemistry, State University of Campinas, Campinas, Brazil
| | - Jaqueline Sanitá
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
| | - Alessandro Coradini
- Department of Genetics, Evolution, Microbiology and Imunology, Genomics and bioEnergy Laboratory, Institute of Biology, State University of Campinas, Campinas, Brazil
| | - Fellipe Mello
- Department of Genetics, Evolution, Microbiology and Imunology, Genomics and bioEnergy Laboratory, Institute of Biology, State University of Campinas, Campinas, Brazil
| | - Cidnei Marschalk
- Department of Genetics, Evolution, Microbiology and Imunology, Genomics and bioEnergy Laboratory, Institute of Biology, State University of Campinas, Campinas, Brazil
| | - Eder M Silva
- Center for Nuclear Energy in Agriculture, University of Sao Paulo, Piracicaba, Brazil
| | - Daniele Paschoal
- Center for Nuclear Energy in Agriculture, University of Sao Paulo, Piracicaba, Brazil
| | - Antonio Figueira
- Center for Nuclear Energy in Agriculture, University of Sao Paulo, Piracicaba, Brazil
| | - Fábio Hs Rodrigues
- School of Life Sciences, University of Warwick - Gibbet Hill Campus, Coventry, United Kingdom
| | - Artur T Cordeiro
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
| | - Paulo Cml Miranda
- Department of Organic Chemistry, Institute of Chemistry, State University of Campinas, Campinas, Brazil
| | - Paulo Sl Oliveira
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
| | - Maurício L Sforça
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
| | - Marcelo F Carazzolle
- Department of Genetics, Evolution, Microbiology and Imunology, Genomics and bioEnergy Laboratory, Institute of Biology, State University of Campinas, Campinas, Brazil
| | - Silvana A Rocco
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Brazil
| | - Gonçalo Ag Pereira
- Department of Genetics, Evolution, Microbiology and Imunology, Genomics and bioEnergy Laboratory, Institute of Biology, State University of Campinas, Campinas, Brazil
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15
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Luévano-Martínez LA, Caldeira da Silva CC, Nicastro GG, Schumacher RI, Kowaltowski AJ, Gomes SL. Mitochondrial alternative oxidase is determinant for growth and sporulation in the early diverging fungus Blastocladiella emersonii. Fungal Biol 2018; 123:59-65. [PMID: 30654958 DOI: 10.1016/j.funbio.2018.11.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 10/31/2018] [Accepted: 11/08/2018] [Indexed: 10/27/2022]
Abstract
Blastocladiella emersonii is an early diverging fungus of the phylum Blastocladiomycota. During the life cycle of the fungus, mitochondrial morphology changes significantly, from a fragmented form in sessile vegetative cells to a fused network in motile zoospores. In this study, we visualize these morphological changes using a mitochondrial fluorescent probe and show that the respiratory capacity in zoospores is much higher than in vegetative cells, suggesting that mitochondrial morphology could be related to the differences in oxygen consumption. While studying the respiratory chain of the fungus, we observed an antimycin A and cyanide-insensitive, salicylhydroxamic (SHAM)-sensitive respiratory activity, indicative of a mitochondrial alternative oxidase (AOX) activity. The presence of AOX was confirmed by the finding of a B. emersonii cDNA encoding a putative AOX, and by detection of AOX protein in immunoblots. Inhibition of AOX activity by SHAM was found to significantly alter the capacity of the fungus to grow and sporulate, indicating that AOX participates in life cycle control in B. emersonii.
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Affiliation(s)
- Luis Alberto Luévano-Martínez
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, São Paulo, Brazil; Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | | | - Gianlucca G Nicastro
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, São Paulo, Brazil
| | - Robert I Schumacher
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, São Paulo, Brazil
| | - Alicia J Kowaltowski
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, São Paulo, Brazil
| | - Suely L Gomes
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, São Paulo, Brazil.
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16
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Rocha MC, de Godoy KF, Bannitz-Fernandes R, Fabri JHTM, Barbosa MMF, de Castro PA, Almeida F, Goldman GH, da Cunha AF, Netto LES, de Oliveira MA, Malavazi I. Analyses of the three 1-Cys Peroxiredoxins from Aspergillus fumigatus reveal that cytosolic Prx1 is central to H 2O 2 metabolism and virulence. Sci Rep 2018; 8:12314. [PMID: 30120327 DOI: 10.1038/s41598-018-30108-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 07/24/2018] [Indexed: 12/17/2022] Open
Abstract
Standing among the front defense strategies against pathogens, host phagocytic cells release various oxidants. Therefore, pathogens have to cope with stressful conditions at the site of infection. Peroxiredoxins (Prx) are highly reactive and abundant peroxidases that can support virulence and persistence of pathogens in distinct hosts. Here, we revealed that the opportunistic human pathogen A. fumigatus presents three 1-Cys Prx (Prx6 subfamily), which is unprecedented. We showed that PrxB and PrxC were in mitochondria, while Prx1 was in cytosol. As observed for other Prxs, recombinant Prx1 and PrxC decomposed H2O2 at elevated velocities (rate constants in the 107 M−1s−1 range). Deletion mutants for each Prx displayed higher sensitivity to oxidative challenge in comparison with the wild-type strain. Additionally, cytosolic Prx1 was important for A. fumigatus survival upon electron transport dysfunction. Expression of Prxs was dependent on the SakAHOG1 MAP kinase and the Yap1YAP1 transcription factor, a global regulator of the oxidative stress response in fungi. Finally, cytosolic Prx1 played a major role in pathogenicity, since it is required for full virulence, using a neutropenic mouse infection model. Our data indicate that the three 1-Cys Prxs act together to maintain the redox balance of A. fumigatus.
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17
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Lu Z, Jia X, Chen Y, Han X, Chen F, Tian S, Su X, Li Z, Zhao J, Zhang X, Hu M, Huang L, Han L. Identification and Characterization of Key Charged Residues in the Cofilin Protein Involved in Azole Susceptibility, Apoptosis, and Virulence of Aspergillus fumigatus. Antimicrob Agents Chemother 2018; 62:e01659-17. [PMID: 29483117 DOI: 10.1128/AAC.01659-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 02/10/2018] [Indexed: 12/28/2022] Open
Abstract
Through some specific amino acid residues, cofilin, a ubiquitous actin depolymerization factor, can significantly affect mitochondrial function related to drug resistance and apoptosis in Saccharomyces cerevisiae; however, this modulation in a major fungal pathogen, Aspergillus fumigatus, was still unclear. Hereby, it was found, first, that mutations on several charged residues in cofilin to alanine, D19A-R21A, E48A, and K36A, increased the formation of reactive oxygen species and induced apoptosis along with typical hallmarks, including mitochondrial membrane potential depolarization, cytochrome c release, upregulation of metacaspases, and DNA cleavage, in A. fumigatus Two of these mutations (D19A-R21A and K36A) increased acetyl coenzyme A and ATP concentrations by triggering fatty acid β-oxidation. The upregulated acetyl coenzyme A affected the ergosterol biosynthetic pathway, leading to overexpression of cyp51A and -B, while excess ATP fueled ATP-binding cassette transporters. Besides, both of these mutations reduced the susceptibility of A. fumigatus to azole drugs and enhanced the virulence of A. fumigatus in a Galleria mellonella infection model. Taken together, novel and key charged residues in cofilin were identified to be essential modules regulating the mitochondrial function involved in azole susceptibility, apoptosis, and virulence of A. fumigatus.
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18
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Abstract
The balance between reactive oxygen species and reactive nitrogen species production by the host and stress response by fungi is a key axis of the host-pathogen interaction. This review will describe emerging themes in fungal pathogenesis underpinning this axis.
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Affiliation(s)
- Adilia Warris
- Medical Research Centre for Medical Mycology, Aberdeen Fungal Group, Institute of Medical Sciences, University of Aberdeen, UK
| | - Elizabeth R Ballou
- Institute for Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
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19
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Castilho DG, Navarro MV, Chaves AFA, Xander P, Batista WL. Recovery of the Paracoccidioides brasiliensis virulence after animal passage promotes changes in the antioxidant repertoire of the fungus. FEMS Yeast Res 2018; 18:4835518. [DOI: 10.1093/femsyr/foy007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 01/31/2018] [Indexed: 01/20/2023] Open
Affiliation(s)
- Daniele G Castilho
- Department of Microbiology, Immunology and Parasitology, Universidade Federal de São Paulo (UNIFESP), São Paulo 04023-062, Brazil
| | - Marina V Navarro
- Department of Microbiology, Immunology and Parasitology, Universidade Federal de São Paulo (UNIFESP), São Paulo 04023-062, Brazil
| | - Alison F A Chaves
- Department of Microbiology, Immunology and Parasitology, Universidade Federal de São Paulo (UNIFESP), São Paulo 04023-062, Brazil
| | - Patricia Xander
- Department of Pharmaceutical Sciences, Instituto de Ciências Ambientais, Químicas e Farmacêuticas (ICAQF), Universidade Federal de São Paulo (UNIFESP), Campus Diadema, Rua São Nicolau, 210, Diadema 09913-030, Brazil
| | - Wagner L Batista
- Department of Microbiology, Immunology and Parasitology, Universidade Federal de São Paulo (UNIFESP), São Paulo 04023-062, Brazil
- Department of Pharmaceutical Sciences, Instituto de Ciências Ambientais, Químicas e Farmacêuticas (ICAQF), Universidade Federal de São Paulo (UNIFESP), Campus Diadema, Rua São Nicolau, 210, Diadema 09913-030, Brazil
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20
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Manfiolli AO, de Castro PA, dos Reis TF, Dolan S, Doyle S, Jones G, Riaño Pachón DM, Ulaş M, Noble LM, Mattern DJ, Brakhage AA, Valiante V, Silva-Rocha R, Bayram O, Goldman GH. Aspergillus fumigatusprotein phosphatase PpzA is involved in iron assimilation, secondary metabolite production, and virulence. Cell Microbiol 2017; 19. [DOI: 10.1111/cmi.12770] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 06/28/2017] [Accepted: 07/14/2017] [Indexed: 01/19/2023]
Affiliation(s)
| | - Patrícia Alves de Castro
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto; Universidade de São Paulo; Ribeirão Preto Brazil
| | - Thaila Fernanda dos Reis
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto; Universidade de São Paulo; Ribeirão Preto Brazil
| | - Stephen Dolan
- Department of Biology; Maynooth University; Maynooth Co. Kildare Ireland
| | - Sean Doyle
- Department of Biology; Maynooth University; Maynooth Co. Kildare Ireland
| | - Gary Jones
- Department of Biology; Maynooth University; Maynooth Co. Kildare Ireland
| | - Diego M. Riaño Pachón
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE); Centro Nacional de Pesquisa em Energia e Materiais (CNPEM); Campinas São Paulo Brazil
| | - Mevlüt Ulaş
- Department of Biology; Maynooth University; Maynooth Co. Kildare Ireland
| | | | - Derek J. Mattern
- Department of Molecular and Applied Microbiology; Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute; Jena Germany
- University of Jena; Jena Germany
| | - Axel A. Brakhage
- Department of Molecular and Applied Microbiology; Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute; Jena Germany
- University of Jena; Jena Germany
| | - Vito Valiante
- Leibniz Research Group-Biobricks of Microbial Natural Product Syntheses; Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute; Jena Germany
| | - Rafael Silva-Rocha
- Faculdade de Medicina de Ribeirão Preto; Universidade de São Paulo; Ribeirão Preto Brazil
| | - Ozgur Bayram
- Department of Biology; Maynooth University; Maynooth Co. Kildare Ireland
| | - Gustavo H. Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto; Universidade de São Paulo; Ribeirão Preto Brazil
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21
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Shao Y, Li Q, Zhou Y, Chen F. Effects of an alternative oxidase gene on conidia viability under external stresses in Monascus ruber M7. J Basic Microbiol 2017; 57:413-418. [PMID: 28225559 DOI: 10.1002/jobm.201600707] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 12/21/2016] [Accepted: 12/29/2016] [Indexed: 11/06/2022]
Abstract
Monascus species can produce natural edible pigments and many other bioactive metabolites. In this study, mraox gene (Monascus ruber alternative oxidase) was isolated, sequenced, and replaced in order to investigate the function in resistance of conidia to stressful conditions. The derived protein of the mraox gene consisted of 350 amino acids with a conserved ferritin-like diiron-binding domain at the C-terminus, sharing a high homolog with alternative oxidase proteins in other filamentous fungi. Deletion of mraox gene repressed the conidia germination rate (CGR) when conidia were exposed to H2 O2 , high temperature (40 and 50 °C) and alkerline buffer (pH8.0), but CGR of mraox-deleted strain was not decreased when the conidia were treated with NaCl, acid buffer (citric acid-dibasic sodium phosphate buffer, pH3) compared to that of the wild-type strain, suggesting that mraox gene is partially responsible for the resistance of conidia to stressful conditions in M. ruber.
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Affiliation(s)
- Yanchun Shao
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei Province, PR China
| | - Qi Li
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei Province, PR China
| | - Youxiang Zhou
- Institute of Quality Standard and Testing Technology for Agro-Products, Hubei Academy of Agricultural Sciences, Hongshan District, Wuhany, Hubei Province, PR China
| | - Fusheng Chen
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei Province, PR China.,Key Laboratory of Environment Correlative Dietology, Ministry of Education, Huazhong Agricultural University, Wuhan, Hubei Province, PR China
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22
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Schinagl CW, Vrabl P, Burgstaller W. Adapting High-Resolution Respirometry to Glucose-Limited Steady State Mycelium of the Filamentous Fungus Penicillium ochrochloron: Method Development and Standardisation. PLoS One 2016; 11:e0146878. [PMID: 26771937 PMCID: PMC4714917 DOI: 10.1371/journal.pone.0146878] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 12/24/2015] [Indexed: 11/29/2022] Open
Abstract
Fungal electron transport systems (ETS) are branched, involving alternative NADH dehydrogenases and an alternative terminal oxidase. These alternative respiratory enzymes were reported to play a role in pathogenesis, production of antibiotics and excretion of organic acids. The activity of these alternative respiratory enzymes strongly depends on environmental conditions. Functional analysis of fungal ETS under highly standardised conditions for cultivation, sample processing and respirometric assay are still lacking. We developed a highly standardised protocol to explore in vivo the ETS—and in particular the alternative oxidase—in Penicillium ochrochloron. This included cultivation in glucose-limited chemostat (to achieve a defined and reproducible physiological state), direct transfer without any manipulation of a broth sample to the respirometer (to maintain the physiological state in the respirometer as close as possible to that in the chemostat), and high-resolution respirometry (small sample volume and high measuring accuracy). This protocol was aimed at avoiding any changes in the physiological phenotype due to the high phenotypic plasticity of filamentous fungi. A stable oxygen consumption (< 5% change in 20 minutes) was only possible with glucose limited chemostat mycelium and a direct transfer of a broth sample into the respirometer. Steady state respiration was 29% below its maximum respiratory capacity. Additionally to a rotenone-sensitive complex I and most probably a functioning complex III, the ETS of P. ochrochloron also contained a cyanide-sensitive terminal oxidase (complex IV). Activity of alternative oxidase was present constitutively. The degree of inhibition strongly depended on the sequence of inhibitor addition. This suggested, as postulated for plants, that the alternative terminal oxidase was in dynamic equilibrium with complex IV—independent of the rate of electron flux. This means that the onset of activity does not depend on a complete saturation or inhibition of the cytochrome pathway.
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Affiliation(s)
| | - Pamela Vrabl
- University of Innsbruck, Institute of Microbiology, Innsbruck, Austria
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23
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Chen F, Everhart SE, Bryson PK, Luo C, Song X, Liu X, Schnabel G. Fungicide-induced transposon movement in Monilinia fructicola. Fungal Genet Biol 2015; 85:38-44. [PMID: 26537535 DOI: 10.1016/j.fgb.2015.10.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 10/10/2015] [Accepted: 10/29/2015] [Indexed: 11/22/2022]
Abstract
Repeated applications of fungicides with a single mode of action are believed to select for pre-existing resistant strains in a pathogen population, while the impact of sub-lethal doses of such fungicides on sensitive members of the population is unknown. In this study, in vitro evidence is presented that continuous exposure of Monilinia fructicola mycelium to some fungicides can induce genetic change in form of transposon transposition. Three fungicide-sensitive M. fructicola isolates were exposed in 12 weekly transfers of mycelia to a dose gradient of demethylation inhibitor fungicide (DMI) SYP-Z048 and quinone outside inhibitor fungicide (QoI) azoxystrobin in solo or mixture treatments. Evidence of mutagenesis was assessed by monitoring Mftc1, a multicopy transposable element of M. fructicola, by PCR and Southern blot analysis. Movement of Mftc1 was observed following azoxystrobin and azoxystrobin plus SYP-Z048 treatments in two of the three isolates, but not in the non-fungicide-treated controls. Interestingly, the upstream promoter region of MfCYP51 was a prime target for Mftc1 transposition in these isolates. Transposition of Mftc1 was verified by Southern blot in two of three isolates from another, similar experiment following prolonged, sublethal azoxystrobin exposure, although in these isolates movement of Mftc1 in the upstream MfCYP51 promoter region was not observed. More research is warranted to determine whether fungicide-induced mutagenesis may also happen under field conditions.
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24
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Hillmann F, Shekhova E, Kniemeyer O. Insights into the cellular responses to hypoxia in filamentous fungi. Curr Genet 2015; 61:441-55. [PMID: 25911540 DOI: 10.1007/s00294-015-0487-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 03/31/2015] [Accepted: 04/02/2015] [Indexed: 01/06/2023]
Abstract
Most eukaryotes require molecular oxygen for growth. In general, oxygen is the terminal electron acceptor of the respiratory chain and represents an important substrate for the biosynthesis of cellular compounds. However, in their natural environment, such as soil, and also during the infection, filamentous fungi are confronted with low levels of atmospheric oxygen. Transcriptome and proteome studies on the hypoxic response of filamentous fungi revealed significant alteration of the gene expression and protein synthesis upon hypoxia. These analyses discovered not only common but also species-specific responses to hypoxia with regard to NAD(+) regeneration systems and other metabolic pathways. A surprising outcome was that the induction of oxidative and nitrosative stress defenses during oxygen limitation represents a general trait of adaptation to hypoxia in many fungi. The interplay of these different stress responses is poorly understood, but recent studies have shown that adaptation to hypoxia contributes to virulence of pathogenic fungi. In this review, results on metabolic changes of filamentous fungi during adaptation to hypoxia are summarized and discussed.
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25
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Hernández O, Araque P, Tamayo D, Restrepo A, Herrera S, Mcewen JG, Pelaez C, Almeida AJ. Alternative oxidase plays an important role in Paracoccidioides brasiliensis cellular homeostasis and morphological transition. Med Mycol 2015; 53:205-14. [DOI: 10.1093/mmy/myu091] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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26
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Voelz K, Johnston SA, Smith LM, Hall RA, Idnurm A, May RC. 'Division of labour' in response to host oxidative burst drives a fatal Cryptococcus gattii outbreak. Nat Commun 2014; 5:5194. [PMID: 25323068 PMCID: PMC4208095 DOI: 10.1038/ncomms6194] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 09/09/2014] [Indexed: 12/03/2022] Open
Abstract
Cryptococcus gattii is an emerging intracellular pathogen and the cause of the largest primary outbreak of a life-threatening fungal disease in a healthy population. Outbreak strains share a unique mitochondrial gene expression profile and an increased ability to tubularize their mitochondria within host macrophages. However, the underlying mechanism that causes this lineage of C. gattii to be virulent in immunocompetent individuals remains unexplained. Here we show that a subpopulation of intracellular C. gattii adopts a tubular mitochondrial morphology in response to host reactive oxygen species. These fungal cells then facilitate the rapid growth of neighbouring C. gattii cells with non-tubular mitochondria, allowing for effective establishment of the pathogen within a macrophage intracellular niche. Thus, host reactive oxygen species, an essential component of the innate immune response, act as major signalling molecules to trigger a ‘division of labour’ in the intracellular fungal population, leading to increased pathogenesis within this outbreak lineage. Outbreak strains of the pathogenic fungus Cryptococcus gattii display an increased ability to form tubular mitochondria. Here, Voelz et al. show that mitochondrial tubularization is induced by host reactive oxygen species within macrophages and facilitates rapid growth of neighbouring fungal cells.
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Affiliation(s)
- Kerstin Voelz
- 1] Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, West Midlands, Birmingham B15 2TT, UK [2] National Institute of Health Research Surgical Reconstruction and Microbiology Research Centre, Queen Elizabeth Hospital Birmingham, Birmingham B15 2TH, UK
| | - Simon A Johnston
- 1] Department of Infection and Immunity, University of Sheffield, Medical School, Beech Hill Road, Sheffield S10 2RX, UK [2] Bateson Centre, Department of Biomedical Sciences, University of Sheffield, Firth Court, Western Bank S10 2TN, UK
| | - Leanne M Smith
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, West Midlands, Birmingham B15 2TT, UK
| | - Rebecca A Hall
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, West Midlands, Birmingham B15 2TT, UK
| | - Alexander Idnurm
- School of Biological Sciences, University of Missouri, Kansas City, Missouri 64110, USA
| | - Robin C May
- 1] Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, West Midlands, Birmingham B15 2TT, UK [2] National Institute of Health Research Surgical Reconstruction and Microbiology Research Centre, Queen Elizabeth Hospital Birmingham, Birmingham B15 2TH, UK
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27
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Klein OI, Isakova EP, Deryabina YI, Kulikova NA, Badun GA, Chernysheva MG, Stepanova EV, Koroleva OV. Humic substances enhance growth and respiration in the basidiomycetes Trametes maxima under carbon limited conditions. J Chem Ecol 2014; 40:643-52. [PMID: 24859517 DOI: 10.1007/s10886-014-0445-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 04/28/2014] [Accepted: 05/01/2014] [Indexed: 10/25/2022]
Abstract
Humic substances (HS) represent the major reservoir of carbon (C) in ecosystems, and their turnover is crucial for understanding the global C cycle. Although basidiomycetes clearly have a role in HS degradation, much less is known about the effect of HS on fungal traits. We studied the alteration of physiological, biochemical, and morphological characteristics of Trametes maxima in the presence of HS. Both complete medium and minimal (C-limited) medium mimicking natural environmental conditions were used. Adding HS led to increased biomass yield, but under C-limited conditions the effect was more apparent. This result indicated that HS were used as an additional substrate and agreed with data showing a greater penetration of tritium-labeled HS into the cell interior under C-limited conditions. Humic substances induced ultra-structural changes in fungal cells, especially under C limitation, including reducing the thicknesses of the hyphal sheath and cell wall. In the minimal medium, cellular respiration increased nearly three-fold under HS application, while the corresponding effect in complete medium was lower. In addition, in the presence of inhibitors, HS stimulated either the cytochrome or the alternative pathway of respiration, depending on presence or absence of glucose in the medium. Our results suggest that, under conditions mimicking the natural environment, HS may play three major roles: as a surplus substrate for fungal growth, as a factor positively affecting cell morphology, and as an activator of physiological respiration.
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Bajaj I, Veiga T, van Dissel D, Pronk JT, Daran JM. Functional characterization of a Penicillium chrysogenum mutanase gene induced upon co-cultivation with Bacillus subtilis. BMC Microbiol 2014; 14:114. [PMID: 24884713 PMCID: PMC4077275 DOI: 10.1186/1471-2180-14-114] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 04/17/2014] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Microbial gene expression is strongly influenced by environmental growth conditions. Comparison of gene expression under different conditions is frequently used for functional analysis and to unravel regulatory networks, however, gene expression responses to co-cultivation with other microorganisms, a common occurrence in nature, is rarely studied under laboratory conditions. To explore cellular responses of the antibiotic-producing fungus Penicillium chrysogenum to prokaryotes, the present study investigates its transcriptional responses during co-cultivation with Bacillus subtilis. RESULTS Steady-state glucose-limited chemostats of P. chrysogenum grown under penillicin-non-producing conditions were inoculated with B. subtilis. Physiological and transcriptional responses of P. chrysogenum in the resulting mixed culture were monitored over 72 h. Under these conditions, B. subtilis outcompeted P. chrysogenum, as reflected by a three-fold increase of the B. subtilis population size and a two-fold reduction of the P. chrysogenum biomass concentration. Genes involved in the penicillin pathway and in synthesis of the penicillin precursors and side-chain were unresponsive to the presence of B. subtilis. Moreover, Penicillium polyketide synthase and nonribosomal peptide synthase genes were either not expressed or down-regulated. Among the highly responsive genes, two putative α-1,3 endoglucanase (mutanase) genes viz Pc12g07500 and Pc12g13330 were upregulated by more than 15-fold and 8-fold, respectively. Measurement of enzyme activity in the supernatant of mixed culture confirmed that the co-cultivation with B. subtilis induced mutanase production. Mutanase activity was neither observed in pure cultures of P. chrysogenum or B. subtilis, nor during exposure of P. chrysogenum to B. subtilis culture supernatants or heat-inactivated B. subtilis cells. However, mutanase production was observed in cultures of P. chrysogenum exposed to filter-sterilized supernatants of mixed cultures of P. chrysogenum and B. subtilis. Heterologous expression of Pc12g07500 and Pc12g13330 genes in Saccharomyces cerevisiae confirmed that Pc12g07500 encoded an active α-1,3 endoglucanase. CONCLUSION Time-course transcriptional profiling of P. chrysogenum revealed differentially expressed genes during co-cultivation with B. subtilis. Penicillin production was not induced under these conditions. However, induction of a newly characterized P. chrysogenum gene encoding α-1,3 endoglucanase may enhance the efficacy of fungal antibiotics by degrading bacterial exopolysaccharides.
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Affiliation(s)
- Ishwar Bajaj
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, the Netherlands
- Kluyver Centre for Genomics of Industrial Fermentation, Julianalaan 67, 2628 BC Delft, the Netherlands
| | - Tânia Veiga
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, the Netherlands
- Kluyver Centre for Genomics of Industrial Fermentation, Julianalaan 67, 2628 BC Delft, the Netherlands
| | - Dino van Dissel
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, the Netherlands
- Kluyver Centre for Genomics of Industrial Fermentation, Julianalaan 67, 2628 BC Delft, the Netherlands
| | - Jack T Pronk
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, the Netherlands
- Kluyver Centre for Genomics of Industrial Fermentation, Julianalaan 67, 2628 BC Delft, the Netherlands
| | - Jean-Marc Daran
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, the Netherlands
- Kluyver Centre for Genomics of Industrial Fermentation, Julianalaan 67, 2628 BC Delft, the Netherlands
- Platform for Green Synthetic Biology, P.O. Box 5057, 2600 GA Delft, the Netherlands
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Schumacher J, Simon A, Cohrs KC, Viaud M, Tudzynski P. The transcription factor BcLTF1 regulates virulence and light responses in the necrotrophic plant pathogen Botrytis cinerea. PLoS Genet 2014; 10:e1004040. [PMID: 24415947 DOI: 10.1371/journal.pgen.1004040] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 11/01/2013] [Indexed: 01/16/2023] Open
Abstract
Botrytis cinerea is the causal agent of gray mold diseases in a range of dicotyledonous plant species. The fungus can reproduce asexually by forming macroconidia for dispersal and sclerotia for survival; the latter also participate in sexual reproduction by bearing the apothecia after fertilization by microconidia. Light induces the differentiation of conidia and apothecia, while sclerotia are exclusively formed in the absence of light. The relevance of light for virulence of the fungus is not obvious, but infections are observed under natural illumination as well as in constant darkness. By a random mutagenesis approach, we identified a novel virulence-related gene encoding a GATA transcription factor (BcLTF1 for light-responsive TF1) with characterized homologues in Aspergillus nidulans (NsdD) and Neurospora crassa (SUB-1). By deletion and over-expression of bcltf1, we confirmed the predicted role of the transcription factor in virulence, and discovered furthermore its functions in regulation of light-dependent differentiation, the equilibrium between production and scavenging of reactive oxygen species (ROS), and secondary metabolism. Microarray analyses revealed 293 light-responsive genes, and that the expression levels of the majority of these genes (66%) are modulated by BcLTF1. In addition, the deletion of bcltf1 affects the expression of 1,539 genes irrespective of the light conditions, including the overexpression of known and so far uncharacterized secondary metabolism-related genes. Increased expression of genes encoding alternative respiration enzymes, such as the alternative oxidase (AOX), suggest a mitochondrial dysfunction in the absence of bcltf1. The hypersensitivity of Δbctlf1 mutants to exogenously applied oxidative stress - even in the absence of light - and the restoration of virulence and growth rates in continuous light by antioxidants, indicate that BcLTF1 is required to cope with oxidative stress that is caused either by exposure to light or arising during host infection. Both fungal pathogens and their host plants respond to light, which represents an important environmental cue. Unlike plants using light for energy generation, filamentous fungi use light, or its absence, as a general signal for orientation (night/day, underground/on the surface). Therefore, dependent on the ecological niche of the fungus, light may control the development of reproductive structures (photomorphogenesis), the dispersal of propagules (phototropism of reproductive structures) and the circadian rhythm. As in other organisms, fungi have to protect themselves against the detrimental effects of light, i.e. the damage to macromolecules by emerging singlet oxygen. Adaptive responses are the accumulation of pigments, especially in the reproductive and survival structures such as spores, sclerotia and fruiting bodies. Light is sensed by fungal photoreceptors leading to quick responses on the transcriptional level, and is furthermore considered to result in the accumulation of reactive oxygen species (ROS). In this study, we provide evidence that an unbalanced ROS homoeostasis (generation outweighs detoxification) caused by the deletion of the light-responsive transcription factor BcLTF1 impairs the ability of the necrotrophic pathogen Botrytis cinerea to grow in the presence of additional oxidative stress arising during illumination or during infection of the host.
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Bovier E, Sellem CH, Humbert A, Sainsard-Chanet A. Genetic and functional investigation of Zn(2)Cys(6) transcription factors RSE2 and RSE3 in Podospora anserina. Eukaryot Cell 2014; 13:53-65. [PMID: 24186951 DOI: 10.1128/EC.00172-13] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In Podospora anserina, the two zinc cluster proteins RSE2 and RSE3 are essential for the expression of the gene encoding the alternative oxidase (aox) when the mitochondrial electron transport chain is impaired. In parallel, they activated the expression of gluconeogenic genes encoding phosphoenolpyruvate carboxykinase (pck) and fructose-1,6-biphosphatase (fbp). Orthologues of these transcription factors are present in a wide range of filamentous fungi, and no other role than the regulation of these three genes has been evidenced so far. In order to better understand the function and the organization of RSE2 and RSE3, we conducted a saturated genetic screen based on the constitutive expression of the aox gene. We identified 10 independent mutations in 9 positions in rse2 and 11 mutations in 5 positions in rse3. Deletions were generated at some of these positions and the effects analyzed. This analysis suggests the presence of central regulatory domains and a C-terminal activation domain in both proteins. Microarray analysis revealed 598 genes that were differentially expressed in the strains containing gain- or loss-of-function mutations in rse2 or rse3. It showed that in addition to aox, fbp, and pck, RSE2 and RSE3 regulate the expression of genes encoding the alternative NADH dehydrogenase, a Zn2Cys6 transcription factor, a flavohemoglobin, and various hydrolases. As a complement to expression data, a metabolome profiling approach revealed that both an rse2 gain-of-function mutation and growth on antimycin result in similar metabolic alterations in amino acids, fatty acids, and α-ketoglutarate pools.
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Thomazella DPT, Teixeira PJPL, Oliveira HC, Saviani EE, Rincones J, Toni IM, Reis O, Garcia O, Meinhardt LW, Salgado I, Pereira GAG. The hemibiotrophic cacao pathogen Moniliophthora perniciosa depends on a mitochondrial alternative oxidase for biotrophic development. New Phytol 2012; 194:1025-1034. [PMID: 22443281 PMCID: PMC3415677 DOI: 10.1111/j.1469-8137.2012.04119.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The tropical pathogen Moniliophthora perniciosa causes witches' broom disease in cacao. As a hemibiotrophic fungus, it initially colonizes the living host tissues (biotrophic phase), and later grows over the dead plant (necrotrophic phase). Little is known about the mechanisms that promote these distinct fungal phases or mediate the transition between them. An alternative oxidase gene (Mp-aox) was identified in the M. perniciosa genome and its expression was analyzed througout the fungal life cycle. In addition, the effects of inhibitors of the cytochrome-dependent respiratory chain (CRC) and alternative oxidase (AOX) were evaluated on the in vitro development of M. perniciosa. Larger numbers of Mp-aox transcripts were observed in the biotrophic hyphae, which accordingly showed elevated sensitivity to AOX inhibitors. More importantly, the inhibition of CRC prevented the transition from the biotrophic to the necrotrophic phase, and the combined use of a CRC and AOX inhibitor completely halted fungal growth. On the basis of these results, a novel mechanism is presented in which AOX plays a role in the biotrophic development of M. perniciosa and regulates the transition to its necrotrophic stage. Strikingly, this model correlates well with the infection strategy of animal pathogens, particularly Trypanosoma brucei, which uses AOX as a strategy for pathogenicity.
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Affiliation(s)
- Daniela P T Thomazella
- Laboratório de Genômica e Expressão, Departamento de Genética, Evolução e Bioagentes, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CP 6109, Campinas, SP 13083-970, Brazil
| | - Paulo José P L Teixeira
- Laboratório de Genômica e Expressão, Departamento de Genética, Evolução e Bioagentes, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CP 6109, Campinas, SP 13083-970, Brazil
| | - Halley C Oliveira
- Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CP 6109, Campinas, SP 13083-970, Brazil
| | - Elzira E Saviani
- Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CP 6109, Campinas, SP 13083-970, Brazil
| | - Johana Rincones
- Laboratório de Genômica e Expressão, Departamento de Genética, Evolução e Bioagentes, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CP 6109, Campinas, SP 13083-970, Brazil
| | - Isabella M Toni
- Laboratório de Genômica e Expressão, Departamento de Genética, Evolução e Bioagentes, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CP 6109, Campinas, SP 13083-970, Brazil
| | - Osvaldo Reis
- Laboratório de Genômica e Expressão, Departamento de Genética, Evolução e Bioagentes, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CP 6109, Campinas, SP 13083-970, Brazil
| | - Odalys Garcia
- Laboratório de Genômica e Expressão, Departamento de Genética, Evolução e Bioagentes, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CP 6109, Campinas, SP 13083-970, Brazil
| | - Lyndel W Meinhardt
- Sustainable Perennial Crops Laboratory, USDA-ARS, 10300 Baltimore Ave., Bldg. 001, Beltsville, MD 20705-2350, USA
| | - Ione Salgado
- Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CP 6109, Campinas, SP 13083-970, Brazil
| | - Gonçalo A G Pereira
- Laboratório de Genômica e Expressão, Departamento de Genética, Evolução e Bioagentes, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CP 6109, Campinas, SP 13083-970, Brazil
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Grahl N, Dinamarco TM, Willger SD, Goldman GH, Cramer RA. Aspergillus fumigatus mitochondrial electron transport chain mediates oxidative stress homeostasis, hypoxia responses and fungal pathogenesis. Mol Microbiol 2012; 84:383-99. [PMID: 22443190 DOI: 10.1111/j.1365-2958.2012.08034.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
We previously observed that hypoxia is an important component of host microenvironments during pulmonary fungal infections. However, mechanisms of fungal growth in these in vivo hypoxic conditions are poorly understood. Here, we report that mitochondrial respiration is active in hypoxia (1% oxygen) and critical for fungal pathogenesis. We generated Aspergillus fumigatus alternative oxidase (aoxA) and cytochrome C (cycA) null mutants and assessed their ability to tolerate hypoxia, macrophage killing and virulence. In contrast to ΔaoxA, ΔcycA was found to be significantly impaired in conidia germination, growth in normoxia and hypoxia, and displayed attenuated virulence. Intriguingly, loss of cycA results in increased levels of AoxA activity, which results in increased resistance to oxidative stress, macrophage killing and long-term persistence in murine lungs. Thus, our results demonstrate a previously unidentified role for fungal mitochondrial respiration in the pathogenesis of aspergillosis, and lay the foundation for future research into its role in hypoxia signalling and adaptation.
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Affiliation(s)
- Nora Grahl
- Department of Immunology and Infectious Diseases, Montana State University, Bozeman, MT, USA
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Guerrero-Castillo S, Araiza-Olivera D, Cabrera-Orefice A, Espinasa-Jaramillo J, Gutiérrez-Aguilar M, Luévano-Martínez LA, Zepeda-Bastida A, Uribe-Carvajal S. Physiological uncoupling of mitochondrial oxidative phosphorylation. Studies in different yeast species. J Bioenerg Biomembr 2011; 43:323-31. [PMID: 21556887 DOI: 10.1007/s10863-011-9356-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Under non-phosphorylating conditions a high proton transmembrane gradient inhibits the rate of oxygen consumption mediated by the mitochondrial respiratory chain (state IV). Slow electron transit leads to production of reactive oxygen species (ROS) capable of participating in deleterious side reactions. In order to avoid overproducing ROS, mitochondria maintain a high rate of O(2) consumption by activating different exquisitely controlled uncoupling pathways. Different yeast species possess one or more uncoupling systems that work through one of two possible mechanisms: i) Proton sinks and ii) Non-pumping redox enzymes. Proton sinks are exemplified by mitochondrial unspecific channels (MUC) and by uncoupling proteins (UCP). Saccharomyces. cerevisiae and Debaryomyces hansenii express highly regulated MUCs. Also, a UCP was described in Yarrowia lipolytica which promotes uncoupled O(2) consumption. Non-pumping alternative oxido-reductases may substitute for a pump, as in S. cerevisiae or may coexist with a complete set of pumps as in the branched respiratory chains from Y. lipolytica or D. hansenii. In addition, pumps may suffer intrinsic uncoupling (slipping). Promising models for study are unicellular parasites which can turn off their aerobic metabolism completely. The variety of energy dissipating systems in eukaryote species is probably designed to control ROS production in the different environments where each species lives.
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Inoue K, Tsurumi T, Ishii H, Park P, Ikeda K. Cytological evaluation of the effect of azoxystrobin and alternative oxidase inhibitors in Botrytis cinerea. FEMS Microbiol Lett 2011; 326:83-90. [PMID: 22092932 DOI: 10.1111/j.1574-6968.2011.02438.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Revised: 10/09/2011] [Accepted: 10/10/2011] [Indexed: 11/29/2022] Open
Abstract
Azoxystrobin (AZ), a strobilurin-derived fungicide, is known to inhibit mitochondrial respiration in fungi by blocking the electron transport chain in the inner mitochondrial membrane. Germination was strongly inhibited when Botrytis cinerea spore suspension was treated with AZ and the alternative oxidase (AOX) inhibitors, salicylhydroxamic acid (SHAM) and n-propyl gallate. However, chemical death indicators trypan blue and propidium iodide showed that those spores were still alive. When the spore suspension in the AZ and SHAM solution was replaced with distilled water, the germination rate almost recovered, at least during the first 2 days of incubation with AZ and SHAM solution. No morphological alteration was detected in the cells treated with AZ and SHAM, especially in mitochondria, using transmission electron microscopy. Therefore, simultaneous application of AZ and AOX inhibitors has a fungistatic, rather than a fungicidal, action.
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Affiliation(s)
- Kanako Inoue
- Stress Cytology Laboratory, Graduate School of Agriculture, Kobe University, Kobe, Japan
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Ruiz OH, Gonzalez A, Almeida AJ, Tamayo D, Garcia AM, Restrepo A, McEwen JG. Alternative oxidase mediates pathogen resistance in Paracoccidioides brasiliensis infection. PLoS Negl Trop Dis 2011; 5:e1353. [PMID: 22039556 PMCID: PMC3201906 DOI: 10.1371/journal.pntd.0001353] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2011] [Accepted: 08/25/2011] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Paracoccidioides brasiliensis is a human thermal dimorphic pathogenic fungus. Survival of P. brasiliensis inside the host depends on the adaptation of this fungal pathogen to different conditions, namely oxidative stress imposed by immune cells. AIMS AND METHODOLOGY In this study, we evaluated the role of alternative oxidase (AOX), an enzyme involved in the intracellular redox balancing, during host-P. brasiliensis interaction. We generated a mitotically stable P. brasiliensis AOX (PbAOX) antisense RNA (aRNA) strain with a 70% reduction in gene expression. We evaluated the relevance of PbAOX during interaction of conidia and yeast cells with IFN-γ activated alveolar macrophages and in a mouse model of infection. Additionally, we determined the fungal cell's viability and PbAOX in the presence of H₂O₂. RESULTS Interaction with IFN-γ activated alveolar macrophages induced higher levels of PbAOX gene expression in PbWt conidia than PbWt yeast cells. PbAOX-aRNA conidia and yeast cells had decreased viability after interaction with macrophages. Moreover, in a mouse model of infection, we showed that absence of wild-type levels of PbAOX in P. brasiliensis results in a reduced fungal burden in lungs at weeks 8 and 24 post-challenge and an increased survival rate. In the presence of H₂O₂, we observed that PbWt yeast cells increased PbAOX expression and presented a higher viability in comparison with PbAOX-aRNA yeast cells. CONCLUSIONS These data further support the hypothesis that PbAOX is important in the fungal defense against oxidative stress imposed by immune cells and is relevant in the virulence of P. brasiliensis.
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Shingu-Vazquez M, Traven A. Mitochondria and fungal pathogenesis: drug tolerance, virulence, and potential for antifungal therapy. Eukaryot Cell 2011; 10:1376-83. [PMID: 21926328 DOI: 10.1128/EC.05184-11] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Recently, mitochondria have been identified as important contributors to the virulence and drug tolerance of human fungal pathogens. In different scenarios, either hypo- or hypervirulence can result from changes in mitochondrial function. Similarly, specific mitochondrial mutations lead to either sensitivity or resistance to antifungal drugs. Here, we provide a synthesis of this emerging field, proposing that mitochondrial function in membrane lipid homeostasis is the common denominator underlying the observed effects of mitochondria in drug tolerance (both sensitivity and resistance). We discuss how the contrasting effects of mitochondrial dysfunction on fungal drug tolerance and virulence could be explained and the potential for targeting mitochondrial factors for future antifungal drug development.
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Zheng C, Choquer M, Zhang B, Ge H, Hu S, Ma H, Chen S. LongSAGE gene-expression profiling of Botrytis cinerea germination suppressed by resveratrol, the major grapevine phytoalexin. Fungal Biol 2011; 115:815-32. [PMID: 21872179 DOI: 10.1016/j.funbio.2011.06.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 06/13/2011] [Accepted: 06/15/2011] [Indexed: 12/11/2022]
Abstract
The ascomycetes Botrytis cinerea is one of the most studied necrotrophic phytopathogens and one of the main fungal parasites of grapevine. As a defense mechanism, grapevine produces a phytoalexin compound, resveratrol, which inhibits germination of the fungal conidium before it can penetrate the plant barriers and lead to host cell necrotrophy. To elucidate the effect of resveratrol on transcriptional regulation in B. cinerea germlings, two LongSAGE (long serial analysis of gene expression) libraries were generated in vitro for gene-expression profiling: 41 428 tags and among them, 15 665 unitags were obtained from resveratrol-treated B. cinerea germlings and 41 358 tags, among them, 16 362 unitags were obtained from non-treated B. cinerea germlings. In-silico analysis showed that about half of these unitags match known genes in the complete B. cinerea genome sequence. Comparison of unitag frequencies between libraries highlighted 110 genes that were transcriptionally regulated in the presence of resveratrol: 53 and 57 genes were significantly down- and upregulated, respectively. Manual curation of their putative functional categories showed that primary metabolism of germinating conidia appears to be markedly affected under resveratrol treatment, along with changes in other putative metabolic pathways, such as resveratrol detoxification and virulence-effector secretion, in B. cinerea germlings. We propose a hypothetical model of cross talk between B. cinerea germinating conidia and resveratrol-producing grapevine at the very early steps of infection.
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Affiliation(s)
- Chuanlin Zheng
- College of Agriculture and Biotechnology, China Agricultural University, Beijing
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Martins VDP, Dinamarco TM, Curti C, Uyemura SA. Classical and alternative components of the mitochondrial respiratory chain in pathogenic fungi as potential therapeutic targets. J Bioenerg Biomembr 2011; 43:81-8. [PMID: 21271279 DOI: 10.1007/s10863-011-9331-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The frequency of opportunistic fungal infection has increased drastically, mainly in patients who are immunocompromised due to organ transplant, leukemia or HIV infection. In spite of this, only a few classes of drugs with a limited array of targets, are available for antifungal therapy. Therefore, more specific and less toxic drugs with new molecular targets is desirable for the treatment of fungal infections. In this context, searching for differences between mitochondrial mammalian hosts and fungi in the classical and alternative components of the mitochondrial respiratory chain may provide new potential therapeutic targets for this purpose.
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Affiliation(s)
- Vicente de Paulo Martins
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
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Martins VP, Dinamarco TM, Soriani FM, Tudella VG, Oliveira SC, Goldman GH, Curti C, Uyemura SA. Involvement of an alternative oxidase in oxidative stress and mycelium-to-yeast differentiation in Paracoccidioides brasiliensis. Eukaryot Cell 2011; 10:237-48. [PMID: 21183691 PMCID: PMC3067407 DOI: 10.1128/ec.00194-10] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2010] [Accepted: 12/10/2010] [Indexed: 11/20/2022]
Abstract
Paracoccidioides brasiliensis is a thermodimorphic human pathogenic fungus that causes paracoccidioidomycosis (PCM), which is the most prevalent systemic mycosis in Latin America. Differentiation from the mycelial to the yeast form (M-to-Y) is an essential step for the establishment of PCM. We evaluated the involvement of mitochondria and intracellular oxidative stress in M-to-Y differentiation. M-to-Y transition was delayed by the inhibition of mitochondrial complexes III and IV or alternative oxidase (AOX) and was blocked by the association of AOX with complex III or IV inhibitors. The expression of P. brasiliensis aox (Pbaox) was developmentally regulated through M-to-Y differentiation, wherein the highest levels were achieved in the first 24 h and during the yeast exponential growth phase; Pbaox was upregulated by oxidative stress. Pbaox was cloned, and its heterologous expression conferred cyanide-resistant respiration in Saccharomyces cerevisiae and Escherichia coli and reduced oxidative stress in S. cerevisiae cells. These results reinforce the role of PbAOX in intracellular redox balancing and demonstrate its involvement, as well as that of other components of the mitochondrial respiratory chain complexes, in the early stages of the M-to-Y differentiation of P. brasiliensis.
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Affiliation(s)
| | | | | | | | - Sergio C. Oliveira
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Gustavo H. Goldman
- Departamento de Ciências Farmacêuticas
- Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE), São Paulo, Brazil
| | - Carlos Curti
- Departamento de Física e Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
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Abstract
Aspergillus species are globally ubiquitous saprophytes found in a variety of ecological niches. Almost 200 species of aspergilli have been identified, less than 20 of which are known to cause human disease. Among them, Aspergillus fumigatus is the most prevalent and is largely responsible for the increased incidence of invasive aspergillosis (IA) in the immunocompromised patient population. IA is a devastating illness, with mortality rates in some patient groups reaching as high as 90%. Studies identifying and assessing the roles of specific factors of A. fumigatus that contribute to the pathogenesis of IA have traditionally focused on single-gene deletion and mutant characterization. In combination with recent large-scale approaches analyzing global fungal responses to distinct environmental or host conditions, these studies have identified many factors that contribute to the overall pathogenic potential of A. fumigatus. Here, we provide an overview of the significant findings regarding A. fumigatus pathogenesis as it pertains to invasive disease.
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