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Ball B, Sukumaran A, Pladwig S, Kazi S, Chan N, Honeywell E, Modrakova M, Geddes-McAlister J. Proteome signatures reveal homeostatic and adaptive oxidative responses by a putative co-chaperone, Wos2, to influence fungal virulence determinants in cryptococcosis. Microbiol Spectr 2024; 12:e0015224. [PMID: 38953322 PMCID: PMC11302251 DOI: 10.1128/spectrum.00152-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 05/27/2024] [Indexed: 07/04/2024] Open
Abstract
The increasing prevalence of invasive fungal pathogens is dramatically changing the clinical landscape of infectious diseases, posing an imminent threat to public health. Specifically, Cryptococcus neoformans, the human opportunistic pathogen, expresses elaborate virulence mechanisms and is equipped with sophisticated adaptation strategies to survive in harsh host environments. This study extensively characterizes Wos2, an Hsp90 co-chaperone homolog, featuring bilateral functioning for both cryptococcal adaptation and the resulting virulence response. In this study, we evaluated the proteome and secretome signatures associated with wos2 deletion in enriched and infection-mimicking conditions to reveal Wos2-dependent regulation of the oxidative stress response through global translational reprogramming. The wos2Δ strain demonstrates defective intracellular and extracellular antioxidant protection systems, measurable through a decreased abundance of critical antioxidant enzymes and reduced growth in the presence of peroxide stress. Additional Wos2-associated stress phenotypes were observed upon fungal challenge with heat shock, osmotic stress, and cell membrane stressors. We demonstrate the importance of Wos2 for intracellular lifestyle of C. neoformans during in vitro macrophage infection and provide evidence for reduced phagosomal replication levels associated with wos2Δ. Accordingly, wos2Δ featured significantly reduced virulence within impacting fungal burden in a murine model of cryptococcosis. Our study highlights a vulnerable point in the fungal chaperone network that offers a therapeutic opportunity to interfere with both fungal virulence and fitness.IMPORTANCEThe global impact of fungal pathogens, both emerging and emerged, is undeniable, and the alarming increase in antifungal resistance rates hampers our ability to protect the global population from deadly infections. For cryptococcal infections, a limited arsenal of antifungals and increasing rates of resistance demand alternative therapeutic strategies, including an anti-virulence approach, which disarms the pathogen of critical virulence factors, empowering the host to remove the pathogens and clear the infection. To this end, we apply state-of-the-art mass spectrometry-based proteomics to evaluate the impact of a recently defined novel co-chaperone, Wos2, toward cryptococcal virulence using in vitro and in vivo models of infection. We explore global proteome and secretome remodeling driven by the protein and uncover the novel role in modulating the fungal oxidative stress response. Complementation of proteome findings with in vitro infectivity assays demonstrated the protective role of Wos2 within the macrophage phagosome, influencing fungal replication and survival. These results underscore differential cryptococcal survivability and weakened patterns of dissemination in the absence of wos2. Overall, our study establishes Wos2 as an important contributor to fungal pathogenesis and warrants further research into critical proteins within global stress response networks as potential druggable targets to reduce fungal virulence and clear infection.
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Affiliation(s)
- Brianna Ball
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Arjun Sukumaran
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Samanta Pladwig
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Samiha Kazi
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Norris Chan
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Effie Honeywell
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Manuela Modrakova
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
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2
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Mukherjee A, Ghosh KK, Chakrabortty S, Gulyás B, Padmanabhan P, Ball WB. Mitochondrial Reactive Oxygen Species in Infection and Immunity. Biomolecules 2024; 14:670. [PMID: 38927073 PMCID: PMC11202257 DOI: 10.3390/biom14060670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Revised: 06/04/2024] [Accepted: 06/05/2024] [Indexed: 06/28/2024] Open
Abstract
Reactive oxygen species (ROS) contain at least one oxygen atom and one or more unpaired electrons and include singlet oxygen, superoxide anion radical, hydroxyl radical, hydroperoxyl radical, and free nitrogen radicals. Intracellular ROS can be formed as a consequence of several factors, including ultra-violet (UV) radiation, electron leakage during aerobic respiration, inflammatory responses mediated by macrophages, and other external stimuli or stress. The enhanced production of ROS is termed oxidative stress and this leads to cellular damage, such as protein carbonylation, lipid peroxidation, deoxyribonucleic acid (DNA) damage, and base modifications. This damage may manifest in various pathological states, including ageing, cancer, neurological diseases, and metabolic disorders like diabetes. On the other hand, the optimum levels of ROS have been implicated in the regulation of many important physiological processes. For example, the ROS generated in the mitochondria (mitochondrial ROS or mt-ROS), as a byproduct of the electron transport chain (ETC), participate in a plethora of physiological functions, which include ageing, cell growth, cell proliferation, and immune response and regulation. In this current review, we will focus on the mechanisms by which mt-ROS regulate different pathways of host immune responses in the context of infection by bacteria, protozoan parasites, viruses, and fungi. We will also discuss how these pathogens, in turn, modulate mt-ROS to evade host immunity. We will conclude by briefly giving an overview of the potential therapeutic approaches involving mt-ROS in infectious diseases.
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Affiliation(s)
- Arunima Mukherjee
- Department of Biological Sciences, School of Engineering and Sciences, SRM University AP Andhra Pradesh, Guntur 522502, Andhra Pradesh, India;
| | - Krishna Kanta Ghosh
- Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, 59 Nanyang Drive, Singapore 636921, Singapore; (K.K.G.); (B.G.)
| | - Sabyasachi Chakrabortty
- Department of Chemistry, School of Engineering and Sciences, SRM University AP Andhra Pradesh, Guntur 522502, Andhra Pradesh, India;
| | - Balázs Gulyás
- Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, 59 Nanyang Drive, Singapore 636921, Singapore; (K.K.G.); (B.G.)
- Cognitive Neuroimaging Centre, 59 Nanyang Drive, Nanyang Technological University, Singapore 636921, Singapore
- Department of Clinical Neuroscience, Karolinska Institute, 17176 Stockholm, Sweden
| | - Parasuraman Padmanabhan
- Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, 59 Nanyang Drive, Singapore 636921, Singapore; (K.K.G.); (B.G.)
- Cognitive Neuroimaging Centre, 59 Nanyang Drive, Nanyang Technological University, Singapore 636921, Singapore
| | - Writoban Basu Ball
- Department of Biological Sciences, School of Engineering and Sciences, SRM University AP Andhra Pradesh, Guntur 522502, Andhra Pradesh, India;
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3
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Edrich ESM, Duvenage L, Gourlay CW. Alternative Oxidase - Aid or obstacle to combat the rise of fungal pathogens? BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 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] [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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4
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Sharma R, Gibb AA, Barnts K, Elrod JW, Puri S. Alternative oxidase promotes high iron tolerance in Candida albicans. Microbiol Spectr 2023; 11:e0215723. [PMID: 37929974 PMCID: PMC10714975 DOI: 10.1128/spectrum.02157-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 10/10/2023] [Indexed: 11/07/2023] Open
Abstract
IMPORTANCE The yeast C. albicans exhibits metabolic flexibility for adaptability to host niches with varying availability of nutrients including essential metals like iron. For example, blood is iron deplete, while the oral cavity and the intestinal lumen are considered iron replete. We show here that C. albicans can tolerate very high levels of environmental iron, despite an increase in high iron-induced reactive oxygen species (ROS) that it mitigates with the help of a unique oxidase, known as alternative oxidase (AOX). High iron induces AOX1/2 that limits mitochondrial accumulation of ROS. Genetic elimination of AOX1/2 resulted in diminished virulence during oropharyngeal candidiasis in high iron mice. Since human mitochondria lack AOX protein, it represents a unique target for treatment of fungal infections.
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Affiliation(s)
- Rishabh Sharma
- Oral Microbiome Research Laboratory, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania, USA
| | - Andrew A. Gibb
- Department of Cardiovascular Sciences, Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
| | - Kelcie Barnts
- Oral and Maxillofacial Pathology, Medicine and Surgery, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania, USA
| | - John W. Elrod
- Department of Cardiovascular Sciences, Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania, USA
| | - Sumant Puri
- Oral Microbiome Research Laboratory, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania, USA
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5
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Liu Z, Basso P, Hossain S, Liston SD, Robbins N, Whitesell L, Noble SM, Cowen LE. Multifactor transcriptional control of alternative oxidase induction integrates diverse environmental inputs to enable fungal virulence. Nat Commun 2023; 14:4528. [PMID: 37500616 PMCID: PMC10374912 DOI: 10.1038/s41467-023-40209-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 07/17/2023] [Indexed: 07/29/2023] Open
Abstract
Metabolic flexibility enables fungi to invade challenging host environments. In Candida albicans, a common cause of life-threatening infections in humans, an important contributor to flexibility is alternative oxidase (Aox) activity. Dramatic induction of this activity occurs under respiratory-stress conditions, which impair the classical electron transport chain (ETC). Here, we show that deletion of the inducible AOX2 gene cripples C. albicans virulence in mice by increasing immune recognition. To investigate further, we examined transcriptional regulation of AOX2 in molecular detail under host-relevant, ETC-inhibitory conditions. We found that multiple transcription factors, including Rtg1/Rtg3, Cwt1/Zcf11, and Zcf2, bind and regulate the AOX2 promoter, conferring thousand-fold levels of inducibility to AOX2 in response to distinct environmental stressors. Further dissection of this complex promoter revealed how integration of stimuli ranging from reactive species of oxygen, nitrogen, and sulfur to reduced copper availability is achieved at the transcriptional level to regulate AOX2 induction and enable pathogenesis.
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Affiliation(s)
- Zhongle Liu
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Pauline Basso
- UCSF Department of Microbiology & Immunology, San Francisco, CA, USA
| | - Saif Hossain
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Sean D Liston
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Nicole Robbins
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Luke Whitesell
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Suzanne M Noble
- UCSF Department of Microbiology & Immunology, San Francisco, CA, USA.
- UCSF Department of Medicine, Division of Infectious Diseases, San Francisco, CA, USA.
| | - Leah E Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada.
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6
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Sendra KM, Watson AK, Kozhevnikova E, Moore AL, Embley TM, Hirt RP. Inhibition of mitosomal alternative oxidase causes lifecycle arrest of early-stage Trachipleistophora hominis meronts during intracellular infection of mammalian cells. PLoS Pathog 2022; 18:e1011024. [PMID: 36538568 PMCID: PMC9767352 DOI: 10.1371/journal.ppat.1011024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 11/24/2022] [Indexed: 12/24/2022] Open
Abstract
Mitosomes are highly reduced forms of mitochondria which have lost two of the 'defining' features of the canonical organelle, the mitochondrial genome, and the capacity to generate energy in the form of ATP. Mitosomes are found in anaerobic protists and obligate parasites and, in most of the studied organisms, have a conserved function in the biosynthesis of iron-sulfur clusters (ISC) that are indispensable cofactors of many essential proteins. The genomes of some mitosome-bearing human pathogenic Microsporidia encode homologues of an alternative oxidase (AOX). This mitochondrial terminal respiratory oxidase is absent from the human host, and hence is a potential target for the development of new antimicrobial agents. Here we present experimental evidence for the mitosomal localization of AOX in the microsporidian Trachipleistophora hominis and demonstrate that it has an important role during the parasite's life cycle progression. Using a recently published methodology for synchronising T. hominis infection of mammalian cell lines, we demonstrated specific inhibition of T. hominis early meront growth and replication by an AOX inhibitor colletochlorin B. Treatment of T. hominis-infected host cells with the drug also inhibited re-infection by newly formed dispersive spores. Addition of the drug during the later stages of the parasite life cycle, when our methods suggest that AOX is not actively produced and T. hominis mitosomes are mainly active in Fe/S cluster biosynthesis, had no inhibitory effects on the parasites. Control experiments with the AOX-deficient microsporidian species Encephalitozoon cuniculi, further demonstrated the specificity of inhibition by the drug. Using the same methodology, we demonstrate effects of two clinically used anti-microsporidian drugs albendazole and fumagillin on the cell biology and life cycle progression of T. hominis infecting mammalian host cells. In summary, our results reveal that T. hominis mitosomes have an active role to play in the progression of the parasite life cycle as well as an important role in the biosynthesis of essential Fe/S clusters. Our work also demonstrates that T. hominis is a useful model for testing the efficacy of therapeutic agents and for studying the physiology and cell biology of microsporidian parasites growing inside infected mammalian cells.
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Affiliation(s)
- Kacper M. Sendra
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Andrew K. Watson
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | | | - Anthony L. Moore
- Department of Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Falmer, Brighton, United Kingdom
| | - T. Martin Embley
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Robert P. Hirt
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
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Figueiredo J, Santos RB, Guerra-Guimarães L, Leclercq CC, Renaut J, Malhó R, Figueiredo A. An in-planta comparative study of Plasmopara viticola proteome reveals different infection strategies towards susceptible and Rpv3-mediated resistance hosts. Sci Rep 2022; 12:20794. [PMID: 36456634 PMCID: PMC9715676 DOI: 10.1038/s41598-022-25164-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 11/25/2022] [Indexed: 12/03/2022] Open
Abstract
Plasmopara viticola, an obligate biotrophic oomycete, is the causal agent of one of the most harmful grapevine diseases, downy mildew. Within this pathosystem, much information is gathered on the host, as characterization of pathogenicity and infection strategy of a biotrophic pathogen is quite challenging. Molecular insights into P. viticola development and pathogenicity are just beginning to be uncovered, mainly by transcriptomic studies. Plasmopara viticola proteome and secretome were only predicted based on transcriptome data. In this study, we have identified the in-planta proteome of P. viticola during infection of a susceptible ('Trincadeira') and a Rpv3-mediated resistance ('Regent') grapevine cultivar. Four hundred and twenty P. viticola proteins were identified on a label-free mass spectrometry-based approach of the apoplastic fluid of grapevine leaves. Overall, our study suggests that, in the compatible interaction, P. viticola manipulates salicylic-acid pathway and isoprenoid biosynthesis to enhance plant colonization. Furthermore, during the incompatible interaction, development-associated proteins increased while oxidoreductases protect P. viticola from ROS-associated plant defence mechanism. Up to our knowledge this is the first in-planta proteome characterization of this biotrophic pathogen, thus this study will open new insights into our understanding of this pathogen colonization strategy of both susceptible and Rpv3-mediated resistance grapevine genotypes.
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Affiliation(s)
- Joana Figueiredo
- Grapevine Pathogen Systems Lab, Plant Biology Department, BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016, Lisboa, Portugal.
- Plant Biology Department, BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016, Lisboa, Portugal.
| | - Rita B Santos
- Grapevine Pathogen Systems Lab, Plant Biology Department, BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016, Lisboa, Portugal
- Plant Biology Department, BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016, Lisboa, Portugal
| | - Leonor Guerra-Guimarães
- CIFC - Centro de Investigação das Ferrugens Do Cafeeiro, Instituto Superior de Agronomia, Universidade de Lisboa, 1349-017, Lisboa, Portugal
- LEAF - Linking Landscape, Environment, Agriculture and Food & Associated Laboratory TERRA, Instituto Superior de Agronomia, Universidade de Lisboa, 1349-017, Lisboa, Portugal
| | - Céline C Leclercq
- Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, 4362, Esch-Sur-Alzette, Luxembourg
| | - Jenny Renaut
- Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, 4362, Esch-Sur-Alzette, Luxembourg
| | - Rui Malhó
- Plant Biology Department, BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016, Lisboa, Portugal
| | - Andreia Figueiredo
- Grapevine Pathogen Systems Lab, Plant Biology Department, BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016, Lisboa, Portugal
- Plant Biology Department, BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016, Lisboa, Portugal
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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. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 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] [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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Targeting the alternative oxidase (AOX) for human health and food security, a pharmaceutical and agrochemical target or a rescue mechanism? Biochem J 2022; 479:1337-1359. [PMID: 35748702 PMCID: PMC9246349 DOI: 10.1042/bcj20180192] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [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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10
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Flores-Cotera LB, Chávez-Cabrera C, Martínez-Cárdenas A, Sánchez S, García-Flores OU. Deciphering the mechanism by which the yeast Phaffia rhodozyma responds adaptively to environmental, nutritional, and genetic cues. J Ind Microbiol Biotechnol 2021; 48:kuab048. [PMID: 34302341 PMCID: PMC8788774 DOI: 10.1093/jimb/kuab048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 07/16/2021] [Indexed: 11/13/2022]
Abstract
Phaffia rhodozyma is a basidiomycetous yeast that synthesizes astaxanthin (ASX), which is a powerful and highly valuable antioxidant carotenoid pigment. P. rhodozyma cells accrue ASX and gain an intense red-pink coloration when faced with stressful conditions such as nutrient limitations (e.g., nitrogen or copper), the presence of toxic substances (e.g., antimycin A), or are affected by mutations in the genes that are involved in nitrogen metabolism or respiration. Since cellular accrual of ASX occurs under a wide variety of conditions, this yeast represents a valuable model for studying the growth conditions that entail oxidative stress for yeast cells. Recently, we proposed that ASX synthesis can be largely induced by conditions that lead to reduction-oxidation (redox) imbalances, particularly the state of the NADH/NAD+ couple together with an oxidative environment. In this work, we review the multiple known conditions that elicit ASX synthesis expanding on the data that we formerly examined. When considered alongside the Mitchell's chemiosmotic hypothesis, the study served to rationalize the induction of ASX synthesis and other adaptive cellular processes under a much broader set of conditions. Our aim was to propose an underlying mechanism that explains how a broad range of divergent conditions converge to induce ASX synthesis in P. rhodozyma. The mechanism that links the induction of ASX synthesis with the occurrence of NADH/NAD+ imbalances may help in understanding how other organisms detect any of a broad array of stimuli or gene mutations, and then adaptively respond to activate numerous compensatory cellular processes.
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Affiliation(s)
- Luis B Flores-Cotera
- Department of Biotechnology and Bioengineering, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, México city 07360, México
| | - Cipriano Chávez-Cabrera
- Department of Biotechnology and Bioengineering, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, México city 07360, México
| | - Anahi Martínez-Cárdenas
- Department of Biotechnology and Bioengineering, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, México city 07360, México
| | - Sergio Sánchez
- Department of Molecular Biology and Biotechnology, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México city 04510, México
| | - Oscar Ulises García-Flores
- Department of Biotechnology and Bioengineering, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, México city 07360, México
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11
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Phenotypic Plasticity in the Productions of Virulence Factors Within and Among Serotypes in the Cryptococcus neoformans Species Complex. Mycopathologia 2021; 187:65-83. [PMID: 34697686 DOI: 10.1007/s11046-021-00597-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 10/12/2021] [Indexed: 10/20/2022]
Abstract
The Cryptococcus neoformans species complex (CNSC) is a common opportunistic human fungal pathogen and the most frequent cause of fungal meningitis. There are three major serotypes in CNSC: A, D, and their hybrids AD, and they have different geographic distributions and medical significance. Melanin pigment and a polysaccharide capsule are the two major virulence factors in CNSC. However, the relationships between serotype and virulence factor production and how environmental factors might impact their relationships are not known. This study investigated the expressions of melanin and capsular polysaccharide in a genetically diverse group of CNSC strains and how their phenotypic expressions were influenced by oxidative and nitrosative stress levels. We found significant differences in melanin and capsular polysaccharide productions among serotypes and across stress conditions. Under oxidative stress, the laboratory hybrids exhibited the highest phenotypic plasticity for melanin production while serotype A showed the highest for capsular polysaccharide production. In contrast, serotype D exhibited the highest phenotypic plasticity for capsular polysaccharide production and clinical serotype AD the highest phenotypic plasticity for melanin production under nitrosative stress. These results demonstrated that different serotypes have different environmental condition-specific mechanisms to modulate the expression of virulence factors.
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12
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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] [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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Oxidative Stress Causes Vacuolar Fragmentation in the Human Fungal Pathogen Cryptococcus neoformans. J Fungi (Basel) 2021; 7:jof7070523. [PMID: 34210104 PMCID: PMC8305764 DOI: 10.3390/jof7070523] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/07/2021] [Accepted: 06/26/2021] [Indexed: 02/04/2023] Open
Abstract
Vacuoles are dynamic cellular organelles, and their morphology is altered by various stimuli or stresses. Vacuoles play an important role in the physiology and virulence of many fungal pathogens. For example, a Cryptococcus neoformans mutant deficient in vacuolar functions showed significantly reduced expression of virulence factors such as capsule and melanin synthesis and was avirulent in a mouse model of cryptococcosis. In the current study, we found significantly increased vacuolar fragmentation in the C. neoformans mutants lacking SOD1 or SOD2, which respectively encode Zn, Cu-superoxide dismutase and Mn-superoxide dismutase. The sod2 mutant showed a greater level of vacuole fragmentation than the sod1 mutant. We also observed that the vacuoles were highly fragmented when wild-type cells were grown in a medium containing high concentrations of iron, copper, or zinc. Moreover, elevated temperature and treatment with the antifungal drug fluconazole caused increased vacuolar fragmentation. These conditions also commonly cause an increase in the levels of intracellular reactive oxygen species in the fungus, suggesting that vacuoles are fragmented in response to oxidative stress. Furthermore, we observed that Sod2 is not only localized in mitochondria but also in the cytoplasm within phagocytosed C. neoformans cells, possibly due to copper or iron limitation.
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Lin J, Zangi M, Kumar TVH, Shakar Reddy M, Reddy LVR, Sadhukhan SK, Bradley DP, Moreira-Walsh B, Edwards TC, O’Dea AT, Tavis JE, Meyers MJ, Donlin MJ. Synthetic Derivatives of Ciclopirox are Effective Inhibitors of Cryptococcus neoformans. ACS OMEGA 2021; 6:8477-8487. [PMID: 33817509 PMCID: PMC8015083 DOI: 10.1021/acsomega.1c00273] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 02/09/2021] [Indexed: 05/04/2023]
Abstract
Opportunistic fungal infections caused by Cryptococcus neoformans are a significant source of mortality in immunocompromised patients. They are challenging to treat because of a limited number of antifungal drugs, and novel and more effective anticryptococcal therapies are needed. Ciclopirox olamine, a N-hydroxypyridone, has been in use as an approved therapeutic agent for the treatment of topical fungal infections for more than two decades. It is a fungicide, with broad activity across multiple fungal species. We synthesized 10 N-hydroxypyridone derivatives to develop an initial structure-activity understanding relative to efficacy as a starting point for the development of systemic antifungals. We screened the derivatives for antifungal activity against C. neoformans and Cryptococcus gattii and counter-screened for specificity in Candida albicans and two Malassezia species. Eight of the ten show inhibition at 1-3 μM concentration (0.17-0.42 μg per mL) in both Cryptococcus species and in C. albicans, but poor activity in the Malassezia species. In C. neoformans, the N-hydroxypyridones are fungicides, are not antagonistic with either fluconazole or amphotericin B, and are synergistic with multiple inhibitors of the mitochondrial electron transport chain. They appear to function primarily by chelating iron within the active site of iron-dependent enzymes. This preliminary structure-activity relationship points to the need for a lipophilic functional group at position six of the N-hydroxypyridone ring and identifies positions four and six as sites where further substitution may be tolerated. These molecules provide a clear starting point for future optimization for efficacy and target identification.
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Affiliation(s)
- Jeffrey Lin
- Department
of Biology, Saint Louis University, 3507 Laclede Avenue, St. Louis, Missouri 63103, United States
| | - Maryam Zangi
- Department
of Chemistry, Saint Louis University, 3501 Laclede Avenue, St. Louis, Missouri 63103, United States
| | | | - Makala Shakar Reddy
- Medicinal
Chemistry Division, Albany Molecular Research
Inc., MN Park, Turkpally
Shamirpet Mandal, Genome Valley, Hyderabad 500078, India
| | - Lingala Vijaya Raghava Reddy
- Medicinal
Chemistry Division, Albany Molecular Research
Inc., MN Park, Turkpally
Shamirpet Mandal, Genome Valley, Hyderabad 500078, India
| | - Subir Kumar Sadhukhan
- Medicinal
Chemistry Division, Albany Molecular Research
Inc., MN Park, Turkpally
Shamirpet Mandal, Genome Valley, Hyderabad 500078, India
| | - Daniel P. Bradley
- Department
of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, 1100 South Grand Blvd., St. Louis, Missouri 63104, United States
- Institute
for Drug and Biotherapeutic Innovation, Saint Louis University, St. Louis, Missouri 63103, United States
| | - Brenda Moreira-Walsh
- Edward
A. Doisy Department of Biochemistry, Saint
Louis University School of Medicine, 1100 South Grand Blvd., St. Louis, Missouri 63104, United
States
| | - Tiffany C. Edwards
- Department
of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, 1100 South Grand Blvd., St. Louis, Missouri 63104, United States
| | - Austin T. O’Dea
- Department
of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, 1100 South Grand Blvd., St. Louis, Missouri 63104, United States
| | - John E. Tavis
- Department
of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, 1100 South Grand Blvd., St. Louis, Missouri 63104, United States
- Institute
for Drug and Biotherapeutic Innovation, Saint Louis University, St. Louis, Missouri 63103, United States
| | - Marvin J. Meyers
- Department
of Chemistry, Saint Louis University, 3501 Laclede Avenue, St. Louis, Missouri 63103, United States
- Institute
for Drug and Biotherapeutic Innovation, Saint Louis University, St. Louis, Missouri 63103, United States
| | - Maureen J. Donlin
- Edward
A. Doisy Department of Biochemistry, Saint
Louis University School of Medicine, 1100 South Grand Blvd., St. Louis, Missouri 63104, United
States
- Institute
for Drug and Biotherapeutic Innovation, Saint Louis University, St. Louis, Missouri 63103, United States
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15
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Romero-Aguilar L, Cárdenas-Monroy C, Garrido-Bazán V, Aguirre J, Guerra-Sánchez G, Pardo JP. On the use of n-octyl gallate and salicylhydroxamic acid to study the alternative oxidase role. Arch Biochem Biophys 2020; 694:108603. [PMID: 32986977 DOI: 10.1016/j.abb.2020.108603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 08/28/2020] [Accepted: 09/24/2020] [Indexed: 10/23/2022]
Abstract
The alternative oxidase (AOX) catalyzes the transfer of electrons from ubiquinol to oxygen without the translocation of protons across the inner mitochondrial membrane. This enzyme has been proposed to participate in the regulation of cell growth, sporulation, yeast-mycelium transition, resistance to reactive oxygen species, infection, and production of secondary metabolites. Two approaches have been used to evaluate AOX function: incubation of cells for long periods of time with AOX inhibitors or deletion of AOX gene. However, AOX inhibitors might have different targets. To test non-specific effects of n-octyl gallate (nOg) and salicylhydroxamic acid (SHAM) on fungal physiology we measured the growth and respiratory capacity of two fungal strains lacking (Ustilago maydis-Δaox and Saccharomyces cerevisiae) and three species containing the AOX gene (U. maydis WT, Debaryomyces hansenii, and Aspergillus nidulans). For U. maydis, a strong inhibition of growth and respiratory capacity by SHAM was observed, regardless of the presence of AOX. Similarly, A. nidulans mycelial growth was inhibited by low concentrations of nOg independently of AOX expression. In contrast, these inhibitors had no effect or had a minor effect on S. cerevisiae and D. hansenii growth. These results show that nOg and SHAM have AOX independent effects which vary in different microorganisms, indicating that studies based on long-term incubation of cells with these inhibitors should be considered as inconclusive.
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Affiliation(s)
- Lucero Romero-Aguilar
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Avenida Universidad 3000, Copilco, Cd. Universitaria, Coyoacán, 04510, Ciudad de México, Mexico
| | - Christian Cárdenas-Monroy
- Ciencia Forense, Universidad Nacional Autónoma de México, Avenida Universidad 3000, Copilco, Cd. Universitaria, Coyoacán, 04510, Ciudad de México, Mexico
| | - Verónica Garrido-Bazán
- Departamento de Biología Celular y del Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Avenida Universidad 3000, Copilco, Cd. Universitaria, Coyoacán, 04510, Ciudad de México, Mexico
| | - Jesus Aguirre
- Departamento de Biología Celular y del Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Avenida Universidad 3000, Copilco, Cd. Universitaria, Coyoacán, 04510, Ciudad de México, Mexico
| | - Guadalupe Guerra-Sánchez
- Departamento de Microbiología, Laboratorio de Bioquímica y Biotecnología de Hongos, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Carpio y Plan de Ayala S/N., Miguel Hidalgo, 11350, Ciudad de México, Mexico
| | - Juan Pablo Pardo
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Avenida Universidad 3000, Copilco, Cd. Universitaria, Coyoacán, 04510, Ciudad de México, Mexico.
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16
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Yu QK, Han LT, Wu YJ, Liu TB. The Role of Oxidoreductase-Like Protein Olp1 in Sexual Reproduction and Virulence of Cryptococcus neoformans. Microorganisms 2020; 8:microorganisms8111730. [PMID: 33158259 PMCID: PMC7694259 DOI: 10.3390/microorganisms8111730] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 10/31/2020] [Accepted: 11/03/2020] [Indexed: 11/16/2022] Open
Abstract
Cryptococcus neoformans is a basidiomycete human fungal pathogen causing lethal meningoencephalitis, mainly in immunocompromised patients. Oxidoreductases are a class of enzymes that catalyze redox, playing a crucial role in biochemical reactions. In this study, we identified one Cryptococcus oxidoreductase-like protein-encoding gene OLP1 and investigated its role in the sexual reproduction and virulence of C. neoformans. Gene expression patterns analysis showed that the OLP1 gene was expressed in each developmental stage of Cryptococcus, and the Olp1 protein was located in the cytoplasm of Cryptococcus cells. Although it produced normal major virulence factors such as melanin and capsule, the olp1Δ mutants showed growth defects on the yeast extract peptone dextrose (YPD) medium supplemented with lithium chloride (LiCl) and 5-fluorocytosine (5-FC). The fungal mating analysis showed that Olp1 is also essential for fungal sexual reproduction, as olp1Δ mutants show significant defects in hyphae growth and basidiospores production during bisexual reproduction. The fungal nuclei imaging showed that during the bilateral mating of olp1Δ mutants, the nuclei failed to undergo meiosis after fusion in the basidia, indicating that Olp1 is crucial for regulating meiosis during mating. Moreover, Olp1 was also found to be required for fungal virulence in C. neoformans, as the olp1Δ mutants showed significant virulence attenuation in a murine inhalation model. In conclusion, our results showed that the oxidoreductase-like protein Olp1 is required for both fungal sexual reproduction and virulence in C. neoformans.
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Affiliation(s)
- Qi-Kun Yu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; (Q.-K.Y.); (L.-T.H.); (Y.-J.W.)
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China
| | - Lian-Tao Han
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; (Q.-K.Y.); (L.-T.H.); (Y.-J.W.)
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China
| | - Yu-Juan Wu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; (Q.-K.Y.); (L.-T.H.); (Y.-J.W.)
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China
| | - Tong-Bao Liu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; (Q.-K.Y.); (L.-T.H.); (Y.-J.W.)
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China
- Correspondence: ; Tel.: +86-23-6825-1088
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17
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A Cytoplasmic Heme Sensor Illuminates the Impacts of Mitochondrial and Vacuolar Functions and Oxidative Stress on Heme-Iron Homeostasis in Cryptococcus neoformans. mBio 2020; 11:mBio.00986-20. [PMID: 32723917 PMCID: PMC7387795 DOI: 10.1128/mbio.00986-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Invasive fungal diseases are increasing in frequency, and new drug targets and antifungal drugs are needed to bolster therapy. The mechanisms by which pathogens obtain critical nutrients such as iron from heme during host colonization represent a promising target for therapy. In this study, we employed a fluorescent heme sensor to investigate heme homeostasis in Cryptococcus neoformans. We demonstrated that endocytosis is a key aspect of heme acquisition and that vacuolar and mitochondrial functions are important in regulating the pool of available heme in cells. Stress generated by oxidative conditions impacts the heme pool, as do the drugs artemisinin and metformin; these drugs have heme-related activities and are in clinical use for malaria and diabetes, respectively. Overall, our study provides insights into mechanisms of fungal heme acquisition and demonstrates the utility of the heme sensor for drug characterization in support of new therapies for fungal diseases. Pathogens must compete with hosts to acquire sufficient iron for proliferation during pathogenesis. The pathogenic fungus Cryptococcus neoformans is capable of acquiring iron from heme, the most abundant source in vertebrate hosts, although the mechanisms of heme sensing and acquisition are not entirely understood. In this study, we adopted a chromosomally encoded heme sensor developed for Saccharomyces cerevisiae to examine cytosolic heme levels in C. neoformans using fluorescence microscopy, fluorimetry, and flow cytometry. We validated the responsiveness of the sensor upon treatment with exogenous hemin, during proliferation in macrophages, and in strains defective for endocytosis. We then used the sensor to show that vacuolar and mitochondrial dysregulation and oxidative stress reduced the labile heme pool in the cytosol. Importantly, the sensor provided a tool to further demonstrate that the drugs artemisinin and metformin have heme-related activities and the potential to be repurposed for antifungal therapy. Overall, this study provides insights into heme sensing by C. neoformans and establishes a powerful tool to further investigate mechanisms of heme-iron acquisition in the context of fungal pathogenesis.
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18
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The Novel J-Domain Protein Mrj1 Is Required for Mitochondrial Respiration and Virulence in Cryptococcus neoformans. mBio 2020; 11:mBio.01127-20. [PMID: 32518190 PMCID: PMC7373193 DOI: 10.1128/mbio.01127-20] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Cryptococcus neoformans is the causative agent of cryptococcal meningitis, a disease responsible for ∼15% of all HIV-related deaths. Unfortunately, development of antifungal drugs is challenging because potential targets are conserved between humans and C. neoformans. In this context, we characterized a unique J-domain protein, Mrj1, which lacks orthologs in humans. We showed that Mrj1 was required for normal mitochondrial respiration and that mutants lacking Mrj1 were deficient in growth, capsule elaboration, and virulence. Furthermore, we were able to phenocopy the defects in growth and capsule elaboration by inhibiting respiration. This result suggests that the role of Mrj1 in mitochondrial function was responsible for the observed virulence defects and reinforces the importance of mitochondria to fungal pathogenesis. Mitochondria are difficult to target, as their function is also key to human cells; however, Mrj1 presents an opportunity to target a unique fungal protein required for mitochondrial function and virulence in C. neoformans. The opportunistic fungal pathogen Cryptococcus neoformans must adapt to the mammalian environment to establish an infection. Proteins facilitating adaptation to novel environments, such as chaperones, may be required for virulence. In this study, we identified a novel mitochondrial co-chaperone, Mrj1 (mitochondrial respiration J-domain protein 1), necessary for virulence in C. neoformans. The mrj1Δ and J-domain-inactivated mutants had general growth defects at both routine laboratory and human body temperatures and were deficient in the major virulence factor of capsule elaboration. The latter phenotype was associated with cell wall changes and increased capsular polysaccharide shedding. Accordingly, the mrj1Δ mutant was avirulent in a murine model of cryptococcosis. Mrj1 has a mitochondrial localization and co-immunoprecipitated with Qcr2, a core component of complex III of the electron transport chain. The mrj1 mutants were deficient in mitochondrial functions, including growth on alternative carbon sources, growth without iron, and mitochondrial polarization. They were also insensitive to complex III inhibitors and hypersensitive to an alternative oxidase (AOX) inhibitor, suggesting that Mrj1 functions in respiration. In support of this conclusion, mrj1 mutants also had elevated basal oxygen consumption rates which were completely abolished by the addition of the AOX inhibitor, confirming that Mrj1 is required for mitochondrial respiration through complexes III and IV. Furthermore, inhibition of complex III phenocopied the capsule and cell wall defects of the mrj1 mutants. Taken together, these results indicate that Mrj1 is required for normal mitochondrial respiration, a key aspect of adaptation to the host environment and virulence.
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19
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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] [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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20
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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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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21
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Tian F, Lee SY, Woo SY, Chun HS. Alternative Oxidase: A Potential Target for Controlling Aflatoxin Contamination and Propagation of Aspergillus flavus. Front Microbiol 2020; 11:419. [PMID: 32256475 PMCID: PMC7092633 DOI: 10.3389/fmicb.2020.00419] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 02/27/2020] [Indexed: 12/16/2022] Open
Abstract
Aflatoxins are among the most hazardous natural cereal contaminants. These mycotoxins are produced by Aspergillus spp. as polyketide secondary metabolites. Aflatoxigenic fungi including A. flavus express the alternative oxidase (AOX), which introduces a branch in the cytochrome-based electron transfer chain by coupling ubiquinol oxidation directly with the reduction of O2 to H2O. AOX is closely associated with fungal pathogenesis, morphogenesis, stress signaling, and drug resistance and, as recently reported, affects the production of mycotoxins such as sterigmatocystin, the penultimate intermediate in aflatoxin B1 biosynthesis. Thus, AOX might be considered a target for controlling the propagation of and aflatoxin contamination by A. flavus. Hence, this review summarizes the current understanding of fungal AOX and the alternative respiration pathway and the development and potential applications of AOX inhibitors. This review indicates that AOX inhibitors, either alone or in combination with current antifungal agents, are potentially applicable for developing novel, effective antifungal strategies. However, considering the conservation of AOX in fungal and plant cells, a deeper understanding of fungal alternative respiration and fungal AOX structure is needed, along with effective fungal-specific AOX inhibitors.
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Affiliation(s)
- Fei Tian
- Food Toxicology Laboratory, Advanced Food Safety Research Group, BK21 Plus, School of Food Science and Technology, Chung-Ang University, Anseong, South Korea
| | - Sang Yoo Lee
- Food Toxicology Laboratory, Advanced Food Safety Research Group, BK21 Plus, School of Food Science and Technology, Chung-Ang University, Anseong, South Korea
| | - So Young Woo
- Food Toxicology Laboratory, Advanced Food Safety Research Group, BK21 Plus, School of Food Science and Technology, Chung-Ang University, Anseong, South Korea
| | - Hyang Sook Chun
- Food Toxicology Laboratory, Advanced Food Safety Research Group, BK21 Plus, School of Food Science and Technology, Chung-Ang University, Anseong, South Korea
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22
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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, MD.) 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] [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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23
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Lin Z, Wu J, Jamieson PA, Zhang C. Alternative Oxidase Is Involved in the Pathogenicity, Development, and Oxygen Stress Response of Botrytis cinerea. PHYTOPATHOLOGY 2019; 109:1679-1688. [PMID: 31479404 DOI: 10.1094/phyto-01-19-0012-r] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Alternative oxidase (AOX) is a ubiquinol terminal oxidase that is involved in fungal mitochondrial oxidative phosphorylation. In this study, we analyzed the roles of AOX in Botrytis cinerea by generating BcAOX deletion mutants. The mutants exhibited defects in mycelial growth, sporulation, spore germination, and virulence. Furthermore, the sensitivity of the mutants to quinone outside inhibitor fungicides and oxidative stress were increased. All phenotypic variations could be restored in the complemented strain. In summary, these results showed that BcAOX is involved in the regulation for vegetative development, adaptation to environmental stress, and virulence of B. cinerea.
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Affiliation(s)
- Zesong Lin
- Department of Crop Protection, Zhejiang Agriculture and Forest University, Hangzhou 311300, China
| | - Jianyan Wu
- Department of Crop Protection, Zhejiang Agriculture and Forest University, Hangzhou 311300, China
| | - Pierce A Jamieson
- Department of Plant Pathology and Microbiology, and Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX 77843, U.S.A
| | - Chuanqing Zhang
- Department of Crop Protection, Zhejiang Agriculture and Forest University, Hangzhou 311300, China
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24
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The potential of respiration inhibition as a new approach to combat human fungal pathogens. Curr Genet 2019; 65:1347-1353. [PMID: 31172256 PMCID: PMC6820612 DOI: 10.1007/s00294-019-01001-w] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [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 MANAGEMENT SCIENCE 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] [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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26
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Ebiloma GU, Balogun EO, Cueto-Díaz EJ, de Koning HP, Dardonville C. Alternative oxidase inhibitors: Mitochondrion-targeting as a strategy for new drugs against pathogenic parasites and fungi. Med Res Rev 2019; 39:1553-1602. [PMID: 30693533 DOI: 10.1002/med.21560] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 11/07/2018] [Accepted: 12/08/2018] [Indexed: 12/11/2022]
Abstract
The alternative oxidase (AOX) is a ubiquitous terminal oxidase of plants and many fungi, catalyzing the four-electron reduction of oxygen to water alongside the cytochrome-based electron transfer chain. Unlike the classical electron transfer chain, however, the activity of AOX does not generate adenosine triphosphate but has functions such as thermogenesis and stress response. As it lacks a mammalian counterpart, it has been investigated intensely in pathogenic fungi. However, it is in African trypanosomes, which lack cytochrome-based respiration in their infective stages, that trypanosome alternative oxidase (TAO) plays the central and essential role in their energy metabolism. TAO was validated as a drug target decades ago and among the first inhibitors to be identified was salicylhydroxamic acid (SHAM), which produced the expected trypanocidal effects, especially when potentiated by coadministration with glycerol to inhibit anaerobic energy metabolism as well. However, the efficacy of this combination was too low to be of practical clinical use. The antibiotic ascofuranone (AF) proved a much stronger TAO inhibitor and was able to cure Trypanosoma vivax infections in mice without glycerol and at much lower doses, providing an important proof of concept milestone. Systematic efforts to improve the SHAM and AF scaffolds, aided with the elucidation of the TAO crystal structure, provided detailed structure-activity relationship information and reinvigorated the drug discovery effort. Recently, the coupling of mitochondrion-targeting lipophilic cations to TAO inhibitors has dramatically improved drug targeting and trypanocidal activity while retaining target protein potency. These developments appear to have finally signposted the way to preclinical development of TAO inhibitors.
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Affiliation(s)
- Godwin U Ebiloma
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Kyoto, Japan.,Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Emmanuel O Balogun
- Department of Biochemistry, Ahmadu Bello University, Zaria, Nigeria.,Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | | | - Harry P de Koning
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
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27
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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 PMCID: PMC6098058 DOI: 10.1038/s41598-018-30108-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [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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28
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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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29
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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] [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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30
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Ghosh S, Kanwar P, Jha G. Identification of candidate pathogenicity determinants of Rhizoctonia solani AG1-IA, which causes sheath blight disease in rice. Curr Genet 2017; 64:729-740. [PMID: 29196814 DOI: 10.1007/s00294-017-0791-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Revised: 11/24/2017] [Accepted: 11/27/2017] [Indexed: 01/04/2023]
Abstract
Sheath blight disease is one of the predominant diseases of rice and it is caused by the necrotrophic fungal pathogen Rhizoctonia solani. The mechanistic insight about its widespread success as a broad host range pathogen is limited. In this study, we endeavor to identify pathogenicity determinants of R. solani during infection process in rice. Through RNAseq analysis, we identified a total of 65 and 232 R. solani (strain BRS1) genes to be commonly upregulated in three different rice genotypes (PB1, Tetep, and TP309) at establishment and necrotrophic phase, respectively. The induction of genes encoding extracellular protease, ABC transporter, and transcription factors were notable during establishment phase. While during necrotrophic phase, several CAZymes, sugar transporters, cellular metabolism, and protein degradation-related genes were prominently induced. We have also identified few putative secreted effector encoding genes that were upregulated during pathogenesis. The qPCR analysis further validated the phase-specific expression dynamics of some selected putative effectors and pathogenicity-associated genes. Overall, the present study reports identification of key genes and processes that might be crucial for R. solani pathogenesis. The ability to effectively damage host cell wall and survive in hostile plant environment by managing oxidative stress, cytotoxic compounds, etc. is being proposed to be important for pathogenesis of R. solani in rice. The functional characterization of these genes would provide key insights about this important pathosystem and facilitate development of strategies to control this devastating disease.
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Affiliation(s)
- Srayan Ghosh
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Poonam Kanwar
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Gopaljee Jha
- Plant Microbe Interactions Laboratory, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India.
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31
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Yang CL, Wang J, Zou LL. Innate immune evasion strategies against Cryptococcal meningitis caused by Cryptococcus neoformans. Exp Ther Med 2017; 14:5243-5250. [PMID: 29285049 PMCID: PMC5740712 DOI: 10.3892/etm.2017.5220] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 05/31/2017] [Indexed: 12/14/2022] Open
Abstract
As an infectious fungus that affects the respiratory tract, Cryptococcus neoformans (C. neoformans) commonly causes asymptomatic pulmonary infection. C. neoformans may target the brain instead of the lungs and cross the blood-brain barrier (BBB) in the early phase of infection; however, this is dependent on successful evasion of the host innate immune system. During the initial stage of fungal infection, a complex network of innate immune factors are activated. C. neoformans utilizes a number of strategies to overcome the anti-fungal mechanisms of the host innate immune system and cross the BBB. In the present review, the defensive mechanisms of C. neoformans against the innate immune system and its ability to cross the BBB were discussed, with an emphasis on recent insights into the activities of anti-phagocytotic and anti-oxidative factors in C. neoformans.
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Affiliation(s)
- Cheng-Liang Yang
- Translational Neuroscience and Neural Regeneration and Repair Institute, The First Hospital of Yichang, China Three Gorges University, Yichang, Hubei 443002, P.R. China.,Institute of Cell Therapy, The First Hospital of Yichang, China Three Gorges University, Yichang, Hubei 443002, P.R. China
| | - Jun Wang
- Translational Neuroscience and Neural Regeneration and Repair Institute, The First Hospital of Yichang, China Three Gorges University, Yichang, Hubei 443002, P.R. China.,Institute of Cell Therapy, The First Hospital of Yichang, China Three Gorges University, Yichang, Hubei 443002, P.R. China
| | - Li-Li Zou
- Translational Neuroscience and Neural Regeneration and Repair Institute, The First Hospital of Yichang, China Three Gorges University, Yichang, Hubei 443002, P.R. China.,Institute of Cell Therapy, The First Hospital of Yichang, China Three Gorges University, Yichang, Hubei 443002, P.R. China.,Department of Microbiology and Immunology, Medical College, China Three Gorges University, Yichang, Hubei 443002, P.R. China
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32
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Johansson N, Persson KO, Norbeck J, Larsson C. Expression of NADH-oxidases enhances ethylene productivity in Saccharomyces cerevisiae expressing the bacterial EFE. BIOTECHNOL BIOPROC E 2017. [DOI: 10.1007/s12257-016-0602-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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33
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Cárdenas-Monroy CA, Pohlmann T, Piñón-Zárate G, Matus-Ortega G, Guerra G, Feldbrügge M, Pardo JP. The mitochondrial alternative oxidase Aox1 is needed to cope with respiratory stress but dispensable for pathogenic development in Ustilago maydis. PLoS One 2017; 12:e0173389. [PMID: 28273139 PMCID: PMC5342259 DOI: 10.1371/journal.pone.0173389] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 02/20/2017] [Indexed: 12/22/2022] Open
Abstract
The mitochondrial alternative oxidase is an important enzyme that allows respiratory activity and the functioning of the Krebs cycle upon disturbance of the respiration chain. It works as a security valve in transferring excessive electrons to oxygen, thereby preventing potential damage by the generation of harmful radicals. A clear biological function, besides the stress response, has so far convincingly only been shown for plants that use the alternative oxidase to generate heat to distribute volatiles. In fungi it was described that the alternative oxidase is needed for pathogenicity. Here, we investigate expression and function of the alternative oxidase at different stages of the life cycle of the corn pathogen Ustilago maydis (Aox1). Interestingly, expression of Aox1 is specifically induced during the stationary phase suggesting a role at high cell density when nutrients become limiting. Studying deletion strains as well as overexpressing strains revealed that Aox1 is dispensable for normal growth, for cell morphology, for response to temperature stress as well as for filamentous growth and plant pathogenicity. However, during conditions eliciting respiratory stress yeast-like growth as well as hyphal growth is strongly affected. We conclude that Aox1 is dispensable for the normal biology of the fungus but specifically needed to cope with respiratory stress.
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Affiliation(s)
| | - Thomas Pohlmann
- Institute for Microbiology, Cluster of Excellence on Plant Sciences, Department of Biology, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany
| | - Gabriela Piñón-Zárate
- Departamento de Biología Celular y Tisular, Facultad de Medicina, UNAM. Ciudad de México, México
| | - Genaro Matus-Ortega
- Departamento de Bioquímica, Facultad de Medicina, UNAM. Ciudad de México, México
| | - Guadalupe Guerra
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional. Ciudad de México, México
| | - Michael Feldbrügge
- Institute for Microbiology, Cluster of Excellence on Plant Sciences, Department of Biology, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany
| | - Juan Pablo Pardo
- Departamento de Bioquímica, Facultad de Medicina, UNAM. Ciudad de México, México
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34
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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] [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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35
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Vishwakarma A, Dalal A, Tetali SD, Kirti PB, Padmasree K. Genetic engineering of AtAOX1a in Saccharomyces cerevisiae prevents oxidative damage and maintains redox homeostasis. FEBS Open Bio 2016; 6:135-46. [PMID: 27239435 PMCID: PMC4821348 DOI: 10.1002/2211-5463.12028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 12/31/2015] [Accepted: 12/31/2015] [Indexed: 02/02/2023] Open
Abstract
This study aimed to validate the physiological importance of Arabidopsis thaliana alternative oxidase 1a (AtAOX1a) in alleviating oxidative stress using Saccharomyces cerevisiae as a model organism. The AOX1a transformant (pYES2AtAOX1a) showed cyanide resistant and salicylhydroxamic acid (SHAM)‐sensitive respiration, indicating functional expression of AtAOX1a in S. cerevisiae. After exposure to oxidative stress, pYES2AtAOX1a showed better survival and a decrease in reactive oxygen species (ROS) when compared to S. cerevisiae with empty vector (pYES2). Furthermore, pYES2AtAOX1a sustained growth by regulating GPX2 and/or TSA2, and cellular NAD+/NADH ratio. Thus, the expression of AtAOX1a in S. cerevisiae enhances its respiratory tolerance which, in turn, maintains cellular redox homeostasis and protects from oxidative damage.
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Affiliation(s)
- Abhaypratap Vishwakarma
- Department of Plant Sciences School of Life Sciences University of Hyderabad Hyderabad India
| | - Ahan Dalal
- Department of Plant Sciences School of Life Sciences University of Hyderabad Hyderabad India
| | - Sarada Devi Tetali
- Department of Plant Sciences School of Life Sciences University of Hyderabad Hyderabad India
| | | | - Kollipara Padmasree
- Department of Biotechnology and Bioinformatics School of Life Sciences University of Hyderabad Hyderabad India
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36
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The Zinc Finger Protein Mig1 Regulates Mitochondrial Function and Azole Drug Susceptibility in the Pathogenic Fungus Cryptococcus neoformans. mSphere 2016; 1:mSphere00080-15. [PMID: 27303693 PMCID: PMC4863601 DOI: 10.1128/msphere.00080-15] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 12/17/2015] [Indexed: 12/31/2022] Open
Abstract
Fungal pathogens of humans are difficult to treat, and there is a pressing need to identify new targets for antifungal drugs and to obtain a detailed understanding of fungal proliferation in vertebrate hosts. In this study, we examined the roles of the regulatory proteins Mig1 and HapX in mitochondrial function and antifungal drug susceptibility in the fungus Cryptococcus neoformans. This pathogen is a particular threat to the large population of individuals infected with human immunodeficiency virus (HIV). Our analysis revealed regulatory interactions between Mig1 and HapX, and a role for Mig1 in mitochondrial functions, including respiration, tolerance for reactive oxygen species, and expression of genes for iron consumption and iron acquisition functions. Importantly, loss of Mig1 increased susceptibility to the antifungal drug fluconazole, which is commonly used to treat cryptococcal disease. These studies highlight an association between mitochondrial dysfunction and drug susceptibility that may provide new targets for the development of antifungal drugs. The opportunistic pathogen Cryptococcus neoformans causes fungal meningoencephalitis in immunocompromised individuals. In previous studies, we found that the Hap complex in this pathogen represses genes encoding mitochondrial respiratory functions and tricarboxylic acid (TCA) cycle components under low-iron conditions. The orthologous Hap2/3/4/5 complex in Saccharomyces cerevisiae exerts a regulatory influence on mitochondrial functions, and Hap4 is subject to glucose repression via the carbon catabolite repressor Mig1. In this study, we explored the regulatory link between a candidate ortholog of the Mig1 protein and the HapX component of the Hap complex in C. neoformans. This analysis revealed repression of MIG1 by HapX and activation of HAPX by Mig1 under low-iron conditions and Mig1 regulation of mitochondrial functions, including respiration, tolerance for reactive oxygen species, and expression of genes for iron consumption and iron acquisition functions. Consistently with these regulatory functions, a mig1Δ mutant had impaired growth on inhibitors of mitochondrial respiration and inducers of ROS. Furthermore, deletion of MIG1 provoked a dysregulation in nutrient sensing via the TOR pathway and impacted the pathway for cell wall remodeling. Importantly, loss of Mig1 increased susceptibility to fluconazole, thus further establishing a link between azole antifungal drugs and mitochondrial function. Mig1 and HapX were also required together for survival in macrophages, but Mig1 alone had a minimal impact on virulence in mice. Overall, these studies provide novel insights into a HapX/Mig1 regulatory network and reinforce an association between mitochondrial dysfunction and drug susceptibility that may provide new targets for the development of antifungal drugs. IMPORTANCE Fungal pathogens of humans are difficult to treat, and there is a pressing need to identify new targets for antifungal drugs and to obtain a detailed understanding of fungal proliferation in vertebrate hosts. In this study, we examined the roles of the regulatory proteins Mig1 and HapX in mitochondrial function and antifungal drug susceptibility in the fungus Cryptococcus neoformans. This pathogen is a particular threat to the large population of individuals infected with human immunodeficiency virus (HIV). Our analysis revealed regulatory interactions between Mig1 and HapX, and a role for Mig1 in mitochondrial functions, including respiration, tolerance for reactive oxygen species, and expression of genes for iron consumption and iron acquisition functions. Importantly, loss of Mig1 increased susceptibility to the antifungal drug fluconazole, which is commonly used to treat cryptococcal disease. These studies highlight an association between mitochondrial dysfunction and drug susceptibility that may provide new targets for the development of antifungal drugs.
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37
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Horn IR, van Rijn M, Zwetsloot TJJ, Basmagi S, Dirks-Mulder A, van Leeuwen WB, Ravensberg WJ, Gravendeel B. Development of a multiplex Q-PCR to detect Trichoderma harzianum Rifai strain T22 in plant roots. J Microbiol Methods 2016; 121:44-9. [PMID: 26747625 DOI: 10.1016/j.mimet.2015.12.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 12/17/2015] [Accepted: 12/17/2015] [Indexed: 11/16/2022]
Abstract
The fungal species Trichoderma harzianum is widely used as a biological agent in crop protection. To verify the continued presence of this fungus on plant roots manually inoculated with T. harzianum strain T22, a Q-PCR was designed using specific probes for this particular strain. To develop these molecular diagnostic tools, genome mining was first carried out to retrieve putative new regions by which different strains of T. harzianum could be distinguished. Subsequently, Sanger sequencing of the L-aminoacid oxidase gene (aox1) in T. harzianum was applied to determine the mutations differing between various strains isolated from the Trichoderma collection of Koppert Biological Systems. Based on the sequence information obtained, a set of hydrolysis probes was subsequently developed which discriminated T. harzianum T22 strains varying in only a single nucleotide. Probes designed for two strains uniquely recognized the respective strains in Q-PCR with a detection limit of 12,5ng DNA. Titration assays in which T. harzianum DNA from distinct strains was varied further underscored the specificity of the probes. Lastly, fungal DNA extracted from roots of greenhouse cultured tomato plants was analyzed using the probe-based assay. DNA from T. harzianum strain T22 could readily be identified on roots of greenhouse reared tomato plants inoculated with varying concentrations up to one week after treatment with a detection limit of 3e6 colony forming units of T. harzianum T22. We conclude that the Q-PCR method is a reliable and robust method for assessing the presence and quantity of T. harzianum strain T22 in manually inoculated plant material. Our method provides scope for the development of DNA based strain specific identification of additional strains of Trichoderma and other fungal biological control agents.
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Affiliation(s)
- Ivo R Horn
- University of Applied Sciences Leiden, Zernikedreef 11, 2333, CK, Leiden, The Netherlands
| | - Menno van Rijn
- Koppert Biological Systems, Veilingweg 14, 2651, BE, Berkel en Rodenrijs, The Netherlands
| | - Tom J J Zwetsloot
- University of Applied Sciences Leiden, Zernikedreef 11, 2333, CK, Leiden, The Netherlands
| | - Said Basmagi
- University of Applied Sciences Leiden, Zernikedreef 11, 2333, CK, Leiden, The Netherlands
| | - Anita Dirks-Mulder
- University of Applied Sciences Leiden, Zernikedreef 11, 2333, CK, Leiden, The Netherlands
| | - Willem B van Leeuwen
- University of Applied Sciences Leiden, Zernikedreef 11, 2333, CK, Leiden, The Netherlands
| | - Willem J Ravensberg
- Koppert Biological Systems, Veilingweg 14, 2651, BE, Berkel en Rodenrijs, The Netherlands
| | - Barbara Gravendeel
- University of Applied Sciences Leiden, Zernikedreef 11, 2333, CK, Leiden, The Netherlands; Naturalis Biodiversity Center, Darwinweg 2, 2333, CR Leiden, The Netherlands; Institute Biology Leiden, Leiden University, Sylviusweg 72, 2333, BE, Leiden, The Netherlands.
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Rogov AG, Zvyagilskaya RA. Physiological role of alternative oxidase (from yeasts to plants). BIOCHEMISTRY (MOSCOW) 2016; 80:400-7. [PMID: 25869356 DOI: 10.1134/s0006297915040021] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Mitochondria of all so far studied organisms, with the exception of Archaea, mammals, some yeasts, and protists, contain, along with the classical phosphorylating cytochrome pathway, a so-called cyanide-insensitive alternative oxidase (AOX) localized on the matrix side of the mitochondrial inner membrane, and electron transport through which is not coupled with ATP synthesis and energy accumulation. Mechanisms underlying plentiful functions of AOX in organisms at various levels of organization ranging from yeasts to plants are considered. First and foremost, AOX provides a chance of cell survival after inhibiting the terminal components of the main respiratory chain or losing the ability to synthesize these components. The vitally important role of AOX is obvious in thermogenesis of thermogenic plant organs where it becomes the only terminal oxidase with a very high activity, and the energy of substrate oxidation by this respiratory pathway is converted into heat, thus promoting evaporation of volatile substances attracting pollinating insects. AOX plays a fundamentally significant role in alleviating or preventing oxidative stress, thus ensuring the defense against a wide range of stresses and adverse environmental conditions, such as changes in temperature and light intensities, osmotic stress, drought, and attack by incompatible strains of bacterial pathogens, phytopathogens, or their elicitors. Participation of AOX in pathogen survival during its existence inside the host, in antivirus defense, as well as in metabolic rearrangements in plants during embryogenesis and cell differentiation is described. Examples are given to demonstrate that AOX might be an important tool to overcome the adverse aftereffects of restricted activity of the main respiratory chain in cells and whole animals.
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Affiliation(s)
- A G Rogov
- Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow, 119071, Russia.
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Campos C, Cardoso H, Nogales A, Svensson J, Lopez-Ráez JA, Pozo MJ, Nobre T, Schneider C, Arnholdt-Schmitt B. Intra and Inter-Spore Variability in Rhizophagus irregularis AOX Gene. PLoS One 2015; 10:e0142339. [PMID: 26540237 PMCID: PMC4634980 DOI: 10.1371/journal.pone.0142339] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 10/20/2015] [Indexed: 12/03/2022] Open
Abstract
Arbuscular mycorrhizal fungi (AMF) are root-inhabiting fungi that form mutualistic symbioses with their host plants. AMF symbiosis improves nutrient uptake and buffers the plant against a diversity of stresses. Rhizophagus irregularis is one of the most widespread AMF species in the world, and its application in agricultural systems for yield improvement has increased over the last years. Still, from the inoculum production perspective, a lack of consistency of inoculum quality is referred to, which partially may be due to a high genetic variability of the fungus. The alternative oxidase (AOX) is an enzyme of the alternative respiratory chain already described in different taxa, including various fungi, which decreases the damage caused by oxidative stress. Nevertheless, virtually nothing is known on the involvement of AMF AOX on symbiosis establishment, as well on the existence of AOX variability that could affect AMF effectiveness and consequently plant performance. Here, we report the isolation and characterisation of the AOX gene of R. irregularis (RiAOX), and show that it is highly expressed during early phases of the symbiosis with plant roots. Phylogenetic analysis clustered RiAOX sequence with ancient fungi, and multiple sequence alignment revealed the lack of several regulatory motifs which are present in plant AOX. The analysis of RiAOX polymorphisms in single spores of three different isolates showed a reduced variability in one spore relatively to a group of spores. A high number of polymorphisms occurred in introns; nevertheless, some putative amino acid changes resulting from non-synonymous variants were found, offering a basis for selective pressure to occur within the populations. Given the AOX relatedness with stress responses, differences in gene variants amongst R. irregularis isolates are likely to be related with its origin and environmental constraints and might have a potential impact on inoculum production.
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Affiliation(s)
- Catarina Campos
- EU Marie Curie Chair, ICAAM—Instituto de Ciências Agrárias e Ambientais Mediterrânicas, IIFA-Instituto de Formação e Investigação Avançada, Universidade de Évora, Núcleo da Mitra, Évora, Portugal
| | - Hélia Cardoso
- EU Marie Curie Chair, ICAAM—Instituto de Ciências Agrárias e Ambientais Mediterrânicas, IIFA-Instituto de Formação e Investigação Avançada, Universidade de Évora, Núcleo da Mitra, Évora, Portugal
| | - Amaia Nogales
- EU Marie Curie Chair, ICAAM—Instituto de Ciências Agrárias e Ambientais Mediterrânicas, IIFA-Instituto de Formação e Investigação Avançada, Universidade de Évora, Núcleo da Mitra, Évora, Portugal
| | | | - Juan Antonio Lopez-Ráez
- Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas (EEZ-CSIC), Granada, Spain
| | - María José Pozo
- Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas (EEZ-CSIC), Granada, Spain
| | - Tânia Nobre
- EU Marie Curie Chair, ICAAM—Instituto de Ciências Agrárias e Ambientais Mediterrânicas, IIFA-Instituto de Formação e Investigação Avançada, Universidade de Évora, Núcleo da Mitra, Évora, Portugal
| | | | - Birgit Arnholdt-Schmitt
- EU Marie Curie Chair, ICAAM—Instituto de Ciências Agrárias e Ambientais Mediterrânicas, IIFA-Instituto de Formação e Investigação Avançada, Universidade de Évora, Núcleo da Mitra, Évora, Portugal
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Abstract
Enzymes play key roles in fungal pathogenesis. Manipulation of enzyme expression or activity can significantly alter the infection process, and enzyme expression profiles can be a hallmark of disease. Hence, enzymes are worthy targets for better understanding pathogenesis and identifying new options for combatting fungal infections. Advances in genomics, proteomics, transcriptomics, and mass spectrometry have enabled the identification and characterization of new fungal enzymes. This review focuses on recent developments in the virulence-associated enzymes from Cryptococcus neoformans. The enzymatic suite of C. neoformans has evolved for environmental survival, but several of these enzymes play a dual role in colonizing the mammalian host. We also discuss new therapeutic and diagnostic strategies that could be based on the underlying enzymology.
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Rogov AG, Sukhanova EI, Uralskaya LA, Aliverdieva DA, Zvyagilskaya RA. Alternative oxidase: distribution, induction, properties, structure, regulation, and functions. BIOCHEMISTRY (MOSCOW) 2015; 79:1615-34. [PMID: 25749168 DOI: 10.1134/s0006297914130112] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The respiratory chain in the majority of organisms with aerobic type metabolism features the concomitant existence of the phosphorylating cytochrome pathway and the cyanide- and antimycin A-insensitive oxidative route comprising a so-called alternative oxidase (AOX) as a terminal oxidase. In this review, the history of AOX discovery is described. Considerable evidence is presented that AOX occurs widely in organisms at various levels of organization and is not confined to the plant kingdom. This enzyme has not been found only in Archaea, mammals, some yeasts and protists. Bioinformatics research revealed the sequences characteristic of AOX in representatives of various taxonomic groups. Based on multiple alignments of these sequences, a phylogenetic tree was constructed to infer their possible evolution. The ways of AOX activation, as well as regulatory interactions between AOX and the main respiratory chain are described. Data are summarized concerning the properties of AOX and the AOX-encoding genes whose expression is either constitutive or induced by various factors. Information is presented on the structure of AOX, its active center, and the ubiquinone-binding site. The principal functions of AOX are analyzed, including the cases of cell survival, optimization of respiratory metabolism, protection against excess of reactive oxygen species, and adaptation to variable nutrition sources and to biotic and abiotic stress factors. It is emphasized that different AOX functions complement each other in many instances and are not mutually exclusive. Examples are given to demonstrate that AOX is an important tool to overcome the adverse aftereffects of restricted activity of the main respiratory chain in cells and whole animals. This is the first comprehensive review on alternative oxidases of various organisms ranging from yeasts and protists to vascular plants.
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Affiliation(s)
- A G Rogov
- Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow, 119071, Russia.
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Tavares AH, Fernandes L, Bocca AL, Silva-Pereira I, Felipe MS. Transcriptomic reprogramming of genus Paracoccidioides in dimorphism and host niches. Fungal Genet Biol 2015; 81:98-109. [DOI: 10.1016/j.fgb.2014.01.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 01/27/2014] [Accepted: 01/31/2014] [Indexed: 01/04/2023]
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Zhou G, Song Z, Yin Y, Jiang W, Wang Z. Involvement of an alternative oxidase in the regulation of hyphal growth and microsclerotial formation in Nomuraea rileyi CQNr01. World J Microbiol Biotechnol 2015; 31:1343-52. [PMID: 26135515 DOI: 10.1007/s11274-015-1877-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 05/20/2015] [Indexed: 12/01/2022]
Abstract
Mitochondria of Nomuraea rileyi contain an alternative oxidase (Aox), which reduces oxygen to water by accepting electrons directly from ubiquinol. Furthermore, through a transcriptional analysis, we found that an alternative oxidase (Nraox) was up-regulated during microsclerotial formation. To study the function of NrAox, Nraox was cloned from N. rileyi CQNr01. The full-length cDNA was 1266 bp with an open reading frame of 1068 bp encoding 355 amino acids. A phylogenetic analysis revealed that the NrAox of N. rileyi was closely related to Metarhizium acridum Aox. The relative expression level of the Nraox was up-regulated during microsclerotial (MS) initiation. A salicylhydroxamic acid, a specific alternative oxidase inhibitor, application to the culture media severely decreased MS yields, changed the hyphae morphology and slowed the H2O2 removal. Nraox silencing caused mycelial deformations, reduced the MS yields by 97.3 % and increased MS size compared with those of the control. MS virulence was decreased to 26.2 % after Nraox was silenced. However, the Nraox-silenced strain was sensitive to environmental stress, and the growth rate was reduced under stress conditions. The results obtained suggested that Nraox is required for MS differentiation by regulating the intracellular H2O2 concentration and hypha growth. Additionally, Nraox had a great impact on the virulence of N. rileyi.
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Affiliation(s)
- Guilin Zhou
- Chongqing Engineering Research Center for Fungal Insecticides, School of Life Science, Chongqing University, Chongqing, 400030, China
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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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Kwon-Chung KJ, Fraser JA, Doering TL, Wang Z, Janbon G, Idnurm A, Bahn YS. Cryptococcus neoformans and Cryptococcus gattii, the etiologic agents of cryptococcosis. Cold Spring Harb Perspect Med 2014; 4:a019760. [PMID: 24985132 PMCID: PMC4066639 DOI: 10.1101/cshperspect.a019760] [Citation(s) in RCA: 312] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Cryptococcus neoformans and Cryptococcus gattii are the two etiologic agents of cryptococcosis. They belong to the phylum Basidiomycota and can be readily distinguished from other pathogenic yeasts such as Candida by the presence of a polysaccharide capsule, formation of melanin, and urease activity, which all function as virulence determinants. Infection proceeds via inhalation and subsequent dissemination to the central nervous system to cause meningoencephalitis. The most common risk for cryptococcosis caused by C. neoformans is AIDS, whereas infections caused by C. gattii are more often reported in immunocompetent patients with undefined risk than in the immunocompromised. There have been many chapters, reviews, and books written on C. neoformans. The topics we focus on in this article include species description, pathogenesis, life cycle, capsule, and stress response, which serve to highlight the specializations in virulence that have occurred in this unique encapsulated melanin-forming yeast that causes global deaths estimated at more than 600,000 annually.
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Affiliation(s)
- Kyung J Kwon-Chung
- Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892
| | - James A Fraser
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Tamara L Doering
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Zhou Wang
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Guilhem Janbon
- Unité Biologie et Pathogénicité Fongiques, Institut Pasteur, 75015 Paris, France
| | - Alexander Idnurm
- Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri, Kansas City, Missouri 64110
| | - Yong-Sun Bahn
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea
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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] [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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Bloom ALM, Panepinto JC. RNA biology and the adaptation of Cryptococcus neoformans to host temperature and stress. WILEY INTERDISCIPLINARY REVIEWS-RNA 2014; 5:393-406. [PMID: 24497369 DOI: 10.1002/wrna.1219] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 12/06/2013] [Accepted: 12/20/2013] [Indexed: 01/26/2023]
Abstract
Cryptococcus neoformans is an environmental fungus that can cause severe disease in humans. C. neoformans encounters a multitude of stresses within the human host to which it must adapt in order to survive and proliferate. Upon stressful changes in the external milieu, C. neoformans must reprogram its gene expression to properly respond to and combat stress in order to maintain homeostasis. Several studies have investigated the changes that occur in response to these stresses to begin to unravel the mechanisms of adaptation in this organism. Here, we review studies that have explored stress-induced changes in gene expression with a focus on host temperature adaptation. We compare global messenger RNA (mRNA) expression data compiled from several studies and identify patterns that suggest that orchestrated, transient responses occur. We also utilize the available expression data to explore the possibility of a common stress response that may contribute to cellular protection against a variety of stresses in C. neoformans. In addition, we review studies that have revealed the significance of post-transcriptional mechanisms of mRNA regulation in response to stress, and discuss how these processes may contribute to adaptation and virulence.
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Affiliation(s)
- Amanda L M Bloom
- Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, the State University of New York, Buffalo, NY, USA
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Genetic and functional investigation of Zn(2)Cys(6) transcription factors RSE2 and RSE3 in Podospora anserina. EUKARYOTIC CELL 2013; 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] [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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Xu T, Wang YT, Liang WS, Yao F, Li YH, Li DR, Wang H, Wang ZY. Involvement of alternative oxidase in the regulation of sensitivity of Sclerotinia sclerotiorum to the fungicides azoxystrobin and procymidone. J Microbiol 2013; 51:352-8. [DOI: 10.1007/s12275-013-2534-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 01/17/2013] [Indexed: 11/30/2022]
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Redundant catalases detoxify phagocyte reactive oxygen and facilitate Histoplasma capsulatum pathogenesis. Infect Immun 2013; 81:2334-46. [PMID: 23589579 DOI: 10.1128/iai.00173-13] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Histoplasma capsulatum is a respiratory pathogen that infects phagocytic cells. The mechanisms allowing Histoplasma to overcome toxic reactive oxygen molecules produced by the innate immune system are an integral part of Histoplasma's ability to survive during infection. To probe the contribution of Histoplasma catalases in oxidative stress defense, we created and analyzed the virulence defects of mutants lacking CatB and CatP, which are responsible for extracellular and intracellular catalase activities, respectively. Both CatB and CatP protected Histoplasma from peroxide challenge in vitro and from antimicrobial reactive oxygen produced by human neutrophils and activated macrophages. Optimal protection required both catalases, as the survival of a double mutant lacking both CatB and CatP was lower than that of single-catalase-deficient cells. Although CatB contributed to reactive oxygen species defenses in vitro, CatB was dispensable for lung infection and extrapulmonary dissemination in vivo. Loss of CatB from a strain also lacking superoxide dismutase (Sod3) did not further reduce the survival of Histoplasma yeasts. Nevertheless, some catalase function was required for pathogenesis since simultaneous loss of both CatB and CatP attenuated Histoplasma virulence in vivo. These results demonstrate that Histoplasma's dual catalases comprise a system that enables Histoplasma to efficiently overcome the reactive oxygen produced by the innate immune system.
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