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Interconnected Set of Enzymes Provide Lysine Biosynthetic Intermediates and Ornithine Derivatives as Key Precursors for the Biosynthesis of Bioactive Secondary Metabolites. Antibiotics (Basel) 2023; 12:antibiotics12010159. [PMID: 36671360 PMCID: PMC9854754 DOI: 10.3390/antibiotics12010159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/08/2023] [Accepted: 01/09/2023] [Indexed: 01/15/2023] Open
Abstract
Bacteria, filamentous fungi, and plants synthesize thousands of secondary metabolites with important biological and pharmacological activities. The biosynthesis of these metabolites is performed by networks of complex enzymes such as non-ribosomal peptide synthetases, polyketide synthases, and terpenoid biosynthetic enzymes. The efficient production of these metabolites is dependent upon the supply of precursors that arise from primary metabolism. In the last decades, an impressive array of biosynthetic enzymes that provide specific precursors and intermediates leading to secondary metabolites biosynthesis has been reported. Suitable knowledge of the elaborated pathways that synthesize these precursors or intermediates is essential for advancing chemical biology and the production of natural or semisynthetic biological products. Two of the more prolific routes that provide key precursors in the biosynthesis of antitumor, immunosuppressant, antifungal, or antibacterial compounds are the lysine and ornithine pathways, which are involved in the biosynthesis of β-lactams and other non-ribosomal peptides, and bacterial and fungal siderophores. Detailed analysis of the molecular genetics and biochemistry of the enzyme system shows that they are formed by closely related components. Particularly the focus of this study is on molecular genetics and the enzymatic steps that lead to the formation of intermediates of the lysine pathway, such as α-aminoadipic acid, saccharopine, pipecolic acid, and related compounds, and of ornithine-derived molecules, such as N5-Acetyl-N5-Hydroxyornithine and N5-anhydromevalonyl-N5-hydroxyornithine, which are precursors of siderophores. We provide evidence that shows interesting functional relationships between the genes encoding the enzymes that synthesize these products. This information will contribute to a better understanding of the possibilities of advancing the industrial applications of synthetic biology.
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2
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Siesto G, Corbo MR, Pietrafesa R, Sinigaglia M, Romano P, Bevilacqua A. Screening of Saccharomyces and Non- Saccharomyces Wine Yeasts for Their Decarboxylase Activity of Amino Acids. Foods 2022; 11:foods11223587. [PMID: 36429178 PMCID: PMC9689846 DOI: 10.3390/foods11223587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/06/2022] [Accepted: 11/09/2022] [Indexed: 11/16/2022] Open
Abstract
The type and quantity of precursor amino acids present in grape must that are used by wine yeasts affect the organoleptic and health properties of wine. The aim of this work was to conduct a preliminary screening among Saccharomyces and non-Saccharomyces indigenous strains, which were previously isolated from different Italian regional grape varieties. This was performed in order to evaluate their decarboxylase activity on certain important amino acids-such as arginine, proline, serine, and tyrosine-that are present in grape must. In particular, a qualitative test on 122 wine yeasts was performed on a decarboxylase medium using arginine, proline, serine, and tyrosine as precursor amino acids. Our results showed a considerable variability among the microbial species tested for this parameter. Indeed, Saccharomyces cerevisiae strains exhibited a high decarboxylase capability of the four amino acids tested; moreover, only 10% of the total (i.e., a total of 81) did not show this trait. A high recovery of decarboxylation ability for at least one amino acid was also found for Zygosaccharomyces bailii and Hanseniaspora spp. These findings can, therefore, promote the inclusion of decarboxylase activity as an additional characteristic in a wine yeast selection program in order to choose starter cultures that possess desirable technological traits; moreover, this also can contribute to the safeguarding of consumer health.
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Affiliation(s)
- Gabriella Siesto
- School of Agricultural, Forestry, Food and Environmental Sciences, University of Basilicata, Via dell’Ateneo Lucano 10, 85100 Potenza, Italy
| | - Maria Rosaria Corbo
- Department of Agriculture, Food, Natural Resources, and Engineering, University of Foggia, 71122 Foggia, Italy
| | - Rocchina Pietrafesa
- School of Agricultural, Forestry, Food and Environmental Sciences, University of Basilicata, Via dell’Ateneo Lucano 10, 85100 Potenza, Italy
| | - Milena Sinigaglia
- Department of Agriculture, Food, Natural Resources, and Engineering, University of Foggia, 71122 Foggia, Italy
| | - Patrizia Romano
- Faculty of Economy, Universitas Mercatorum, Piazza Mattei, 10, 00186 Rome, Italy
- Correspondence: (P.R.); (A.B.)
| | - Antonio Bevilacqua
- Department of Agriculture, Food, Natural Resources, and Engineering, University of Foggia, 71122 Foggia, Italy
- Correspondence: (P.R.); (A.B.)
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3
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Were E, Schöne J, Viljoen A, Rasche F. De novo synthesis of ferrichrome by Fusarium oxysporum f. sp. cubense TR4 in response to iron starvation. Fungal Biol 2022; 126:521-527. [DOI: 10.1016/j.funbio.2022.05.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 05/03/2022] [Accepted: 05/24/2022] [Indexed: 11/04/2022]
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4
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Pfister J, Petrik M, Bendova K, Matuszczak B, Binder U, Misslinger M, Kühbacher A, Gsaller F, Haas H, Decristoforo C. Antifungal Siderophore Conjugates for Theranostic Applications in Invasive Pulmonary Aspergillosis Using Low-Molecular TAFC Scaffolds. J Fungi (Basel) 2021; 7:558. [PMID: 34356941 PMCID: PMC8304796 DOI: 10.3390/jof7070558] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/08/2021] [Accepted: 07/12/2021] [Indexed: 12/14/2022] Open
Abstract
Invasive pulmonary aspergillosis (IPA) is a life-threatening form of fungal infection, primarily in immunocompromised patients and associated with significant mortality. Diagnostic procedures are often invasive and/or time consuming and existing antifungals can be constrained by dose-limiting toxicity and drug interaction. In this study, we modified triacetylfusarinine C (TAFC), the main siderophore produced by the opportunistic pathogen Aspergillus fumigatus (A. fumigatus), with antifungal molecules to perform antifungal susceptibility tests and molecular imaging. A variation of small organic molecules (eflornithine, fludioxonil, thiomersal, fluoroorotic acid (FOA), cyanine 5 (Cy5) with antifungal activity were coupled to diacetylfusarinine C (DAFC), resulting in a "Trojan horse" to deliver antifungal compounds specifically into A. fumigatus hyphae by the major facilitator transporter MirB. Radioactive labeling with gallium-68 allowed us to perform in vitro characterization (distribution coefficient, stability, uptake assay) as well as biodistribution experiments and PET/CT imaging in an IPA rat infection model. Compounds chelated with stable gallium were used for antifungal susceptibility tests. [Ga]DAFC-fludioxonil, -FOA, and -Cy5 revealed a MirB-dependent active uptake with fungal growth inhibition at 16 µg/mL after 24 h. Visualization of an A. fumigatus infection in lungs of a rat was possible with gallium-68-labeled compounds using PET/CT. Heterogeneous biodistribution patterns revealed the immense influence of the antifungal moiety conjugated to DAFC. Overall, novel antifungal siderophore conjugates with promising fungal growth inhibition and the possibility to perform PET imaging combine both therapeutic and diagnostic potential in a theranostic compound for IPA caused by A. fumigatus.
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Affiliation(s)
- Joachim Pfister
- Department of Nuclear Medicine, Medical University Innsbruck, A-6020 Innsbruck, Austria;
| | - Milos Petrik
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University Olomouc, 77200 Olomouc, Czech Republic; (M.P.); (K.B.)
| | - Katerina Bendova
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University Olomouc, 77200 Olomouc, Czech Republic; (M.P.); (K.B.)
| | - Barbara Matuszczak
- Institute of Pharmacy/Pharmaceutical Chemistry, University of Innsbruck, A-6020 Innsbruck, Austria;
| | - Ulrike Binder
- Institute of Hygiene & Medical Microbiology, Medical University of Innsbruck, A-6020 Innsbruck, Austria;
| | - Matthias Misslinger
- Institute of Molecular Biology, Medical University of Innsbruck, A-6020 Innsbruck, Austria; (M.M.); (A.K.); (F.G.); (H.H.)
| | - Alexander Kühbacher
- Institute of Molecular Biology, Medical University of Innsbruck, A-6020 Innsbruck, Austria; (M.M.); (A.K.); (F.G.); (H.H.)
| | - Fabio Gsaller
- Institute of Molecular Biology, Medical University of Innsbruck, A-6020 Innsbruck, Austria; (M.M.); (A.K.); (F.G.); (H.H.)
| | - Hubertus Haas
- Institute of Molecular Biology, Medical University of Innsbruck, A-6020 Innsbruck, Austria; (M.M.); (A.K.); (F.G.); (H.H.)
| | - Clemens Decristoforo
- Department of Nuclear Medicine, Medical University Innsbruck, A-6020 Innsbruck, Austria;
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5
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Kong C, Wang Z, Liu G, Chi Z, Ledesma‐Amaro R, Chi Z. Bioproduction of L-piperazic acid in gram scale using Aureobasidium melanogenum. Microb Biotechnol 2021; 14:1722-1729. [PMID: 34081404 PMCID: PMC8313269 DOI: 10.1111/1751-7915.13838] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 05/08/2021] [Accepted: 05/11/2021] [Indexed: 11/29/2022] Open
Abstract
Currently, piperazic acid is chemically synthesized using ecologically unfriendly processes. Microbial synthesis from glucose is an attractive alternative to chemical synthesis. In this study, we report the production of L-piperazic acid via microbial fermentation with the first engineered fungal strain of Aureobasidium melanogenum; this strain was constructed by chassis development, genetic element reconstitution and optimization, synthetic rewiring and constitutive genetic circuit reconstitution, to build a robust L-piperazic acid synthetic cascade. These genetic modifications enable A. melanogenum to directly convert glucose to L-piperazic acid without relying on the use of either chemically synthesized precursors or harsh conditions. This bio-based process overcomes the shortcomings of the conventional synthesis routes. The ultimately engineered strain is a very high-efficient cell factory that can excrete 1.12 ± 0.05 g l-1 of L-piperazic acid after a 120-h 10.0-l fed-batch fermentation; this is the highest titre of L-piperazic acid reported using a microbial cell factory.
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Affiliation(s)
- Cuncui Kong
- College of Marine Life SciencesOcean University of ChinaNo.5 Yushan RoadQingdao266003China
| | - Zhuangzhuang Wang
- College of Marine Life SciencesOcean University of ChinaNo.5 Yushan RoadQingdao266003China
| | - Guanglei Liu
- College of Marine Life SciencesOcean University of ChinaNo.5 Yushan RoadQingdao266003China
- Pilot National Laboratory for Marine Science and TechnologyNo.1 Wenhai RoadQingdao266237China
| | - Zhenming Chi
- College of Marine Life SciencesOcean University of ChinaNo.5 Yushan RoadQingdao266003China
- Pilot National Laboratory for Marine Science and TechnologyNo.1 Wenhai RoadQingdao266237China
| | | | - Zhe Chi
- College of Marine Life SciencesOcean University of ChinaNo.5 Yushan RoadQingdao266003China
- Pilot National Laboratory for Marine Science and TechnologyNo.1 Wenhai RoadQingdao266237China
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6
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Nitrogen, Iron and Zinc Acquisition: Key Nutrients to Aspergillus fumigatus Virulence. J Fungi (Basel) 2021; 7:jof7070518. [PMID: 34203370 PMCID: PMC8303583 DOI: 10.3390/jof7070518] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 06/24/2021] [Accepted: 06/24/2021] [Indexed: 12/31/2022] Open
Abstract
Aspergillus fumigatus is a ubiquitous soil decomposer and an opportunistic pathogen that is characterized by its large metabolic machinery for acquiring nutrients from media. Lately, an ever-increasing number of genes involved in fungal nutrition has been associated with its virulence. Of these, nitrogen, iron, and zinc metabolism-related genes are particularly noteworthy, since 78% of them have a direct implication in virulence. In this review, we describe the sensing, uptake and regulation process of the acquisition of these nutrients, the connections between pathways and the virulence-implicated genes. Nevertheless, only 40% of the genes mentioned in this review have been assayed for roles in virulence, leaving a wide field of knowledge that remains uncertain and might offer new therapeutic and diagnostic targets.
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7
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Durieux MF, Melloul É, Jemel S, Roisin L, Dardé ML, Guillot J, Dannaoui É, Botterel F. Galleria mellonella as a screening tool to study virulence factors of Aspergillus fumigatus. Virulence 2021; 12:818-834. [PMID: 33682618 PMCID: PMC7946008 DOI: 10.1080/21505594.2021.1893945] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
The invertebrate Galleria mellonella has increasingly and widely been used in the last few years to study complex host–microbe interactions. Aspergillus fumigatus is one of the most pathogenic fungi causing life-threatening diseases in humans and animals. Galleria mellonella larvae has been proven as a reliable model for the analysis of pathogenesis and virulence factors, enable to screen a large number of A. fumigatus strains. This review describes the different uses of G. mellonella to study A. fumigatus and provides a comparison of the different protocols to trace fungal pathogenicity. The review also includes a summary of the diverse mutants tested in G. mellonella, and their respective contribution to A. fumigatus virulence. Previous investigations indicated that G. mellonella should be considered as an interesting tool even though a mammalian model may be required to complete and verify initial data.
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Affiliation(s)
- Marie-Fleur Durieux
- Laboratoire de Parasitologie - Mycologie, CHU de Limoges, Limoges, France.,EA 7380 Dynamic, Université Paris Est Créteil, EnvA, USC ANSES, Créteil, France
| | - Élise Melloul
- EA 7380 Dynamic, Université Paris Est Créteil, EnvA, USC ANSES, Créteil, France
| | - Sana Jemel
- EA 7380 Dynamic, Université Paris Est Créteil, EnvA, USC ANSES, Créteil, France
| | - Lolita Roisin
- EA 7380 Dynamic, Université Paris Est Créteil, EnvA, USC ANSES, Créteil, France
| | - Marie-Laure Dardé
- Laboratoire de Parasitologie - Mycologie, CHU de Limoges, Limoges, France
| | - Jacques Guillot
- EA 7380 Dynamic, Université Paris Est Créteil, EnvA, USC ANSES, Créteil, France.,École Nationale Vétérinaire d'Alfort, Maisons-Alfort, France
| | - Éric Dannaoui
- EA 7380 Dynamic, Université Paris Est Créteil, EnvA, USC ANSES, Créteil, France.,Unité de Parasitologie-mycologie, Service de Microbiologie, Université Paris Descartes, Hôpital Européen Georges Pompidou, AP-HP, Paris, France
| | - Françoise Botterel
- EA 7380 Dynamic, Université Paris Est Créteil, EnvA, USC ANSES, Créteil, France.,Unité de Mycologie, Département de Prévention, Diagnostic Et Traitement Des Infections, Groupe Hospitalier Henri Mondor - Albert Chenevier, APHP, France
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8
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Chen M, Zhong G, Wang S, Zhu J, Tang L, Li L. tpo3 and dur3, Aspergillus fumigatus Plasma Membrane Regulators of Polyamines, Regulate Polyamine Homeostasis and Susceptibility to Itraconazole. Front Microbiol 2021; 11:563139. [PMID: 33391196 PMCID: PMC7772357 DOI: 10.3389/fmicb.2020.563139] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 11/25/2020] [Indexed: 11/13/2022] Open
Abstract
Aspergillus fumigatus is a well-known opportunistic pathogen that causes invasive aspergillosis (IA) infections, which have high mortality rates in immunosuppressed individuals. Long-term antifungal drug azole use in clinical treatment and agriculture results in loss of efficacy or drug resistance. Drug resistance is related to cellular metabolites and the corresponding gene transcription. In this study, through untargeted metabolomics and transcriptomics under itraconazole (ITC) treatment, we identified two plasma membrane-localized polyamine regulators tpo3 and dur3, which were important for polyamine homeostasis and susceptibility to ITC in A. fumigatus. In the absence of tpo3 and/or dur3, the levels of cytoplasmic polyamines had a moderate increase, which enhanced the tolerance of A. fumigatus to ITC. In comparison, overexpression of tpo3 or dur3 induced a drastic increase in polyamines, which increased the sensitivity of A. fumigatus to ITC. Further analysis revealed that polyamines concentration-dependently affected the susceptibility of A. fumigatus to ITC by scavenging reactive oxygen species (ROS) at a moderate concentration and promoting the production of ROS at a high concentration rather than regulating drug transport. Moreover, inhibition of polyamine biosynthesis reduced the intracellular polyamine content, resulted in accumulation of ROS and enhanced the antifungal activity of ITC. Interestingly, A. fumigatus produces much lower levels of ROS under voriconazole (VOC) treatment than under ITC-treatment. Accordingly, our study established the link among the polyamine regulators tpo3 and dur3, polyamine homeostasis, ROS content, and ITC susceptibility in A. fumigatus.
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Affiliation(s)
- Mingcong Chen
- Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Guowei Zhong
- Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Sha Wang
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, Huzhou Central Hospital, Huzhou University, Huzhou, China
| | - Jun Zhu
- Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Lei Tang
- Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Lei Li
- Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
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9
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Stanford FA, Voigt K. Iron Assimilation during Emerging Infections Caused by Opportunistic Fungi with emphasis on Mucorales and the Development of Antifungal Resistance. Genes (Basel) 2020; 11:genes11111296. [PMID: 33143139 PMCID: PMC7693903 DOI: 10.3390/genes11111296] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 10/23/2020] [Accepted: 10/28/2020] [Indexed: 02/06/2023] Open
Abstract
Iron is a key transition metal required by most microorganisms and is prominently utilised in the transfer of electrons during metabolic reactions. The acquisition of iron is essential and becomes a crucial pathogenic event for opportunistic fungi. Iron is not readily available in the natural environment as it exists in its insoluble ferric form, i.e., in oxides and hydroxides. During infection, the host iron is bound to proteins such as transferrin, ferritin, and haemoglobin. As such, access to iron is one of the major hurdles that fungal pathogens must overcome in an immunocompromised host. Thus, these opportunistic fungi utilise three major iron acquisition systems to overcome this limiting factor for growth and proliferation. To date, numerous iron acquisition pathways have been fully characterised, with key components of these systems having major roles in virulence. Most recently, proteins involved in these pathways have been linked to the development of antifungal resistance. Here, we provide a detailed review of our current knowledge of iron acquisition in opportunistic fungi, and the role iron may have on the development of resistance to antifungals with emphasis on species of the fungal basal lineage order Mucorales, the causative agents of mucormycosis.
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Affiliation(s)
- Felicia Adelina Stanford
- Jena Microbial Resource Collection, Leibniz Institute for Natural Product Research, and Infection Biology–Hans Knöll Institute, Jena, Adolf-Reichwein-Straße 23, 07745 Jena, Germany;
- Institute of Microbiology, Faculty of Biological Sciences, Friedrich-Schiller University Jena, Neugasse 25, 07743 Jena, Germany
| | - Kerstin Voigt
- Jena Microbial Resource Collection, Leibniz Institute for Natural Product Research, and Infection Biology–Hans Knöll Institute, Jena, Adolf-Reichwein-Straße 23, 07745 Jena, Germany;
- Institute of Microbiology, Faculty of Biological Sciences, Friedrich-Schiller University Jena, Neugasse 25, 07743 Jena, Germany
- Leibniz Institute for Natural Product Research and Infection Biology–Hans Knöll Institute, Jena Microbial Resource Collection Adolf-Reichwein-Straße 23, 07745 Jena, Germany
- Correspondence: ; Tel.: +49-3641-532-1395; Fax: +49-3641-532-2395
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10
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Misslinger M, Hortschansky P, Brakhage AA, Haas H. Fungal iron homeostasis with a focus on Aspergillus fumigatus. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1868:118885. [PMID: 33045305 DOI: 10.1016/j.bbamcr.2020.118885] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/15/2020] [Accepted: 10/01/2020] [Indexed: 02/08/2023]
Abstract
To maintain iron homeostasis, fungi have to balance iron acquisition, storage, and utilization to ensure sufficient supply and to avoid toxic excess of this essential trace element. As pathogens usually encounter iron limitation in the host niche, this metal plays a particular role during virulence. Siderophores are iron-chelators synthesized by most, but not all fungal species to sequester iron extra- and intracellularly. In recent years, the facultative human pathogen Aspergillus fumigatus has become a model for fungal iron homeostasis of siderophore-producing fungal species. This article summarizes the knowledge on fungal iron homeostasis and its links to virulence with a focus on A. fumigatus. It covers mechanisms for iron acquisition, storage, and detoxification, as well as the modes of transcriptional iron regulation and iron sensing in A. fumigatus in comparison to other fungal species. Moreover, potential translational applications of the peculiarities of fungal iron metabolism for treatment and diagnosis of fungal infections is addressed.
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Affiliation(s)
- Matthias Misslinger
- Institute of Molecular Biology - Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Peter Hortschansky
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (HKI), Jena, Germany
| | - Axel A Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (HKI), Jena, Germany; Department Microbiology and Molecular Biology, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Hubertus Haas
- Institute of Molecular Biology - Biocenter, Medical University of Innsbruck, Innsbruck, Austria.
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11
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Wang Z, Song Q, Shuai L, Htun R, Malviya MK, Li Y, Liang Q, Zhang G, Zhang M, Zhou F. Metabolic and proteomic analysis of nitrogen metabolism mechanisms involved in the sugarcane - Fusarium verticillioides interaction. JOURNAL OF PLANT PHYSIOLOGY 2020; 251:153207. [PMID: 32593920 DOI: 10.1016/j.jplph.2020.153207] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 05/17/2020] [Accepted: 05/18/2020] [Indexed: 05/18/2023]
Abstract
Pokkah boeng disease (PBD) is a foliar disease causing severe losses in sugarcane crop production. Research into resistance mechanisms against the causal agent, Fusarium verticillioides, is particularly important for farmers and researchers. This work based on the comprehensive analysis of metabolic, proteomic, and bioinformatics data on nitrogen (N) metabolism, which revealed that this biosynthetic reactions was closely related to resistance mechanisms in the sugarcane- F. verticillioides interaction. Our results suggested that pathogen infection reduced the suppression of nitrate reductase (NR) activity, reducing ammonium nitrogen (NH4+-N) and nitrate nitrogen (NO3--N) assimilation, which reduces glutamine synthetase (GS), glutamate synthetase (GOGAT) activity and polynucleotide synthesis and promotes RNA degradation, resulting in a decrease in ribosome levels and protein synthesis. Cysteine was found to be associated with the symptoms of PBD, while alanine, lysine, proline, and glutamic acid were found to be involved in protective and regulatory mechanisms as well. Additionally, glutamate played an important role in sugarcane defense against pathogens through the biosynthesis of proline and polyamines. Cyanamide, glutamate, proline, tyrosine, and arachidonic acid metabolism actively participate in resistance and response to stress. C5XPZ6 and C5XCA6 were considered to be critical proteins and key effectors according to this study. In conclusion, we have identified potential proteins and pathways involved in sugarcane resistance to F. verticillioides, revealing new findings that may be useful in the design of future diagnostics or sugarcane protection strategies and providing new insights into the molecular mechanisms of sugarcane-pathogen interactions.
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Affiliation(s)
- Zeping Wang
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences/Sugarcane Research Center, Chinese Academy of Agricultural Science/Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture. Nanning, 530007, China; College of Agriculture, State Key Laboratory of Conservation and Utilization of Subtropical Agrobioresources, Guangxi University, Nanning, Guangxi, 530004, China.
| | - Qian Song
- Flowers Research Institute, Guangxi Academy of Agricultural Sciences, Nanning, Guangxi, 530007, China
| | - Liang Shuai
- College of Food and Biological Engineering/Institute of Food Research, Hezhou University, Hezhou, 542899, Guangxi, China
| | - Reemon Htun
- Department of Biotechnology, Mandalay Technological University, Mandalay, Myanmar
| | - Mukesh Kumar Malviya
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences/Sugarcane Research Center, Chinese Academy of Agricultural Science/Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture. Nanning, 530007, China
| | - Yijie Li
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences/Sugarcane Research Center, Chinese Academy of Agricultural Science/Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture. Nanning, 530007, China
| | - Qiang Liang
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences/Sugarcane Research Center, Chinese Academy of Agricultural Science/Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture. Nanning, 530007, China
| | - Gemin Zhang
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences/Sugarcane Research Center, Chinese Academy of Agricultural Science/Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture. Nanning, 530007, China
| | - Muqing Zhang
- College of Agriculture, State Key Laboratory of Conservation and Utilization of Subtropical Agrobioresources, Guangxi University, Nanning, Guangxi, 530004, China.
| | - Fengjue Zhou
- College of Agriculture, State Key Laboratory of Conservation and Utilization of Subtropical Agrobioresources, Guangxi University, Nanning, Guangxi, 530004, China.
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12
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Dietl AM, Binder U, Bauer I, Shadkchan Y, Osherov N, Haas H. Arginine Auxotrophy Affects Siderophore Biosynthesis and Attenuates Virulence of Aspergillus fumigatus. Genes (Basel) 2020; 11:genes11040423. [PMID: 32326414 PMCID: PMC7231135 DOI: 10.3390/genes11040423] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 04/09/2020] [Indexed: 12/17/2022] Open
Abstract
Aspergillus fumigatus is an opportunistic human pathogen mainly infecting immunocompromised patients. The aim of this study was to characterize the role of arginine biosynthesis in virulence of A. fumigatus via genetic inactivation of two key arginine biosynthetic enzymes, the bifunctional acetylglutamate synthase/ornithine acetyltransferase (argJ/AFUA_5G08120) and the ornithine carbamoyltransferase (argB/AFUA_4G07190). Arginine biosynthesis is intimately linked to the biosynthesis of ornithine, a precursor for siderophore production that has previously been shown to be essential for virulence in A. fumigatus. ArgJ is of particular interest as it is the only arginine biosynthetic enzyme lacking mammalian homologs. Inactivation of either ArgJ or ArgB resulted in arginine auxotrophy. Lack of ArgJ, which is essential for mitochondrial ornithine biosynthesis, significantly decreased siderophore production during limited arginine supply with glutamine as nitrogen source, but not with arginine as sole nitrogen source. In contrast, siderophore production reached wild-type levels under both growth conditions in ArgB null strains. These data indicate that siderophore biosynthesis is mainly fueled by mitochondrial ornithine production during limited arginine availability, but by cytosolic ornithine production during high arginine availability via cytosolic arginine hydrolysis. Lack of ArgJ or ArgB attenuated virulence of A. fumigatus in the insect model Galleria mellonella and in murine models for invasive aspergillosis, indicating limited arginine availability in the investigated host niches.
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Affiliation(s)
- Anna-Maria Dietl
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (A.-M.D.); (I.B.)
| | - Ulrike Binder
- Institute of Hygiene & Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria;
| | - Ingo Bauer
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (A.-M.D.); (I.B.)
| | - Yana Shadkchan
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, 69978 Tel-Aviv, Israel; (Y.S.); (N.O.)
| | - Nir Osherov
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, 69978 Tel-Aviv, Israel; (Y.S.); (N.O.)
| | - Hubertus Haas
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (A.-M.D.); (I.B.)
- Correspondence:
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Lu Y, Wang H, Wang Z, Cong Y, Zhang P, Liu G, Liu C, Chi Z, Chi Z. Metabolic Rewiring Improves the Production of the Fungal Active Targeting Molecule Fusarinine C. ACS Synth Biol 2019; 8:1755-1765. [PMID: 31268300 DOI: 10.1021/acssynbio.9b00026] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Author: Recently, increasing research in siderophores has been dedicated to their possible medical applications in diagnostics and therapeutics for human pathogenic infections. Fusarinine C (FsC) is a natural hydroxamate siderophore that harbors three amino groups, which allow the easy chemical modification of FsC for the design of novel multifunctional conjugates. However, low production of FsC has hampered its extensive exploitation.Herein, we rewired the FsC biosynthetic pathway in the Aureobasidium melanogenum HN6.2 strain to achieve a self-supplying l-ornithine with component-simplified and enhanced production of extracellular siderophores, for which the FsC accounted for 94%, its final titer being approximately 1.7 g L-1. The convenient acquisition of FsC effectuated our exploitation for its application. We employed in vitro and in vivo assays to show that FsC is an active targeting molecule that acts on the human pathogenic fungi Trichophyton rubrum and Candida albicans; this demonstrates the potential to use FsC for the development of novel antifungal targeting reagents in the future.
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Affiliation(s)
- Yi Lu
- College of Marine Life Sciences, Ocean University of China, No.5 Yushan Road, Qingdao, 266003, China
| | - Hongying Wang
- College of Marine Life Sciences, Ocean University of China, No.5 Yushan Road, Qingdao, 266003, China
| | - Zhuangzhuang Wang
- College of Marine Life Sciences, Ocean University of China, No.5 Yushan Road, Qingdao, 266003, China
| | - Ying Cong
- College of Marine Life Sciences, Ocean University of China, No.5 Yushan Road, Qingdao, 266003, China
| | - Peng Zhang
- Tobacco Research Institute of Chinese Academy of Agricultural Sciences, No.11 Keyuan Jingsi Road, Qingdao, 266001, China
| | - Guanglei Liu
- College of Marine Life Sciences, Ocean University of China, No.5 Yushan Road, Qingdao, 266003, China
| | - Chenguang Liu
- College of Marine Life Sciences, Ocean University of China, No.5 Yushan Road, Qingdao, 266003, China
| | - Zhenming Chi
- College of Marine Life Sciences, Ocean University of China, No.5 Yushan Road, Qingdao, 266003, China
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, No.5 Yushan Road, Qingdao, 266003, China
- Pilot National Laboratory for Marine Science and Technology, No.1 Wenhai Road, Qingdao, 266237, China
| | - Zhe Chi
- College of Marine Life Sciences, Ocean University of China, No.5 Yushan Road, Qingdao, 266003, China
- Pilot National Laboratory for Marine Science and Technology, No.1 Wenhai Road, Qingdao, 266237, China
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Calvillo-Medina RP, Reyes-Grajeda JP, Barba-Escoto L, Bautista-Hernandez LA, Campos-Guillén J, Jones GH, Bautista-de Lucio VM. Proteome analysis of biofilm produced by a Fusarium falciforme keratitis infectious agent. Microb Pathog 2019; 130:232-241. [DOI: 10.1016/j.micpath.2019.03.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 11/30/2018] [Accepted: 03/01/2019] [Indexed: 11/16/2022]
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15
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Chelius CL, Ribeiro LFC, Huso W, Kumar J, Lincoln S, Tran B, Goo YA, Srivastava R, Harris SD, Marten MR. Phosphoproteomic and transcriptomic analyses reveal multiple functions for Aspergillus nidulans MpkA independent of cell wall stress. Fungal Genet Biol 2019; 125:1-12. [PMID: 30639305 DOI: 10.1016/j.fgb.2019.01.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 12/18/2018] [Accepted: 01/04/2019] [Indexed: 12/17/2022]
Abstract
The protein kinase MpkA plays a prominent role in the cell wall integrity signaling (CWIS) pathway, acting as the terminal MAPK activating expression of genes which encode cell wall biosynthetic enzymes and other repair functions. Numerous studies focus on MpkA function during cell wall perturbation. Here, we focus on the role MpkA plays outside of cell wall stress, during steady state growth. In an effort to seek other, as yet unknown, connections to this pathway, an mpkA deletion mutant (ΔmpkA) was subjected to phosphoproteomic and transcriptomic analysis. When compared to the control (isogenic parent of ΔmpkA), there is strong evidence suggesting MpkA is involved with maintaining cell wall strength, branching regulation, and the iron starvation pathway, among others. Particle-size analysis during shake flask growth revealed ΔmpkA mycelia were about 4 times smaller than the control strain and more than 90 cell wall related genes show significantly altered expression levels. The deletion mutant had a significantly higher branching rate than the control and phosphoproteomic results show putative branching-regulation proteins, such as CotA, LagA, and Cdc24, have a significantly different level of phosphorylation. When grown in iron limited conditions, ΔmpkA had no difference in growth rate or production of siderophores, whereas the control strain showed decreased growth rate and increased siderophore production. Transcriptomic data revealed over 25 iron related genes with altered transcript levels. Results suggest MpkA is involved with regulation of broad cellular functions in the absence of stress.
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Affiliation(s)
- Cynthia L Chelius
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, Baltimore, MD 21250, United States
| | - Liliane F C Ribeiro
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, Baltimore, MD 21250, United States
| | - Walker Huso
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, Baltimore, MD 21250, United States
| | - Jyothi Kumar
- Center for Plant Science Innovation and Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE 68588, United States
| | - Stephen Lincoln
- Department of Chemical and Biomolecular Engineering, University of Connecticut, Storrs, CT 06269, United States
| | - Bao Tran
- Mass Spectrometry Center, University of Maryland School of Pharmacy, Baltimore, MD, 21201, United States
| | - Young Ah Goo
- Mass Spectrometry Center, University of Maryland School of Pharmacy, Baltimore, MD, 21201, United States
| | - Ranjan Srivastava
- Department of Chemical and Biomolecular Engineering, University of Connecticut, Storrs, CT 06269, United States
| | - Steven D Harris
- Center for Plant Science Innovation and Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE 68588, United States
| | - Mark R Marten
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, Baltimore, MD 21250, United States.
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Majumdar R, Lebar M, Mack B, Minocha R, Minocha S, Carter-Wientjes C, Sickler C, Rajasekaran K, Cary JW. The Aspergillus flavus Spermidine Synthase ( spds) Gene, Is Required for Normal Development, Aflatoxin Production, and Pathogenesis During Infection of Maize Kernels. FRONTIERS IN PLANT SCIENCE 2018; 9:317. [PMID: 29616053 PMCID: PMC5870473 DOI: 10.3389/fpls.2018.00317] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 02/27/2018] [Indexed: 05/10/2023]
Abstract
Aspergillus flavus is a soil-borne saprophyte and an opportunistic pathogen of both humans and plants. This fungus not only causes disease in important food and feed crops such as maize, peanut, cottonseed, and tree nuts but also produces the toxic and carcinogenic secondary metabolites (SMs) known as aflatoxins. Polyamines (PAs) are ubiquitous polycations that influence normal growth, development, and stress responses in living organisms and have been shown to play a significant role in fungal pathogenesis. Biosynthesis of spermidine (Spd) is critical for cell growth as it is required for hypusination-mediated activation of eukaryotic translation initiation factor 5A (eIF5A), and other biochemical functions. The tri-amine Spd is synthesized from the diamine putrescine (Put) by the enzyme spermidine synthase (Spds). Inactivation of spds resulted in a total loss of growth and sporulation in vitro which could be partially restored by addition of exogenous Spd. Complementation of the Δspds mutant with a wild type (WT) A. flavus spds gene restored the WT phenotype. In WT A. flavus, exogenous supply of Spd (in vitro) significantly increased the production of sclerotia and SMs. Infection of maize kernels with the Δspds mutant resulted in a significant reduction in fungal growth, sporulation, and aflatoxin production compared to controls. Quantitative PCR of Δspds mutant infected seeds showed down-regulation of aflatoxin biosynthetic genes in the mutant compared to WT A. flavus infected seeds. Expression analyses of PA metabolism/transport genes during A. flavus-maize interaction showed significant increase in the expression of arginine decarboxylase (Adc) and S-adenosylmethionine decarboxylase (Samdc) genes in the maize host and PA uptake transporters in the fungus. The results presented here demonstrate that Spd biosynthesis is critical for normal development and pathogenesis of A. flavus and pre-treatment of a Δspds mutant with Spd or Spd uptake from the host plant, are insufficient to restore WT levels of pathogenesis and aflatoxin production during seed infection. The data presented here suggest that future studies targeting spermidine biosynthesis in A. flavus, using RNA interference-based host-induced gene silencing approaches, may be an effective strategy to reduce aflatoxin contamination in maize and possibly in other susceptible crops.
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Affiliation(s)
- Rajtilak Majumdar
- Food and Feed Safety Research Unit, United States Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, LA, United States
| | - Matt Lebar
- Food and Feed Safety Research Unit, United States Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, LA, United States
| | - Brian Mack
- Food and Feed Safety Research Unit, United States Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, LA, United States
| | - Rakesh Minocha
- United States Department of Agriculture Forest Service, Northern Research Station, Durham, NH, United States
| | - Subhash Minocha
- Department of Biological Sciences, University of New Hampshire, Durham, NH, United States
| | - Carol Carter-Wientjes
- Food and Feed Safety Research Unit, United States Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, LA, United States
| | - Christine Sickler
- Food and Feed Safety Research Unit, United States Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, LA, United States
| | - Kanniah Rajasekaran
- Food and Feed Safety Research Unit, United States Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, LA, United States
| | - Jeffrey W. Cary
- Food and Feed Safety Research Unit, United States Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, LA, United States
- *Correspondence: Jeffrey W. Cary,
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Amich J, Bignell E. Amino acid biosynthetic routes as drug targets for pulmonary fungal pathogens: what is known and why do we need to know more? Curr Opin Microbiol 2016; 32:151-158. [DOI: 10.1016/j.mib.2016.06.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 06/07/2016] [Accepted: 06/09/2016] [Indexed: 11/29/2022]
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18
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Dietl AM, Amich J, Leal S, Beckmann N, Binder U, Beilhack A, Pearlman E, Haas H. Histidine biosynthesis plays a crucial role in metal homeostasis and virulence of Aspergillus fumigatus. Virulence 2016; 7:465-76. [PMID: 26854126 PMCID: PMC4871644 DOI: 10.1080/21505594.2016.1146848] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Aspergillus fumigatus is the most prevalent airborne fungal pathogen causing invasive fungal infections in immunosuppressed individuals. The histidine biosynthetic pathway is found in bacteria, archaebacteria, lower eukaryotes, and plants, but is absent in mammals. Here we demonstrate that deletion of the gene encoding imidazoleglycerol-phosphate dehydratase (HisB) in A. fumigatus causes (i) histidine auxotrophy, (ii) decreased resistance to both starvation and excess of various heavy metals, including iron, copper and zinc, which play a pivotal role in antimicrobial host defense, (iii) attenuation of pathogenicity in 4 virulence models: murine pulmonary infection, murine systemic infection, murine corneal infection, and wax moth larvae. In agreement with the in vivo importance of histidine biosynthesis, the HisB inhibitor 3-amino-1,2,4-triazole reduced the virulence of the A. fumigatus wild type and histidine supplementation partially rescued virulence of the histidine-auxotrophic mutant in the wax moth model. Taken together, this study reveals limited histidine availability in diverse A. fumigatus host niches, a crucial role for histidine in metal homeostasis, and the histidine biosynthetic pathway as being an attractive target for development of novel antifungal therapy approaches.
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Affiliation(s)
- Anna-Maria Dietl
- a Division of Molecular Biology, Biocenter, Medical University of Innsbruck , Innsbruck , Austria
| | - Jorge Amich
- b IZKF Forschergruppe für Experimentelle Stammzelltransplantation, Medizinische Klinik und Poliklinik II & Universitäts-Kinderklinik , Würzburg , Germany
| | - Sixto Leal
- c Department of Ophthalmology and Visual Sciences , Case Western Reserve University , Cleveland , OH , USA
| | - Nicola Beckmann
- a Division of Molecular Biology, Biocenter, Medical University of Innsbruck , Innsbruck , Austria
| | - Ulrike Binder
- d Division of Hygiene & Medical Microbiology, Medical University of Innsbruck , Innsbruck , Austria
| | - Andreas Beilhack
- b IZKF Forschergruppe für Experimentelle Stammzelltransplantation, Medizinische Klinik und Poliklinik II & Universitäts-Kinderklinik , Würzburg , Germany
| | - Eric Pearlman
- c Department of Ophthalmology and Visual Sciences , Case Western Reserve University , Cleveland , OH , USA
| | - Hubertus Haas
- a Division of Molecular Biology, Biocenter, Medical University of Innsbruck , Innsbruck , Austria
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Galleria mellonella: An invertebrate model to study pathogenicity in correctly defined fungal species. Fungal Biol 2016; 120:288-95. [DOI: 10.1016/j.funbio.2015.06.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 06/05/2015] [Accepted: 06/08/2015] [Indexed: 11/18/2022]
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N-Chlorotaurine Exhibits Fungicidal Activity against Therapy-Refractory Scedosporium Species and Lomentospora prolificans. Antimicrob Agents Chemother 2015; 59:6454-62. [PMID: 26239996 DOI: 10.1128/aac.00957-15] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 07/24/2015] [Indexed: 01/26/2023] Open
Abstract
N-Chlorotaurine (NCT), a well-tolerated endogenous long-lived oxidant that can be applied topically as an antiseptic, was tested on its fungicidal activity against Scedosporium and Lomentospora, opportunistic fungi that cause severe infections with limited treatment options, mainly in immunocompromised patients. In quantitative killing assays, both hyphae and conidia of Scedosporium apiospermum, Scedosporium boydii, and Lomentospora prolificans (formerly Scedosporium prolificans) were killed by 55 mM (1.0%) NCT at pH 7.1 and 37°C, with a 1- to 4-log10 reduction in CFU after 4 h and a 4- to >6-log10 reduction after 24 h. The addition of ammonium chloride to NCT markedly increased this activity. LIVE/DEAD staining of conidia treated with 1.0% NCT for 0.5 to 3 h increased the permeability of the cell wall and membrane. Preincubation of the test fungi in 1.0% NCT for 10 to 60 min delayed the time to germination of conidia by 2 h to >12 h and reduced their germination rate by 10.0 to 100.0%. Larvae of Galleria mellonella infected with 1.0 × 10(7) conidia of S. apiospermum and S. boydii died at a rate of 90.0 to 100% after 8 to 12 days. The mortality rate was reduced to 20 to 50.0% if conidia were preincubated in 1.0% NCT for 0.5 h or if heat-inactivated conidia were used. Our study demonstrates the fungicidal activity of NCT against different Scedosporium and Lomentospora species. A postantifungal effect connected with a loss of virulence occurs after sublethal incubation times. The augmenting effect of ammonium chloride can be explained by the formation of monochloramine.
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Maurer E, Browne N, Surlis C, Jukic E, Moser P, Kavanagh K, Lass-Flörl C, Binder U. Galleria mellonella as a host model to study Aspergillus terreus virulence and amphotericin B resistance. Virulence 2015; 6:591-8. [PMID: 26107350 PMCID: PMC4720272 DOI: 10.1080/21505594.2015.1045183] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 04/21/2015] [Accepted: 04/21/2015] [Indexed: 10/23/2022] Open
Abstract
The aim of this study was to investigate if the alternative in vivo model Galleria mellonella can be used (i) to determine differences in pathogenicity of amphotericin B (AMB) resistant and susceptible A. terreus isolates, (ii) to evaluate AMB efficacy in vivo (iii) and to correlate outcome to in vitro susceptibility data. Larvae were infected with 2 A. terreus AMB resistant (ATR) and 3 AMB susceptible (ATS) isolates and survival rates were correlated to physiological attributes and killing ability of larval haemocytes. Additionally, infected larvae were treated with different concentrations of L-AMB. Haemocyte density were ascertained to evaluate the influence of L-AMB on the larval immune cells. Larvae were sensitive to A. terreus infection in an inoculum-size and temperature dependent manner. In vitro susceptibility to L-AMB correlated with in vivo outcome of antifungal treatment, defining an AMB susceptible strain cluster of A. terreus. Susceptibility to L-AMB increased virulence potential in the larval model, but this increase was also in accordance with faster growth and less damage caused by larval haemocytes. L-AMB treatment primed the larval immune response by increasing haemocyte density. G. mellonella provides a convenient model for the in vivo screening of A. terreus virulence and treatment options, contributing to the generation of a hypothesis that can be further tested in refined experiments in mammalian models.
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Affiliation(s)
- Elisabeth Maurer
- Division of Hygiene and Medical Microbiology; Medical University of Innsbruck; Innsbruck, Austria
| | - Niall Browne
- Medical Mycology Unit; Department of Biology; Maynooth University; Maynooth; Kildare, Ireland
| | - Carla Surlis
- Medical Mycology Unit; Department of Biology; Maynooth University; Maynooth; Kildare, Ireland
| | - Emina Jukic
- Division of Hygiene and Medical Microbiology; Medical University of Innsbruck; Innsbruck, Austria
| | - Patrizia Moser
- Department of Pathology; Medical University of Innsbruck; Innsbruck, Austria
| | - Kevin Kavanagh
- Medical Mycology Unit; Department of Biology; Maynooth University; Maynooth; Kildare, Ireland
| | - Cornelia Lass-Flörl
- Division of Hygiene and Medical Microbiology; Medical University of Innsbruck; Innsbruck, Austria
| | - Ulrike Binder
- Division of Hygiene and Medical Microbiology; Medical University of Innsbruck; Innsbruck, Austria
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Schafferer L, Beckmann N, Binder U, Brosch G, Haas H. AmcA-a putative mitochondrial ornithine transporter supporting fungal siderophore biosynthesis. Front Microbiol 2015; 6:252. [PMID: 25904899 PMCID: PMC4387927 DOI: 10.3389/fmicb.2015.00252] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 03/13/2015] [Indexed: 11/28/2022] Open
Abstract
Iron is an essential nutrient required for a wide range of cellular processes. The opportunistic fungal pathogen Aspergillus fumigatus employs low-molecular mass iron-specific chelators, termed siderophores, for uptake, storage and intracellular iron distribution, which play a crucial role in the pathogenicity of this fungus. Siderophore biosynthesis (SB) depends on coordination with the supply of its precursor ornithine, produced mitochondrially from glutamate or cytosolically via hydrolysis of arginine. In this study, we demonstrate a role of the putative mitochondrial transporter AmcA (AFUA_8G02760) in SB of A. fumigatus. Consistent with a role in cellular ornithine handling, AmcA-deficiency resulted in decreased cellular ornithine and arginine contents as well as decreased siderophore production on medium containing glutamine as the sole nitrogen source. In support, arginine and ornithine as nitrogen sources did not impact SB due to cytosolic ornithine availability. As revealed by Northern blot analysis, transcript levels of siderophore biosynthetic genes were unresponsive to the cellular ornithine level. In contrast to siderophore production, AmcA deficiency did only mildly decrease the cellular polyamine content, demonstrating cellular prioritization of ornithine use. Nevertheless, AmcA-deficiency increased the susceptibility of A. fumigatus to the polyamine biosynthesis inhibitor eflornithine, most likely due to the decreased ornithine pool. AmcA-deficiency decreased the growth rate particularly on ornithine as the sole nitrogen source during iron starvation and sufficiency, indicating an additional role in the metabolism and fitness of A. fumigatus, possibly in mitochondrial ornithine import. In the Galleria mellonella infection model, AmcA-deficiency did not affect virulence of A. fumigatus, most likely due to the residual siderophore production and arginine availability in this host niche.
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Affiliation(s)
- Lukas Schafferer
- Division of Molecular Biology/Biocenter, Medical University Innsbruck Innsbruck, Austria
| | - Nicola Beckmann
- Division of Molecular Biology/Biocenter, Medical University Innsbruck Innsbruck, Austria
| | - Ulrike Binder
- Division of Hygiene and Medical Microbiology, Medical University Innsbruck Innsbruck, Austria
| | - Gerald Brosch
- Division of Molecular Biology/Biocenter, Medical University Innsbruck Innsbruck, Austria
| | - Hubertus Haas
- Division of Molecular Biology/Biocenter, Medical University Innsbruck Innsbruck, Austria
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Chiapello M, Martino E, Perotto S. Common and metal-specific proteomic responses to cadmium and zinc in the metal tolerant ericoid mycorrhizal fungus Oidiodendron maius Zn. Metallomics 2015; 7:805-15. [PMID: 25761960 DOI: 10.1039/c5mt00024f] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Although adaptive metal tolerance may arise in fungal populations in polluted soils, the mechanisms underlying metal-specific tolerance are poorly understood. Comparative proteomics is a powerful tool to identify variation in protein profiles caused by changing environmental conditions, and was used to investigate protein accumulation in a metal tolerant isolate of the ericoid mycorrhizal fungus Oidiodendron maius exposed to zinc and cadmium. Two-dimensional gel electrophoresis and shotgun proteomics followed by mass spectrometry lead to the identification of common and metal-specific proteins and pathways. Proteins selectively induced by cadmium exposure were molecular chaperons of the Hsp90 family, cytoskeletal proteins and components of the translation machinery. Zinc significantly up-regulated metabolic pathways related to energy production and carbohydrates metabolism, likely mirroring zinc adaptation of this fungal isolate. Common proteins induced by the two metal ions were the antioxidant enzyme Cu/Zn superoxide dismutase and ubiquitin. In mycelia exposed to zinc and cadmium, both proteomic techniques also identified agmatinase, an enzyme involved in polyamine biosynthesis. This novel finding suggests that, like plants, polyamines may have important functions in response to abiotic environmental stress in fungi. Genetic evidence also suggests that the biosynthesis of polyamines via an alternative metabolic pathway may be widespread in fungi.
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Affiliation(s)
- M Chiapello
- Department of Life Sciences and Systems Biology, University of Torino, Viale Mattioli 25, 10125, Turin, Italy.
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Sheridan KJ, Dolan SK, Doyle S. Endogenous cross-talk of fungal metabolites. Front Microbiol 2015; 5:732. [PMID: 25601857 PMCID: PMC4283610 DOI: 10.3389/fmicb.2014.00732] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 12/04/2014] [Indexed: 12/21/2022] Open
Abstract
Non-ribosomal peptide (NRP) synthesis in fungi requires a ready supply of proteogenic and non-proteogenic amino acids which are subsequently incorporated into the nascent NRP via a thiotemplate mechanism catalyzed by NRP synthetases. Substrate amino acids can be modified prior to or during incorporation into the NRP, or following incorporation into an early stage amino acid-containing biosynthetic intermediate. These post-incorporation modifications involve a range of additional enzymatic activities including but not exclusively, monooxygenases, methyltransferases, epimerases, oxidoreductases, and glutathione S-transferases which are essential to effect biosynthesis of the final NRP. Likewise, polyketide biosynthesis is directly by polyketide synthase megaenzymes and cluster-encoded ancillary decorating enzymes. Additionally, a suite of additional primary metabolites, for example: coenzyme A (CoA), acetyl CoA, S-adenosylmethionine, glutathione (GSH), NADPH, malonyl CoA, and molecular oxygen, amongst others are required for NRP and polyketide synthesis (PKS). Clearly these processes must involve exquisite orchestration to facilitate the simultaneous biosynthesis of different types of NRPs, polyketides, and related metabolites requiring identical or similar biosynthetic precursors or co-factors. Moreover, the near identical structures of many natural products within a given family (e.g., ergot alkaloids), along with localization to similar regions within fungi (e.g., conidia) suggests that cross-talk may exist, in terms of biosynthesis and functionality. Finally, we speculate if certain biosynthetic steps involved in NRP and PKS play a role in cellular protection or environmental adaptation, and wonder if these enzymatic reactions are of equivalent importance to the actual biosynthesis of the final metabolite.
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Affiliation(s)
| | - Stephen K Dolan
- Department of Biology, Maynooth University Maynooth, Ireland
| | - Sean Doyle
- Department of Biology, Maynooth University Maynooth, Ireland
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Inhibitors of amino acids biosynthesis as antifungal agents. Amino Acids 2014; 47:227-49. [PMID: 25408465 PMCID: PMC4302243 DOI: 10.1007/s00726-014-1873-1] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 11/05/2014] [Indexed: 12/22/2022]
Abstract
Fungal microorganisms, including the human pathogenic yeast and filamentous fungi, are able to synthesize all proteinogenic amino acids, including nine that are essential for humans. A number of enzymes catalyzing particular steps of human-essential amino acid biosynthesis are fungi specific. Numerous studies have shown that auxotrophic mutants of human pathogenic fungi impaired in biosynthesis of particular amino acids exhibit growth defect or at least reduced virulence under in vivo conditions. Several chemical compounds inhibiting activity of one of these enzymes exhibit good antifungal in vitro activity in minimal growth media, which is not always confirmed under in vivo conditions. This article provides a comprehensive overview of the present knowledge on pathways of amino acids biosynthesis in fungi, with a special emphasis put on enzymes catalyzing particular steps of these pathways as potential targets for antifungal chemotherapy.
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Abstract
Siderophores are chelators synthesized by microbes to sequester iron. This article summarizes the knowledge on the fungal siderophore metabolism with a focus on Aspergillus fumigatus. In recent years, A. fumigatus became a role model for fungal biosynthesis, uptake and degradation of siderophores as well as regulation of siderophore-mediated iron handling and the elucidation of siderophore functions. Siderophore functions comprise uptake, intracellular transport and storage of iron. This proved to be crucial not only for adaptation to iron starvation conditions but also for germination, asexual and sexual propagation, antioxidative defense, mutual interaction, microbial competition as well as virulence in plant and animal hosts. Recent studies also indicate the high potential of siderophores and its biosynthetic pathway to improve diagnosis and therapy of fungal infections.
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Affiliation(s)
- Hubertus Haas
- Division of Molecular Biology/Biocenter, Innsbruck Medical University, Innrain 80-82, A-6020 Innsbruck, Austria.
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