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Goich D, Bloom ALM, Duffy SR, Ventura MN, Panepinto JC. Gcn2 rescues reprogramming in the absence of Hog1/p38 signaling in C. neoformans during thermal stress. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.11.598457. [PMID: 38915642 PMCID: PMC11195226 DOI: 10.1101/2024.06.11.598457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
The fungus Cryptococcus neoformans is an opportunistic pathogen of people that reprograms its translatome to facilitate adaptation and virulence within the host. We studied the role of Hog1/p38 in reprogramming translation during thermal stress adaptation, and found that this pathway acts on translation via crosstalk with the Gcn2 pathway, a well-studied regulator of general translation control. Using a combination of molecular assays and phenotypic analysis, we show that increased output from the Gcn2 pathway in a Hog1 deletion mutant is associated with rescue of thermal stress adaptation at both molecular and phenotypic scales. We characterize known outputs of the Hog1 pathway during thermal stress as either Gcn2-dependent or Gcn2-independent, and demonstrate that Hog1 activation regulates the Gcn2 pathway even in the absence of thermal stress. Finally, we implicate this phenomenon in another Hog1-regulated process, morphogenesis, and recapitulate Hog1-Gcn2 crosstalk in the distantly related fungal pathogen, Candida albicans. Our results point to an important link between the stress response machinery and translation control, and clarify the etiology of phenotypes associated with Hog1 deletion. More broadly, this study highlights complex interplay between core conserved signal transduction pathways and the utility of molecular assays to better understand how these pathways are connected.
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Affiliation(s)
- David Goich
- Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Amanda L. M. Bloom
- Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Sean R. Duffy
- Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Maritza N. Ventura
- Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - John C. Panepinto
- Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
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2
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van Rhijn N, Zhao C, Al-Furaji N, Storer ISR, Valero C, Gago S, Chown H, Baldin C, Grant RF, Bin Shuraym H, Ivanova L, Kniemeyer O, Krüger T, Bignell E, Goldman GH, Amich J, Delneri D, Bowyer P, Brakhage AA, Haas H, Bromley MJ. Functional analysis of the Aspergillus fumigatus kinome identifies a druggable DYRK kinase that regulates septal plugging. Nat Commun 2024; 15:4984. [PMID: 38862481 PMCID: PMC11166925 DOI: 10.1038/s41467-024-48592-8] [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: 05/31/2023] [Accepted: 05/03/2024] [Indexed: 06/13/2024] Open
Abstract
More than 10 million people suffer from lung diseases caused by the pathogenic fungus Aspergillus fumigatus. Azole antifungals represent first-line therapeutics for most of these infections but resistance is rising, therefore the identification of antifungal targets whose inhibition synergises with the azoles could improve therapeutic outcomes. Here, we generate a library of 111 genetically barcoded null mutants of Aspergillus fumigatus in genes encoding protein kinases, and show that loss of function of kinase YakA results in hypersensitivity to the azoles and reduced pathogenicity. YakA is an orthologue of Candida albicans Yak1, a TOR signalling pathway kinase involved in modulation of stress responsive transcriptional regulators. We show that YakA has been repurposed in A. fumigatus to regulate blocking of the septal pore upon exposure to stress. Loss of YakA function reduces the ability of A. fumigatus to penetrate solid media and to grow in mouse lung tissue. We also show that 1-ethoxycarbonyl-beta-carboline (1-ECBC), a compound previously shown to inhibit C. albicans Yak1, prevents stress-mediated septal spore blocking and synergises with the azoles to inhibit A. fumigatus growth.
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Affiliation(s)
- Norman van Rhijn
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomic Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Can Zhao
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomic Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Narjes Al-Furaji
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomic Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
- Department of Pharmacology, College of Medicine, University of Kerbala, Kerbala, Iraq
| | - Isabelle S R Storer
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomic Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Clara Valero
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomic Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Sara Gago
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomic Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Harry Chown
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomic Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Clara Baldin
- Division of Molecular Biology, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Rachael-Fortune Grant
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomic Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Hajer Bin Shuraym
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomic Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud Bin Abdulaziz University for Health Sciences, 11481, Riyadh, Saudi Arabia
| | - Lia Ivanova
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (Leibniz-HKI), Jena, Germany
| | - Olaf Kniemeyer
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (Leibniz-HKI), Jena, Germany
| | - Thomas Krüger
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (Leibniz-HKI), Jena, Germany
| | - Elaine Bignell
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomic Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
- MRC Centre for Medical Mycology, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
| | - Gustavo H Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Jorge Amich
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomic Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
- Mycology Reference Laboratory (Laboratorio de Referencia e Investigación en Micología [LRIM]), National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
| | - Daniela Delneri
- Division of Evolution, Infection and Genomic Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Paul Bowyer
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomic Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Axel A Brakhage
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud Bin Abdulaziz University for Health Sciences, 11481, Riyadh, Saudi Arabia
- Department of Microbiology and Molecular Biology, Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Hubertus Haas
- Division of Molecular Biology, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Michael J Bromley
- Manchester Fungal Infection Group, Division of Evolution, Infection and Genomic Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
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3
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Xie J, Rybak JM, Martin-Vicente A, Guruceaga X, Thorn HI, Nywening AV, Ge W, Parker JE, Kelly SL, Rogers PD, Fortwendel JR. The sterol C-24 methyltransferase encoding gene, erg6, is essential for viability of Aspergillus species. Nat Commun 2024; 15:4261. [PMID: 38769341 PMCID: PMC11106247 DOI: 10.1038/s41467-024-48767-3] [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: 08/28/2023] [Accepted: 05/09/2024] [Indexed: 05/22/2024] Open
Abstract
Triazoles, the most widely used class of antifungal drugs, inhibit the biosynthesis of ergosterol, a crucial component of the fungal plasma membrane. Inhibition of a separate ergosterol biosynthetic step, catalyzed by the sterol C-24 methyltransferase Erg6, reduces the virulence of pathogenic yeasts, but its effects on filamentous fungal pathogens like Aspergillus fumigatus remain unexplored. Here, we show that the lipid droplet-associated enzyme Erg6 is essential for the viability of A. fumigatus and other Aspergillus species, including A. lentulus, A. terreus, and A. nidulans. Downregulation of erg6 causes loss of sterol-rich membrane domains required for apical extension of hyphae, as well as altered sterol profiles consistent with the Erg6 enzyme functioning upstream of the triazole drug target, Cyp51A/Cyp51B. Unexpectedly, erg6-repressed strains display wild-type susceptibility against the ergosterol-active triazole and polyene antifungals. Finally, we show that erg6 repression results in significant reduction in mortality in a murine model of invasive aspergillosis. Taken together with recent studies, our work supports Erg6 as a potentially pan-fungal drug target.
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Affiliation(s)
- Jinhong Xie
- Graduate Program in Pharmaceutical Sciences, College of Graduate Health Sciences, University of Tennessee Health Science Center, Memphis, TN, USA
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Jeffrey M Rybak
- Department of Pharmacy and Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Adela Martin-Vicente
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Xabier Guruceaga
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Harrison I Thorn
- Graduate Program in Pharmaceutical Sciences, College of Graduate Health Sciences, University of Tennessee Health Science Center, Memphis, TN, USA
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Ashley V Nywening
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
- Integrated Program in Biomedical Sciences, College of Graduate Health Sciences, University of Tennessee Health Science Center, Memphis, TN, USA
- Department of Microbiology, Immunology, and Biochemistry, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Wenbo Ge
- Department of Pharmacy and Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Josie E Parker
- Molecular Biosciences Division, School of Biosciences, Cardiff University, Cardiff, Wales, UK
| | - Steven L Kelly
- Institute of Life Science, Swansea University Medical School, Swansea, Wales, UK
| | - P David Rogers
- Department of Pharmacy and Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Jarrod R Fortwendel
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA.
- Department of Microbiology, Immunology, and Biochemistry, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA.
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4
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Calise DG, Park SC, Bok JW, Goldman GH, Keller NP. An oxylipin signal confers protection against antifungal echinocandins in pathogenic aspergilli. Nat Commun 2024; 15:3770. [PMID: 38704366 PMCID: PMC11069582 DOI: 10.1038/s41467-024-48231-2] [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: 09/28/2023] [Accepted: 04/23/2024] [Indexed: 05/06/2024] Open
Abstract
Aspergillus fumigatus is the leading causative agent of life-threatening invasive aspergillosis in immunocompromised individuals. One antifungal class used to treat Aspergillus infections is the fungistatic echinocandins, semisynthetic drugs derived from naturally occurring fungal lipopeptides. By inhibiting beta-1,3-glucan synthesis, echinocandins cause both fungistatic stunting of hyphal growth and repeated fungicidal lysis of apical tip compartments. Here, we uncover an endogenous mechanism of echinocandin tolerance in A. fumigatus whereby the inducible oxylipin signal 5,8-diHODE confers protection against tip lysis via the transcription factor ZfpA. Treatment of A. fumigatus with echinocandins induces 5,8-diHODE synthesis by the fungal oxygenase PpoA in a ZfpA dependent manner resulting in a positive feedback loop. This protective 5,8-diHODE/ZfpA signaling relay is conserved among diverse isolates of A. fumigatus and in two other Aspergillus pathogens. Our findings reveal an oxylipin-directed growth program-possibly arisen through natural encounters with native echinocandin producing fungi-that enables echinocandin tolerance in pathogenic aspergilli.
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Affiliation(s)
- Dante G Calise
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI, USA
| | - Sung Chul Park
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
| | - Jin Woo Bok
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
| | - Gustavo H Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
- National Institute of Science and Technology in Human Pathogenic Fungi, Ribeirão Preto, Brazil
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA.
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI, USA.
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5
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Thorn HI, Guruceaga X, Martin-Vicente A, Nywening AV, Xie J, Ge W, Fortwendel JR. MOB-mediated regulation of septation initiation network (SIN) signaling is required for echinocandin-induced hyperseptation in Aspergillus fumigatus. mSphere 2024; 9:e0069523. [PMID: 38349166 DOI: 10.1128/msphere.00695-23] [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: 11/10/2023] [Accepted: 01/17/2024] [Indexed: 03/27/2024] Open
Abstract
Aspergillus fumigatus is a major invasive mold pathogen and the most frequent etiologic agent of invasive aspergillosis. The currently available treatments for invasive aspergillosis are limited in both number and efficacy. Our recent work has uncovered that the β-glucan synthase inhibitors, the echinocandins, are fungicidal against strains of A. fumigatus with defects in septation initiation network (SIN) kinase activity. These drugs are known to be fungistatic against strains with normal septation. Surprisingly, SIN kinase mutant strains also failed to invade lung tissue and were significantly less virulent in immunosuppressed mouse models. Inhibiting septation in filamentous fungi is therefore an exciting therapeutic prospect to both reduce virulence and improve current antifungal therapy. However, the SIN remains understudied in pathogenic fungi. To address this knowledge gap, we characterized the putative regulatory components of the A. fumigatus SIN. These included the GTPase, SpgA, it's two-component GTPase-activating protein, ByrA/BubA, and the kinase activators, SepM and MobA. Deletion of spgA, byrA, or bubA resulted in no overt septation or echinocandin susceptibility phenotypes. In contrast, our data show that deletion of sepM or mobA largely phenocopies disruption of their SIN kinase binding partners, sepL and sidB, respectively. Reduced septum formation, echinocandin hypersusceptibility, and reduced virulence were generated by loss of either gene. These findings provide strong supporting evidence that septa are essential not only for withstanding the cell wall disrupting effects of echinocandins but are also critical for the establishment of invasive disease. Therefore, pharmacological SIN inhibition may be an exciting strategy for future antifungal drug development.IMPORTANCESepta are important structural determinants of echinocandin susceptibility and tissue invasive growth for the ubiquitous fungal pathogen Aspergillus fumigatus. Components of the septation machinery therefore represent promising novel antifungal targets to improve echinocandin activity and reduce virulence. However, little is known about septation regulation in A. fumigatus. Here, we characterize the predicted regulatory components of the A. fumigatus septation initiation network. We show that the kinase activators SepM and MobA are vital for proper septation and echinocandin resistance, with MobA playing an essential role. Null mutants of mobA displayed significantly reduced virulence in a mouse model, underscoring the importance of this pathway for A. fumigatus pathogenesis.
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Affiliation(s)
- Harrison I Thorn
- Graduate Program in Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee, USA
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Xabier Guruceaga
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Adela Martin-Vicente
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Ashley V Nywening
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee, USA
- Integrated Program in Biomedical Sciences, College of Graduate Health Sciences, University of Tennessee Health Science Center, Memphis, Tennessee, USA
- Department of Microbiology, Immunology, and Biochemistry, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Jinhong Xie
- Graduate Program in Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee, USA
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Wenbo Ge
- Department of Pharmacy and Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Jarrod R Fortwendel
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee, USA
- Department of Microbiology, Immunology, and Biochemistry, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee, USA
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6
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Agirrezabala Z, Guruceaga X, Martin-Vicente A, Otamendi A, Fagoaga A, Fortwendel JR, Espeso EA, Etxebeste O. Identification and functional characterization of the putative members of the CTDK-1 kinase complex as regulators of growth and development in Aspergillus nidulans and Aspergillus fumigatus. mBio 2023; 14:e0245223. [PMID: 37943062 PMCID: PMC10746219 DOI: 10.1128/mbio.02452-23] [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: 09/12/2023] [Accepted: 10/03/2023] [Indexed: 11/10/2023] Open
Abstract
IMPORTANCE Aspergillus fumigatus has been included by the World Health Organization in the priority list of fungal pathogens because (i) it causes 90% of invasive aspergillosis cases, with a high mortality rate, and (ii) infections are becoming increasingly resistant to azole antifungals. A. nidulans is an opportunistic pathogen and a saprotroph which has served during the last 80 years as a reference system for filamentous fungi. Here, we characterized the role in morphogenesis and development of the putative transcriptional cyclin/kinase complex CTDK-1 in both aspergilli. The null mutants of the corresponding genes showed delayed germination, aberrant conidiophore development, and inhibition of cleistothecia production. While in higher eukaryotes this complex is formed only by a cyclin and a kinase, the fungal complex would incorporate a fungal-specific third component, FlpB, which would enable the interaction between the kinase (Stk47) and the cyclin (FlpA) and may be used as a target for antifungals.
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Affiliation(s)
- Z. Agirrezabala
- Laboratory of Biology, Department of Applied Chemistry, Faculty of Chemistry, University of the Basque Country, UPV/EHU, San Sebastian, Spain
| | - X. Guruceaga
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - A. Martin-Vicente
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - A. Otamendi
- Laboratory of Biology, Department of Applied Chemistry, Faculty of Chemistry, University of the Basque Country, UPV/EHU, San Sebastian, Spain
| | - A. Fagoaga
- Laboratory of Biology, Department of Applied Chemistry, Faculty of Chemistry, University of the Basque Country, UPV/EHU, San Sebastian, Spain
| | - J. R. Fortwendel
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - E. A. Espeso
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas (CSIC), Madrid, Spain
| | - O. Etxebeste
- Laboratory of Biology, Department of Applied Chemistry, Faculty of Chemistry, University of the Basque Country, UPV/EHU, San Sebastian, Spain
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7
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Xie J, Rybak JM, Martin-Vicente A, Guruceaga X, Thorn HI, Nywening AV, Ge W, Parker JE, Kelly SL, Rogers PD, Fortwendel JR. The sterol C-24 methyltransferase encoding gene, erg6, is essential for viability of Aspergillus species. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.08.552489. [PMID: 37609350 PMCID: PMC10441335 DOI: 10.1101/2023.08.08.552489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Ergosterol is a critical component of fungal plasma membranes. Although many currently available antifungal compounds target the ergosterol biosynthesis pathway for antifungal effect, current knowledge regarding ergosterol synthesis remains incomplete for filamentous fungal pathogens like Aspergillus fumigatus. Here, we show for the first time that the lipid droplet-associated sterol C-24 methyltransferase, Erg6, is essential for A. fumigatus viability. We further show that this essentiality extends to additional Aspergillus species, including A. lentulus, A. terreus, and A. nidulans. Neither the overexpression of a putative erg6 paralog, smt1, nor the exogenous addition of ergosterol could rescue erg6 deficiency. Importantly, Erg6 downregulation results in a dramatic decrease in ergosterol and accumulation in lanosterol and is further characterized by diminished sterol-rich plasma membrane domains (SRDs) at hyphal tips. Unexpectedly, erg6 repressed strains demonstrate wild-type susceptibility against the ergosterol-active triazole and polyene antifungals. Finally, repressing erg6 expression reduced fungal burden accumulation in a murine model of invasive aspergillosis. Taken together, our studies suggest that Erg6, which shows little homology to mammalian proteins, is potentially an attractive antifungal drug target for therapy of Aspergillus infections.
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Affiliation(s)
- Jinhong Xie
- Graduate Program in Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN USA
| | - Jeffrey M. Rybak
- Department of Pharmacy and Pharmaceutical Sciences, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Adela Martin-Vicente
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN USA
| | - Xabier Guruceaga
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN USA
| | - Harrison I. Thorn
- Graduate Program in Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN USA
| | - Ashley V. Nywening
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN USA
- Integrated Program in Biomedical Sciences, College of Graduate Health Sciences, University of Tennessee Health Science Center, Memphis, TN, USA
- Department of Microbiology, Immunology, and Biochemistry, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Wenbo Ge
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN USA
| | - Josie E. Parker
- Molecular Biosciences Division, School of Biosciences, Cardiff University, Cardiff, Wales, UK
| | - Steven L. Kelly
- Institute of Life Science, Swansea University Medical School, Swansea, Wales, UK
| | - P. David Rogers
- Department of Pharmacy and Pharmaceutical Sciences, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Jarrod R. Fortwendel
- Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN USA
- Department of Microbiology, Immunology, and Biochemistry, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
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8
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van Rhijn N, Zhao C, Al-Furaji N, Storer I, Valero C, Gago S, Chown H, Baldin C, Fortune-Grant R, Shuraym HB, Ivanova L, Kniemeyer O, Krüger T, Bignell E, Goldman G, Amich J, Delneri D, Bowyer P, Brakhage A, Haas H, Bromley M. Functional analysis of the Aspergillus fumigatus kinome reveals a DYRK kinase involved in septal plugging is a novel antifungal drug target. RESEARCH SQUARE 2023:rs.3.rs-2960526. [PMID: 37398159 PMCID: PMC10312919 DOI: 10.21203/rs.3.rs-2960526/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
More than 10 million people suffer from lung diseases caused by the pathogenic fungus Aspergillus fumigatus. The azole class of antifungals represent first line therapeutics for most of these infections however resistance is rising. Identification of novel antifungal targets that, when inhibited, synergise with the azoles will aid the development of agents that can improve therapeutic outcomes and supress the emergence of resistance. As part of the A. fumigatus genome-wide knockout program (COFUN), we have completed the generation of a library that consists of 120 genetically barcoded null mutants in genes that encode the protein kinase cohort of A. fumigatus. We have employed a competitive fitness profiling approach (Bar-Seq), to identify targets which when deleted result in hypersensitivity to the azoles and fitness defects in a murine host. The most promising candidate from our screen is a previously uncharacterised DYRK kinase orthologous to Yak1 of Candida albicans, a TOR signalling pathway kinase involved in modulation of stress responsive transcriptional regulators. Here we show that the orthologue YakA has been repurposed in A. fumigatus to regulate blocking of the septal pore upon exposure to stress via phosphorylation of the Woronin body tethering protein Lah. Loss of YakA function reduces the ability of A. fumigatus to penetrate solid media and impacts growth in murine lung tissue. We also show that 1-ethoxycarbonyl-beta-carboline (1-ECBC), a compound previously shown to inhibit Yak1 in C. albicans prevents stress mediated septal spore blocking and synergises with the azoles to inhibit A. fumigatus growth.
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Affiliation(s)
| | - Can Zhao
- Manchester Fungal Infection Group
| | | | | | | | | | | | | | | | | | - Lia Ivanova
- Leibniz Institute for Natural Product Research and Infection Biology
| | - Olaf Kniemeyer
- Leibniz Institute for Natural Product Research and Infection Biology
| | - Thomas Krüger
- Leibniz Institute for Natural Product Research and Infection Biology
| | | | - Gustavo Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Bloco Q, Universidade de São Paulo
| | | | | | | | - Axel Brakhage
- Leibniz Institute for Natural Product Research and Infection Biology - University of Jena
| | - Hubertus Haas
- Institute of Molecular Biology/Biocenter, Innsbruck Medical University
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Schoen TJ, Calise DG, Bok JW, Giese MA, Nwagwu CD, Zarnowski R, Andes D, Huttenlocher A, Keller NP. Aspergillus fumigatus transcription factor ZfpA regulates hyphal development and alters susceptibility to antifungals and neutrophil killing during infection. PLoS Pathog 2023; 19:e1011152. [PMID: 37126504 PMCID: PMC10174577 DOI: 10.1371/journal.ppat.1011152] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 05/11/2023] [Accepted: 04/18/2023] [Indexed: 05/02/2023] Open
Abstract
Hyphal growth is essential for host colonization during Aspergillus infection. The transcription factor ZfpA regulates A. fumigatus hyphal development including branching, septation, and cell wall composition. However, how ZfpA affects fungal growth and susceptibility to host immunity during infection has not been investigated. Here, we use the larval zebrafish-Aspergillus infection model and primary human neutrophils to probe how ZfpA affects A. fumigatus pathogenesis and response to antifungal drugs in vivo. ZfpA deletion promotes fungal clearance and attenuates virulence in wild-type hosts and this virulence defect is abrogated in neutrophil-deficient zebrafish. ZfpA deletion also increases susceptibility to human neutrophils ex vivo while overexpression impairs fungal killing. Overexpression of ZfpA confers protection against the antifungal caspofungin by increasing chitin synthesis during hyphal development, while ZfpA deletion reduces cell wall chitin and increases caspofungin susceptibility in neutrophil-deficient zebrafish. These findings suggest a protective role for ZfpA activity in resistance to the innate immune response and antifungal treatment during A. fumigatus infection.
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Affiliation(s)
- Taylor J. Schoen
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Comparative Biomedical Sciences Graduate Program, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Dante G. Calise
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Jin Woo Bok
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Morgan A. Giese
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Cellular and Molecular Biology Graduate Program, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Chibueze D. Nwagwu
- Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Robert Zarnowski
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - David Andes
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Anna Huttenlocher
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Pediatrics, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Nancy P. Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
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Schoen TJ, Calise DG, Bok JW, Nwagwu CD, Zarnowski R, Andes D, Huttenlocher A, Keller NP. Aspergillus fumigatus transcription factor ZfpA regulates hyphal development and alters susceptibility to antifungals and neutrophil killing during infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.25.525624. [PMID: 36747761 PMCID: PMC9901008 DOI: 10.1101/2023.01.25.525624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Hyphal growth is essential for host colonization during Aspergillus infection. The transcription factor ZfpA regulates A. fumigatus hyphal development including branching, septation, and cell wall composition. However, how ZfpA affects fungal growth and susceptibility to host immunity during infection has not been investigated. Here, we use the larval zebrafish- Aspergillus infection model and primary human neutrophils to probe how ZfpA affects A. fumigatus pathogenesis and response to antifungal drugs in vivo . ZfpA deletion promotes fungal clearance and attenuates virulence in wild-type hosts and this virulence defect is abrogated in neutrophil-deficient zebrafish. ZfpA deletion also increases susceptibility to human neutrophils ex vivo while overexpression impairs fungal killing. Overexpression of ZfpA confers protection against the antifungal caspofungin by increasing chitin synthesis during hyphal development, while ZfpA deletion reduces cell wall chitin and increases caspofungin susceptibility in neutrophil-deficient zebrafish. These findings suggest a protective role for ZfpA activity in resistance to the innate immune response and antifungal treatment during A. fumigatus infection. Author Summary Aspergillus fumigatus is a common environmental fungus that can infect immunocompromised people and cause a life-threatening disease called invasive aspergillosis. An important step during infection is the development of A. fumigatus filaments known as hyphae. A. fumigatus uses hyphae to acquire nutrients and invade host tissues, leading to tissue damage and disseminated infection. In this study we report that a regulator of gene transcription in A. fumigatus called ZfpA is important for hyphal growth during infection. We find that ZfpA activity protects the fungus from being killed by innate immune cells and decreases the efficacy of antifungal drugs during infection by regulating construction of the cell wall, an important protective layer for fungal pathogens. Our study introduces ZfpA as an important genetic regulator of stress tolerance during infection that protects A. fumigatus from the host immune response and antifungal drugs.
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Affiliation(s)
- Taylor J. Schoen
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Comparative Biomedical Sciences Graduate Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Dante G. Calise
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Jin Woo Bok
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | | | - Robert Zarnowski
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - David Andes
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Anna Huttenlocher
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Pediatrics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Nancy P. Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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CRISPR/Cas9-Based Genome Editing and Its Application in Aspergillus Species. J Fungi (Basel) 2022; 8:jof8050467. [PMID: 35628723 PMCID: PMC9143064 DOI: 10.3390/jof8050467] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 04/28/2022] [Accepted: 04/29/2022] [Indexed: 02/04/2023] Open
Abstract
Aspergillus, a genus of filamentous fungi, is extensively distributed in nature and plays crucial roles in the decomposition of organic materials as an important environmental microorganism as well as in the traditional fermentation and food processing industries. Furthermore, due to their strong potential to secrete a large variety of hydrolytic enzymes and other natural products by manipulating gene expression and/or introducing new biosynthetic pathways, several Aspergillus species have been widely exploited as microbial cell factories. In recent years, with the development of next-generation genome sequencing technology and genetic engineering methods, the production and utilization of various homo-/heterologous-proteins and natural products in Aspergillus species have been well studied. As a newly developed genome editing technology, the clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) system has been used to edit and modify genes in Aspergilli. So far, the CRISPR/Cas9-based approach has been widely employed to improve the efficiency of gene modification in the strain type Aspergillus nidulans and other industrially important and pathogenic Aspergillus species, including Aspergillus oryzae, Aspergillus niger, and Aspergillus fumigatus. This review highlights the current development of CRISPR/Cas9-based genome editing technology and its application in basic research and the production of recombination proteins and natural products in the Aspergillus species.
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Aspergillus nidulans Septa Are Indispensable for Surviving Cell Wall Stress. Microbiol Spectr 2022; 10:e0206321. [PMID: 35107348 PMCID: PMC8809332 DOI: 10.1128/spectrum.02063-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Septation in filamentous fungi is a normal part of development, which involves the formation of cross-hyphal bulkheads, typically containing pores, allowing cytoplasmic streaming between compartments. Based on previous findings regarding septa and cell wall stress, we hypothesized that septa are critical for survival during cell wall stress. To test this hypothesis, we used known Aspergillus nidulans septation-deficient mutants (ΔsepH, Δbud3, Δbud4, and Δrho4) and six antifungal compounds. Three of these compounds (micafungin, Congo red, and calcofluor white) are known cell wall stressors which activate the cell wall integrity signaling pathway (CWIS), while the three others (cycloheximide, miconazole, and 2,3-butanedione monoxime) perturb specific cellular processes not explicitly related to the cell wall. Our results show that deficiencies in septation lead to fungi which are more susceptible to cell wall-perturbing compounds but are no more susceptible to other antifungal compounds than a control. This implies that septa play a critical role in surviving cell wall stress. IMPORTANCE The ability to compartmentalize potentially lethal damage via septation appears to provide filamentous fungi with a facile means to tolerate diverse forms of stress. However, it remains unknown whether this mechanism is deployed in response to all forms of stress or is limited to specific perturbations. Our results support the latter possibility by showing that presence of septa promotes survival in response to cell wall damage but plays no apparent role in coping with other unrelated forms of stress. Given that cell wall damage is a primary effect caused by exposure to the echinocandin class of antifungal agents, our results emphasize the important role that septa might play in enabling resistance to these drugs. Accordingly, the inhibition of septum formation could conceivably represent an attractive approach to potentiating the effects of echinocandins and mitigating resistance in human fungal pathogens.
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