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Antagonism of the Azoles to Olorofim and Cross-Resistance Are Governed by Linked Transcriptional Networks in Aspergillus fumigatus. mBio 2022; 13:e0221522. [PMID: 36286521 PMCID: PMC9765627 DOI: 10.1128/mbio.02215-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Aspergillosis, in its various manifestations, is a major cause of morbidity and mortality. Very few classes of antifungal drugs have been approved for clinical use to treat these diseases and resistance to the first-line therapeutic class, the triazoles are increasing. A new class of antifungals that target pyrimidine biosynthesis, the orotomides, are currently in development with the first compound in this class, olorofim in late-stage clinical trials. In this study, we identified an antagonistic action of the triazoles on the action of olorofim. We showed that this antagonism was the result of an azole-induced upregulation of the pyrimidine biosynthesis pathway. Intriguingly, we showed that loss of function in the higher order transcription factor, HapB a member of the heterotrimeric HapB/C/E (CBC) complex or the regulator of nitrogen metabolic genes AreA, led to cross-resistance to both the azoles and olorofim, indicating that factors that govern resistance were under common regulatory control. However, the loss of azole-induced antagonism required decoupling of the pyrimidine biosynthetic pathway in a manner independent of the action of a single transcription factor. Our study provided evidence for complex transcriptional crosstalk between the pyrimidine and ergosterol biosynthetic pathways. IMPORTANCE Aspergillosis is a spectrum of diseases and a major cause of morbidity and mortality. To treat these diseases, there are a few classes of antifungal drugs approved for clinical use. Resistance to the first line treatment, the azoles, is increasing. The first antifungal, olorofim, which is in the novel class of orotomides, is currently in development. Here, we showed an antagonistic effect between the azoles and olorofim, which was a result of dysregulation of the pyrimidine pathway, the target of olorofim, and the ergosterol biosynthesis pathway, the target of the azoles.
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Gawlik J, Koper M, Bogdanowicz A, Weglenski P, Dzikowska A. Nuclear Functions of KaeA, a Subunit of the KEOPS Complex in Aspergillus nidulans. Int J Mol Sci 2022; 23:ijms231911138. [PMID: 36232439 PMCID: PMC9570407 DOI: 10.3390/ijms231911138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 09/10/2022] [Accepted: 09/14/2022] [Indexed: 12/03/2022] Open
Abstract
Kae1 is a subunit of the highly evolutionarily conserved KEOPS/EKC complex, which is involved in universal (t6A37) tRNA modification. Several reports have discussed the participation of this complex in transcription regulation in yeast and human cells, including our previous observations of KaeA, an Aspergillus nidulans homologue of Kae1p. The aim of this project was to confirm the role of KaeA in transcription, employing high-throughput transcriptomic (RNA-Seq and ChIP-Seq) and proteomic (LC-MS) analysis. We confirmed that KaeA is a subunit of the KEOPS complex in A. nidulans. An analysis of kaeA19 and kaeA25 mutants showed that, although the (t6A37) tRNA modification is unaffected in both mutants, they reveal significantly altered transcriptomes compared to the wild type. The finding that KaeA is localized in chromatin and identifying its protein partners allows us to postulate an additional nuclear function for the protein. Our data shed light on the universal bi-functional role of this factor and proves that the activity of this protein is not limited to tRNA modification in cytoplasm, but also affects the transcriptional activity of a number of nuclear genes. Data are available via the NCBI’s GEO database under identifiers GSE206830 (RNA-Seq) and GSE206874 (ChIP-Seq), and via ProteomeXchange with identifier PXD034554 (proteomic).
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Affiliation(s)
- Joanna Gawlik
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawińskiego 5A, 02-106 Warsaw, Poland
- Centre of New Technologies, University of Warsaw, Żwirki i Wigury 93, 02-089 Warsaw, Poland
- College of Inter-Faculty Individual Studies in Mathematics and Natural Sciences, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland
| | - Michal Koper
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawińskiego 5A, 02-106 Warsaw, Poland
| | - Albert Bogdanowicz
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5A, 02-106 Warsaw, Poland
| | - Piotr Weglenski
- Centre of New Technologies, University of Warsaw, Żwirki i Wigury 93, 02-089 Warsaw, Poland
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5A, 02-106 Warsaw, Poland
| | - Agnieszka Dzikowska
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawińskiego 5A, 02-106 Warsaw, Poland
- Correspondence: or
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Kühbacher A, Peiffer M, Hortschansky P, Merschak P, Bromley MJ, Haas H, Brakhage AA, Gsaller F. Azole Resistance-Associated Regulatory Motifs within the Promoter of cyp51A in Aspergillus fumigatus. Microbiol Spectr 2022; 10:e0120922. [PMID: 35575535 PMCID: PMC9241776 DOI: 10.1128/spectrum.01209-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 04/15/2022] [Indexed: 11/20/2022] Open
Abstract
Aspergillus fumigatus is one of the deadliest fungal species, causing hundreds of thousands of deaths each year. Because azoles provide the preferred first-line option for treatment of aspergillosis, the increase in rates of resistance and the poor therapeutic outcomes for patients infected with a resistant isolate constitute a serious global health threat. Azole resistance is frequently associated with specific tandem repeat duplications of a promoter element upstream of cyp51A, the gene that encodes the target for this drug class in A. fumigatus. This promoter element is recognized by the activating transcription factors SrbA and AtrR. This region also provides a docking platform for the CCAAT-binding complex (CBC) and HapX, which cooperate in the regulation of genes involved in iron-consuming pathways, including cyp51A. Here, we studied the regulatory contributions of SrbA, AtrR, CBC, and HapX binding sites to cyp51A expression and azole resistance under different iron availability employing promoter mutational analysis and protein-DNA interaction analysis. This strategy revealed iron status-dependent and -independent roles of these regulatory elements. We show that promoter occupation by both AtrR and SrbA is required for iron-independent steady-state transcriptional activation of cyp51A and its induction during short-term iron exposure relies on HapX binding. We further reveal the HapX binding site as a repressor element, disruption of which increases cyp51A expression and azole resistance regardless of iron availability. IMPORTANCE First-line treatment of aspergillosis typically involves the use of azole antifungals. Worryingly, their future clinical use is challenged by an alarming increase in resistance. Therapeutic outcomes for such patients are poor due to delays in switching to alternative treatments and reduced efficacy of salvage therapeutics. Our lack of understanding of the molecular mechanisms that underpin resistance hampers our ability to develop novel therapeutic interventions. In this work, we dissect the regulatory motifs associated with azole resistance in the promoter of the gene that encodes the azole drug target Cyp51A. These motifs include binding platforms for SrbA and AtrR, as well as the CCAAT-binding complex and HapX. Employing mutational analyses, we uncovered crucial cyp51A-activating and -repressing functions of the binding sites. Remarkably, disrupting binding of the iron regulator HapX increased cyp51A expression and azole resistance in an iron-independent manner.
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Affiliation(s)
- Alexander Kühbacher
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Mandy Peiffer
- 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, Jena, Germany
| | - Petra Merschak
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Michael J. Bromley
- Manchester Fungal Infection Group, Division of Infection, Immunity, and Respiratory Medicine, The University of Manchester, Manchester, United Kingdom
| | - Hubertus Haas
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Axel A. Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
- Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Fabio Gsaller
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
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Differential Functions of Individual Transcription Factor Binding Sites in the Tandem Repeats Found in Clinically Relevant cyp51A Promoters in Aspergillus fumigatus. mBio 2022; 13:e0070222. [PMID: 35467427 PMCID: PMC9239056 DOI: 10.1128/mbio.00702-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Aspergillus fumigatus is the major filamentous fungal pathogen in humans. The gold standard treatment of A. fumigatus is based on azole drug use, but the appearance of azole-resistant isolates is increasing at an alarming rate. The cyp51A gene encodes the enzymatic target of azole drugs, and azole-resistant alleles of cyp51A often have an unusual genetic structure containing a duplication of a 34- or 46-bp region in the promoter causing enhanced gene transcription. These tandem repeats are called TR34 and TR46 and produce duplicated binding sites for the SrbA and AtrR transcription factors. Using site-directed mutagenesis, we demonstrate that both the SrbA (sterol response element [SRE]) and AtrR binding sites (AtrR response element [ATRE]) are required for normal cyp51A gene expression. Loss of either the SRE or ATRE from the distal 34-bp repeat of the TR34 promoter (further 5′ from the transcription start site) caused loss of expression of cyp51A and decreased voriconazole resistance. Surprisingly, loss of these same binding sites from the proximal 34- or 46-bp repeat led to increased cyp51A expression and voriconazole resistance. These data indicate that these duplicated regions in the cyp51A promoter function differently. Our findings suggest that the proximal 34- or 46-bp repeat in cyp51A recruits a corepressor that requires multiple factors to act while the distal repeat is free of this repression and provides the elevated cyp51A expression caused by these promoter duplications.
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Huber EM, Hortschansky P, Scheven MT, Misslinger M, Haas H, Brakhage AA, Groll M. Structural insights into cooperative DNA recognition by the CCAAT-binding complex and its bZIP transcription factor HapX. Structure 2022; 30:934-946.e4. [PMID: 35472306 DOI: 10.1016/j.str.2022.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 03/21/2022] [Accepted: 03/31/2022] [Indexed: 11/25/2022]
Abstract
The heterotrimeric CCAAT-binding complex (CBC) is a fundamental eukaryotic transcription factor recognizing the CCAAT box. In certain fungi, like Aspergilli, the CBC cooperates with the basic leucine zipper HapX to control iron metabolism. HapX functionally depends on the CBC, and the stable interaction of both requires DNA. To study this cooperative effect, X-ray structures of the CBC-HapX-DNA complex were determined. Downstream of the CCAAT box, occupied by the CBC, a HapX dimer binds to the major groove. The leash-like N terminus of the distal HapX subunit contacts the CBC, and via a flexible polyproline type II helix mediates minor groove interactions that stimulate sequence promiscuity. In vitro and in vivo mutagenesis suggest that the structural and functional plasticity of HapX results from local asymmetry and its ability to target major and minor grooves simultaneously. The latter feature may also apply to related transcription factors such as yeast Hap4 and distinct Yap family members.
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Affiliation(s)
- Eva M Huber
- Chair of Biochemistry, Center for Protein Assemblies, Technical University of Munich, Ernst-Otto-Fischer-Straße 8, 85748 Garching, Germany
| | - Peter Hortschansky
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (Leibniz-HKI), Adolf-Reichwein-Straße 23, 07745 Jena, Germany
| | - Mareike T Scheven
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (Leibniz-HKI), Adolf-Reichwein-Straße 23, 07745 Jena, Germany
| | - Matthias Misslinger
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Hubertus Haas
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Axel A Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (Leibniz-HKI), Adolf-Reichwein-Straße 23, 07745 Jena, Germany; Institute for Microbiology, Friedrich Schiller University Jena, Neugasse 25, 07743 Jena, Germany.
| | - Michael Groll
- Chair of Biochemistry, Center for Protein Assemblies, Technical University of Munich, Ernst-Otto-Fischer-Straße 8, 85748 Garching, Germany.
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Systematic Characterization of bZIP Transcription Factors Required for Development and Aflatoxin Generation by High-Throughput Gene Knockout in Aspergillus flavus. J Fungi (Basel) 2022; 8:jof8040356. [PMID: 35448587 PMCID: PMC9031554 DOI: 10.3390/jof8040356] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/23/2022] [Accepted: 03/23/2022] [Indexed: 12/31/2022] Open
Abstract
The basic leucine zipper (bZIP) is an important transcription factor required for fungal development, nutrient utilization, biosynthesis of secondary metabolites, and defense against various stresses. Aspergillus flavus is a major producer of aflatoxin and an opportunistic fungus on a wide range of hosts. However, little is known about the role of most bZIP genes in A. flavus. In this study, we developed a high-throughput gene knockout method based on an Agrobacterium-mediated transformation system. Gene knockout construction by yeast recombinational cloning and screening of the null mutants by double fluorescence provides an efficient way to construct gene-deleted mutants for this multinucleate fungus. We deleted 15 bZIP genes in A. flavus. Twelve of these genes were identified and characterized in this strain for the first time. The phenotypic analysis of these mutants showed that the 15 bZIP genes play a diverse role in mycelial growth (eight genes), conidiation (13 genes), aflatoxin biosynthesis (10 genes), oxidative stress response (11 genes), cell wall stress (five genes), osmotic stress (three genes), acid and alkali stress (four genes), and virulence to kernels (nine genes). Impressively, all 15 genes were involved in the development of sclerotia, and the respective deletion mutants of five of them did not produce sclerotia. Moreover, MetR was involved in this biological process. In addition, HapX and MetR play important roles in the adaptation to excessive iron and sulfur metabolism, respectively. These studies provide comprehensive insights into the role of bZIP transcription factors in this aflatoxigenic fungus of global significance.
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Genome-Wide Identification and Expression Analysis of the Basic Leucine Zipper (bZIP) Transcription Factor Gene Family in Fusarium graminearum. Genes (Basel) 2022; 13:genes13040607. [PMID: 35456413 PMCID: PMC9028111 DOI: 10.3390/genes13040607] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 03/18/2022] [Accepted: 03/26/2022] [Indexed: 12/14/2022] Open
Abstract
The basic leucine zipper (bZIP) is a widely found transcription factor family that plays regulatory roles in a variety of cellular processes including cell growth and development and various stress responses. However, the bZIP gene family has not been well studied at a genome-wide scale in Fusarium graminearum (Fg), a potent pathogen of cereal grains. In the present study, we conducted a genome-wide identification, characterization, and expression profiling of 22 F. graminearum bZIP (FgbZIP) genes at different developmental stages and under various abiotic stresses. All identified FgbZIPs were categorized into nine groups based on their sequence similarity and phylogenetic tree analysis. Furthermore, the gene structure analysis, conserved motif analysis, chromosomal localization, protein network studies, and synteny analysis were performed. The symmetry of the exon and intron varied with the phylogenetic groups. The post-translational modifications (PTMs) analysis also predicted several phosphorylation sites in FgbZIPs, indicating their functional diversity in cellular processes. The evolutionary study identified many orthogroups among eight species and also predicted several gene duplication events in F. graminearum. The protein modeling indicated the presence of a higher number of α-helices and random coils in their structures. The expression patterns of FgbZIP genes showed that 5 FgbZIP genes, including FgbZIP_1.1, FgbZIP_1.3, FgbZIP_2.6 FgbZIP_3.1 and FgbZIP_4.3, had high expression at different growth and conidiogenesis stages. Similarly, eight genes including FgbZIP_1.1, FgbZIP_1.6, FgbZIP_2.3, FgbZIP_2.4, FgbZIP_4.1, FgbZIP_4.2, FgbZIP_4.3 and FgbZIP_4.6 demonstrated their putative role in response to various abiotic stresses. In summary, these results provided basic information regarding FgbZIPs which are helpful for further functional analysis.
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Delaveau T, Thiébaut A, Benchouaia M, Merhej J, Devaux F. Yap5 Competes With Hap4 for the Regulation of Iron Homeostasis Genes in the Human Pathogen Candida glabrata. Front Cell Infect Microbiol 2021; 11:731988. [PMID: 34900750 PMCID: PMC8662346 DOI: 10.3389/fcimb.2021.731988] [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] [Received: 06/28/2021] [Accepted: 11/10/2021] [Indexed: 11/18/2022] Open
Abstract
The CCAAT-binding complex (CBC) is a conserved heterotrimeric transcription factor which, in fungi, requires additional regulatory subunits to act on transcription. In the pathogenic yeast Candida glabrata, CBC has a dual role. Together with the Hap4 regulatory subunit, it activates the expression of genes involved in respiration upon growth with non-fermentable carbon sources, while its association with the Yap5 regulatory subunit is required for the activation of iron tolerance genes in response to iron excess. In the present work, we investigated further the interplay between CBC, Hap4 and Yap5. We showed that Yap5 regulation requires a specific Yap Response Element in the promoter of its target gene GRX4 and that the presence of Yap5 considerably strengthens the binding of CBC to the promoters of iron tolerance genes. Chromatin immunoprecipitation (ChIP) and transcriptome experiments showed that Hap4 can also bind these promoters but has no impact on the expression of those genes when Yap5 is present. In the absence of Yap5 however, GRX4 is constitutively regulated by Hap4, similarly to the genes involved in respiration. Our results suggest that the distinction between the two types of CBC targets in C. glabrata is mainly due to the dependency of Yap5 for very specific DNA sequences and to the competition between Hap4 and Yap5 at the promoter of the iron tolerance genes.
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Affiliation(s)
- Thierry Delaveau
- Sorbonne Université, CNRS, Institut de biologie Paris-Seine (IBPS), UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative, Paris, France
| | - Antonin Thiébaut
- Sorbonne Université, CNRS, Institut de biologie Paris-Seine (IBPS), UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative, Paris, France
| | - Médine Benchouaia
- Sorbonne Université, CNRS, Institut de biologie Paris-Seine (IBPS), UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative, Paris, France
| | - Jawad Merhej
- Sorbonne Université, CNRS, Institut de biologie Paris-Seine (IBPS), UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative, Paris, France
| | - Frédéric Devaux
- Sorbonne Université, CNRS, Institut de biologie Paris-Seine (IBPS), UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative, Paris, France
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Arastehfar A, Carvalho A, Houbraken J, Lombardi L, Garcia-Rubio R, Jenks J, Rivero-Menendez O, Aljohani R, Jacobsen I, Berman J, Osherov N, Hedayati M, Ilkit M, Armstrong-James D, Gabaldón T, Meletiadis J, Kostrzewa M, Pan W, Lass-Flörl C, Perlin D, Hoenigl M. Aspergillus fumigatus and aspergillosis: From basics to clinics. Stud Mycol 2021; 100:100115. [PMID: 34035866 PMCID: PMC8131930 DOI: 10.1016/j.simyco.2021.100115] [Citation(s) in RCA: 87] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The airborne fungus Aspergillus fumigatus poses a serious health threat to humans by causing numerous invasive infections and a notable mortality in humans, especially in immunocompromised patients. Mould-active azoles are the frontline therapeutics employed to treat aspergillosis. The global emergence of azole-resistant A. fumigatus isolates in clinic and environment, however, notoriously limits the therapeutic options of mould-active antifungals and potentially can be attributed to a mortality rate reaching up to 100 %. Although specific mutations in CYP 51A are the main cause of azole resistance, there is a new wave of azole-resistant isolates with wild-type CYP 51A genotype challenging the efficacy of the current diagnostic tools. Therefore, applications of whole-genome sequencing are increasingly gaining popularity to overcome such challenges. Prominent echinocandin tolerance, as well as liver and kidney toxicity posed by amphotericin B, necessitate a continuous quest for novel antifungal drugs to combat emerging azole-resistant A. fumigatus isolates. Animal models and the tools used for genetic engineering require further refinement to facilitate a better understanding about the resistance mechanisms, virulence, and immune reactions orchestrated against A. fumigatus. This review paper comprehensively discusses the current clinical challenges caused by A. fumigatus and provides insights on how to address them.
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Affiliation(s)
- A. Arastehfar
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA
| | - A. Carvalho
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B's - PT Government Associate Laboratory, Guimarães/Braga, Portugal
| | - J. Houbraken
- Westerdijk Fungal Biodiversity Institute, Utrecht, the Netherlands
| | - L. Lombardi
- UCD Conway Institute and School of Medicine, University College Dublin, Dublin 4, Ireland
| | - R. Garcia-Rubio
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA
| | - J.D. Jenks
- Department of Medicine, University of California San Diego, San Diego, CA, 92103, USA
- Clinical and Translational Fungal-Working Group, University of California San Diego, La Jolla, CA, 92093, USA
| | - O. Rivero-Menendez
- Medical Mycology Reference Laboratory, National Center for Microbiology, Instituto de Salud Carlos III, Madrid, 28222, Spain
| | - R. Aljohani
- Department of Infectious Diseases, Imperial College London, London, UK
| | - I.D. Jacobsen
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology—Hans Knöll Institute, Jena, Germany
- Institute for Microbiology, Friedrich Schiller University, Jena, Germany
| | - J. Berman
- Research Group Microbial Immunology, Leibniz Institute for Natural Product Research and Infection Biology—Hans Knöll Institute, Jena, Germany
| | - N. Osherov
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel-Aviv, 69978, Israel
| | - M.T. Hedayati
- Invasive Fungi Research Center/Department of Medical Mycology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - M. Ilkit
- Division of Mycology, Department of Microbiology, Faculty of Medicine, Çukurova University, 01330, Adana, Turkey
| | | | - T. Gabaldón
- Life Sciences Programme, Supercomputing Center (BSC-CNS), Jordi Girona, Barcelona, 08034, Spain
- Mechanisms of Disease Programme, Institute for Research in Biomedicine (IRB), Barcelona, Spain
- ICREA, Pg. Lluís Companys 23, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Pg. Lluís Companys 23, 08010, Barcelona, Spain
| | - J. Meletiadis
- Clinical Microbiology Laboratory, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | | | - W. Pan
- Medical Mycology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
| | - C. Lass-Flörl
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - D.S. Perlin
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, 07110, USA
| | - M. Hoenigl
- Department of Medicine, University of California San Diego, San Diego, CA, 92103, USA
- Section of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Medical University of Graz, 8036, Graz, Austria
- Division of Infectious Diseases and Global Public Health, Department of Medicine, University of California San Diego, San Diego, CA 92093, USA
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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: 59] [Impact Index Per Article: 14.8] [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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Furukawa T, Scheven MT, Misslinger M, Zhao C, Hoefgen S, Gsaller F, Lau J, Jöchl C, Donaldson I, Valiante V, Brakhage AA, Bromley MJ, Haas H, Hortschansky P. The fungal CCAAT-binding complex and HapX display highly variable but evolutionary conserved synergetic promoter-specific DNA recognition. Nucleic Acids Res 2020; 48:3567-3590. [PMID: 32086516 PMCID: PMC7144946 DOI: 10.1093/nar/gkaa109] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 02/07/2020] [Accepted: 02/18/2020] [Indexed: 12/13/2022] Open
Abstract
To sustain iron homeostasis, microorganisms have evolved fine-tuned mechanisms for uptake, storage and detoxification of the essential metal iron. In the human pathogen Aspergillus fumigatus, the fungal-specific bZIP-type transcription factor HapX coordinates adaption to both iron starvation and iron excess and is thereby crucial for virulence. Previous studies indicated that a HapX homodimer interacts with the CCAAT-binding complex (CBC) to cooperatively bind bipartite DNA motifs; however, the mode of HapX-DNA recognition had not been resolved. Here, combination of in vivo (genetics and ChIP-seq), in vitro (surface plasmon resonance) and phylogenetic analyses identified an astonishing plasticity of CBC:HapX:DNA interaction. DNA motifs recognized by the CBC:HapX protein complex comprise a bipartite DNA binding site 5′-CSAATN12RWT-3′ and an additional 5′-TKAN-3′ motif positioned 11–23 bp downstream of the CCAAT motif, i.e. occasionally overlapping the 3′-end of the bipartite binding site. Phylogenetic comparison taking advantage of 20 resolved Aspergillus species genomes revealed that DNA recognition by the CBC:HapX complex shows promoter-specific cross-species conservation rather than regulon-specific conservation. Moreover, we show that CBC:HapX interaction is absolutely required for all known functions of HapX. The plasticity of the CBC:HapX:DNA interaction permits fine tuning of CBC:HapX binding specificities that could support adaptation of pathogens to their host niches.
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Affiliation(s)
- Takanori Furukawa
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester M13 9PL, UK
| | - Mareike Thea Scheven
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena D-07745, Germany
| | - Matthias Misslinger
- Division of Molecular Biology/Biocenter, Innsbruck Medical University, Innsbruck, A-6020, Austria
| | - Can Zhao
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester M13 9PL, UK
| | - Sandra Hoefgen
- Leibniz Research Group Biobricks of Microbial Natural Product Syntheses, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena D-07745, Germany
| | - Fabio Gsaller
- Division of Molecular Biology/Biocenter, Innsbruck Medical University, Innsbruck, A-6020, Austria
| | - Jeffrey Lau
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester M13 9PL, UK
| | - Christoph Jöchl
- Division of Molecular Biology/Biocenter, Innsbruck Medical University, Innsbruck, A-6020, Austria
| | - Ian Donaldson
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester M13 9PL, UK
| | - Vito Valiante
- Leibniz Research Group Biobricks of Microbial Natural Product Syntheses, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena D-07745, Germany.,Friedrich Schiller University Jena, Jena D-07745, Germany
| | - Axel A Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena D-07745, Germany.,Friedrich Schiller University Jena, Jena D-07745, Germany
| | - Michael J Bromley
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester M13 9PL, UK
| | - Hubertus Haas
- Division of Molecular Biology/Biocenter, Innsbruck Medical University, Innsbruck, A-6020, Austria
| | - Peter Hortschansky
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena D-07745, Germany
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12
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Hortschansky P, Misslinger M, Mörl J, Gsaller F, Bromley MJ, Brakhage AA, Groll M, Haas H, Huber EM. Structural basis of HapE P88L-linked antifungal triazole resistance in Aspergillus fumigatus. Life Sci Alliance 2020; 3:3/7/e202000729. [PMID: 32467317 PMCID: PMC7266990 DOI: 10.26508/lsa.202000729] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 05/08/2020] [Accepted: 05/12/2020] [Indexed: 01/27/2023] Open
Abstract
Azoles are first-line therapeutics for human and plant fungal infections, but their broad use has promoted the development of resistances. Recently, a pan-azole-resistant clinical Aspergillus fumigatus isolate was identified to carry the mutation P88L in subunit HapE of the CCAAT-binding complex (CBC), a conserved eukaryotic transcription factor. Here, we define the mechanistic basis for resistance in this isolate by showing that the HapEP88L mutation interferes with the CBC's ability to bend and sense CCAAT motifs. This failure leads to transcriptional derepression of the cyp51A gene, which encodes the target of azoles, the 14-α sterol demethylase Cyp51A, and ultimately causes drug resistance. In addition, we demonstrate that the CBC-associated transcriptional regulator HapX assists cyp51A repression in low-iron environments and that this iron-dependent effect is lost in the HapEP88L mutant. Altogether, these results indicate that the mutation HapEP88L confers increased resistance to azoles compared with wt A. fumigatus, particularly in low-iron clinical niches such as the lung.
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Affiliation(s)
- Peter Hortschansky
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), and Friedrich Schiller University Jena, Jena, Germany
| | - Matthias Misslinger
- Institute of Molecular Biology/Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Jasmin Mörl
- Institute of Molecular Biology/Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Fabio Gsaller
- Institute of Molecular Biology/Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Michael J Bromley
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester, UK
| | - Axel A Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), and Friedrich Schiller University Jena, Jena, Germany
| | - Michael Groll
- Center for Integrated Protein Science Munich at the Department Chemistry, Technical University of Munich, Garching, Germany
| | - Hubertus Haas
- Institute of Molecular Biology/Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Eva M Huber
- Center for Integrated Protein Science Munich at the Department Chemistry, Technical University of Munich, Garching, Germany
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13
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Pogenberg V, Ballesteros-Álvarez J, Schober R, Sigvaldadóttir I, Obarska-Kosinska A, Milewski M, Schindl R, Ögmundsdóttir MH, Steingrímsson E, Wilmanns M. Mechanism of conditional partner selectivity in MITF/TFE family transcription factors with a conserved coiled coil stammer motif. Nucleic Acids Res 2020; 48:934-948. [PMID: 31777941 PMCID: PMC6954422 DOI: 10.1093/nar/gkz1104] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 11/01/2019] [Accepted: 11/25/2019] [Indexed: 12/01/2022] Open
Abstract
Interrupted dimeric coiled coil segments are found in a broad range of proteins and generally confer selective functional properties such as binding to specific ligands. However, there is only one documented case of a basic-helix–loop–helix leucine zipper transcription factor—microphthalmia-associated transcription factor (MITF)—in which an insertion of a three-residue stammer serves as a determinant of conditional partner selectivity. To unravel the molecular principles of this selectivity, we have analyzed the high-resolution structures of stammer-containing MITF and an engineered stammer-less MITF variant, which comprises an uninterrupted symmetric coiled coil. Despite this fundamental difference, both MITF structures reveal identical flanking in-phase coiled coil arrangements, gained by helical over-winding and local asymmetry in wild-type MITF across the stammer region. These conserved structural properties allow the maintenance of a proper functional readout in terms of nuclear localization and binding to specific DNA-response motifs regardless of the presence of the stammer. By contrast, MITF heterodimer formation with other bHLH-Zip transcription factors is only permissive when both factors contain either the same type of inserted stammer or no insert. Our data illustrate a unique principle of conditional partner selectivity within the wide arsenal of transcription factors with specific partner-dependent functional readouts.
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Affiliation(s)
| | - Josué Ballesteros-Álvarez
- Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Sturlugata 8, 101 Reykjavik, Iceland
| | - Romana Schober
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Gruberstraße 40, A-4020 Linz, Austria
| | - Ingibjörg Sigvaldadóttir
- Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Sturlugata 8, 101 Reykjavik, Iceland
| | - Agnieszka Obarska-Kosinska
- EMBL Hamburg c/o DESY, Notkestraße 85, 22607 Hamburg, Germany.,Max Planck Institute of Biophysics, Max-von-Laue-Straße 3, 60438 Frankfurt am Main, Germany
| | - Morlin Milewski
- EMBL Hamburg c/o DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - Rainer Schindl
- Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstrasse 6, A-8010 Graz, Austria
| | - Margrét Helga Ögmundsdóttir
- Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Sturlugata 8, 101 Reykjavik, Iceland
| | - Eiríkur Steingrímsson
- Department of Biochemistry and Molecular Biology, BioMedical Center, Faculty of Medicine, University of Iceland, Sturlugata 8, 101 Reykjavik, Iceland
| | - Matthias Wilmanns
- EMBL Hamburg c/o DESY, Notkestraße 85, 22607 Hamburg, Germany.,University Hamburg Clinical Centre Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany
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14
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Jin X, Hapsari ND, Lee S, Jo K. DNA binding fluorescent proteins as single-molecule probes. Analyst 2020; 145:4079-4095. [DOI: 10.1039/d0an00218f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
DNA binding fluorescent proteins are useful probes for a broad range of biological applications.
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Affiliation(s)
- Xuelin Jin
- Department of Chemistry and Interdisciplinary Program of Integrated Biotechnology
- Sogang University
- Seoul
- Republic of Korea
| | - Natalia Diyah Hapsari
- Department of Chemistry and Interdisciplinary Program of Integrated Biotechnology
- Sogang University
- Seoul
- Republic of Korea
- Chemistry Education Program
| | - Seonghyun Lee
- Department of Chemistry and Interdisciplinary Program of Integrated Biotechnology
- Sogang University
- Seoul
- Republic of Korea
| | - Kyubong Jo
- Department of Chemistry and Interdisciplinary Program of Integrated Biotechnology
- Sogang University
- Seoul
- Republic of Korea
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15
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Ghosh RP, Shi Q, Yang L, Reddick MP, Nikitina T, Zhurkin VB, Fordyce P, Stasevich TJ, Chang HY, Greenleaf WJ, Liphardt JT. Satb1 integrates DNA binding site geometry and torsional stress to differentially target nucleosome-dense regions. Nat Commun 2019; 10:3221. [PMID: 31324780 PMCID: PMC6642133 DOI: 10.1038/s41467-019-11118-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 06/20/2019] [Indexed: 01/12/2023] Open
Abstract
The Satb1 genome organizer regulates multiple cellular and developmental processes. It is not yet clear how Satb1 selects different sets of targets throughout the genome. Here we have used live-cell single molecule imaging and deep sequencing to assess determinants of Satb1 binding-site selectivity. We have found that Satb1 preferentially targets nucleosome-dense regions and can directly bind consensus motifs within nucleosomes. Some genomic regions harbor multiple, regularly spaced Satb1 binding motifs (typical separation ~1 turn of the DNA helix) characterized by highly cooperative binding. The Satb1 homeodomain is dispensable for high affinity binding but is essential for specificity. Finally, we find that Satb1-DNA interactions are mechanosensitive. Increasing negative torsional stress in DNA enhances Satb1 binding and Satb1 stabilizes base unpairing regions against melting by molecular machines. The ability of Satb1 to control diverse biological programs may reflect its ability to combinatorially use multiple site selection criteria.
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Affiliation(s)
- Rajarshi P Ghosh
- Bioengineering, Stanford University, Stanford, CA, 94305, USA
- BioX Institute, Stanford University, Stanford, CA, 94305, USA
- ChEM-H, Stanford University, Stanford, CA, 94305, USA
- Cell Biology Division, Stanford Cancer Institute, Stanford, CA, 94305, USA
| | - Quanming Shi
- Bioengineering, Stanford University, Stanford, CA, 94305, USA
- BioX Institute, Stanford University, Stanford, CA, 94305, USA
- ChEM-H, Stanford University, Stanford, CA, 94305, USA
- Cell Biology Division, Stanford Cancer Institute, Stanford, CA, 94305, USA
| | - Linfeng Yang
- Bioengineering, Stanford University, Stanford, CA, 94305, USA
- BioX Institute, Stanford University, Stanford, CA, 94305, USA
- ChEM-H, Stanford University, Stanford, CA, 94305, USA
- Cell Biology Division, Stanford Cancer Institute, Stanford, CA, 94305, USA
| | - Michael P Reddick
- Bioengineering, Stanford University, Stanford, CA, 94305, USA
- BioX Institute, Stanford University, Stanford, CA, 94305, USA
- ChEM-H, Stanford University, Stanford, CA, 94305, USA
- Cell Biology Division, Stanford Cancer Institute, Stanford, CA, 94305, USA
- Chemical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Tatiana Nikitina
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Victor B Zhurkin
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Polly Fordyce
- Bioengineering, Stanford University, Stanford, CA, 94305, USA
- ChEM-H, Stanford University, Stanford, CA, 94305, USA
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA
- Chan Zuckerberg Biohub, San Francisco, CA, 94158, USA
| | - Timothy J Stasevich
- Department of Biochemistry and Molecular Biology and the Institute for Genome Architecture and Function, Colorado State University, Fort Collins, CO, USA
| | - Howard Y Chang
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA
- Center for Personal Dynamic Regulomes, Stanford University, Stanford, CA, 94305, USA
- Program in Epithelial Biology, Stanford University School of Medicine, Stanford, CA, 94305, USA
- Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
| | - William J Greenleaf
- Department of Genetics, Stanford University, Stanford, CA, 94305, USA
- Department of Applied Physics, Stanford University, Stanford, United States
| | - Jan T Liphardt
- Bioengineering, Stanford University, Stanford, CA, 94305, USA.
- BioX Institute, Stanford University, Stanford, CA, 94305, USA.
- ChEM-H, Stanford University, Stanford, CA, 94305, USA.
- Cell Biology Division, Stanford Cancer Institute, Stanford, CA, 94305, USA.
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16
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Rodrigues-Pousada C, Devaux F, Caetano SM, Pimentel C, da Silva S, Cordeiro AC, Amaral C. Yeast AP-1 like transcription factors (Yap) and stress response: a current overview. MICROBIAL CELL 2019; 6:267-285. [PMID: 31172012 PMCID: PMC6545440 DOI: 10.15698/mic2019.06.679] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Yeast adaptation to stress has been extensively studied. It involves large reprogramming of genome expression operated by many, more or less specific, transcription factors. Here, we review our current knowledge on the function of the eight Yap transcription factors (Yap1 to Yap8) in Saccharomyces cerevisiae, which were shown to be involved in various stress responses. More precisely, Yap1 is activated under oxidative stress, Yap2/Cad1 under cadmium, Yap4/Cin5 and Yap6 under osmotic shock, Yap5 under iron overload and Yap8/Arr1 by arsenic compounds. Yap3 and Yap7 seem to be involved in hydroquinone and nitrosative stresses, respectively. The data presented in this article illustrate how much knowledge on the function of these Yap transcription factors is advanced. The evolution of the Yap family and its roles in various pathogenic and non-pathogenic fungal species is discussed in the last section.
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Affiliation(s)
- Claudina Rodrigues-Pousada
- Instituto de Tecnologia Química e Biológica Anónio Xavier, Universidade Nova de Lisboa, Avenida da República, EAN, Oeiras 2781-901, Oeiras, Portugal
| | - Frédéric Devaux
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, F-75005, Paris, France
| | - Soraia M Caetano
- Instituto de Tecnologia Química e Biológica Anónio Xavier, Universidade Nova de Lisboa, Avenida da República, EAN, Oeiras 2781-901, Oeiras, Portugal
| | - Catarina Pimentel
- Instituto de Tecnologia Química e Biológica Anónio Xavier, Universidade Nova de Lisboa, Avenida da República, EAN, Oeiras 2781-901, Oeiras, Portugal
| | - Sofia da Silva
- Instituto de Tecnologia Química e Biológica Anónio Xavier, Universidade Nova de Lisboa, Avenida da República, EAN, Oeiras 2781-901, Oeiras, Portugal
| | - Ana Carolina Cordeiro
- Instituto de Tecnologia Química e Biológica Anónio Xavier, Universidade Nova de Lisboa, Avenida da República, EAN, Oeiras 2781-901, Oeiras, Portugal
| | - Catarina Amaral
- Instituto de Tecnologia Química e Biológica Anónio Xavier, Universidade Nova de Lisboa, Avenida da República, EAN, Oeiras 2781-901, Oeiras, Portugal
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17
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Devaux F, Thiébaut A. The regulation of iron homeostasis in the fungal human pathogen Candida glabrata. MICROBIOLOGY-SGM 2019; 165:1041-1060. [PMID: 31050635 DOI: 10.1099/mic.0.000807] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Iron is an essential element to most microorganisms, yet an excess of iron is toxic. Hence, living cells have to maintain a tight balance between iron uptake and iron consumption and storage. The control of intracellular iron concentrations is particularly challenging for pathogens because mammalian organisms have evolved sophisticated high-affinity systems to sequester iron from microbes and because iron availability fluctuates among the different host niches. In this review, we present the current understanding of iron homeostasis and its regulation in the fungal pathogen Candida glabrata. This yeast is an emerging pathogen which has become the second leading cause of candidemia, a life-threatening invasive mycosis. C. glabrata is relatively poorly studied compared to the closely related model yeast Saccharomyces cerevisiae or to the pathogenic yeast Candida albicans. Still, several research groups have started to identify the actors of C. glabrata iron homeostasis and its transcriptional and post-transcriptional regulation. These studies have revealed interesting particularities of C. glabrata and have shed new light on the evolution of fungal iron homeostasis.
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Affiliation(s)
- Frédéric Devaux
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, F-75005, Paris, France
| | - Antonin Thiébaut
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, F-75005, Paris, France
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18
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Vicentefranqueira R, Leal F, Marín L, Sánchez CI, Calera JA. The interplay between zinc and iron homeostasis in
Aspergillus fumigatus
under zinc‐replete conditions relies on the iron‐mediated regulation of alternative transcription units of
zafA
and the basal amount of the ZafA zinc‐responsiveness transcription factor. Environ Microbiol 2019; 21:2787-2808. [DOI: 10.1111/1462-2920.14618] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 04/03/2019] [Indexed: 12/27/2022]
Affiliation(s)
- Rocío Vicentefranqueira
- Instituto de Biología Funcional y Genómica (IBFG‐CSIC)Universidad de Salamanca Salamanca Spain
| | - Fernando Leal
- Instituto de Biología Funcional y Genómica (IBFG‐CSIC)Universidad de Salamanca Salamanca Spain
- Departamento de Microbiología y GenéticaUniversidad de Salamanca Salamanca Spain
| | - Laura Marín
- Instituto de Biología Funcional y Genómica (IBFG‐CSIC)Universidad de Salamanca Salamanca Spain
| | - Clara Inés Sánchez
- Instituto de Biología Funcional y Genómica (IBFG‐CSIC)Universidad de Salamanca Salamanca Spain
| | - José Antonio Calera
- Instituto de Biología Funcional y Genómica (IBFG‐CSIC)Universidad de Salamanca Salamanca Spain
- Departamento de Microbiología y GenéticaUniversidad de Salamanca Salamanca Spain
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19
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Lu Y, Liu G, Jiang H, Chi Z, Chi Z. An insight into the iron acquisition and homeostasis in Aureobasidium melanogenum HN6.2 strain through genome mining and transcriptome analysis. Funct Integr Genomics 2018; 19:137-150. [PMID: 30251029 DOI: 10.1007/s10142-018-0633-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 08/07/2018] [Accepted: 08/23/2018] [Indexed: 11/26/2022]
Abstract
Aureobasidium melanogenum HN6.2 is a unique yeast strain who can produce the siderophore of fusigen under iron starvation to guarantee its survival. However, a comprehensive understanding of mechanisms involved in iron acquisition and homeostasis for it is still vacant. In this study, genome sequencing and mining revealed that A. melanogenum HN6.2 strain was the first yeast species that exclusively possessed all the four known mechanisms for the iron acquisition: (i) the siderophore-mediated iron uptake; (ii) reductive iron assimilation; (iii) low-affinity ferrous uptake; and (iv) heme utilization, which suggested its stronger adaptability than Aspergillus fumigatus and Saccharomyces cerevisiae. This HN6.2 strain also employed the vacuolar iron storage for immobilizing the excessive iron to avoid its cellular toxicity. Specially, genome mining indicated that A. melanogenum HN6.2 strain could also synthesize ferricrocin siderophore. Further HPLC and Q-Tof-MS analysis confirmed that the siderophores synthesized by this strain consisted of cyclic fusigen, linear fusigen, ferricrocin, and hydroxyferricrocin and they played parallel roles as both intracellular and extracellular siderophores. Also, the heme utilization for this strain was experimentally verified by the knock-out of heme oxygenase gene. For iron homeostasis, the transcriptome analysis revealed that this strain mainly employed two central regulators of SreA/HapX to tune iron uptake and storage at the transcriptional level. It was also noted that mitogen-activated protein kinase C gene (MpkC) exhibited a transcriptional up-regulation under iron sufficiency, suggesting that it may serve as another factor involved in the repression of siderophore biosynthesis. This is the first genetic blueprint of iron acquisition and homeostasis for A. melanogenum.
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Affiliation(s)
- Yi Lu
- College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
| | - Guanglei Liu
- College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
| | - Hong Jiang
- College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
| | - Zhenming Chi
- College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
- Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, 266003, China
| | - Zhe Chi
- College of Marine Life Science, Ocean University of China, Qingdao, 266003, China.
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20
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The CCAAT-Binding Complex Controls Respiratory Gene Expression and Iron Homeostasis in Candida Glabrata. Sci Rep 2017; 7:3531. [PMID: 28615656 PMCID: PMC5471220 DOI: 10.1038/s41598-017-03750-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 04/20/2017] [Indexed: 12/04/2022] Open
Abstract
The CCAAT-binding complex (CBC) is a heterotrimeric transcription factor which is widely conserved in eukaryotes. In the model yeast S. cerevisiae, CBC positively controls the expression of respiratory pathway genes. This role involves interactions with the regulatory subunit Hap4. In many pathogenic fungi, CBC interacts with the HapX regulatory subunit to control iron homeostasis. HapX is a bZIP protein which only shares with Hap4 the Hap4Like domain (Hap4L) required for its interaction with CBC. Here, we show that CBC has a dual role in the pathogenic yeast C. glabrata. It is required, along with Hap4, for the constitutive expression of respiratory genes and it is also essential for the iron stress response, which is mediated by the Yap5 bZIP transcription factor. Interestingly, Yap5 contains a vestigial Hap4L domain. The mutagenesis of this domain severely reduced Yap5 binding to its targets and compromised its interaction with Hap5. Hence, Yap5, like HapX in other species, acts as a CBC regulatory subunit in the regulation of iron stress response. This work reveals new aspects of iron homeostasis in C. glabrata and of the evolution of the role of CBC and Hap4L-bZIP proteins in this process.
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21
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Dhingra S, Cramer RA. Regulation of Sterol Biosynthesis in the Human Fungal Pathogen Aspergillus fumigatus: Opportunities for Therapeutic Development. Front Microbiol 2017; 8:92. [PMID: 28203225 PMCID: PMC5285346 DOI: 10.3389/fmicb.2017.00092] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 01/13/2017] [Indexed: 12/29/2022] Open
Abstract
Sterols are a major component of eukaryotic cell membranes. For human fungal infections caused by the filamentous fungus Aspergillus fumigatus, antifungal drugs that target sterol biosynthesis and/or function remain the standard of care. Yet, an understanding of A. fumigatus sterol biosynthesis regulatory mechanisms remains an under developed therapeutic target. The critical role of sterol biosynthesis regulation and its interactions with clinically relevant azole drugs is highlighted by the basic helix loop helix (bHLH) class of transcription factors known as Sterol Regulatory Element Binding Proteins (SREBPs). SREBPs regulate transcription of key ergosterol biosynthesis genes in fungi including A. fumigatus. In addition, other emerging regulatory pathways and target genes involved in sterol biosynthesis and drug interactions provide additional opportunities including the unfolded protein response, iron responsive transcriptional networks, and chaperone proteins such as Hsp90. Thus, targeting molecular pathways critical for sterol biosynthesis regulation presents an opportunity to improve therapeutic options for the collection of diseases termed aspergillosis. This mini-review summarizes our current understanding of sterol biosynthesis regulation with a focus on mechanisms of transcriptional regulation by the SREBP family of transcription factors.
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Affiliation(s)
- Sourabh Dhingra
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover NH, USA
| | - Robert A Cramer
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover NH, USA
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22
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Hortschansky P, Haas H, Huber EM, Groll M, Brakhage AA. The CCAAT-binding complex (CBC) in Aspergillus species. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2016; 1860:560-570. [PMID: 27939757 DOI: 10.1016/j.bbagrm.2016.11.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 11/25/2016] [Accepted: 11/26/2016] [Indexed: 11/30/2022]
Abstract
BACKGROUND The CCAAT binding complex (CBC), consisting of a heterotrimeric core structure, is highly conserved in eukaryotes and constitutes an important general transcriptional regulator. Scope of the review. In this review we discuss the scientific history and the current state of knowledge of the multiple gene regulatory functions, protein motifs and structure of the CBC in fungi with a special focus on Aspergillus species. Major conclusions and general significance. Initially identified as a transcriptional activator of respiration in Saccharomyces cerevisiae, in other fungal species the CBC was found to be involved in highly diverse pathways, but a general rationale for its involvement was missing. Subsequently, the CBC was found to sense reactive oxygen species through oxidative modifications of cysteine residues in order to mediate redox regulation. Moreover, via interaction with the iron-sensing bZIP transcription factor HapX, the CBC was shown to mediate adaptation to both iron starvation and iron excess. Due to the control of various pathways in primary and secondary metabolism the CBC is of crucial importance for fungal virulence in both animal and plant hosts as well as antifungal resistance. Consequently, CBC-mediated control affects biological processes that are of high interest in biotechnology, agriculture and infection medicine. This article is part of a Special Issue entitled: Nuclear Factor Y in Development and Disease, edited by Prof. Roberto Mantovani.
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Affiliation(s)
- Peter Hortschansky
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstr. 11a, D-07745, Jena, Germany
| | - Hubertus Haas
- Division of Molecular Biology, Biocenter, Medical University of Innsbruck, Innrain 80-82, A6020 Innsbruck, Austria
| | - Eva M Huber
- Center for Integrated Protein Science Munich at the Department Chemistry, Technische Universität München, Lichtenbergstr. 4, D-85748, Garching, Germany
| | - Michael Groll
- Center for Integrated Protein Science Munich at the Department Chemistry, Technische Universität München, Lichtenbergstr. 4, D-85748, Garching, Germany
| | - Axel A Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstr. 11a, D-07745, Jena, Germany; Department of Microbiology and Molecular Biology, Friedrich Schiller University (FSU), D-07745 Jena, Germany.
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23
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Gsaller F, Hortschansky P, Furukawa T, Carr PD, Rash B, Capilla J, Müller C, Bracher F, Bowyer P, Haas H, Brakhage AA, Bromley MJ. Sterol Biosynthesis and Azole Tolerance Is Governed by the Opposing Actions of SrbA and the CCAAT Binding Complex. PLoS Pathog 2016; 12:e1005775. [PMID: 27438727 PMCID: PMC4954732 DOI: 10.1371/journal.ppat.1005775] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Accepted: 06/28/2016] [Indexed: 02/01/2023] Open
Abstract
Azole drugs selectively target fungal sterol biosynthesis and are critical to our antifungal therapeutic arsenal. However, resistance to this class of drugs, particularly in the major human mould pathogen Aspergillus fumigatus, is emerging and reaching levels that have prompted some to suggest that there is a realistic probability that they will be lost for clinical use. The dominating class of pan-azole resistant isolates is characterized by the presence of a tandem repeat of at least 34 bases (TR34) within the promoter of cyp51A, the gene encoding the azole drug target sterol C14-demethylase. Here we demonstrate that the repeat sequence in TR34 is bound by both the sterol regulatory element binding protein (SREBP) SrbA, and the CCAAT binding complex (CBC). We show that the CBC acts complementary to SrbA as a negative regulator of ergosterol biosynthesis and show that lack of CBC activity results in increased sterol levels via transcriptional derepression of multiple ergosterol biosynthetic genes including those coding for HMG-CoA-synthase, HMG-CoA-reductase and sterol C14-demethylase. In agreement with these findings, inactivation of the CBC increased tolerance to different classes of drugs targeting ergosterol biosynthesis including the azoles, allylamines (terbinafine) and statins (simvastatin). We reveal that a clinically relevant mutation in HapE (P88L) significantly impairs the binding affinity of the CBC to its target site. We identify that the mechanism underpinning TR34 driven overexpression of cyp51A results from duplication of SrbA but not CBC binding sites and show that deletion of the 34 mer results in lack of cyp51A expression and increased azole susceptibility similar to a cyp51A null mutant. Finally we show that strains lacking a functional CBC are severely attenuated for pathogenicity in a pulmonary and systemic model of aspergillosis. Aspergillus fumigatus is the most important airborne mould pathogen and allergen worldwide. Estimates suggest that >3 million people have invasive or chronic infections that lead to >600,000 deaths every year. Very few drugs are available to treat the various forms of aspergillosis and we rely predominantly on the azole class of agents which inhibit sterol biosynthesis. Resistance to the azoles is growing alarmingly, primarily driven by strains with two principal genetic signatures (TR34/L98H and TR46/Y121F/T289A). In this study we identify that the transcriptional mechanism governing resistance in this group of isolates is linked to the opposing actions of 2 transcriptional regulators, SrbA and the CBC, and uncover a role for the CBC in sterol regulation and virulence in A. fumigatus. We propose targeting SrbA would provide an effective avenue for therapeutic intervention for resistant strains.
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Affiliation(s)
- Fabio Gsaller
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester, United Kingdom
| | - Peter Hortschansky
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany
| | - Takanori Furukawa
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester, United Kingdom
| | - Paul D. Carr
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester, United Kingdom
| | - Bharat Rash
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester, United Kingdom
| | - Javier Capilla
- Microbiology Unit, Medical School, Universitat Rovira i Virgili, Reus, Spain
| | - Christoph Müller
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians University of Munich, Munich, Germany
| | - Franz Bracher
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians University of Munich, Munich, Germany
| | - Paul Bowyer
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester, United Kingdom
| | - Hubertus Haas
- Division of Molecular Biology, Biocentre, Medical University of Innsbruck, Innsbruck, Austria
| | - Axel A. Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany
- Institute for Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Michael J. Bromley
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, University of Manchester, Manchester, United Kingdom
- * E-mail:
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24
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Merhej J, Thiebaut A, Blugeon C, Pouch J, Ali Chaouche MEA, Camadro JM, Le Crom S, Lelandais G, Devaux F. A Network of Paralogous Stress Response Transcription Factors in the Human Pathogen Candida glabrata. Front Microbiol 2016; 7:645. [PMID: 27242683 PMCID: PMC4860858 DOI: 10.3389/fmicb.2016.00645] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Accepted: 04/18/2016] [Indexed: 01/15/2023] Open
Abstract
The yeast Candida glabrata has become the second cause of systemic candidemia in humans. However, relatively few genome-wide studies have been conducted in this organism and our knowledge of its transcriptional regulatory network is quite limited. In the present work, we combined genome-wide chromatin immunoprecipitation (ChIP-seq), transcriptome analyses, and DNA binding motif predictions to describe the regulatory interactions of the seven Yap (Yeast AP1) transcription factors of C. glabrata. We described a transcriptional network containing 255 regulatory interactions and 309 potential target genes. We predicted with high confidence the preferred DNA binding sites for 5 of the 7 CgYaps and showed a strong conservation of the Yap DNA binding properties between S. cerevisiae and C. glabrata. We provided reliable functional annotation for 3 of the 7 Yaps and identified for Yap1 and Yap5 a core regulon which is conserved in S. cerevisiae, C. glabrata, and C. albicans. We uncovered new roles for CgYap7 in the regulation of iron-sulfur cluster biogenesis, for CgYap1 in the regulation of heme biosynthesis and for CgYap5 in the repression of GRX4 in response to iron starvation. These transcription factors define an interconnected transcriptional network at the cross-roads between redox homeostasis, oxygen consumption, and iron metabolism.
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Affiliation(s)
- Jawad Merhej
- Laboratoire de Biologie Computationnelle et Quantitative, Centre National de la Recherche Scientifique, Institut de Biologie Paris-Seine, UMR 7238, Sorbonne Universités, Université Pierre et Marie Curie Paris, France
| | - Antonin Thiebaut
- Laboratoire de Biologie Computationnelle et Quantitative, Centre National de la Recherche Scientifique, Institut de Biologie Paris-Seine, UMR 7238, Sorbonne Universités, Université Pierre et Marie Curie Paris, France
| | - Corinne Blugeon
- École Normale Supérieure, Paris Sciences et Lettres Research University, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Institut de Biologie de l'École Normale Supérieure, Plateforme Génomique Paris, France
| | - Juliette Pouch
- École Normale Supérieure, Paris Sciences et Lettres Research University, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Institut de Biologie de l'École Normale Supérieure, Plateforme Génomique Paris, France
| | - Mohammed El Amine Ali Chaouche
- École Normale Supérieure, Paris Sciences et Lettres Research University, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Institut de Biologie de l'École Normale Supérieure, Plateforme Génomique Paris, France
| | - Jean-Michel Camadro
- Centre National de la Recherche Scientifique, UMR 7592, Institut Jacques Monod, Université Paris Diderot, Sorbonne Paris Cité Paris, France
| | - Stéphane Le Crom
- Évolution, Centre National de la Recherche Scientifique, Institut de Biologie Paris-Seine, UMR 7138, Sorbonne Universités, Université Pierre et Marie Curie Paris, France
| | - Gaëlle Lelandais
- Centre National de la Recherche Scientifique, UMR 7592, Institut Jacques Monod, Université Paris Diderot, Sorbonne Paris Cité Paris, France
| | - Frédéric Devaux
- Laboratoire de Biologie Computationnelle et Quantitative, Centre National de la Recherche Scientifique, Institut de Biologie Paris-Seine, UMR 7238, Sorbonne Universités, Université Pierre et Marie Curie Paris, France
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25
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Kröber A, Scherlach K, Hortschansky P, Shelest E, Staib P, Kniemeyer O, Brakhage AA. HapX Mediates Iron Homeostasis in the Pathogenic Dermatophyte Arthroderma benhamiae but Is Dispensable for Virulence. PLoS One 2016; 11:e0150701. [PMID: 26960149 PMCID: PMC4784894 DOI: 10.1371/journal.pone.0150701] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 02/18/2016] [Indexed: 12/14/2022] Open
Abstract
For many pathogenic fungi, siderophore-mediated iron acquisition is essential for virulence. The process of siderophore production and further mechanisms to adapt to iron limitation are strictly controlled in fungi to maintain iron homeostasis. Here we demonstrate that the human pathogenic dermatophyte Arthroderma benhamiae produces the hydroxamate siderophores ferricrocin and ferrichrome C. Additionally, we show that the iron regulator HapX is crucial for the adaptation to iron starvation and iron excess, but is dispensable for virulence of A. benhamiae. Deletion of hapX caused downregulation of siderophore biosynthesis genes leading to a decreased production of siderophores during iron starvation. Furthermore, HapX was required for transcriptional repression of genes involved in iron-dependent pathways during iron-depleted conditions. Additionally, the ΔhapX mutant of A. benhamiae was sensitive to high-iron concentrations indicating that HapX also contributes to iron detoxification. In contrast to other pathogenic fungi, HapX of A. benhamiae was redundant for virulence and a ΔhapX mutant was still able to infect keratinized host tissues in vitro. Our findings underline the highly conserved role of the transcription factor HapX for maintaining iron homeostasis in ascomycetous fungi but, unlike in many other human and plant pathogenic fungi, HapX of A. benhamiae is not a virulence determinant.
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Affiliation(s)
- Antje Kröber
- Junior Research Group Fundamental Molecular Biology of Pathogenic Fungi, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Jena, Germany
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany
| | - Kirstin Scherlach
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany
| | - Peter Hortschansky
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany
| | - Ekaterina Shelest
- Systems Biology and Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany
| | - Peter Staib
- Junior Research Group Fundamental Molecular Biology of Pathogenic Fungi, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), Jena, Germany
| | - Olaf Kniemeyer
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany
- Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Axel A. Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany
- Institute of Microbiology, Friedrich Schiller University, Jena, Germany
- * E-mail:
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26
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The interaction of induction and repression mechanisms in the regulation of galacturonic acid-induced genes in Aspergillus niger. Fungal Genet Biol 2015; 82:32-42. [DOI: 10.1016/j.fgb.2015.06.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 06/04/2015] [Accepted: 06/08/2015] [Indexed: 02/05/2023]
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27
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Gressler M, Meyer F, Heine D, Hortschansky P, Hertweck C, Brock M. Phytotoxin production in Aspergillus terreus is regulated by independent environmental signals. eLife 2015; 4. [PMID: 26173180 PMCID: PMC4528345 DOI: 10.7554/elife.07861] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 07/13/2015] [Indexed: 01/09/2023] Open
Abstract
Secondary metabolites have a great potential as pharmaceuticals, but there are only a few examples where regulation of gene cluster expression has been correlated with ecological and physiological relevance for the producer. Here, signals, mediators, and biological effects of terrein production were studied in the fungus Aspergillus terreus to elucidate the contribution of terrein to ecological competition. Terrein causes fruit surface lesions and inhibits plant seed germination. Additionally, terrein is moderately antifungal and reduces ferric iron, thereby supporting growth of A. terreus under iron starvation. In accordance, the lack of nitrogen or iron or elevated methionine levels induced terrein production and was dependent on either the nitrogen response regulators AreA and AtfA or the iron response regulator HapX. Independent signal transduction allows complex sensing of the environment and, combined with its broad spectrum of biological activities, terrein provides a prominent example of adapted secondary metabolite production in response to environmental competition. DOI:http://dx.doi.org/10.7554/eLife.07861.001 Organisms produce a wide variety of small molecules called metabolites through the break down of food and other chemical reactions. Some of these molecules—known as primary metabolites—are required for growth, reproduction and other vital processes. Other molecules called secondary metabolites are not strictly required by the organism, but generally have other roles that may improve the individual’s ability to survive and reproduce. Fungi and other microbes produce a large variety of secondary metabolites, many of which are used as medicines to treat diseases in humans and other animals. For example, a molecule called lovastatin—which is produced by a fungus known as Aspergillus terreus—can reduce a human patient's risk of heart disease. However, it is not known what role many secondary metabolites play in the microbe that produced them. A. terreus lives in the soil, but it can also infect plants and animals. In addition to lovastatin, it also makes another secondary metabolite called terrein. A recent study identified the genes responsible for making terrein, and discovered that this molecule is harmful to plant cells and may help the fungus to colonize and thrive in the area immediately around plant roots, which is known as the rhizosphere. Here, Gressler et al. studied how terrein may help the fungus to cope with competitors in this environment. The experiments show that terrein increases the availability of iron and inhibits the growth of competing microbes. A shortage of iron or nitrogen-containing nutrients can stimulate the fungus to produce terrein, and elevated levels of a molecule called methionine have the same effect. These conditions are commonly found in the rhizosphere and further experiments identified several proteins in the fungus that are required for sensing them. Gressler et al.'s findings suggest that terrein helps to ensure that the fungus has sufficient nitrogen and iron to thrive in the rhizosphere. Also, this study confirms that the production of secondary metabolites in microbes can happen in response to elaborate cues from the environment, which may explain why only a limited number of secondary metabolites are produced by microbes when they are grown in the laboratory. Future studies will analyze other ways to activate the production of secondary metabolites outside of the microbe's normal environment, which may lead to the discovery of new important drugs. DOI:http://dx.doi.org/10.7554/eLife.07861.002
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Affiliation(s)
- Markus Gressler
- Microbial Biochemistry and Physiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Florian Meyer
- Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Daniel Heine
- Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Peter Hortschansky
- Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Christian Hertweck
- Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Matthias Brock
- Institute for Microbiology, Friedrich Schiller University, Jena, Germany.,Fungal Genetics and Biology Group, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
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28
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Giuliano Garisto Donzelli B, Gibson DM, Krasnoff SB. Intracellular siderophore but not extracellular siderophore is required for full virulence in Metarhizium robertsii. Fungal Genet Biol 2015; 82:56-68. [PMID: 26135511 DOI: 10.1016/j.fgb.2015.06.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 06/26/2015] [Accepted: 06/27/2015] [Indexed: 10/23/2022]
Abstract
Efficient iron acquisition mechanisms are fundamental for microbial survival in the environment and for pathogen virulence within their hosts. M. robertsii produces two known iron-binding natural products: metachelins, which are used to scavenge extracellular iron, and ferricrocin, which is strictly intracellular. To study the contribution of siderophore-mediated iron uptake and storage to M. robertsii fitness, we generated null mutants for each siderophore synthase gene (mrsidD and mrsidC, respectively), as well as for the iron uptake transcriptional repressor mrsreA. All of these mutants showed impaired germination speed, differential sensitivity to hydrogen peroxide, and differential ability to overcome iron chelation on growth-limiting iron concentrations. RT-qPCR data supported regulation of mrsreA, mrsidC, and mrsidD by supplied iron in vitro and during growth within the insect host, Spodoptera exigua. We also observed strong upregulation of the insect iron-binding proteins, transferrins, during infection. Insect bioassays revealed that ferricrocin is required for full virulence against S. exigua; neither the loss of metachelin production nor the deletion of the transcription factor mrsreA significantly affected M. robertsii virulence.
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Affiliation(s)
- Bruno Giuliano Garisto Donzelli
- School of Integrative Plant Science - Plant Pathology and Plant-Microbe Biology Section, Cornell University, Ithaca, NY 14853, United States.
| | - Donna M Gibson
- USDA ARS, Robert W. Holley Center for Agriculture and Health, 538 Tower Road, Ithaca, NY 14853, United States
| | - Stuart B Krasnoff
- USDA ARS, Robert W. Holley Center for Agriculture and Health, 538 Tower Road, Ithaca, NY 14853, United States
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29
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Merhej J, Delaveau T, Guitard J, Palancade B, Hennequin C, Garcia M, Lelandais G, Devaux F. Yap7 is a transcriptional repressor of nitric oxide oxidase in yeasts, which arose from neofunctionalization after whole genome duplication. Mol Microbiol 2015; 96:951-72. [DOI: 10.1111/mmi.12983] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/24/2015] [Indexed: 11/27/2022]
Affiliation(s)
- Jawad Merhej
- Sorbonne Universités, UPMC Univ. Paris 06, Institut de Biologie Paris Seine UMR 7238; Laboratoire de biologie computationnelle et quantitative; F-75006 Paris France
- CNRS, UMR 7238; Laboratoire de biologie computationnelle et quantitative; F-75006 Paris France
| | - Thierry Delaveau
- Sorbonne Universités, UPMC Univ. Paris 06, Institut de Biologie Paris Seine UMR 7238; Laboratoire de biologie computationnelle et quantitative; F-75006 Paris France
- CNRS, UMR 7238; Laboratoire de biologie computationnelle et quantitative; F-75006 Paris France
| | - Juliette Guitard
- Sorbonne Universités, UPMC Univ Paris 06, CR7; Centre d'Immunologie et des Maladies Infectieuses (CIMI-Paris); 91 Bd de l'hôpital F-75013 Paris France
- Inserm; U1135; CIMI-Paris; 91 Bd de l'hôpital F-75013 Paris France
- Assistance Publique-Hôpitaux de Paris, Hôpital St Antoine; Service de Parasitologie-Mycologie; F-75012 Paris France
- CNRS; ERL 8255; CIMI-Paris; 91 Bd de l'hôpital F-75013 Paris France
| | - Benoit Palancade
- Institut Jacques Monod, CNRS, UMR 7592, Univ Paris Diderot; Sorbonne Paris Cité; F-75205 Paris France
| | - Christophe Hennequin
- Sorbonne Universités, UPMC Univ Paris 06, CR7; Centre d'Immunologie et des Maladies Infectieuses (CIMI-Paris); 91 Bd de l'hôpital F-75013 Paris France
- Inserm; U1135; CIMI-Paris; 91 Bd de l'hôpital F-75013 Paris France
- Assistance Publique-Hôpitaux de Paris, Hôpital St Antoine; Service de Parasitologie-Mycologie; F-75012 Paris France
- CNRS; ERL 8255; CIMI-Paris; 91 Bd de l'hôpital F-75013 Paris France
| | - Mathilde Garcia
- Sorbonne Universités, UPMC Univ. Paris 06, Institut de Biologie Paris Seine UMR 7238; Laboratoire de biologie computationnelle et quantitative; F-75006 Paris France
- CNRS, UMR 7238; Laboratoire de biologie computationnelle et quantitative; F-75006 Paris France
| | - Gaëlle Lelandais
- Institut Jacques Monod, CNRS, UMR 7592, Univ Paris Diderot; Sorbonne Paris Cité; F-75205 Paris France
| | - Frédéric Devaux
- Sorbonne Universités, UPMC Univ. Paris 06, Institut de Biologie Paris Seine UMR 7238; Laboratoire de biologie computationnelle et quantitative; F-75006 Paris France
- CNRS, UMR 7238; Laboratoire de biologie computationnelle et quantitative; F-75006 Paris France
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