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Yu M, Song T, Yu J, Cao H, Pan X, Qi Z, Du Y, Liu W, Liu Y. UvVelC is important for conidiation and pathogenicity in the rice false smut pathogen Ustilaginoidea virens. Virulence 2024; 15:2301243. [PMID: 38240294 PMCID: PMC10802205 DOI: 10.1080/21505594.2023.2301243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Accepted: 12/28/2023] [Indexed: 01/23/2024] Open
Abstract
Rice false smut disease is one of the most significant rice diseases worldwide. Ustilaginoidea virens is the causative agent of this disease. Although several developmental and pathogenic genes have been identified and functionally analyzed, the pathogenic molecular mechanisms of U. virens remain elusive. The velvet family regulatory proteins are involved in fungal development, conidiation, and pathogenicity. In this study, we demonstrated the function of the VelC homolog UvVELC in U. virens. We identified the velvet family protein UvVELC and characterized its functions using a target gene deletion-strategy. Deletion of UvVELC resulted in conidiation failure and pathogenicity. The UvVELC expression levels during infection suggested that this gene might be involved in the early infection process. UvVELC is also important in resistance to abiotic stresses, the utilization efficiency of glucose, stachyose, raffinose, and other sugars, and the expression of transport-related genes. Moreover, UvVELC could physically interact with UvVEA in yeast, and UvVELC/UvVEA double-knockout mutants also failed in conidiation and pathogenicity. These results indicate that UvVELC play a critical role in the conidiation and pathogenicity in U. virens. Functional analysis indicated that UvVELC-mediated conidiation and nutrient acquisition from rice regulates the pathogenicity of U. virens. Understanding the function of the UvVELC homolog could provide a potential molecular target for controlling rice false smut disease.
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Affiliation(s)
- Mina Yu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Tianqiao Song
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Junjie Yu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Huijuan Cao
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Xiayan Pan
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Zhongqiang Qi
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Yan Du
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Wende Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Insistant of Plant Protection, Chinese Academy of Agricultural Science, Beijing, China
| | - Yongfeng Liu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
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Potenciano da Silva KL, Moraes D, Lechner B, Lindner H, Haas H, Almeida Soares CM, Silva-Bailão MG, Bailão AM. Fonsecaea pedrosoi produces ferricrocin and can utilize different host iron sources. Fungal Biol 2023; 127:1512-1523. [PMID: 38097325 DOI: 10.1016/j.funbio.2023.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 07/08/2023] [Accepted: 07/10/2023] [Indexed: 12/18/2023]
Abstract
The survival of living organisms depends on iron, one of the most abundant metals in the Earth's crust. Nevertheless, this micronutrient is poorly available in our aerobic atmosphere as well as inside the mammalian host. This problem is circumvented by the expression of high affinity iron uptake machineries, including the production of siderophores, in pathogenic fungi. Here we demonstrated that F. pedrosoi, the causative agent of the neglected tropical disease chromoblastomycosis, presents gene clusters for siderophore production. In addition, ten putative siderophore transporters were identified. Those genes are upregulated under iron starvation, a condition that induces the secretion of hydroxamates, as revealed by chrome azurol S assays. RP-HPLC and mass spectrometry analysis allowed the identification of ferricrocin as an intra- and extracellular siderophore. F. pedrosoi can grow in different iron sources, including the bacterial ferrioxamine B and the host proteins ferritin, hemoglobin and holotransferrin. Of note, addition of hemoglobin, lactoferrin and holotransferrin to the growth medium of macrophages infected with F. pedrosoi enhanced significantly fungal survival. The ability to produce siderophores in iron limited conditions added to the versatility to utilize different sources of iron are strategies that certainly may contribute to fungal survival inside the host.
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Affiliation(s)
| | - Dayane Moraes
- Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Goiás, Brazil.
| | - Beatrix Lechner
- Institute of Molecular Biology/ Biocenter, Medical University of Innsbruck, Innsbruck, Austria.
| | - Herbert Lindner
- Institute of Medical Biochemistry/Biocenter, Medical University of Innsbruck, Innsbruck, Austria.
| | - Hubertus Haas
- Institute of Molecular Biology/ Biocenter, Medical University of Innsbruck, Innsbruck, Austria.
| | | | | | - Alexandre Melo Bailão
- Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Goiás, Brazil.
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Pijuan J, Moreno DF, Yahya G, Moisa M, Ul Haq I, Krukiewicz K, Mosbah R, Metwally K, Cavalu S. Regulatory and pathogenic mechanisms in response to iron deficiency and excess in fungi. Microb Biotechnol 2023; 16:2053-2071. [PMID: 37804207 PMCID: PMC10616654 DOI: 10.1111/1751-7915.14346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 09/14/2023] [Accepted: 09/19/2023] [Indexed: 10/09/2023] Open
Abstract
Iron is an essential element for all eukaryote organisms because of its redox properties, which are important for many biological processes such as DNA synthesis, mitochondrial respiration, oxygen transport, lipid, and carbon metabolism. For this reason, living organisms have developed different strategies and mechanisms to optimally regulate iron acquisition, transport, storage, and uptake in different environmental responses. Moreover, iron plays an essential role during microbial infections. Saccharomyces cerevisiae has been of key importance for decrypting iron homeostasis and regulation mechanisms in eukaryotes. Specifically, the transcription factors Aft1/Aft2 and Yap5 regulate the expression of genes to control iron metabolism in response to its deficiency or excess, adapting to the cell's iron requirements and its availability in the environment. We also review which iron-related virulence factors have the most common fungal human pathogens (Aspergillus fumigatus, Cryptococcus neoformans, and Candida albicans). These factors are essential for adaptation in different host niches during pathogenesis, including different fungal-specific iron-uptake mechanisms. While being necessary for virulence, they provide hope for developing novel antifungal treatments, which are currently scarce and usually toxic for patients. In this review, we provide a compilation of the current knowledge about the metabolic response to iron deficiency and excess in fungi.
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Affiliation(s)
- Jordi Pijuan
- Laboratory of Neurogenetics and Molecular MedicineInstitut de Recerca Sant Joan de DéuBarcelonaSpain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIIIMadridSpain
| | - David F. Moreno
- Department of Molecular Cellular and Developmental BiologyYale UniversityNew HavenConnecticutUSA
- Systems Biology InstituteYale UniversityWest HavenConnecticutUSA
- Institut de Génétique et de Biologie Moléculaire et CellulaireIllkirchFrance
| | - Galal Yahya
- Department of Microbiology and Immunology, Faculty of PharmacyZagazig UniversityAl SharqiaEgypt
| | - Mihaela Moisa
- Faculty of Medicine and PharmacyUniversity of OradeaOradeaRomania
| | - Ihtisham Ul Haq
- Department of Physical Chemistry and Polymers TechnologySilesian University of TechnologyGliwicePoland
- Programa de Pós‐graduação em Inovação TecnológicaUniversidade Federal de Minas GeraisBelo HorizonteBrazil
| | - Katarzyna Krukiewicz
- Department of Physical Chemistry and Polymers TechnologySilesian University of TechnologyGliwicePoland
- Centre for Organic and Nanohybrid ElectronicsSilesian University of TechnologyGliwicePoland
| | - Rasha Mosbah
- Infection Control UnitHospitals of Zagazig UniversityZagazigEgypt
| | - Kamel Metwally
- Department of Medicinal Chemistry, Faculty of PharmacyUniversity of TabukTabukSaudi Arabia
- Department of Pharmaceutical Medicinal Chemistry, Faculty of PharmacyZagazig UniversityZagazigEgypt
| | - Simona Cavalu
- Faculty of Medicine and PharmacyUniversity of OradeaOradeaRomania
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4
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Sun K, Li Y, Gai Y, Wang J, Jian Y, Liu X, Wu L, Shim WB, Lee YW, Ma Z, Haas H, Yin Y. HapX-mediated H2B deub1 and SreA-mediated H2A.Z deposition coordinate in fungal iron resistance. Nucleic Acids Res 2023; 51:10238-10260. [PMID: 37650633 PMCID: PMC10602907 DOI: 10.1093/nar/gkad708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 07/26/2023] [Accepted: 08/15/2023] [Indexed: 09/01/2023] Open
Abstract
Plant pathogens are challenged by host-derived iron starvation or excess during infection, but the mechanism through which pathogens counteract iron stress is unclear. Here, we found that Fusarium graminearum encounters iron excess during the colonization of wheat heads. Deletion of heme activator protein X (FgHapX), siderophore transcription factor A (FgSreA) or both attenuated virulence. Further, we found that FgHapX activates iron storage under iron excess by promoting histone H2B deubiquitination (H2B deub1) at the promoter of the responsible gene. Meanwhile, FgSreA is shown to inhibit genes mediating iron acquisition during iron excess by facilitating the deposition of histone variant H2A.Z and histone 3 lysine 27 trimethylation (H3K27 me3) at the first nucleosome after the transcription start site. In addition, the monothiol glutaredoxin FgGrx4 is responsible for iron sensing and control of the transcriptional activity of FgHapX and FgSreA via modulation of their enrichment at target genes and recruitment of epigenetic regulators, respectively. Taken together, our findings elucidated the molecular mechanisms for adaptation to iron excess mediated by FgHapX and FgSreA during infection in F. graminearum and provide novel insights into regulation of iron homeostasis at the chromatin level in eukaryotes.
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Affiliation(s)
- Kewei Sun
- State Key Laboratory of Rice Biology, the Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Yiqing Li
- State Key Laboratory of Rice Biology, the Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Yunpeng Gai
- School of Grassland Science, Beijing Forestry University, Beijing, China
| | - Jingrui Wang
- State Key Laboratory of Rice Biology, the Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Yunqing Jian
- State Key Laboratory of Rice Biology, the Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Xin Liu
- Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Liang Wu
- Institute of Crop Science, Zhejiang University, Hangzhou, China
| | - Won-Bo Shim
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, USA
| | - Yin-Won Lee
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea
| | - Zhonghua Ma
- State Key Laboratory of Rice Biology, the Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Hubertus Haas
- Instiute of Molecular Biology, Biocenter, Medical University Innsbruck, Innsbruck A-6020, Austria
| | - Yanni Yin
- State Key Laboratory of Rice Biology, the Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou, China
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Happacher I, Aguiar M, Yap A, Decristoforo C, Haas H. Fungal siderophore metabolism with a focus on Aspergillus fumigatus: impact on biotic interactions and potential translational applications. Essays Biochem 2023; 67:829-842. [PMID: 37313590 PMCID: PMC10500206 DOI: 10.1042/ebc20220252] [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: 04/03/2023] [Revised: 05/22/2023] [Accepted: 05/26/2023] [Indexed: 06/15/2023]
Abstract
Iron is an essential trace element that is limiting in most habitats including hosts for fungal pathogens. Siderophores are iron-chelators synthesized by most fungal species for high-affinity uptake and intracellular handling of iron. Moreover, virtually all fungal species including those lacking siderophore biosynthesis appear to be able to utilize siderophores produced by other species. Siderophore biosynthesis has been shown to be crucial for virulence of several fungal pathogens infecting animals and plants revealing induction of this iron acquisition system during virulence, which offers translational potential of this fungal-specific system. The present article summarizes the current knowledge on the fungal siderophore system with a focus on Aspergillus fumigatus and its potential translational application including noninvasive diagnosis of fungal infections via urine samples, imaging of fungal infections via labeling of siderophores with radionuclides such as Gallium-68 for detection with positron emission tomography, conjugation of siderophores with fluorescent probes, and development of novel antifungal strategies.
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Affiliation(s)
- Isidor Happacher
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Mario Aguiar
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Annie Yap
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Clemens Decristoforo
- Department of Nuclear Medicine, Medical University Innsbruck, Innsbruck, Austria
| | - Hubertus Haas
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
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6
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Bailão AM, Silva KLPD, Moraes D, Lechner B, Lindner H, Haas H, Soares CMA, Silva-Bailão MG. Iron Starvation Induces Ferricrocin Production and the Reductive Iron Acquisition System in the Chromoblastomycosis Agent Cladophialophora carrionii. J Fungi (Basel) 2023; 9:727. [PMID: 37504717 PMCID: PMC10382037 DOI: 10.3390/jof9070727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 07/01/2023] [Accepted: 07/03/2023] [Indexed: 07/29/2023] Open
Abstract
Iron is a micronutrient required by almost all living organisms. Despite being essential, the availability of this metal is low in aerobic environments. Additionally, mammalian hosts evolved strategies to restrict iron from invading microorganisms. In this scenario, the survival of pathogenic fungi depends on high-affinity iron uptake mechanisms. Here, we show that the production of siderophores and the reductive iron acquisition system (RIA) are employed by Cladophialophora carrionii under iron restriction. This black fungus is one of the causative agents of chromoblastomycosis, a neglected subcutaneous tropical disease. Siderophore biosynthesis genes are arranged in clusters and, interestingly, two RIA systems are present in the genome. Orthologs of putative siderophore transporters were identified as well. Iron starvation regulates the expression of genes related to both siderophore production and RIA systems, as well as of two transcription factors that regulate iron homeostasis in fungi. A chrome azurol S assay demonstrated the secretion of hydroxamate-type siderophores, which were further identified via RP-HPLC and mass spectrometry as ferricrocin. An analysis of cell extracts also revealed ferricrocin as an intracellular siderophore. The presence of active high-affinity iron acquisition systems may surely contribute to fungal survival during infection.
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Affiliation(s)
- Alexandre Melo Bailão
- Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia 74690-900, Brazil
| | | | - Dayane Moraes
- Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia 74690-900, Brazil
| | - Beatrix Lechner
- Institute of Molecular Biology/Biocenter, Medical University of Innsbruck, 795J+RF Innsbruck, Austria
| | - Herbert Lindner
- Institute of Medical Biochemistry/Biocenter, Medical University of Innsbruck, 795J+RF Innsbruck, Austria
| | - Hubertus Haas
- Institute of Molecular Biology/Biocenter, Medical University of Innsbruck, 795J+RF Innsbruck, Austria
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7
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Wu JJ, Wu PC, Yago JI, Chung KR. The Regulatory Hub of Siderophore Biosynthesis in the Phytopathogenic Fungus Alternaria alternata. J Fungi (Basel) 2023; 9:jof9040427. [PMID: 37108881 PMCID: PMC10146468 DOI: 10.3390/jof9040427] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 03/22/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023] Open
Abstract
A GATA zinc finger-containing repressor (AaSreA) suppresses siderophore biosynthesis in the phytopathogenic fungus Alternaria alternata under iron-replete conditions. In this study, targeted gene deletion revealed two bZIP-containing transcription factors (AaHapX and AaAtf1) and three CCAAT-binding proteins (AaHapB, AaHapC, and AaHapE) that positively regulate gene expression in siderophore production. This is a novel phenotype regarding Atf1 and siderophore biosynthesis. Quantitative RT-PCR analyses revealed that only AaHapX and AaSreA were regulated by iron. AaSreA and AaHapX form a transcriptional feedback negative loop to regulate iron acquisition in response to the availability of environmental iron. Under iron-limited conditions, AaAtf1 enhanced the expression of AaNps6, thus playing a positive role in siderophore production. However, under nutrient-rich conditions, AaAtf1 plays a negative role in resistance to sugar-induced osmotic stress, and AaHapX plays a negative role in resistance to salt-induced osmotic stress. Virulence assays performed on detached citrus leaves revealed that AaHapX and AaAtf1 play no role in fungal pathogenicity. However, fungal strains carrying the AaHapB, AaHapC, or AaHapE deletion failed to incite necrotic lesions, likely due to severe growth deficiency. Our results revealed that siderophore biosynthesis and iron homeostasis are regulated by a well-organized network in A. alternata.
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8
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Li H, Dai J, Shi Y, Zhu X, Jia L, Yang Z. Molecular Regulatory Mechanism of the Iron-Ion-Promoted Asexual Sporulation of Antrodia cinnamomea in Submerged Fermentation Revealed by Comparative Transcriptomics. J Fungi (Basel) 2023; 9:jof9020235. [PMID: 36836349 PMCID: PMC9959139 DOI: 10.3390/jof9020235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/29/2023] [Accepted: 02/08/2023] [Indexed: 02/12/2023] Open
Abstract
Antrodia cinnamomea is a precious edible and medicinal fungus with activities of antitumor, antivirus, and immunoregulation. Fe2+ was found to promote the asexual sporulation of A. cinnamomea markedly, but the molecular regulatory mechanism of the effect is unclear. In the present study, comparative transcriptomics analysis using RNA sequencing (RNA-seq) and real time quantitative PCR (RT-qPCR) were conducted on A. cinnamomea mycelia cultured in the presence or absence of Fe2+ to reveal the molecular regulatory mechanisms underlying iron-ion-promoted asexual sporulation. The obtained mechanism is as follows: A. cinnamomea acquires iron ions through reductive iron assimilation (RIA) and siderophore-mediated iron assimilation (SIA). In RIA, ferrous iron ions are directly transported into cells by the high-affinity protein complex formed by a ferroxidase (FetC) and an Fe transporter permease (FtrA). In SIA, siderophores are secreted externally to chelate the iron in the extracellular environment. Then, the chelates are transported into cells through the siderophore channels (Sit1/MirB) on the cell membrane and hydrolyzed by a hydrolase (EstB) in the cell to release iron ions. The O-methyltransferase TpcA and the regulatory protein URBS1 promote the synthesis of siderophores. HapX and SreA respond to and maintain the balance of the intercellular concentration of iron ions. Furthermore, HapX and SreA promote the expression of flbD and abaA, respectively. In addition, iron ions promote the expression of relevant genes in the cell wall integrity signaling pathway, thereby accelerating the cell wall synthesis and maturation of spores. This study contributes to the rational adjustment and control of the sporulation of A. cinnamomea and thereby improves the efficiency of the preparation of inoculum for submerged fermentation.
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Affiliation(s)
- Huaxiang Li
- College of Food Science and Engineering, Yangzhou University, Yangzhou 225009, China
| | - Jianing Dai
- College of Food Science and Engineering, Yangzhou University, Yangzhou 225009, China
| | - Yu Shi
- College of Food Science and Engineering, Yangzhou University, Yangzhou 225009, China
| | - Xiaoyan Zhu
- Jiangsu Provincial Key Construction Laboratory of Probiotics Preparation, Huaiyin Institute of Technology, Huaian 223003, China
| | - Luqiang Jia
- College of Food Science and Engineering, Yangzhou University, Yangzhou 225009, China
| | - Zhenquan Yang
- College of Food Science and Engineering, Yangzhou University, Yangzhou 225009, China
- Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou University, Yangzhou 225009, China
- Correspondence:
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Luptáková D, Patil RH, Dobiáš R, Stevens DA, Pluháček T, Palyzová A, Káňová M, Navrátil M, Vrba Z, Hubáček P, Havlíček V. Siderophore-Based Noninvasive Differentiation of Aspergillus fumigatus Colonization and Invasion in Pulmonary Aspergillosis. Microbiol Spectr 2023; 11:e0406822. [PMID: 36719229 PMCID: PMC10100950 DOI: 10.1128/spectrum.04068-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 01/06/2023] [Indexed: 02/01/2023] Open
Abstract
Germination from conidia to hyphae and hyphal propagation of Aspergillus fumigatus are the key pathogenic steps in the development of invasive pulmonary aspergillosis (IPA). By applying in vitro observations in a clinical study of 13 patients diagnosed with probable IPA, here, we show that the transition from colonization to the A. fumigatus invasive stage is accompanied by the secretion of triacetylfusarinine C (TafC), triacetylfusarinine B (TafB), and ferricrocin (Fc) siderophores into urine, with strikingly better sensitivity performance than serum sampling. The best-performing index, the TafC/creatinine index, with a median value of 17.2, provided 92.3% detection sensitivity (95% confidence interval [CI], 64.0 to 99.8%) and 100% specificity (95% CI, 84.6 to 100%), i.e., substantially better than the corresponding indications provided by galactomannan (GM) and β-d-glucan (BDG) serology. For the same patient cohort, the serum GM and BDG sensitivities were 46.2 and 76.9%, respectively, and their specificities were 86.4 and 63.6%, respectively. The time-dependent specific appearance of siderophores in the host's urine represents an impactful clinical diagnostic advantage in the early discrimination of invasive aspergillosis from colonization. A favorable concentration of TafC in a clinical specimen distant from a deep infection site enables the noninvasive sampling of patients suffering from IPA. IMPORTANCE The importance of this research lies in the demonstration that siderophore analysis can distinguish between asymptomatic colonization and invasive pulmonary aspergillosis. We found clear associations between phases of fungal development, from conidial germination to the proliferative stage of invasive aspergillosis, and changes in secondary metabolite secretion. The critical extracellular fungal metabolites triacetylfusarinines C and B are produced during the polarized germination or postpolarized growth phase and reflect the morphological status of the proliferating pathogen. False positivity in Aspergillus diagnostics is minimized as mammalian cells do not synthesize Aspergillus siderophore or mycotoxin molecules.
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Affiliation(s)
- Dominika Luptáková
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - Rutuja H. Patil
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
- Department of Analytical Chemistry, Palacký University, Olomouc, Czechia
| | - Radim Dobiáš
- Department of Bacteriology and Mycology, Public Health Institute in Ostrava, Ostrava, Czechia
- Institute of Laboratory Medicine, Faculty of Medicine, University of Ostrava, Ostrava, Czechia
| | - David A. Stevens
- California Institute for Medical Research, San Jose, California, USA
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Tomáš Pluháček
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
- Department of Analytical Chemistry, Palacký University, Olomouc, Czechia
| | - Andrea Palyzová
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - Marcela Káňová
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Ostrava, Ostrava, Czechia
- Institute of Physiology and Pathophysiology, Faculty of Medicine, University of Ostrava, Ostrava, Czechia
- Department of Intensive Medicine, Emergency Medicine and Forensic Studies, University of Ostrava, Ostrava, Czechia
| | - Milan Navrátil
- Department of Hematooncology, University Hospital Ostrava, Ostrava, Czechia
| | - Zbyněk Vrba
- Lung Department, Krnov Combined Medical Facility, Krnov, Czechia
| | - Petr Hubáček
- Department of Medical Microbiology, Charles University, Prague, Czechia
- Motol University Hospital, Prague, Czechia
| | - Vladimír Havlíček
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
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10
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Ebrahim A, Alfwuaires MA, Abukhalil MH, Alasmari F, Ahmad F, Yao R, Luo Y, Huang Y. Schizosaccharomyces pombe Grx4, Fep1, and Php4: In silico analysis and expression response to different iron concentrations. Front Genet 2022; 13:1069068. [PMID: 36568394 PMCID: PMC9768344 DOI: 10.3389/fgene.2022.1069068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 11/16/2022] [Indexed: 12/12/2022] Open
Abstract
Due to iron's essential role in cellular metabolism, most organisms must maintain their homeostasis. In this regard, the fission yeast Schizosaccharomyces pombe (sp) uses two transcription factors to regulate intracellular iron levels: spFep1 under iron-rich conditions and spPhp4 under iron-deficient conditions, which are controlled by spGrx4. However, bioinformatics analysis to understand the role of the spGrx4/spFep1/spPhp4 axis in maintaining iron homeostasis in S. pombe is still lacking. Our study aimed to perform bioinformatics analysis on S. pombe proteins and their sequence homologs in Aspergillus flavus (af), Saccharomyces cerevisiae (sc), and Homo sapiens (hs) to understand the role of spGrx4, spFep1, and spPhp4 in maintaining iron homeostasis. The three genes' expression patterns were also examined at various iron concentrations. A multiple sequence alignment analysis of spGrx4 and its sequence homologs revealed a conserved cysteine residue in each PF00085 domain. Blast results showed that hsGLRX3 is most similar to spGrx4. In addition, spFep1 is most closely related in sequence to scDal80, whereas scHap4 is most similar to spFep1. We also found two highly conserved motifs in spFep1 and its sequence homologs that are significant for iron transport systems because they contain residues involved in iron homeostasis. The scHap4 is most similar to spPhp4. Using STRING to analyze protein-protein interactions, we found that spGrx4 interacts strongly with spPhp4 and spFep1. Furthermore, spGrx4, spPhp4, and spFep1 interact with spPhp2, spPhp3, and spPhp5, indicating that the three proteins play cooperative roles in iron homeostasis. At the highest level of Fe, spgrx4 had the highest expression, followed by spfep1, while spphp4 had the lowest expression; a contrast occurred at the lowest level of Fe, where spgrx4 expression remained constant. Our findings support the notion that organisms develop diverse strategies to maintain iron homeostasis.
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Affiliation(s)
- Alia Ebrahim
- Jiangsu Key Laboratory for Microbes and Genomics, School of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Manal A. Alfwuaires
- Department of Biological Sciences, Faculty of Science, King Faisal University, Al-Ahsa, Saudi Arabia
| | - Mohammad H. Abukhalil
- Department of Medical Analysis, Princess Aisha Bint Al-Hussein College of Nursing and Health Sciences, Al-Hussein Bin Talal University, Ma’an, Jordan,Department of Biology, College of Science, Al-Hussein Bin Talal University, Ma’an, Jordan
| | - Fawaz Alasmari
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Fawad Ahmad
- Jiangsu Key Laboratory for Microbes and Genomics, School of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Rui Yao
- Jiangsu Key Laboratory for Microbes and Genomics, School of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Ying Luo
- Jiangsu Key Laboratory for Microbes and Genomics, School of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Ying Huang
- Jiangsu Key Laboratory for Microbes and Genomics, School of Life Sciences, Nanjing Normal University, Nanjing, China,*Correspondence: Ying Huang,
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11
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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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12
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Moye-Rowley WS. Structure of the HapX:CCAAT-binding protein complex with DNA: A piece of the puzzle revealed. Structure 2022; 30:917-919. [PMID: 35803238 PMCID: PMC9830593 DOI: 10.1016/j.str.2022.05.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
DNA recognition by the HapX transcription factor from Aspergillus species requires the presence of a heterotrimeric DNA-binding protein called the CCAAT-binding complex (CBC). In this issue of Structure, Huber and colleagues illuminate the structural basis for the multivalent binding of the CBC, HapX, and the DNA target site.
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Affiliation(s)
- W. Scott Moye-Rowley
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA,Correspondence:
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13
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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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Role of the Heme Activator Protein Complex in the Sexual Development of Cryptococcus neoformans. mSphere 2022; 7:e0017022. [PMID: 35638350 PMCID: PMC9241503 DOI: 10.1128/msphere.00170-22] [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: 11/20/2022] Open
Abstract
The CCAAT-binding heme activator protein (HAP) complex, comprising the DNA-binding heterotrimeric complex Hap2/3/5 and transcriptional activation subunit HapX, is a key regulator of iron homeostasis, mitochondrial functions, and pathogenicity in Cryptococcus neoformans, which causes fatal meningoencephalitis. However, its role in the development of human fungal pathogens remains unclear. To elucidate the role of the HAP complex in C. neoformans development, we constructed hap2Δ, hap3Δ, hap5Δ, and hapXΔ mutants and their complemented congenic MATα H99 and MATa YL99a strains. The HAP complex plays a conserved role in iron utilization and stress responses in cells of both mating types. Deletion of any of the HAP complex components markedly enhances filamentation during bisexual mating. However, the Hap2/3/5 complex, but not HapX, is crucial in repressing pheromone production and cell fusion and is thus a critical repressor of sexual differentiation of C. neoformans. Interestingly, deletion of the heterotrimeric complex transcriptionally regulated both positive and negative regulators in the pheromone-responsive Cpk1 mitogen-activated protein kinase (MAPK) pathway. Chromatin immunoprecipitation-quantitative PCR analysis revealed that the HAP complex physically bound to the CCAAT motif of the CRG1 and GPA2 promoter regions. Notably, the HAP complex was differentially localized depending on the mating type in basal conditions; it was enriched in the nuclei of MATα cells but diffused in the cytoplasm of MATa cells. Interestingly, however, a portion of the HAP complex in both mating types relocalized to the cell membrane during mating. In conclusion, the Hap2/3/5 heterotrimeric complex and HapX play major and minor roles, respectively, in repressing the sexual development of C. neoformans in association with the Cpk1 MAPK pathway. IMPORTANCECryptococcus neoformans isolates are of two mating types: MATα strains, which are predominant, and MATa strains, isolated from the sub-Saharan African region, where cryptococcosis is most abundant and severe. Here, we demonstrated the function of the CCAAT-binding HAP complex (Hap2/3/5/X) as a transcriptional repressor of Cpk1 pathway-related genes in cells of both mating types. Deletion of any HAP complex component markedly enhanced filamentation without affecting normal sporulation. In particular, deletion of the DNA-binding HAP complex components (Hap2/3/5), but not HapX, markedly enhanced pheromone production and cell fusion efficiency, validating its repressive role in the early stage of mating in C. neoformans. The HAP complex regulates the expression of both negative and positive mating regulators and is thus crucial for the regulation of the Cpk1 MAPK pathway during mating. This study provides insights into the complex signaling networks governing the sexual differentiation of C. neoformans.
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15
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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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16
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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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17
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Seekles SJ, van Dam J, Arentshorst M, Ram AFJ. Natural Variation and the Role of Zn 2Cys 6 Transcription Factors SdrA, WarA and WarB in Sorbic Acid Resistance of Aspergillus niger. Microorganisms 2022; 10:microorganisms10020221. [PMID: 35208676 PMCID: PMC8877037 DOI: 10.3390/microorganisms10020221] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 01/16/2022] [Accepted: 01/18/2022] [Indexed: 02/07/2023] Open
Abstract
Weak acids, such as sorbic acid, are used as chemical food preservatives by the industry. Fungi overcome this weak-acid stress by inducing cellular responses mediated by transcription factors. In our research, a large-scale sorbic acid resistance screening was performed on 100 A. niger sensu stricto strains isolated from various sources to study strain variability in sorbic acid resistance. The minimal inhibitory concentration of undissociated (MICu) sorbic acid at pH = 4 in the MEB of the A. niger strains varies between 4.0 mM and 7.0 mM, with the average out of 100 strains being 4.8 ± 0.8 mM, when scored after 28 days. MICu values were roughly 1 mM lower when tested in commercial ice tea. Genome sequencing of the most sorbic-acid-sensitive strain among the isolates revealed a premature stop codon inside the sorbic acid response regulator encoding gene sdrA. Repairing this missense mutation increased the sorbic acid resistance, showing that the sorbic-acid-sensitive phenotype of this strain is caused by the loss of SdrA function. To identify additional transcription factors involved in weak-acid resistance, a transcription factor knock-out library consisting of 240 A. niger deletion strains was screened. The screen identified a novel transcription factor, WarB, which contributes to the resistance against a broad range of weak acids, including sorbic acid. The roles of SdrA, WarA and WarB in weak-acid resistance, including sorbic acid, were compared by creating single, double and the triple knock-out strains. All three transcription factors were found to have an additive effect on the sorbic acid stress response.
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Affiliation(s)
- Sjoerd J. Seekles
- TIFN, Agro Business Park 82, 6708 PW Wageningen, The Netherlands;
- Department Molecular Microbiology and Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands; (J.v.D.); (M.A.)
| | - Jisca van Dam
- Department Molecular Microbiology and Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands; (J.v.D.); (M.A.)
| | - Mark Arentshorst
- Department Molecular Microbiology and Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands; (J.v.D.); (M.A.)
| | - Arthur F. J. Ram
- TIFN, Agro Business Park 82, 6708 PW Wageningen, The Netherlands;
- Department Molecular Microbiology and Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands; (J.v.D.); (M.A.)
- Correspondence:
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18
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Yoshimura Y, Kobayashi Y, Kawaguchi T, Tani S. Improvement of cellulosic biomass-degrading enzyme production by reducing extracellular protease production in <i>Aspergillus aculeatus</i>. J GEN APPL MICROBIOL 2022; 68:143-150. [DOI: 10.2323/jgam.2021.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Yuko Yoshimura
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University
| | - Yuri Kobayashi
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University
| | - Takashi Kawaguchi
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University
| | - Shuji Tani
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University
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19
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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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20
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López-Berges MS, Scheven MT, Hortschansky P, Misslinger M, Baldin C, Gsaller F, Werner ER, Krüger T, Kniemeyer O, Weber J, Brakhage AA, Haas H. The bZIP Transcription Factor HapX Is Post-Translationally Regulated to Control Iron Homeostasis in Aspergillus fumigatus. Int J Mol Sci 2021; 22:ijms22147739. [PMID: 34299357 PMCID: PMC8307855 DOI: 10.3390/ijms22147739] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 07/15/2021] [Indexed: 11/21/2022] Open
Abstract
The airborne fungus Aspergillus fumigatus causes opportunistic infections in humans with high mortality rates in immunocompromised patients. Previous work established that the bZIP transcription factor HapX is essential for virulence via adaptation to iron limitation by repressing iron-consuming pathways and activating iron acquisition mechanisms. Moreover, HapX was shown to be essential for transcriptional activation of vacuolar iron storage and iron-dependent pathways in response to iron availability. Here, we demonstrate that HapX has a very short half-life during iron starvation, which is further decreased in response to iron, while siderophore biosynthetic enzymes are very stable. We identified Fbx22 and SumO as HapX interactors and, in agreement, HapX post-translational modifications including ubiquitination of lysine161, sumoylation of lysine242 and phosphorylation of threonine319. All three modifications were enriched in the immediate adaptation from iron-limiting to iron-replete conditions. Interfering with these post-translational modifications, either by point mutations or by inactivation, of Fbx22 or SumO, altered HapX degradation, heme biosynthesis and iron resistance to different extents. Consistent with the need to precisely regulate HapX protein levels, overexpression of hapX caused significant growth defects under iron sufficiency. Taken together, our results indicate that post-translational regulation of HapX is important to control iron homeostasis in A. fumigatus.
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Affiliation(s)
- Manuel Sánchez López-Berges
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (M.M.); (C.B.); (F.G.)
- Correspondence: (M.S.L.-B.); (A.A.B.); (H.H.)
| | - Mareike Thea Scheven
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (Leibniz-HKI), 07745 Jena, Germany; (M.T.S.); (P.H.); (T.K.); (O.K.); (J.W.)
- Institute of Microbiology, Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Peter Hortschansky
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (Leibniz-HKI), 07745 Jena, Germany; (M.T.S.); (P.H.); (T.K.); (O.K.); (J.W.)
| | - Matthias Misslinger
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (M.M.); (C.B.); (F.G.)
| | - Clara Baldin
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (M.M.); (C.B.); (F.G.)
| | - Fabio Gsaller
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (M.M.); (C.B.); (F.G.)
| | - Ernst R. Werner
- Division of Biological Chemistry, Biocenter, Innsbruck Medical University, 6020 Innsbruck, Austria;
| | - Thomas Krüger
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (Leibniz-HKI), 07745 Jena, Germany; (M.T.S.); (P.H.); (T.K.); (O.K.); (J.W.)
| | - Olaf Kniemeyer
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (Leibniz-HKI), 07745 Jena, Germany; (M.T.S.); (P.H.); (T.K.); (O.K.); (J.W.)
| | - Jakob Weber
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (Leibniz-HKI), 07745 Jena, Germany; (M.T.S.); (P.H.); (T.K.); (O.K.); (J.W.)
| | - Axel A. Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (Leibniz-HKI), 07745 Jena, Germany; (M.T.S.); (P.H.); (T.K.); (O.K.); (J.W.)
- Institute of Microbiology, Friedrich Schiller University Jena, 07743 Jena, Germany
- Correspondence: (M.S.L.-B.); (A.A.B.); (H.H.)
| | - Hubertus Haas
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (M.M.); (C.B.); (F.G.)
- Correspondence: (M.S.L.-B.); (A.A.B.); (H.H.)
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21
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Zuriegat Q, Zheng Y, Liu H, Wang Z, Yun Y. Current progress on pathogenicity-related transcription factors in Fusarium oxysporum. MOLECULAR PLANT PATHOLOGY 2021; 22:882-895. [PMID: 33969616 PMCID: PMC8232035 DOI: 10.1111/mpp.13068] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 03/25/2021] [Accepted: 03/25/2021] [Indexed: 05/03/2023]
Abstract
Fusarium oxysporum is a well-known soilborne plant pathogen that causes severe vascular wilt in economically important crops worldwide. During the infection process, F. oxysporum not only secretes various virulence factors, such as cell wall-degrading enzymes (CWDEs), effectors, and mycotoxins, that potentially play important roles in fungal pathogenicity but it must also respond to extrinsic abiotic stresses from the environment and the host. Over 700 transcription factors (TFs) have been predicted in the genome of F. oxysporum, but only 26 TFs have been functionally characterized in various formae speciales of F. oxysporum. Among these TFs, a total of 23 belonging to 10 families are required for pathogenesis through various mechanisms and pathways, and the zinc finger TF family is the largest family among these 10 families, which consists of 15 TFs that have been functionally characterized in F. oxysporum. In this review, we report current research progress on the 26 functionally analysed TFs in F. oxysporum and sort them into four groups based on their roles in F. oxysporum pathogenicity. Furthermore, we summarize and compare the biofunctions, involved pathways, putative targets, and homologs of these TFs and analyse the relationships among them. This review provides a systematic analysis of the regulation of virulence-related genes and facilitates further mechanistic analysis of TFs important in F. oxysporum virulence.
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Affiliation(s)
- Qussai Zuriegat
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsCollege of Life SciencesFujian Agriculture and Forestry UniversityFuzhouChina
| | - Yuru Zheng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsCollege of Life SciencesFujian Agriculture and Forestry UniversityFuzhouChina
- Fujian Institute for Food and Drug Quality ControlFuzhouChina
| | - Hong Liu
- College of Resources and EnvironmentFujian Agriculture and Forestry UniversityFuzhouChina
| | - Zonghua Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsCollege of Life SciencesFujian Agriculture and Forestry UniversityFuzhouChina
- Institute of OceanographyMinjiang UniversityFuzhouChina
| | - Yingzi Yun
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsCollege of Life SciencesFujian Agriculture and Forestry UniversityFuzhouChina
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22
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Nitrogen, Iron and Zinc Acquisition: Key Nutrients to Aspergillus fumigatus Virulence. J Fungi (Basel) 2021; 7:jof7070518. [PMID: 34203370 PMCID: PMC8303583 DOI: 10.3390/jof7070518] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 06/24/2021] [Accepted: 06/24/2021] [Indexed: 12/31/2022] Open
Abstract
Aspergillus fumigatus is a ubiquitous soil decomposer and an opportunistic pathogen that is characterized by its large metabolic machinery for acquiring nutrients from media. Lately, an ever-increasing number of genes involved in fungal nutrition has been associated with its virulence. Of these, nitrogen, iron, and zinc metabolism-related genes are particularly noteworthy, since 78% of them have a direct implication in virulence. In this review, we describe the sensing, uptake and regulation process of the acquisition of these nutrients, the connections between pathways and the virulence-implicated genes. Nevertheless, only 40% of the genes mentioned in this review have been assayed for roles in virulence, leaving a wide field of knowledge that remains uncertain and might offer new therapeutic and diagnostic targets.
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23
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Baldin C, Kühbacher A, Merschak P, Sastré-Velásquez LE, Abt B, Dietl AM, Haas H, Gsaller F. Inducible Selectable Marker Genes to Improve Aspergillus fumigatus Genetic Manipulation. J Fungi (Basel) 2021; 7:506. [PMID: 34202756 PMCID: PMC8305790 DOI: 10.3390/jof7070506] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/17/2021] [Accepted: 06/18/2021] [Indexed: 01/01/2023] Open
Abstract
The hygromycin B phosphotransferase gene from Escherichia coli and the pyrithiamine resistance gene from Aspergillus oryzae are two dominant selectable marker genes widely used to genetically manipulate several fungal species. Despite the recent development of CRISPR/Cas9 and marker-free systems, in vitro molecular tools to study Aspergillus fumigatus, which is a saprophytic fungus causing life-threatening diseases in immunocompromised hosts, still rely extensively on the use of dominant selectable markers. The limited number of drug selectable markers is already a critical aspect, but the possibility that their introduction into a microorganism could induce enhanced virulence or undesired effects on metabolic behavior constitutes another problem. In this context, here, we demonstrate that the use of ptrA in A. fumigatus leads to the secretion of a compound that allows the recovery of thiamine auxotrophy. In this study, we developed a simple modification of the two commonly used dominant markers in which the development of resistance can be controlled by the xylose-inducible promoter PxylP from Penicillium chrysogenum. This strategy provides an easy solution to avoid undesired side effects, since the marker expression can be readily silenced when not required.
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Affiliation(s)
| | | | | | | | | | | | - Hubertus Haas
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (C.B.); (A.K.); (P.M.); (L.E.S.-V.); (B.A.); (A.-M.D.)
| | - Fabio Gsaller
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (C.B.); (A.K.); (P.M.); (L.E.S.-V.); (B.A.); (A.-M.D.)
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24
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Fujii T, Inoue H, Matsushika A. The Transcription Factor Gene tclB2 Regulates Mannanolytic Enzyme Production in the Fungus Talaromyces cellulolyticus. Appl Biochem Biotechnol 2021; 193:3163-3172. [PMID: 34086255 DOI: 10.1007/s12010-021-03588-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 05/28/2021] [Indexed: 11/25/2022]
Abstract
The filamentous fungus Talaromyces cellulolyticus is a well-characterized cellulolytic and hemicellulolytic enzyme producer. In this study, the function of the tclB2 gene, which is a homolog of the manR/clrB/clr-2 gene in other filamentous fungi, in mannanolytic enzyme production by T. cellulolyticus was investigated. When a tclB2-disrupted strain (YDTclB) was grown in the presence of glucomannan, the production of β-mannanase, β-mannosidase, and α-galactosidase was decreased at the protein and transcriptional levels when compared to the control strain. In addition, a tclB2-overexpressing strain (YHTclB) showed higher β-mannanase and β-mannosidase production. When cellulose was used as a carbon source, the expression of genes encoding mannanolytic enzymes also decreased in YDTclB. These results suggested that TclB2 contributes to mannanolytic enzyme production in T. cellulolyticus. This work is the first study to identify a transcriptional regulator of mannanolytic enzyme genes in T. cellulolyticus.
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Affiliation(s)
- Tatsuya Fujii
- Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-0046, Japan.
| | - Hiroyuki Inoue
- Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-0046, Japan
| | - Akinori Matsushika
- Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-0046, Japan
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25
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Lima RM, Freitas E Silva KS, Silva LDC, Ribeiro JFR, Neves BJ, Brock M, Soares CMDA, da Silva RA, Pereira M. A structure-based approach for the discovery of inhibitors against methylcitrate synthase of Paracoccidioides lutzii. J Biomol Struct Dyn 2021; 40:9361-9373. [PMID: 34060981 DOI: 10.1080/07391102.2021.1930584] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Paracoccidioidomycosis (PCM) is a systemic mycosis, endemic in Latin America, caused by fungi of the genus Paracoccidioides. The treatment of PCM is complex, requiring a long treatment period, which often results in serious side effects. The aim of this study was to screen for inhibitors of a specific target of the fungus that is absent in humans. Methylcitrate synthase (MCS) is a unique enzyme of microorganisms and is responsible for the synthesis of methylcitrate at the beginning of the propionate degradation pathway. This pathway is essential for several microorganisms, since the accumulation of propionyl-CoA can impair virulence and prevent the development of the pathogen. We performed the modeling and molecular dynamics of the structure of Paracoccidioides lutzii MCS (PlMCS) and performed a virtual screening on 89,415 compounds against the active site of the enzyme. The compounds were selected according to the affinity and efficiency criteria of in vitro tests. Six compounds were able to inhibit the enzymatic activity of recombinant PlMCS but only the compound ZINC08964784 showed fungistatic and fungicidal activity against Paracoccidioides spp. cells. The analysis of the interaction profile of this compound with PlMCS showed its effectiveness in terms of specificity and stability when compared to the substrate (propionyl-CoA) of the enzyme. In addition, this compound did not show cytotoxicity in mammalian cells, with an excellent selectivity index. Our results suggest that the compound ZINC08964784 may become a promising alternative antifungal against Paracoccidioides spp. Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Raisa Melo Lima
- Molecular Biology Laboratory, Institute of Biological Sciences, Federal University of Goiás, Brazil.,Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, Brazil
| | | | - Lívia do Carmo Silva
- Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, Brazil
| | | | - Bruno Junior Neves
- Faculty of Pharmacy, Laboratory for Molecular Modeling and Drug Design, Federal University of Goiás, Goiânia, Brazil
| | - Matthias Brock
- School of Life Science, Fungal Biology Group, University of Nottingham, Nottingham, UK
| | | | - Roosevelt Alves da Silva
- Collaborative Nucleus of Biosystems, Institute of Exact Sciences, Federal University of Jataí, Jataí, Brazil
| | - Maristela Pereira
- Molecular Biology Laboratory, Institute of Biological Sciences, Federal University of Goiás, Brazil.,Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, Brazil
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26
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Interplay between transcriptional regulators and the SAGA chromatin modifying complex fine-tune iron homeostasis. J Biol Chem 2021; 297:100727. [PMID: 33933457 PMCID: PMC8217685 DOI: 10.1016/j.jbc.2021.100727] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/26/2021] [Accepted: 04/28/2021] [Indexed: 11/20/2022] Open
Abstract
The human fungal pathogen Candida albicans responds to iron deprivation by a global transcriptome reconfiguration known to be controlled by the transcriptional regulators Hap43 (also known as Cap2), Sef1, and the trimeric Hap2-Hap3-Hap5 complex. However, the relative roles of these regulators are not known. To dissect this system, we focused on the FRP1 and ACO1 genes, which are induced and repressed, respectively, under iron deprivation conditions. Chromatin immunoprecipitation assays showed that the trimeric HAP complex and Sef1 are recruited to both FRP1 and ACO1 promoters. While the HAP complex occupancy at the FRP1 promoter was Sef1-dependent, occupancy of Sef1 was not dependent on the HAP complex. Furthermore, iron deprivation elicited histone H3-Lys9 hyperacetylation and Pol II recruitment mediated by the trimeric HAP complex and Sef1 at the FRP1 promoter. In contrast, at the ACO1 promoter, the HAP trimeric complex and Hap43 promoted histone deacetylation and also limited Pol II recruitment under iron deprivation conditions. Mutational analysis showed that the SAGA subunits Gcn5, Spt7, and Spt20 are required for C. albicans growth in iron-deficient medium and for H3-K9 acetylation and transcription from the FRP1 promoter. Thus, the trimeric HAP complex promotes FRP1 transcription by stimulating H3K9Ac and Pol II recruitment and, along with Hap43, functions as a repressor of ACO1 by maintaining a deacetylated promoter under iron-deficient conditions. Thus, a regulatory network involving iron-responsive transcriptional regulators and the SAGA histone modifying complex functions as a molecular switch to fine-tune tight control of iron homeostasis gene expression in C. albicans.
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27
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Jung WH, Sánchez-León E, Kronstad JW. Coordinated regulation of iron metabolism in Cryptococcus neoformans by GATA and CCAAT transcription factors: connections with virulence. Curr Genet 2021; 67:583-593. [PMID: 33760942 DOI: 10.1007/s00294-021-01172-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 03/01/2021] [Accepted: 03/03/2021] [Indexed: 10/21/2022]
Abstract
Iron acquisition is critical for pathogenic fungi to adapt to and survive within the host environment. However, to same extent, the fungi must also avoid the detrimental effects caused by excess iron. The importance of iron has been demonstrated for the physiology and virulence of major fungal pathogens of humans including Aspergillus fumigatus, Candida albicans, and Cryptococcus neoformans. In particular, numerous studies have revealed that aspects of iron acquisition, metabolism, and homeostasis in the fungal pathogens are tightly controlled by conserved transcriptional regulators including a GATA-type iron transcription factor and the CCAAT-binding complex (CBC)/HapX orthologous protein complex. However, the specific downstream regulatory networks are slightly different in each fungus. In addition, roles have been proposed or demonstrated for other factors including monothiol glutaredoxins, BolA-like proteins, and Fe-S cluster incorporation on the GATA-type iron transcription factor and the CBC/HapX orthologous protein complex, although limited information is available. Here we focus on recent work on C. neoformans in the context of an emerging framework for fungal regulation of iron acquisition, metabolism, and homeostasis. Our specific goal is to summarize recent findings on transcriptional networks governed by the iron regulators Cir1 and HapX in C. neoformans.
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Affiliation(s)
- Won Hee Jung
- Department of Systems Biotechnology, Chung-Ang University, Anseong, 17546, Korea.
| | - Eddy Sánchez-León
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada
| | - James W Kronstad
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada.
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28
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Huang B, Lv Z, Li Y, Li C. Identification and functional characterization of natural resistance-associated macrophage protein 2 from sea cucumber Apostichopus japonicus. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 114:103835. [PMID: 32841622 DOI: 10.1016/j.dci.2020.103835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 08/15/2020] [Accepted: 08/15/2020] [Indexed: 06/11/2023]
Abstract
As a member of natural resistance-associated macrophage protein (Nramp) family, Nramp2 conservatively exists in the cell membrane across species and is essential for normal iron homeostasis in an H+-dependent manner. Withholding available iron represents an important host defense strategy. However, the function of Nramp2 in response to invading pathogens is largely unknown in invertebrates. In this study, a unique echinoderm Nramp2 was identified from sea cucumber Apostichopus japonicus (designated as AjNramp2). The cDNA sequence of AjNramp2 was 2360 bp, with a putative open reading frame of 1713 bp, encoding a typical Nramp domain containing protein with 570 amino acid residues. Structural analysis revealed that AjNramp2 consisted of highly conserved helix regions similar with the human Nramp2. Spatial expression analysis revealed that AjNramp2 was ubiquitously expressed in all examined tissues, with the highest level found in the intestine. Immunohistochemistry assay showed that AjNramp2 was mainly located in the cellular membrane in coelomocytes. Vibrio splendidus challenge and lipopolysaccharide (LPS) stimulation could significantly promote the expression of AjNramp2, which was consistent with the cellular iron level in coelomocytes. Moreover, when the expression of AjNramp2 was knocked down by siRNA-AjNramp2, the cellular iron level was coordinately decreased in coelomocytes under LPS stimulation. Taken together, results indicated that AjNramp2 serves as an iron transport receptor to withhold available iron and may contribute to the nutritional immunity defense system of sea cucumber.
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Affiliation(s)
- Bowen Huang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, PR China
| | - Zhimeng Lv
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, PR China
| | - Yanan Li
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, PR China
| | - Chenghua Li
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, PR China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, PR China.
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29
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The Protein Kinase A-Dependent Phosphoproteome of the Human Pathogen Aspergillus fumigatus Reveals Diverse Virulence-Associated Kinase Targets. mBio 2020; 11:mBio.02880-20. [PMID: 33323509 PMCID: PMC7773993 DOI: 10.1128/mbio.02880-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PKA is essential for the virulence of eukaryotic human pathogens. Understanding PKA signaling mechanisms is therefore fundamental to deciphering pathogenesis and developing novel therapies. Protein kinase A (PKA) signaling plays a critical role in the growth and development of all eukaryotic microbes. However, few direct targets have been characterized in any organism. The fungus Aspergillus fumigatus is a leading infectious cause of death in immunocompromised patients, but the specific molecular mechanisms responsible for its pathogenesis are poorly understood. We used this important pathogen as a platform for a comprehensive and multifaceted interrogation of both the PKA-dependent whole proteome and phosphoproteome in order to elucidate the mechanisms through which PKA signaling regulates invasive microbial disease. Employing advanced quantitative whole-proteomic and phosphoproteomic approaches with two complementary phosphopeptide enrichment strategies, coupled to an independent PKA interactome analysis, we defined distinct PKA-regulated pathways and identified novel direct PKA targets contributing to pathogenesis. We discovered three previously uncharacterized virulence-associated PKA effectors, including an autophagy-related protein, Atg24; a CCAAT-binding transcriptional regulator, HapB; and a CCR4-NOT complex-associated ubiquitin ligase, Not4. Targeted mutagenesis, combined with in vitro kinase assays, multiple murine infection models, structural modeling, and molecular dynamics simulations, was employed to characterize the roles of these new PKA targets in growth, environmental and antimicrobial stress responses, and pathogenesis in a mammalian system. We also elucidated the molecular mechanisms of PKA regulation for these effectors by defining the functionality of phosphorylation at specific PKA target sites. We have comprehensively characterized the PKA-dependent phosphoproteome and validated PKA targets as direct regulators of infectious disease for the first time in any pathogen, providing new insights into PKA signaling and control over microbial pathogenesis.
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30
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Zhu XF, Wu Q, Meng YT, Tao Y, Shen RF. AtHAP5A regulates iron translocation in iron-deficient Arabidopsis thaliana. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2020; 62:1910-1925. [PMID: 33405355 DOI: 10.1111/jipb.12984] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 06/16/2020] [Indexed: 06/12/2023]
Abstract
Iron (Fe) deficient plants employ multiple strategies to increase root uptake and root-to-shoot translocation of Fe. The identification of genes that are responsible for these processes, and a comprehensive understanding of the regulatory effects of transcriptional networks on their expression, including transcription factors (TFs), is underway in Arabidopsis thaliana. Here, we show that a Histone- or heme-associated proteins (HAP) transcription factor (TF), HAP5A, is necessary for the response to Fe deficiency in Arabidopsis. Its expression was induced under Fe deficiency, and the lack of HAP5A significantly decreased Fe translocation from the root to the shoot, resulting in substantial chlorosis of the newly expanded leaves, compared with the wild-type (WT, Col-0). Further analysis found that the expression of a gene encoding nicotianamine (NA) synthase (NAS1) was dramatically decreased in the hap5a mutant, regardless of the Fe status. Yeast-one-hybrid and ChIP analyses suggested that HAP5A directly binds to the promoter region of NAS1. Moreover, overexpression of NAS1 could rescue the chlorosis phenotype of hap5a in Fe deficient conditions. In summary, a novel pathway was elucidated, showing that NAS1-dependent translocation of Fe from the root to the shoot is controlled by HAP5A in Fe-deficient Arabidopsis thaliana.
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Affiliation(s)
- Xiao Fang Zhu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Qi Wu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yu Ting Meng
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ye Tao
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ren Fang Shen
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
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31
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Huang J, Lin M, Liang S, Qin Q, Liao S, Lu B, Wang Q. Transcription Analysis of Recombinant Trichoderma reesei HJ-48 to Compare the Molecular Basis for Fermentation of Glucose and Xylose. J Microbiol Biotechnol 2020; 30:1467-1479. [PMID: 32699200 PMCID: PMC9745658 DOI: 10.4014/jmb.2004.04007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 07/14/2020] [Accepted: 07/15/2020] [Indexed: 12/15/2022]
Abstract
Profiling the transcriptome changes involved in xylose metabolism by the fungus Trichoderma reesei allows for the identification of potential targets for ethanol production processing. In the present study, the transcriptome of T. reesei HJ-48 grown on xylose versus glucose was analyzed using nextgeneration sequencing technology. During xylose fermentation, numerous genes related to central metabolic pathways, including xylose reductase (XR) and xylitol dehydrogenase (XDH), were expressed at higher levels in T. reesei HJ-48. Notably, growth on xylose did not fully repress the genes encoding enzymes of the tricarboxylic acid and respiratory pathways. In addition, increased expression of several sugar transporters was observed during xylose fermentation. This study provides a valuable dataset for further investigation of xylose fermentation and provides a deeper insight into the various genes involved in this process.
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Affiliation(s)
- Jun Huang
- National Engineering Research Center for Non-Food Biorefinery, State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Key Laboratory of Biorefinery, Guangxi Biomass Engineering Technology Research Center, Guangxi Academy of Sciences, Nanning 530007, P.R. China,Corresponding author Phone: +86-0771-2503970 Fax: +86-0771-2503970 E-mail:
| | - Mei Lin
- National Engineering Research Center for Non-Food Biorefinery, State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Key Laboratory of Biorefinery, Guangxi Biomass Engineering Technology Research Center, Guangxi Academy of Sciences, Nanning 530007, P.R. China
| | - Shijie Liang
- National Engineering Research Center for Non-Food Biorefinery, State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Key Laboratory of Biorefinery, Guangxi Biomass Engineering Technology Research Center, Guangxi Academy of Sciences, Nanning 530007, P.R. China
| | - Qiurong Qin
- National Engineering Research Center for Non-Food Biorefinery, State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Key Laboratory of Biorefinery, Guangxi Biomass Engineering Technology Research Center, Guangxi Academy of Sciences, Nanning 530007, P.R. China
| | - Siming Liao
- National Engineering Research Center for Non-Food Biorefinery, State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Key Laboratory of Biorefinery, Guangxi Biomass Engineering Technology Research Center, Guangxi Academy of Sciences, Nanning 530007, P.R. China
| | - Bo Lu
- National Engineering Research Center for Non-Food Biorefinery, State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Key Laboratory of Biorefinery, Guangxi Biomass Engineering Technology Research Center, Guangxi Academy of Sciences, Nanning 530007, P.R. China
| | - Qingyan Wang
- National Engineering Research Center for Non-Food Biorefinery, State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Key Laboratory of Biorefinery, Guangxi Biomass Engineering Technology Research Center, Guangxi Academy of Sciences, Nanning 530007, P.R. China
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32
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HapX, an Indispensable bZIP Transcription Factor for Iron Acquisition, Regulates Infection Initiation by Orchestrating Conidial Oleic Acid Homeostasis and Cytomembrane Functionality in Mycopathogen Beauveria bassiana. mSystems 2020; 5:5/5/e00695-20. [PMID: 33051379 PMCID: PMC7567583 DOI: 10.1128/msystems.00695-20] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Conidial maturation and germination are highly coupled physiological processes in filamentous fungi that are critical for the pathogenicity of mycopathogens. Compared to the mechanisms involved in conidial germination, those of conidial reserves during maturation are less understood. The insect-pathogenic fungus Beauveria bassiana, as a representative species of filamentous fungi, is important for applied and fundamental research. In addition to its conserved roles in fungal adaptation to iron status, the bZIP transcription factor HapX acts as a master regulator involved in conidial virulence and regulates fatty acid/lipid metabolism. Further investigation revealed that the Δ9-fatty acid desaturase gene (Ole1) is a direct downstream target of HapX. This study reveals the HapX-Ole1 pathway involved in the fatty acid/lipid accumulation associated with conidial maturation and provides new insights into the startup mechanism of infection caused by spores from pathogenic fungi. In pathogenic filamentous fungi, conidial germination not only is fundamental for propagation in the environment but is also a critical step of infection. In the insect mycopathogen Beauveria bassiana, we genetically characterized the role of the basic leucine zipper (bZIP) transcription factor HapX (BbHapX) in conidial nutrient reserves and pathogen-host interaction. Ablation of BbHapX resulted in an almost complete loss of virulence in the topical inoculation and intrahemocoel injection assays. Comparative transcriptomic analysis revealed that BbHapX is required for fatty acid (FA)/lipid metabolism, and biochemical analyses indicated that BbHapX loss caused a significant reduction in conidial FA contents. Exogenous oleic acid could partially or completely restore the impaired phenotypes of the ΔBbHapX mutant, including germination rate, membrane integrity, vegetative growth, and virulence. BbHapX mediates fungal iron acquisition which is not required for desaturation of stearic acid. Additionally, inactivation of the Δ9-fatty acid desaturase gene (BbOle1) generated defects similar to those of the ΔBbHapX mutant; oleic acid also had significant restorative effects on the defective phenotypes of the ΔBbOle1 mutant. A gel retarding assay revealed that BbHapX directly regulated the expression of BbOle1. Lipidomic analyses indicated that both BbHapX and BbOle1 contributed to the homeostasis of phospholipids with nonpolar tails derived from oleic acid; therefore, exogenous phospholipids could significantly restore membrane integrity. These data reveal that the HapX-Ole1 pathway contributes to conidial fatty acid/lipid reserves and that there are important links between the lipid biology and membrane functionality involved in the early stages of infection caused by B.bassiana. IMPORTANCE Conidial maturation and germination are highly coupled physiological processes in filamentous fungi that are critical for the pathogenicity of mycopathogens. Compared to the mechanisms involved in conidial germination, those of conidial reserves during maturation are less understood. The insect-pathogenic fungus Beauveria bassiana, as a representative species of filamentous fungi, is important for applied and fundamental research. In addition to its conserved roles in fungal adaptation to iron status, the bZIP transcription factor HapX acts as a master regulator involved in conidial virulence and regulates fatty acid/lipid metabolism. Further investigation revealed that the Δ9-fatty acid desaturase gene (Ole1) is a direct downstream target of HapX. This study reveals the HapX-Ole1 pathway involved in the fatty acid/lipid accumulation associated with conidial maturation and provides new insights into the startup mechanism of infection caused by spores from pathogenic fungi.
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de Souza AF, de Paula MS, Lima RM, Silva MG, de Curcio JS, Pereira M, de Almeida Soares CM. The "Little Iron Waltz": The Ternary Response of Paracoccidioides spp. to Iron Deprivation. J Fungi (Basel) 2020; 6:E221. [PMID: 33053811 PMCID: PMC7712450 DOI: 10.3390/jof6040221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/06/2020] [Accepted: 10/09/2020] [Indexed: 12/15/2022] Open
Abstract
Paracoccidioides is a genus of thermodimorphic fungi that causes paracoccidioidomycosis. When in the host, the fungus undergoes several challenges, including iron deprivation imposed by nutritional immunity. In response to the iron deprivation triggered by the host, the fungus responds in a ternary manner using mechanisms of high affinity and specificity for the uptake of Fe, namely non-classical reductive iron uptake pathway, uptake of host iron proteins, and biosynthesis and uptake of siderophores. This triple response resembles the rhythmic structure of a waltz, which features three beats per compass. Using this connotation, we have constructed this review summarizing relevant findings in this area of study and pointing out new discoveries and perspectives that may contribute to the expansion of this "little iron waltz".
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Affiliation(s)
| | | | | | | | | | | | - Célia Maria de Almeida Soares
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, ICB II, Campus II, Universidade Federal de Goiás, Goiânia 74000-000, Brazil; (A.F.d.S.); (M.S.d.P.); (R.M.L.); (M.G.S.); (J.S.d.C.); (M.P.)
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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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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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A Transcriptional Regulatory Map of Iron Homeostasis Reveals a New Control Circuit for Capsule Formation in Cryptococcus neoformans. Genetics 2020; 215:1171-1189. [PMID: 32580959 DOI: 10.1534/genetics.120.303270] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Accepted: 06/18/2020] [Indexed: 11/18/2022] Open
Abstract
Iron is essential for the growth of the human fungal pathogen Cryptococcus neoformans within the vertebrate host, and iron sensing contributes to the elaboration of key virulence factors, including the formation of the polysaccharide capsule. C. neoformans employs sophisticated iron acquisition and utilization systems governed by the transcription factors Cir1 and HapX. However, the details of the transcriptional regulatory networks that are governed by these transcription factors and connections to virulence remain to be defined. Here, we used chromatin immunoprecipitation followed by next-generation sequencing (ChIP-seq) and transcriptome analysis (RNA-seq) to identify genes directly regulated by Cir1 and/or HapX in response to iron availability. Overall, 40 and 100 genes were directly regulated by Cir1, and 171 and 12 genes were directly regulated by HapX, under iron-limited and replete conditions, respectively. More specifically, we found that Cir1 directly controls the expression of genes required for iron acquisition and metabolism, and indirectly governs capsule formation by regulating specific protein kinases, a regulatory connection not previously revealed. HapX regulates the genes responsible for iron-dependent pathways, particularly under iron-depleted conditions. By analyzing target genes directly bound by Cir1 and HapX, we predicted the binding motifs for the transcription factors and verified that the purified proteins bind these motifs in vitro Furthermore, several direct target genes were coordinately and reciprocally regulated by Cir1 and HapX, suggesting that these transcription factors play conserved roles in the response to iron availability. In addition, biochemical analyses revealed that Cir1 and HapX are iron-containing proteins, implying that the regulatory networks of Cir1 and HapX may be influenced by the incorporation of iron into these proteins. Taken together, our identification of the genome-wide transcriptional networks provides a detailed understanding of the iron-related regulatory landscape, establishes a new connection between Cir1 and kinases that regulate capsule, and underpins genetic and biochemical analyses that reveal iron-sensing mechanisms for Cir1 and HapX in C. neoformans.
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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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Santos LPA, Assunção LDP, Lima PDS, Tristão GB, Brock M, Borges CL, Silva-Bailão MG, Soares CMDA, Bailão AM. Propionate metabolism in a human pathogenic fungus: proteomic and biochemical analyses. IMA Fungus 2020; 11:9. [PMID: 32617258 PMCID: PMC7324963 DOI: 10.1186/s43008-020-00029-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 03/11/2020] [Indexed: 01/06/2023] Open
Abstract
Fungi of the complex Paracoccidioides spp. are thermodimorphic organisms that cause Paracoccidioidomycosis, one of the most prevalent mycoses in Latin America. These fungi present metabolic mechanisms that contribute to the fungal survival in host tissues. Paracoccidioides lutzii activates glycolysis and fermentation while inactivates aerobic metabolism in iron deprivation, a condition found during infection. In lungs Paracoccidioides brasiliensis face a glucose poor environment and relies on the beta-oxidation to support energy requirement. During mycelium to yeast transition P. lutzii cells up-regulate transcripts related to lipid metabolism and cell wall remodeling in order to cope with the host body temperature. Paracoccidioides spp. cells also induce transcripts/enzymes of the methylcitrate cycle (MCC), a pathway responsible for propionyl-CoA metabolism. Propionyl-CoA is a toxic compound formed during the degradation of odd-chain fatty acids, branched chain amino acids and cholesterol. Therefore, fungi require a functional MCC for full virulence and the ability to metabolize propionyl-CoA is related to the virulence traits in Paracoccidioides spp. On this way we sought to characterize the propionate metabolism in Paracoccidioides spp. The data collected showed that P. lutzii grows in propionate and activates the MCC by accumulating transcripts and proteins of methylcitrate synthase (MCS), methylcitrate dehydratase (MCD) and methylisocitrate lyase (MCL). Biochemical characterization of MCS showed that the enzyme is regulated by phosphorylation, an event not yet described. Proteomic analyses further indicate that P. lutzii yeast cells degrades lipids and amino acids to support the carbon requirement for propionate metabolism. The induction of a putative propionate kinase suggests that fungal cells use propionyl-phosphate as an intermediate in the production of toxic propionyl-CoA. Concluding, the metabolism of propionate in P. lutzii is under regulation at transcriptional and phosphorylation levels and that survival on this carbon source requires additional mechanisms other than activation of MCC.
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Affiliation(s)
- Luiz Paulo Araújo Santos
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil
| | - Leandro do Prado Assunção
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil
| | - Patrícia de Souza Lima
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil
- Universidade Estadual de Goiás, Itapuranga, Brazil
| | - Gabriel Brum Tristão
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil
| | - Matthias Brock
- Fungal Biology and Genetics Group, University of Nottingham, Nottingham, UK
| | - Clayton Luiz Borges
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil
| | - Mirelle Garcia Silva-Bailão
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil
| | | | - Alexandre Melo Bailão
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil
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The siderophore repressor SreA maintains growth, hydrogen peroxide resistance, and cell wall integrity in the phytopathogenic fungus Alternaria alternata. Fungal Genet Biol 2020; 139:103384. [PMID: 32278718 DOI: 10.1016/j.fgb.2020.103384] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 03/25/2020] [Accepted: 03/31/2020] [Indexed: 01/18/2023]
Abstract
The siderophore-mediated iron uptake machinery is required by the tangerine pathotype of Alternaria alternata to colonize host plants. The present study reports the functions of the GATA-type transcription regulator SreA by analyzing loss- and gain-of-function mutants. The expression of sreA is transiently upregulated by excess iron. The sreA deficiency mutant (ΔsreA) shows severe growth defect but produces ACT toxin and incites necrotic lesions on citrus leaves as efficiently as wild type. SreA suppresses the expression of genes encoding polypeptides required for siderophore biosynthesis and transport under iron-replete conditions. Under iron-replete conditions, SreA impacts the expression of the genes encoding the NADPH oxidase complex involved in H2O2 production. SreA negatively impacts H2O2 resistance as ΔsreA increases resistance to H2O2. However, sreA deficiency has no effects on the expression of genes encoding several key factors (Yap1, Hog1, and Skn7) involved in oxidative stress resistance. ΔsreA increases resistance to calcofluor white and Congo red, which may suggest a role of SreA in the maintenance of cell wall integrity. Those are novel phenotypes associated with fungal sreA. Overall, our results indicate that SreA is required to protect fungal cells from cytotoxicity caused by excess iron. The results also highlight the regulatory functions of SreA and provide insights into the critical role of siderophore-mediated iron homeostasis in resistance to oxidative stress in A. alternata.
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Lyu HN, Liu HW, Keller NP, Yin WB. Harnessing diverse transcriptional regulators for natural product discovery in fungi. Nat Prod Rep 2020; 37:6-16. [DOI: 10.1039/c8np00027a] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This review covers diverse transcriptional regulators for the activation of secondary metabolism and novel natural product discovery in fungi.
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Affiliation(s)
- Hai-Ning Lyu
- State Key Laboratory of Mycology
- Institute of Microbiology
- Chinese Academy of Sciences
- Beijing
- China
| | - Hong-Wei Liu
- State Key Laboratory of Mycology
- Institute of Microbiology
- Chinese Academy of Sciences
- Beijing
- China
| | - Nancy P. Keller
- Department of Medical Microbiology and Immunology and Bacteriology
- University of Wisconsin–Madison
- Madison
- USA
| | - Wen-Bing Yin
- State Key Laboratory of Mycology
- Institute of Microbiology
- Chinese Academy of Sciences
- Beijing
- China
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The Putative Transcription Factor Gene thaB Regulates Cellulase and Xylanase Production at the Enzymatic and Transcriptional Level in the Fungus Talaromyces cellulolyticus. Appl Biochem Biotechnol 2019; 190:1360-1370. [PMID: 31773396 DOI: 10.1007/s12010-019-03190-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 11/11/2019] [Indexed: 12/17/2022]
Abstract
Talaromyces cellulolyticus is a promising strain for industrial cellulase production. In this study, the thaB gene, which is a homologue of the hap2/B gene in other filamentous fungi, was isolated and characterized. When grown in the presence of cellulose, culture supernatants of a thaB-disrupted strain (YDTha) exhibited decreased cellulase and xylanase enzymatic activities compared to the control strain. Furthermore, YDTha exhibited lower expression of the genes encoding cellulases and xylanases compared to the control strain. When cellobiose and lactose (soluble carbon sources) were used as carbon sources, the expression of the genes encoding cellulases and xylanases was decreased in both the YDTha and the control strains, though the expression levels in YDTha remained lower than those in the control strain. These results suggested that thaB has a positive role in cellulase and xylanase production in T. cellulolyticus.
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Wang Z, Ma T, Huang Y, Wang J, Chen Y, Kistler HC, Ma Z, Yin Y. A fungal ABC transporter FgAtm1 regulates iron homeostasis via the transcription factor cascade FgAreA-HapX. PLoS Pathog 2019; 15:e1007791. [PMID: 31545842 PMCID: PMC6788720 DOI: 10.1371/journal.ppat.1007791] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 10/11/2019] [Accepted: 08/05/2019] [Indexed: 02/07/2023] Open
Abstract
Iron homeostasis is important for growth, reproduction and other metabolic processes in all eukaryotes. However, the functions of ATP-binding cassette (ABC) transporters in iron homeostasis are largely unknown. Here, we found that one ABC transporter (named FgAtm1) is involved in regulating iron homeostasis, by screening sensitivity to iron stress for 60 ABC transporter mutants of Fusarium graminearum, a devastating fungal pathogen of small grain cereal crops worldwide. The lack of FgAtm1 reduces the activity of cytosolic Fe-S proteins nitrite reductase and xanthine dehydrogenase, which causes high expression of FgHapX via activating transcription factor FgAreA. FgHapX represses transcription of genes for iron-consuming proteins directly but activates genes for iron acquisition proteins by suppressing another iron regulator FgSreA. In addition, the transcriptional activity of FgHapX is regulated by the monothiol glutaredoxin FgGrx4. Furthermore, the phosphorylation of FgHapX, mediated by the Ser/Thr kinase FgYak1, is required for its functions in iron homeostasis. Taken together, this study uncovers a novel regulatory mechanism of iron homeostasis mediated by an ABC transporter in an important pathogenic fungus. Essential element iron plays important roles in many cellular processes in all organisms. The function of an ATP-binding cassette (ABC) transporter Atm1 in iron homeostasis has been characterized in Saccharomyces cerevisiae. Our study found that FgAtm1 regulates iron homeostasis via the transcription factor cascade FgAreA-HapX in F. graminearum and the function of FgHapX is dependent on its interaction with FgGrx4 and phosphorylation by the Ser/Thr kinase FgYak1. This study reveals a novel regulatory mechanism of iron homeostasis in an important plant pathogenic fungus, and advances our understanding in iron homeostasis and functions of ABC transporters in eukaryotes.
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Affiliation(s)
- Zhihui Wang
- State Key Laboratory of Rice Biology, Zhejiang University, Hangzhou, China
- Institute of Biotechnology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, China
| | - Tianling Ma
- State Key Laboratory of Rice Biology, Zhejiang University, Hangzhou, China
- Institute of Biotechnology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, China
| | - Yunyan Huang
- State Key Laboratory of Rice Biology, Zhejiang University, Hangzhou, China
- Institute of Biotechnology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, China
| | - Jing Wang
- State Key Laboratory of Rice Biology, Zhejiang University, Hangzhou, China
- Institute of Biotechnology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, China
| | - Yun Chen
- State Key Laboratory of Rice Biology, Zhejiang University, Hangzhou, China
- Institute of Biotechnology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, China
| | - H. Corby Kistler
- United States Department of Agriculture, Agricultural Research Service, St. Paul, Minnesota, United States of America
| | - Zhonghua Ma
- State Key Laboratory of Rice Biology, Zhejiang University, Hangzhou, China
- Institute of Biotechnology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, China
- * E-mail: (ZM); (YY)
| | - Yanni Yin
- State Key Laboratory of Rice Biology, Zhejiang University, Hangzhou, China
- Institute of Biotechnology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, China
- * E-mail: (ZM); (YY)
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Mao Y, Chen C. The Hap Complex in Yeasts: Structure, Assembly Mode, and Gene Regulation. Front Microbiol 2019; 10:1645. [PMID: 31379791 PMCID: PMC6652802 DOI: 10.3389/fmicb.2019.01645] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 07/03/2019] [Indexed: 01/19/2023] Open
Abstract
The CCAAT box-harboring proteins represent a family of heterotrimeric transcription factors which is highly conserved in eukaryotes. In fungi, one of the particularly important homologs of this family is the Hap complex that separates the DNA-binding domain from the activation domain and imposes essential impacts on regulation of a wide range of cellular functions. So far, a comprehensive summary of this complex has been described in filamentous fungi but not in the yeast. In this review, we summarize a number of studies related to the structure and assembly mode of the Hap complex in a list of representative yeasts. Furthermore, we emphasize recent advances in understanding the regulatory functions of this complex, with a special focus on its role in regulating respiration, production of reactive oxygen species (ROS) and iron homeostasis.
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Affiliation(s)
- Yinhe Mao
- Key Laboratory of Molecular Virology and Immunology, Unit of Pathogenic Fungal Infection and Host Immunity, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Changbin Chen
- Key Laboratory of Molecular Virology and Immunology, Unit of Pathogenic Fungal Infection and Host Immunity, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
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44
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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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45
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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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46
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Huang J, Ma Z, Zhong G, Sheppard DC, Lu L, Zhang S. The mitochondrial thiamine pyrophosphate transporter TptA promotes adaptation to low iron conditions and virulence in fungal pathogen Aspergillus fumigatus. Virulence 2019; 10:234-247. [PMID: 30880633 PMCID: PMC6527022 DOI: 10.1080/21505594.2019.1596505] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Aspergillus fumigatus is the most prevalent airborne fungal pathogen that causes invasive fungal infections in immunosuppressed individuals. Adaptation to iron limited conditions is crucial for A. fumigatus virulence. To identify novel genes that play roles in adaptation to low iron conditions we performed an insertional mutagenesis screen in A. fumigatus. Using this approach, we identified the tptA gene in A. fumigatus, which shares homology with the Saccharomyces cerevisiae thiamine pyrophosphate (ThPP) transporter encoding gene tpc1. Heterologous expression of tpc1 in the tptA deletion mutant completely restored the ThPP auxotrophy phenotype, suggesting that Tpc1 and TptA are functional orthologues. Importantly, TptA was required for adaptation to low iron conditions in A. fumigatus. The ΔtptA mutant had decreased resistance to the iron chelator bathophenanthroline disulfonate (BPS) with severe growth defects. Moreover, loss of tptA decreased the expression of hapX, which is a major transcription factor indispensable for adaptation to iron starvation in A. fumigatus. Overexpression of hapX in the ΔtptA strain greatly rescued the growth defect and siderophore production by A. fumigatus in iron-depleted conditions. Mutagenesis experiments demonstrated that the conserved residues related to ThPP uptake in TptA were also required for low iron adaptation. Furthermore, TptA-mediated adaptation to low iron conditions was found to be dependent on carbon sources. Finally, loss of tptA resulted in the attenuation of virulence in a murine model of aspergillosis. Taken together, this study demonstrated that the mitochondrial ThPP transporter TptA promotes low iron adaptation and virulence in A. fumigatus.
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Affiliation(s)
- Jingjing Huang
- a Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences , Nanjing Normal University , Nanjing , China
| | - Zhihua Ma
- a Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences , Nanjing Normal University , Nanjing , China
| | - Guowei Zhong
- b Department of Hygiene Analysis and Detection, School of Public Health , Nanjing Medical University , Nanjing , China
| | - Donald C Sheppard
- c Departments of Medicine, Microbiology & Immunology , McGill University , Montréal , QC , Canada.,d Infectious Diseases and Immunity in Global Health Program , Research Institute of the McGill University Health Centre , Montreal , QC , Canada
| | - Ling Lu
- a Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences , Nanjing Normal University , Nanjing , China
| | - Shizhu Zhang
- a Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences , Nanjing Normal University , Nanjing , China
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47
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Chelius CL, Ribeiro LFC, Huso W, Kumar J, Lincoln S, Tran B, Goo YA, Srivastava R, Harris SD, Marten MR. Phosphoproteomic and transcriptomic analyses reveal multiple functions for Aspergillus nidulans MpkA independent of cell wall stress. Fungal Genet Biol 2019; 125:1-12. [PMID: 30639305 DOI: 10.1016/j.fgb.2019.01.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 12/18/2018] [Accepted: 01/04/2019] [Indexed: 12/17/2022]
Abstract
The protein kinase MpkA plays a prominent role in the cell wall integrity signaling (CWIS) pathway, acting as the terminal MAPK activating expression of genes which encode cell wall biosynthetic enzymes and other repair functions. Numerous studies focus on MpkA function during cell wall perturbation. Here, we focus on the role MpkA plays outside of cell wall stress, during steady state growth. In an effort to seek other, as yet unknown, connections to this pathway, an mpkA deletion mutant (ΔmpkA) was subjected to phosphoproteomic and transcriptomic analysis. When compared to the control (isogenic parent of ΔmpkA), there is strong evidence suggesting MpkA is involved with maintaining cell wall strength, branching regulation, and the iron starvation pathway, among others. Particle-size analysis during shake flask growth revealed ΔmpkA mycelia were about 4 times smaller than the control strain and more than 90 cell wall related genes show significantly altered expression levels. The deletion mutant had a significantly higher branching rate than the control and phosphoproteomic results show putative branching-regulation proteins, such as CotA, LagA, and Cdc24, have a significantly different level of phosphorylation. When grown in iron limited conditions, ΔmpkA had no difference in growth rate or production of siderophores, whereas the control strain showed decreased growth rate and increased siderophore production. Transcriptomic data revealed over 25 iron related genes with altered transcript levels. Results suggest MpkA is involved with regulation of broad cellular functions in the absence of stress.
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Affiliation(s)
- Cynthia L Chelius
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, Baltimore, MD 21250, United States
| | - Liliane F C Ribeiro
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, Baltimore, MD 21250, United States
| | - Walker Huso
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, Baltimore, MD 21250, United States
| | - Jyothi Kumar
- Center for Plant Science Innovation and Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE 68588, United States
| | - Stephen Lincoln
- Department of Chemical and Biomolecular Engineering, University of Connecticut, Storrs, CT 06269, United States
| | - Bao Tran
- Mass Spectrometry Center, University of Maryland School of Pharmacy, Baltimore, MD, 21201, United States
| | - Young Ah Goo
- Mass Spectrometry Center, University of Maryland School of Pharmacy, Baltimore, MD, 21201, United States
| | - Ranjan Srivastava
- Department of Chemical and Biomolecular Engineering, University of Connecticut, Storrs, CT 06269, United States
| | - Steven D Harris
- Center for Plant Science Innovation and Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE 68588, United States
| | - Mark R Marten
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, Baltimore, MD 21250, United States.
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48
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Pracharova P, Lieben P, Pollet B, Beckerich JM, Bonnarme P, Landaud S, Swennen D. Geotrichum candidum gene expression and metabolite accumulation inside the cells reflect the strain oxidative stress sensitivity and ability to produce flavour compounds. FEMS Yeast Res 2019; 19:5116167. [PMID: 30295727 PMCID: PMC6211236 DOI: 10.1093/femsyr/foy111] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 10/04/2018] [Indexed: 12/02/2022] Open
Abstract
Geotrichum candidum is a fungus-like yeast widely used as a starter culture for cheese ripening for its proteolytic and lipolytic activities and its contribution to the cheese flavours. The sequenced strain G. candidum CLIB 918 was isolated from cheese Pont-L’Evêque. This strain's ability to produce volatile compounds was compared to the ability of a known strong sulphur compound producer G. candidum strain (Gc203). The aminotransferase-coding genes BAT2 and ARO8 were identified to be involved in methionine catabolism. The production of volatile compounds indicated that the sequenced strain was a moderate producer compared to the strong producer strain. The major volatile compounds were produced from sulphur amino acid, branched-chain amino acid and fatty acid metabolisms. Metabolite content of the cells showed that the ability of the strain to produce volatile compounds was inversely proportional to its ability to store amino acids inside the cells. Reduced glutathione, hypotaurine and taurine intracellular concentrations and volatile fatty aldehyde production indicated the role of oxidative stress sensitivity in flavour production. The increase in expression of several genes in a Reblochon-type cheese at the end of ripening confirmed that oxygen and iron were key factors regulating cheese flavour production.
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Affiliation(s)
- P Pracharova
- UMR GMPA, AgroParisTech, INRA, Université Paris-Saclay, 78850 Thiverval-Grignon, France
| | - P Lieben
- UMR GMPA, AgroParisTech, INRA, Université Paris-Saclay, 78850 Thiverval-Grignon, France
| | - B Pollet
- UMR GMPA, AgroParisTech, INRA, Université Paris-Saclay, 78850 Thiverval-Grignon, France
| | - J M Beckerich
- UMR GMPA, AgroParisTech, INRA, Université Paris-Saclay, 78850 Thiverval-Grignon, France
| | - P Bonnarme
- UMR GMPA, AgroParisTech, INRA, Université Paris-Saclay, 78850 Thiverval-Grignon, France
| | - S Landaud
- UMR GMPA, AgroParisTech, INRA, Université Paris-Saclay, 78850 Thiverval-Grignon, France
| | - D Swennen
- UMR GMPA, AgroParisTech, INRA, Université Paris-Saclay, 78850 Thiverval-Grignon, France
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49
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Misslinger M, Lechner BE, Bacher K, Haas H. Iron-sensing is governed by mitochondrial, not by cytosolic iron-sulfur cluster biogenesis in Aspergillus fumigatus. Metallomics 2018; 10:1687-1700. [PMID: 30395137 PMCID: PMC6250123 DOI: 10.1039/c8mt00263k] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 10/09/2018] [Indexed: 12/13/2022]
Abstract
Microorganisms have to adapt their metabolism to the requirements of their ecological niche to avoid iron shortage as well as iron toxicity. Therefore, mechanisms have been evolved to tightly regulate iron uptake, consumption, and detoxification, which depend on sensing the cellular iron status. In the facultative anaerobic yeast Saccharomyces cerevisiae, iron-sensing depends on mitochondrial (ISC) but not cytosolic iron-sulfur cluster assembly (CIA), while in mammals further processing of an ISC product via CIA is required for sensing of the cellular iron state. To address the question of how the obligatory aerobic mold Aspergillus fumigatus senses the cellular iron state, mutant strains allowing the downregulation of ISC and CIA were generated. These studies revealed that: (i) Nfs1 (Afu3g14240) and Nbp35 (Afu2g15960), which are involved in ISC and CIA, respectively, are essential for growth; (ii) a decrease in ISC (Nfs1 depletion) but not CIA (Nbp35 depletion) results in a transcriptional iron starvation response, (iii) a decrease in, ISC as well as CIA, increases the chelatable iron pool, accompanied by increased iron toxicity and increased susceptibility to oxidative stress and phleomycin. In agreement with ISC being essential for iron-sensing, a decrease in mitochondrial iron import by deletion of the mitochondrial iron importer MrsA resulted in an iron starvation response. Taken together, these data underline that iron-sensing in A. fumigatus depends on ISC but not CIA. Moreover, depletion of the glutathione pool via generating a mutant lacking γ-glutamylcysteine synthase, GshA (Afu3g13900), caused an iron starvation response, underlining a crucial role of glutathione in iron-sensing in A. fumigatus.
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Affiliation(s)
- Matthias Misslinger
- Division of Molecular Biology, Biocenter
, Medical University of Innsbruck
,
Innrain 80
, 6020 Innsbruck
, Austria
.
| | - Beatrix E. Lechner
- Division of Molecular Biology, Biocenter
, Medical University of Innsbruck
,
Innrain 80
, 6020 Innsbruck
, Austria
.
| | - Katharina Bacher
- Division of Molecular Biology, Biocenter
, Medical University of Innsbruck
,
Innrain 80
, 6020 Innsbruck
, Austria
.
| | - Hubertus Haas
- Division of Molecular Biology, Biocenter
, Medical University of Innsbruck
,
Innrain 80
, 6020 Innsbruck
, Austria
.
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50
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Wang Y, Deng C, Tian L, Xiong D, Tian C, Klosterman SJ. The Transcription Factor VdHapX Controls Iron Homeostasis and Is Crucial for Virulence in the Vascular Pathogen Verticillium dahliae. mSphere 2018; 3:e00400-18. [PMID: 30185514 PMCID: PMC6126142 DOI: 10.1128/msphere.00400-18] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Accepted: 08/14/2018] [Indexed: 11/20/2022] Open
Abstract
Iron homeostasis is essential for full virulence and viability in many pathogenic fungi. Here, we showed that the bZip transcription factor VdHapX functions as a key regulator of iron homeostasis for adaptation to iron-depleted and iron-excess conditions and is required for full virulence in the vascular wilt fungus, Verticillium dahliae Deletion of VdHapX impaired mycelial growth and conidiation under both iron starvation and iron sufficiency. Furthermore, disruption of VdHapX led to decreased formation of the long-lived survival structures of V. dahliae, known as microsclerotia. Expression of genes involved in iron utilization pathways and siderophore biosynthesis was misregulated in the ΔVdHapX strain under the iron-depleted condition. Additionally, the ΔVdHapX strain exhibited increased sensitivity to high iron concentrations and H2O2, indicating that VdHapX also contributes to iron or H2O2 detoxification. The ΔVdHapX strain showed a strong reduction in virulence on smoke tree seedlings (Cotinus coggygria) and was delayed in its ability to penetrate plant epidermal tissue.IMPORTANCE This study demonstrated that VdHapX is a conserved protein that mediates adaptation to iron starvation and excesses, affects microsclerotium formation, and is crucial for virulence of V. dahliae.
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Affiliation(s)
- Yonglin Wang
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing, China
| | - Chenglin Deng
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing, China
| | - Longyan Tian
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing, China
| | - Dianguang Xiong
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing, China
| | - Chengming Tian
- Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing, China
| | - Steven J Klosterman
- Agricultural Research Service, United States Department of Agriculture, Salinas, California, USA
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