1
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Barlit H, Romero AM, Gülhan A, Patnaik PK, Tyshkovskiy A, Martínez-Pastor MT, Gladyshev VN, Puig S, Labunskyy VM. Ribosome profiling reveals the role of yeast RNA-binding proteins Cth1 and Cth2 in translational regulation. iScience 2024; 27:109868. [PMID: 38779483 PMCID: PMC11109004 DOI: 10.1016/j.isci.2024.109868] [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: 09/28/2023] [Revised: 03/12/2024] [Accepted: 04/29/2024] [Indexed: 05/25/2024] Open
Abstract
Iron serves as a cofactor for enzymes involved in several steps of protein translation, but the control of translation during iron limitation is not understood at the molecular level. Here, we report a genome-wide analysis of protein translation in response to iron deficiency in yeast using ribosome profiling. We show that iron depletion affects global protein synthesis and leads to translational repression of multiple genes involved in iron-related processes. Furthermore, we demonstrate that the RNA-binding proteins Cth1 and Cth2 play a central role in this translational regulation by repressing the activity of the iron-dependent Rli1 ribosome recycling factor and inhibiting mitochondrial translation and heme biosynthesis. Additionally, we found that iron deficiency represses MRS3 mRNA translation through increased expression of antisense long non-coding RNA. Together, our results reveal complex gene expression and protein synthesis remodeling in response to low iron, demonstrating how this important metal affects protein translation at multiple levels.
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Affiliation(s)
- Hanna Barlit
- Department of Dermatology, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Antonia M. Romero
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Valencia, Spain
| | - Ali Gülhan
- Department of Dermatology, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Praveen K. Patnaik
- Department of Dermatology, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
| | - Alexander Tyshkovskiy
- Division of Genetics, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - María T. Martínez-Pastor
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Valencia, Spain
- Departamento de Bioquímica y Biología Molecular, Universitat de València, Valencia, Spain
| | - Vadim N. Gladyshev
- Division of Genetics, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Sergi Puig
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Valencia, Spain
| | - Vyacheslav M. Labunskyy
- Department of Dermatology, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA
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2
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Yona A, Fridman M. Poacic Acid, a Plant-Derived Stilbenoid, Augments Cell Wall Chitin Production, but Its Antifungal Activity Is Hindered by This Polysaccharide and by Fungal Essential Metals. Biochemistry 2024; 63:1051-1065. [PMID: 38533731 PMCID: PMC11025111 DOI: 10.1021/acs.biochem.3c00595] [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: 10/29/2023] [Revised: 03/17/2024] [Accepted: 03/18/2024] [Indexed: 03/28/2024]
Abstract
Climate and environmental changes have modified the habitats of fungal pathogens, inflicting devastating effects on livestock and crop production. Additionally, drug-resistant fungi are increasing worldwide, driving the urgent need to identify new molecular scaffolds for the development of antifungal agents for humans, animals, and plants. Poacic acid (PA), a plant-derived stilbenoid, was recently discovered to be a novel molecular scaffold that inhibits the growth of several fungi. Its antifungal activity has been associated with perturbation of the production/assembly of the fungal cell wall β-1,3-glucan, but its mode of action is not resolved. In this study, we investigated the antifungal activity of PA and its derivatives on a panel of yeast. PA had a fungistatic effect on S. cerevisiae and a fungicidal effect on plasma membrane-damaged Candida albicans mutants. Live cell fluorescence microscopy experiments revealed that PA increases chitin production and modifies its cell wall distribution. Chitin production and cell growth returned to normal after prolonged incubation. The antifungal activity of PA was reduced in the presence of exogenous chitin, suggesting that the potentiation of chitin production is a stress response that helps the yeast cell overcome the effect of this antifungal stilbenoid. Growth inhibition was also reduced by metal ions, indicating that PA affects the metal homeostasis. These findings suggest that PA has a complex antifungal mechanism of action that involves perturbation of the cell wall β-1,3-glucan production/assembly, chitin production, and metal homeostasis.
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Affiliation(s)
- Adi Yona
- School of Chemistry, Raymond
& Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Micha Fridman
- School of Chemistry, Raymond
& Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
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3
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Were E, Viljoen A, Rasche F. Iron necessity for chlamydospore germination in Fusarium oxysporum f. sp. cubense TR4. Biometals 2023; 36:1295-1306. [PMID: 37380939 PMCID: PMC10684721 DOI: 10.1007/s10534-023-00519-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 06/19/2023] [Indexed: 06/30/2023]
Abstract
Fusarium wilt disease of banana, caused by the notorious soil-borne pathogen Fusarium oxysporum f. sp. cubense Tropical Race 4 (Foc TR4), is extremely difficult to manage. Manipulation of soil pH or application of synthetic iron chelators can suppress the disease through iron starvation, which inhibits the germination of pathogen propagules called chlamydospores. However, the effect of iron starvation on chlamydospore germination is largely unknown. In this study, scanning electron microscopy was used to assemble the developmental sequence of chlamydospore germination and to assess the effect of iron starvation and pH in vitro. Germination occurs in three distinct phenotypic transitions (swelling, polarized growth, outgrowth). Outgrowth, characterized by formation of a single protrusion (germ tube), occurred at 2 to 3 h, and a maximum value of 69.3% to 76.7% outgrowth was observed at 8 to 10 h after germination induction. Germination exhibited plasticity with pH as over 60% of the chlamydospores formed a germ tube between pH 3 and pH 11. Iron-starved chlamydospores exhibited polarized-growth arrest, characterized by the inability to form a germ tube. Gene expression analysis of rnr1 and rnr2, which encode the iron-dependent enzyme ribonucleotide reductase, showed that rnr2 was upregulated (p < 0.0001) in iron-starved chlamydospores compared to the control. Collectively, these findings suggest that iron and extracellular pH are crucial for chlamydospore germination in Foc TR4. Moreover, inhibition of germination by iron starvation may be linked to a different mechanism, rather than repression of the function of ribonucleotide reductase, the enzyme that controls growth by regulation of DNA synthesis.
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Affiliation(s)
- Evans Were
- Institute of Agricultural Sciences in the Tropics (Hans-Ruthenberg-Institute), University of Hohenheim, 70599, Stuttgart, Germany
| | - Altus Viljoen
- Department of Plant Pathology, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa
| | - Frank Rasche
- Institute of Agricultural Sciences in the Tropics (Hans-Ruthenberg-Institute), University of Hohenheim, 70599, Stuttgart, Germany.
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4
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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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5
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Van Genechten W, Vergauwen R, Van Dijck P. The intricate link between iron, mitochondria and azoles in Candida species. FEBS J 2023. [PMID: 37846606 DOI: 10.1111/febs.16977] [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: 05/21/2023] [Revised: 09/19/2023] [Accepted: 10/13/2023] [Indexed: 10/18/2023]
Abstract
Invasive fungal infections are rapidly increasing, and the opportunistic pathogenic Candida species are the fourth most common cause of nosocomial systemic infections. The current antifungal classes, of which azoles are the most widely used, all have shortcomings. Azoles are generally considered fungistatic rather than fungicidal, they do not actively kill fungal cells and therefore resistance against azoles can be rapidly acquired. Combination therapies with azoles provide an interesting therapeutic outlook and agents limiting iron are excellent candidates. We summarize how iron is acquired by the host and transported towards both storage and iron-utilizing organelles. We indicate whether these pathways alter azole susceptibility and/or tolerance, to finally link these transport mechanisms to mitochondrial iron availability. In this review, we highlight putative novel intracellular iron shuffling mechanisms and indicate that mitochondrial iron dynamics in relation to azole treatment and iron limitation is a significant knowledge gap.
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Affiliation(s)
- Wouter Van Genechten
- Laboratory of Molecular Cell Biology, Department of Biology, Institute of Botany and Microbiology, KU Leuven, Belgium
| | - Rudy Vergauwen
- Laboratory of Molecular Cell Biology, Department of Biology, Institute of Botany and Microbiology, KU Leuven, Belgium
| | - Patrick Van Dijck
- Laboratory of Molecular Cell Biology, Department of Biology, Institute of Botany and Microbiology, KU Leuven, Belgium
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6
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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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7
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Aghabi D, Sloan M, Gill G, Hartmann E, Antipova O, Dou Z, Guerra AJ, Carruthers VB, Harding CR. The vacuolar iron transporter mediates iron detoxification in Toxoplasma gondii. Nat Commun 2023; 14:3659. [PMID: 37339985 PMCID: PMC10281983 DOI: 10.1038/s41467-023-39436-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 06/13/2023] [Indexed: 06/22/2023] Open
Abstract
Iron is essential to cells as a cofactor in enzymes of respiration and replication, however without correct storage, iron leads to the formation of dangerous oxygen radicals. In yeast and plants, iron is transported into a membrane-bound vacuole by the vacuolar iron transporter (VIT). This transporter is conserved in the apicomplexan family of obligate intracellular parasites, including in Toxoplasma gondii. Here, we assess the role of VIT and iron storage in T. gondii. By deleting VIT, we find a slight growth defect in vitro, and iron hypersensitivity, confirming its essential role in parasite iron detoxification, which can be rescued by scavenging of oxygen radicals. We show VIT expression is regulated by iron at transcript and protein levels, and by altering VIT localization. In the absence of VIT, T. gondii responds by altering expression of iron metabolism genes and by increasing antioxidant protein catalase activity. We also show that iron detoxification has an important role both in parasite survival within macrophages and in virulence in a mouse model. Together, by demonstrating a critical role for VIT during iron detoxification in T. gondii, we reveal the importance of iron storage in the parasite and provide the first insight into the machinery involved.
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Affiliation(s)
- Dana Aghabi
- Wellcome Centre of Integrative Parasitology, School of Infection and Immunity, University of Glasgow, Glasgow, UK
| | - Megan Sloan
- Wellcome Centre of Integrative Parasitology, School of Infection and Immunity, University of Glasgow, Glasgow, UK
| | - Grace Gill
- Wellcome Centre of Integrative Parasitology, School of Infection and Immunity, University of Glasgow, Glasgow, UK
| | - Elena Hartmann
- Wellcome Centre of Integrative Parasitology, School of Infection and Immunity, University of Glasgow, Glasgow, UK
| | - Olga Antipova
- X-Ray Sciences Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
| | - Zhicheng Dou
- Department of Biological Sciences, Clemson University, Clemson, SC, USA
| | - Alfredo J Guerra
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA
- Cayman Chemical Company, Ann Arbor, MI, USA
| | - Vern B Carruthers
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA
| | - Clare R Harding
- Wellcome Centre of Integrative Parasitology, School of Infection and Immunity, University of Glasgow, Glasgow, UK.
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8
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Cai H, Zhang H, Guo DH, Wang Y, Gu J. Genomic Data Mining Reveals Abundant Uncharacterized Transporters in Coccidioides immitis and Coccidioides posadasii. J Fungi (Basel) 2022; 8:jof8101064. [PMID: 36294626 PMCID: PMC9604845 DOI: 10.3390/jof8101064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 10/01/2022] [Accepted: 10/08/2022] [Indexed: 11/16/2022] Open
Abstract
Coccidioides immitis and Coccidioides posadasii are causative agents of coccidioidomycosis, commonly known as Valley Fever. The increasing Valley Fever cases in the past decades, the expansion of endemic regions, and the rising azole drug-resistant strains have underscored an urgent need for a better understanding of Coccidioides biology and new antifungal strategies. Transporters play essential roles in pathogen survival, growth, infection, and adaptation, and are considered as potential drug targets. However, the composition and roles of transport machinery in Coccidioides remain largely unknown. In this study, genomic data mining revealed an abundant, uncharacterized repertoire of transporters in Coccidioides genomes. The catalog included 1288 and 1235 transporter homologs in C. immitis and C. posadasii, respectively. They were further annotated to class, subclass, family, subfamily and range of substrates based on the Transport Classification (TC) system. They may play diverse roles in nutrient uptake, metabolite secretion, ion homeostasis, drug efflux, or signaling. This study represents an initial effort for a systems-level characterization of the transport machinery in these understudied fungal pathogens.
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Affiliation(s)
- Hong Cai
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX 78249, USA
- South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Hao Zhang
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX 78249, USA
- South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Daniel H. Guo
- Strake Jesuit College Preparatory, Houston, TX 77036, USA
| | - Yufeng Wang
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX 78249, USA
- South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, TX 78249, USA
- Correspondence: (Y.W.); (J.G.)
| | - Jianying Gu
- Department of Biology, College of Staten Island, City University of New York, Staten Island, New York, NY 10314, USA
- Correspondence: (Y.W.); (J.G.)
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9
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Were E, Schöne J, Viljoen A, Rasche F. De novo synthesis of ferrichrome by Fusarium oxysporum f. sp. cubense TR4 in response to iron starvation. Fungal Biol 2022; 126:521-527. [DOI: 10.1016/j.funbio.2022.05.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 05/03/2022] [Accepted: 05/24/2022] [Indexed: 11/04/2022]
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10
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Iron homeostasis in the absence of ferricrocin and its consequences in fungal development and insect virulence in Beauveria bassiana. Sci Rep 2021; 11:19624. [PMID: 34608174 PMCID: PMC8490459 DOI: 10.1038/s41598-021-99030-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 09/14/2021] [Indexed: 11/28/2022] Open
Abstract
The putative ferricrocin synthetase gene ferS in the fungal entomopathogen Beauveria bassiana BCC 2660 was identified and characterized. The 14,445-bp ferS encodes a multimodular nonribosomal siderophore synthetase tightly clustered with Fusarium graminearum ferricrocin synthetase. Functional analysis of this gene was performed by disruption with the bar cassette. ΔferS mutants were verified by Southern and PCR analyses. HPLC and TLC analyses of crude extracts indicated that biosynthesis of ferricrocin was abolished in ΔferS. Insect bioassays surprisingly indicated that ΔferS killed the Spodoptera exigua larvae faster (LT50 59 h) than wild type (66 h). Growth and developmental assays of the mutant and wild type demonstrated that ΔferS had a significant increase in germination under iron depletion and radial growth and a decrease in conidiation. Mitotracker staining showed that the mitochondrial activity was enriched in ΔferS under both iron excess and iron depletion. Comparative transcriptomes between wild type and ΔferS indicated that the mutant was increased in the expression of eight cytochrome P450 genes and those in iron homeostasis, ferroptosis, oxidative stress response, ergosterol biosynthesis, and TCA cycle, compared to wild type. Our data suggested that ΔferS sensed the iron excess and the oxidative stress and, in turn, was up-regulated in the antioxidant-related genes and those in ergosterol biosynthesis and TCA cycle. These increased biological pathways help ΔferS grow and germinate faster than the wild type and caused higher insect mortality than the wild type in the early phase of infection.
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11
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Kang S, Seo H, Lee MG, Yun CW. Regulation of Copper Metabolism by Nitrogen Utilization in Saccharomyces cerevisiae. J Fungi (Basel) 2021; 7:jof7090756. [PMID: 34575794 PMCID: PMC8469692 DOI: 10.3390/jof7090756] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 09/03/2021] [Accepted: 09/10/2021] [Indexed: 11/17/2022] Open
Abstract
To understand the relationship between carbon or nitrogen utilization and iron homeostasis, we performed an iron uptake assay with several deletion mutants with partial defects in carbon or nitrogen metabolism. Among them, some deletion mutants defective in carbon metabolism partially and the MEP2 deletion mutant showed lower iron uptake activity than the wild type. Mep2 is known as a high-affinity ammonia transporter in Saccharomyces cerevisiae. Interestingly, we found that nitrogen starvation resulted in lower iron uptake activity than that of wild-type cells without downregulation of the genes involved in the high-affinity iron uptake system FET3/FTR1. However, the gene expression of FRE1 and CTR1 was downregulated by nitrogen starvation. The protein level of Ctr1 was also decreased by nitrogen starvation, and addition of copper to the nitrogen starvation medium partially restored iron uptake activity. However, the expression of MAC1, which is a copper-responsive transcriptional activator, was not downregulated by nitrogen starvation at the transcriptional level but was highly downregulated at the translational level. Mac1 was downregulated dramatically under nitrogen starvation, and treatment with MG132, which is an inhibitor of proteasome-dependent protein degradation, partially attenuated the downregulation of Mac1. Taken together, these results suggest that nitrogen starvation downregulates the high-affinity iron uptake system by degrading Mac1 in a proteasome-dependent manner and eventually downregulates copper metabolism.
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Affiliation(s)
| | | | | | - Cheol-Won Yun
- Correspondence: ; Tel.: +82-2-3290-3456; Fax: +82-2-927-9028
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12
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Abstract
Metal ions are essential to all living cells, as they can serve as cofactors of enzymes to drive catalysis of biochemical reactions. We present a constraint-based model of yeast that relates metabolism with metal ions via enzymes. The model is able to capture responses of metabolism and gene expression upon iron depletion, suggesting that yeast cells allocate iron resource in the way abiding to optimization principles. Interestingly, the model predicts up-regulation of several iron-containing enzymes that coincide with experiments, which raises the possibility that the decrease in activity due to limited iron could be compensated by elevated enzyme abundance. Moreover, the model paves the way for guiding biosynthesis of high-value compounds (e.g., p-coumaric acid) that relies on iron-containing enzymes. Metal ions are vital to metabolism, as they can act as cofactors on enzymes and thus modulate individual enzymatic reactions. Although many enzymes have been reported to interact with metal ions, the quantitative relationships between metal ions and metabolism are lacking. Here, we reconstructed a genome-scale metabolic model of the yeast Saccharomyces cerevisiae to account for proteome constraints and enzyme cofactors such as metal ions, named CofactorYeast. The model is able to estimate abundances of metal ions binding on enzymes in cells under various conditions, which are comparable to measured metal ion contents in biomass. In addition, the model predicts distinct metabolic flux distributions in response to reduced levels of various metal ions in the medium. Specifically, the model reproduces changes upon iron deficiency in metabolic and gene expression levels, which could be interpreted by optimization principles (i.e., yeast optimizes iron utilization based on metabolic network and enzyme kinetics rather than preferentially targeting iron to specific enzymes or pathways). At last, we show the potential of using the model for understanding cell factories that harbor heterologous iron-containing enzymes to synthesize high-value compounds such as p-coumaric acid. Overall, the model demonstrates the dependence of enzymes on metal ions and links metal ions to metabolism on a genome scale.
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13
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Hsu PC, Lu TC, Hung PH, Jhou YT, Amine AAA, Liao CW, Leu JY. Plastic rewiring of Sef1 transcriptional networks and the potential of non-functional transcription factor binding in facilitating adaptive evolution. Mol Biol Evol 2021; 38:4732-4747. [PMID: 34175931 PMCID: PMC8557406 DOI: 10.1093/molbev/msab192] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Prior and extensive plastic rewiring of a transcriptional network, followed by a functional switch of the conserved transcriptional regulator, can shape the evolution of a new network with diverged functions. The presence of three distinct iron regulatory systems in fungi that use orthologous transcriptional regulators suggests that these systems evolved in that manner. Orthologs of the transcriptional activator Sef1 are believed to be central to how iron regulatory systems developed in fungi, involving gene gain, plastic network rewiring, and switches in regulatory function. We show that, in the protoploid yeast Lachancea kluyveri, plastic rewiring of the L. kluyveri Sef1 (Lk-Sef1) network, together with a functional switch, enabled Lk-Sef1 to regulate TCA cycle genes, unlike Candida albicans Sef1 that mainly regulates iron-uptake genes. Moreover, we observed pervasive nonfunctional binding of Sef1 to its target genes. Enhancing Lk-Sef1 activity resuscitated the corresponding transcriptional network, providing immediate adaptive benefits in changing environments. Our study not only sheds light on the evolution of Sef1-centered transcriptional networks but also shows the adaptive potential of nonfunctional transcription factor binding for evolving phenotypic novelty and diversity.
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Affiliation(s)
- Po-Chen Hsu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC
| | - Tzu-Chiao Lu
- Research Center for Healthy Aging and Institute of New Drug Development, China Medical University, Taichung, Taiwan, ROC.,Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung University, Taipei, Taiwan, ROC
| | - Po-Hsiang Hung
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC.,Genome and Systems Biology Degree Program, National Taiwan University and Academia Sinica, Taipei, Taiwan, ROC
| | - Yu-Ting Jhou
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC
| | - Ahmed A A Amine
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC.,Molecular and Cell Biology Program, Taiwan International Graduate Program, Academia Sinica and Graduate Institute of Life Science, National Defense Medical Center, Taipei, Taiwan, ROC
| | - Chia-Wei Liao
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC
| | - Jun-Yi Leu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC.,Genome and Systems Biology Degree Program, National Taiwan University and Academia Sinica, Taipei, Taiwan, ROC.,Molecular and Cell Biology Program, Taiwan International Graduate Program, Academia Sinica and Graduate Institute of Life Science, National Defense Medical Center, Taipei, Taiwan, ROC
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14
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Mochochoko BM, Ezeokoli OT, Sebolai O, Albertyn J, Pohl CH. Role of the high-affinity reductive iron acquisition pathway of Candida albicans in prostaglandin E2 production, virulence, and interaction with Pseudomonas aeruginosa. Med Mycol 2021; 59:869-881. [PMID: 33862618 DOI: 10.1093/mmy/myab015] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 01/06/2021] [Accepted: 03/03/2021] [Indexed: 02/06/2023] Open
Abstract
Components of the iron reductive pathway of Candida albicans have been implicated in the production of prostaglandin E2 (PGE2) and virulence. However, it is unknown whether other components of this pathway influence PGE2. We investigated the role of the iron reductive pathway of C. albicans in biofilm formation, PGE2 production, and virulence in Caenorhabditis elegans. Additionally, as the co-occurrence of C. albicans and Pseudomonas aeruginosa in host tissues is frequent and involves competition for host-associated iron, we examined the effects of this interaction. Deletion of multicopper oxidase gene, FET99, and iron permease genes, FTH1 and FTH2, affected biofilm metabolic activity, and for the FTH2 mutant, also biofilm morphology. Deletion of CCC1 (vacuolar iron transporter) and CCC2 (P-type ATPase copper importer) also influenced biofilm morphology. For PGE2 production, deletion of FET99, FTH1, FTH2, CCC1, and CCC2 caused a significant reduction by monomicrobial biofilms, while FTH2deletion caused the highest reduction in polymicrobial biofilms. URA3 positive mutants of FET99 and FTH2 demonstrated attenuated virulence in C. elegans, potentially due to the inability of mutants to form hyphae in vivo. Deductively, the role of the iron reductive pathway in PGE2 synthesis is indirect, possibly due to their role in iron homeostasis. LAY SUMMARY Iron uptake is vital for disease-causing microbes like Candida albicans. Using strains deficient in some iron-uptake genes, we show that iron-uptake genes, especially FET99 and FTH2, play a role in biofilm formation, prostaglandin production, and virulence in the nematode infection model.
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Affiliation(s)
- Bonang M Mochochoko
- Pathogenic Yeast Research Group, Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein 9300, South Africa
| | - Obinna T Ezeokoli
- Pathogenic Yeast Research Group, Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein 9300, South Africa
| | - Olihile Sebolai
- Pathogenic Yeast Research Group, Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein 9300, South Africa
| | - Jacobus Albertyn
- Pathogenic Yeast Research Group, Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein 9300, South Africa
| | - Carolina H Pohl
- Pathogenic Yeast Research Group, Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein 9300, South Africa
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15
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Amorim-Vaz S, Coste AT, Tran VDT, Pagni M, Sanglard D. Function Analysis of MBF1, a Factor Involved in the Response to Amino Acid Starvation and Virulence in Candida albicans. FRONTIERS IN FUNGAL BIOLOGY 2021; 2:658899. [PMID: 37744106 PMCID: PMC10512259 DOI: 10.3389/ffunb.2021.658899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 02/15/2021] [Indexed: 09/26/2023]
Abstract
Candida albicans is a commensal of human mucosae, but also one of the most common fungal pathogens of humans. Systemic infections caused by this fungus, mostly affecting immunocompromised patients, are associated to fatality rates as high as 50% despite the available treatments. In order to improve this situation, it is necessary to fully understand how C. albicans is able to cause disease and how it copes with the host defenses. Our previous studies have revealed the importance of the C. albicans gene MBF1 in virulence and ability to colonize internal organs of mammalian and insect hosts. MBF1 encodes a putative transcriptional regulator, and as such it likely has an impact in the regulation of C. albicans gene expression during host infection. Here, recent advances in RNA-seq technologies were used to obtain a detailed analysis of the impact of MBF1 on C. albicans gene expression both in vitro and during infection. MBF1 was involved in the regulation of several genes with a role in glycolysis and response to stress, particularly to nutritional stress. We also investigated whether an interaction existed between MBF1 and GCN4, a master regulator of response to starvation, and found that both genes were needed for resistance to amino acid starvation, suggesting some level of interaction between the two. Reinforcing this idea, we showed that the proteins encoded by both genes could interact. Consistent with the role of MBF1 in virulence, we also established that GCN4 was necessary for virulence in the mouse model of systemic infection as well as in the Galleria mellonella infection model.
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Affiliation(s)
- Sara Amorim-Vaz
- Institute of Microbiology, Lausanne University Hospital, Lausanne, Switzerland
| | - Alix T. Coste
- Institute of Microbiology, Lausanne University Hospital, Lausanne, Switzerland
| | - Van Du T. Tran
- Vital-IT Group, SIB Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Marco Pagni
- Vital-IT Group, SIB Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Dominique Sanglard
- Institute of Microbiology, Lausanne University Hospital, Lausanne, Switzerland
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16
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Choudhury MJA, Trevelyan PMJ, Boswell GP. Mathematical modelling of fungi-initiated siderophore-iron interactions. MATHEMATICAL MEDICINE AND BIOLOGY : A JOURNAL OF THE IMA 2020; 37:515-550. [PMID: 32666102 DOI: 10.1093/imammb/dqaa008] [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: 06/19/2019] [Revised: 05/14/2020] [Accepted: 06/14/2020] [Indexed: 06/11/2023]
Abstract
Nearly all life forms require iron to survive and function. Microorganisms utilize a number of mechanisms to acquire iron including the production of siderophores, which are organic compounds that combine with ferric iron into forms that are easily absorbed by the microorganism. There has been significant experimental investigation into the role, distribution and function of siderophores in fungi but until now no predictive tools have been developed to qualify or quantify fungi-initiated siderophore-iron interactions. In this investigation, we construct the first mathematical models of siderophore function related to fungi. Initially, a set of partial differential equations are calibrated and integrated numerically to generate quantitative predictions on the spatio-temporal distributions of siderophores and related populations. This model is then reduced to a simpler set of equations that are solved algebraically giving rise to solutions that predict the distributions of siderophores and resultant compounds. These algebraic results require the calculation of zeros of cross products of Bessel functions and thus new algebraic expansions are derived for a variety of different cases that are in agreement with numerically computed values. The results of the modelling are consistent with experimental data while the analysis provides new quantitative predictions on the time scales involved between siderophore production and iron uptake along with how the total amount of iron acquired by the fungus depends on its environment. The implications to bio-technological applications are briefly discussed.
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Affiliation(s)
- M Jabed A Choudhury
- Department of Mathematics and Statistics, University of South Wales, Pontypridd, CF37 1DL, UK
| | - Philip M J Trevelyan
- Department of Mathematics and Statistics, University of South Wales, Pontypridd, CF37 1DL, UK
| | - Graeme P Boswell
- Department of Mathematics and Statistics, University of South Wales, Pontypridd, CF37 1DL, UK
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17
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Misslinger M, Hortschansky P, Brakhage AA, Haas H. Fungal iron homeostasis with a focus on Aspergillus fumigatus. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1868:118885. [PMID: 33045305 DOI: 10.1016/j.bbamcr.2020.118885] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/15/2020] [Accepted: 10/01/2020] [Indexed: 02/08/2023]
Abstract
To maintain iron homeostasis, fungi have to balance iron acquisition, storage, and utilization to ensure sufficient supply and to avoid toxic excess of this essential trace element. As pathogens usually encounter iron limitation in the host niche, this metal plays a particular role during virulence. Siderophores are iron-chelators synthesized by most, but not all fungal species to sequester iron extra- and intracellularly. In recent years, the facultative human pathogen Aspergillus fumigatus has become a model for fungal iron homeostasis of siderophore-producing fungal species. This article summarizes the knowledge on fungal iron homeostasis and its links to virulence with a focus on A. fumigatus. It covers mechanisms for iron acquisition, storage, and detoxification, as well as the modes of transcriptional iron regulation and iron sensing in A. fumigatus in comparison to other fungal species. Moreover, potential translational applications of the peculiarities of fungal iron metabolism for treatment and diagnosis of fungal infections is addressed.
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Affiliation(s)
- Matthias Misslinger
- Institute of Molecular Biology - Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Peter Hortschansky
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (HKI), Jena, Germany
| | - Axel A Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (HKI), Jena, Germany; Department Microbiology and Molecular Biology, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Hubertus Haas
- Institute of Molecular Biology - Biocenter, Medical University of Innsbruck, Innsbruck, Austria.
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18
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Ramos-Alonso L, Romero AM, Martínez-Pastor MT, Puig S. Iron Regulatory Mechanisms in Saccharomyces cerevisiae. Front Microbiol 2020; 11:582830. [PMID: 33013818 PMCID: PMC7509046 DOI: 10.3389/fmicb.2020.582830] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 08/20/2020] [Indexed: 12/21/2022] Open
Abstract
Iron is an essential micronutrient for all eukaryotic organisms because it participates as a redox cofactor in many cellular processes. However, excess iron can damage cells since it promotes the generation of reactive oxygen species. The budding yeast Saccharomyces cerevisiae has been used as a model organism to study the adaptation of eukaryotic cells to changes in iron availability. Upon iron deficiency, yeast utilizes two transcription factors, Aft1 and Aft2, to activate the expression of a set of genes known as the iron regulon, which are implicated in iron uptake, recycling and mobilization. Moreover, Aft1 and Aft2 activate the expression of Cth2, an mRNA-binding protein that limits the expression of genes encoding for iron-containing proteins or that participate in iron-using processes. Cth2 contributes to prioritize iron utilization in particular pathways over other highly iron-consuming and non-essential processes including mitochondrial respiration. Recent studies have revealed that iron deficiency also alters many other metabolic routes including amino acid and lipid synthesis, the mitochondrial retrograde response, transcription, translation and deoxyribonucleotide synthesis; and activates the DNA damage and general stress responses. At high iron levels, the yeast Yap5, Msn2, and Msn4 transcription factors activate the expression of a vacuolar iron importer called Ccc1, which is the most important high-iron protecting factor devoted to detoxify excess cytosolic iron that is stored into the vacuole for its mobilization upon scarcity. The complete sequencing and annotation of many yeast genomes is starting to unveil the diversity and evolution of the iron homeostasis network in this species.
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Affiliation(s)
- Lucía Ramos-Alonso
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Valencia, Spain
| | - Antonia María Romero
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Valencia, Spain
| | | | - Sergi Puig
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Valencia, Spain
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19
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Wu PC, Chen CW, Choo CYL, Chen YK, Yago JI, Chung KR. Biotin biosynthesis affected by the NADPH oxidase and lipid metabolism is required for growth, sporulation and infectivity in the citrus fungal pathogen Alternaria alternata. Microbiol Res 2020; 241:126566. [PMID: 33032167 DOI: 10.1016/j.micres.2020.126566] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/30/2020] [Accepted: 07/23/2020] [Indexed: 02/06/2023]
Abstract
The tangerine pathotype of Alternaria alternata affects many citrus cultivars, resulting in yield losses. The capability to produce the host-selective toxin and cell-wall-degrading enzymes and to mitigate toxic reactive oxygen species is crucial for A. alternata pathogenesis to citrus. Little is known about nutrient availability within citrus tissues to the fungal pathogen. In the present study, we assess the infectivity of a biotin deficiency mutant (ΔbioB) and a complementation strain (CP36) on citrus leaves to determine how biotin impacts A. alternata pathogenesis. Growth and sporulation of ΔbioB are highly dependent on biotin. ΔbioB retains its ability to acquire and transport biotin from the surrounding environment. Growth deficiency of ΔbioB can also be partially restored by the presence of oleic acid or Tween 20, suggesting the requirement of biotin in lipid metabolism. Experimental evidence indicates that de novo biotin biosynthesis is regulated by the NADPH oxidase, implicating in the production of H2O2, and is affected by the function of peroxisomes. Three genes involved in the biosynthesis of biotin are clustered and co-regulated by biotin indicating a transcriptional feedback loop activation. Infectivity assays using fungal mycelium reveal that ΔbioB cultured on medium without biotin fails to infect citrus leaves; co-inoculation with biotin fully restores infectivity. The CP36 strain re-expressing a functional copy of bioB displays wild-type growth, sporulation and virulence. Taken together, we conclude that the attainability or accessibility of biotin is extremely restricted in citrus cells. A. alternata must be able to synthesize biotin in order to utilize nutrients for growth, colonization and development within the host.
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Affiliation(s)
- Pei-Ching Wu
- Department of Plant Pathology, College of Agriculture and Natural Resources, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Chia-Wen Chen
- Department of Plant Pathology, College of Agriculture and Natural Resources, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Celine Yen Ling Choo
- Department of Plant Pathology, College of Agriculture and Natural Resources, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Yu-Kun Chen
- Department of Plant Pathology, College of Agriculture and Natural Resources, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Jonar I Yago
- Plant Science Department, College of Agriculture, Nueva Vizcaya State University, Bayombong, Nueva Vizcaya, 3700, Philippines
| | - Kuang-Ren Chung
- Department of Plant Pathology, College of Agriculture and Natural Resources, National Chung Hsing University, Taichung, 40227, Taiwan.
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20
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Martínez-Pastor MT, Puig S. Adaptation to iron deficiency in human pathogenic fungi. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1867:118797. [PMID: 32663505 DOI: 10.1016/j.bbamcr.2020.118797] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 06/13/2020] [Accepted: 07/05/2020] [Indexed: 02/08/2023]
Abstract
Iron is an essential micronutrient for virtually all eukaryotic organisms and plays a central role during microbial infections. Invasive fungal diseases are associated with strikingly high rates of mortality, but their impact on human health is usually underestimated. Upon a fungal infection, hosts restrict iron availability in order to limit the growth and virulence of the pathogen. Here, we use two model yeasts, Saccharomyces cerevisiae and Schizosaccharomyces pombe, to delve into the response to iron deficiency of human fungal pathogens, such as Candida glabrata, Candida albicans, Aspergillus fumigatus and Cryptococcus neoformans. Fungi possess common and species-specific mechanisms to acquire iron and to control the response to iron limitation. Upon iron scarcity, fungi activate a wide range of elegant strategies to capture and import exogenous iron, mobilize iron from intracellular stores, and modulate their metabolism to economize and prioritize iron utilization. Hence, iron homeostasis genes represent remarkable virulence factors that can be used as targets for the development of novel antifungal treatments.
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Affiliation(s)
| | - Sergi Puig
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Paterna, Valencia, Spain.
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21
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Perea-García A, Miró P, Jiménez-Lorenzo R, Martínez-Pastor MT, Puig S. Sequential recruitment of the mRNA decay machinery to the iron-regulated protein Cth2 in Saccharomyces cerevisiae. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1863:194595. [PMID: 32565401 DOI: 10.1016/j.bbagrm.2020.194595] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/25/2020] [Accepted: 06/10/2020] [Indexed: 01/24/2023]
Abstract
Post-transcriptional factors importantly contribute to the rapid and coordinated expression of the multiple genes required for the adaptation of living organisms to environmental stresses. In the model eukaryote Saccharomyces cerevisiae, a conserved mRNA-binding protein, known as Cth2, modulates the metabolic response to iron deficiency. Cth2 is a tandem zinc-finger (TZF)-containing protein that co-transcriptionally binds to adenine/uracil-rich elements (ARE) present in the 3'-untranslated region of iron-related mRNAs to promote their turnover. The nuclear binding of Cth2 to mRNAs via its TZFs is indispensable for its export to the cytoplasm. Although Cth2 nucleocytoplasmic transport is essential for its regulatory function, little is known about the recruitment of the mRNA degradation machinery. Here, we investigate the sequential assembly of mRNA decay factors during Cth2 shuttling. By using an enzymatic in vivo proximity assay called M-track, we show that Cth2 associates to the RNA helicase Dhh1 and the deadenylase Pop2/Caf1 before binding to its target mRNAs. The recruitment of Dhh1 to Cth2 requires the integrity of the Ccr4-Pop2 deadenylase complex, whereas the interaction between Cth2 and Pop2 needs Ccr4 but not Dhh1. M-track assays also show that Cth2-binding to ARE-containing mRNAs is necessary for the interaction between Cth2 and the exonuclease Xrn1. The importance of these interactions is highlighted by the specific growth defect in iron-deficient conditions displayed by cells lacking Dhh1, Pop2, Ccr4 or Xrn1. These results exemplify the stepwise process of assembly of different mRNA decay factors onto an mRNA-binding protein during the mechanism of post-transcriptional regulation.
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Affiliation(s)
- Ana Perea-García
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Paterna (Valencia), Spain
| | - Pilar Miró
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Paterna (Valencia), Spain
| | - Rafael Jiménez-Lorenzo
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Paterna (Valencia), Spain
| | | | - Sergi Puig
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Paterna (Valencia), Spain.
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22
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Tripathi A, Liverani E, Tsygankov AY, Puri S. Iron alters the cell wall composition and intracellular lactate to affect Candida albicans susceptibility to antifungals and host immune response. J Biol Chem 2020; 295:10032-10044. [PMID: 32503842 DOI: 10.1074/jbc.ra120.013413] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 05/27/2020] [Indexed: 12/19/2022] Open
Abstract
Fungal pathogen Candida albicans has a complex cell wall consisting of an outer layer of mannans and an inner layer of β-glucans and chitin. The fungal cell wall is the primary target for antifungals and is recognized by host immune cells. Environmental conditions such as carbon sources, pH, temperature, and oxygen tension can modulate the fungal cell wall architecture. Cellular signaling pathways, including the mitogen-activated protein kinase (MAPK) pathways, are responsible for sensing environmental cues and mediating cell wall alterations. Although iron has recently been shown to affect β-1,3-glucan exposure on the cell wall, we report here that iron changes the composition of all major C. albicans cell wall components. Specifically, high iron decreased the levels of mannans (including phosphomannans) and chitin; and increased β-1,3-glucan levels. These changes increased the resistance of C. albicans to cell wall-perturbing antifungals. Moreover, high iron cells exhibited adequate mitochondrial functioning; leading to a reduction in accumulation of lactate that signals through the transcription factor Crz1 to induce β-1,3-glucan masking in C. albicans We show here that iron-induced changes in β-1,3-glucan exposure are lactate-dependent; and high iron causes β-1,3-glucan exposure by preventing lactate-induced, Crz1-mediated inhibition of activation of the fungal MAPK Cek1. Furthermore, despite exhibiting enhanced antifungal resistance, high iron C. albicans cells had reduced survival upon phagocytosis by macrophages. Our results underscore the role of iron as an environmental signal in multiple signaling pathways that alter cell wall architecture in C. albicans, thereby affecting its survival upon exposure to antifungals and host immune response.
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Affiliation(s)
- Aparna Tripathi
- Oral Microbiome Research Laboratory, Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania, USA
| | - Elisabetta Liverani
- Sol Sherry Thrombosis Research Center, Temple University School of Medicine, Temple University Hospital, Philadelphia, Pennsylvania, USA
| | - Alexander Y Tsygankov
- Sol Sherry Thrombosis Research Center, Temple University School of Medicine, Temple University Hospital, Philadelphia, Pennsylvania, USA.,Department of Microbiology and Immunology, Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Sumant Puri
- Oral Microbiome Research Laboratory, Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania, USA
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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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24
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Machinery for fungal heme acquisition. Curr Genet 2020; 66:703-711. [PMID: 32185489 DOI: 10.1007/s00294-020-01067-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 03/04/2020] [Accepted: 03/05/2020] [Indexed: 02/07/2023]
Abstract
Iron is essential for nearly all aerobic organisms. One source of iron in nature is in the form of heme. Due to its critical physiological importance as a cofactor for several enzymes, organisms have evolved various means to secure heme for their needs. In the case of heme prototrophs, these organisms possess a highly conserved eight-step biosynthetic pathway. Another means used by many organisms is to acquire heme from external sources. As opposed to the knowledge of enzymes responsible for heme biosynthesis, the nature of the players and mechanisms involved in the acquisition of exogenous heme is limited. This review focuses on a description of newly discovered proteins that have novel functions in heme assimilation in the model organism Schizosaccharomyces pombe. This tractable model allows the use of the power of genetics to selectively block heme biosynthesis, setting conditions to investigate the mechanisms by which external heme is taken up by the cells. Studies have revealed that S. pombe possesses two independent heme uptake systems that require Shu1 and Str3, respectively. Heme-bound iron is captured by Shu1 at the cell surface, triggering its internalization to the vacuole with the aid of ubiquitinated proteins and the ESCRT machinery. In the case of the plasma membrane transporter Str3, it promotes cellular heme import in cells lacking Shu1. The discovery of these two pathways may contribute to gain novel insights into the mechanisms whereby fungi assimilate heme, which is an essentially biological process for their ability to invade and colonize new niches.
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25
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Brault A, Labbé S. Iron deficiency leads to repression of a non-canonical methionine salvage pathway in Schizosaccharomyces pombe. Mol Microbiol 2020; 114:46-65. [PMID: 32090388 DOI: 10.1111/mmi.14495] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 02/19/2020] [Accepted: 02/19/2020] [Indexed: 12/31/2022]
Abstract
The methionine salvage pathway (MSP) regenerates methionine from 5'-methylthioadenosine (MTA). Aerobic MSP consists of six enzymatic steps. The mug14+ and adi1+ genes that are involved in the third and fifth steps of the pathway are repressed when Schizosaccharomyces pombe undergoes a transition from high- to low-iron conditions. Results consistently show that methionine auxotrophic cells (met6Δ) require iron for growth in the presence of MTA as the sole source of methionine. Inactivation of the iron-using protein Adi1 leads to defects in the utilization of MTA. In the case of the third step of the pathway, co-expression of two distinct proteins, Mta3 and Mde1, is required. These proteins are interdependent to rescue MTA-dependent growth deficit of met6Δ cells. Coimmunoprecipitation experiments showed that Mta3 is a binding partner of Mde1. Meiotic met6Δ cells co-expressing mta3+ and mde1+ or mta3+ and mug14+ produce comparable levels of spores in the presence of MTA, revealing that Mde1 and Mug14 share a common function when co-expressed with Mta3 in sporulating cells. In sum, our findings unveil several novel features of MSP, especially with respect to its regulation by iron and the discovery of a non-canonical third enzymatic step in the fission yeast.
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Affiliation(s)
- Ariane Brault
- Département de Biochimie et de Génomique Fonctionnelle, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Simon Labbé
- Département de Biochimie et de Génomique Fonctionnelle, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada
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The yeast Aft1 transcription factor activates ribonucleotide reductase catalytic subunit RNR1 in response to iron deficiency. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1863:194522. [PMID: 32147528 DOI: 10.1016/j.bbagrm.2020.194522] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 02/25/2020] [Accepted: 03/01/2020] [Indexed: 12/18/2022]
Abstract
Eukaryotic ribonucleotide reductases are iron-dependent enzymes that catalyze the rate-limiting step in the de novo synthesis of deoxyribonucleotides. Multiple mechanisms regulate the activity of ribonucleotide reductases in response to genotoxic stresses and iron deficiency. Upon iron starvation, the Saccharomyces cerevisiae Aft1 transcription factor specifically binds to iron-responsive cis elements within the promoter of a group of genes, known as the iron regulon, activating their transcription. Members of the iron regulon participate in iron acquisition, mobilization and recycling, and trigger a genome-wide metabolic remodeling of iron-dependent pathways. Here, we describe a mechanism that optimizes the activity of yeast ribonucleotide reductase when iron is scarce. We demonstrate that Aft1 and the DNA-binding protein Ixr1 enhance the expression of the gene encoding for its catalytic subunit, RNR1, in response to iron limitation, leading to an increase in both mRNA and protein levels. By mutagenesis of the Aft1-binding sites within RNR1 promoter, we conclude that RNR1 activation by iron depletion is important for Rnr1 protein and deoxyribonucleotide synthesis. Remarkably, Aft1 also activates the expression of IXR1 upon iron scarcity through an iron-responsive element located within its promoter. These results provide a novel mechanism for the direct activation of ribonucleotide reductase function by the iron-regulated Aft1 transcription factor.
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Romero AM, Ramos-Alonso L, Alepuz P, Puig S, Martínez-Pastor MT. Global translational repression induced by iron deficiency in yeast depends on the Gcn2/eIF2α pathway. Sci Rep 2020; 10:233. [PMID: 31937829 PMCID: PMC6959253 DOI: 10.1038/s41598-019-57132-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 12/16/2019] [Indexed: 11/09/2022] Open
Abstract
Iron is an essential element for all eukaryotic organisms because it participates as a redox active cofactor in a wide range of biological processes, including protein synthesis. Translation is probably the most energy consuming process in cells. Therefore, one of the initial responses of eukaryotic cells to stress or nutrient limitation is the arrest of mRNA translation. In first instance, the budding yeast Saccharomyces cerevisiae responds to iron deficiency by activating iron acquisition and remodeling cellular metabolism in order to prioritize essential over non-essential iron-dependent processes. We have determined that, despite a global decrease in transcription, mRNA translation is actively maintained during a short-term exposure to iron scarcity. However, a more severe iron deficiency condition induces a global repression of translation. Our results indicate that the Gcn2-eIF2α pathway limits general translation at its initiation step during iron deficiency. This bulk translational inhibition depends on the uncharged tRNA sensing Gcn1-Gcn20 complex. The involvement of the Gcn2-eIF2α pathway in the response to iron deficiency highlights its central role in the eukaryotic response to stress or nutritional deprivation, which is conserved from yeast to mammals.
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Affiliation(s)
- Antonia María Romero
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Catedrático Agustín Escardino 7, E-46980, Paterna, Valencia, Spain
| | - Lucía Ramos-Alonso
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Catedrático Agustín Escardino 7, E-46980, Paterna, Valencia, Spain
| | - Paula Alepuz
- Departamento de Bioquímica y Biología Molecular, Universitat de València, Doctor Moliner 50, E-46100, Burjassot, Valencia, Spain.,ERI Biotecmed, Universitat de València, Doctor Moliner 50, E-46100, Burjassot, Valencia, Spain
| | - Sergi Puig
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Catedrático Agustín Escardino 7, E-46980, Paterna, Valencia, Spain.
| | - María Teresa Martínez-Pastor
- Departamento de Bioquímica y Biología Molecular, Universitat de València, Doctor Moliner 50, E-46100, Burjassot, Valencia, Spain.
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28
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Duval C, Macabiou C, Garcia C, Lesuisse E, Camadro JM, Auchère F. The adaptive response to iron involves changes in energetic strategies in the pathogen Candida albicans. Microbiologyopen 2019; 9:e970. [PMID: 31788966 PMCID: PMC7002100 DOI: 10.1002/mbo3.970] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 10/22/2019] [Accepted: 10/29/2019] [Indexed: 12/19/2022] Open
Abstract
Candida albicans is an opportunist pathogen responsible for a large spectrum of infections, from superficial mycosis to systemic diseases known as candidiasis. Its ability to grow in different morphological forms, such as yeasts or filamentous hyphae, contributes to its survival in diverse microenvironments. Iron uptake has been associated with virulence, and C. albicans has developed elaborate strategies for acquiring iron from its host. In this work, we analyze the metabolic changes in response to changes in iron content in the growth medium and compare C. albicans adaptation to the presence or absence of iron. Functional and morphological studies, correlated to a quantitative proteomic analysis, were performed to assess the specific pathways underlying the response to iron, both in the yeast and filamentous forms. Overall, the results show that the adaptive response to iron is associated with a metabolic remodeling affecting the energetic pathways of the pathogen. This includes changes in the thiol-dependent redox status, the activity of key mitochondrial enzymes and the respiratory chain. Iron deficiency stimulates bioenergetic pathways, whereas iron-rich condition is associated with greater biosynthetic needs, particularly in filamentous forms. Moreover, we found that C. albicans yeast cells have an extraordinary capability to adapt to changes in environmental conditions.
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Affiliation(s)
- Celia Duval
- Laboratoire Mitochondries, Métaux et Stress Oxydant, Institut Jacques Monod, UMR 7592, Université Paris-Diderot/CNRS (USPC), Paris, France
| | - Carole Macabiou
- Laboratoire Mitochondries, Métaux et Stress Oxydant, Institut Jacques Monod, UMR 7592, Université Paris-Diderot/CNRS (USPC), Paris, France
| | - Camille Garcia
- Plateforme Protéomique structurale et fonctionnelle/Spectrométrie de masse, Institut Jacques Monod, UMR 7592, Université Paris-Diderot/CNRS (USPC), Paris, France
| | - Emmanuel Lesuisse
- Laboratoire Mitochondries, Métaux et Stress Oxydant, Institut Jacques Monod, UMR 7592, Université Paris-Diderot/CNRS (USPC), Paris, France
| | - Jean-Michel Camadro
- Laboratoire Mitochondries, Métaux et Stress Oxydant, Institut Jacques Monod, UMR 7592, Université Paris-Diderot/CNRS (USPC), Paris, France
| | - Françoise Auchère
- Laboratoire Mitochondries, Métaux et Stress Oxydant, Institut Jacques Monod, UMR 7592, Université Paris-Diderot/CNRS (USPC), Paris, France
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29
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Ramos-Alonso L, Wittmaack N, Mulet I, Martínez-Garay CA, Fita-Torró J, Lozano MJ, Romero AM, García-Ferris C, Martínez-Pastor MT, Puig S. Molecular strategies to increase yeast iron accumulation and resistance. Metallomics 2019; 10:1245-1256. [PMID: 30137082 DOI: 10.1039/c8mt00124c] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
All eukaryotic organisms rely on iron as an essential micronutrient for life because it participates as a redox-active cofactor in multiple biological processes. However, excess iron can generate reactive oxygen species that damage cellular macromolecules. The low solubility of ferric iron under physiological conditions increases the prevalence of iron deficiency anemia. A common strategy to treat iron deficiency consists of dietary iron supplementation. The baker's yeast Saccharomyces cerevisiae is used as a model eukaryotic organism, but also as a feed supplement. In response to iron deficiency, the yeast Aft1 transcription factor activates cellular iron acquisition. However, when constitutively active, Aft1 inhibits growth probably due to iron toxicity. In this report, we have studied the consequences of using hyperactive AFT1 alleles, including AFT1-1UP, to increase yeast iron accumulation. We first characterized the iron sensitivity of cells expressing different constitutively active AFT1 alleles. We rescued the high iron sensitivity conferred by the AFT1 alleles by deleting the sphingolipid signaling kinase YPK1. We observed that the deletion of YPK1 exerts different effects on iron accumulation depending on the AFT1 allele and the environmental iron. Moreover, we determined that the impairment of the high-affinity iron transport system partially rescues the high iron toxicity of AFT1-1UP-expressing cells. Finally, we observed that AFT1-1UP inhibits oxygen consumption through activation of the RNA-binding protein Cth2. Deletion of CTH2 partially rescues the AFT1-1UP negative respiratory effect. Collectively, these results contribute to understand how the Aft1 transcription factor functions and the multiple consequences derived from its constitutive activation.
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Affiliation(s)
- Lucía Ramos-Alonso
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Paterna, Valencia, Spain.
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30
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Hu YM, Boehm DM, Chung H, Wilson S, Bird AJ. Zinc-dependent activation of the Pho8 alkaline phosphatase in Schizosaccharomyces pombe. J Biol Chem 2019; 294:12392-12404. [PMID: 31239353 DOI: 10.1074/jbc.ra119.007371] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 06/20/2019] [Indexed: 01/23/2023] Open
Abstract
Genome-wide analyses have revealed that during metal ion starvation, many cells undergo programmed changes in their transcriptome or proteome that lower the levels of abundant metalloproteins, conserving metal ions for more critical functions. Here we investigated how changes in cellular zinc status affect the expression and activity of the zinc-requiring Pho8 alkaline phosphatase from fission yeast (Schizosaccharomyces pombe). In S. pombe, Pho8 is a membrane-tethered and processed glycoprotein that resides in the vacuole. Using alkaline phosphatase activity assays along with various biochemical analyses, we found that Pho8 is active when zinc is plentiful and inactive when zinc is limited. Although Pho8 activity depended on zinc, we also found that higher levels of pho8 mRNAs and Pho8 protein accumulate in zinc-deficient cells. To gain a better understanding of the inverse relationship between pho8 mRNA levels and Pho8 activity, we examined the effects of zinc on the stability and processing of the Pho8 protein. We show that Pho8 is processed regardless of zinc status and that mature Pho8 accumulates under all conditions. We also noted that alkaline phosphatase activity is rapidly restored when zinc is resupplied to cells, even in the presence of the protein synthesis inhibitor cycloheximide. Our results suggest that S. pombe cells maintain inactive pools of Pho8 proteins under low-zinc conditions and that these pools facilitate rapid restoration of Pho8 activity when zinc ions become available.
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Affiliation(s)
- Ya-Mei Hu
- Department of Human Nutrition, Ohio State University, Columbus, Ohio 43210
| | - Derek M Boehm
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210
| | - Hak Chung
- Ohio State University Interdisciplinary Nutrition Program, Ohio State University, Columbus, Ohio 43210
| | - Stevin Wilson
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210
| | - Amanda J Bird
- Department of Human Nutrition, Ohio State University, Columbus, Ohio 43210; Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210; Center for RNA Biology, Ohio State University, Columbus, Ohio 43210.
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31
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Daghino S, Di Vietro L, Petiti L, Martino E, Dallabona C, Lodi T, Perotto S. Yeast expression of mammalian Onzin and fungal FCR1 suggests ancestral functions of PLAC8 proteins in mitochondrial metabolism and DNA repair. Sci Rep 2019; 9:6629. [PMID: 31036870 PMCID: PMC6488628 DOI: 10.1038/s41598-019-43136-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 04/11/2019] [Indexed: 01/07/2023] Open
Abstract
The cysteine-rich PLAC8 domain of unknown function occurs in proteins found in most Eukaryotes. PLAC8-proteins play important yet diverse roles in different organisms, such as control of cell proliferation in animals and plants or heavy metal resistance in plants and fungi. Mammalian Onzin can be either pro-proliferative or pro-apoptotic, depending on the cell type, whereas fungal FCR1 confers cadmium tolerance. Despite their different role in different organisms, we hypothesized common ancestral functions linked to the PLAC8 domain. To address this hypothesis, and to investigate the molecular function of the PLAC8 domain, murine Onzin and fungal FCR1 were expressed in the PLAC8-free yeast Saccharomyces cerevisiae. The two PLAC8-proteins localized in the nucleus and induced almost identical phenotypes and transcriptional changes when exposed to cadmium stress. Like FCR1, Onzin also reduced DNA damage and increased cadmium tolerance by a DUN1-dependent pathway. Both proteins activated transcription of ancient mitochondrial pathways such as leucine and Fe-S cluster biosynthesis, known to regulate cell proliferation and DNA repair in yeast. These results strongly suggest a common ancestral function of PLAC8 proteins and open new perspectives to understand the role of the PLAC8 domain in the cellular biology of Eukaryotes.
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Affiliation(s)
- Stefania Daghino
- Department of Life Sciences and Systems Biology, University of Torino, Viale Mattioli 25, 10125, Torino, Italy
| | - Luigi Di Vietro
- Department of Life Sciences and Systems Biology, University of Torino, Viale Mattioli 25, 10125, Torino, Italy.,Department of Biochemistry and Biotechnology, Bayer SAS, centre de recherche "la Dargoire" 14, impasse Pierre Baizet CS 99163, 69263, Lyon, CEDEX 09, France
| | - Luca Petiti
- Italian Institute for Genomic Medicine, via Nizza 52, 10126, Torino, Italy
| | - Elena Martino
- Department of Life Sciences and Systems Biology, University of Torino, Viale Mattioli 25, 10125, Torino, Italy
| | - Cristina Dallabona
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Viale delle Scienze 11/A, 43124, Parma, Italy
| | - Tiziana Lodi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Viale delle Scienze 11/A, 43124, Parma, Italy
| | - Silvia Perotto
- Department of Life Sciences and Systems Biology, University of Torino, Viale Mattioli 25, 10125, Torino, Italy.
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32
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Zeng J, Xu T, Cao L, Tong C, Zhang X, Luo D, Han S, Pang P, Fu W, Yan J, Liu X, Zhu Y. The Role of Iron Competition in the Antagonistic Action of the Rice Endophyte Streptomyces sporocinereus OsiSh-2 Against the Pathogen Magnaporthe oryzae. MICROBIAL ECOLOGY 2018; 76:1021-1029. [PMID: 29679119 DOI: 10.1007/s00248-018-1189-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Accepted: 04/10/2018] [Indexed: 05/13/2023]
Abstract
Rice blast caused by Magnaporthe oryzae severely impacts global rice yield stability. The rice endophyte Streptomyces sporocinereus OsiSh-2, with strong antagonistic activity towards M. oryzae, has been reported in our previous study. To decipher the model of the antagonistic action of OsiSh-2 towards M. oryzae, we compared the iron-capturing abilities of these two strains. The cultivation of OsiSh-2 and a M. oryzae strain under iron-rich and iron-starved conditions showed that M. oryzae depended more on iron supplementation for growth and development than did OsiSh-2. Genomic analysis of the S. sporocinereus and M. oryzae species strains revealed that they might possess different iron acquisition strategies. The actinobacterium OsiSh-2 is likely to favor siderophore utilization compared to the fungus M. oryzae. In addition, protein annotations found that OsiSh-2 contains the highest number of the siderophore biosynthetic gene clusters among the 13 endophytic actinomycete strains and 13 antifungal actinomycete strains that we compared, indicating the prominent siderophore production potential of OsiSh-2. Additionally, we verified that OsiSh-2 could excrete considerably more siderophores than Guy11 under iron-restricted conditions and displayed greater Fe3+-reducing activity during iron-supplemental conditions. Measurements of the iron mobilization between the antagonistic OsiSh-2 and Guy11 showed that the iron concentration is higher around OsiSh-2 than around Guy11. In addition, adding iron near OsiSh-2 could decrease the antagonism of OsiSh-2 towards Guy11. Our study revealed that the antagonistic capacity displayed by OsiSh-2 towards M. oryzae was related to the competition for iron. The highly efficient iron acquisition system of OsiSh-2 may offer valuable insight for the biocontrol of rice blast.
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Affiliation(s)
- Jiarui Zeng
- Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, 410008, Hunan, People's Republic of China
| | - Ting Xu
- Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, 410008, Hunan, People's Republic of China
| | - Lidan Cao
- Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, 410008, Hunan, People's Republic of China
| | - Chunyi Tong
- Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, 410008, Hunan, People's Republic of China
| | - Xuan Zhang
- Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, 410008, Hunan, People's Republic of China
| | - Dingyi Luo
- Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, 410008, Hunan, People's Republic of China
| | - Shuping Han
- Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, 410008, Hunan, People's Republic of China
| | - Pei Pang
- College of Information Science and Engineering, Hunan University, Changsha, 410008, Hunan, People's Republic of China
| | - Weibin Fu
- Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, 410008, Hunan, People's Republic of China
| | - Jindong Yan
- Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, 410008, Hunan, People's Republic of China
| | - Xuanming Liu
- Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, 410008, Hunan, People's Republic of China
| | - Yonghua Zhu
- Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, 410008, Hunan, People's Republic of China.
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33
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Mara P, Fragiadakis GS, Gkountromichos F, Alexandraki D. The pleiotropic effects of the glutamate dehydrogenase (GDH) pathway in Saccharomyces cerevisiae. Microb Cell Fact 2018; 17:170. [PMID: 30384856 PMCID: PMC6211499 DOI: 10.1186/s12934-018-1018-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 10/29/2018] [Indexed: 12/19/2022] Open
Abstract
Ammonium assimilation is linked to fundamental cellular processes that include the synthesis of non-essential amino acids like glutamate and glutamine. In Saccharomyces cerevisiae glutamate can be synthesized from α-ketoglutarate and ammonium through the action of NADP-dependent glutamate dehydrogenases Gdh1 and Gdh3. Gdh1 and Gdh3 are evolutionarily adapted isoforms and cover the anabolic role of the GDH-pathway. Here, we review the role and function of the GDH pathway in glutamate metabolism and we discuss the additional contributions of the pathway in chromatin regulation, nitrogen catabolite repression, ROS-mediated apoptosis, iron deficiency and sphingolipid-dependent actin cytoskeleton modulation in S.cerevisiae. The pleiotropic effects of GDH pathway in yeast biology highlight the importance of glutamate homeostasis in vital cellular processes and reveal new features for conserved enzymes that were primarily characterized for their metabolic capacity. These newly described features constitute insights that can be utilized for challenges regarding genetic engineering of glutamate homeostasis and maintenance of redox balances, biosynthesis of important metabolites and production of organic substrates. We also conclude that the discussed pleiotropic features intersect with basic metabolism and set a new background for further glutamate-dependent applied research of biotechnological interest.
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Affiliation(s)
- P. Mara
- Department of Chemistry, University of Crete, Voutes University Campus, 71003 Heraklion, Crete Greece
- Present Address: Woods Hole Oceanographic Institution, Woods Hole, MA 02543 USA
| | - G. S. Fragiadakis
- Institute of Molecular Biology & Biotechnology, FORTH, Nikolaou Plastira 100 GR-70013, Heraklion, Crete Greece
| | - F. Gkountromichos
- Department of Biology, University of Crete, Voutes University Campus, 71003 Heraklion, Crete Greece
- Faculty of Biology, Biocenter, Ludwig-Maximilians-University of Munich, Großhaderner Str. 2, 82152 Planegg-Martinsried, Germany
| | - D. Alexandraki
- Department of Biology, University of Crete, Voutes University Campus, 71003 Heraklion, Crete Greece
- Institute of Molecular Biology & Biotechnology, FORTH, Nikolaou Plastira 100 GR-70013, Heraklion, Crete Greece
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34
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Yien YY, Shi J, Chen C, Cheung JTM, Grillo AS, Shrestha R, Li L, Zhang X, Kafina MD, Kingsley PD, King MJ, Ablain J, Li H, Zon LI, Palis J, Burke MD, Bauer DE, Orkin SH, Koehler CM, Phillips JD, Kaplan J, Ward DM, Lodish HF, Paw BH. FAM210B is an erythropoietin target and regulates erythroid heme synthesis by controlling mitochondrial iron import and ferrochelatase activity. J Biol Chem 2018; 293:19797-19811. [PMID: 30366982 DOI: 10.1074/jbc.ra118.002742] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 09/11/2018] [Indexed: 01/01/2023] Open
Abstract
Erythropoietin (EPO) signaling is critical to many processes essential to terminal erythropoiesis. Despite the centrality of iron metabolism to erythropoiesis, the mechanisms by which EPO regulates iron status are not well-understood. To this end, here we profiled gene expression in EPO-treated 32D pro-B cells and developing fetal liver erythroid cells to identify additional iron regulatory genes. We determined that FAM210B, a mitochondrial inner-membrane protein, is essential for hemoglobinization, proliferation, and enucleation during terminal erythroid maturation. Fam210b deficiency led to defects in mitochondrial iron uptake, heme synthesis, and iron-sulfur cluster formation. These defects were corrected with a lipid-soluble, small-molecule iron transporter, hinokitiol, in Fam210b-deficient murine erythroid cells and zebrafish morphants. Genetic complementation experiments revealed that FAM210B is not a mitochondrial iron transporter but is required for adequate mitochondrial iron import to sustain heme synthesis and iron-sulfur cluster formation during erythroid differentiation. FAM210B was also required for maximal ferrochelatase activity in differentiating erythroid cells. We propose that FAM210B functions as an adaptor protein that facilitates the formation of an oligomeric mitochondrial iron transport complex, required for the increase in iron acquisition for heme synthesis during terminal erythropoiesis. Collectively, our results reveal a critical mechanism by which EPO signaling regulates terminal erythropoiesis and iron metabolism.
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Affiliation(s)
- Yvette Y Yien
- From the Department of Biological Sciences, University of Delaware, Newark, Delaware 19716, .,the Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Jiahai Shi
- the Whitehead Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Caiyong Chen
- the Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Jesmine T M Cheung
- the Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095
| | - Anthony S Grillo
- the Department of Chemistry and Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Rishna Shrestha
- the Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112
| | - Liangtao Li
- the Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112
| | - Xuedi Zhang
- From the Department of Biological Sciences, University of Delaware, Newark, Delaware 19716
| | - Martin D Kafina
- the Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Paul D Kingsley
- the Center for Pediatric Biomedical Research, Department of Pediatrics, University of Rochester Medical Center, Rochester, New York 14642
| | - Matthew J King
- the Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Julien Ablain
- the Division of Hematology-Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Hojun Li
- the Whitehead Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Leonard I Zon
- the Division of Hematology-Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115.,the Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115, and
| | - James Palis
- the Center for Pediatric Biomedical Research, Department of Pediatrics, University of Rochester Medical Center, Rochester, New York 14642
| | - Martin D Burke
- the Department of Chemistry and Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Daniel E Bauer
- the Division of Hematology-Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115.,the Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115, and
| | - Stuart H Orkin
- the Division of Hematology-Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115.,the Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115, and
| | - Carla M Koehler
- the Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095
| | - John D Phillips
- the Division of Hematology and Hematologic Malignancy, University of Utah School of Medicine, Salt Lake City, Utah 84112
| | - Jerry Kaplan
- the Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112
| | - Diane M Ward
- the Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112
| | - Harvey F Lodish
- the Whitehead Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Barry H Paw
- the Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115.,the Division of Hematology-Oncology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115.,the Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115, and
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35
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Abdalla M, Eltayb WA, Yousif A. Comparison of structures among Saccharomyces cerevisiae Grxs proteins. Genes Environ 2018; 40:17. [PMID: 30186535 PMCID: PMC6120076 DOI: 10.1186/s41021-018-0104-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 07/12/2018] [Indexed: 11/11/2022] Open
Abstract
Glutaredoxins (Grxs) comprise a group of glutathione (GSH)-dependent oxidoreductase enzymes that respond to oxidative stress and sustain redox homeostasis. Saccharomyces cerevisiae Grx has a similar interaction patterns through its residues between the residues and the environment. The glutaredoxin domain covers 100% of the entire mature Grx1 and Grx8, while the glutaredoxin domain covers ~ 52% of the entire mature Grx6 and Grx7, which have approximately 74 additional amino acids in their N-terminal regions, whereas Grx3 and Grx4 have two functional domains: glutaredoxin and thioredoxin. We have presented the prediction of disordered regions within these protein sequences. Multiple sequence alignment combined with a phylogenetic tree enabled us to specify the key residues contributing to the differences between Saccharomyces cerevisiae Grxs and the proportion symmetry.
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Affiliation(s)
- Mohnad Abdalla
- 1Faculty of Science and Technology, Omdurman Islamic University, Omdurman, Sudan.,2School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027 People's Republic of China
| | - Wafa Ali Eltayb
- 2School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027 People's Republic of China.,3Faculty of Science and Technology, Shendi University, Shendi, Nher Anile Sudan
| | - Aadil Yousif
- 4Faculty of Applied Medical Sciences, University of Tabuk, Tabuk, Saudi Arabia
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36
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The Gcn2-eIF2α pathway connects iron and amino acid homeostasis in Saccharomyces cerevisiae. Biochem J 2018; 475:1523-1534. [PMID: 29626156 DOI: 10.1042/bcj20170871] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 04/01/2018] [Accepted: 04/03/2018] [Indexed: 01/02/2023]
Abstract
In eukaryotic cells, amino acid biosynthesis is feedback-inhibited by amino acids through inhibition of the conserved protein kinase Gcn2. This decreases phosphorylation of initiation factor eIF2α, resulting in general activation of translation but inhibition of translation of mRNA for transcription factor (TF) Gcn4 in yeast or ATF4 in mammals. These TFs are positive regulators of amino acid biosynthetic genes. As several enzymes of amino acid biosynthesis contain iron-sulfur clusters (ISCs) and iron excess is toxic, iron and amino acid homeostasis should be co-ordinated. Working with the yeast Saccharomyces cerevisiae, we found that amino acid supplementation down-regulates expression of genes for iron uptake and decreases intracellular iron content. This cross-regulation requires Aft1, the major TF activated by iron scarcity, as well as Gcn2 and phosphorylatable eIF2α but not Gcn4. A mutant with constitutive activity of Gcn2 (GCN2c ) shows less repression of iron transport genes by amino acids and increased nuclear localization of Aft1 in an iron-poor medium, and increases iron content in this medium. As Aft1 is activated by depletion of mitochondrial ISCs, it is plausible that the Gcn2-eIF2α pathway inhibits the formation of these complexes. Accordingly, the GCN2c mutant has strongly reduced activity of succinate dehydrogenase, an iron-sulfur mitochondrial enzyme, and is unable to grow in media with very low iron or with galactose instead of glucose, conditions where formation of ISCs is specially needed. This mechanism adjusts the uptake of iron to the needs of amino acid biosynthesis and expands the list of Gcn4-independent activities of the Gcn2-eIF2α regulatory system.
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Tóth R, Cabral V, Thuer E, Bohner F, Németh T, Papp C, Nimrichter L, Molnár G, Vágvölgyi C, Gabaldón T, Nosanchuk JD, Gácser A. Investigation of Candida parapsilosis virulence regulatory factors during host-pathogen interaction. Sci Rep 2018; 8:1346. [PMID: 29358719 PMCID: PMC5777994 DOI: 10.1038/s41598-018-19453-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 01/02/2018] [Indexed: 01/23/2023] Open
Abstract
Invasive candidiasis is among the most life-threatening infections in patients in intensive care units. Although Candida albicans is the leading cause of candidaemia, the incidence of Candida parapsilosis infections is also rising, particularly among the neonates. Due to differences in their biology, these species employ different antifungal resistance and virulence mechanisms and also induce dissimilar immune responses. Previously, it has been suggested that core virulence effecting transcription regulators could be attractive ligands for future antifungal drugs. Although the virulence regulatory mechanisms of C. albicans are well studied, less is known about similar mechanisms in C. parapsilosis. In order to search for potential targets for future antifungal drugs against this species, we analyzed the fungal transcriptome during host-pathogen interaction using an in vitro infection model. Selected genes with high expression levels were further examined through their respective null mutant strains, under conditions that mimic the host environment or influence pathogenicity. As a result, we identified several mutants with relevant pathogenicity affecting phenotypes. During the study we highlight three potentially tractable signaling regulators that influence C. parapsilosis pathogenicity in distinct mechanisms. During infection, CPAR2_100540 is responsible for nutrient acquisition, CPAR2_200390 for cell wall assembly and morphology switching and CPAR2_303700 for fungal viability.
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Affiliation(s)
- Renáta Tóth
- Department of Microbiology, University of Szeged, Szeged, Hungary
| | - Vitor Cabral
- Departments of Medicine and Microbiology and Immunology, Albert Einstein College of Medicine, New York, NY, USA
| | - Ernst Thuer
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology, Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Flóra Bohner
- Department of Microbiology, University of Szeged, Szeged, Hungary
| | - Tibor Németh
- Department of Microbiology, University of Szeged, Szeged, Hungary
| | - Csaba Papp
- Department of Microbiology, University of Szeged, Szeged, Hungary
| | - Leonardo Nimrichter
- Laboratório de Glicobiologia de Eucariotos, Instituto de Microbiologia Professor Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Gergő Molnár
- Department of Microbiology, University of Szeged, Szeged, Hungary
| | - Csaba Vágvölgyi
- Department of Microbiology, University of Szeged, Szeged, Hungary
| | - Toni Gabaldón
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology, Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Joshua D Nosanchuk
- Departments of Medicine and Microbiology and Immunology, Albert Einstein College of Medicine, New York, NY, USA
| | - Attila Gácser
- Department of Microbiology, University of Szeged, Szeged, Hungary.
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38
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Hantzis LJ, Kroh GE, Jahn CE, Cantrell M, Peers G, Pilon M, Ravet K. A Program for Iron Economy during Deficiency Targets Specific Fe Proteins. PLANT PHYSIOLOGY 2018; 176:596-610. [PMID: 29150559 DOI: 10.1104/pp1701497] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 11/15/2017] [Indexed: 05/22/2023]
Abstract
Iron (Fe) is an essential element for plants, utilized in nearly every cellular process. Because the adjustment of uptake under Fe limitation cannot satisfy all demands, plants need to acclimate their physiology and biochemistry, especially in their chloroplasts, which have a high demand for Fe. To investigate if a program exists for the utilization of Fe under deficiency, we analyzed how hydroponically grown Arabidopsis (Arabidopsis thaliana) adjusts its physiology and Fe protein composition in vegetative photosynthetic tissue during Fe deficiency. Fe deficiency first affected photosynthetic electron transport with concomitant reductions in carbon assimilation and biomass production when effects on respiration were not yet significant. Photosynthetic electron transport function and protein levels of Fe-dependent enzymes were fully recovered upon Fe resupply, indicating that the Fe depletion stress did not cause irreversible secondary damage. At the protein level, ferredoxin, the cytochrome-b6f complex, and Fe-containing enzymes of the plastid sulfur assimilation pathway were major targets of Fe deficiency, whereas other Fe-dependent functions were relatively less affected. In coordination, SufA and SufB, two proteins of the plastid Fe-sulfur cofactor assembly pathway, were also diminished early by Fe depletion. Iron depletion reduced mRNA levels for the majority of the affected proteins, indicating that loss of enzyme was not just due to lack of Fe cofactors. SufB and ferredoxin were early targets of transcript down-regulation. The data reveal a hierarchy for Fe utilization in photosynthetic tissue and indicate that a program is in place to acclimate to impending Fe deficiency.
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Affiliation(s)
- Laura J Hantzis
- Biology Department, Colorado State University, Fort Collins, Colorado 80523-1878
| | - Gretchen E Kroh
- Biology Department, Colorado State University, Fort Collins, Colorado 80523-1878
| | - Courtney E Jahn
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, Colorado 80523-1177
| | - Michael Cantrell
- Biology Department, Colorado State University, Fort Collins, Colorado 80523-1878
| | - Graham Peers
- Biology Department, Colorado State University, Fort Collins, Colorado 80523-1878
| | - Marinus Pilon
- Biology Department, Colorado State University, Fort Collins, Colorado 80523-1878
| | - Karl Ravet
- Biology Department, Colorado State University, Fort Collins, Colorado 80523-1878
- INRA, Institut de Biologie Intégrative des Plantes, 34060 Montpellier, France
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39
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Hantzis LJ, Kroh GE, Jahn CE, Cantrell M, Peers G, Pilon M, Ravet K. A Program for Iron Economy during Deficiency Targets Specific Fe Proteins. PLANT PHYSIOLOGY 2018; 176:596-610. [PMID: 29150559 PMCID: PMC5761800 DOI: 10.1104/pp.17.01497] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 11/15/2017] [Indexed: 05/04/2023]
Abstract
Iron (Fe) is an essential element for plants, utilized in nearly every cellular process. Because the adjustment of uptake under Fe limitation cannot satisfy all demands, plants need to acclimate their physiology and biochemistry, especially in their chloroplasts, which have a high demand for Fe. To investigate if a program exists for the utilization of Fe under deficiency, we analyzed how hydroponically grown Arabidopsis (Arabidopsis thaliana) adjusts its physiology and Fe protein composition in vegetative photosynthetic tissue during Fe deficiency. Fe deficiency first affected photosynthetic electron transport with concomitant reductions in carbon assimilation and biomass production when effects on respiration were not yet significant. Photosynthetic electron transport function and protein levels of Fe-dependent enzymes were fully recovered upon Fe resupply, indicating that the Fe depletion stress did not cause irreversible secondary damage. At the protein level, ferredoxin, the cytochrome-b6f complex, and Fe-containing enzymes of the plastid sulfur assimilation pathway were major targets of Fe deficiency, whereas other Fe-dependent functions were relatively less affected. In coordination, SufA and SufB, two proteins of the plastid Fe-sulfur cofactor assembly pathway, were also diminished early by Fe depletion. Iron depletion reduced mRNA levels for the majority of the affected proteins, indicating that loss of enzyme was not just due to lack of Fe cofactors. SufB and ferredoxin were early targets of transcript down-regulation. The data reveal a hierarchy for Fe utilization in photosynthetic tissue and indicate that a program is in place to acclimate to impending Fe deficiency.
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Affiliation(s)
- Laura J Hantzis
- Biology Department, Colorado State University, Fort Collins, Colorado 80523-1878
| | - Gretchen E Kroh
- Biology Department, Colorado State University, Fort Collins, Colorado 80523-1878
| | - Courtney E Jahn
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, Colorado 80523-1177
| | - Michael Cantrell
- Biology Department, Colorado State University, Fort Collins, Colorado 80523-1878
| | - Graham Peers
- Biology Department, Colorado State University, Fort Collins, Colorado 80523-1878
| | - Marinus Pilon
- Biology Department, Colorado State University, Fort Collins, Colorado 80523-1878
| | - Karl Ravet
- Biology Department, Colorado State University, Fort Collins, Colorado 80523-1878
- INRA, Institut de Biologie Intégrative des Plantes, 34060 Montpellier, France
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40
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Li L, Ward DM. Iron toxicity in yeast: transcriptional regulation of the vacuolar iron importer Ccc1. Curr Genet 2017; 64:413-416. [PMID: 29043483 DOI: 10.1007/s00294-017-0767-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 10/11/2017] [Accepted: 10/13/2017] [Indexed: 11/27/2022]
Abstract
All eukaryotes require the transition metal, iron, a redox active element that is an essential cofactor in many metabolic pathways, as well as an oxygen carrier. Iron can also react to generate oxygen radicals such as hydroxyl radicals and superoxide anions, which are highly toxic to cells. Therefore, organisms have developed intricate mechanisms to acquire iron as well as to protect themselves from the toxic effects of excess iron. In fungi and plants, iron is stored in the vacuole as a protective mechanism against iron toxicity. Iron storage in the vacuole is mediated predominantly by the vacuolar metal importer Ccc1 in yeast and the homologous transporter VIT1 in plants. Transcription of yeast CCC1 expression is tightly controlled primarily by the transcription factor Yap5, which sits on the CCC1 promoter and activates transcription through the binding of Fe-S clusters. A second mechanism that regulates CCC1 transcription is through the Snf1 signaling pathway involved in low-glucose sensing. Snf1 activates stress transcription factors Msn2 and Msn4 to mediate CCC1 transcription. Transcriptional regulation by Yap5 and Snf1 are completely independent and provide for a graded response in Ccc1 expression. The identification of multiple independent transcriptional pathways that regulate the levels of Ccc1 under high iron conditions accentuates the importance of protecting cells from the toxic effects of high iron.
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Affiliation(s)
- Liangtao Li
- Division of Microbiology and Immunology, Department of Pathology, School of Medicine, University of Utah, Salt Lake City, UT, 84132-2501, USA
| | - Diane M Ward
- Division of Microbiology and Immunology, Department of Pathology, School of Medicine, University of Utah, Salt Lake City, UT, 84132-2501, USA.
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41
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Hirai K, Inukai T, Nakayama H. Promising Therapies for Fungal Infection Based on the Study to Elucidate Mechanisms to Cope with Stress in Candida Species [Translated Article]. Med Mycol J 2017. [PMID: 28566663 DOI: 10.3314/mmj.17.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
In recent years, the incidence of fungal infections has been increasing, particularly among patients with immune systems compromised by human immunodeficiency virus infection, organ transplantation, and/or chemotherapy for cancer. Current therapies for treating systemic fungal infection have limited effectiveness and have created problems of adverse reactions and drug resistance. These issues therefore motivate us to develop novel antifungals. Elucidation of stress response mechanisms and virulence factors in pathogenic fungi is required in developing an effective antifungal strategy. There are actually numerous studies concerning various stress responses in several important fungal pathogens. Among these responses, we focused on stress response for iron starvation to identify potential targets for novel antifungals because iron starvation occurs in blood, where pathogenic fungi often infect. Here we show recent progress of studies on iron homeostasis in Candida species, especially focusing on Candida glabrata, and propose novel antifungal targets.
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Affiliation(s)
- Kazuyuki Hirai
- Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science
| | - Tatsuya Inukai
- Department of Chemotherapy and Mycoses, National Institute of Infectious Diseases.,Diseases Division of Pathology, Immunology and Microbiology, Graduate School of Medicine, The University of Tokyo
| | - Hironobu Nakayama
- Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science
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42
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The CCAAT-Binding Complex Controls Respiratory Gene Expression and Iron Homeostasis in Candida Glabrata. Sci Rep 2017; 7:3531. [PMID: 28615656 PMCID: PMC5471220 DOI: 10.1038/s41598-017-03750-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 04/20/2017] [Indexed: 12/04/2022] Open
Abstract
The CCAAT-binding complex (CBC) is a heterotrimeric transcription factor which is widely conserved in eukaryotes. In the model yeast S. cerevisiae, CBC positively controls the expression of respiratory pathway genes. This role involves interactions with the regulatory subunit Hap4. In many pathogenic fungi, CBC interacts with the HapX regulatory subunit to control iron homeostasis. HapX is a bZIP protein which only shares with Hap4 the Hap4Like domain (Hap4L) required for its interaction with CBC. Here, we show that CBC has a dual role in the pathogenic yeast C. glabrata. It is required, along with Hap4, for the constitutive expression of respiratory genes and it is also essential for the iron stress response, which is mediated by the Yap5 bZIP transcription factor. Interestingly, Yap5 contains a vestigial Hap4L domain. The mutagenesis of this domain severely reduced Yap5 binding to its targets and compromised its interaction with Hap5. Hence, Yap5, like HapX in other species, acts as a CBC regulatory subunit in the regulation of iron stress response. This work reveals new aspects of iron homeostasis in C. glabrata and of the evolution of the role of CBC and Hap4L-bZIP proteins in this process.
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43
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Mourer T, Normant V, Labbé S. Heme Assimilation in Schizosaccharomyces pombe Requires Cell-surface-anchored Protein Shu1 and Vacuolar Transporter Abc3. J Biol Chem 2017; 292:4898-4912. [PMID: 28193844 DOI: 10.1074/jbc.m117.776807] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 02/08/2017] [Indexed: 12/12/2022] Open
Abstract
The Schizosaccharomyces pombe shu1+ gene encodes a cell-surface protein required for assimilation of exogenous heme. In this study, shaving experiments showed that Shu1 is released from membrane preparations when spheroplast lysates are incubated with phosphoinositide-specific phospholipase C (PI-PLC). Shu1 cleavability by PI-PLC and its predicted hydropathy profile strongly suggested that Shu1 is a glycosylphosphatidylinositol-anchored protein. When heme biosynthesis is selectively blocked in hem1Δ mutant cells, the heme analog zinc mesoporphyrin IX (ZnMP) first accumulates into vacuoles and then subsequently, within the cytoplasm in a rapid and Shu1-dependent manner. An HA4-tagged shu1+ allele that retained wild-type function localizes to the cell surface in response to low hemin concentrations, but under high hemin concentrations, Shu1-HA4 re-localizes to the vacuolar membrane. Inactivation of abc3+, encoding a vacuolar membrane transporter, results in hem1Δ abc3Δ mutant cells being unable to grow in the presence of hemin as the sole iron source. In hem1Δ abc3Δ cells, ZnMP accumulates primarily in vacuoles and does not sequentially accumulate in the cytosol. Consistent with a role for Abc3 as vacuolar hemin exporter, results with hemin-agarose pulldown assays showed that Abc3 binds to hemin. In contrast, an Abc3 mutant in which an inverted Cys-Pro motif had been replaced with Ala residues fails to bind hemin with high affinity. Taken together, these results show that Shu1 undergoes rapid hemin-induced internalization from the cell surface to the vacuolar membrane and that the transporter Abc3 participates in the mobilization of stored heme from the vacuole to the cytosol.
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Affiliation(s)
- Thierry Mourer
- From the Département de Biochimie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Quebec J1E 4K8, Canada
| | - Vincent Normant
- From the Département de Biochimie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Quebec J1E 4K8, Canada
| | - Simon Labbé
- From the Département de Biochimie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Quebec J1E 4K8, Canada
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44
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Mechanisms of iron sensing and regulation in the yeast Saccharomyces cerevisiae. World J Microbiol Biotechnol 2017; 33:75. [DOI: 10.1007/s11274-017-2215-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 01/18/2017] [Indexed: 01/11/2023]
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45
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Hebecker B, Vlaic S, Conrad T, Bauer M, Brunke S, Kapitan M, Linde J, Hube B, Jacobsen ID. Dual-species transcriptional profiling during systemic candidiasis reveals organ-specific host-pathogen interactions. Sci Rep 2016; 6:36055. [PMID: 27808111 PMCID: PMC5093689 DOI: 10.1038/srep36055] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 10/11/2016] [Indexed: 11/15/2022] Open
Abstract
Candida albicans is a common cause of life-threatening fungal bloodstream infections. In the murine model of systemic candidiasis, the kidney is the primary target organ while the fungal load declines over time in liver and spleen. To better understand these organ-specific differences in host-pathogen interaction, we performed gene expression profiling of murine kidney, liver and spleen and determined the fungal transcriptome in liver and kidney. We observed a delayed transcriptional immune response accompanied by late induction of fungal stress response genes in the kidneys. In contrast, early upregulation of the proinflammatory response in the liver was associated with a fungal transcriptome resembling response to phagocytosis, suggesting that phagocytes contribute significantly to fungal control in the liver. Notably, C. albicans hypha-associated genes were upregulated in the absence of visible filamentation in the liver, indicating an uncoupling of gene expression and morphology and a morphology-independent effect by hypha-associated genes in this organ. Consistently, integration of host and pathogen transcriptional data in an inter-species gene regulatory network indicated connections of C. albicans cell wall remodelling and metabolism to the organ-specific immune responses.
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Affiliation(s)
- Betty Hebecker
- Research Group Microbial Immunology, Leibniz Institute for Natural Product Research and Infection Biology (Hans Knöll Institute), Jena, Germany.,Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany
| | - Sebastian Vlaic
- Department of General, Visceral and Vascular Surgery, Experimental Transplantation Surgery, Jena University Hospital, Jena, Germany.,Research Group Systems Biology/Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology (Hans Knöll Institute), Jena, Germany.,Department of Bioinformatics, Friedrich-Schiller-University Jena, Germany
| | - Theresia Conrad
- Research Group Systems Biology/Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology (Hans Knöll Institute), Jena, Germany
| | - Michael Bauer
- Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany.,Department of Anaesthesiology and Intensive Care Therapy, Jena University Hospital, Jena, Germany
| | - Sascha Brunke
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology (Hans Knöll Institute), Jena, Germany
| | - Mario Kapitan
- Research Group Microbial Immunology, Leibniz Institute for Natural Product Research and Infection Biology (Hans Knöll Institute), Jena, Germany
| | - Jörg Linde
- Research Group Systems Biology/Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology (Hans Knöll Institute), Jena, Germany
| | - Bernhard Hube
- Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany.,Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology (Hans Knöll Institute), Jena, Germany.,Friedrich-Schiller-University, Jena, Germany
| | - Ilse D Jacobsen
- Research Group Microbial Immunology, Leibniz Institute for Natural Product Research and Infection Biology (Hans Knöll Institute), Jena, Germany.,Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany.,Friedrich-Schiller-University, Jena, Germany
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46
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Eisenberg-Bord M, Schuldiner M. Ground control to major TOM: mitochondria-nucleus communication. FEBS J 2016; 284:196-210. [PMID: 27283924 DOI: 10.1111/febs.13778] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Revised: 05/23/2016] [Accepted: 06/08/2016] [Indexed: 01/13/2023]
Abstract
Mitochondria have crucial functions in the cell, including ATP generation, iron-sulfur cluster biogenesis, nucleotide biosynthesis, and amino acid metabolism. All of these functions require tight regulation on mitochondrial activity and homeostasis. As mitochondria biogenesis is controlled by the nucleus and almost all mitochondrial proteins are encoded by nuclear genes, a tight communication network between mitochondria and the nucleus has evolved, which includes signaling cascades, proteins which are dual-localized to the two compartments, and sensing of mitochondrial products by nuclear proteins. All of these enable a crosstalk between mitochondria and the nucleus that allows the 'ground control' to get information on mitochondria's status. Such information facilitates the creation of a cellular balance of mitochondrial status with energetic needs. This communication also allows a transcriptional response in case mitochondrial function is impaired aimed to restore mitochondrial homeostasis. As mitochondrial dysfunction is related to a growing number of genetic diseases as well as neurodegenerative conditions and aging, elucidating the mechanisms governing the mitochondrial/nuclear communication should progress a better understanding of mitochondrial dysfunctions.
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Affiliation(s)
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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47
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The lysine biosynthetic enzyme Lys4 influences iron metabolism, mitochondrial function and virulence in Cryptococcus neoformans. Biochem Biophys Res Commun 2016; 477:706-711. [PMID: 27353379 DOI: 10.1016/j.bbrc.2016.06.123] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 06/24/2016] [Indexed: 12/17/2022]
Abstract
The lysine biosynthesis pathway via α-aminoadipate in fungi is considered an attractive target for antifungal drugs due to its absence in mammalian hosts. The iron-sulfur cluster-containing enzyme homoaconitase converts homocitrate to homoisocitrate in the lysine biosynthetic pathway, and is encoded by LYS4 in the model yeast Saccharomyces cerevisiae. In this study, we identified the ortholog of LYS4 in the human fungal pathogen, Cryptococcus neoformans, and found that LYS4 expression is regulated by iron levels and by the iron-related transcription factors Hap3 and HapX. Deletion of the LYS4 gene resulted in lysine auxotrophy suggesting that Lys4 is essential for lysine biosynthesis. Our study also revealed that lysine uptake was mediated by two amino acid permeases, Aap2 and Aap3, and influenced by nitrogen catabolite repression (NCR). Furthermore, the lys4 mutant showed increased sensitivity to oxidative stress, agents that challenge cell wall/membrane integrity, and azole antifungal drugs. We showed that these phenotypes were due in part to impaired mitochondrial function as a result of LYS4 deletion, which we propose disrupts iron homeostasis in the organelle. The combination of defects are consistent with our observation that the lys4 mutant was attenuated virulence in a mouse inhalation model of cryptococcosis.
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48
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de Llanos R, Martínez-Garay CA, Fita-Torró J, Romero AM, Martínez-Pastor MT, Puig S. Soybean Ferritin Expression in Saccharomyces cerevisiae Modulates Iron Accumulation and Resistance to Elevated Iron Concentrations. Appl Environ Microbiol 2016; 82:3052-3060. [PMID: 26969708 PMCID: PMC4959083 DOI: 10.1128/aem.00305-16] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 03/08/2016] [Indexed: 02/06/2023] Open
Abstract
UNLABELLED Fungi, including the yeast Saccharomyces cerevisiae, lack ferritin and use vacuoles as iron storage organelles. This work explored how plant ferritin expression influenced baker's yeast iron metabolism. Soybean seed ferritin H1 (SFerH1) and SFerH2 genes were cloned and expressed in yeast cells. Both soybean ferritins assembled as multimeric complexes, which bound yeast intracellular iron in vivo and, consequently, induced the activation of the genes expressed during iron scarcity. Soybean ferritin protected yeast cells that lacked the Ccc1 vacuolar iron detoxification transporter from toxic iron levels by reducing cellular oxidation, thus allowing growth at high iron concentrations. Interestingly, when simultaneously expressed in ccc1Δ cells, SFerH1 and SFerH2 assembled as heteropolymers, which further increased iron resistance and reduced the oxidative stress produced by excess iron compared to ferritin homopolymer complexes. Finally, soybean ferritin expression led to increased iron accumulation in both wild-type and ccc1Δ yeast cells at certain environmental iron concentrations. IMPORTANCE Iron deficiency is a worldwide nutritional disorder to which women and children are especially vulnerable. A common strategy to combat iron deficiency consists of dietary supplementation with inorganic iron salts, whose bioavailability is very low. Iron-enriched yeasts and cereals are alternative strategies to diminish iron deficiency. Animals and plants possess large ferritin complexes that accumulate, detoxify, or buffer excess cellular iron. However, the yeast Saccharomyces cerevisiae lacks ferritin and uses vacuoles as iron storage organelles. Here, we explored how soybean ferritin expression influenced yeast iron metabolism, confirming that yeasts that express soybean seed ferritin could be explored as a novel strategy to increase dietary iron absorption.
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Affiliation(s)
- Rosa de Llanos
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, Paterna, Valencia, Spain
| | - Carlos Andrés Martínez-Garay
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, Paterna, Valencia, Spain
| | - Josep Fita-Torró
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, Paterna, Valencia, Spain
| | - Antonia María Romero
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, Paterna, Valencia, Spain
| | | | - Sergi Puig
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, Paterna, Valencia, Spain
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Taymaz-Nikerel H, Cankorur-Cetinkaya A, Kirdar B. Genome-Wide Transcriptional Response of Saccharomyces cerevisiae to Stress-Induced Perturbations. Front Bioeng Biotechnol 2016; 4:17. [PMID: 26925399 PMCID: PMC4757645 DOI: 10.3389/fbioe.2016.00017] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 02/04/2016] [Indexed: 12/22/2022] Open
Abstract
Cells respond to environmental and/or genetic perturbations in order to survive and proliferate. Characterization of the changes after various stimuli at different -omics levels is crucial to comprehend the adaptation of cells to the changing conditions. Genome-wide quantification and analysis of transcript levels, the genes affected by perturbations, extends our understanding of cellular metabolism by pointing out the mechanisms that play role in sensing the stress caused by those perturbations and related signaling pathways, and in this way guides us to achieve endeavors, such as rational engineering of cells or interpretation of disease mechanisms. Saccharomyces cerevisiae as a model system has been studied in response to different perturbations and corresponding transcriptional profiles were followed either statically or/and dynamically, short and long term. This review focuses on response of yeast cells to diverse stress inducing perturbations, including nutritional changes, ionic stress, salt stress, oxidative stress, osmotic shock, and to genetic interventions such as deletion and overexpression of genes. It is aimed to conclude on common regulatory phenomena that allow yeast to organize its transcriptomic response after any perturbation under different external conditions.
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Affiliation(s)
| | | | - Betul Kirdar
- Department of Chemical Engineering, Bogazici University , Istanbul , Turkey
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Responses of Saccharomyces cerevisiae Strains from Different Origins to Elevated Iron Concentrations. Appl Environ Microbiol 2016; 82:1906-1916. [PMID: 26773083 DOI: 10.1128/aem.03464-15] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 01/08/2016] [Indexed: 01/10/2023] Open
Abstract
Iron is an essential micronutrient for all eukaryotic organisms. However, the low solubility of ferric iron has tremendously increased the prevalence of iron deficiency anemia, especially in women and children, with dramatic consequences. Baker's yeast Saccharomyces cerevisiae is used as a model eukaryotic organism, a fermentative microorganism, and a feed supplement. In this report, we explore the genetic diversity of 123 wild and domestic strains of S. cerevisiae isolated from different geographical origins and sources to characterize how yeast cells respond to elevated iron concentrations in the environment. By using two different forms of iron, we selected and characterized both iron-sensitive and iron-resistant yeast strains. We observed that when the iron concentration in the medium increases, iron-sensitive strains accumulate iron more rapidly than iron-resistant isolates. We observed that, consistent with excess iron leading to oxidative stress, the redox state of iron-sensitive strains was more oxidized than that of iron-resistant strains. Growth assays in the presence of different oxidative reagents ruled out that this phenotype was due to alterations in the general oxidative stress protection machinery. It was noteworthy that iron-resistant strains were more sensitive to iron deficiency conditions than iron-sensitive strains, which suggests that adaptation to either high or low iron is detrimental for the opposite condition. An initial gene expression analysis suggested that alterations in iron homeostasis genes could contribute to the different responses of distant iron-sensitive and iron-resistant yeast strains to elevated environmental iron levels.
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