1
|
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.
Collapse
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
| |
Collapse
|
2
|
Wang X, Zhou L, Dong Z, Wang G. Identification of iron metabolism-related predictive markers of endometriosis and endometriosis-relevant ovarian cancer. Medicine (Baltimore) 2023; 102:e33478. [PMID: 37058039 PMCID: PMC10101319 DOI: 10.1097/md.0000000000033478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 03/17/2023] [Indexed: 04/15/2023] Open
Abstract
Endometriosis is associated with ovarian cancers, mainly endometrioid and clear-cell carcinomas. Iron metabolism has been shown to play a role in endometriosis. Therefore, it is vital to explore the relationship between iron metabolism and ovarian cancer and to identify novel markers for diagnostics and therapeutics. The endometriosis dataset GSE51981 and the ovarian cancer dataset GSE26712 were obtained from the gene expression omnibus database, and differentially expressed genes were identified. Iron metabolism genes were obtained from molecular signatures database, and hub genes from the 3 datasets were obtained. Seven hub genes were identified by bioinformatic analysis, and 3 hub genes (NCOA4, ETFDH, and TYW1) were further selected by logistic regression, which were verified in an independent endometriosis dataset (GSE25628) and ovarian cancer dataset (GSE14407), showing good predictive diagnostic value (area under the receiver operating characteristic curve of 0.88 and 0.9, respectively). Gene Ontology, gene set enrichment analysis, and immune infiltration analysis further confirmed the related functions, pathways, and immune relationship between iron metabolism and ovarian cancer. This study highlights the potential of targeting iron metabolism in the prevention of potential ovarian cancer and in the further exploration of endometriosis and endometriosis-relevant ovarian cancer therapeutics.
Collapse
Affiliation(s)
- Xu Wang
- School of Clinical Medicine, Dali University, Dali, Yunnan Province, China
| | - Lixiang Zhou
- School of Clinical Medicine, Dali University, Dali, Yunnan Province, China
| | - Zhaomei Dong
- Department of Reproductive Medicine, The First Affiliated Hospital of Dali University, Dali, Yunnan Province, China
| | - Guangming Wang
- School of Clinical Medicine, Dali University, Dali, Yunnan Province, China
- Center of Genetic Testing, The First Affiliated Hospital of Dali University, Dali, Yunnan Province, China
| |
Collapse
|
3
|
Yukawa T, Bamba T, Matsuda M, Yoshida T, Inokuma K, Kim J, Won Lee J, Jin YS, Kondo A, Hasunuma T. Enhanced production of 3,4-dihydroxybutyrate from xylose by engineered yeast via xylonate re-assimilation under alkaline condition. Biotechnol Bioeng 2023; 120:511-523. [PMID: 36321324 DOI: 10.1002/bit.28278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 09/27/2022] [Accepted: 10/28/2022] [Indexed: 11/07/2022]
Abstract
To realize lignocellulose-based bioeconomy, efficient conversion of xylose into valuable chemicals by microbes is necessary. Xylose oxidative pathways that oxidize xylose into xylonate can be more advantageous than conventional xylose assimilation pathways because of fewer reaction steps without loss of carbon and ATP. Moreover, commodity chemicals like 3,4-dihydroxybutyrate and 3-hydroxybutyrolactone can be produced from the intermediates of xylose oxidative pathway. However, successful implementations of xylose oxidative pathway in yeast have been hindered because of the secretion and accumulation of xylonate which is a key intermediate of the pathway, leading to low yield of target product. Here, high-yield production of 3,4-dihydroxybutyrate from xylose by engineered yeast was achieved through genetic and environmental perturbations. Specifically, 3,4-dihydroxybutyrate biosynthetic pathway was established in yeast through deletion of ADH6 and overexpression of yneI. Also, inspired by the mismatch of pH between host strain and key enzyme of XylD, alkaline fermentations (pH ≥ 7.0) were performed to minimize xylonate accumulation. Under the alkaline conditions, xylonate was re-assimilated by engineered yeast and combined product yields of 3,4-dihydroxybutyrate and 3-hydroxybutyrolactone resulted in 0.791 mol/mol-xylose, which is highest compared with previous study. These results shed light on the utility of the xylose oxidative pathway in yeast.
Collapse
Affiliation(s)
- Takahiro Yukawa
- Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan
| | - Takahiro Bamba
- Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan
| | - Mami Matsuda
- Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan.,Engineering Biology Research Center, Kobe University, Kobe, Japan
| | - Takanobu Yoshida
- Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan
| | - Kentaro Inokuma
- Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan
| | - Jungyeon Kim
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Jae Won Lee
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Yong-Su Jin
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Akihiko Kondo
- Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan.,Engineering Biology Research Center, Kobe University, Kobe, Japan.,RIKEN Center for Sustainable Resource Science, Kanagawa, Japan
| | - Tomohisa Hasunuma
- Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan.,Engineering Biology Research Center, Kobe University, Kobe, Japan.,RIKEN Center for Sustainable Resource Science, Kanagawa, Japan
| |
Collapse
|
4
|
The polyHIS Tract of Yeast AMPK Coordinates Carbon Metabolism with Iron Availability. Int J Mol Sci 2023; 24:ijms24021368. [PMID: 36674878 PMCID: PMC9863760 DOI: 10.3390/ijms24021368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/06/2023] [Accepted: 01/07/2023] [Indexed: 01/13/2023] Open
Abstract
Energy status in all eukaryotic cells is sensed by AMP-kinases. We have previously found that the poly-histidine tract at the N-terminus of S. cerevisiae AMPK (Snf1) inhibits its function in the presence of glucose via a pH-regulated mechanism. We show here that in the absence of glucose, the poly-histidine tract has a second function, linking together carbon and iron metabolism. Under conditions of iron deprivation, when different iron-intense cellular systems compete for this scarce resource, Snf1 is inhibited. The inhibition is via an interaction of the poly-histidine tract with the low-iron transcription factor Aft1. Aft1 inhibition of Snf1 occurs in the nucleus at the nuclear membrane, and only inhibits nuclear Snf1, without affecting cytosolic Snf1 activities. Thus, the temporal and spatial regulation of Snf1 activity enables a differential response to iron depending upon the type of carbon source. The linkage of nuclear Snf1 activity to iron sufficiency ensures that sufficient clusters are available to support respiratory enzymatic activity and tests mitochondrial competency prior to activation of nuclear Snf1.
Collapse
|
5
|
Sorribes-Dauden R, Jordá T, Peris D, Martínez-Pastor MT, Puig S. Adaptation of Saccharomyces Species to High-Iron Conditions. Int J Mol Sci 2022; 23:13965. [PMID: 36430442 PMCID: PMC9693265 DOI: 10.3390/ijms232213965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/06/2022] [Accepted: 11/09/2022] [Indexed: 11/16/2022] Open
Abstract
Iron is an indispensable element that participates as an essential cofactor in multiple biological processes. However, when present in excess, iron can engage in redox reactions that generate reactive oxygen species that damage cells at multiple levels. In this report, we characterized the response of budding yeast species from the Saccharomyces genus to elevated environmental iron concentrations. We have observed that S. cerevisiae strains are more resistant to high-iron concentrations than Saccharomyces non-cerevisiae species. Liquid growth assays showed that species evolutionarily closer to S. cerevisiae, such as S. paradoxus, S. jurei, S. mikatae, and S. arboricola, were more resistant to high-iron levels than the more distant species S. eubayanus and S. uvarum. Remarkably, S. kudriavzevii strains were especially iron sensitive. Growth assays in solid media suggested that S. cerevisiae and S. paradoxus were more resistant to the oxidative stress caused by elevated iron concentrations. When comparing iron accumulation and sensitivity, different patterns were observed. As previously described for S. cerevisiae, S. uvarum and particular strains of S. kudriavzevii and S. paradoxus became more sensitive to iron while accumulating more intracellular iron levels. However, no remarkable changes in intracellular iron accumulation were observed for the remainder of species. These results indicate that different mechanisms of response to elevated iron concentrations exist in the different species of the genus Saccharomyces.
Collapse
Affiliation(s)
- Raquel Sorribes-Dauden
- Departamento de Bioquímica y Biología Molecular, Universitat de València, Doctor Moliner 50, 46100 Burjassot, Spain
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Agustín Escardino 7, 46980 Paterna, Spain
| | - Tania Jordá
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Agustín Escardino 7, 46980 Paterna, Spain
| | - David Peris
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Agustín Escardino 7, 46980 Paterna, Spain
- Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, Blindernveien 31, 0371 Oslo, Norway
| | - María Teresa Martínez-Pastor
- Departamento de Bioquímica y Biología Molecular, Universitat de València, Doctor Moliner 50, 46100 Burjassot, Spain
| | - Sergi Puig
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Agustín Escardino 7, 46980 Paterna, Spain
| |
Collapse
|
6
|
Lindahl PA, Vali SW. Mössbauer-based molecular-level decomposition of the Saccharomyces cerevisiae ironome, and preliminary characterization of isolated nuclei. Metallomics 2022; 14:mfac080. [PMID: 36214417 PMCID: PMC9624242 DOI: 10.1093/mtomcs/mfac080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 09/23/2022] [Indexed: 11/25/2022]
Abstract
One hundred proteins in Saccharomyces cerevisiae are known to contain iron. These proteins are found mainly in mitochondria, cytosol, nuclei, endoplasmic reticula, and vacuoles. Cells also contain non-proteinaceous low-molecular-mass labile iron pools (LFePs). How each molecular iron species interacts on the cellular or systems' level is underdeveloped as doing so would require considering the entire iron content of the cell-the ironome. In this paper, Mössbauer (MB) spectroscopy was used to probe the ironome of yeast. MB spectra of whole cells and isolated organelles were predicted by summing the spectral contribution of each iron-containing species in the cell. Simulations required input from published proteomics and microscopy data, as well as from previous spectroscopic and redox characterization of individual iron-containing proteins. Composite simulations were compared to experimentally determined spectra. Simulated MB spectra of non-proteinaceous iron pools in the cell were assumed to account for major differences between simulated and experimental spectra of whole cells and isolated mitochondria and vacuoles. Nuclei were predicted to contain ∼30 μM iron, mostly in the form of [Fe4S4] clusters. This was experimentally confirmed by isolating nuclei from 57Fe-enriched cells and obtaining the first MB spectra of the organelle. This study provides the first semi-quantitative estimate of all concentrations of iron-containing proteins and non-proteinaceous species in yeast, as well as a novel approach to spectroscopically characterizing LFePs.
Collapse
Affiliation(s)
- Paul A Lindahl
- Department of Chemistry, Texas A&M University, College Station, TX,USA
- Department of Biochemistry and Biophysics, Texas A&M University, College Station TX,USA
| | - Shaik Waseem Vali
- Department of Chemistry, Texas A&M University, College Station, TX,USA
| |
Collapse
|
7
|
Delaveau T, Thiébaut A, Benchouaia M, Merhej J, Devaux F. Yap5 Competes With Hap4 for the Regulation of Iron Homeostasis Genes in the Human Pathogen Candida glabrata. Front Cell Infect Microbiol 2021; 11:731988. [PMID: 34900750 PMCID: PMC8662346 DOI: 10.3389/fcimb.2021.731988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 11/10/2021] [Indexed: 11/18/2022] Open
Abstract
The CCAAT-binding complex (CBC) is a conserved heterotrimeric transcription factor which, in fungi, requires additional regulatory subunits to act on transcription. In the pathogenic yeast Candida glabrata, CBC has a dual role. Together with the Hap4 regulatory subunit, it activates the expression of genes involved in respiration upon growth with non-fermentable carbon sources, while its association with the Yap5 regulatory subunit is required for the activation of iron tolerance genes in response to iron excess. In the present work, we investigated further the interplay between CBC, Hap4 and Yap5. We showed that Yap5 regulation requires a specific Yap Response Element in the promoter of its target gene GRX4 and that the presence of Yap5 considerably strengthens the binding of CBC to the promoters of iron tolerance genes. Chromatin immunoprecipitation (ChIP) and transcriptome experiments showed that Hap4 can also bind these promoters but has no impact on the expression of those genes when Yap5 is present. In the absence of Yap5 however, GRX4 is constitutively regulated by Hap4, similarly to the genes involved in respiration. Our results suggest that the distinction between the two types of CBC targets in C. glabrata is mainly due to the dependency of Yap5 for very specific DNA sequences and to the competition between Hap4 and Yap5 at the promoter of the iron tolerance genes.
Collapse
Affiliation(s)
- Thierry Delaveau
- Sorbonne Université, CNRS, Institut de biologie Paris-Seine (IBPS), UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative, Paris, France
| | - Antonin Thiébaut
- Sorbonne Université, CNRS, Institut de biologie Paris-Seine (IBPS), UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative, Paris, France
| | - Médine Benchouaia
- Sorbonne Université, CNRS, Institut de biologie Paris-Seine (IBPS), UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative, Paris, France
| | - Jawad Merhej
- Sorbonne Université, CNRS, Institut de biologie Paris-Seine (IBPS), UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative, Paris, France
| | - Frédéric Devaux
- Sorbonne Université, CNRS, Institut de biologie Paris-Seine (IBPS), UMR 7238, Laboratoire de Biologie Computationnelle et Quantitative, Paris, France
| |
Collapse
|
8
|
Palermo GCDL, Coutouné N, Bueno JGR, Maciel LF, dos Santos LV. Exploring metal ion metabolisms to improve xylose fermentation in Saccharomyces cerevisiae. Microb Biotechnol 2021; 14:2101-2115. [PMID: 34313008 PMCID: PMC8449651 DOI: 10.1111/1751-7915.13887] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/25/2021] [Indexed: 01/22/2023] Open
Abstract
The development of high-performance xylose-fermenting yeast is essential to achieve feasible conversion of biomass-derived sugars in lignocellulose-based biorefineries. However, engineered C5-strains of Saccharomyces cerevisiae still present low xylose consumption rates under anaerobic conditions. Here, we explore alternative metabolisms involved in metal homeostasis, which positively affect C5 fermentation and analyse the non-obvious regulatory network connection of both metabolisms using time-course transcriptome analysis. Our results indicated the vacuolar Fe2+ /Mn2+ transporter CCC1, and the protein involved in heavy metal ion homeostasis BSD2, as promising new targets for rational metabolic engineering strategies, enhancing xylose consumption in nine and 2.3-fold compared with control. Notably, intracellular metal concentration levels were affected differently by mutations and the results were compared with positive controls isu1Δ, a Fe-S cluster scaffold protein, and ssk2Δ, a component of HOG pathway. Temporal expression profiles indicate a metabolic remodelling in response to xylose, demonstrating changes in the main sugar sensing signalling pathways.
Collapse
Affiliation(s)
- Gisele Cristina de Lima Palermo
- Brazilian Biorenewable National Laboratory (LNBR)Brazilian Center for Research in Energy and Materials (CNPEM)CampinasSão Paulo13083‐100Brazil
- Genetics and Molecular Biology Graduate ProgramInstitute of BiologyUniversity of Campinas (UNICAMP)CampinasSão PauloBrazil
| | - Natalia Coutouné
- Brazilian Biorenewable National Laboratory (LNBR)Brazilian Center for Research in Energy and Materials (CNPEM)CampinasSão Paulo13083‐100Brazil
- Genetics and Molecular Biology Graduate ProgramInstitute of BiologyUniversity of Campinas (UNICAMP)CampinasSão PauloBrazil
| | - João Gabriel Ribeiro Bueno
- Brazilian Biorenewable National Laboratory (LNBR)Brazilian Center for Research in Energy and Materials (CNPEM)CampinasSão Paulo13083‐100Brazil
- Genetics and Molecular Biology Graduate ProgramInstitute of BiologyUniversity of Campinas (UNICAMP)CampinasSão PauloBrazil
| | - Lucas Ferreira Maciel
- Brazilian Biorenewable National Laboratory (LNBR)Brazilian Center for Research in Energy and Materials (CNPEM)CampinasSão Paulo13083‐100Brazil
| | - Leandro Vieira dos Santos
- Brazilian Biorenewable National Laboratory (LNBR)Brazilian Center for Research in Energy and Materials (CNPEM)CampinasSão Paulo13083‐100Brazil
- Genetics and Molecular Biology Graduate ProgramInstitute of BiologyUniversity of Campinas (UNICAMP)CampinasSão PauloBrazil
| |
Collapse
|
9
|
Understanding D-xylonic acid accumulation: a cornerstone for better metabolic engineering approaches. Appl Microbiol Biotechnol 2021; 105:5309-5324. [PMID: 34215905 DOI: 10.1007/s00253-021-11410-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 06/08/2021] [Accepted: 06/10/2021] [Indexed: 01/02/2023]
Abstract
The xylose oxidative pathway (XOP) has been engineered in microorganisms for the production of a wide range of industrially relevant compounds. However, the performance of metabolically engineered XOP-utilizing microorganisms is typically hindered by D-xylonic acid accumulation. It acidifies the media and perturbs cell growth due to toxicity, thus curtailing enzymatic activity and target product formation. Fortunately, from the growing portfolio of genetic tools, several strategies that can be adapted for the generation of efficient microbial cell factories have been implemented to address D-xylonic acid accumulation. This review centers its discussion on the causes of D-xylonic acid accumulation and how to address it through different engineering and synthetic biology techniques with emphasis given on bacterial strains. In the first part of this review, the ability of certain microorganisms to produce and tolerate D-xylonic acid is also tackled as an important aspect in developing efficient microbial cell factories. Overall, this review could shed some insights and clarity to those working on XOP in bacteria and its engineering for the development of industrially applicable product-specialist strains. KEY POINTS: D-Xylonic acid accumulation is attributed to the overexpression of xylose dehydrogenase concomitant with basal or inefficient expression of enzymes involved in D-xylonic acid assimilation. Redox imbalance and insufficient cofactors contribute to D-xylonic acid accumulation. Overcoming D-xylonic acid accumulation can increase product formation among engineered strains. Engineering strategies involving enzyme engineering, evolutionary engineering, coutilization of different sugar substrates, and synergy of different pathways could potentially address D-xylonic acid accumulation.
Collapse
|
10
|
Iron in Translation: From the Beginning to the End. Microorganisms 2021; 9:microorganisms9051058. [PMID: 34068342 PMCID: PMC8153317 DOI: 10.3390/microorganisms9051058] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 05/10/2021] [Accepted: 05/11/2021] [Indexed: 12/16/2022] Open
Abstract
Iron is an essential element for all eukaryotes, since it acts as a cofactor for many enzymes involved in basic cellular functions, including translation. While the mammalian iron-regulatory protein/iron-responsive element (IRP/IRE) system arose as one of the first examples of translational regulation in higher eukaryotes, little is known about the contribution of iron itself to the different stages of eukaryotic translation. In the yeast Saccharomyces cerevisiae, iron deficiency provokes a global impairment of translation at the initiation step, which is mediated by the Gcn2-eIF2α pathway, while the post-transcriptional regulator Cth2 specifically represses the translation of a subgroup of iron-related transcripts. In addition, several steps of the translation process depend on iron-containing enzymes, including particular modifications of translation elongation factors and transfer RNAs (tRNAs), and translation termination by the ATP-binding cassette family member Rli1 (ABCE1 in humans) and the prolyl hydroxylase Tpa1. The influence of these modifications and their correlation with codon bias in the dynamic control of protein biosynthesis, mainly in response to stress, is emerging as an interesting focus of research. Taking S. cerevisiae as a model, we hereby discuss the relevance of iron in the control of global and specific translation steps.
Collapse
|
11
|
Bulk autophagy induction and life extension is achieved when iron is the only limited nutrient in Saccharomyces cerevisiae. Biochem J 2021; 478:811-837. [DOI: 10.1042/bcj20200849] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 01/26/2021] [Accepted: 01/27/2021] [Indexed: 01/21/2023]
Abstract
We have investigated the effects that iron limitation provokes in Saccharomyces cerevisiae exponential cultures. We have demonstrated that one primary response is the induction of bulk autophagy mediated by TORC1. Coherently, Atg13 became dephosphorylated whereas Atg1 appeared phosphorylated. The signal of iron deprivation requires Tor2/Ypk1 activity and the inactivation of Tor1 leading to Atg13 dephosphorylation, thus triggering the autophagy process. Iron replenishment in its turn, reduces autophagy flux through the AMPK Snf1 and the subsequent activity of the iron-responsive transcription factor, Aft1. This signalling converges in Atg13 phosphorylation mediated by Tor1. Iron limitation promotes accumulation of trehalose and the increase in stress resistance leading to a quiescent state in cells. All these effects contribute to the extension of the chronological life, in a manner totally dependent on autophagy activation.
Collapse
|
12
|
Biz A, Mahadevan R. Overcoming Challenges in Expressing Iron-Sulfur Enzymes in Yeast. Trends Biotechnol 2020; 39:665-677. [PMID: 33339619 DOI: 10.1016/j.tibtech.2020.11.005] [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: 07/16/2020] [Revised: 11/03/2020] [Accepted: 11/09/2020] [Indexed: 01/07/2023]
Abstract
Iron-sulfur clusters are metal cofactors that are present in all domains of life. Many enzymes that require these cofactors have biotechnological importance, because they can be used to uncover catabolic routes to new sugar substrates or can be a critical part of pathways to produce chemicals and biofuels. However, the expression of these iron-sulfur enzymes of bacterial origin in yeast at high levels is a significant bottleneck. Intermediates upstream of the enzyme accumulate, because the activity of these enzymes is either low or completely absent. In this review, we examine possible explanations for this limitation, discuss potential genetic interventions in the yeast host that can increase iron-sulfur enzyme activity, and suggest future directions for creating more efficient yeast hosts capable of high iron-sulfur enzyme expression.
Collapse
Affiliation(s)
- Alessandra Biz
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ONT, Canada
| | - Radhakrishnan Mahadevan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ONT, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ONT, Canada.
| |
Collapse
|
13
|
Sorribes-Dauden R, Peris D, Martínez-Pastor MT, Puig S. Structure and function of the vacuolar Ccc1/VIT1 family of iron transporters and its regulation in fungi. Comput Struct Biotechnol J 2020; 18:3712-3722. [PMID: 33304466 PMCID: PMC7714665 DOI: 10.1016/j.csbj.2020.10.044] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/28/2020] [Accepted: 10/31/2020] [Indexed: 02/06/2023] Open
Abstract
Iron is an essential micronutrient for most living beings since it participates as a redox active cofactor in many biological processes including cellular respiration, lipid biosynthesis, DNA replication and repair, and ribosome biogenesis and recycling. However, when present in excess, iron can participate in Fenton reactions and generate reactive oxygen species that damage cells at the level of proteins, lipids and nucleic acids. Organisms have developed different molecular strategies to protect themselves against the harmful effects of high concentrations of iron. In the case of fungi and plants, detoxification mainly occurs by importing cytosolic iron into the vacuole through the Ccc1/VIT1 iron transporter. New sequenced genomes and bioinformatic tools are facilitating the functional characterization, evolution and ecological relevance of metabolic pathways and homeostatic networks across the Tree of Life. Sequence analysis shows that Ccc1/VIT1 homologs are widely distributed among organisms with the exception of animals. The recent elucidation of the crystal structure of a Ccc1/VIT1 plant ortholog has enabled the identification of both conserved and species-specific motifs required for its metal transport mechanism. Moreover, recent studies in the yeast Saccharomyces cerevisiae have also revealed that multiple transcription factors including Yap5 and Msn2/Msn4 contribute to the expression of CCC1 in high-iron conditions. Interestingly, Malaysian S. cerevisiae strains express a partially functional Ccc1 protein that renders them sensitive to iron. Different regulatory mechanisms have been described for non-Saccharomycetaceae Ccc1 homologs. The characterization of Ccc1/VIT1 proteins is of high interest in the development of biofortified crops and the protection against microbial-derived diseases.
Collapse
Key Words
- BLOSUM, BLOcks SUbstitution Matrix
- CBC, CCAAT-binding core complex
- CRD, Cysteine-rich domain
- CS, Consistency score
- Ccc1
- Cg, Candida glabrata
- Eg, Eucalyptus grandis
- Fe, Iron
- Fungi
- H, Helix
- Hap, Heme activator protein
- ISC, Iron-sulfur luster
- Iron detoxification
- Iron regulation
- Iron transport
- MAFFT, Multiple Alignment using Fast Fourier Transform
- MBD, Metal-binding domain
- ML, Maximum-likelihood
- NRAMP, Natural Resistance-Associated Macrophage Protein
- Plants
- ROS, Reactive oxygen species
- TMD, Transmembrane domain
- VIT, Vacuolar iron transporter
- VIT1
- VTL, Vacuolar iron transporter-like
- Vacuole
- YRE, Yap response elements
- Yeast
- bZIP, basic leucine-zipper
Collapse
Affiliation(s)
- Raquel Sorribes-Dauden
- Departamento de Bioquímica y Biología Molecular, Universitat de València, Burjassot, Valencia, Spain
| | - David Peris
- 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
| |
Collapse
|
14
|
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.
Collapse
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
| |
Collapse
|
15
|
Gupta M, Outten CE. Iron-sulfur cluster signaling: The common thread in fungal iron regulation. Curr Opin Chem Biol 2020; 55:189-201. [PMID: 32234663 DOI: 10.1016/j.cbpa.2020.02.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 02/02/2020] [Accepted: 02/20/2020] [Indexed: 02/07/2023]
Abstract
Iron homeostasis in fungi involves balancing iron uptake and storage with iron utilization to achieve adequate, nontoxic levels of this essential nutrient. Extensive work in the nonpathogenic yeast Saccharomyces cerevisiae and Schizosaccharomyces pombe has uncovered unique iron regulation networks for each organism that control iron metabolism via distinct molecular mechanisms. However, common themes have emerged from these studies. The activities of all fungal iron-sensing transcription factors characterized to date are regulated via iron-sulfur cluster signaling. Furthermore, glutaredoxins often play a key role in relaying the intracellular iron status to these DNA-binding proteins. Recent work with fungal pathogens, including Candida and Aspergillus species and Cryptococcus neoformans, has revealed novel iron regulation mechanisms, yet similar roles for iron-sulfur clusters and glutaredoxins in iron signaling have been confirmed. This review will focus on these recent discoveries regarding iron regulation pathways in both pathogenic and nonpathogenic fungi.
Collapse
Affiliation(s)
- Malini Gupta
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA 29208
| | - Caryn E Outten
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA 29208.
| |
Collapse
|
16
|
Li L, Bertram S, Kaplan J, Jia X, Ward DM. The mitochondrial iron exporter genes MMT1 and MMT2 in yeast are transcriptionally regulated by Aft1 and Yap1. J Biol Chem 2020; 295:1716-1726. [PMID: 31896574 PMCID: PMC7008362 DOI: 10.1074/jbc.ra119.011154] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 12/30/2019] [Indexed: 12/12/2022] Open
Abstract
Budding yeast (Saccharomyces cerevisiae) responds to low cytosolic iron by up-regulating the expression of iron import genes; iron import can reflect iron transport into the cytosol or mitochondria. Mmt1 and Mmt2 are nuclearly encoded mitochondrial proteins that export iron from the mitochondria into the cytosol. Here we report that MMT1 and MMT2 expression is transcriptionally regulated by two pathways: the low-iron-sensing transcription factor Aft1 and the oxidant-sensing transcription factor Yap1. We determined that MMT1 and MMT2 expression is increased under low-iron conditions and decreased when mitochondrial iron import is increased through overexpression of the high-affinity mitochondrial iron importer Mrs3. Moreover, loss of iron-sulfur cluster synthesis induced expression of MMT1 and MMT2 We show that exposure to the oxidant H2O2 induced MMT1 expression but not MMT2 expression and identified the transcription factor Yap1 as being involved in oxidant-mediated MMT1 expression. We defined Aft1- and Yap1-dependent transcriptional sites in the MMT1 promoter that are necessary for low-iron- or oxidant-mediated MMT1 expression. We also found that the MMT2 promoter contains domains that are important for regulating its expression under low-iron conditions, including an upstream region that appears to partially repress expression under low-iron conditions. Our findings reveal that MMT1 and MMT2 are induced under low-iron conditions and that the low-iron regulator Aft1 is required for this induction. We further uncover an Aft1-binding site in the MMT1 promoter sufficient for inducing MMT1 transcription and identify an MMT2 promoter region required for low iron induction.
Collapse
Affiliation(s)
- Liangtao Li
- Department of Pathology, Division of Microbiology and Immunology, University of Utah School of Medicine, Salt Lake City, Utah 84132
| | - Sophie Bertram
- Department of Pathology, Division of Microbiology and Immunology, University of Utah School of Medicine, Salt Lake City, Utah 84132
| | - Jerry Kaplan
- Department of Pathology, Division of Microbiology and Immunology, University of Utah School of Medicine, Salt Lake City, Utah 84132
| | - Xuan Jia
- Department of Pathology, Division of Microbiology and Immunology, University of Utah School of Medicine, Salt Lake City, Utah 84132
| | - Diane M Ward
- Department of Pathology, Division of Microbiology and Immunology, University of Utah School of Medicine, Salt Lake City, Utah 84132.
| |
Collapse
|
17
|
Bamba T, Yukawa T, Guirimand G, Inokuma K, Sasaki K, Hasunuma T, Kondo A. Production of 1,2,4-butanetriol from xylose by Saccharomyces cerevisiae through Fe metabolic engineering. Metab Eng 2019; 56:17-27. [PMID: 31434008 DOI: 10.1016/j.ymben.2019.08.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 07/24/2019] [Accepted: 08/17/2019] [Indexed: 11/29/2022]
Abstract
1,2,4-Butanetriol can be used to produce energetic plasticizer as well as several pharmaceutical compounds. Although Saccharomyces cerevisiae has some attractive characters such as high robustness for industrial production of useful chemicals by fermentation, 1,2,4-butanetriol production by S. cerevisiae has not been reported. 1,2,4-butanteriotl is produced by an oxidative xylose metabolic pathway completely different from the xylose reductase-xylitol dehydrogenase and the xylose isomerase pathways conventionally used for xylose assimilation in S. cerevisiae. In the present study, S. cerevisiae was engineered to produce 1,2,4-butanetriol by overexpression of xylose dehydrogenase (XylB), xylonate dehydratase (XylD), and 2-ketoacid decarboxylase. Further improvement of the recombinant strain was performed by the screening of optimal 2-ketoacid decarboxylase suitable for 1,2,4-butanetriol production and the enhancement of Fe uptake ability to improve the XylD enzymatic activity. Eventually, 1.7 g/L of 1,2,4-butanetriol was produced from 10 g/L xylose with a molar yield of 24.5%. Furthermore, 1.1 g/L of 1,2,4-butanetriol was successfully produced by direct fermentation of rice straw hydrolysate.
Collapse
Affiliation(s)
- Takahiro Bamba
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
| | - Takahiro Yukawa
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
| | - Gregory Guirimand
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan; Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
| | - Kentaro Inokuma
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
| | - Kengo Sasaki
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan; Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
| | - Tomohisa Hasunuma
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan; Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
| | - Akihiko Kondo
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan; Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan; Biomass Engineering Program, RIKEN, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan.
| |
Collapse
|
18
|
Rodrigues-Pousada C, Devaux F, Caetano SM, Pimentel C, da Silva S, Cordeiro AC, Amaral C. Yeast AP-1 like transcription factors (Yap) and stress response: a current overview. MICROBIAL CELL 2019; 6:267-285. [PMID: 31172012 PMCID: PMC6545440 DOI: 10.15698/mic2019.06.679] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Yeast adaptation to stress has been extensively studied. It involves large reprogramming of genome expression operated by many, more or less specific, transcription factors. Here, we review our current knowledge on the function of the eight Yap transcription factors (Yap1 to Yap8) in Saccharomyces cerevisiae, which were shown to be involved in various stress responses. More precisely, Yap1 is activated under oxidative stress, Yap2/Cad1 under cadmium, Yap4/Cin5 and Yap6 under osmotic shock, Yap5 under iron overload and Yap8/Arr1 by arsenic compounds. Yap3 and Yap7 seem to be involved in hydroquinone and nitrosative stresses, respectively. The data presented in this article illustrate how much knowledge on the function of these Yap transcription factors is advanced. The evolution of the Yap family and its roles in various pathogenic and non-pathogenic fungal species is discussed in the last section.
Collapse
Affiliation(s)
- Claudina Rodrigues-Pousada
- Instituto de Tecnologia Química e Biológica Anónio Xavier, Universidade Nova de Lisboa, Avenida da República, EAN, Oeiras 2781-901, Oeiras, Portugal
| | - Frédéric Devaux
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, F-75005, Paris, France
| | - Soraia M Caetano
- Instituto de Tecnologia Química e Biológica Anónio Xavier, Universidade Nova de Lisboa, Avenida da República, EAN, Oeiras 2781-901, Oeiras, Portugal
| | - Catarina Pimentel
- Instituto de Tecnologia Química e Biológica Anónio Xavier, Universidade Nova de Lisboa, Avenida da República, EAN, Oeiras 2781-901, Oeiras, Portugal
| | - Sofia da Silva
- Instituto de Tecnologia Química e Biológica Anónio Xavier, Universidade Nova de Lisboa, Avenida da República, EAN, Oeiras 2781-901, Oeiras, Portugal
| | - Ana Carolina Cordeiro
- Instituto de Tecnologia Química e Biológica Anónio Xavier, Universidade Nova de Lisboa, Avenida da República, EAN, Oeiras 2781-901, Oeiras, Portugal
| | - Catarina Amaral
- Instituto de Tecnologia Química e Biológica Anónio Xavier, Universidade Nova de Lisboa, Avenida da República, EAN, Oeiras 2781-901, Oeiras, Portugal
| |
Collapse
|
19
|
Devaux F, Thiébaut A. The regulation of iron homeostasis in the fungal human pathogen Candida glabrata. MICROBIOLOGY-SGM 2019; 165:1041-1060. [PMID: 31050635 DOI: 10.1099/mic.0.000807] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Iron is an essential element to most microorganisms, yet an excess of iron is toxic. Hence, living cells have to maintain a tight balance between iron uptake and iron consumption and storage. The control of intracellular iron concentrations is particularly challenging for pathogens because mammalian organisms have evolved sophisticated high-affinity systems to sequester iron from microbes and because iron availability fluctuates among the different host niches. In this review, we present the current understanding of iron homeostasis and its regulation in the fungal pathogen Candida glabrata. This yeast is an emerging pathogen which has become the second leading cause of candidemia, a life-threatening invasive mycosis. C. glabrata is relatively poorly studied compared to the closely related model yeast Saccharomyces cerevisiae or to the pathogenic yeast Candida albicans. Still, several research groups have started to identify the actors of C. glabrata iron homeostasis and its transcriptional and post-transcriptional regulation. These studies have revealed interesting particularities of C. glabrata and have shed new light on the evolution of fungal iron homeostasis.
Collapse
Affiliation(s)
- Frédéric Devaux
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, F-75005, Paris, France
| | - Antonin Thiébaut
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, F-75005, Paris, France
| |
Collapse
|
20
|
Pandey AK, Pain J, Dancis A, Pain D. Mitochondria export iron-sulfur and sulfur intermediates to the cytoplasm for iron-sulfur cluster assembly and tRNA thiolation in yeast. J Biol Chem 2019; 294:9489-9502. [PMID: 31040179 DOI: 10.1074/jbc.ra119.008600] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Revised: 04/26/2019] [Indexed: 12/28/2022] Open
Abstract
Iron-sulfur clusters are essential cofactors of proteins. In eukaryotes, iron-sulfur cluster biogenesis requires a mitochondrial iron-sulfur cluster machinery (ISC) and a cytoplasmic iron-sulfur protein assembly machinery (CIA). Here we used mitochondria and cytoplasm isolated from yeast cells, and [35S]cysteine to detect cytoplasmic Fe-35S cluster assembly on a purified apoprotein substrate. We showed that mitochondria generate an intermediate, called (Fe-S)int, needed for cytoplasmic iron-sulfur cluster assembly. The mitochondrial biosynthesis of (Fe-S)int required ISC components such as Nfs1 cysteine desulfurase, Isu1/2 scaffold, and Ssq1 chaperone. Mitochondria then exported (Fe-S)int via the Atm1 transporter in the inner membrane, and we detected (Fe-S)int in active form. When (Fe-S)int was added to cytoplasm, CIA utilized it for iron-sulfur cluster assembly without any further help from the mitochondria. We found that both iron and sulfur for cytoplasmic iron-sulfur cluster assembly originate from the mitochondria, revealing a surprising and novel mitochondrial role. Mitochondrial (Fe-S)int export was most efficient in the presence of cytoplasm containing an apoprotein substrate, suggesting that mitochondria respond to the cytoplasmic demand for iron-sulfur cluster synthesis. Of note, the (Fe-S)int is distinct from the sulfur intermediate called Sint, which is also made and exported by mitochondria but is instead used for cytoplasmic tRNA thiolation. In summary, our findings establish a direct and vital role of mitochondria in cytoplasmic iron-sulfur cluster assembly in yeast cells.
Collapse
Affiliation(s)
- Ashutosh K Pandey
- From the Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey 07103 and
| | - Jayashree Pain
- From the Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey 07103 and
| | - Andrew Dancis
- the Department of Medicine, Division of Hematology-Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Debkumar Pain
- From the Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey 07103 and
| |
Collapse
|
21
|
Martins TS, Costa V, Pereira C. Signaling pathways governing iron homeostasis in budding yeast. Mol Microbiol 2018; 109:422-432. [DOI: 10.1111/mmi.14009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2018] [Indexed: 12/13/2022]
Affiliation(s)
- Telma S. Martins
- I3S-Instituto de Investigação e Inovação em Saúde; Universidade do Porto; Porto Portugal
- IBMC-Instituto de Biologia Molecular e Celular; Universidade do Porto; Porto Portugal
| | - Vítor Costa
- I3S-Instituto de Investigação e Inovação em Saúde; Universidade do Porto; Porto Portugal
- IBMC-Instituto de Biologia Molecular e Celular; Universidade do Porto; Porto Portugal
- Departamento de Biologia Molecular; Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto; Porto Portugal
| | - Clara Pereira
- I3S-Instituto de Investigação e Inovação em Saúde; Universidade do Porto; Porto Portugal
- IBMC-Instituto de Biologia Molecular e Celular; Universidade do Porto; Porto Portugal
- Departamento de Biologia Molecular; Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto; Porto Portugal
| |
Collapse
|
22
|
da Silva SM, Batista-Nascimento L, Gaspar-Cordeiro A, Vernis L, Pimentel C, Rodrigues-Pousada C. Transcriptional regulation of FeS biogenesis genes: A possible shield against arsenate toxicity activated by Yap1. Biochim Biophys Acta Gen Subj 2018; 1862:2152-2161. [PMID: 30025855 DOI: 10.1016/j.bbagen.2018.07.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 06/22/2018] [Accepted: 07/11/2018] [Indexed: 11/26/2022]
Abstract
In the eukaryotic model yeast Saccharomyces cerevisiae, arsenic (As) detoxification is regulated by two transcriptional factors, Yap8 and Yap1. Yap8 specifically controls As extrusion from the cell, whether Yap1 avoids arsenic-induced oxidative damages. Accordingly, cells lacking both Yap1 and Yap8 are more sensitive to arsenate than cells lacking each regulator individually. Strikingly enough, the same sensitivity pattern was observed under anoxia, suggesting that Yap1 role in As detoxification might not be restricted to the regulation of the oxidative stress response. This finding prompted us to study the transcriptomic profile of wild-type and yap1 mutant cells exposed to arsenate. Interestingly, we found that, under such conditions, several genes involved in the biogenesis of FeS proteins were upregulated in a Yap1-dependent way. In line with this observation, arsenate treatment decreases the activity of the mitochondrial aconitase, Aco1, an FeS cluster-containing enzyme, this effect being even more pronounced in the yap1 mutant. Reinforcing the relevance of FeS cluster biogenesis in arsenate detoxification, the overexpression of several ISC and CIA machinery genes alleviates the deleterious effect of arsenate caused by the absence of Yap1 and Yap8. Altogether our data suggest that the upregulation of FeS biogenesis genes regulated by Yap1 might work as a cellular shield against arsenate toxicity.
Collapse
Affiliation(s)
- Sofia M da Silva
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Liliana Batista-Nascimento
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal; Institute of Molecular Biology, 55128 Mainz, Germany
| | - Ana Gaspar-Cordeiro
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Laurence Vernis
- CNRS UMR 3348, Centre Universitaire, 91405 Orsay, France; Institut Curie, PSL Research University, UMR 3348, 91405 Orsay, France; Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, 91405 Orsay, France
| | - Catarina Pimentel
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal.
| | - Claudina Rodrigues-Pousada
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal.
| |
Collapse
|
23
|
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.
Collapse
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.
| |
Collapse
|
24
|
Li L, Kaplan J, Ward DM. The glucose sensor Snf1 and the transcription factors Msn2 and Msn4 regulate transcription of the vacuolar iron importer gene CCC1 and iron resistance in yeast. J Biol Chem 2017; 292:15577-15586. [PMID: 28760824 DOI: 10.1074/jbc.m117.802504] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 07/21/2017] [Indexed: 12/30/2022] Open
Abstract
The budding yeast Saccharomyces cerevisiae stores iron in the vacuole, which is a major resistance mechanism against iron toxicity. One key protein involved in vacuolar iron storage is the iron importer Ccc1, which facilitates iron entry into the vacuole. Transcription of the CCC1 gene is largely regulated by the binding of iron-sulfur clusters to the activator domain of the transcriptional activator Yap5. Additional evidence, however, suggests that Yap5-independent transcriptional activation of CCC1 also contributes to iron resistance. Here, we demonstrate that components of the signaling pathway involving the low-glucose sensor Snf1 regulate CCC1 transcription and iron resistance. We found that SNF1 deletion acts synergistically with YAP5 deletion to regulate CCC1 transcription and iron resistance. A kinase-dead mutation of Snf1 lowered iron resistance as did deletion of SNF4, which encodes a partner protein of Snf1. Deletion of all three alternative partners of Snf1 encoded by SIT1, SIT2, and GAL83 decreased both CCC1 transcription and iron resistance. The Snf1 complex is known to activate the general stress transcription factors Msn2 and Msn4. We show that Msn2 and Msn4 contribute to Snf1-mediated CCC1 transcription. Of note, SNF1 deletion in combination with MSN2 and MSN4 deletion resulted in additive effects on CCC1 transcription, suggesting that other activators contribute to the regulation of CCC1 transcription. In conclusion, we show that yeast have developed multiple transcriptional mechanisms to regulate Ccc1 expression and to protect against high cytosolic iron toxicity.
Collapse
Affiliation(s)
- Liangtao Li
- From the Department of Pathology, Division of Microbiology and Immunology, School of Medicine, University of Utah, Salt Lake City, Utah 84132-2501
| | - Jerry Kaplan
- From the Department of Pathology, Division of Microbiology and Immunology, School of Medicine, University of Utah, Salt Lake City, Utah 84132-2501
| | - Diane M Ward
- From the Department of Pathology, Division of Microbiology and Immunology, School of Medicine, University of Utah, Salt Lake City, Utah 84132-2501
| |
Collapse
|
25
|
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.
Collapse
|
26
|
Eisenberg-Bord M, Schuldiner M. Mitochatting - If only we could be a fly on the cell wall. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:1469-1480. [PMID: 28433686 DOI: 10.1016/j.bbamcr.2017.04.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/07/2017] [Revised: 04/12/2017] [Accepted: 04/18/2017] [Indexed: 12/24/2022]
Abstract
Mitochondria, cellular metabolic hubs, perform many essential processes and are required for the production of metabolites such as ATP, iron-sulfur clusters, heme, amino acids and nucleotides. To fulfill their multiple roles, mitochondria must communicate with all other organelles to exchange small molecules, ions and lipids. Since mitochondria are largely excluded from vesicular trafficking routes, they heavily rely on membrane contact sites. Contact sites are areas of close proximity between organelles that allow efficient transfer of molecules, saving the need for slow and untargeted diffusion through the cytosol. More globally, multiple metabolic pathways require coordination between mitochondria and additional organelles and mitochondrial activity affects all other cellular entities and vice versa. Therefore, uncovering the different means of mitochondrial communication will allow us a better understanding of mitochondria and may illuminate disease processes that occur in the absence of proper cross-talk. In this review we focus on how mitochondria interact with all other organelles and emphasize how this communication is essential for mitochondrial and cellular homeostasis. This article is part of a Special Issue entitled: Membrane Contact Sites edited by Christian Ungermann and Benoit Kornmann.
Collapse
Affiliation(s)
- Michal Eisenberg-Bord
- Department of Molecular Genetics, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, 7610001 Rehovot, Israel.
| |
Collapse
|
27
|
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]
|
28
|
Merhej J, Thiebaut A, Blugeon C, Pouch J, Ali Chaouche MEA, Camadro JM, Le Crom S, Lelandais G, Devaux F. A Network of Paralogous Stress Response Transcription Factors in the Human Pathogen Candida glabrata. Front Microbiol 2016; 7:645. [PMID: 27242683 PMCID: PMC4860858 DOI: 10.3389/fmicb.2016.00645] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Accepted: 04/18/2016] [Indexed: 01/15/2023] Open
Abstract
The yeast Candida glabrata has become the second cause of systemic candidemia in humans. However, relatively few genome-wide studies have been conducted in this organism and our knowledge of its transcriptional regulatory network is quite limited. In the present work, we combined genome-wide chromatin immunoprecipitation (ChIP-seq), transcriptome analyses, and DNA binding motif predictions to describe the regulatory interactions of the seven Yap (Yeast AP1) transcription factors of C. glabrata. We described a transcriptional network containing 255 regulatory interactions and 309 potential target genes. We predicted with high confidence the preferred DNA binding sites for 5 of the 7 CgYaps and showed a strong conservation of the Yap DNA binding properties between S. cerevisiae and C. glabrata. We provided reliable functional annotation for 3 of the 7 Yaps and identified for Yap1 and Yap5 a core regulon which is conserved in S. cerevisiae, C. glabrata, and C. albicans. We uncovered new roles for CgYap7 in the regulation of iron-sulfur cluster biogenesis, for CgYap1 in the regulation of heme biosynthesis and for CgYap5 in the repression of GRX4 in response to iron starvation. These transcription factors define an interconnected transcriptional network at the cross-roads between redox homeostasis, oxygen consumption, and iron metabolism.
Collapse
Affiliation(s)
- Jawad Merhej
- Laboratoire de Biologie Computationnelle et Quantitative, Centre National de la Recherche Scientifique, Institut de Biologie Paris-Seine, UMR 7238, Sorbonne Universités, Université Pierre et Marie Curie Paris, France
| | - Antonin Thiebaut
- Laboratoire de Biologie Computationnelle et Quantitative, Centre National de la Recherche Scientifique, Institut de Biologie Paris-Seine, UMR 7238, Sorbonne Universités, Université Pierre et Marie Curie Paris, France
| | - Corinne Blugeon
- École Normale Supérieure, Paris Sciences et Lettres Research University, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Institut de Biologie de l'École Normale Supérieure, Plateforme Génomique Paris, France
| | - Juliette Pouch
- École Normale Supérieure, Paris Sciences et Lettres Research University, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Institut de Biologie de l'École Normale Supérieure, Plateforme Génomique Paris, France
| | - Mohammed El Amine Ali Chaouche
- École Normale Supérieure, Paris Sciences et Lettres Research University, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Institut de Biologie de l'École Normale Supérieure, Plateforme Génomique Paris, France
| | - Jean-Michel Camadro
- Centre National de la Recherche Scientifique, UMR 7592, Institut Jacques Monod, Université Paris Diderot, Sorbonne Paris Cité Paris, France
| | - Stéphane Le Crom
- Évolution, Centre National de la Recherche Scientifique, Institut de Biologie Paris-Seine, UMR 7138, Sorbonne Universités, Université Pierre et Marie Curie Paris, France
| | - Gaëlle Lelandais
- Centre National de la Recherche Scientifique, UMR 7592, Institut Jacques Monod, Université Paris Diderot, Sorbonne Paris Cité Paris, France
| | - Frédéric Devaux
- Laboratoire de Biologie Computationnelle et Quantitative, Centre National de la Recherche Scientifique, Institut de Biologie Paris-Seine, UMR 7238, Sorbonne Universités, Université Pierre et Marie Curie Paris, France
| |
Collapse
|
29
|
Slavic K, Krishna S, Lahree A, Bouyer G, Hanson KK, Vera I, Pittman JK, Staines HM, Mota MM. A vacuolar iron-transporter homologue acts as a detoxifier in Plasmodium. Nat Commun 2016; 7:10403. [PMID: 26786069 PMCID: PMC4735874 DOI: 10.1038/ncomms10403] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Accepted: 12/07/2015] [Indexed: 01/03/2023] Open
Abstract
Iron is an essential micronutrient but is also highly toxic. In yeast and plant cells, a key detoxifying mechanism involves iron sequestration into intracellular storage compartments, mediated by members of the vacuolar iron-transporter (VIT) family of proteins. Here we study the VIT homologue from the malaria parasites Plasmodium falciparum (PfVIT) and Plasmodium berghei (PbVIT). PfVIT-mediated iron transport in a yeast heterologous expression system is saturable (Km ∼ 14.7 μM), and selective for Fe(2+) over other divalent cations. PbVIT-deficient P. berghei lines (Pbvit(-)) show a reduction in parasite load in both liver and blood stages of infection in mice. Moreover, Pbvit(-) parasites have higher levels of labile iron in blood stages and are more sensitive to increased iron levels in liver stages, when compared with wild-type parasites. Our data are consistent with Plasmodium VITs playing a major role in iron detoxification and, thus, normal development of malaria parasites in their mammalian host.
Collapse
Affiliation(s)
- Ksenija Slavic
- Instituto de Medicina Molecular, Faculdade de Medicina Universidade de Lisboa, 1649-028 Lisbon, Portugal
| | - Sanjeev Krishna
- Institute for Infection & Immunity, St. George's, University of London, London SW17 0RE, UK
| | - Aparajita Lahree
- Instituto de Medicina Molecular, Faculdade de Medicina Universidade de Lisboa, 1649-028 Lisbon, Portugal
| | - Guillaume Bouyer
- Institute for Infection & Immunity, St. George's, University of London, London SW17 0RE, UK
- Sorbonne Universités, UPMC Univ Paris 6, CNRS, UMR 8227, Comparative Physiology of Erythrocytes, Station Biologique de Roscoff, CS 90074, 29688 Roscoff, France
| | - Kirsten K. Hanson
- Instituto de Medicina Molecular, Faculdade de Medicina Universidade de Lisboa, 1649-028 Lisbon, Portugal
- Present address: University of Texas at San Antonio, Department of Biology and STCEID, San Antonio, Texas 78249, USA
| | - Iset Vera
- Instituto de Medicina Molecular, Faculdade de Medicina Universidade de Lisboa, 1649-028 Lisbon, Portugal
| | - Jon K. Pittman
- Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
| | - Henry M. Staines
- Institute for Infection & Immunity, St. George's, University of London, London SW17 0RE, UK
| | - Maria M. Mota
- Instituto de Medicina Molecular, Faculdade de Medicina Universidade de Lisboa, 1649-028 Lisbon, Portugal
| |
Collapse
|
30
|
Wofford JD, Lindahl PA. Mitochondrial Iron-Sulfur Cluster Activity and Cytosolic Iron Regulate Iron Traffic in Saccharomyces cerevisiae. J Biol Chem 2015; 290:26968-26977. [PMID: 26306041 PMCID: PMC4646409 DOI: 10.1074/jbc.m115.676668] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 08/17/2015] [Indexed: 11/06/2022] Open
Abstract
An ordinary differential equation-based mathematical model was developed to describe trafficking and regulation of iron in growing fermenting budding yeast. Accordingly, environmental iron enters the cytosol and moves into mitochondria and vacuoles. Dilution caused by increasing cell volume is included. Four sites are regulated, including those in which iron is imported into the cytosol, mitochondria, and vacuoles, and the site at which vacuolar Fe(II) is oxidized to Fe(III). The objective of this study was to determine whether cytosolic iron (Fecyt) and/or a putative sulfur-based product of iron-sulfur cluster (ISC) activity was/were being sensed in regulation. The model assumes that the matrix of healthy mitochondria is anaerobic, and that in ISC mutants, O2 diffuses into the matrix where it reacts with nonheme high spin Fe(II) ions, oxidizing them to nanoparticles and generating reactive oxygen species. This reactivity causes a further decline in ISC/heme biosynthesis, which ultimately gives rise to the diseased state. The ordinary differential equations that define this model were numerically integrated, and concentrations of each component were plotted versus the concentration of iron in the growth medium and versus the rate of ISC/heme biosynthesis. Model parameters were optimized by fitting simulations to literature data. The model variant that assumed that both Fecyt and ISC biosynthesis activity were sensed in regulation mimicked observed behavior best. Such "dual sensing" probably arises in real cells because regulation involves assembly of an ISC on a cytosolic protein using Fecyt and a sulfur species generated in mitochondria during ISC biosynthesis and exported into the cytosol.
Collapse
Affiliation(s)
- Joshua D Wofford
- Departments of Chemistry, Texas A & M University, College Station, Texas 77843
| | - Paul A Lindahl
- Departments of Chemistry, Texas A & M University, College Station, Texas 77843; Departments of Chemistry, Biochemistry and Biophysics, Texas A & M University, College Station, Texas 77843.
| |
Collapse
|
31
|
Cellular sensing and transport of metal ions: implications in micronutrient homeostasis. J Nutr Biochem 2015; 26:1103-15. [PMID: 26342943 DOI: 10.1016/j.jnutbio.2015.08.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 07/23/2015] [Accepted: 08/04/2015] [Indexed: 12/15/2022]
Abstract
Micronutrients include the transition metal ions zinc, copper and iron. These metals are essential for life as they serve as cofactors for many different proteins. On the other hand, they can also be toxic to cell growth when in excess. As a consequence, all organisms require mechanisms to tightly regulate the levels of these metal ions. In eukaryotes, one of the primary ways in which metal levels are regulated is through changes in expression of genes required for metal uptake, compartmentalization, storage and export. By tightly regulating the expression of these genes, each organism is able to balance metal levels despite fluctuations in the diet or extracellular environment. The goal of this review is to provide an overview of how gene expression can be controlled at a transcriptional, posttranscriptional and posttranslational level in response to metal ions in lower and higher eukaryotes. Specifically, I review what is known about how these metalloregulatory factors sense fluctuations in metal ion levels and how changes in gene expression maintain nutrient homeostasis.
Collapse
|
32
|
Compartmentalization of iron between mitochondria and the cytosol and its regulation. Eur J Cell Biol 2015; 94:292-308. [DOI: 10.1016/j.ejcb.2015.05.003] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
|
33
|
The basic leucine zipper stress response regulator Yap5 senses high-iron conditions by coordination of [2Fe-2S] clusters. Mol Cell Biol 2014; 35:370-8. [PMID: 25368382 DOI: 10.1128/mcb.01033-14] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Iron is an essential, yet at elevated concentrations toxic trace element. To date, the mechanisms of iron sensing by eukaryotic iron-responsive transcription factors are poorly understood. The Saccharomyces cerevisiae transcription factor Yap5, a member of the Yap family of bZIP stress response regulators, administrates the adaptive response to high-iron conditions. Despite the central role of the iron-sensing process for cell viability, the molecule perceived by Yap5 and the underlying regulatory mechanisms are unknown. Here, we show that Yap5 senses high-iron conditions by two Fe/S clusters bound to its activator domain (Yap5-AD). The more stable iron-regulatory Fe/S cluster at the N-terminal cysteine-rich domain (n-CRD) of Yap5 is detected in vivo and in vitro. The second cluster coordinated by the C-terminal CRD can only be shown after chemical reconstitution, since it is bound in a labile fashion. Both clusters are of the [2Fe-2S] type as characterized by UV/visible (UV/Vis), circular dichroism, electron paramagnetic resonance (EPR), and Mössbauer spectroscopy. Fe/S cluster binding to Yap5-AD induces a conformational change that may activate transcription. The cluster-binding motif of the n-CRD domain is highly conserved in HapX-like transcription factors of pathogenic fungi and thus may represent a general sensor module common to many eukaryotic stress response regulators.
Collapse
|
34
|
Gsaller F, Hortschansky P, Beattie SR, Klammer V, Tuppatsch K, Lechner BE, Rietzschel N, Werner ER, Vogan AA, Chung D, Mühlenhoff U, Kato M, Cramer RA, Brakhage AA, Haas H. The Janus transcription factor HapX controls fungal adaptation to both iron starvation and iron excess. EMBO J 2014; 33:2261-76. [PMID: 25092765 PMCID: PMC4232046 DOI: 10.15252/embj.201489468] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Balance of physiological levels of iron is essential for every organism. In Aspergillus fumigatus and other fungal pathogens, the transcription factor HapX mediates adaptation to iron limitation and consequently virulence by repressing iron consumption and activating iron uptake. Here, we demonstrate that HapX is also essential for iron resistance via activating vacuolar iron storage. We identified HapX protein domains that are essential for HapX functions during either iron starvation or high-iron conditions. The evolutionary conservation of these domains indicates their wide-spread role in iron sensing. We further demonstrate that a HapX homodimer and the CCAAT-binding complex (CBC) cooperatively bind an evolutionary conserved DNA motif in a target promoter. The latter reveals the mode of discrimination between general CBC and specific HapX/CBC target genes. Collectively, our study uncovers a novel regulatory mechanism mediating both iron resistance and adaptation to iron starvation by the same transcription factor complex with activating and repressing functions depending on ambient iron availability.
Collapse
Affiliation(s)
- Fabio Gsaller
- Division of Molecular Biology, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Peter Hortschansky
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany
| | - Sarah R Beattie
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Veronika Klammer
- Division of Molecular Biology, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Katja Tuppatsch
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany Friedrich Schiller University, Jena, Germany
| | - Beatrix E Lechner
- Division of Molecular Biology, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Nicole Rietzschel
- Institut für Zytobiologie und Zytopathologie, Philipps-Universität Marburg, Marburg, Germany
| | - Ernst R Werner
- Division of Biological Chemistry, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Aaron A Vogan
- Department of Biology, McMaster University, Hamilton, ON, Canada
| | - Dawoon Chung
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Ulrich Mühlenhoff
- Institut für Zytobiologie und Zytopathologie, Philipps-Universität Marburg, Marburg, Germany
| | - Masashi Kato
- Faculty of Agriculture, Meijo University, Nagoya, Japan
| | - Robert A Cramer
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Axel A Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany Friedrich Schiller University, Jena, Germany
| | - Hubertus Haas
- Division of Molecular Biology, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| |
Collapse
|
35
|
Foster AW, Dainty SJ, Patterson CJ, Pohl E, Blackburn H, Wilson C, Hess CR, Rutherford JC, Quaranta L, Corran A, Robinson NJ. A chemical potentiator of copper-accumulation used to investigate the iron-regulons of Saccharomyces cerevisiae. Mol Microbiol 2014; 93:317-30. [PMID: 24895027 PMCID: PMC4149784 DOI: 10.1111/mmi.12661] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/29/2014] [Indexed: 12/29/2022]
Abstract
The extreme resistance of Saccharomyces cerevisiae to copper is overcome by 2-(6-benzyl-2-pyridyl)quinazoline (BPQ), providing a chemical-biology tool which has been exploited in two lines of discovery. First, BPQ is shown to form a red (BPQ)2Cu(I) complex and promote Ctr1-independent copper-accumulation in whole cells and in mitochondria isolated from treated cells. Multiple phenotypes, including loss of aconitase activity, are consistent with copper-BPQ mediated damage to mitochondrial iron–sulphur clusters. Thus, a biochemical basis of copper-toxicity in S. cerevisiae is analogous to other organisms. Second, iron regulons controlled by Aft1/2, Cth2 and Yap5 that respond to mitochondrial iron–sulphur cluster status are modulated by copper-BPQ causing iron hyper-accumulation via upregulated iron-import. Comparison of copper-BPQ treated, untreated and copper-only treated wild-type and fra2Δ by RNA-seq has uncovered a new candidate Aft1 target-gene (LSO1) and paralogous non-target (LSO2), plus nine putative Cth2 target-transcripts. Two lines of evidence confirm that Fra2 dominates basal repression of the Aft1/2 regulons in iron-replete cultures. Fra2-independent control of these regulons is also observed but CTH2 itself appears to be atypically Fra2-dependent. However, control of Cth2-target transcripts which is independent of CTH2 transcript abundance or of Fra2, is also quantified. Use of copper-BPQ supports a substantial contribution of metabolite repression to iron-regulation.
Collapse
Affiliation(s)
- Andrew W Foster
- Department of Chemistry, School of Biological and Biomedical Sciences, Durham University, Durham, DH1 3LE, UK
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Gudipati V, Koch K, Lienhart WD, Macheroux P. The flavoproteome of the yeast Saccharomyces cerevisiae. BIOCHIMICA ET BIOPHYSICA ACTA 2014; 1844:535-44. [PMID: 24373875 PMCID: PMC3991850 DOI: 10.1016/j.bbapap.2013.12.015] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 12/18/2013] [Accepted: 12/21/2013] [Indexed: 01/29/2023]
Abstract
Genome analysis of the yeast Saccharomyces cerevisiae identified 68 genes encoding flavin-dependent proteins (1.1% of protein encoding genes) to which 47 distinct biochemical functions were assigned. The majority of flavoproteins operate in mitochondria where they participate in redox processes revolving around the transfer of electrons to the electron transport chain. In addition, we found that flavoenzymes play a central role in various aspects of iron metabolism, such as iron uptake, the biogenesis of iron-sulfur clusters and insertion of the heme cofactor into apocytochromes. Another important group of flavoenzymes is directly (Dus1-4p and Mto1p) or indirectly (Tyw1p) involved in reactions leading to tRNA-modifications. Despite the wealth of genetic information available for S. cerevisiae, we were surprised that many flavoproteins are poorly characterized biochemically. For example, the role of the yeast flavodoxins Pst2p, Rfs1p and Ycp4p with regard to their electron donor and acceptor is presently unknown. Similarly, the function of the heterodimeric Aim45p/Cir1p, which is homologous to the electron-transferring flavoproteins of higher eukaryotes, in electron transfer processes occurring in the mitochondrial matrix remains to be elucidated. This lack of information extends to the five membrane proteins involved in riboflavin or FAD transport as well as FMN and FAD homeostasis within the yeast cell. Nevertheless, several yeast flavoproteins, were identified as convenient model systems both in terms of their mechanism of action as well as structurally to improve our understanding of diseases caused by dysfunctional human flavoprotein orthologs.
Collapse
Affiliation(s)
- Venugopal Gudipati
- Graz University of Technology, Institute of Biochemistry, Petersgasse 12, A-8010 Graz, Austria
| | - Karin Koch
- Graz University of Technology, Institute of Biochemistry, Petersgasse 12, A-8010 Graz, Austria
| | - Wolf-Dieter Lienhart
- Graz University of Technology, Institute of Biochemistry, Petersgasse 12, A-8010 Graz, Austria
| | - Peter Macheroux
- Graz University of Technology, Institute of Biochemistry, Petersgasse 12, A-8010 Graz, Austria.
| |
Collapse
|
37
|
Outten CE, Albetel AN. Iron sensing and regulation in Saccharomyces cerevisiae: Ironing out the mechanistic details. Curr Opin Microbiol 2013; 16:662-8. [PMID: 23962819 DOI: 10.1016/j.mib.2013.07.020] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 07/29/2013] [Indexed: 01/26/2023]
Abstract
Regulation of iron metabolism in Saccharomyces cerevisiae is achieved at the transcriptional level by low (Aft1 and Aft2) and high iron-sensing (Yap5) transcription factors, and at the post-transcriptional level by mRNA-binding proteins (Cth1 and Cth2). In this review we highlight recent studies unveiling the critical role that iron-sulfur clusters play in control of Aft1/2 and Yap5 activity, as well as the complex relationship between iron homeostasis and thiol redox metabolism. In addition, new insights into the localization and regulation of Cth1/Cth2 have added another layer of complexity to the cell's adaptation to iron deficiency. Finally, biophysical studies on subcellular iron speciation changes in response to environmental and genetic factors have further illuminated the elaborate control mechanisms required to manage iron bioavailability in the cell.
Collapse
Affiliation(s)
- Caryn E Outten
- Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter St., Columbia, SC 29208, USA.
| | | |
Collapse
|
38
|
Abstract
This chapter is focused on the iron metallome in eukaryotes at the cellular and subcellular level, including properties, utilization in metalloproteins, trafficking, storage, and regulation of these processes. Studies in the model eukaryote Saccharomyces cerevisiae and mammalian cells will be highlighted. The discussion of iron properties will center on the speciation and localization of intracellular iron as well as the cellular and molecular mechanisms for coping with both low iron bioavailability and iron toxicity. The section on iron metalloproteins will emphasize heme, iron-sulfur cluster, and non-heme iron centers, particularly their cellular roles and mechanisms of assembly. The section on iron uptake, trafficking, and storage will compare methods used by yeast and mammalian cells to import iron, how this iron is brought into various organelles, and types of iron storage proteins. Regulation of these processes will be compared between yeast and mammalian cells at the transcriptional, post-transcriptional, and post-translational levels.
Collapse
Affiliation(s)
- Adrienne C. Dlouhy
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA
| | - Caryn E. Outten
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA
| |
Collapse
|
39
|
Lill R, Hoffmann B, Molik S, Pierik AJ, Rietzschel N, Stehling O, Uzarska MA, Webert H, Wilbrecht C, Mühlenhoff U. The role of mitochondria in cellular iron-sulfur protein biogenesis and iron metabolism. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1823:1491-508. [PMID: 22609301 DOI: 10.1016/j.bbamcr.2012.05.009] [Citation(s) in RCA: 364] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 05/07/2012] [Accepted: 05/09/2012] [Indexed: 12/21/2022]
Abstract
Mitochondria play a key role in iron metabolism in that they synthesize heme, assemble iron-sulfur (Fe/S) proteins, and participate in cellular iron regulation. Here, we review the latter two topics and their intimate connection. The mitochondrial Fe/S cluster (ISC) assembly machinery consists of 17 proteins that operate in three major steps of the maturation process. First, the cysteine desulfurase complex Nfs1-Isd11 as the sulfur donor cooperates with ferredoxin-ferredoxin reductase acting as an electron transfer chain, and frataxin to synthesize an [2Fe-2S] cluster on the scaffold protein Isu1. Second, the cluster is released from Isu1 and transferred toward apoproteins with the help of a dedicated Hsp70 chaperone system and the glutaredoxin Grx5. Finally, various specialized ISC components assist in the generation of [4Fe-4S] clusters and cluster insertion into specific target apoproteins. Functional defects of the core ISC assembly machinery are signaled to cytosolic or nuclear iron regulatory systems resulting in increased cellular iron acquisition and mitochondrial iron accumulation. In fungi, regulation is achieved by iron-responsive transcription factors controlling the expression of genes involved in iron uptake and intracellular distribution. They are assisted by cytosolic multidomain glutaredoxins which use a bound Fe/S cluster as iron sensor and additionally perform an essential role in intracellular iron delivery to target metalloproteins. In mammalian cells, the iron regulatory proteins IRP1, an Fe/S protein, and IRP2 act in a post-transcriptional fashion to adjust the cellular needs for iron. Thus, Fe/S protein biogenesis and cellular iron metabolism are tightly linked to coordinate iron supply and utilization. This article is part of a Special Issue entitled: Cell Biology of Metals.
Collapse
Affiliation(s)
- Roland Lill
- Institut für Zytobiologie und Zytopathologie, Philipps-Universität Marburg, Robert-Koch Str. 6, 35033 Marburg, Germany.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Li L, Miao R, Bertram S, Jia X, Ward DM, Kaplan J. A role for iron-sulfur clusters in the regulation of transcription factor Yap5-dependent high iron transcriptional responses in yeast. J Biol Chem 2012; 287:35709-35721. [PMID: 22915593 DOI: 10.1074/jbc.m112.395533] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Yeast respond to increased cytosolic iron by activating the transcription factor Yap5 increasing transcription of CCC1, which encodes a vacuolar iron importer. Using a genetic screen to identify genes involved in Yap5 iron sensing, we discovered that a mutation in SSQ1, which encodes a mitochondrial chaperone involved in iron-sulfur cluster synthesis, prevented expression of Yap5 target genes. We demonstrated that mutation or reduced expression of other genes involved in mitochondrial iron-sulfur cluster synthesis (YFH1, ISU1) prevented induction of the Yap5 response. We took advantage of the iron-dependent catalytic activity of Pseudaminobacter salicylatoxidans gentisate 1,2-dioxygenase expressed in yeast to measure changes in cytosolic iron. We determined that reductions in iron-sulfur cluster synthesis did not affect the activity of cytosolic gentisate 1,2-dioxygenase. We show that loss of activity of the cytosolic iron-sulfur cluster assembly complex proteins or deletion of cytosolic glutaredoxins did not reduce expression of Yap5 target genes. These results suggest that the high iron transcriptional response, as well as the low iron transcriptional response, senses iron-sulfur clusters.
Collapse
Affiliation(s)
- Liangtao Li
- Department of Pathology, School of Medicine, University of Utah, Salt Lake City, Utah 84132
| | - Ren Miao
- Department of Pathology, School of Medicine, University of Utah, Salt Lake City, Utah 84132
| | - Sophie Bertram
- Department of Pathology, School of Medicine, University of Utah, Salt Lake City, Utah 84132
| | - Xuan Jia
- Department of Pathology, School of Medicine, University of Utah, Salt Lake City, Utah 84132
| | - Diane M Ward
- Department of Pathology, School of Medicine, University of Utah, Salt Lake City, Utah 84132
| | - Jerry Kaplan
- Department of Pathology, School of Medicine, University of Utah, Salt Lake City, Utah 84132.
| |
Collapse
|
41
|
Li H, Outten CE. Monothiol CGFS glutaredoxins and BolA-like proteins: [2Fe-2S] binding partners in iron homeostasis. Biochemistry 2012; 51:4377-89. [PMID: 22583368 DOI: 10.1021/bi300393z] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Monothiol glutaredoxins (Grxs) with a signature CGFS active site and BolA-like proteins have recently emerged as novel players in iron homeostasis. Elegant genetic and biochemical studies examining the functional and physical interactions of CGFS Grxs in the fungi Saccharomyces cerevisiae and Schizosaccharomyces pombe have unveiled their essential roles in intracellular iron signaling, iron trafficking, and the maturation of Fe-S cluster proteins. Biophysical and biochemical analyses of the [2Fe-2S] bridging interaction between CGFS Grxs and a BolA-like protein in S. cerevisiae provided the first molecular-level understanding of the iron regulation mechanism in this model eukaryote and established the ubiquitous CGFS Grxs and BolA-like proteins as novel Fe-S cluster-binding regulatory partners. Parallel studies focused on Escherichia coli and human homologues for CGFS Grxs and BolA-like proteins have supported the studies in yeast and provided additional clues about their involvement in cellular iron metabolism. Herein, we review recent progress in uncovering the cellular and molecular mechanisms by which CGFS Grxs and BolA-like proteins help regulate iron metabolism in both eukaryotic and prokaryotic organisms.
Collapse
Affiliation(s)
- Haoran Li
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | | |
Collapse
|
42
|
Pimentel C, Vicente C, Menezes RA, Caetano S, Carreto L, Rodrigues-Pousada C. The role of the Yap5 transcription factor in remodeling gene expression in response to Fe bioavailability. PLoS One 2012; 7:e37434. [PMID: 22616008 PMCID: PMC3353947 DOI: 10.1371/journal.pone.0037434] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 04/19/2012] [Indexed: 01/02/2023] Open
Abstract
The budding yeast Saccharomyces cerevisiae has developed several mechanisms to avoid either the drastic consequences of iron deprivation or the toxic effects of iron excess. In this work, we analysed the global gene expression changes occurring in yeast cells undergoing iron overload. Several genes directly or indirectly involved in iron homeostasis showed altered expression and the relevance of these changes are discussed. Microarray analyses were also performed to identify new targets of the iron responsive factor Yap5. Besides the iron vacuolar transporter CCC1, Yap5 also controls the expression of glutaredoxin GRX4, previously known to be involved in the regulation of Aft1 nuclear localization. Consistently, we show that in the absence of Yap5 Aft1 nuclear exclusion is slightly impaired. These studies provide further evidence that cells control iron homeostasis by using multiple pathways.
Collapse
Affiliation(s)
- Catarina Pimentel
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Cristina Vicente
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Regina Andrade Menezes
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Soraia Caetano
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Laura Carreto
- Department of Biology, Center for Environmental and Marine Studies, Universidade de Aveiro, Aveiro, Portugal
| | | |
Collapse
|