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Fernandez S, Wofford JD, Shepherd RE, Vali SW, Dancis A, Lindahl PA. Yeast cells depleted of the frataxin homolog Yfh1 redistribute cellular iron: Studies using Mössbauer spectroscopy and mathematical modeling. J Biol Chem 2022; 298:101921. [PMID: 35413285 PMCID: PMC9130540 DOI: 10.1016/j.jbc.2022.101921] [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: 02/01/2022] [Revised: 04/05/2022] [Accepted: 04/06/2022] [Indexed: 11/27/2022] Open
Abstract
The neurodegenerative disease Friedreich's ataxia arises from a deficiency of frataxin, a protein that promotes iron-sulfur cluster (ISC) assembly in mitochondria. Here, primarily using Mössbauer spectroscopy, we investigated the iron content of a yeast strain in which expression of yeast frataxin homolog 1 (Yfh1), oxygenation conditions, iron concentrations, and metabolic modes were varied. We found that aerobic fermenting Yfh1-depleted cells grew slowly and accumulated FeIII nanoparticles, unlike WT cells. Under hypoxic conditions, the same mutant cells grew at rates similar to WT cells, had similar iron content, and were dominated by FeII rather than FeIII nanoparticles. Furthermore, mitochondria from mutant hypoxic cells contained approximately the same levels of ISCs as WT cells, confirming that Yfh1 is not required for ISC assembly. These cells also did not accumulate excessive iron, indicating that iron accumulation into yfh1-deficient mitochondria is stimulated by O2. In addition, in aerobic WT cells, we found that vacuoles stored FeIII, whereas under hypoxic fermenting conditions, vacuolar iron was reduced to FeII. Under respiring conditions, vacuoles of Yfh1-deficient cells contained FeIII, and nanoparticles accumulated only under aerobic conditions. Taken together, these results informed a mathematical model of iron trafficking and regulation in cells that could semiquantitatively simulate the Yfh1-deficiency phenotype. Simulations suggested partially independent regulation in which cellular iron import is regulated by ISC activity in mitochondria, mitochondrial iron import is regulated by a mitochondrial FeII pool, and vacuolar iron import is regulated by cytosolic FeII and mitochondrial ISC activity.
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Affiliation(s)
- Salvador Fernandez
- Department of Chemistry, Texas A&M University, College Station, Texas, USA
| | - Joshua D Wofford
- Department of Chemistry, College of Science and Mathematics, Charleston Southern University, Charleston South Carolina, USA
| | - Rachel E Shepherd
- Department of Chemistry, Texas A&M University, College Station, Texas, USA
| | - Shaik Waseem Vali
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA
| | - Andrew Dancis
- Department of Medicine, Division of Hematology-Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Paul A Lindahl
- Department of Chemistry, Texas A&M University, College Station, Texas, USA; Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA.
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Monfort B, Want K, Gervason S, D’Autréaux B. Recent Advances in the Elucidation of Frataxin Biochemical Function Open Novel Perspectives for the Treatment of Friedreich’s Ataxia. Front Neurosci 2022; 16:838335. [PMID: 35310092 PMCID: PMC8924461 DOI: 10.3389/fnins.2022.838335] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 01/28/2022] [Indexed: 12/25/2022] Open
Abstract
Friedreich’s ataxia (FRDA) is the most prevalent autosomic recessive ataxia and is associated with a severe cardiac hypertrophy and less frequently diabetes. It is caused by mutations in the gene encoding frataxin (FXN), a small mitochondrial protein. The primary consequence is a defective expression of FXN, with basal protein levels decreased by 70–98%, which foremost affects the cerebellum, dorsal root ganglia, heart and liver. FXN is a mitochondrial protein involved in iron metabolism but its exact function has remained elusive and highly debated since its discovery. At the cellular level, FRDA is characterized by a general deficit in the biosynthesis of iron-sulfur (Fe-S) clusters and heme, iron accumulation and deposition in mitochondria, and sensitivity to oxidative stress. Based on these phenotypes and the proposed ability of FXN to bind iron, a role as an iron storage protein providing iron for Fe-S cluster and heme biosynthesis was initially proposed. However, this model was challenged by several other studies and it is now widely accepted that FXN functions primarily in Fe-S cluster biosynthesis, with iron accumulation, heme deficiency and oxidative stress sensitivity appearing later on as secondary defects. Nonetheless, the biochemical function of FXN in Fe-S cluster biosynthesis is still debated. Several roles have been proposed for FXN: iron chaperone, gate-keeper of detrimental Fe-S cluster biosynthesis, sulfide production stimulator and sulfur transfer accelerator. A picture is now emerging which points toward a unique function of FXN as an accelerator of a key step of sulfur transfer between two components of the Fe-S cluster biosynthetic complex. These findings should foster the development of new strategies for the treatment of FRDA. We will review here the latest discoveries on the biochemical function of frataxin and the implication for a potential therapeutic treatment of FRDA.
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Mitochondrial De Novo Assembly of Iron–Sulfur Clusters in Mammals: Complex Matters in a Complex That Matters. INORGANICS 2022. [DOI: 10.3390/inorganics10030031] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/10/2022] Open
Abstract
Iron–sulfur clusters (Fe–S or ISC) are essential cofactors that function in a wide range of biological pathways. In mammalian cells, Fe–S biosynthesis primarily relies on mitochondria and involves a concerted group of evolutionary-conserved proteins forming the ISC pathway. In the early stage of the ISC pathway, the Fe–S core complex is required for de novo assembly of Fe–S. In humans, the Fe–S core complex comprises the cysteine desulfurase NFS1, the scaffold protein ISCU2, frataxin (FXN), the ferredoxin FDX2, and regulatory/accessory proteins ISD11 and Acyl Carrier Protein (ACP). In recent years, the field has made significant advances in unraveling the structure of the Fe–S core complex and the mechanism underlying its function. Herein, we review the key recent findings related to the Fe–S core complex and its components. We highlight some of the unanswered questions and provide a model of the Fe–S assembly within the complex. In addition, we briefly touch on the genetic diseases associated with mutations in the Fe–S core complex components.
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Pujol-Carrion N, Gonzalez-Alfonso A, Puig S, de la Torre-Ruiz MA. Both human and soya bean ferritins highly improve the accumulation of bioavailable iron and contribute to extend the chronological life in budding yeast. Microb Biotechnol 2021; 15:1525-1541. [PMID: 34644442 PMCID: PMC9049602 DOI: 10.1111/1751-7915.13939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 09/16/2021] [Accepted: 09/17/2021] [Indexed: 12/02/2022] Open
Abstract
Ferritin proteins have an enormous capacity to store iron in cells. In search for the best conditions to accumulate and store bioavailable iron, we made use of a double mutant null for the monothiol glutaredoxins GRX3 and GRX4. The strain grx3grx4 accumulates high iron concentrations in the cytoplasm, making the metal easily available for ferritin chelation. Here, we perform a comparative study between human (L and H) and soya bean ferritins (H1 and H2) function in the eukaryotic system Saccharomyces cerevisiae. We demonstrate that the four human and soya bean ferritin chains are successfully expressed in our model system. Upon coexpression of either both human or soya bean ferritin chains, respiratory conditions along with iron supplementation led us to obtain the maximum yields of iron stored in yeast described to date. Human and soya bean ferritin chains are functional and present equivalent properties as promoters of cell survival in iron overload conditions. The best system revealed that the four human and soya bean ferritins possess a novel function as anti‐ageing proteins in conditions of iron excess. In this respect, both ferritin chains with oxidoreductase capacity (human‐H and soya bean‐H2) bear the highest capacity to extend life suggesting the possibility of an evolutionary conservation.
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Affiliation(s)
- Nuria Pujol-Carrion
- Cell Signalling in Yeast Unit, Department of Basic Medical Sciences, Institut de Recerca Biomèdica de Lleida (IRBLleida), University of Lleida, Lleida, 25198, Spain
| | - Alma Gonzalez-Alfonso
- Cell Signalling in Yeast Unit, Department of Basic Medical Sciences, Institut de Recerca Biomèdica de Lleida (IRBLleida), University of Lleida, Lleida, 25198, Spain
| | - Sergi Puig
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Paterna, Valencia, E-46980, Spain
| | - Maria Angeles de la Torre-Ruiz
- Cell Signalling in Yeast Unit, Department of Basic Medical Sciences, Institut de Recerca Biomèdica de Lleida (IRBLleida), University of Lleida, Lleida, 25198, Spain
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Doni D, Passerini L, Audran G, Marque SRA, Schulz M, Santos J, Costantini P, Bortolus M, Carbonera D. Effects of Fe 2+/Fe 3+ Binding to Human Frataxin and Its D122Y Variant, as Revealed by Site-Directed Spin Labeling (SDSL) EPR Complemented by Fluorescence and Circular Dichroism Spectroscopies. Int J Mol Sci 2020; 21:E9619. [PMID: 33348670 PMCID: PMC7766144 DOI: 10.3390/ijms21249619] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 12/11/2020] [Accepted: 12/15/2020] [Indexed: 12/17/2022] Open
Abstract
Frataxin is a highly conserved protein whose deficiency results in the neurodegenerative disease Friederich's ataxia. Frataxin's actual physiological function has been debated for a long time without reaching a general agreement; however, it is commonly accepted that the protein is involved in the biosynthetic iron-sulphur cluster (ISC) machinery, and several authors have pointed out that it also participates in iron homeostasis. In this work, we use site-directed spin labeling coupled to electron paramagnetic resonance (SDSL EPR) to add new information on the effects of ferric and ferrous iron binding on the properties of human frataxin in vitro. Using SDSL EPR and relating the results to fluorescence experiments commonly performed to study iron binding to FXN, we produced evidence that ferric iron causes reversible aggregation without preferred interfaces in a concentration-dependent fashion, starting at relatively low concentrations (micromolar range), whereas ferrous iron binds without inducing aggregation. Moreover, our experiments show that the ferrous binding does not lead to changes of protein conformation. The data reported in this study reveal that the currently reported binding stoichiometries should be taken with caution. The use of a spin label resistant to reduction, as well as the comparison of the binding effect of Fe2+ in wild type and in the pathological D122Y variant of frataxin, allowed us to characterize the Fe2+ binding properties of different protein sites and highlight the effect of the D122Y substitution on the surrounding residues. We suggest that both Fe2+ and Fe3+ might play a relevant role in the context of the proposed FXN physiological functions.
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Affiliation(s)
- Davide Doni
- Department of Biology, University of Padova, Viale G. Colombo 3, 35131 Padova, Italy; (D.D.); (P.C.)
| | - Leonardo Passerini
- Department of Chemical Sciences, University of Padova, Via F. Marzolo 1, 35131 Padova, Italy; (L.P.); (D.C.)
| | - Gérard Audran
- Institut de Chimie Radicalaire, Aix Marseille Universitè, CNRS, ICR, UMR 7273, Case 551, Ave Escadrille Normandie Niemen, CEDEX 20, 13397 Marseille, France; (G.A.); (S.R.A.M.); (M.S.)
| | - Sylvain R. A. Marque
- Institut de Chimie Radicalaire, Aix Marseille Universitè, CNRS, ICR, UMR 7273, Case 551, Ave Escadrille Normandie Niemen, CEDEX 20, 13397 Marseille, France; (G.A.); (S.R.A.M.); (M.S.)
| | - Marvin Schulz
- Institut de Chimie Radicalaire, Aix Marseille Universitè, CNRS, ICR, UMR 7273, Case 551, Ave Escadrille Normandie Niemen, CEDEX 20, 13397 Marseille, France; (G.A.); (S.R.A.M.); (M.S.)
| | - Javier Santos
- Departamento de Química Biológica, Instituto de Biociencias, Biotecnología y Biomedicina (iB3-UBA), Facultad de Ciencia Exactas y Naturales, Universidad de Buenos Aires, Intendente Güiraldes 2160—Ciudad Universitaria, 1428EGA CONICET, Godoy Cruz 2290, Buenos Aires C1425FQB, Argentina;
- Instituto de Química y Fisicoquímica Biológicas Dr. Alejandro Paladini, Universidad de Buenos Aires, CONICET, Junín 956, Buenos Aires 1113AAD, Argentina
| | - Paola Costantini
- Department of Biology, University of Padova, Viale G. Colombo 3, 35131 Padova, Italy; (D.D.); (P.C.)
| | - Marco Bortolus
- Department of Chemical Sciences, University of Padova, Via F. Marzolo 1, 35131 Padova, Italy; (L.P.); (D.C.)
| | - Donatella Carbonera
- Department of Chemical Sciences, University of Padova, Via F. Marzolo 1, 35131 Padova, Italy; (L.P.); (D.C.)
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Abstract
Iron–sulfur (Fe–S) clusters are protein cofactors of a multitude of enzymes performing essential biological functions. Specialized multi-protein machineries present in all types of organisms support their biosynthesis. These machineries encompass a scaffold protein on which Fe–S clusters are assembled and a cysteine desulfurase that provides sulfur in the form of a persulfide. The sulfide ions are produced by reductive cleavage of the persulfide, which involves specific reductase systems. Several other components are required for Fe–S biosynthesis, including frataxin, a key protein of controversial function and accessory components for insertion of Fe–S clusters in client proteins. Fe–S cluster biosynthesis is thought to rely on concerted and carefully orchestrated processes. However, the elucidation of the mechanisms of their assembly has remained a challenging task due to the biochemical versatility of iron and sulfur and the relative instability of Fe–S clusters. Nonetheless, significant progresses have been achieved in the past years, using biochemical, spectroscopic and structural approaches with reconstituted system in vitro. In this paper, we review the most recent advances on the mechanism of assembly for the founding member of the Fe–S cluster family, the [2Fe2S] cluster that is the building block of all other Fe–S clusters. The aim is to provide a survey of the mechanisms of iron and sulfur insertion in the scaffold proteins by examining how these processes are coordinated, how sulfide is produced and how the dinuclear [2Fe2S] cluster is formed, keeping in mind the question of the physiological relevance of the reconstituted systems. We also cover the latest outcomes on the functional role of the controversial frataxin protein in Fe–S cluster biosynthesis.
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Gervason S, Larkem D, Mansour AB, Botzanowski T, Müller CS, Pecqueur L, Le Pavec G, Delaunay-Moisan A, Brun O, Agramunt J, Grandas A, Fontecave M, Schünemann V, Cianférani S, Sizun C, Tolédano MB, D'Autréaux B. Physiologically relevant reconstitution of iron-sulfur cluster biosynthesis uncovers persulfide-processing functions of ferredoxin-2 and frataxin. Nat Commun 2019; 10:3566. [PMID: 31395877 PMCID: PMC6687725 DOI: 10.1038/s41467-019-11470-9] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 07/04/2019] [Indexed: 12/16/2022] Open
Abstract
Iron-sulfur (Fe-S) clusters are essential protein cofactors whose biosynthetic defects lead to severe diseases among which is Friedreich's ataxia caused by impaired expression of frataxin (FXN). Fe-S clusters are biosynthesized on the scaffold protein ISCU, with cysteine desulfurase NFS1 providing sulfur as persulfide and ferredoxin FDX2 supplying electrons, in a process stimulated by FXN but not clearly understood. Here, we report the breakdown of this process, made possible by removing a zinc ion in ISCU that hinders iron insertion and promotes non-physiological Fe-S cluster synthesis from free sulfide in vitro. By binding zinc-free ISCU, iron drives persulfide uptake from NFS1 and allows persulfide reduction into sulfide by FDX2, thereby coordinating sulfide production with its availability to generate Fe-S clusters. FXN stimulates the whole process by accelerating persulfide transfer. We propose that this reconstitution recapitulates physiological conditions which provides a model for Fe-S cluster biosynthesis, clarifies the roles of FDX2 and FXN and may help develop Friedreich's ataxia therapies.
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Affiliation(s)
- Sylvain Gervason
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Djabir Larkem
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Amir Ben Mansour
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Thomas Botzanowski
- Laboratoire de Spectrométrie de Masse BioOrganique, Université de Strasbourg, CNRS, IPHC UMR 7178, 67000, Strasbourg, France
| | - Christina S Müller
- Fachbreich Physik, Technische Universität Kaiserslautern, Erwin-Schrödinger-Str. 56, 67663, Kaiserslautern, Germany
| | - Ludovic Pecqueur
- Laboratoire de Chimie des Processus Biologiques, Collège de France, Sorbonne Université, CNRS UMR 8229, PSL Research University, 11 place Marcelin Berthelot, 75005, Paris, France
| | - Gwenaelle Le Pavec
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Agnès Delaunay-Moisan
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Omar Brun
- Departament de Química Orgànica i IBUB, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, E-08028, Barcelona, Spain
| | - Jordi Agramunt
- Departament de Química Orgànica i IBUB, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, E-08028, Barcelona, Spain
| | - Anna Grandas
- Departament de Química Orgànica i IBUB, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, E-08028, Barcelona, Spain
| | - Marc Fontecave
- Laboratoire de Chimie des Processus Biologiques, Collège de France, Sorbonne Université, CNRS UMR 8229, PSL Research University, 11 place Marcelin Berthelot, 75005, Paris, France
| | - Volker Schünemann
- Fachbreich Physik, Technische Universität Kaiserslautern, Erwin-Schrödinger-Str. 56, 67663, Kaiserslautern, Germany
| | - Sarah Cianférani
- Laboratoire de Spectrométrie de Masse BioOrganique, Université de Strasbourg, CNRS, IPHC UMR 7178, 67000, Strasbourg, France
| | - Christina Sizun
- Institut de Chimie des Substances Naturelles, CNRS, Université Paris Saclay, 91190, Gif-sur-Yvette, France
| | - Michel B Tolédano
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Benoit D'Autréaux
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France.
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Alsina D, Purroy R, Ros J, Tamarit J. Iron in Friedreich Ataxia: A Central Role in the Pathophysiology or an Epiphenomenon? Pharmaceuticals (Basel) 2018; 11:E89. [PMID: 30235822 PMCID: PMC6161073 DOI: 10.3390/ph11030089] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 09/15/2018] [Accepted: 09/17/2018] [Indexed: 12/16/2022] Open
Abstract
Friedreich ataxia is a neurodegenerative disease with an autosomal recessive inheritance. In most patients, the disease is caused by the presence of trinucleotide GAA expansions in the first intron of the frataxin gene. These expansions cause the decreased expression of this mitochondrial protein. Many evidences indicate that frataxin deficiency causes the deregulation of cellular iron homeostasis. In this review, we will discuss several hypotheses proposed for frataxin function, their caveats, and how they could provide an explanation for the deregulation of iron homeostasis found in frataxin-deficient cells. We will also focus on the potential mechanisms causing cellular dysfunction in Friedreich Ataxia and on the potential use of the iron chelator deferiprone as a therapeutic agent for this disease.
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Affiliation(s)
- David Alsina
- Departament de Ciències Mèdiques Bàsiques, IRBLleida, Universitat de Lleida, 25198 Lleida, Spain.
| | - Rosa Purroy
- Departament de Ciències Mèdiques Bàsiques, IRBLleida, Universitat de Lleida, 25198 Lleida, Spain.
| | - Joaquim Ros
- Departament de Ciències Mèdiques Bàsiques, IRBLleida, Universitat de Lleida, 25198 Lleida, Spain.
| | - Jordi Tamarit
- Departament de Ciències Mèdiques Bàsiques, IRBLleida, Universitat de Lleida, 25198 Lleida, Spain.
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Garcia-Serres R, Clémancey M, Latour JM, Blondin G. Contribution of Mössbauer spectroscopy to the investigation of Fe/S biogenesis. J Biol Inorg Chem 2018; 23:635-644. [PMID: 29350298 PMCID: PMC6006220 DOI: 10.1007/s00775-018-1534-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 01/04/2018] [Indexed: 10/27/2022]
Abstract
Fe/S cluster biogenesis involves a complex machinery comprising several mitochondrial and cytosolic proteins. Fe/S cluster biosynthesis is closely intertwined with iron trafficking in the cell. Defects in Fe/S cluster elaboration result in severe diseases such as Friedreich ataxia. Deciphering this machinery is a challenge for the scientific community. Because iron is a key player, 57Fe-Mössbauer spectroscopy is especially appropriate for the characterization of Fe species and monitoring the iron distribution. This minireview intends to illustrate how Mössbauer spectroscopy contributes to unravel steps in Fe/S cluster biogenesis. Studies were performed on isolated proteins that may be present in multiple protein complexes. Since a few decades, Mössbauer spectroscopy was also performed on whole cells or on isolated compartments such as mitochondria and vacuoles, affording an overview of the iron trafficking. This minireview aims at presenting selected applications of 57Fe-Mössbauer spectroscopy to Fe/S cluster biogenesis.
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Affiliation(s)
| | - Martin Clémancey
- Univ. Grenoble Alpes, CEA, CNRS, LCBM UMR 5249, pmb, 38000, Grenoble, France
| | - Jean-Marc Latour
- Univ. Grenoble Alpes, CEA, CNRS, LCBM UMR 5249, pmb, 38000, Grenoble, France
| | - Geneviève Blondin
- Univ. Grenoble Alpes, CEA, CNRS, LCBM UMR 5249, pmb, 38000, Grenoble, France. .,LCBM/pmb, CEA Bât C5, 17 Rue des Martyrs, 38054, Grenoble Cedex 9, France.
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10
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Gakh O, Ranatunga W, Galeano BK, Smith DS, Thompson JR, Isaya G. Defining the Architecture of the Core Machinery for the Assembly of Fe-S Clusters in Human Mitochondria. Methods Enzymol 2017; 595:107-160. [PMID: 28882199 DOI: 10.1016/bs.mie.2017.07.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Although Fe-S clusters may assemble spontaneously from elemental iron and sulfur in protein-free systems, the potential toxicity of free Fe2+, Fe3+, and S2- ions in aerobic environments underscores the requirement for specialized proteins to oversee the safe assembly of Fe-S clusters in living cells. Prokaryotes first developed multiprotein systems for Fe-S cluster assembly, from which mitochondria later derived their own system and became the main Fe-S cluster suppliers for eukaryotic cells. Early studies in yeast and human mitochondria indicated that Fe-S cluster assembly in eukaryotes is centered around highly conserved Fe-S proteins (human ISCU) that serve as scaffolds upon which new Fe-S clusters are assembled from (i) elemental sulfur, provided by a pyridoxal phosphate-dependent cysteine desulfurase (human NFS1) and its stabilizing-binding partner (human ISD11), and (ii) elemental iron, provided by an iron-binding protein of the frataxin family (human FXN). Further studies revealed that all of these proteins could form stable complexes that could reach molecular masses of megadaltons. However, the protein-protein interaction surfaces, catalytic mechanisms, and overall architecture of these macromolecular machines remained undefined for quite some time. The delay was due to difficulties inherent in reconstituting these very large multiprotein complexes in vitro or isolating them from cells in sufficient quantities to enable biochemical and structural studies. Here, we describe approaches we developed to reconstitute the human Fe-S cluster assembly machinery in Escherichia coli and to define its remarkable architecture.
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Affiliation(s)
| | | | - Belinda K Galeano
- Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN, United States
| | | | | | - Grazia Isaya
- Mayo Clinic, Rochester, MN, United States; Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN, United States; Mayo Clinic Children's Research Center, Rochester, MN, United States.
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11
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Han THL, Camadro JM, Santos R, Lesuisse E, El Hage Chahine JM, Ha-Duong NT. Mechanisms of iron and copper-frataxin interactions. Metallomics 2017; 9:1073-1085. [PMID: 28573291 DOI: 10.1039/c7mt00031f] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Frataxin is a mitochondrial protein whose deficiency is the cause of Friedreich's ataxia, a hereditary neurodegenerative disease. This protein plays a role in iron-sulfur cluster biosynthesis, protection against oxidative stress and iron metabolism. In an attempt to provide a better understanding of the role played by metals in its metabolic functions, the mechanisms of mitochondrial metal binding to frataxin in vitro have been investigated. A purified recombinant yeast frataxin homolog Yfh1 binds two Cu(ii) ions with a Kd1(CuII) of 1.3 × 10-7 M and a Kd2(CuII) of 3.1 × 10-4 M and a single Cu(i) ion with a higher affinity than for Cu(ii) (Kd(CuI) = 3.2 × 10-8 M). Mn(ii) forms two complexes with Yfh1 (Kd1(MnII) = 4.0 × 10-8 M; Kd2(MnII) = 4.0 × 10-7 M). Cu and Mn bind Yfh1 with higher affinities than Fe(ii). It is established for the first time that the mechanisms of the interaction of iron and copper with frataxin are comparable and involve three kinetic steps. The first step occurs in the 50-500 ms range and corresponds to a first metal uptake. This is followed by two other kinetic processes that are related to a second metal uptake and/or to a change in the conformation leading to thermodynamic equilibrium. Frataxin deficient Δyfh1 yeast cells exhibited a marked growth defect in the presence of exogenous Cu or Mn. Mitochondria from Δyfh1 strains also accumulated higher amounts of copper, suggesting a functional role of frataxin in vivo in copper homeostasis.
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Affiliation(s)
- T H L Han
- Université Paris Diderot, Sorbonne Paris Cité, "Interfaces, Traitements, Organisation et Dynamique des Systèmes", CNRS-UMR 7086, 15 rue Jean Antoine de Baïf, 75205 Paris Cedex 13, France.
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12
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Galeano BK, Ranatunga W, Gakh O, Smith DY, Thompson JR, Isaya G. Zinc and the iron donor frataxin regulate oligomerization of the scaffold protein to form new Fe-S cluster assembly centers. Metallomics 2017; 9:773-801. [PMID: 28548666 PMCID: PMC5552075 DOI: 10.1039/c7mt00089h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 05/02/2017] [Indexed: 02/06/2023]
Abstract
Early studies of the bacterial Fe-S cluster assembly system provided structural details for how the scaffold protein and the cysteine desulfurase interact. This work and additional work on the yeast and human systems elucidated a conserved mechanism for sulfur donation but did not provide any conclusive insights into the mechanism for iron delivery from the iron donor, frataxin, to the scaffold. We previously showed that oligomerization is a mechanism by which yeast frataxin (Yfh1) can promote assembly of the core machinery for Fe-S cluster synthesis both in vitro and in cells, in such a manner that the scaffold protein, Isu1, can bind to Yfh1 independent of the presence of the cysteine desulfurase, Nfs1. Here, in the absence of Yfh1, Isu1 was found to exist in two forms, one mostly monomeric with limited tendency to dimerize, and one with a strong propensity to oligomerize. Whereas the monomeric form is stabilized by zinc, the loss of zinc promotes formation of dimer and higher order oligomers. However, upon binding to oligomeric Yfh1, both forms take on a similar symmetrical trimeric configuration that places the Fe-S cluster coordinating residues of Isu1 in close proximity of iron-binding residues of Yfh1. This configuration is suitable for docking of Nfs1 in a manner that provides a structural context for coordinate iron and sulfur donation to the scaffold. Moreover, distinct structural features suggest that in physiological conditions the zinc-regulated abundance of monomeric vs. oligomeric Isu1 yields [Yfh1]·[Isu1] complexes with different Isu1 configurations that afford unique functional properties for Fe-S cluster assembly and delivery.
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Affiliation(s)
- B. K. Galeano
- Department of Pediatric & Adolescent Medicine , Mayo Clinic , Rochester , Minnesota , USA . ;
- Department of Biochemistry & Molecular Biology , Mayo Clinic , Rochester , Minnesota , USA
- Mayo Clinic Graduate School of Biomedical Sciences , Rochester , Minnesota , USA
| | - W. Ranatunga
- Department of Pediatric & Adolescent Medicine , Mayo Clinic , Rochester , Minnesota , USA . ;
- Mayo Clinic Children's Research Center , Rochester , Minnesota , USA
| | - O. Gakh
- Department of Pediatric & Adolescent Medicine , Mayo Clinic , Rochester , Minnesota , USA . ;
- Mayo Clinic Children's Research Center , Rochester , Minnesota , USA
| | - D. Y. Smith
- Department of Pediatric & Adolescent Medicine , Mayo Clinic , Rochester , Minnesota , USA . ;
- Mayo Clinic Children's Research Center , Rochester , Minnesota , USA
| | - J. R. Thompson
- Department of Biochemistry & Molecular Biology , Mayo Clinic , Rochester , Minnesota , USA
| | - G. Isaya
- Department of Pediatric & Adolescent Medicine , Mayo Clinic , Rochester , Minnesota , USA . ;
- Department of Biochemistry & Molecular Biology , Mayo Clinic , Rochester , Minnesota , USA
- Mayo Clinic Children's Research Center , Rochester , Minnesota , USA
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13
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Gakh O, Ranatunga W, Smith DY, Ahlgren EC, Al-Karadaghi S, Thompson JR, Isaya G. Architecture of the Human Mitochondrial Iron-Sulfur Cluster Assembly Machinery. J Biol Chem 2016; 291:21296-21321. [PMID: 27519411 PMCID: PMC5076535 DOI: 10.1074/jbc.m116.738542] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 08/10/2016] [Indexed: 11/06/2022] Open
Abstract
Fe-S clusters, essential cofactors needed for the activity of many different enzymes, are assembled by conserved protein machineries inside bacteria and mitochondria. As the architecture of the human machinery remains undefined, we co-expressed in Escherichia coli the following four proteins involved in the initial step of Fe-S cluster synthesis: FXN42-210 (iron donor); [NFS1]·[ISD11] (sulfur donor); and ISCU (scaffold upon which new clusters are assembled). We purified a stable, active complex consisting of all four proteins with 1:1:1:1 stoichiometry. Using negative staining transmission EM and single particle analysis, we obtained a three-dimensional model of the complex with ∼14 Å resolution. Molecular dynamics flexible fitting of protein structures docked into the EM map of the model revealed a [FXN42-210]24·[NFS1]24·[ISD11]24·[ISCU]24 complex, consistent with the measured 1:1:1:1 stoichiometry of its four components. The complex structure fulfills distance constraints obtained from chemical cross-linking of the complex at multiple recurring interfaces, involving hydrogen bonds, salt bridges, or hydrophobic interactions between conserved residues. The complex consists of a central roughly cubic [FXN42-210]24·[ISCU]24 sub-complex with one symmetric ISCU trimer bound on top of one symmetric FXN42-210 trimer at each of its eight vertices. Binding of 12 [NFS1]2·[ISD11]2 sub-complexes to the surface results in a globular macromolecule with a diameter of ∼15 nm and creates 24 Fe-S cluster assembly centers. The organization of each center recapitulates a previously proposed conserved mechanism for sulfur donation from NFS1 to ISCU and reveals, for the first time, a path for iron donation from FXN42-210 to ISCU.
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Affiliation(s)
- Oleksandr Gakh
- From the Departments of Pediatric and Adolescent Medicine and Biochemistry Molecular Biology, Mayo Clinic Children's Research Center, and
| | - Wasantha Ranatunga
- From the Departments of Pediatric and Adolescent Medicine and Biochemistry Molecular Biology, Mayo Clinic Children's Research Center, and
| | - Douglas Y Smith
- From the Departments of Pediatric and Adolescent Medicine and Biochemistry Molecular Biology, Mayo Clinic Children's Research Center, and
| | - Eva-Christina Ahlgren
- the Center for Molecular Protein Science, Institute for Chemistry and Chemical Engineering, Lund University, P. O. Box 124, SE-221 00 Lund, Sweden
| | - Salam Al-Karadaghi
- the Center for Molecular Protein Science, Institute for Chemistry and Chemical Engineering, Lund University, P. O. Box 124, SE-221 00 Lund, Sweden
| | - James R Thompson
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota 55905 and
| | - Grazia Isaya
- From the Departments of Pediatric and Adolescent Medicine and Biochemistry Molecular Biology, Mayo Clinic Children's Research Center, and
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14
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Chen K, Lin G, Haelterman NA, Ho TSY, Li T, Li Z, Duraine L, Graham BH, Jaiswal M, Yamamoto S, Rasband MN, Bellen HJ. Loss of Frataxin induces iron toxicity, sphingolipid synthesis, and Pdk1/Mef2 activation, leading to neurodegeneration. eLife 2016; 5:e16043. [PMID: 27343351 PMCID: PMC4956409 DOI: 10.7554/elife.16043] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 06/24/2016] [Indexed: 12/22/2022] Open
Abstract
Mutations in Frataxin (FXN) cause Friedreich's ataxia (FRDA), a recessive neurodegenerative disorder. Previous studies have proposed that loss of FXN causes mitochondrial dysfunction, which triggers elevated reactive oxygen species (ROS) and leads to the demise of neurons. Here we describe a ROS independent mechanism that contributes to neurodegeneration in fly FXN mutants. We show that loss of frataxin homolog (fh) in Drosophila leads to iron toxicity, which in turn induces sphingolipid synthesis and ectopically activates 3-phosphoinositide dependent protein kinase-1 (Pdk1) and myocyte enhancer factor-2 (Mef2). Dampening iron toxicity, inhibiting sphingolipid synthesis by Myriocin, or reducing Pdk1 or Mef2 levels, all effectively suppress neurodegeneration in fh mutants. Moreover, increasing dihydrosphingosine activates Mef2 activity through PDK1 in mammalian neuronal cell line suggesting that the mechanisms are evolutionarily conserved. Our results indicate that an iron/sphingolipid/Pdk1/Mef2 pathway may play a role in FRDA.
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Affiliation(s)
- Kuchuan Chen
- Program in Developmental Biology, Baylor College of Medicine, Houston, United States
| | - Guang Lin
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
| | - Nele A Haelterman
- Program in Developmental Biology, Baylor College of Medicine, Houston, United States
| | - Tammy Szu-Yu Ho
- Department of Neuroscience, Baylor College of Medicine, Houston, United States
| | - Tongchao Li
- Program in Developmental Biology, Baylor College of Medicine, Houston, United States
| | - Zhihong Li
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
| | - Lita Duraine
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, United States
| | - Brett H Graham
- Program in Developmental Biology, Baylor College of Medicine, Houston, United States
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
| | - Manish Jaiswal
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, United States
| | - Shinya Yamamoto
- Program in Developmental Biology, Baylor College of Medicine, Houston, United States
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, United States
| | - Matthew N Rasband
- Program in Developmental Biology, Baylor College of Medicine, Houston, United States
- Department of Neuroscience, Baylor College of Medicine, Houston, United States
| | - Hugo J Bellen
- Program in Developmental Biology, Baylor College of Medicine, Houston, United States
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
- Department of Neuroscience, Baylor College of Medicine, Houston, United States
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, United States
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, United States
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15
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Bhalla AD, Khodadadi-Jamayran A, Li Y, Lynch DR, Napierala M. Deep sequencing of mitochondrial genomes reveals increased mutation load in Friedreich's ataxia. Ann Clin Transl Neurol 2016; 3:523-36. [PMID: 27386501 PMCID: PMC4931717 DOI: 10.1002/acn3.322] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 05/12/2016] [Indexed: 12/02/2022] Open
Abstract
Objective Friedreich's ataxia (FRDA) is an autosomal recessive trinucleotide repeat expansion disorder caused by epigenetic silencing of the frataxin gene (FXN). Current research suggests that damage and variation of mitochondrial DNA (mtDNA) contribute to the molecular pathogenesis of FRDA. We sought to establish the extent of the mutation burden across the mitochondrial genome in FRDA cells and investigate the molecular mechanisms connecting FXN downregulation and the acquisition of mtDNA damage. Methods Damage and mutation load in mtDNA of a panel of FRDA and control fibroblasts were determined using qPCR and next‐generation MiSeq sequencing, respectively. The capacity of FRDA and control cells to repair oxidative lesions in their mtDNA was measured using a quantitative DNA damage assay. Comprehensive RNA sequencing gene expression analyses were conducted to assess the status of DNA repair and metabolism genes in FRDA cells. Results Acute or prolonged downregulation of FXN expression resulted in a significant increase in mtDNA damage that translated to a significant elevation of mutation load in mtDNA. The predominant mutations identified throughout the mtDNA were C>T, G>A transitions (P = 0.007). Low FXN expression reduced capacity to repair oxidative damage in mtDNA. Downregulation of FXN expression strongly correlated (r = 0.73) with decreased levels of base excision repair (BER) DNA glycosylase NTHL1. Interpretation Downregulation of FXN expression in FRDA cells elevates mtDNA damage, increases mutation load of the mitochondrial genome, and diminishes DNA repair capacity. Progressive accumulation of mtDNA mutations in vulnerable FRDA patient cells reduces mitochondrial fitness ultimately leading to cell death.
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Affiliation(s)
- Angela D Bhalla
- Department of Biochemistry and Molecular Genetics University of Alabama at Birmingham UAB Stem Cell Institute 1825 University Blvd. Birmingham Alabama 35294
| | - Alireza Khodadadi-Jamayran
- Department of Biochemistry and Molecular Genetics University of Alabama at Birmingham UAB Stem Cell Institute 1825 University Blvd. Birmingham Alabama 35294
| | - Yanjie Li
- Department of Biochemistry and Molecular Genetics University of Alabama at Birmingham UAB Stem Cell Institute 1825 University Blvd. Birmingham Alabama 35294
| | - David R Lynch
- Division of Neurology and Pediatrics Children's Hospital of Philadelphia Abramson Research Center Room 502 Philadelphia Pennsylvania 19104
| | - Marek Napierala
- Department of Biochemistry and Molecular Genetics University of Alabama at Birmingham UAB Stem Cell Institute 1825 University Blvd. Birmingham Alabama 35294; Department of Molecular Biomedicine Institute of Bioorganic Chemistry Polish Academy of Sciences Poznan 61-704 Poland
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16
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de Llanos R, Martínez-Garay CA, Fita-Torró J, Romero AM, Martínez-Pastor MT, Puig S. Soybean Ferritin Expression in Saccharomyces cerevisiae Modulates Iron Accumulation and Resistance to Elevated Iron Concentrations. Appl Environ Microbiol 2016; 82:3052-3060. [PMID: 26969708 PMCID: PMC4959083 DOI: 10.1128/aem.00305-16] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 03/08/2016] [Indexed: 02/06/2023] Open
Abstract
UNLABELLED Fungi, including the yeast Saccharomyces cerevisiae, lack ferritin and use vacuoles as iron storage organelles. This work explored how plant ferritin expression influenced baker's yeast iron metabolism. Soybean seed ferritin H1 (SFerH1) and SFerH2 genes were cloned and expressed in yeast cells. Both soybean ferritins assembled as multimeric complexes, which bound yeast intracellular iron in vivo and, consequently, induced the activation of the genes expressed during iron scarcity. Soybean ferritin protected yeast cells that lacked the Ccc1 vacuolar iron detoxification transporter from toxic iron levels by reducing cellular oxidation, thus allowing growth at high iron concentrations. Interestingly, when simultaneously expressed in ccc1Δ cells, SFerH1 and SFerH2 assembled as heteropolymers, which further increased iron resistance and reduced the oxidative stress produced by excess iron compared to ferritin homopolymer complexes. Finally, soybean ferritin expression led to increased iron accumulation in both wild-type and ccc1Δ yeast cells at certain environmental iron concentrations. IMPORTANCE Iron deficiency is a worldwide nutritional disorder to which women and children are especially vulnerable. A common strategy to combat iron deficiency consists of dietary supplementation with inorganic iron salts, whose bioavailability is very low. Iron-enriched yeasts and cereals are alternative strategies to diminish iron deficiency. Animals and plants possess large ferritin complexes that accumulate, detoxify, or buffer excess cellular iron. However, the yeast Saccharomyces cerevisiae lacks ferritin and uses vacuoles as iron storage organelles. Here, we explored how soybean ferritin expression influenced yeast iron metabolism, confirming that yeasts that express soybean seed ferritin could be explored as a novel strategy to increase dietary iron absorption.
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Affiliation(s)
- Rosa de Llanos
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, Paterna, Valencia, Spain
| | - Carlos Andrés Martínez-Garay
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, Paterna, Valencia, Spain
| | - Josep Fita-Torró
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, Paterna, Valencia, Spain
| | - Antonia María Romero
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, Paterna, Valencia, Spain
| | | | - Sergi Puig
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, Paterna, Valencia, Spain
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17
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Ranatunga W, Gakh O, Galeano BK, Smith DY, Söderberg CAG, Al-Karadaghi S, Thompson JR, Isaya G. Architecture of the Yeast Mitochondrial Iron-Sulfur Cluster Assembly Machinery: THE SUB-COMPLEX FORMED BY THE IRON DONOR, Yfh1 PROTEIN, AND THE SCAFFOLD, Isu1 PROTEIN. J Biol Chem 2016; 291:10378-98. [PMID: 26941001 PMCID: PMC4858984 DOI: 10.1074/jbc.m115.712414] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 02/26/2016] [Indexed: 12/18/2022] Open
Abstract
The biosynthesis of Fe-S clusters is a vital process involving the delivery of elemental iron and sulfur to scaffold proteins via molecular interactions that are still poorly defined. We reconstituted a stable, functional complex consisting of the iron donor, Yfh1 (yeast frataxin homologue 1), and the Fe-S cluster scaffold, Isu1, with 1:1 stoichiometry, [Yfh1]24·[Isu1]24 Using negative staining transmission EM and single particle analysis, we obtained a three-dimensional reconstruction of this complex at a resolution of ∼17 Å. In addition, via chemical cross-linking, limited proteolysis, and mass spectrometry, we identified protein-protein interaction surfaces within the complex. The data together reveal that [Yfh1]24·[Isu1]24 is a roughly cubic macromolecule consisting of one symmetric Isu1 trimer binding on top of one symmetric Yfh1 trimer at each of its eight vertices. Furthermore, molecular modeling suggests that two subunits of the cysteine desulfurase, Nfs1, may bind symmetrically on top of two adjacent Isu1 trimers in a manner that creates two putative [2Fe-2S] cluster assembly centers. In each center, conserved amino acids known to be involved in sulfur and iron donation by Nfs1 and Yfh1, respectively, are in close proximity to the Fe-S cluster-coordinating residues of Isu1. We suggest that this architecture is suitable to ensure concerted and protected transfer of potentially toxic iron and sulfur atoms to Isu1 during Fe-S cluster assembly.
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Affiliation(s)
- Wasantha Ranatunga
- From the Departments of Pediatric and Adolescent Medicine and Biochemistry and Molecular Biology, and the Mayo Clinic Children's Research Center, and
| | - Oleksandr Gakh
- From the Departments of Pediatric and Adolescent Medicine and Biochemistry and Molecular Biology, and the Mayo Clinic Children's Research Center, and
| | - Belinda K Galeano
- From the Departments of Pediatric and Adolescent Medicine and Biochemistry and Molecular Biology, and the Mayo Clinic Children's Research Center, and
| | - Douglas Y Smith
- From the Departments of Pediatric and Adolescent Medicine and Biochemistry and Molecular Biology, and the Mayo Clinic Children's Research Center, and
| | - Christopher A G Söderberg
- the Center for Molecular Protein Science, Institute for Chemistry and Chemical Engineering, Lund University, P. O. Box 124, SE-221 00 Lund, Sweden
| | - Salam Al-Karadaghi
- the Center for Molecular Protein Science, Institute for Chemistry and Chemical Engineering, Lund University, P. O. Box 124, SE-221 00 Lund, Sweden
| | - James R Thompson
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota 55905 and
| | - Grazia Isaya
- From the Departments of Pediatric and Adolescent Medicine and Biochemistry and Molecular Biology, and the Mayo Clinic Children's Research Center, and
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18
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Hayashi G, Cortopassi G. Oxidative stress in inherited mitochondrial diseases. Free Radic Biol Med 2015; 88:10-7. [PMID: 26073122 PMCID: PMC4593728 DOI: 10.1016/j.freeradbiomed.2015.05.039] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 04/10/2015] [Accepted: 05/26/2015] [Indexed: 12/22/2022]
Abstract
Mitochondria are a source of reactive oxygen species (ROS). Mitochondrial diseases are the result of inherited defects in mitochondrially expressed genes. One potential pathomechanism for mitochondrial disease is oxidative stress. Oxidative stress can occur as the result of increased ROS production or decreased ROS protection. The role of oxidative stress in the five most common inherited mitochondrial diseases, Friedreich ataxia, LHON, MELAS, MERRF, and Leigh syndrome (LS), is discussed. Published reports of oxidative stress involvement in the pathomechanisms of these five mitochondrial diseases are reviewed. The strongest evidence for an oxidative stress pathomechanism among the five diseases was for Friedreich ataxia. In addition, a meta-analysis was carried out to provide an unbiased evaluation of the role of oxidative stress in the five diseases, by searching for "oxidative stress" citation count frequency for each disease. Of the five most common mitochondrial diseases, the strongest support for oxidative stress is for Friedreich ataxia (6.42%), followed by LHON (2.45%), MELAS (2.18%), MERRF (1.71%), and LS (1.03%). The increased frequency of oxidative stress citations was significant relative to the mean of the total pool of five diseases (p<0.01) and the mean of the four non-Friedreich diseases (p<0.0001). Thus there is support for oxidative stress in all five most common mitochondrial diseases, but the strongest, significant support is for Friedreich ataxia.
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Affiliation(s)
- Genki Hayashi
- Department of Molecular Biosciences, University of California, Davis, CA 95616, USA
| | - Gino Cortopassi
- Department of Molecular Biosciences, University of California, Davis, CA 95616, USA.
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19
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Seguin A, Monnier V, Palandri A, Bihel F, Rera M, Schmitt M, Camadro JM, Tricoire H, Lesuisse E. A Yeast/Drosophila Screen to Identify New Compounds Overcoming Frataxin Deficiency. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:565140. [PMID: 26523199 PMCID: PMC4619980 DOI: 10.1155/2015/565140] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 12/26/2014] [Accepted: 01/06/2015] [Indexed: 11/17/2022]
Abstract
Friedreich's ataxia (FA) is a rare neurodegenerative disease which is very debilitating for the patients who progressively lose their autonomy. The lack of efficient therapeutic treatment of the disease strongly argues for urgent need to search for new active compounds that may stop the progression of the disease or prevent the appearance of the symptoms when the genetic defect is diagnosed early enough. In the present study, we used a yeast strain with a deletion of the frataxin homologue gene as a model of FA cells in a primary screen of two chemical libraries, a fraction of the French National Chemical Library (5500 compounds) and the Prestwick collection (880 compounds). We ran a secondary screen on Drosophila melanogaster flies expressing reduced levels of frataxin during larval development. Half of the compounds selected in yeast appeared to be active in flies in this developmental paradigm, and one of the two compounds with highest activities in this assay partially rescued the heart dilatation phenotype resulting from heart specific depletion of frataxin. The unique complementarity of these two frataxin-deficient models, unicellular and multicellular, appears to be very efficient to select new compounds with improved selectivity, bringing significant perspectives towards improvements in FA therapy.
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Affiliation(s)
- Alexandra Seguin
- “Mitochondries, Métaux et Stress Oxydant”, Institut Jacques Monod, UMR7592 CNRS-Université Paris Diderot, Sorbonne Paris Cité, 15 rue Hélène Brion, 75205 Paris Cedex 13, France
| | - Véronique Monnier
- Unité de Biologie Fonctionnelle et Adaptative (BFA), UMR8251 CNRS-Université Paris Diderot, Sorbonne Paris Cité, 4 rue M. A. Lagroua Weill Halle, 75205 Paris Cedex 13, France
| | - Amandine Palandri
- Unité de Biologie Fonctionnelle et Adaptative (BFA), UMR8251 CNRS-Université Paris Diderot, Sorbonne Paris Cité, 4 rue M. A. Lagroua Weill Halle, 75205 Paris Cedex 13, France
| | - Frédéric Bihel
- Laboratoire d'Innovation Thérapeutique, UMR7200 CNRS-Université de Strasbourg, Faculté de Pharmacie, 74 route du Rhin, BP 60024, 67401 Illkirch Cedex, France
| | - Michael Rera
- Unité de Biologie Fonctionnelle et Adaptative (BFA), UMR8251 CNRS-Université Paris Diderot, Sorbonne Paris Cité, 4 rue M. A. Lagroua Weill Halle, 75205 Paris Cedex 13, France
| | - Martine Schmitt
- Laboratoire d'Innovation Thérapeutique, UMR7200 CNRS-Université de Strasbourg, Faculté de Pharmacie, 74 route du Rhin, BP 60024, 67401 Illkirch Cedex, France
| | - Jean-Michel Camadro
- “Mitochondries, Métaux et Stress Oxydant”, Institut Jacques Monod, UMR7592 CNRS-Université Paris Diderot, Sorbonne Paris Cité, 15 rue Hélène Brion, 75205 Paris Cedex 13, France
| | - Hervé Tricoire
- Unité de Biologie Fonctionnelle et Adaptative (BFA), UMR8251 CNRS-Université Paris Diderot, Sorbonne Paris Cité, 4 rue M. A. Lagroua Weill Halle, 75205 Paris Cedex 13, France
| | - Emmanuel Lesuisse
- “Mitochondries, Métaux et Stress Oxydant”, Institut Jacques Monod, UMR7592 CNRS-Université Paris Diderot, Sorbonne Paris Cité, 15 rue Hélène Brion, 75205 Paris Cedex 13, France
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20
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Bresgen N, Eckl PM. Oxidative stress and the homeodynamics of iron metabolism. Biomolecules 2015; 5:808-47. [PMID: 25970586 PMCID: PMC4496698 DOI: 10.3390/biom5020808] [Citation(s) in RCA: 148] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 04/21/2015] [Accepted: 04/22/2015] [Indexed: 12/12/2022] Open
Abstract
Iron and oxygen share a delicate partnership since both are indispensable for survival, but if the partnership becomes inadequate, this may rapidly terminate life. Virtually all cell components are directly or indirectly affected by cellular iron metabolism, which represents a complex, redox-based machinery that is controlled by, and essential to, metabolic requirements. Under conditions of increased oxidative stress—i.e., enhanced formation of reactive oxygen species (ROS)—however, this machinery may turn into a potential threat, the continued requirement for iron promoting adverse reactions such as the iron/H2O2-based formation of hydroxyl radicals, which exacerbate the initial pro-oxidant condition. This review will discuss the multifaceted homeodynamics of cellular iron management under normal conditions as well as in the context of oxidative stress.
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Affiliation(s)
- Nikolaus Bresgen
- Department of Cell Biology, University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria.
| | - Peter M Eckl
- Department of Cell Biology, University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria.
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21
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Parent A, Elduque X, Cornu D, Belot L, Le Caer JP, Grandas A, Toledano MB, D'Autréaux B. Mammalian frataxin directly enhances sulfur transfer of NFS1 persulfide to both ISCU and free thiols. Nat Commun 2015; 6:5686. [PMID: 25597503 DOI: 10.1038/ncomms6686] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2014] [Accepted: 10/28/2014] [Indexed: 02/08/2023] Open
Abstract
Friedreich's ataxia is a severe neurodegenerative disease caused by the decreased expression of frataxin, a mitochondrial protein that stimulates iron-sulfur (Fe-S) cluster biogenesis. In mammals, the primary steps of Fe-S cluster assembly are performed by the NFS1-ISD11-ISCU complex via the formation of a persulfide intermediate on NFS1. Here we show that frataxin modulates the reactivity of NFS1 persulfide with thiols. We use maleimide-peptide compounds along with mass spectrometry to probe cysteine-persulfide in NFS1 and ISCU. Our data reveal that in the presence of ISCU, frataxin enhances the rate of two similar reactions on NFS1 persulfide: sulfur transfer to ISCU leading to the accumulation of a persulfide on the cysteine C104 of ISCU, and sulfur transfer to small thiols such as DTT, L-cysteine and GSH leading to persulfuration of these thiols and ultimately sulfide release. These data raise important questions on the physiological mechanism of Fe-S cluster assembly and point to a unique function of frataxin as an enhancer of sulfur transfer within the NFS1-ISD11-ISCU complex.
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Affiliation(s)
- Aubérie Parent
- Institut de Chimie des Substances Naturelles, UPR2301, Centre de Recherche de Gif, Centre National de la Recherche Scientifique, 1 avenue de la terrasse, 91191 Gif Sur Yvette, France
| | - Xavier Elduque
- Departament de Química Orgànica i IBUB, Facultat de Química, Universitat de Barcelona, Marti i Franques 1-11, E-08028 Barcelona, Spain
| | - David Cornu
- Plateforme IMAGIF, Centre de Recherche de Gif, Centre National de la Recherche Scientifique, 1 avenue de le terrasse, 91191 Gif Sur Yvette, France
| | - Laura Belot
- Institut de Chimie des Substances Naturelles, UPR2301, Centre de Recherche de Gif, Centre National de la Recherche Scientifique, 1 avenue de la terrasse, 91191 Gif Sur Yvette, France
| | - Jean-Pierre Le Caer
- Institut de Chimie des Substances Naturelles, UPR2301, Centre de Recherche de Gif, Centre National de la Recherche Scientifique, 1 avenue de la terrasse, 91191 Gif Sur Yvette, France
| | - Anna Grandas
- Departament de Química Orgànica i IBUB, Facultat de Química, Universitat de Barcelona, Marti i Franques 1-11, E-08028 Barcelona, Spain
| | - Michel B Toledano
- Laboratoire Stress Oxydant et Cancer, Service de Biologie Intégrative et de Génétique Moléculaire, Institut de Biologie et de Technologie de Saclay, Commissariat à l'Energie Atomique et aux Energies Alternatives, F-91191 Gif Sur Yvette, France
| | - Benoit D'Autréaux
- Institut de Chimie des Substances Naturelles, UPR2301, Centre de Recherche de Gif, Centre National de la Recherche Scientifique, 1 avenue de la terrasse, 91191 Gif Sur Yvette, France
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22
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Martelli A, Puccio H. Dysregulation of cellular iron metabolism in Friedreich ataxia: from primary iron-sulfur cluster deficit to mitochondrial iron accumulation. Front Pharmacol 2014; 5:130. [PMID: 24917819 PMCID: PMC4042101 DOI: 10.3389/fphar.2014.00130] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 05/14/2014] [Indexed: 01/25/2023] Open
Abstract
Friedreich ataxia (FRDA) is the most common recessive ataxia in the Caucasian population and is characterized by a mixed spinocerebellar and sensory ataxia frequently associating cardiomyopathy. The disease results from decreased expression of the FXN gene coding for the mitochondrial protein frataxin. Early histological and biochemical study of the pathophysiology in patient's samples revealed that dysregulation of iron metabolism is a key feature of the disease, mainly characterized by mitochondrial iron accumulation and by decreased activity of iron-sulfur cluster enzymes. In the recent past years, considerable progress in understanding the function of frataxin has been provided through cellular and biochemical approaches, pointing to the primary role of frataxin in iron-sulfur cluster biogenesis. However, why and how the impact of frataxin deficiency on this essential biosynthetic pathway leads to mitochondrial iron accumulation is still poorly understood. Herein, we review data on both the primary function of frataxin and the nature of the iron metabolism dysregulation in FRDA. To date, the pathophysiological implication of the mitochondrial iron overload in FRDA remains to be clarified.
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Affiliation(s)
- Alain Martelli
- Department of Translational Medecine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire Illkirch, France ; INSERM, U596 Illkirch, France ; CNRS, UMR7104 Illkirch, France ; Université de Strasbourg Strasbourg, France ; Chaire de Génétique Humaine, Collège de France Illkirch, France
| | - Hélène Puccio
- Department of Translational Medecine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire Illkirch, France ; INSERM, U596 Illkirch, France ; CNRS, UMR7104 Illkirch, France ; Université de Strasbourg Strasbourg, France ; Chaire de Génétique Humaine, Collège de France Illkirch, France
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23
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Anzovino A, Lane DJR, Huang MLH, Richardson DR. Fixing frataxin: 'ironing out' the metabolic defect in Friedreich's ataxia. Br J Pharmacol 2014; 171:2174-90. [PMID: 24138602 PMCID: PMC3976629 DOI: 10.1111/bph.12470] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 09/17/2013] [Accepted: 10/07/2013] [Indexed: 12/14/2022] Open
Abstract
The metabolically active and redox-active mitochondrion appears to play a major role in the cellular metabolism of the transition metal, iron. Frataxin, a mitochondrial matrix protein, has been identified as playing a key role in the iron metabolism of this organelle due to its iron-binding properties and is known to be essential for iron-sulphur cluster formation. However, the precise function of frataxin remains elusive. The decrease in frataxin expression, as seen in the inherited disorder Friedreich's ataxia, markedly alters cellular and mitochondrial iron metabolism in both the mitochondrion and the cell. The resulting dysregulation of iron trafficking damages affects tissues leading to neuro- and cardiodegeneration. This disease underscores the importance of iron homeostasis in the redox-active environment of the mitochondrion and the molecular players involved. Unravelling the mechanisms of altered iron metabolism in Friedreich's ataxia will help elucidate a biochemical function for frataxin. Consequently, this will enable the development of more effective and rationally designed treatments. This review will focus on the emerging function of frataxin in relation to the observed alterations in mitochondrial iron metabolism in Friedreich's ataxia. Tissue-specific alterations due to frataxin loss will also be discussed, as well as current and emerging therapeutic strategies.
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Affiliation(s)
- A Anzovino
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, University of SydneySydney, NSW, Australia
| | - D J R Lane
- Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, University of SydneySydney, NSW, Australia
| | | | - D R Richardson
- Correspondence Professor D R Richardson, Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, University of Sydney, Sydney, NSW 2006, Australia. E-mail:
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24
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Park J, McCormick SP, Chakrabarti M, Lindahl PA. Insights into the iron-ome and manganese-ome of Δmtm1 Saccharomyces cerevisiae mitochondria. Metallomics 2013; 5:656-72. [PMID: 23598994 DOI: 10.1039/c3mt00041a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Biophysical spectroscopies and LC-ICP-MS were used to evaluate the iron-ome and manganese-ome of mitochondria from Δmtm1 yeast cells. Deleting the mitochondrial carrier gene MTM1 causes Fe to accumulate in mitochondria and Mn superoxide dismutase (SOD2) activity to decline. One explanation for this is that some accumulated Fe misincorporates into apo-Sod2p. Mössbauer spectroscopy revealed that most of the accumulated Fe was Fe(III) nanoparticles which are unlikely to misincorporate into apo-Sod2p. Under anaerobic conditions, Fe did not accumulate yet SOD2 activity remained low, suggesting that the two phenomena are independent. Mn concentrations were two-fold higher in Δmtm1 mitochondria than in WT mitochondria. Soluble extracts from such samples were subjected to size-exclusion LC and fractions were analyzed with an on-line ICP-MS. Two major Mn peaks were observed, one due to MnSod2p and the other to a Mn species with a mass of 2-3 kDa (called Mn2-3). Mn2-3 may deliver Mn into apo-Sod2p. Most Mn in WT mitochondria was associated with MnSod2p, whereas most Mn in Δmtm1 mitochondria was associated with Mn2-3. The [Mn2-3] increased in cells grown on high MnCl2 while the MnSod2p concentration remained unchanged. Corresponding Fe traces showed numerous peaks, including a complex of ~3 kDa which may be the form of Fe that misincorporates, and an Fe peak with the molecular mass of Sod2p that may correspond to FeSod2p. The intensity of this peak suggests that deleting MTM1 probably diminishes SOD2 activity by some means other than Fe misincorporation. A portion of Sod2p in Δmtm1 mitochondria might be unfolded or immature. Mtm1p may import a species required for apo-Sod2p maturation, activity or stability.
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Affiliation(s)
- Jinkyu Park
- Texas A&M University, Department of Chemistry, College Station, TX 77843, USA
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25
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Giardia intestinalis incorporates heme into cytosolic cytochrome b₅. EUKARYOTIC CELL 2013; 13:231-9. [PMID: 24297440 DOI: 10.1128/ec.00200-13] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The anaerobic intestinal pathogen Giardia intestinalis does not possess enzymes for heme synthesis, and it also lacks the typical set of hemoproteins that are involved in mitochondrial respiration and cellular oxygen stress management. Nevertheless, G. intestinalis may require heme for the function of particular hemoproteins, such as cytochrome b5 (cytb5). We have analyzed the sequences of eukaryotic cytb5 proteins and identified three distinct cytb5 groups: group I, which consists of C-tail membrane-anchored cytb5 proteins; group II, which includes soluble cytb5 proteins; and group III, which comprises the fungal cytb5 proteins. The majority of eukaryotes possess both group I and II cytb5 proteins, whereas three Giardia paralogs belong to group II. We have identified a fourth Giardia cytb5 paralog (gCYTb5-IV) that is rather divergent and possesses an unusual 134-residue N-terminal extension. Recombinant Giardia cytb5 proteins, including gCYTb5-IV, were expressed in Escherichia coli and exhibited characteristic UV-visible spectra that corresponded to heme-loaded cytb5 proteins. The expression of the recombinant gCYTb5-IV in G. intestinalis resulted in the increased import of extracellular heme and its incorporation into the protein, whereas this effect was not observed when gCYTb5-IV containing a mutated heme-binding site was expressed. The electrons for Giardia cytb5 proteins may be provided by the NADPH-dependent Tah18-like oxidoreductase GiOR-1. Therefore, GiOR-1 and cytb5 may constitute a novel redox system in G. intestinalis. To our knowledge, G. intestinalis is the first anaerobic eukaryote in which the presence of heme has been directly demonstrated.
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26
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Jhurry ND, Chakrabarti M, McCormick SP, Gohil VM, Lindahl PA. Mössbauer study and modeling of iron import and trafficking in human jurkat cells. Biochemistry 2013; 52:7926-42. [PMID: 24180611 DOI: 10.1021/bi401015t] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The Fe content of Jurkat cells grown on transferrin-bound iron (TBI) and Fe(III) citrate (FC) was characterized using Mössbauer, electron paramagnetic resonance, and UV-vis spectroscopies, as well as electron and inductively coupled plasma mass spectrometry. Isolated mitochondria were similarly characterized. Fe-limited cells contained ~100 μM essential Fe, mainly as mitochondrial Fe and nonmitochondrial non-heme high-spin Fe(II). Cells replete with Fe also contained ferritin-bound Fe and Fe(III) oxyhydroxide nanoparticles. Only 400 ± 100 Fe ions were loaded per ferritin complex, regardless of the growth medium Fe concentration. Ferritin regulation thus appears to be more complex than is commonly assumed. The magnetic and structural properties of Jurkat nanoparticles differed from those of yeast mitochondria. They were smaller and may be located in the cytosol. The extent of nanoparticle formation scaled nonlinearly with the concentration of Fe in the medium. Nanoparticle formation was not strongly correlated with reactive oxygen species (ROS) damage. Cells could utilize nanoparticle Fe, converting such aggregates into essential Fe forms. Cells grown on galactose rather than glucose respired faster, grew slower, exhibited more ROS damage, and generally contained more nanoparticles. Cells grown with TBI rather than FC contained less Fe overall, more ferritin, and fewer nanoparticles. Cells in which the level of transferrin receptor expression was increased contained more ferritin Fe. Frataxin-deficient cells contained more nanoparticles than comparable wild-type cells. Data were analyzed by a chemically based mathematical model. Although simple, it captured essential features of Fe import, trafficking, and regulation. TBI import was highly regulated, but FC import was not. Nanoparticle formation was not regulated, but the rate was third-order in cytosolic Fe.
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Affiliation(s)
- Nema D Jhurry
- Department of Biochemistry and Biophysics, Texas A&M University , College Station, Texas 77843-2128, United States
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27
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Vaubel RA, Isaya G. Iron-sulfur cluster synthesis, iron homeostasis and oxidative stress in Friedreich ataxia. Mol Cell Neurosci 2013; 55:50-61. [PMID: 22917739 PMCID: PMC3530001 DOI: 10.1016/j.mcn.2012.08.003] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Revised: 08/01/2012] [Accepted: 08/05/2012] [Indexed: 12/21/2022] Open
Abstract
Friedreich ataxia (FRDA) is an autosomal recessive, multi-systemic degenerative disease that results from reduced synthesis of the mitochondrial protein frataxin. Frataxin has been intensely studied since its deficiency was linked to FRDA in 1996. The defining properties of frataxin - (i) the ability to bind iron, (ii) the ability to interact with, and donate iron to, other iron-binding proteins, and (iii) the ability to oligomerize, store iron and control iron redox chemistry - have been extensively characterized with different frataxin orthologs and their interacting protein partners. This very large body of biochemical and structural data [reviewed in (Bencze et al., 2006)] supports equally extensive biological evidence that frataxin is critical for mitochondrial iron metabolism and overall cellular iron homeostasis and antioxidant protection [reviewed in (Wilson, 2006)]. However, the precise biological role of frataxin remains a matter of debate. Here, we review seminal and recent data that strongly link frataxin to the synthesis of iron-sulfur cluster cofactors (ISC), as well as controversial data that nevertheless link frataxin to additional iron-related processes. Finally, we discuss how defects in ISC synthesis could be a major (although likely not unique) contributor to the pathophysiology of FRDA via (i) loss of ISC-dependent enzymes, (ii) mitochondrial and cellular iron dysregulation, and (iii) enhanced iron-mediated oxidative stress. This article is part of a Special Issue entitled 'Mitochondrial function and dysfunction in neurodegeneration'.
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Affiliation(s)
- Rachael A Vaubel
- Department of Pediatric & Adolescent Medicine and the Mayo Clinic Children's Center, Mayo Clinic, Rochester, MN 55905, USA
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28
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Jellinger KA. The relevance of metals in the pathophysiology of neurodegeneration, pathological considerations. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2013; 110:1-47. [PMID: 24209432 DOI: 10.1016/b978-0-12-410502-7.00002-8] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Neurodegenerative disorders are featured by a variety of pathological conditions that share similar critical processes, such as oxidative stress, free radical activity, proteinaceous aggregations, mitochondrial dysfunctions, and energy failure. They are mediated or triggered by an imbalance of metal ions leading to changes of critical biological systems and initiating a cascade of events finally leading to neurodegeneration and cell death. Their causes are multifactorial, and although the source of the shift in oxidative homeostasis is still unclear, current evidence points to changes in the balance of redox transition metals, especially iron, copper, and other trace metals. They are present at elevated levels in Alzheimer disease, Parkinson disease, multisystem atrophy, etc., while in other neurodegenerative disorders, copper, zinc, aluminum, and manganese are involved. This chapter will review the recent advances of the role of metals in the pathogenesis and pathophysiology of major neurodegenerative diseases and discuss the use of chelating agents as potential therapies for metal-related disorders.
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29
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Sutak R, Botebol H, Blaiseau PL, Léger T, Bouget FY, Camadro JM, Lesuisse E. A comparative study of iron uptake mechanisms in marine microalgae: iron binding at the cell surface is a critical step. PLANT PHYSIOLOGY 2012; 160:2271-84. [PMID: 23033141 PMCID: PMC3510147 DOI: 10.1104/pp.112.204156] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
We investigated iron uptake mechanisms in five marine microalgae from different ecologically important phyla: the diatoms Phaeodactylum tricornutum and Thalassiosira pseudonana, the prasinophyceae Ostreococcus tauri and Micromonas pusilla, and the coccolithophore Emiliania huxleyi. Among these species, only the two diatoms were clearly able to reduce iron, via an inducible (P. tricornutum) or constitutive (T. pseudonana) ferrireductase system displaying characteristics similar to the yeast (Saccharomyces cerevisiae) flavohemoproteins proteins. Iron uptake mechanisms probably involve very different components according to the species, but the species we studied shared common features. Regardless of the presence and/or induction of a ferrireductase system, all the species were able to take up both ferric and ferrous iron, and iron reduction was not a prerequisite for uptake. Iron uptake decreased with increasing the affinity constants of iron-ligand complexes and with increasing ligand-iron ratios. Therefore, at least one step of the iron uptake mechanism involves a thermodynamically controlled process. Another step escapes to simple thermodynamic rules and involves specific and strong binding of ferric as well as ferrous iron at the cell surface before uptake of iron. Binding was paradoxically increased in iron-rich conditions, whereas uptake per se was induced in all species only after prolonged iron deprivation. We sought cell proteins loaded with iron following iron uptake. One such protein in O. tauri may be ferritin, and in P. tricornutum, Isip1 may be involved. We conclude that the species we studied have uptake systems for both ferric and ferrous iron, both involving specific iron binding at the cell surface.
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30
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Sutak R, Seguin A, Garcia-Serres R, Oddou JL, Dancis A, Tachezy J, Latour JM, Camadro JM, Lesuisse E. Human mitochondrial ferritin improves respiratory function in yeast mutants deficient in iron-sulfur cluster biogenesis, but is not a functional homologue of yeast frataxin. Microbiologyopen 2012; 1:95-104. [PMID: 22950017 PMCID: PMC3426411 DOI: 10.1002/mbo3.18] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 01/31/2012] [Accepted: 02/06/2012] [Indexed: 12/25/2022] Open
Abstract
We overexpressed human mitochondrial ferritin in frataxin-deficient yeast cells (Δyfh1), but also in another mutant affected in [Fe-S] assembly (Δggc1). Ferritin was correctly processed and expressed in the mitochondria of these cells, but the fraction of total mitochondrial iron bound to ferritin was very low, and most of the iron remained in the form of insoluble particles of ferric phosphate in these mitochondria, as evidenced by gel filtration analysis of the mitochondrial matrix (fast protein liquid chromatography [FPLC]) and by Mössbauer spectroscopy. Mutant cells in which ferritin was overexpressed still accumulated iron in the mitochondria and remained deficient in [Fe-S] assembly, suggesting that human mitochondrial ferritin is not a functional homologue of yeast frataxin. However, the respiratory function was improved in these mutants, which correlates with an improvement of cytochrome and heme synthesis. Overexpression of mitochondrial ferritin in [Fe-S] mutants resulted in the appearance of a small pool of high-spin ferrous iron in the mitochondria, which was probably responsible for the improvement of heme synthesis and of the respiratory function in these mutants.
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Affiliation(s)
- Robert Sutak
- Department of Parasitology, Faculty of Science, Charles University in PragueVinicna 7, 128 44 Prague, Czech Republic
| | - Alexandra Seguin
- Laboratoire Mitochondries, Métaux et Stress oxydant, Institut Jacques Monod, CNRS-Université Paris DiderotFrance
| | - Ricardo Garcia-Serres
- CEA, iRTSV, LCBM, 38054 Grenoble Cedex 9, France; CNRS, UMR5249, Grenoble, France, Université Joseph Fourier38054 Grenoble Cedex 9, France
| | - Jean-Louis Oddou
- CEA, iRTSV, LCBM, 38054 Grenoble Cedex 9, France; CNRS, UMR5249, Grenoble, France, Université Joseph Fourier38054 Grenoble Cedex 9, France
| | - Andrew Dancis
- University of Pennsylvania,, Department of Medicine, Division of Hematology/OncologyBRBII Room 731, 431 Curie Blvd, Philadelphia, PA 19104
| | - Jan Tachezy
- Department of Parasitology, Faculty of Science, Charles University in PragueVinicna 7, 128 44 Prague, Czech Republic
| | - Jean-Marc Latour
- CEA, iRTSV, LCBM, 38054 Grenoble Cedex 9, France; CNRS, UMR5249, Grenoble, France, Université Joseph Fourier38054 Grenoble Cedex 9, France
| | - Jean-Michel Camadro
- Laboratoire Mitochondries, Métaux et Stress oxydant, Institut Jacques Monod, CNRS-Université Paris DiderotFrance
| | - Emmanuel Lesuisse
- Laboratoire Mitochondries, Métaux et Stress oxydant, Institut Jacques Monod, CNRS-Université Paris DiderotFrance
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31
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Jhurry ND, Chakrabarti M, McCormick SP, Holmes-Hampton GP, Lindahl PA. Biophysical investigation of the ironome of human jurkat cells and mitochondria. Biochemistry 2012; 51:5276-84. [PMID: 22726227 DOI: 10.1021/bi300382d] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The speciation of iron in intact human Jurkat leukemic cells and their isolated mitochondria was assessed using biophysical methods. Large-scale cultures were grown in medium enriched with (57)Fe citrate. Mitochondria were isolated anaerobically to prevent oxidation of iron centers. 5 K Mössbauer spectra of cells were dominated by a sextet due to ferritin. They also exhibited an intense central quadrupole doublet due to S = 0 [Fe(4)S(4)](2+) clusters and low-spin (LS) Fe(II) heme centers. Spectra of isolated mitochondria were largely devoid of ferritin but contained the central doublet and features arising from what appear to be Fe(III) oxyhydroxide (phosphate) nanoparticles. Spectra from both cells and mitochondria contained a low-intensity doublet from non-heme high-spin (NHHS) Fe(II) species. A portion of these species may constitute the "labile iron pool" (LIP) proposed in cellular Fe trafficking. Such species might engage in Fenton chemistry to generate reactive oxygen species. Electron paramagnetic resonance spectra of cells and mitochondria exhibited signals from reduced Fe/S clusters, and HS Fe(III) heme and non-heme species. The basal heme redox state of mitochondria within cells was reduced; this redox poise was unaltered during the anaerobic isolation of the organelle. Contributions from heme a, b, and c centers were quantified using electronic absorption spectroscopy. Metal concentrations in cells and mitochondria were measured using inductively coupled plasma mass spectrometry. Results were collectively assessed to estimate the concentrations of various Fe-containing species in mitochondria and whole cells - the first "ironome" profile of a human cell.
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Affiliation(s)
- Nema D Jhurry
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843-2128, USA
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32
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Bayot A, Santos R, Camadro JM, Rustin P. Friedreich's ataxia: the vicious circle hypothesis revisited. BMC Med 2011; 9:112. [PMID: 21985033 PMCID: PMC3198887 DOI: 10.1186/1741-7015-9-112] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 10/11/2011] [Indexed: 12/18/2022] Open
Abstract
Friedreich's ataxia, the most frequent progressive autosomal recessive disorder involving the central and peripheral nervous systems, is mostly associated with unstable expansion of GAA trinucleotide repeats in the first intron of the FXN gene, which encodes the mitochondrial frataxin protein. Since FXN was shown to be involved in Friedreich's ataxia in the late 1990s, the consequence of frataxin loss of function has generated vigorous debate. Very early on we suggested a unifying hypothesis according to which frataxin deficiency leads to a vicious circle of faulty iron handling, impaired iron-sulphur cluster synthesis and increased oxygen radical production. However, data from cell and animal models now indicate that iron accumulation is an inconsistent and late event and that frataxin deficiency does not always impair the activity of iron-sulphur cluster-containing proteins. In contrast, frataxin deficiency appears to be consistently associated with increased sensitivity to reactive oxygen species as opposed to increased oxygen radical production. By compiling the findings of fundamental research and clinical observations we defend here the opinion that the very first consequence of frataxin depletion is indeed an abnormal oxidative status which initiates the pathogenic mechanism underlying Friedreich's ataxia.
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Affiliation(s)
- Aurélien Bayot
- Inserm, U676, Physiopathology and Therapy of Mitochondrial Diseases Laboratory, CHU - Hôpital Robert Debré, 48, boulevard Sérurier, F-75019 Paris, France
- Faculté de médecine Denis Diderot, Université Paris-Diderot, IFR02, 16, rue Henri Huchard, F-75018, Paris, France
| | - Renata Santos
- Institut Jacques Monod (UMR 7592 CNRS-Université Paris-Diderot), Mitochondria, Metals and Oxidative Stress Laboratory, Bâtiment Buffon - 15, rue Hélène Brion, F-75205 Paris, Cedex 13, France
| | - Jean-Michel Camadro
- Institut Jacques Monod (UMR 7592 CNRS-Université Paris-Diderot), Mitochondria, Metals and Oxidative Stress Laboratory, Bâtiment Buffon - 15, rue Hélène Brion, F-75205 Paris, Cedex 13, France
| | - Pierre Rustin
- Inserm, U676, Physiopathology and Therapy of Mitochondrial Diseases Laboratory, CHU - Hôpital Robert Debré, 48, boulevard Sérurier, F-75019 Paris, France
- Faculté de médecine Denis Diderot, Université Paris-Diderot, IFR02, 16, rue Henri Huchard, F-75018, Paris, France
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33
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Seguin A, Santos R, Pain D, Dancis A, Camadro JM, Lesuisse E. Co-precipitation of phosphate and iron limits mitochondrial phosphate availability in Saccharomyces cerevisiae lacking the yeast frataxin homologue (YFH1). J Biol Chem 2011; 286:6071-9. [PMID: 21189251 PMCID: PMC3057820 DOI: 10.1074/jbc.m110.163253] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Revised: 12/21/2010] [Indexed: 01/29/2023] Open
Abstract
Saccharomyces cerevisiae cells lacking the yeast frataxin homologue (Δyfh1) accumulate iron in the mitochondria in the form of nanoparticles of ferric phosphate. The phosphate content of Δyfh1 mitochondria was higher than that of wild-type mitochondria, but the proportion of mitochondrial phosphate that was soluble was much lower in Δyfh1 cells. The rates of phosphate and iron uptake in vitro by isolated mitochondria were higher for Δyfh1 than wild-type mitochondria, and a significant proportion of the phosphate and iron rapidly became insoluble in the mitochondrial matrix, suggesting co-precipitation of these species after oxidation of iron by oxygen. Increasing the amount of phosphate in the medium decreased the amount of iron accumulated by Δyfh1 cells and improved their growth in an iron-dependent manner, and this effect was mostly transcriptional. Overexpressing the major mitochondrial phosphate carrier, MIR1, slightly increased the concentration of soluble mitochondrial phosphate and significantly improved various mitochondrial functions (cytochromes, [Fe-S] clusters, and respiration) in Δyfh1 cells. We conclude that in Δyfh1 cells, soluble phosphate is limiting, due to its co-precipitation with iron.
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Affiliation(s)
- Alexandra Seguin
- From the Institut Jacques Monod, CNRS-University Paris Diderot 75205 Paris cedex 13, France
| | - Renata Santos
- From the Institut Jacques Monod, CNRS-University Paris Diderot 75205 Paris cedex 13, France
| | - Debkumar Pain
- the Department of Pharmacology and Physiology, University of Medicine and Dentistry of New Jersey, Newark, New Jersey 07103, and
| | - Andrew Dancis
- the Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Jean-Michel Camadro
- From the Institut Jacques Monod, CNRS-University Paris Diderot 75205 Paris cedex 13, France
| | - Emmanuel Lesuisse
- From the Institut Jacques Monod, CNRS-University Paris Diderot 75205 Paris cedex 13, France
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34
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Lindahl PA, Holmes-Hampton GP. Biophysical probes of iron metabolism in cells and organelles. Curr Opin Chem Biol 2011; 15:342-6. [PMID: 21282072 DOI: 10.1016/j.cbpa.2011.01.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Revised: 01/04/2011] [Accepted: 01/05/2011] [Indexed: 10/18/2022]
Abstract
In living systems, iron is found in many different structures, including Fe/S clusters, hemes and nonheme centers, and magnetically interacting aggregates. Understanding Fe metabolism and trafficking will require biophysical spectroscopic tools that can evaluate the types of Fe centers within entire cells and isolated organelles. Mössbauer spectroscopy will play an important role in such analyses, as it has perhaps the best combination of resolution, sensitivity, coverage, and quantifying abilities. Other spectroscopic techniques, with particular strengths, will be used in combination with Mössbauer, and results will be integrated to assess the 'ironome' of such complex samples. This integrative biophysical approach is illustrated by a discussion of iron trafficking in yeast cells.
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Affiliation(s)
- Paul A Lindahl
- Department of Chemistry, Texas A&M University, College Station, TX 77843-3255, USA.
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Current awareness on yeast. Yeast 2010. [DOI: 10.1002/yea.1723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Tsai CL, Barondeau DP. Human frataxin is an allosteric switch that activates the Fe-S cluster biosynthetic complex. Biochemistry 2010; 49:9132-9. [PMID: 20873749 DOI: 10.1021/bi1013062] [Citation(s) in RCA: 225] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cellular depletion of the human protein frataxin is correlated with the neurodegenerative disease Friedreich's ataxia and results in the inactivation of Fe-S cluster proteins. Most researchers agree that frataxin functions in the biogenesis of Fe-S clusters, but its precise role in this process is unclear. Here we provide in vitro evidence that human frataxin binds to a Nfs1, Isd11, and Isu2 complex to generate the four-component core machinery for Fe-S cluster biosynthesis. Frataxin binding dramatically changes the K(M) for cysteine from 0.59 to 0.011 mM and the catalytic efficiency (k(cat)/K(M)) of the cysteine desulfurase from 25 to 7900 M⁻¹s⁻¹. Oxidizing conditions diminish the levels of both complex formation and frataxin-based activation, whereas ferrous iron further stimulates cysteine desulfurase activity. Together, these results indicate human frataxin functions with Fe(2+) as an allosteric activator that triggers sulfur delivery and Fe-S cluster assembly. We propose a model in which cellular frataxin levels regulate human Fe-S cluster biosynthesis that has implications for mitochondrial dysfunction, oxidative stress response, and both neurodegenerative and cardiovascular disease.
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Affiliation(s)
- Chi-Lin Tsai
- Department of Chemistry, Texas A&M University, College Station, TX 77842, USA
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Kell DB. Towards a unifying, systems biology understanding of large-scale cellular death and destruction caused by poorly liganded iron: Parkinson's, Huntington's, Alzheimer's, prions, bactericides, chemical toxicology and others as examples. Arch Toxicol 2010; 84:825-89. [PMID: 20967426 PMCID: PMC2988997 DOI: 10.1007/s00204-010-0577-x] [Citation(s) in RCA: 286] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Accepted: 07/14/2010] [Indexed: 12/11/2022]
Abstract
Exposure to a variety of toxins and/or infectious agents leads to disease, degeneration and death, often characterised by circumstances in which cells or tissues do not merely die and cease to function but may be more or less entirely obliterated. It is then legitimate to ask the question as to whether, despite the many kinds of agent involved, there may be at least some unifying mechanisms of such cell death and destruction. I summarise the evidence that in a great many cases, one underlying mechanism, providing major stresses of this type, entails continuing and autocatalytic production (based on positive feedback mechanisms) of hydroxyl radicals via Fenton chemistry involving poorly liganded iron, leading to cell death via apoptosis (probably including via pathways induced by changes in the NF-κB system). While every pathway is in some sense connected to every other one, I highlight the literature evidence suggesting that the degenerative effects of many diseases and toxicological insults converge on iron dysregulation. This highlights specifically the role of iron metabolism, and the detailed speciation of iron, in chemical and other toxicology, and has significant implications for the use of iron chelating substances (probably in partnership with appropriate anti-oxidants) as nutritional or therapeutic agents in inhibiting both the progression of these mainly degenerative diseases and the sequelae of both chronic and acute toxin exposure. The complexity of biochemical networks, especially those involving autocatalytic behaviour and positive feedbacks, means that multiple interventions (e.g. of iron chelators plus antioxidants) are likely to prove most effective. A variety of systems biology approaches, that I summarise, can predict both the mechanisms involved in these cell death pathways and the optimal sites of action for nutritional or pharmacological interventions.
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Affiliation(s)
- Douglas B Kell
- School of Chemistry and the Manchester Interdisciplinary Biocentre, The University of Manchester, Manchester M1 7DN, UK.
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