1
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Foley A, Lao N, Clarke C, Barron N. A complete workflow for single cell mtDNAseq in CHO cells, from cell culture to bioinformatic analysis. Front Bioeng Biotechnol 2024; 12:1304951. [PMID: 38440325 PMCID: PMC10910102 DOI: 10.3389/fbioe.2024.1304951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Accepted: 01/09/2024] [Indexed: 03/06/2024] Open
Abstract
Chinese hamster ovary (CHO) cells have a long history in the biopharmaceutical industry and currently produce the vast majority of recombinant therapeutic proteins. A key step in controlling the process and product consistency is the development of a producer cell line derived from a single cell clone. However, it is recognized that genetic and phenotypic heterogeneity between individual cells in a clonal CHO population tends to arise over time. Previous bulk analysis of CHO cell populations revealed considerable variation within the mtDNA sequence (heteroplasmy), which could have implications for the performance of the cell line. By analyzing the heteroplasmy of single cells within the same population, this heterogeneity can be characterized with greater resolution. Such analysis may identify heterogeneity in the mitochondrial genome, which impacts the overall phenotypic performance of a producer cell population, and potentially reveal routes for genetic engineering. A critical first step is the development of robust experimental and computational methods to enable single cell mtDNA sequencing (termed scmtDNAseq). Here, we present a protocol from cell culture to bioinformatic analysis and provide preliminary evidence of significant mtDNA heteroplasmy across a small panel of single CHO cells.
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Affiliation(s)
- Alan Foley
- Cell Engineering Group, National Institute for Bioprocessing Research and Training, Dublin, Ireland
- School of Chemical and Bioprocess Engineering, University College Dublin, Dublin, Ireland
| | - Nga Lao
- Cell Engineering Group, National Institute for Bioprocessing Research and Training, Dublin, Ireland
| | - Colin Clarke
- School of Chemical and Bioprocess Engineering, University College Dublin, Dublin, Ireland
- Bioinformatics Group, National Institute for Bioprocessing Research and Training, Dublin, Ireland
| | - Niall Barron
- Cell Engineering Group, National Institute for Bioprocessing Research and Training, Dublin, Ireland
- School of Chemical and Bioprocess Engineering, University College Dublin, Dublin, Ireland
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2
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Veloso Ribeiro Franco L, Barros MH. Biolistic transformation of the yeast Saccharomyces cerevisiae mitochondrial DNA. IUBMB Life 2023; 75:972-982. [PMID: 37470229 DOI: 10.1002/iub.2769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 06/23/2023] [Indexed: 07/21/2023]
Abstract
The insertion of genes into mitochondria by biolistic transformation is currently only possible in the yeast Saccharomyces cerevisiae and the algae Chlamydomonas reinhardtii. The fact that S. cerevisiae mitochondria can exist with partial (ρ- mutants) or complete deletions (ρ0 mutants) of mitochondrial DNA (mtDNA), without requiring a specific origin of replication, enables the propagation of exogenous sequences. Additionally, mtDNA in this organism undergoes efficient homologous recombination, making it well-suited for genetic manipulation. In this review, we present a summarized historical overview of the development of biolistic transformation and discuss iconic applications of the technique. We also provide a detailed example on how to obtain transformants with recombined foreign DNA in their mitochondrial genome.
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Affiliation(s)
| | - Mario H Barros
- Department of Microbiology, Institute of Biomedical Sciences, Universidade de Sao Paulo, Sao Paulo, Brazil
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3
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Hydrogen bonding rearrangement by a mitochondrial disease mutation in cytochrome bc 1 perturbs heme b H redox potential and spin state. Proc Natl Acad Sci U S A 2021; 118:2026169118. [PMID: 34389670 PMCID: PMC8379992 DOI: 10.1073/pnas.2026169118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
To perform their specific electron-transfer relay functions, hemes commonly adopt low spin states with fine-tuned redox potentials. Understanding molecular elements controlling these properties is crucial for the description of natural proteins and engineering redox-active systems. We describe unusual effects of mitochondrial disease-related mutation in cytochrome bc1, based on which we identify a dual role of hydrogen bonding to the propionate group of heme bH. We observe that stabilization of the hydrogen bond in mutant enhances the redox potential but destabilizes the low spin state of oxidized heme. This demonstrates a critical role of the hydrogen bonding, and heme-protein interactions in general, to secure a suitable redox potential and spin state, a notion that might be universal for other heme proteins. Hemes are common elements of biological redox cofactor chains involved in rapid electron transfer. While the redox properties of hemes and the stability of the spin state are recognized as key determinants of their function, understanding the molecular basis of control of these properties is challenging. Here, benefiting from the effects of one mitochondrial disease–related point mutation in cytochrome b, we identify a dual role of hydrogen bonding (H-bond) to the propionate group of heme bH of cytochrome bc1, a common component of energy-conserving systems. We found that replacing conserved glycine with serine in the vicinity of heme bH caused stabilization of this bond, which not only increased the redox potential of the heme but also induced structural and energetic changes in interactions between Fe ion and axial histidine ligands. The latter led to a reversible spin conversion of the oxidized Fe from 1/2 to 5/2, an effect that potentially reduces the electron transfer rate between the heme and its redox partners. We thus propose that H-bond to the propionate group and heme-protein packing contribute to the fine-tuning of the redox potential of heme and maintaining its proper spin state. A subtle balance is needed between these two contributions: While increasing the H-bond stability raises the heme potential, the extent of increase must be limited to maintain the low spin and diamagnetic form of heme. This principle might apply to other native heme proteins and can be exploited in engineering of artificial heme-containing protein maquettes.
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4
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Sarewicz M, Pintscher S, Pietras R, Borek A, Bujnowicz Ł, Hanke G, Cramer WA, Finazzi G, Osyczka A. Catalytic Reactions and Energy Conservation in the Cytochrome bc1 and b6f Complexes of Energy-Transducing Membranes. Chem Rev 2021; 121:2020-2108. [PMID: 33464892 PMCID: PMC7908018 DOI: 10.1021/acs.chemrev.0c00712] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Indexed: 12/16/2022]
Abstract
This review focuses on key components of respiratory and photosynthetic energy-transduction systems: the cytochrome bc1 and b6f (Cytbc1/b6f) membranous multisubunit homodimeric complexes. These remarkable molecular machines catalyze electron transfer from membranous quinones to water-soluble electron carriers (such as cytochromes c or plastocyanin), coupling electron flow to proton translocation across the energy-transducing membrane and contributing to the generation of a transmembrane electrochemical potential gradient, which powers cellular metabolism in the majority of living organisms. Cytsbc1/b6f share many similarities but also have significant differences. While decades of research have provided extensive knowledge on these enzymes, several important aspects of their molecular mechanisms remain to be elucidated. We summarize a broad range of structural, mechanistic, and physiological aspects required for function of Cytbc1/b6f, combining textbook fundamentals with new intriguing concepts that have emerged from more recent studies. The discussion covers but is not limited to (i) mechanisms of energy-conserving bifurcation of electron pathway and energy-wasting superoxide generation at the quinol oxidation site, (ii) the mechanism by which semiquinone is stabilized at the quinone reduction site, (iii) interactions with substrates and specific inhibitors, (iv) intermonomer electron transfer and the role of a dimeric complex, and (v) higher levels of organization and regulation that involve Cytsbc1/b6f. In addressing these topics, we point out existing uncertainties and controversies, which, as suggested, will drive further research in this field.
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Affiliation(s)
- Marcin Sarewicz
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Sebastian Pintscher
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Rafał Pietras
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Arkadiusz Borek
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Łukasz Bujnowicz
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Guy Hanke
- School
of Biological and Chemical Sciences, Queen
Mary University of London, London E1 4NS, U.K.
| | - William A. Cramer
- Department
of Biological Sciences, Purdue University, West Lafayette, Indiana 47907 United States
| | - Giovanni Finazzi
- Laboratoire
de Physiologie Cellulaire et Végétale, Université Grenoble Alpes, Centre National Recherche Scientifique,
Commissariat Energie Atomique et Energies Alternatives, Institut National
Recherche l’agriculture, l’alimentation et l’environnement, 38054 Grenoble Cedex 9, France
| | - Artur Osyczka
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
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5
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McPhillie MJ, Zhou Y, Hickman MR, Gordon JA, Weber CR, Li Q, Lee PJ, Amporndanai K, Johnson RM, Darby H, Woods S, Li ZH, Priestley RS, Ristroph KD, Biering SB, El Bissati K, Hwang S, Hakim FE, Dovgin SM, Lykins JD, Roberts L, Hargrave K, Cong H, Sinai AP, Muench SP, Dubey JP, Prud'homme RK, Lorenzi HA, Biagini GA, Moreno SN, Roberts CW, Antonyuk SV, Fishwick CWG, McLeod R. Potent Tetrahydroquinolone Eliminates Apicomplexan Parasites. Front Cell Infect Microbiol 2020; 10:203. [PMID: 32626661 PMCID: PMC7311950 DOI: 10.3389/fcimb.2020.00203] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 04/16/2020] [Indexed: 12/29/2022] Open
Abstract
Apicomplexan infections cause substantial morbidity and mortality, worldwide. New, improved therapies are needed. Herein, we create a next generation anti-apicomplexan lead compound, JAG21, a tetrahydroquinolone, with increased sp3-character to improve parasite selectivity. Relative to other cytochrome b inhibitors, JAG21 has improved solubility and ADMET properties, without need for pro-drug. JAG21 significantly reduces Toxoplasma gondii tachyzoites and encysted bradyzoites in vitro, and in primary and established chronic murine infections. Moreover, JAG21 treatment leads to 100% survival. Further, JAG21 is efficacious against drug-resistant Plasmodium falciparum in vitro. Causal prophylaxis and radical cure are achieved after P. berghei sporozoite infection with oral administration of a single dose (2.5 mg/kg) or 3 days treatment at reduced dose (0.625 mg/kg/day), eliminating parasitemia, and leading to 100% survival. Enzymatic, binding, and co-crystallography/pharmacophore studies demonstrate selectivity for apicomplexan relative to mammalian enzymes. JAG21 has significant promise as a pre-clinical candidate for prevention, treatment, and cure of toxoplasmosis and malaria.
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Affiliation(s)
| | - Ying Zhou
- Department of Ophthalmology and Visual Sciences, The University of Chicago, Chicago, IL, United States
| | - Mark R. Hickman
- Experimental Therapeutics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - James A. Gordon
- School of Chemistry, The University of Leeds, Leeds, United Kingdom
| | | | - Qigui Li
- Experimental Therapeutics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Patty J. Lee
- Experimental Therapeutics Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Kangsa Amporndanai
- Department of Biochemistry and Systems Biology, Faculty of Health and Life Sciences, Institute of Systems, Molecular and Integrative Biology, The University of Liverpool, Liverpool, United Kingdom
| | - Rachel M. Johnson
- School of Biomedical Sciences, Faculty of Biological Sciences, and Astbury Centre for Structural Molecular Biology, The University of Leeds, Leeds, United Kingdom
| | - Heather Darby
- School of Chemistry, The University of Leeds, Leeds, United Kingdom
| | - Stuart Woods
- Strathclyde Institute of Pharmacy and Biomedical Sciences, The University of Strathclyde, Glasgow, United Kingdom
| | - Zhu-hong Li
- Department of Cellular Biology, Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States
| | - Richard S. Priestley
- Department of Tropical Disease Biology, Research Center for Drugs and Diagnostics, The Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Kurt D. Ristroph
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, United States
| | - Scott B. Biering
- Department of Pathology, The University of Chicago, Chicago, IL, United States
| | - Kamal El Bissati
- Department of Ophthalmology and Visual Sciences, The University of Chicago, Chicago, IL, United States
| | - Seungmin Hwang
- Department of Pathology, The University of Chicago, Chicago, IL, United States
| | - Farida Esaa Hakim
- Department of Ophthalmology and Visual Sciences, The University of Chicago, Chicago, IL, United States
| | - Sarah M. Dovgin
- Department of Ophthalmology and Visual Sciences, The University of Chicago, Chicago, IL, United States
| | - Joseph D. Lykins
- Department of Ophthalmology and Visual Sciences, The University of Chicago, Chicago, IL, United States
| | - Lucy Roberts
- Strathclyde Institute of Pharmacy and Biomedical Sciences, The University of Strathclyde, Glasgow, United Kingdom
| | - Kerrie Hargrave
- Strathclyde Institute of Pharmacy and Biomedical Sciences, The University of Strathclyde, Glasgow, United Kingdom
| | - Hua Cong
- School of Chemistry, The University of Leeds, Leeds, United Kingdom
| | - Anthony P. Sinai
- Microbiology, Immunology and Molecular Genetics, The University of Kentucky College of Medicine, Lexington, KY, United States
| | - Stephen P. Muench
- School of Biomedical Sciences, Faculty of Biological Sciences, and Astbury Centre for Structural Molecular Biology, The University of Leeds, Leeds, United Kingdom
| | - Jitender P. Dubey
- Animal Parasitic Diseases Laboratory (APDL), USDA-ARS, Beltsville, MD, United States
| | - Robert K. Prud'homme
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, United States
| | - Hernan A. Lorenzi
- Department of Infectious Diseases, J Craig Venter Institute, Rockville, MD, United States
| | - Giancarlo A. Biagini
- Department of Tropical Disease Biology, Research Center for Drugs and Diagnostics, The Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Silvia N. Moreno
- Department of Cellular Biology, Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States
| | - Craig W. Roberts
- Strathclyde Institute of Pharmacy and Biomedical Sciences, The University of Strathclyde, Glasgow, United Kingdom
| | - Svetlana V. Antonyuk
- Department of Biochemistry and Systems Biology, Faculty of Health and Life Sciences, Institute of Systems, Molecular and Integrative Biology, The University of Liverpool, Liverpool, United Kingdom
| | | | - Rima McLeod
- Department of Ophthalmology and Visual Sciences, The University of Chicago, Chicago, IL, United States
- Department of Pediatrics (Infectious Diseases), Institute of Genomics, Genetics, and Systems Biology, Global Health Center, Toxoplasmosis Center, CHeSS, The College, University of Chicago, Chicago, IL, United States
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6
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A common coupling mechanism for A-type heme-copper oxidases from bacteria to mitochondria. Proc Natl Acad Sci U S A 2020; 117:9349-9355. [PMID: 32291342 PMCID: PMC7196763 DOI: 10.1073/pnas.2001572117] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We present a comprehensive investigation of mitochondrial DNA-encoded variants of cytochrome c oxidase (CcO) that harbor mutations within their core catalytic subunit I, designed to interrogate the presently disputed functions of the three putative proton channels. We assess overall respiratory competence, specific CcO catalytic activity, and, most importantly, proton/electron (H+/e−) stoichiometry from adenosine diphosphate to oxygen ratio measurements on preparations of intact mitochondria. We unequivocally show that yeast mitochondrial CcO uses the D-channel to translocate protons across its hydrophilic core, providing direct evidence in support of a common proton pumping mechanism across all members of the A-type heme-copper oxidase superfamily, independent of their bacterial or mitochondrial origin. Mitochondria metabolize almost all the oxygen that we consume, reducing it to water by cytochrome c oxidase (CcO). CcO maximizes energy capture into the protonmotive force by pumping protons across the mitochondrial inner membrane. Forty years after the H+/e− stoichiometry was established, a consensus has yet to be reached on the route taken by pumped protons to traverse CcO’s hydrophobic core and on whether bacterial and mitochondrial CcOs operate via the same coupling mechanism. To resolve this, we exploited the unique amenability to mitochondrial DNA mutagenesis of the yeast Saccharomyces cerevisiae to introduce single point mutations in the hydrophilic pathways of CcO to test function. From adenosine diphosphate to oxygen ratio measurements on preparations of intact mitochondria, we definitely established that the D-channel, and not the H-channel, is the proton pump of the yeast mitochondrial enzyme, supporting an identical coupling mechanism in all forms of the enzyme.
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7
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Song Z, Hu Y, Iorga BI, Vallières C, Fisher N, Meunier B. Mutational analysis of the Q i-site proton pathway in yeast cytochrome bc 1 complex. Biochem Biophys Res Commun 2020; 523:615-619. [PMID: 31941609 DOI: 10.1016/j.bbrc.2019.12.102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 12/19/2019] [Indexed: 11/18/2022]
Abstract
The respiratory cytochrome bc1 complex functions as a protonmotive ubiquinol:cytochrome c oxidoreductase. Lysine 228 (K228) located within the quinol reduction (Qi) site of the bc1 complex, has been reported as a key residue for proton transfer during the redox chemistry cycle to substrate quinone at Qi. In yeast, while single mutations had no effect, the combination of K228L and F225L resulted in a severe respiratory growth defect and inhibition of O2 consumption in intact cells. The inhibition was overcome by uncoupling the mitochondrial membrane or by suppressor mutations in the region of K228L-F225L. We propose that the K228L mutation introduces energetic (and kinetic) barriers into normal electron- and proton transfer chemistry at Qi, which are relieved by dissipation of the opposing protonmotive force or through the restoration of favourable intraprotein proton transfer networks via suppressor mutation.
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Affiliation(s)
- Zehua Song
- Translational Research Institute, Henan Provincial People's Hospital, School of Medicine, Henan University, Zhengzhou, China
| | - Yangfeng Hu
- Translational Research Institute, Henan Provincial People's Hospital, School of Medicine, Henan University, Zhengzhou, China
| | - Bogdan I Iorga
- Université Paris-Saclay, CNRS, Institut de Chimie des Substances Naturelles, UPR 2301, 91198, Gif-sur-Yvette, France
| | - Cindy Vallières
- School of Life Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Nicholas Fisher
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA.
| | - Brigitte Meunier
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France.
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8
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Mounkoro P, Michel T, Blandin S, Golinelli-Cohen MP, Davioud-Charvet E, Meunier B. Investigating the mode of action of the redox-active antimalarial drug plasmodione using the yeast model. Free Radic Biol Med 2019; 141:269-278. [PMID: 31238126 DOI: 10.1016/j.freeradbiomed.2019.06.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 06/21/2019] [Accepted: 06/21/2019] [Indexed: 10/26/2022]
Abstract
Malaria is caused by protozoan parasites and remains a major public health issue in subtropical areas. Plasmodione (3-[4-(trifluoromethyl)benzyl]-menadione) is a novel early lead compound displaying fast-acting antimalarial activity. Treatment with this redox active compound disrupts the redox balance of parasite-infected red blood cells. In vitro, the benzoyl analogue of plasmodione can act as a subversive substrate of the parasite flavoprotein NADPH-dependent glutathione reductase, initiating a redox cycling process producing ROS. Whether this is also true in vivo remains to be investigated. Here, we used the yeast model to investigate the mode of action of plasmodione and uncover enzymes and pathways involved in its activity. We showed that plasmodione is a potent inhibitor of yeast respiratory growth, that in drug-treated cells, the ROS-sensitive aconitase was impaired and that cells with a lower oxidative stress defence were highly sensitive to the drug, indicating that plasmodione may act via an oxidative stress. We found that the mitochondrial respiratory chain flavoprotein NADH-dehydrogenases play a key role in plasmodione activity. Plasmodione and metabolites act as substrates of these enzymes, the reaction resulting in ROS production. This in turn would damage ROS-sensitive enzymes leading to growth arrest. Our data further suggest that plasmodione is a pro-drug whose activity is mainly mediated by its benzhydrol and benzoyl metabolites. Our results in yeast are coherent with existing data obtained in vitro and in Plasmodium falciparum, and provide additional hypotheses that should be investigated in parasites.
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Affiliation(s)
- Pierre Mounkoro
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette Cedex, France
| | - Thomas Michel
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette Cedex, France
| | - Stéphanie Blandin
- Université de Strasbourg, CNRS, Inserm, UPR9022/U1257, Mosquito Immune Responses (MIR), F-67000, Strasbourg, France
| | - Marie-Pierre Golinelli-Cohen
- Institut de Chimie des Substances Naturelles (ICSN), CNRS, UPR 2301, Univ. Paris-Sud Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France
| | - Elisabeth Davioud-Charvet
- Université de Strasbourg, Université de Haute-Alsace, Centre National de la Recherche Scientifique (CNRS), LIMA-UMR 7042, Team Bioorganic and Medicinal Chemistry, ECPM 25 Rue Becquerel, 67087, Strasbourg, France
| | - Brigitte Meunier
- 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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9
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Mounkoro P, Michel T, Benhachemi R, Surpateanu G, Iorga BI, Fisher N, Meunier B. Mitochondrial complex III Q i -site inhibitor resistance mutations found in laboratory selected mutants and field isolates. PEST MANAGEMENT SCIENCE 2019; 75:2107-2114. [PMID: 30426681 DOI: 10.1002/ps.5264] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 11/08/2018] [Accepted: 11/08/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND Complex III inhibitors targeting the Qi -site have been known for decades; some are used or being developed as antimicrobial compounds. Target site resistance mutations have been reported in laboratory-selected mutants and in field isolates. Here, we present a brief overview of mutations found in laboratory-selected resistant mutants. We also provide a study of mutations observed in field isolates of Plasmopara viticola, in particular the ametoctradin resistance substitution, S34L that we analysed in the yeast model. RESULTS A survey of laboratory mutants showed that resistance could be caused by a large number of substitutions in the Qi -site. Four residues seemed key in term of resistance: N31, G37, L198 and K228. Using yeast, we analysed the effect of the ametoctradin resistance substitution S34L reported in field isolates of P. viticola. We showed that S34L caused a high level of resistance combined with a loss of complex III activity and growth competence. CONCLUSION Use of single site Qi -site inhibitors is expected to result in the selection of resistant mutants. However, if the substitution is associated with a fitness penalty, as may be the case with S34L, resistance development might not be an insuperable obstacle, although careful monitoring is required. © 2018 Society of Chemical Industry.
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Affiliation(s)
- Pierre Mounkoro
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Thomas Michel
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Rafik Benhachemi
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Georgiana Surpateanu
- Institut de Chimie des Substances Naturelles, CNRS, UPR 2301, Université Paris-Saclay, Labex LERMIT, Gif-sur-Yvette, France
| | - Bogdan I Iorga
- Institut de Chimie des Substances Naturelles, CNRS, UPR 2301, Université Paris-Saclay, Labex LERMIT, Gif-sur-Yvette, France
| | - Nicholas Fisher
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, USA
| | - Brigitte Meunier
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
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10
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Okada-Junior C, Monteiro GC, Aguiar ACC, Batista VS, de Souza JO, Souza GE, Bueno RV, Oliva G, Nascimento-Júnior NM, Guido RVC, Bolzani VS. Phthalimide Derivatives with Bioactivity against Plasmodium falciparum: Synthesis, Evaluation, and Computational Studies Involving bc 1 Cytochrome Inhibition. ACS OMEGA 2018; 3:9424-9430. [PMID: 31459076 PMCID: PMC6644792 DOI: 10.1021/acsomega.8b01062] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Accepted: 08/02/2018] [Indexed: 06/10/2023]
Abstract
We describe herein the design and synthesis of N-phenyl phthalimide derivatives with inhibitory activities against Plasmodium falciparum (sensitive and resistant strains) in the low micromolar range and noticeable selectivity indices against human cells. The best inhibitor, 4-amino-2-(4-methoxyphenyl)isoindoline-1,3-dione (10), showed a slow-acting mechanism similar to that of atovaquone. Enzymatic assay indicated that 10 inhibited P. falciparum cytochrome bc 1 complex. Molecular docking studies suggested the binding mode of the best hit to Qo site of the cytochrome bc 1 complex. Our findings suggest that 10 is a promising candidate for hit-to-lead development.
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Affiliation(s)
- Celso
Yassuo Okada-Junior
- Nuclei
of Bioassays, Biosynthesis and Ecophysiology of Natural Products
(NuBBE), Department of Organic Chemistry, Institute of Chemistry, and Laboratory of
Medicinal Chemistry, Organic Synthesis and Molecular Modeling (LaQMedSOMM),
Department of Organic Chemistry, Institute of Chemistry, São Paulo State University—UNESP, Rua Professor Francisco Degni, 55,
Jardim Quitandinha, 14800-060 Araraquara, São Paulo, Brazil
| | - Gustavo Claro Monteiro
- Nuclei
of Bioassays, Biosynthesis and Ecophysiology of Natural Products
(NuBBE), Department of Organic Chemistry, Institute of Chemistry, and Laboratory of
Medicinal Chemistry, Organic Synthesis and Molecular Modeling (LaQMedSOMM),
Department of Organic Chemistry, Institute of Chemistry, São Paulo State University—UNESP, Rua Professor Francisco Degni, 55,
Jardim Quitandinha, 14800-060 Araraquara, São Paulo, Brazil
| | - Anna Caroline Campos Aguiar
- Sao
Carlos Institute of Physics, University
of Sao Paulo, Av. Joao
Dagnone, 1100 Jardim Santa Angelina, Sao Carlos, São Paulo 13563-120, Brazil
| | - Victor Sousa Batista
- Nuclei
of Bioassays, Biosynthesis and Ecophysiology of Natural Products
(NuBBE), Department of Organic Chemistry, Institute of Chemistry, and Laboratory of
Medicinal Chemistry, Organic Synthesis and Molecular Modeling (LaQMedSOMM),
Department of Organic Chemistry, Institute of Chemistry, São Paulo State University—UNESP, Rua Professor Francisco Degni, 55,
Jardim Quitandinha, 14800-060 Araraquara, São Paulo, Brazil
| | - Juliana Oliveira de Souza
- Sao
Carlos Institute of Physics, University
of Sao Paulo, Av. Joao
Dagnone, 1100 Jardim Santa Angelina, Sao Carlos, São Paulo 13563-120, Brazil
| | - Guilherme Eduardo Souza
- Sao
Carlos Institute of Physics, University
of Sao Paulo, Av. Joao
Dagnone, 1100 Jardim Santa Angelina, Sao Carlos, São Paulo 13563-120, Brazil
| | - Renata Vieira Bueno
- Sao
Carlos Institute of Physics, University
of Sao Paulo, Av. Joao
Dagnone, 1100 Jardim Santa Angelina, Sao Carlos, São Paulo 13563-120, Brazil
| | - Glaucius Oliva
- Sao
Carlos Institute of Physics, University
of Sao Paulo, Av. Joao
Dagnone, 1100 Jardim Santa Angelina, Sao Carlos, São Paulo 13563-120, Brazil
| | - Nailton M. Nascimento-Júnior
- Nuclei
of Bioassays, Biosynthesis and Ecophysiology of Natural Products
(NuBBE), Department of Organic Chemistry, Institute of Chemistry, and Laboratory of
Medicinal Chemistry, Organic Synthesis and Molecular Modeling (LaQMedSOMM),
Department of Organic Chemistry, Institute of Chemistry, São Paulo State University—UNESP, Rua Professor Francisco Degni, 55,
Jardim Quitandinha, 14800-060 Araraquara, São Paulo, Brazil
| | - Rafael Victorio Carvalho Guido
- Sao
Carlos Institute of Physics, University
of Sao Paulo, Av. Joao
Dagnone, 1100 Jardim Santa Angelina, Sao Carlos, São Paulo 13563-120, Brazil
| | - Vanderlan Silva Bolzani
- Nuclei
of Bioassays, Biosynthesis and Ecophysiology of Natural Products
(NuBBE), Department of Organic Chemistry, Institute of Chemistry, and Laboratory of
Medicinal Chemistry, Organic Synthesis and Molecular Modeling (LaQMedSOMM),
Department of Organic Chemistry, Institute of Chemistry, São Paulo State University—UNESP, Rua Professor Francisco Degni, 55,
Jardim Quitandinha, 14800-060 Araraquara, São Paulo, Brazil
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11
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Borek A, Ekiert R, Osyczka A. Functional flexibility of electron flow between quinol oxidation Q o site of cytochrome bc 1 and cytochrome c revealed by combinatory effects of mutations in cytochrome b, iron-sulfur protein and cytochrome c 1. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:754-761. [PMID: 29705394 DOI: 10.1016/j.bbabio.2018.04.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 04/16/2018] [Accepted: 04/24/2018] [Indexed: 01/07/2023]
Abstract
Transfer of electron from quinol to cytochrome c is an integral part of catalytic cycle of cytochrome bc1. It is a multi-step reaction involving: i) electron transfer from quinol bound at the catalytic Qo site to the Rieske iron-sulfur ([2Fe-2S]) cluster, ii) large-scale movement of a domain containing [2Fe-2S] cluster (ISP-HD) towards cytochrome c1, iii) reduction of cytochrome c1 by reduced [2Fe-2S] cluster, iv) reduction of cytochrome c by cytochrome c1. In this work, to examine this multi-step reaction we introduced various types of barriers for electron transfer within the chain of [2Fe-2S] cluster, cytochrome c1 and cytochrome c. The barriers included: impediment in the motion of ISP-HD, uphill electron transfer from [2Fe-2S] cluster to heme c1 of cytochrome c1, and impediment in the catalytic quinol oxidation. The barriers were introduced separately or in various combinations and their effects on enzymatic activity of cytochrome bc1 were compared. This analysis revealed significant degree of functional flexibility allowing the cofactor chains to accommodate certain structural and/or redox potential changes without losing overall electron and proton transfers capabilities. In some cases inhibitory effects compensated one another to improve/restore the function. The results support an equilibrium model in which a random oscillation of ISP-HD between the Qo site and cytochrome c1 helps maintaining redox equilibrium between all cofactors of the chain. We propose a new concept in which independence of the dynamics of the Qo site substrate and the motion of ISP-HD is one of the elements supporting this equilibrium and also is a potential factor limiting the overall catalytic rate.
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Affiliation(s)
- Arkadiusz Borek
- Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Robert Ekiert
- Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Artur Osyczka
- Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland.
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12
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Song Z, Iorga BI, Mounkoro P, Fisher N, Meunier B. The antimalarial compound
ELQ
‐400 is an unusual inhibitor of the
bc
1
complex, targeting both
Q
o
and
Q
i
sites. FEBS Lett 2018; 592:1346-1356. [DOI: 10.1002/1873-3468.13035] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 03/07/2018] [Accepted: 03/08/2018] [Indexed: 11/08/2022]
Affiliation(s)
- Zehua Song
- Translational Research Institute Henan Provincial People's Hospital School of Medicine Henan University Zhengzhou China
- Institute for Integrative Biology of the Cell (I2BC) CEA CNRS Université Paris‐Sud Université Paris‐Saclay Gif‐sur‐Yvette France
| | - Bogdan I. Iorga
- Institut de Chimie des Substances Naturelles CNRS UPR 2301 Labex LERMIT Université Paris‐Saclay Gif‐sur‐Yvette France
| | - Pierre Mounkoro
- Institute for Integrative Biology of the Cell (I2BC) CEA CNRS Université Paris‐Sud Université Paris‐Saclay Gif‐sur‐Yvette France
| | - Nicholas Fisher
- MSU‐DOE Plant Research Laboratory Michigan State University East Lansing MI USA
| | - Brigitte Meunier
- Institute for Integrative Biology of the Cell (I2BC) CEA CNRS Université Paris‐Sud Université Paris‐Saclay Gif‐sur‐Yvette France
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13
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Song Z, Laleve A, Vallières C, McGeehan JE, Lloyd RE, Meunier B. Human Mitochondrial Cytochrome b Variants Studied in Yeast: Not All Are Silent Polymorphisms. Hum Mutat 2016; 37:933-41. [PMID: 27291790 PMCID: PMC5094555 DOI: 10.1002/humu.23024] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 05/24/2016] [Indexed: 11/12/2022]
Abstract
Variations in mitochondrial DNA (mtDNA) cytochrome b (mt‐cyb) are frequently found within the healthy population, but also occur within a spectrum of mitochondrial and common diseases. mt‐cyb encodes the core subunit (MT‐CYB) of complex III, a central component of the oxidative phosphorylation system that drives cellular energy production and homeostasis. Despite significant efforts, most mt‐cyb variations identified are not matched with corresponding biochemical data, so their functional and pathogenic consequences in humans remain elusive. While human mtDNA is recalcitrant to genetic manipulation, it is possible to introduce human‐associated point mutations into yeast mtDNA. Using this system, we reveal direct links between human mt‐cyb variations in key catalytic domains of MT‐CYB and significant changes to complex III activity or drug sensitivity. Strikingly, m.15257G>A (p.Asp171Asn) increased the sensitivity of yeast to the antimalarial drug atovaquone, and m.14798T>C (p.Phe18Leu) enhanced the sensitivity of yeast to the antidepressant drug clomipramine. We demonstrate that while a small number of mt‐cyb variations had no functional effect, others have the capacity to alter complex III properties, suggesting they could play a wider role in human health and disease than previously thought. This compendium of new mt‐cyb‐biochemical relationships in yeast provides a resource for future investigations in humans.
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Affiliation(s)
- Zehua Song
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, Cedex, 91198, France
| | - Anaïs Laleve
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, Cedex, 91198, France
| | - Cindy Vallières
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, Cedex, 91198, France
| | - John E McGeehan
- Molecular Biophysics Laboratories, Institute of Biomedical and Biomolecular Science, School of Biological Sciences, University of Portsmouth, Portsmouth, UK
| | - Rhiannon E Lloyd
- Brain Tumour Research Centre, Institute of Biomedical and Biomolecular Science, School of Pharmacy and Biomedicine, University of Portsmouth, Portsmouth, UK
| | - Brigitte Meunier
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, Cedex, 91198, France
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14
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Jafari G, Wasko BM, Kaeberlein M, Crofts AR. New functional and biophysical insights into the mitochondrial Rieske iron-sulfur protein from genetic suppressor analysis in C. elegans. WORM 2016; 5:e1174803. [PMID: 27383074 DOI: 10.1080/21624054.2016.1174803] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 03/23/2016] [Accepted: 03/30/2016] [Indexed: 10/22/2022]
Abstract
Several intragenic mutations suppress the C. elegans isp-1(qm150) allele of the mitochondrial Rieske iron-sulfur protein (ISP), a catalytic subunit of Complex III of the respiratory chain. These mutations were located in a helical region of the "tether" span of ISP-1, distant from the primary mutation in the extrinsic head, and suppressed all pleiotropic phenotypes associated with the qm150 allele. Analysis of these suppressors revealed control of electron transfer into Complex III through a "spring-loaded" mechanism involving a binding force for formation of enzyme-substrate complex, counter balanced by forces (a chemical "spring") favoring helix formation in the tether. The primary P→S mutation results in inhibition of electron flow into the Q-cycle by decreasing the binding force, and the tether mutations relieve this inhibition by weakening the "spring." In this commentary we discuss additional control features, and relate the primary inhibition to outcomes at the organismal level. In particular, the sensitivity to hyperoxia and the elevated reactive oxygen species (ROS) seen in isp-1(qm150), likely reflect over-reduction of the quinone pool, which is upstream of the inhibited site; at high O2, this would lead to increased ROS production through complex I. We speculate that alternative NADH:ubiquinone oxidoreductase activity in C. elegans from the worm apoptosis inducing factor (AIF) homolog (WAH-1) might also be involved, and that WAH-1 might have a "canary" function in detection of this adverse state (high O2/reduced pool), and a role in protection of the organism by transformation to AIF-like products, and apoptotic recycling of defective cells.
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Affiliation(s)
- Gholamali Jafari
- Massachusetts General Hospital, Harvard Medical School , Boston, MA, USA
| | - Brian M Wasko
- Department of Pathology, University of Washington , Seattle, WA, USA
| | - Matt Kaeberlein
- Department of Pathology, University of Washington , Seattle, WA, USA
| | - Antony R Crofts
- Department of Biochemistry, University of Illinois at Urbana-Champaign , Urbana, IL, USA
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15
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Ekiert R, Borek A, Kuleta P, Czernek J, Osyczka A. Mitochondrial disease-related mutations at the cytochrome b-iron-sulfur protein (ISP) interface: Molecular effects on the large-scale motion of ISP and superoxide generation studied in Rhodobacter capsulatus cytochrome bc1. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1102-1110. [PMID: 27032290 PMCID: PMC4906154 DOI: 10.1016/j.bbabio.2016.03.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 03/21/2016] [Accepted: 03/22/2016] [Indexed: 01/06/2023]
Abstract
One of the important elements of operation of cytochrome bc1 (mitochondrial respiratory complex III) is a large scale movement of the head domain of iron–sulfur protein (ISP-HD), which connects the quinol oxidation site (Qo) located within the cytochrome b, with the outermost heme c1 of cytochrome c1. Several mitochondrial disease-related mutations in cytochrome b are located at the cytochrome b-ISP-HD interface, thus their molecular effects can be associated with altered motion of ISP-HD. Using purple bacterial model, we recently showed that one of such mutations — G167P shifts the equilibrium position of ISP-HD towards positions remote from the Qo site as compared to the native enzyme [Borek et al., J. Biol. Chem. 290 (2015) 23781-23792]. This resulted in the enhanced propensity of the mutant to generate reactive oxygen species (ROS) which was explained on the basis of the model evoking “semireverse” electron transfer from heme bL to quinone. Here we examine another mutation from that group — G332D (G290D in human), finding that it also shifts the equilibrium position of ISP-HD in the same direction, however displays less of the enhancement in ROS production. We provide spectroscopic indication that G332D might affect the electrostatics of interaction between cytochrome b and ISP-HD. This effect, in light of the measured enzymatic activities and electron transfer rates, appears to be less severe than structural distortion caused by proline in G167P mutant. Comparative analysis of the effects of G332D and G167P confirms a general prediction that mutations located at the cytochrome b-ISP-HD interface influence the motion of ISP-HD and indicates that “pushing” ISP-HD away from the Qo site is the most likely outcome of this influence. It can also be predicted that an increase in ROS production associated with the “pushing” effect is quite sensitive to overall severity of this change with more active mutants being generally more protected against elevated ROS. This article is part of a Special Issue entitled ‘EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2–6, 2016’, edited by Prof. Paolo Bernardi. Several mitochondrial mutations are located at the cytochrome b-ISP interface. We compare molecular effects of two mutations from that group. In both mutants ISP is shifted away from the Qo catalytic site. This effect is generally associated with increased ROS production. More active mutants are more protected against elevated ROS.
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Affiliation(s)
- Robert Ekiert
- Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Arkadiusz Borek
- Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Patryk Kuleta
- Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Justyna Czernek
- Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Artur Osyczka
- Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
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16
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Electron Transfer Reactions at the Qo Site of the Cytochrome bc 1 Complex: The Good, the Bad, and the Ugly. ADVANCES IN PHOTOSYNTHESIS AND RESPIRATION 2016. [DOI: 10.1007/978-94-017-7481-9_21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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17
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Tether mutations that restore function and suppress pleiotropic phenotypes of the C. elegans isp-1(qm150) Rieske iron-sulfur protein. Proc Natl Acad Sci U S A 2015; 112:E6148-57. [PMID: 26504246 DOI: 10.1073/pnas.1509416112] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mitochondria play an important role in numerous diseases as well as normative aging. Severe reduction in mitochondrial function contributes to childhood disorders such as Leigh Syndrome, whereas mild disruption can extend the lifespan of model organisms. The Caenorhabditis elegans isp-1 gene encodes the Rieske iron-sulfur protein subunit of cytochrome c oxidoreductase (complex III of the electron transport chain). The partial loss of function allele, isp-1(qm150), leads to several pleiotropic phenotypes. To better understand the molecular mechanisms of ISP-1 function, we sought to identify genetic suppressors of the delayed development of isp-1(qm150) animals. Here we report a series of intragenic suppressors, all located within a highly conserved six amino acid tether region of ISP-1. These intragenic mutations suppress all of the evaluated isp-1(qm150) phenotypes, including developmental rate, pharyngeal pumping rate, brood size, body movement, activation of the mitochondrial unfolded protein response reporter, CO2 production, mitochondrial oxidative phosphorylation, and lifespan extension. Furthermore, analogous mutations show a similar effect when engineered into the budding yeast Rieske iron-sulfur protein Rip1, revealing remarkable conservation of the structure-function relationship of these residues across highly divergent species. The focus on a single subunit as causal both in generation and in suppression of diverse pleiotropic phenotypes points to a common underlying molecular mechanism, for which we propose a "spring-loaded" model. These observations provide insights into how gating and control processes influence the function of ISP-1 in mediating pleiotropic phenotypes including developmental rate, movement, sensitivity to stress, and longevity.
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18
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Song Z, Clain J, Iorga BI, Vallières C, Lalève A, Fisher N, Meunier B. Interplay between the hinge region of iron sulphur protein and the Qo site in the bc1 complex - Analysis of Plasmodium-like mutations in the yeast enzyme. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:1487-94. [PMID: 26301481 DOI: 10.1016/j.bbabio.2015.08.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 07/21/2015] [Accepted: 08/19/2015] [Indexed: 10/23/2022]
Abstract
The respiratory chain bc1 complex is central to mitochondrial bioenergetics and the target of antiprotozoals. We characterized a modified yeast bc1 complex that more closely resemble Plasmodium falciparum enzyme. The mutant version was generated by replacing ten cytochrome b Qo site residues by P. falciparum equivalents. The Plasmodium-like changes caused a major dysfunction of the catalytic mechanism of the bc1 complex resulting in superoxide overproduction and respiratory growth defect. The defect was corrected by substitution of the conserved residue Y279 by a phenylalanine, or by mutations in or in the vicinity of the hinge domain of the iron-sulphur protein. It thus appears that side-reactions can be prevented by the substitution Y279F or the modification of the iron-sulphur protein hinge region. Interestingly, P. falciparum - and all the apicomplexan - contains an unusual hinge region. We replaced the yeast hinge region by the Plasmodium version and combined it with the Plasmodium-like version of the Qo site. This combination restored the respiratory growth competence. It could be suggested that, in the apicomplexan, the hinge region and the cytochrome b Qo site have co-evolved to maintain catalytic efficiency of the bc1 complex Qo site.
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Affiliation(s)
- Zehua Song
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, 91198 Gif-sur-Yvette, France
| | - Jérôme Clain
- UMR 216, Faculté de Pharmacie de Paris, Université Paris Descartes, and Institut de Recherche pour le Développement, 75006 Paris, France
| | - Bogdan I Iorga
- Institut de Chimie des Substances Naturelles, CNRS, UPR 2301, Labex LERMIT, 91198 Gif-sur-Yvette, France
| | - Cindy Vallières
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, 91198 Gif-sur-Yvette, France
| | - Anaïs Lalève
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, 91198 Gif-sur-Yvette, France
| | - Nicholas Fisher
- Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA..
| | - Brigitte Meunier
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, 91198 Gif-sur-Yvette, France.
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19
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Borek A, Kuleta P, Ekiert R, Pietras R, Sarewicz M, Osyczka A. Mitochondrial Disease-related Mutation G167P in Cytochrome b of Rhodobacter capsulatus Cytochrome bc1 (S151P in Human) Affects the Equilibrium Distribution of [2Fe-2S] Cluster and Generation of Superoxide. J Biol Chem 2015; 290:23781-92. [PMID: 26245902 PMCID: PMC4583038 DOI: 10.1074/jbc.m115.661314] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Indexed: 12/04/2022] Open
Abstract
Cytochrome bc1 is one of the key enzymes of many bioenergetic systems. Its operation involves a large scale movement of a head domain of iron-sulfur protein (ISP-HD), which functionally connects the catalytic quinol oxidation Qo site in cytochrome b with cytochrome c1. The Qo site under certain conditions can generate reactive oxygen species in the reaction scheme depending on the actual position of ISP-HD in respect to the Qo site. Here, using a bacterial system, we show that mutation G167P in cytochrome b shifts the equilibrium distribution of ISP-HD toward positions remote from the Qo site. This renders cytochrome bc1 non-functional in vivo. This effect is remediated by addition of alanine insertions (1Ala and 2Ala) in the neck region of the ISP subunit. These insertions, which on their own shift the equilibrium distribution of ISP-HD in the opposite direction (i.e. toward the Qo site), also act in this manner in the presence of G167P. Changes in the equilibrium distribution of ISP-HD in G167P lead to an increased propensity of cytochrome bc1 to generate superoxide, which becomes evident when the concentration of quinone increases. This result corroborates the recently proposed model in which “semireverse” electron transfer back to the Qo site, occurring when ISP-HD is remote from the site, favors reactive oxygen species production. G167P suggests possible molecular effects of S151P (corresponding in sequence to G167P) identified as a mitochondrial disease-related mutation in human cytochrome b. These effects may be valid for other human mutations that change the equilibrium distribution of ISP-HD in a manner similar to G167P.
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Affiliation(s)
- Arkadiusz Borek
- From the Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Patryk Kuleta
- From the Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Robert Ekiert
- From the Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Rafał Pietras
- From the Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Marcin Sarewicz
- From the Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Artur Osyczka
- From the Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
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20
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Saccharomyces cerevisiae-based mutational analysis of the bc1 complex Qo site residue 279 to study the trade-off between atovaquone resistance and function. Antimicrob Agents Chemother 2015; 59:4053-8. [PMID: 25918152 DOI: 10.1128/aac.00710-15] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 04/19/2015] [Indexed: 11/20/2022] Open
Abstract
The bc1 complex is central to mitochondrial bioenergetics and the target of the antimalarial drug atovaquone that binds in the quinol oxidation (Qo) site of the complex. Structural analysis has shown that the Qo site residue Y279 (Y268 in Plasmodium falciparum) is key for atovaquone binding. Consequently, atovaquone resistance can be acquired by mutation of that residue. In addition to the probability of amino acid substitution, the level of atovaquone resistance and the loss of bc1 complex activity that are associated with the novel amino acid would restrict the nature of resistance-driven mutations occurring on atovaquone exposure in native parasite populations. Using the yeast model, we characterized the effect of all the amino acid replacements resulting from a single nucleotide substitution at codon 279: Y279C, Y279D, Y279F, Y279H, Y279N, and Y279S (Y279C, D, F, H, N, and S). Two residue changes that required a double nucleotide substitution, Y279A and W, were added to the series. We found that mutations Y279A, C, and S conferred high atovaquone resistance but decreased the catalytic activity. Y279F had wild-type enzymatic activity and sensitivity to atovaquone, while the other substitutions caused a dramatic respiratory defect. The results obtained with the yeast model were examined in regard to atomic structure and compared to the reported data on the evolution of acquired atovaquone resistance in P. falciparum.
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21
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Hildenbeutel M, Hegg EL, Stephan K, Gruschke S, Meunier B, Ott M. Assembly factors monitor sequential hemylation of cytochrome b to regulate mitochondrial translation. ACTA ACUST UNITED AC 2014; 205:511-24. [PMID: 24841564 PMCID: PMC4033779 DOI: 10.1083/jcb.201401009] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mitochondrial respiratory chain complexes convert chemical energy into a membrane potential by connecting electron transport with charge separation. Electron transport relies on redox cofactors that occupy strategic positions in the complexes. How these redox cofactors are assembled into the complexes is not known. Cytochrome b, a central catalytic subunit of complex III, contains two heme bs. Here, we unravel the sequence of events in the mitochondrial inner membrane by which cytochrome b is hemylated. Heme incorporation occurs in a strict sequential process that involves interactions of the newly synthesized cytochrome b with assembly factors and structural complex III subunits. These interactions are functionally connected to cofactor acquisition that triggers the progression of cytochrome b through successive assembly intermediates. Failure to hemylate cytochrome b sequesters the Cbp3-Cbp6 complex in early assembly intermediates, thereby causing a reduction in cytochrome b synthesis via a feedback loop that senses hemylation of cytochrome b.
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Affiliation(s)
- Markus Hildenbeutel
- Department of Biochemistry and Biophysics, Center for Biomembrane Research, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Eric L Hegg
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI 48824
| | - Katharina Stephan
- Department of Biochemistry and Biophysics, Center for Biomembrane Research, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Steffi Gruschke
- Department of Biochemistry and Biophysics, Center for Biomembrane Research, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Brigitte Meunier
- Centre de Génétique Moléculaire du Centre National de la Recherche Scientifique (CNRS), 91198 Gif-sur-Yvette, France
| | - Martin Ott
- Department of Biochemistry and Biophysics, Center for Biomembrane Research, Stockholm University, SE-106 91 Stockholm, Sweden
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22
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Loo JH, Trejaut JA, Yen JC, Chen ZS, Ng WM, Huang CY, Hsu KN, Hung KH, Hsiao Y, Wei YH, Lin M. Mitochondrial DNA association study of type 2 diabetes with or without ischemic stroke in Taiwan. BMC Res Notes 2014; 7:223. [PMID: 24713204 PMCID: PMC4108081 DOI: 10.1186/1756-0500-7-223] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 04/01/2014] [Indexed: 11/10/2022] Open
Abstract
Background The importance of mitochondrial DNA (mtDNA) polymorphism in the prediction of type 2 diabetes (T2D) in men and women is not well understood. We questioned whether mtDNA polymorphism, mitochondrial functions, age and gender influenced the occurrence of T2D with or without ischemic stroke (IS). Methods We first designed a matched case–control study of 373 T2D patients and 327 healthy unrelated individuals without history of IS. MtDNA haplogroups were determined on all participants using sequencing of the control region and relevant SNPs from the coding region. Mitochondria functional tests, systemic biochemical measurements and complete genomic mtDNA sequencing were further determined on 239 participants (73 healthy controls, 33 T2D with IS, 70 T2D only and 63 IS patients without T2D). Results MtDNA haplogroups B4a1a, and E2b1 showed significant association with T2D (P <0.05), and haplogroup D4 indicated resistance (P <0.05). Mitochondrial and systemic functional tests showed significantly less variance within groups bearing the same mtDNA haplotypes. There was a pronounced male excess among all T2D patients and prevalence of IS was seen only in the older population. Finally, nucleotide variant np 15746, a determinant of haplogroup G3 seen in Japanese and of B4a1a prevalent in Taiwanese was associated with T2D in both populations. Conclusions Men appeared more susceptible to T2D than women. Although the significant association of B4a1a and E2b1 with T2D ceased when corrected for multiple testings, these haplogroups are seen only among Taiwan Aborigines, Southeast Asian and the Pacific Ocean islanders where T2D is predominant. The data further suggested that physiological and biochemical measurements were influenced by the mtDNA genetic profile of the individual. More understanding of the function of the mitochondrion in the development of T2D might indicate ways of influencing the early course of the disease.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Marie Lin
- Mackay Memorial Hospital, No, 45, Mínshēng Rd, Danshui District, New Taipei City, Taiwan.
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23
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Pathological Mutations of the Mitochondrial Human Genome: the Instrumental Role of the Yeast S. cerevisiae. Diseases 2014. [DOI: 10.3390/diseases2010024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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24
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Antoine T, Fisher N, Amewu R, O'Neill PM, Ward SA, Biagini GA. Rapid kill of malaria parasites by artemisinin and semi-synthetic endoperoxides involves ROS-dependent depolarization of the membrane potential. J Antimicrob Chemother 2013; 69:1005-16. [PMID: 24335485 PMCID: PMC3956377 DOI: 10.1093/jac/dkt486] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Objectives Artemisinin and artemisinin semi-synthetic derivatives (collectively known as endoperoxides) are first-line antimalarials for the treatment of uncomplicated and severe malaria. Endoperoxides display very fast killing rates and are generally recalcitrant to parasite resistance development. These key pharmacodynamic features are a result of a complex mechanism of action, the details of which lack consensus. Here, we report on the primary physiological events leading to parasite death. Methods Parasite mitochondrial (ΔΨm) and plasma membrane (ΔΨp) electrochemical potentials were measured using real-time single-cell imaging following exposure to pharmacologically relevant concentrations of endoperoxides (artemisinin, dihydroartemisinin, artesunate and the synthetic tetraoxane RKA182). In addition, mitochondrial electron transport chain components NADH:quinone oxidoreductase (alternative complex I), bc1 (complex III) and cytochrome oxidase (complex IV) were investigated to determine their functional sensitivity to the various endoperoxides. Results Parasite exposure to endoperoxides resulted in rapid depolarization of parasite ΔΨm and ΔΨp. The rate of depolarization was decreased in the presence of a reactive oxygen species (ROS) scavenger and Fe3+ chelators. Depolarization of ΔΨm by endoperoxides is not believed to be through the inhibition of mitochondrial electron transport chain components, owing to the lack of significant inhibition when assayed directly. Conclusions The depolarization of ΔΨm and ΔΨp is shown to be mediated via the generation of ROS that are initiated by iron bioactivation of endoperoxides and/or catalysed by iron-dependent oxidative stress. These data are discussed in the context of current hypotheses concerning the mode of action of endoperoxides.
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Affiliation(s)
- Thomas Antoine
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Nicholas Fisher
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Richard Amewu
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, UK
| | - Paul M. O'Neill
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, UK
| | - Stephen A. Ward
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Giancarlo A. Biagini
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
- Corresponding author. Tel: +44-151-7053151; Fax: +44-151-7053371; E-mail:
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25
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Reconstructing the Qo site of Plasmodium falciparum bc 1 complex in the yeast enzyme. PLoS One 2013; 8:e71726. [PMID: 23951230 PMCID: PMC3741170 DOI: 10.1371/journal.pone.0071726] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 07/09/2013] [Indexed: 11/19/2022] Open
Abstract
The bc 1 complex of the mitochondrial respiratory chain is essential for Plasmodium falciparum proliferation, the causative agent of human malaria. Therefore, this enzyme is an attractive target for antimalarials. However, biochemical investigations of the parasite enzyme needed for the study of new drugs are challenging. In order to facilitate the study of new compounds targeting the enzyme, we are modifying the inhibitor binding sites of the yeast Saccharomyces cerevisiae to generate a complex that mimics the P. falciparum enzyme. In this study we focused on its Qo pocket, the site of atovaquone binding which is a leading antimalarial drug used in treatment and causal prophylaxis. We constructed and studied a series of mutants with modified Qo sites where yeast residues have been replaced by P. falciparum equivalents, or, for comparison, by human equivalents. Mitochondria were prepared from the yeast Plasmodium-like and human-like Qo mutants. We measured the bc 1 complex sensitivity to atovaquone, azoxystrobin, a Qo site targeting fungicide active against P. falciparum and RCQ06, a quinolone-derivative inhibitor of P. falciparum bc 1 complex.The data obtained highlighted variations in the Qo site that could explain the differences in inhibitor sensitivity between yeast, plasmodial and human enzymes. We showed that the yeast Plasmodium-like Qo mutants could be useful and easy-to-use tools for the study of that class of antimalarials.
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26
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Lanciano P, Khalfaoui-Hassani B, Selamoglu N, Ghelli A, Rugolo M, Daldal F. Molecular mechanisms of superoxide production by complex III: a bacterial versus human mitochondrial comparative case study. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1827:1332-9. [PMID: 23542447 DOI: 10.1016/j.bbabio.2013.03.009] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 02/14/2013] [Accepted: 03/20/2013] [Indexed: 12/23/2022]
Abstract
In this mini review, we briefly survey the molecular processes that lead to reactive oxygen species (ROS) production by the respiratory complex III (CIII or cytochrome bc1). In particular, we discuss the "forward" and "reverse" electron transfer pathways that lead to superoxide generation at the quinol oxidation (Qo) site of CIII, and the components that affect these reactions. We then describe and compare the properties of a bacterial (Rhodobacter capsulatus) mutant enzyme producing ROS with its mitochondrial (human cybrids) counterpart associated with a disease. The mutation under study is located at a highly conserved tyrosine residue of cytochrome b (Y302C in R. capsulatus and Y278C in human mitochondria) that is at the heart of the quinol oxidation (Qo) site of CIII. Similarities of the major findings of bacterial and human mitochondrial cases, including decreased catalytic activity of CIII, enhanced ROS production and ensuing cellular responses and damages, are remarkable. This case illustrates the usefulness of undertaking parallel and complementary studies using biologically different yet evolutionarily related systems, such as α-proteobacteria and human mitochondria. It progresses our understanding of CIII mechanism of function and ROS production, and underlines the possible importance of supra-molecular organization of bacterial and mitochondrial respiratory chains (i.e., respirasomes) and their potential disease-associated protective roles. This article is part of a Special Issue entitled: Respiratory complex III and related bc complexes.
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Affiliation(s)
- Pascal Lanciano
- University of Pennsylvania, Department of Biology, Philadelphia, PA, USA
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27
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Meunier B, Fisher N, Ransac S, Mazat JP, Brasseur G. Respiratory complex III dysfunction in humans and the use of yeast as a model organism to study mitochondrial myopathy and associated diseases. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1827:1346-61. [PMID: 23220121 DOI: 10.1016/j.bbabio.2012.11.015] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 11/21/2012] [Accepted: 11/28/2012] [Indexed: 11/25/2022]
Abstract
The bc1 complex or complex III is a central component of the aerobic respiratory chain in prokaryotic and eukaryotic organisms. It catalyzes the oxidation of quinols and the reduction of cytochrome c, establishing a proton motive force used to synthesize adenosine triphosphate (ATP) by the F1Fo ATP synthase. In eukaryotes, the complex III is located in the inner mitochondrial membrane. The genes coding for the complex III have a dual origin. While cytochrome b is encoded by the mitochondrial genome, all the other subunits are encoded by the nuclear genome. In this review, we compile an exhaustive list of the known human mutations and associated pathologies found in the mitochondrially-encoded cytochrome b gene as well as the fewer mutations in the nuclear genes coding for the complex III structural subunits and accessory proteins such as BCS1L involved in the assembly of the complex III. Due to the inherent difficulties of studying human biopsy material associated with complex III dysfunction, we also review the work that has been conducted to study the pathologies with the easy to handle eukaryotic microorganism, the yeast Saccharomyces cerevisiae. Phenotypes, biochemical data and possible effects due to the mutations are also discussed in the context of the known three-dimensional structure of the eukaryotic complex III. This article is part of a Special Issue entitled: Respiratory complex III and related bc complexes.
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Affiliation(s)
- B Meunier
- CNRS, Centre de Génétique Moléculaire, UPR 3404, Gif-sur-Yvette, F-91198, France
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28
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Victoria D, Burton R, Crofts AR. Role of the -PEWY-glutamate in catalysis at the Q(o)-site of the Cyt bc(1) complex. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1827:365-86. [PMID: 23123515 DOI: 10.1016/j.bbabio.2012.10.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 10/19/2012] [Accepted: 10/23/2012] [Indexed: 01/09/2023]
Abstract
We re-examine the pH dependence of partial processes of ubihydroquinone (QH(2)) turnover in Glu-295 mutants in Rhodobacter sphaeroides to clarify the mechanistic role. In more crippled mutants, the bell-shaped pH profile of wildtype was replaced by dependence on a single pK at ~8.5 favoring electron transfer. Loss of the pK at 6.5 reflects a change in the rate-limiting step from the first to the second electron transfer. Over the range of pH 6-8, no major pH dependence of formation of the initial reaction complex was seen, and the rates of bypass reactions were similar to the wildtype. Occupancy of the Q(o)-site by semiquinone (SQ) was similar in the wildtype and the Glu→Trp mutant. Since heme b(L) is initially oxidized in the latter, the bifurcated reaction can still occur, allowing estimation of an empirical rate constant <10(3)s(-1) for reduction of heme b(L) by SQ from the domain distal from heme b(L), a value 1000-fold smaller than that expected from distance. If the pK ~8.5 in mutant strains is due to deprotonation of the neutral semiquinone, with Q(•-) as electron donor to heme b(L), then in wildtype this low value would preclude mechanisms for normal flux in which semiquinone is constrained to this domain. A kinetic model in which Glu-295 catalyzes H(+) transfer from QH•, and delivery of the H(+) to exit channel(s) by rotational displacement, and facilitates rapid electron transfer from SQ to heme b(L) by allowing Q(•-) to move closer to the heme, accounts well for the observations.
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Affiliation(s)
- Doreen Victoria
- Department of Biochemistry, University of Illinois, Urbana, IL 61801, USA
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29
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HDQ, a potent inhibitor of Plasmodium falciparum proliferation, binds to the quinone reduction site of the cytochrome bc1 complex. Antimicrob Agents Chemother 2012; 56:3739-47. [PMID: 22547613 DOI: 10.1128/aac.00486-12] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The mitochondrial bc(1) complex is a multisubunit enzyme that catalyzes the transfer of electrons from ubiquinol to cytochrome c coupled to the vectorial translocation of protons across the inner mitochondrial membrane. The complex contains two distinct quinone-binding sites, the quinol oxidation site of the bc(1) complex (Q(o)) and the quinone reduction site (Q(i)), located on opposite sides of the membrane within cytochrome b. Inhibitors of the Q(o) site such as atovaquone, active against the bc(1) complex of Plasmodium falciparum, have been developed and formulated as antimalarial drugs. Unfortunately, single point mutations in the Q(o) site can rapidly render atovaquone ineffective. The development of drugs that could circumvent cross-resistance with atovaquone is needed. Here, we report on the mode of action of a potent inhibitor of P. falciparum proliferation, 1-hydroxy-2-dodecyl-4(1H)quinolone (HDQ). We show that the parasite bc(1) complex--from both control and atovaquone-resistant strains--is inhibited by submicromolar concentrations of HDQ, indicating that the two drugs have different targets within the complex. The binding site of HDQ was then determined by using a yeast model. Introduction of point mutations into the Q(i) site, namely, G33A, H204Y, M221Q, and K228M, markedly decreased HDQ inhibition. In contrast, known inhibitor resistance mutations at the Q(o) site did not cause HDQ resistance. This study, using HDQ as a proof-of-principle inhibitor, indicates that the Q(i) site of the bc(1) complex is a viable target for antimalarial drug development.
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30
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Fisher N, Abd Majid R, Antoine T, Al-Helal M, Warman AJ, Johnson DJ, Lawrenson AS, Ranson H, O'Neill PM, Ward SA, Biagini GA. Cytochrome b mutation Y268S conferring atovaquone resistance phenotype in malaria parasite results in reduced parasite bc1 catalytic turnover and protein expression. J Biol Chem 2012; 287:9731-9741. [PMID: 22282497 PMCID: PMC3322985 DOI: 10.1074/jbc.m111.324319] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Revised: 01/26/2012] [Indexed: 11/24/2022] Open
Abstract
Atovaquone is an anti-malarial drug used in combination with proguanil (e.g. Malarone(TM)) for the curative and prophylactic treatment of malaria. Atovaquone, a 2-hydroxynaphthoquinone, is a competitive inhibitor of the quinol oxidation (Q(o)) site of the mitochondrial cytochrome bc(1) complex. Inhibition of this enzyme results in the collapse of the mitochondrial membrane potential, disruption of pyrimidine biosynthesis, and subsequent parasite death. Resistance to atovaquone in the field is associated with point mutations in the Q(o) pocket of cytochrome b, most notably near the conserved Pro(260)-Glu(261)-Trp(262)-Tyr(263) (PEWY) region in the ef loop). The effect of this mutation has been extensively studied in model organisms but hitherto not in the parasite itself. Here, we have performed a molecular and biochemical characterization of an atovaquone-resistant field isolate, TM902CB. Molecular analysis of this strain reveals the presence of the Y268S mutation in cytochrome b. The Y268S mutation is shown to confer a 270-fold shift of the inhibitory constant (K(i)) for atovaquone with a concomitant reduction in the V(max) of the bc(1) complex of ∼40% and a 3-fold increase in the observed K(m) for decylubiquinol. Western blotting analyses reveal a reduced iron-sulfur protein content in Y268S bc(1) suggestive of a weakened interaction between this subunit and cytochrome b. Gene expression analysis of the TM902CB strain reveals higher levels of expression, compared with the 3D7 (atovaquone-sensitive) control strain in bc(1) and cytochrome c oxidase genes. It is hypothesized that the observed differential expression of these and other key genes offsets the fitness cost resulting from reduced bc(1) activity.
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Affiliation(s)
- Nicholas Fisher
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom and
| | - Roslaini Abd Majid
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom and
| | - Thomas Antoine
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom and
| | - Mohammed Al-Helal
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom and
| | - Ashley J Warman
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom and
| | - David J Johnson
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom and
| | | | - Hilary Ranson
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom and
| | - Paul M O'Neill
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom
| | - Stephen A Ward
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom and.
| | - Giancarlo A Biagini
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom and.
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31
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Lee DW, Selamoglu N, Lanciano P, Cooley JW, Forquer I, Kramer DM, Daldal F. Loss of a conserved tyrosine residue of cytochrome b induces reactive oxygen species production by cytochrome bc1. J Biol Chem 2011; 286:18139-48. [PMID: 21454570 DOI: 10.1074/jbc.m110.214460] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Production of reactive oxygen species (ROS) induces oxidative damages, decreases cellular energy conversion efficiencies, and induces metabolic diseases in humans. During respiration, cytochrome bc(1) efficiently oxidizes hydroquinone to quinone, but how it performs this reaction without any leak of electrons to O(2) to yield ROS is not understood. Using the bacterial enzyme, here we show that a conserved Tyr residue of the cytochrome b subunit of cytochrome bc(1) is critical for this process. Substitution of this residue with other amino acids decreases cytochrome bc(1) activity and enhances ROS production. Moreover, the Tyr to Cys mutation cross-links together the cytochrome b and iron-sulfur subunits and renders the bacterial enzyme sensitive to O(2) by oxidative disruption of its catalytic [2Fe-2S] cluster. Hence, this Tyr residue is essential in controlling unproductive encounters between O(2) and catalytic intermediates at the quinol oxidation site of cytochrome bc(1) to prevent ROS generation. Remarkably, the same Tyr to Cys mutation is encountered in humans with mitochondrial disorders and in Plasmodium species that are resistant to the anti-malarial drug atovaquone. These findings illustrate the harmful consequences of this mutation in human diseases.
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Affiliation(s)
- Dong-Woo Lee
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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32
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Gómez-Durán A, Pacheu-Grau D, López-Pérez MJ, Montoya J, Ruiz-Pesini E. Mitochondrial pharma-Q-genomics: targeting the OXPHOS cytochrome b. Drug Discov Today 2010; 16:176-80. [PMID: 21112412 DOI: 10.1016/j.drudis.2010.11.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Accepted: 11/19/2010] [Indexed: 01/18/2023]
Abstract
Genetic variation in human cytochrome b generates structurally different coenzyme Q binding pockets, affects the coupling efficiency of the oxidative phosphorylation system and susceptibility to different medical conditions. As modification of coupling efficiency has already been shown to have therapeutic interest, these structural differences might be used to develop new drugs and allow for personalized medicine, giving rise to a new field: mitochondrial pharmacogenomics.
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Affiliation(s)
- Aurora Gómez-Durán
- Departamento de Bioquímica, Biología Molecular y Celular, Centro de Investigaciones, Biomédicas En Red de Enfermedades Raras (CIBERER), Instituto Aragonés de Ciencias de la Salud (I+CS), Spain
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33
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Rinaldi T, Dallabona C, Ferrero I, Frontali L, Bolotin-Fukuhara M. Mitochondrial diseases and the role of the yeast models. FEMS Yeast Res 2010; 10:1006-22. [PMID: 20946356 DOI: 10.1111/j.1567-1364.2010.00685.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Nowadays, mitochondrial diseases are recognized and studied with much attention and they cannot be considered anymore as 'rare diseases'. Yeast has been an instrumental organism to understand the genetic and molecular aspects of the many roles of mitochondria within the cells. Thanks to the general conservation of mitochondrial genes and pathways between human and yeast, it can also be used to model some diseases. In this review, we focus on the most recent topics, exemplifying those for which yeast models have been especially valuable.
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Affiliation(s)
- Teresa Rinaldi
- Department of Cell and Developmental Biology, Pasteur Institute-Cenci Bolognetti Foundation, Sapienza University of Rome, Rome, Italy
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34
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Discovery of potent small-molecule inhibitors of multidrug-resistant Plasmodium falciparum using a novel miniaturized high-throughput luciferase-based assay. Antimicrob Agents Chemother 2010; 54:3597-604. [PMID: 20547797 DOI: 10.1128/aac.00431-10] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Malaria is a global health problem that causes significant mortality and morbidity, with more than 1 million deaths per year caused by Plasmodium falciparum. Most antimalarial drugs face decreased efficacy due to the emergence of resistant parasites, which necessitates the discovery of new drugs. To identify new antimalarials, we developed an automated 384-well plate screening assay using P. falciparum parasites that stably express cytoplasmic firefly luciferase. After initial optimization, we tested two different types of compound libraries: known bioactive collections (Library of Pharmacologically Active Compounds [LOPAC] and the library from the National Institute of Neurological Disorders and Stroke [NINDS]) and a library of uncharacterized compounds (ChemBridge). A total of 12,320 compounds were screened at 5.5 microM. Selecting only compounds that reduced parasite growth by 85% resulted in 33 hits from the combined bioactive collection and 130 hits from the ChemBridge library. Fifteen novel drug-like compounds from the bioactive collection were found to be active against P. falciparum. Twelve new chemical scaffolds were found from the ChemBridge hits, the most potent of which was a series based on the 1,4-naphthoquinone scaffold, which is structurally similar to the FDA-approved antimalarial atovaquone. However, in contrast to atovaquone, which acts to inhibit the bc(1) complex and block the electron transport chain in parasite mitochondria, we have determined that our new 1,4-napthoquinones act in a novel, non-bc(1)-dependent mechanism and remain potent against atovaquone- and chloroquine-resistant parasites. Ultimately, this study may provide new probes to understand the molecular details of the malaria life cycle and to identify new antimalarials.
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35
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Kongkathip N, Pradidphol N, Hasitapan K, Grigg R, Kao WC, Hunte C, Fisher N, Warman AJ, Biagini GA, Kongsaeree P, Chuawong P, Kongkathip B. Transforming rhinacanthin analogues from potent anticancer agents into potent antimalarial agents. J Med Chem 2010; 53:1211-21. [PMID: 20067272 DOI: 10.1021/jm901545z] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Twenty-six novel naphthoquinone aliphatic esters were synthesized by esterification of 1,4-naphthoquinone alcohols with various aliphatic acids. The 1,4-naphthoquinone alcohols were prepared from 1-hydroxy-2-naphthoic acid in nine steps with excellent yields. Twenty-four of the novel synthetic naphthoquinone esters showed significant antimalarial activity with IC(50) values in the range of 0.03-16.63 microM. The length of the aliphatic chain and the presence of C-2' substituents on the propyl chain affected the activity. Interestingly, compounds 31 and 37 showed very good antimalarial activity and were not toxic to normal Vero cells, and the PTI values of 31 (>1990.38) and 37 (1825.94) are excellent. Both 31 and 37 showed potent inhibition against P. falciparum 3D7 cyt bc(1) and no inhibition on rat cyt bc(1). They showed IC(50) values in the nanomolar range, providing full inhibition of cyt bc(1) with one molecule inhibitor bound per cyt bc(1) monomer at the Q(o) site.
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Affiliation(s)
- Ngampong Kongkathip
- Natural Products and Organic Synthesis Research Unit (NPOS), Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Kasetsart University, Jatujak, Bangkok 10900, Thailand.
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36
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Cape JL, Aidasani D, Kramer DM, Bowman MK. Substrate redox potential controls superoxide production kinetics in the cytochrome bc complex. Biochemistry 2009; 48:10716-23. [PMID: 19810688 DOI: 10.1021/bi901205w] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The Q-cycle mechanism of the cytochrome bc(1) complex maximizes energy conversion during the transport of electrons from ubiquinol to cytochrome c (or alternate physiological acceptors), yet important steps in the Q-cycle are still hotly debated, including bifurcated electron transport, the high yield and specificity of the Q-cycle despite possible short-circuits and bypass reactions, and the rarity of observable intermediates in the oxidation of quinol. Mounting evidence shows that some bypass reactions producing superoxide during oxidation of quinol at the Q(o) site diverge from the Q-cycle rather late in the bifurcated reaction and provide an additional means of studying initial reactions of the Q-cycle. Bypass reactions offer more scope for controlling and manipulating reaction conditions, e.g., redox potential, because they effectively isolate or decouple the Q-cycle initial reactions from later steps, preventing many complications and interactions. We examine the dependence of oxidation rate on substrate redox potential in the yeast cytochrome bc(1) complex and find that the rate limitation occurs at the level of direct one-electron oxidation of quinol to semiquinone by the Rieske protein. Oxidation of semiquinone and reduction of cyt b or O(2) are subsequent, distinct steps. These experimental results are incompatible with models in which the transfer of electrons to the Rieske protein is not a distinct step preceding transfer of electrons to cytochrome b, and with conformational gating models that produce superoxide by different rate-limiting reactions from the normal Q-cycle.
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Affiliation(s)
- Jonathan L Cape
- Institute of Biological Chemistry, Washington State University, 289 Clark Hall, Pullman, Washington 99164-6314, USA
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37
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Fontanesi F, Diaz F, Barrientos A. Evaluation of the mitochondrial respiratory chain and oxidative phosphorylation system using yeast models of OXPHOS deficiencies. ACTA ACUST UNITED AC 2009; Chapter 19:Unit19.5. [PMID: 19806592 DOI: 10.1002/0471142905.hg1905s63] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The oxidative phosphorylation (OXPHOS) system consists of five multimeric complexes embedded in the mitochondrial inner membrane. They work in concert to drive the aerobic synthesis of ATP. Mitochondrial and nuclear DNA mutations affecting the accumulation and function of these enzymes are the most common cause of mitochondrial diseases and have also been associated with neurodegeneration and aging. Several approaches for the assessment of the OXPHOS system enzymes have been developed. Based on the methods described elsewhere, this unit describes the creation and study of yeast models of mitochondrial OXPHOS deficiencies.
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Affiliation(s)
- Flavia Fontanesi
- University of Miami Miller School of Medicine, Miami, Florida, USA
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Carbonell P, Nussinov R, del Sol A. Energetic determinants of protein binding specificity: insights into protein interaction networks. Proteomics 2009; 9:1744-53. [PMID: 19253304 DOI: 10.1002/pmic.200800425] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
One of the challenges of the postgenomic era is to provide a more realistic representation of cellular processes by combining a systems biology description of functional networks with information on their interacting components. Here we carried out a systematic large-scale computational study on a structural protein-protein interaction network dataset in order to dissect thermodynamic characteristics of binding determining the interplay between protein affinity and specificity. As expected, interactions involving specific binding sites display higher affinities than those of promiscuous binding sites. Next, in order to investigate a possible role of modular distribution of hot spots in binding specificity, we divided binding sites into modules previously shown to be energetically independent. In general, hot spots that interact with different partners are located in different modules. We further observed that common hot spots tend to interact with partners exhibiting common binding motifs, whereas different hot spots tend to interact with partners with different motifs. Thus, energetic properties of binding sites provide insights into the way proteins modulate interactions with different partners. Knowledge of those factors playing a role in protein specificity is important for understanding how proteins acquire additional partners during evolution. It should also be useful in drug design.
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Affiliation(s)
- Pablo Carbonell
- Bioinformatics Research Unit, Research and Development Division, Fujirebio, Inc., Komiya-cho, Hachioji-shi, Tokyo, Japan
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Ding MG, di Rago JP, Trumpower BL. Combining Inhibitor Resistance-conferring Mutations in Cytochrome b Creates Conditional Synthetic Lethality in Saccharomyces cerevisiae. J Biol Chem 2009; 284:8478-85. [PMID: 19179332 DOI: 10.1074/jbc.m809278200] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mitochondrial cytochrome bc(1) complex is an essential respiratory enzyme in oxygen-utilizing eukaryotic cells. Its core subunit, cytochrome b, contains two sites, center P and center N, that participate in the electron transfer activity of the bc(1) complex and that can be blocked by specific inhibitors. In yeast, there are various point mutations that confer inhibitor resistance at center P or center N. However, there are no yeast strains in which the bc(1) complex is resistant to both center P and center N inhibitors. We attempted to create such strains by crossing yeast strains with inhibitor-resistant mutations at center P with yeast strains with inhibitor-resistant mutations at center N. Characterization of yeast colonies emerging from the cross revealed that there were multiple colonies resistant against either inhibitor alone but that the mutational changes were ineffective when combined and when the yeast were grown in the presence of both inhibitors. Inhibitor titrations of bc(1) complex activities in mitochondrial membranes from the various yeast mutants showed that a mutation that confers resistance to an inhibitor at center P, when combined with a mutation that confers resistance to an inhibitor at center N, eliminates or markedly decreases the resistance conferred by the center N mutation. These results indicate that there is a pathway for structural communication between the two active sites of cytochrome b and open new possibilities for the utilization of center N as a potential drug target.
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Affiliation(s)
- Martina G Ding
- Department of Biochemistry, Dartmouth Medical School, Hanover, New Hampshire 03755, USA
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Multiple defects in the respiratory chain lead to the repression of genes encoding components of the respiratory chain and TCA cycle enzymes. J Mol Biol 2009; 387:1081-91. [PMID: 19245817 DOI: 10.1016/j.jmb.2009.02.039] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2008] [Revised: 02/11/2009] [Accepted: 02/16/2009] [Indexed: 12/18/2022]
Abstract
Respiratory complexes III, IV and V are formed by components of both nuclear and mitochondrial origin and are embedded in the inner mitochondrial membrane. Their assembly requires the auxiliary factor Oxa1, and the absence of this protein has severe consequences on these three major respiratory chain enzymes. We have studied, in the yeast Saccharomyces cerevisiae, the effect of the loss of Oxa1 function and of other respiratory defects on the expression of nuclear genes encoding components of the respiratory complexes and tricarboxylic acid cycle enzymes. We observed that the concomitant decrease in the level of two respiratory enzymes, complexes III and IV, led to their repression. These genes are known targets of the transcriptional activator complex Hap2/3/4/5 that plays a central role in the reprogramming of yeast metabolism when cells switch from a fermenting, glucose-repressed state to a respiring, derepressed state. We found that the Hap4 protein, the regulatory subunit of the transcriptional complex, was present at a lower level in the oxa1 mutants whereas no change in HAP4 transcript level was observed, suggesting a posttranscriptional modulation. In addition, an altered mitochondrial morphology was observed in mutants with decreased expression of Hap2/3/4/5 target genes. We suggest that the aberrant mitochondrial morphology, presumably caused by the severely decreased level of at least two respiratory enzymes, might be part of the signalling pathway linking the mitochondrial defect and Hap2/3/4/5.
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Fisher N, Warman AJ, Ward SA, Biagini GA. Chapter 17 Type II NADH: Quinone Oxidoreductases of Plasmodium Falciparum and Mycobacterium Tuberculosis. Methods Enzymol 2009; 456:303-20. [DOI: 10.1016/s0076-6879(08)04417-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Kucharczyk R, Zick M, Bietenhader M, Rak M, Couplan E, Blondel M, Caubet SD, di Rago JP. Mitochondrial ATP synthase disorders: molecular mechanisms and the quest for curative therapeutic approaches. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2008; 1793:186-99. [PMID: 18620007 DOI: 10.1016/j.bbamcr.2008.06.012] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2008] [Revised: 06/06/2008] [Accepted: 06/11/2008] [Indexed: 01/09/2023]
Abstract
In mammals, the majority of cellular ATP is produced by the mitochondrial F1F(O)-ATP synthase through an elaborate catalytic mechanism. While most subunits of this enzymatic complex are encoded by the nuclear genome, a few essential components are encoded in the mitochondrial genome. The biogenesis of this multi-subunit enzyme is a sophisticated multi-step process that is regulated on levels of transcription, translation and assembly. Defects that result in diminished abundance or functional impairment of the F1F(O)-ATP synthase can cause a variety of severe neuromuscular disorders. Underlying mutations have been identified in both the nuclear and the mitochondrial DNA. The pathogenic mechanisms are only partially understood. Currently, the therapeutic options are extremely limited. Alternative methods of treatment have however been proposed, but still encounter several technical difficulties. The application of novel scientific approaches promises to deepen our understanding of the molecular mechanisms of the ATP synthase, unravel novel therapeutic pathways and improve the unfortunate situation of the patients suffering from such diseases.
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Affiliation(s)
- Roza Kucharczyk
- Institut de Biochimie et Génétique Cellulaires, CNRS-Université Bordeaux2, Bordeaux 33077, France
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Abstract
Chlamydomonas reinhardtii is a model organism to study photosynthesis, cellular division, flagellar biogenesis, and, more recently, mitochondrial function. It has distinct advantages in comparison to higher plants because it is unicellular, haploid, and amenable to tetrad analysis, and its three genomes are subject to specific transformation. It also has the possibility to grow either photoautotrophically or heterotrophically on acetate, making the assembly of the photosynthetic machinery not essential for cell viability. Methods developed allow the isolation of C. reinhardtii mitochondria free of thylakoid contaminants. We review the general procedures used for the biochemical characterization of mitochondria from this green alga.
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Biagini GA, Fisher N, Berry N, Stocks PA, Meunier B, Williams DP, Bonar-Law R, Bray PG, Owen A, O'Neill PM, Ward SA. Acridinediones: selective and potent inhibitors of the malaria parasite mitochondrial bc1 complex. Mol Pharmacol 2008; 73:1347-55. [PMID: 18319379 DOI: 10.1124/mol.108.045120] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The development of drug resistance to affordable drugs has contributed to a global increase in the number of deaths from malaria. This unacceptable situation has stimulated research for new drugs active against multidrug-resistant Plasmodium falciparum parasites. In this regard, we show here that deshydroxy-1-imino derivatives of acridine (i.e., dihydroacridinediones) are selective antimalarial drugs acting as potent (nanomolar K(i)) inhibitors of parasite mitochondrial bc(1) complex. Inhibition of the bc(1) complex led to a collapse of the mitochondrial membrane potential, resulting in cell death (IC(50) approximately 15 nM). The selectivity of one of the dihydroacridinediones against the parasite enzyme was some 5000-fold higher than for the human bc(1) complex, significantly higher ( approximately 200 fold) than that observed with atovaquone, a licensed bc(1)-specific antimalarial drug. Experiments performed with yeast manifesting mutations in the bc(1) complex reveal that binding is directed to the quinol oxidation site (Q(o)) of the bc(1) complex. This is supported by favorable binding energies for in silico docking of dihydroacridinediones to P. falciparum bc(1) Q(o). Dihydroacridinediones represent an entirely new class of bc(1) inhibitors and the potential of these compounds as novel antimalarial drugs is discussed.
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Affiliation(s)
- Giancarlo A Biagini
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
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Seddiki N, Meunier B, Lemesle-Meunier D, Brasseur G. Is Cytochrome b Glutamic Acid 272 a Quinol Binding Residue in the bc1 Complex of Saccharomyces cerevisiae? Biochemistry 2008; 47:2357-68. [DOI: 10.1021/bi701905a] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nadir Seddiki
- Laboratoire de Bioénergétique et Ingénierie des Protéines, CNRS, 31 Chemin Joseph Aiguier, 13402 Marseille cedex 20, France, and Centre de Génétique Moléculaire, CNRS, UPR 2167, Gif-sur-Yvette, F-91198, France
| | - Brigitte Meunier
- Laboratoire de Bioénergétique et Ingénierie des Protéines, CNRS, 31 Chemin Joseph Aiguier, 13402 Marseille cedex 20, France, and Centre de Génétique Moléculaire, CNRS, UPR 2167, Gif-sur-Yvette, F-91198, France
| | - Danielle Lemesle-Meunier
- Laboratoire de Bioénergétique et Ingénierie des Protéines, CNRS, 31 Chemin Joseph Aiguier, 13402 Marseille cedex 20, France, and Centre de Génétique Moléculaire, CNRS, UPR 2167, Gif-sur-Yvette, F-91198, France
| | - Gaël Brasseur
- Laboratoire de Bioénergétique et Ingénierie des Protéines, CNRS, 31 Chemin Joseph Aiguier, 13402 Marseille cedex 20, France, and Centre de Génétique Moléculaire, CNRS, UPR 2167, Gif-sur-Yvette, F-91198, France
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Quinol type compound in cytochrome c preparations leads to non-enzymatic reduction of cytochrome c during the measurement of complex III activity. Mitochondrion 2007; 8:155-63. [PMID: 18272433 DOI: 10.1016/j.mito.2007.12.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2007] [Revised: 11/30/2007] [Accepted: 12/11/2007] [Indexed: 10/22/2022]
Abstract
Measurement of complex III activity is critical to the diagnosis of human mitochondrial disease and the study of mitochondrial pathobiology. Activity is measured as the maximal rate of antimycin A-sensitive reduction of exogenous cytochrome c by detergent-solubilized mitochondria. Complex III activity exhibited an unexpected variation based upon the commercial source of cytochrome c owing to an increase in the antimycin A-insensitive background reduction of cytochrome c and variable increases in total activity. Analysis of cytochrome c (producing a high-background) by fast protein liquid chromatography yielded a contaminant peak containing a lipid extractable component with redox spectra and mass spectroscopy fragmentation suggestive of a quinol. Measurement of inhibitor-sensitive rates are critical for the accurate and reproducible measurement of complex III activity and serve as a key quality control to screen for non-enzymatic reactions that obscure complex III activity.
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Abstract
Inhibitors of the mitochondrial respiratory chain enzyme cytochrome bc1 (respiratory complex III) have been developed as antimicrobial agents. They are used in agriculture to control plant pathogenic fungi and in medicine against human pathogens, such as the malaria parasite Plasmodium falciparum, or Pneumocystis jiroveci (an opportunistic pathogenic fungus life-threatening in immuno-compromised patients). These respiratory inhibitors are thus effective against a broad range of important pathogens. Unfortunately, the problem of acquired resistance has rapidly emerged. A growing number of pathogen isolates resistant to inhibitor treatment have been reported, and this resistance is often linked to mutation within cytochrome b, one of the essential catalytic subunits of the complex. Saccharomyces cerevisiae is an invaluable model in order to assess the impact of the mutations on the sensitivity to the drugs, on the respiratory capacity and the fitness of cells. In this minireview, the inhibitors, their mode of action, and the mutations implicated in resistance and studied in yeast are briefly reviewed. Four mutations that are of particular importance in medicine and in agriculture are briefly reviewed and described in more detail and the molecular basis of resistance and of evolution of the mutations is discussed succinctly.
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Affiliation(s)
- Nick Fisher
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
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Hsu WT, Pang CNI, Sheetal J, Wilkins MR. Protein-protein interactions and disease: use of S. cerevisiae as a model system. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2007; 1774:838-47. [PMID: 17560182 DOI: 10.1016/j.bbapap.2007.04.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2006] [Revised: 04/27/2007] [Accepted: 04/27/2007] [Indexed: 10/23/2022]
Abstract
Disease-causing mutations are increasingly being studied to see if they cause the loss or gain of protein-protein interactions. Because the interaction network of humans is poorly understood and difficult to investigate, here we propose the use of Saccharomyces cerevisiae as a model system for understanding the impact of disease-causing mutations on protein-protein interactions. Alignments of human disease-associated proteins and 379 yeast orthologs showed that 124 of these proteins have >40% sequence identity, with some orthologs having up to 89% identity. A total of 1826 amino acid mutations associated with human disease were found to map to invariant amino acids in yeast. These mutations were proportionately more likely to be non-conservative than non-disease associated polymorphisms for the same proteins (p=0.016). Importantly, 73 of the mutations mapped to protein-protein interaction domains, implying a direct link between mutation and changes in protein interactivity. In the manuscript, all alignment information and tables that map mutations and diseases to yeast orthologs are given. This will help researchers experimentally test the impact of mutations on protein-protein interactions in S. cerevisiae and, by homology, explore the role of such mutations in the genesis of human disease.
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Affiliation(s)
- Wei-Tse Hsu
- School of Biotechnology and Biomolecular Science, University of New South Wales, NSW 2052, Australia
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Wenz T, Covian R, Hellwig P, Macmillan F, Meunier B, Trumpower BL, Hunte C. Mutational analysis of cytochrome b at the ubiquinol oxidation site of yeast complex III. J Biol Chem 2006; 282:3977-88. [PMID: 17145759 DOI: 10.1074/jbc.m606482200] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The cytochrome bc1 complex is a dimeric enzyme of the inner mitochondrial membrane that links electron transfer from ubiquinol to cytochrome c by a protonmotive Q cycle mechanism in which ubiquinol is oxidized at one center in the enzyme, referred to as center P, and ubiquinone is rereduced at a second center, referred to as center N. To better understand the mechanism of ubiquinol oxidation, we have examined catalytic activities and pre-steady-state reduction kinetics of yeast cytochrome bc1 complexes with mutations in cytochrome b that we expected would affect oxidation of ubiquinol. We mutated two residues thought to be involved in proton conduction linked to ubiquinol oxidation, Tyr132 and Glu272, and two residues proposed to be involved in docking ubiquinol into the center P pocket, Phe129 and Tyr279. Substitution of Phe129 by lysine or arginine yielded a respiration-deficient phenotype and lipid-dependent catalytic activity. Increased bypass reactions were detectable for both variants, with F129K showing the more severe effects. Substitution with lysine leads to a disturbed coordination of a b heme as deduced from changes in the midpoint potential and the EPR signature. Removal of the aromatic side chain in position Tyr279 lowers the catalytic activity accompanied by a low level of bypass reactions. Pre-steady-state kinetics of the enzymes modified at Glu272 and Tyr132 confirmed the importance of their functional groups for electron transfer. Altered center N kinetics and activation of ubiquinol oxidation by binding of cytochrome c in the Y132F and E272D enzymes indicate long range effects of these mutations.
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Affiliation(s)
- Tina Wenz
- Department Molecular Membrane Biology, Max Planck Institute of Biophysics, D-60438 Frankfurt am Main, Germany
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Solans A, Zambrano A, Rodríguez M, Barrientos A. Cytotoxicity of a mutant huntingtin fragment in yeast involves early alterations in mitochondrial OXPHOS complexes II and III. Hum Mol Genet 2006; 15:3063-81. [PMID: 16968735 DOI: 10.1093/hmg/ddl248] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Mitochondrial dysfunction may play an important role in the pathogenic mechanism of Huntington's disease (HD). However, the exact mechanism by which mutated huntingtin could cause bioenergetic dysfunction is still unknown. We have constructed a stable inducible yeast model of HD by expressing a human huntingtin fragment containing a mutant polyglutamine tract of 103Q fused to green fluorescent protein (GFP), and a control expressing a wild-type 25Q domain fused to GFP in a wild-type strain. We showed that in yeast cells expressing 103Q, cell respiration was progressively reduced after 4-6 h of induction with galactose, down to 50% of the control after 10 h of induction. The cell respiration defect results from an alteration in the function and amount of mitochondrial respiratory chain complex II+III, in congruency to data obtained from postmortem brain of HD patients and from toxin models. In our model, the production of reactive oxygen species (ROS) is significantly enhanced in cells expressing 103Q. Quenching of ROS with resveratrol partially prevents the cell respiration defect. Mitochondrial morphology and distribution were also altered in cells expressing 103Q, probably resulting from the interaction of aggregates with portions of the mitochondrial web and from a progressive disruption of the actin cytoskeleton. We propose a mechanism for mitochondrial dysfunction in our yeast model of HD in which the interactions of misfolded/aggregated polyglutamine domains with the mitochondrial and actin networks lead to disturbances in mitochondrial distribution and function and to increase in ROS production. Oxidative damage could preferentially affect the stability and function of enzymes containing iron-sulfur clusters such as complexes II and III. Our yeast model represents a very useful paradigm to study mitochondrial physiology alterations in the pathogenic mechanism of HD.
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Affiliation(s)
- Asun Solans
- Department of Neurology, Dr. John T. Macdonald Foundation Center for Medical Genetics, University of Miami, Miller School of Medicine, 1600 NW 10th Avenue, Miami, FL 33136, USA
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