1
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Jacobs HT, Szibor M, Rathkolb B, da Silva-Buttkus P, Aguilar-Pimentel JA, Amarie OV, Becker L, Calzada-Wack J, Dragano N, Garrett L, Gerlini R, Hölter SM, Klein-Rodewald T, Kraiger M, Leuchtenberger S, Marschall S, Östereicher MA, Pfannes K, Sanz-Moreno A, Seisenberger C, Spielmann N, Stoeger C, Wurst W, Fuchs H, Hrabě de Angelis M, Gailus-Durner V. AOX delays the onset of the lethal phenotype in a mouse model of Uqcrh ( complex III) disease. Biochim Biophys Acta Mol Basis Dis 2023; 1869:166760. [PMID: 37230398 DOI: 10.1016/j.bbadis.2023.166760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 04/24/2023] [Accepted: 05/16/2023] [Indexed: 05/27/2023]
Abstract
The alternative oxidase, AOX, provides a by-pass of the cytochrome segment of the mitochondrial respiratory chain when the chain is unavailable. AOX is absent from mammals, but AOX from Ciona intestinalis is benign when expressed in mice. Although non-protonmotive, so does not contribute directly to ATP production, it has been shown to modify and in some cases rescue phenotypes of respiratory-chain disease models. Here we studied the effect of C. intestinalis AOX on mice engineered to express a disease-equivalent mutant of Uqcrh, encoding the hinge subunit of mitochondrial respiratory complex III, which results in a complex metabolic phenotype beginning at 4-5 weeks, rapidly progressing to lethality within a further 6-7 weeks. AOX expression delayed the onset of this phenotype by several weeks, but provided no long-term benefit. We discuss the significance of this finding in light of the known and hypothesized effects of AOX on metabolism, redox homeostasis, oxidative stress and cell signaling. Although not a panacea, the ability of AOX to mitigate disease onset and progression means it could be useful in treatment.
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Affiliation(s)
- Howard T Jacobs
- Faculty of Medicine and Health Technology, FI-33014 Tampere University, Finland; Department of Environment and Genetics, La Trobe University, Melbourne, Victoria 3086, Australia.
| | - Marten Szibor
- Faculty of Medicine and Health Technology, FI-33014 Tampere University, Finland; Department of Cardiothoracic Surgery, Center for Sepsis Control and Care (CSCC), Jena University Hospital, Friedrich Schiller University of Jena, Am Klinikum 1, 07747 Jena, Germany
| | - Birgit Rathkolb
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany; Institute of Molecular Animal Breeding and Biotechnology, Gene Center, Ludwig-Maximilians-University München, Feodor-Lynen Str. 25, 81377 Munich, Germany; German Center for Diabetes Research (DZD), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany
| | - Patricia da Silva-Buttkus
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany
| | - Juan Antonio Aguilar-Pimentel
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany
| | - Oana V Amarie
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany
| | - Lore Becker
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany
| | - Julia Calzada-Wack
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany
| | - Nathalia Dragano
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany
| | - Lillian Garrett
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany
| | - Raffaele Gerlini
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany
| | - Sabine M Hölter
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany; Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany
| | - Tanja Klein-Rodewald
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany
| | - Markus Kraiger
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany
| | - Stefanie Leuchtenberger
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany
| | - Susan Marschall
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany
| | - Manuela A Östereicher
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany
| | - Kristina Pfannes
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany
| | - Adrián Sanz-Moreno
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany
| | - Claudia Seisenberger
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany
| | - Nadine Spielmann
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany
| | - Claudia Stoeger
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany
| | - Wolfgang Wurst
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany; Chair of Developmental Genetics, TUM School of Life Sciences, Technische Universität München, Freising-Weihenstephan, Germany; Deutsches Institut für Neurodegenerative Erkrankungen (DZNE) Site Munich, Feodor-Lynen-Str. 17, 81377 Munich, Germany
| | - Helmut Fuchs
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany
| | - Martin Hrabě de Angelis
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany; Chair of Experimental Genetics, TUM School of Life Sciences, Technische Universität München, Alte Akademie 8, 85354 Freising, Germany.
| | - Valérie Gailus-Durner
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstraße 1, 85764 Neuherberg, Germany
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2
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Sorrentino I, Galli M, Medraño-Fernandez I, Sitia R. Transfer of H 2O 2 from Mitochondria to the endoplasmic reticulum via Aquaporin-11. Redox Biol 2022; 55:102410. [PMID: 35863264 PMCID: PMC9304643 DOI: 10.1016/j.redox.2022.102410] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/12/2022] [Accepted: 07/12/2022] [Indexed: 01/20/2023] Open
Abstract
Some aquaporins (AQPs) can transport H2O2 across membranes, allowing redox signals to proceed in and between cells. Unlike other peroxiporins, human AQP11 is an endoplasmic reticulum (ER)-resident that can conduit H2O2 to the cytosol. Here, we show that silencing Ero1α, an ER flavoenzyme that generates abundant H2O2 during oxidative folding, causes a paradoxical increase in luminal H2O2 levels. The simultaneous AQP11 downregulation prevents this increase, implying that H2O2 reaches the ER from an external source(s). Pharmacological inhibition of the electron transport chain reveals that Ero1α downregulation activates superoxide production by complex III. In the intermembrane space, superoxide dismutase 1 generates H2O2 that enters the ER channeled by AQP11. Meanwhile, the number of ER-mitochondria contact sites increases as well, irrespective of AQP11 expression. Taken together, our findings identify a novel interorganellar redox response that is activated upon Ero1α downregulation and transfers H2O2 from mitochondria to the ER via AQP11.
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Affiliation(s)
- Ilaria Sorrentino
- Division of Genetics and Cell Biology, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Ospedale San Raffaele, Università Vita-Salute San Raffaele, 20132, Milan, Italy
| | - Mauro Galli
- Department of Medical Biology, Medical University of Białystok, 15222, Białystok, Poland
| | - Iria Medraño-Fernandez
- Department of Bioengineering and Aerospace Engineering, University Carlos III of Madrid, 28911, Madrid, Spain.
| | - Roberto Sitia
- Division of Genetics and Cell Biology, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Ospedale San Raffaele, Università Vita-Salute San Raffaele, 20132, Milan, Italy.
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3
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Chen CL, Kang PT, Zhang L, Xiao K, Zweier JL, Chilian WM, Chen YR. Reperfusion mediates heme impairment with increased protein cysteine sulfonation of mitochondrial complex III in the post-ischemic heart. J Mol Cell Cardiol 2021; 161:23-38. [PMID: 34331972 PMCID: PMC8629835 DOI: 10.1016/j.yjmcc.2021.07.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 07/08/2021] [Accepted: 07/21/2021] [Indexed: 11/19/2022]
Abstract
A serious consequence of myocardial ischemia-reperfusion injury (I/R) is oxidative damage, which causes mitochondrial dysfunction. The cascading ROS can propagate and potentially induce heme bleaching and protein cysteine sulfonation (PrSO3H) of the mitochondrial electron transport chain. Herein we studied the mechanism of I/R-mediated irreversible oxidative injury of complex III in mitochondria from rat hearts subjected to 30-min of ischemia and 24-h of reperfusion in vivo. In the I/R region, the catalytic activity of complex III was significantly impaired. Spectroscopic analysis indicated that I/R mediated the destruction of hemes b and c + c1 in the mitochondria, supporting I/R-mediated complex III impairment. However, no significant impairment of complex III activity and heme damage were observed in mitochondria from the risk region of rat hearts subjected only to 30-min ischemia, despite a decreased state 3 respiration. In the I/R mitochondria, carbamidomethylated C122/C125 of cytochrome c1 via alkylating complex III with a down regulation of HCCS was exclusively detected, supporting I/R-mediated thioether defect of heme c1. LC-MS/MS analysis showed that I/R mitochondria had intensely increased complex III PrSO3H levels at the C236 ligand of the [2Fe2S] cluster of the Rieske iron‑sulfur protein (uqcrfs1), thus impairing the electron transport activity. MS analysis also indicated increased PrSO3H of the hinge protein at C65 and of cytochrome c1 at C140 and C220, which are confined in the intermembrane space. MS analysis also showed that I/R extensively enhanced the PrSO3H of the core 1 (uqcrc1) and core 2 (uqcrc2) subunits in the matrix compartment, thus supporting the conclusion that complex III releases ROS to both sides of the inner membrane during reperfusion. Analysis of ischemic mitochondria indicated a modest reduction from the basal level of complex III PrSO3H detected in the mitochondria of sham control hearts, suggesting that the physiologic hyperoxygenation and ROS overproduction during reperfusion mediated the enhancement of complex III PrSO3H. In conclusion, reperfusion-mediated heme damage with increased PrSO3H controls oxidative injury to complex III and aggravates mitochondrial dysfunction in the post-ischemic heart.
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Affiliation(s)
- Chwen-Lih Chen
- Department of Integrative Medical Sciences, College of Medicine, Northeast Ohio Medical University, Rootstown, OH 44272, United States of America
| | - Patrick T Kang
- Department of Integrative Medical Sciences, College of Medicine, Northeast Ohio Medical University, Rootstown, OH 44272, United States of America
| | - Liwen Zhang
- Campus Chemical Instrument Center, Proteomics and Mass Spectrometry Facility, The Ohio State University, Columbus, OH 43210, United States of America
| | - Kunhong Xiao
- Department of Pharmacology and Chemical Biology and Biomedical Mass Spectrometry Center, University of Pittsburgh, PA 15261, United States of America
| | - Jay L Zweier
- Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, United States of America
| | - William M Chilian
- Department of Integrative Medical Sciences, College of Medicine, Northeast Ohio Medical University, Rootstown, OH 44272, United States of America
| | - Yeong-Renn Chen
- Department of Integrative Medical Sciences, College of Medicine, Northeast Ohio Medical University, Rootstown, OH 44272, United States of America.
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4
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Pacheco R, Quezada SA, Kalergis AM, Becker MI, Ferreira J, De Ioannes AE. Allergens of the urushiol family promote mitochondrial dysfunction by inhibiting the electron transport at the level of cytochromes b and chemically modify cytochrome c 1. Biol Res 2021; 54:35. [PMID: 34711292 PMCID: PMC8554850 DOI: 10.1186/s40659-021-00357-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 10/06/2021] [Indexed: 11/10/2022] Open
Abstract
Background Urushiols are pro-electrophilic haptens that cause severe contact dermatitis mediated by CD8+ effector T-cells and downregulated by CD4+ T-cells. However, the molecular mechanism by which urushiols stimulate innate immunity in the initial stages of this allergic reaction is poorly understood. Here we explore the sub-cellular mechanisms by which urushiols initiate the allergic response. Results Electron microscopy observations of mouse ears exposed to litreol (3-n-pentadecyl-10-enyl-catechol]) showed keratinocytes containing swollen mitochondria with round electron-dense inclusion bodies in the matrix. Biochemical analyses of sub-mitochondrial fractions revealed an inhibitory effect of urushiols on electron flow through the mitochondrial respiratory chain, which requires both the aliphatic and catecholic moieties of these allergens. Moreover, urushiols extracted from poison ivy/oak (mixtures of 3-n-pentadecyl-8,11,13 enyl/3-n-heptadecyl-8,11 enyl catechol) exerted a higher inhibitory effect on mitochondrial respiration than did pentadecyl catechol or litreol, indicating that the higher number of unsaturations in the aliphatic chain, stronger the allergenicity of urushiols. Furthermore, the analysis of radioactive proteins isolated from mitochondria incubated with 3H-litreol, indicated that this urushiol was bound to cytochrome c1. According to the proximity of cytochromes c1 and b, functional evidence indicated the site of electron flow inhibition was within complex III, in between cytochromes bL (cyt b566) and bH (cyt b562). Conclusion Our data provide functional and molecular evidence indicating that the interruption of the mitochondrial electron transport chain constitutes an important mechanism by which urushiols initiates the allergic response. Thus, mitochondria may constitute a source of cellular targets for generating neoantigens involved in the T-cell mediated allergy induced by urushiols. Supplementary Information The online version contains supplementary material available at 10.1186/s40659-021-00357-z.
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Affiliation(s)
- Rodrigo Pacheco
- Laboratorio de Neuroinmunología, Fundación Ciencia & Vida, Santiago, Chile. .,Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile.
| | - Sergio A Quezada
- Cancer Immunology Unit, University College London (UCL) Cancer Institute, London, England, UK
| | - Alexis M Kalergis
- Instituto Milenio de Inmunología e Inmunoterapia, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Departamento de Endocrinología, Facultad de Medicina, Pontificia Universidad Católica, Santiago, Chile
| | - María Inés Becker
- Fundación Ciencia y Tecnología para el Desarrollo (FUCITED), Santiago, Chile.,Department of Research and Development, Biosonda Corporation, Santiago, Chile.,Faculty of Physical and Mathematical Sciences, Department of Chemical Engineering, Biotechnology and Materials, Universidad de Chile, Santiago, Chile
| | - Jorge Ferreira
- Faculty of Medicine, Institute of Biomedical Sciences, Molecular and Clinical Pharmacology Program, Universidad de Chile, Santiago, Chile
| | - Alfredo E De Ioannes
- Department of Research and Development, Biosonda Corporation, Santiago, Chile.,Faculty of Physical and Mathematical Sciences, Department of Chemical Engineering, Biotechnology and Materials, Universidad de Chile, Santiago, Chile.,Faculty of Medicine, Institute of Biomedical Sciences, Molecular and Clinical Pharmacology Program, Universidad de Chile, Santiago, Chile
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5
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Leung SW, Baker PL, Redding KE. Deletion of the cytochrome bc complex from Heliobacterium modesticaldum results in viable but non-phototrophic cells. Photosynth Res 2021; 148:137-152. [PMID: 34236566 DOI: 10.1007/s11120-021-00845-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Accepted: 05/04/2021] [Indexed: 06/13/2023]
Abstract
The heliobacteria, a family of anoxygenic phototrophs, possess the simplest known photosynthetic apparatus. Although they are photoheterotrophs in the light, the heliobacteria can also grow chemotrophically via pyruvate metabolism in the dark. In the heliobacteria, the cytochrome bc complex is responsible for oxidizing menaquinol and reducing cytochrome c553 in the electron flow cycle used for phototrophy. However, there is no known electron acceptor for the mobile cytochrome c553 other than the photochemical reaction center. We have, therefore, hypothesized that the cytochrome bc complex is necessary for phototrophy, but unnecessary for chemotrophic growth in the dark. We used a two-step method for CRISPR-based genome editing in Heliobacterium modesticaldum to delete the genes encoding the four major subunits of the cytochrome bc complex. Genotypic analysis verified the deletion of the petCBDA gene cluster encoding the catalytic components of the complex. Spectroscopic studies revealed that re-reduction of cytochrome c553 after flash-induced photo-oxidation was over 100 times slower in the ∆petCBDA mutant compared to the wild-type. Steady-state levels of oxidized P800 (the primary donor of the photochemical reaction center) were much higher in the ∆petCBDA mutant at every light level, consistent with a limitation in electron flow to the reaction center. The ∆petCBDA mutant was unable to grow phototrophically on acetate plus CO2 but could grow chemotrophically on pyruvate as a carbon source similar to the wild-type strain in the dark. The mutants could be complemented by reintroduction of the petCBDA gene cluster on a plasmid expressed from the clostridial eno promoter.
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Affiliation(s)
- Sabrina W Leung
- School of Molecular Sciences, Arizona State University, 1711 S Rural Rd, Box 871604, Tempe, AZ, 85287-1604, USA
| | - Patricia L Baker
- School of Molecular Sciences, Arizona State University, 1711 S Rural Rd, Box 871604, Tempe, AZ, 85287-1604, USA
| | - Kevin E Redding
- School of Molecular Sciences, Arizona State University, 1711 S Rural Rd, Box 871604, Tempe, AZ, 85287-1604, USA.
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6
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Páleníková P, Harbour ME, Prodi F, Minczuk M, Zeviani M, Ghelli A, Fernández-Vizarra E. Duplexing complexome profiling with SILAC to study human respiratory chain assembly defects. Biochim Biophys Acta Bioenerg 2021; 1862:148395. [PMID: 33600785 DOI: 10.1016/j.bbabio.2021.148395] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 02/03/2021] [Accepted: 02/05/2021] [Indexed: 12/19/2022]
Abstract
Complexome Profiling (CP) combines size separation, by electrophoresis or other means, of native multimeric complexes with protein identification by mass spectrometry (MS). Peptide MS analysis of the multiple fractions in which the sample is separated, results in the creation of protein abundance profiles in function of molecular size, providing a visual output of the assembly status of a group of proteins of interest. Stable isotope labeling by amino acids in cell culture (SILAC) is an established quantitative proteomics technique that allows duplexing in the MS analysis as well as the comparison of relative protein abundances between the samples, which are processed and analyzed together. Combining SILAC and CP permitted the direct comparison of migration and abundance of the proteins present in the mitochondrial respiratory chain complexes in two different samples. This analysis, however, introduced a level of complexity in data processing for which bioinformatic tools had to be developed in order to generate the normalized protein abundance profiles. The advantages and challenges of using of this type of analysis for the characterization of two cell lines carrying pathological variants in MT-CO3 and MT-CYB is reviewed. An additional unpublished example of SILAC-CP of a cell line with an in-frame 18-bp deletion in MT-CYB is presented. In these cells, in contrast to other MT-CYB deficient models, a small proportion of complex III2 is formed and it is found associated with fully assembled complex I. This analysis also revealed a profuse accumulation of assembly intermediates containing complex III subunits UQCR10 and CYC1, as well as a profound early-stage complex IV assembly defect.
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Affiliation(s)
- Petra Páleníková
- Medical Research Council-Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Michael E Harbour
- Medical Research Council-Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Federica Prodi
- Dipartimento di Farmacia e Biotecnologie (FABIT), Università di Bologna, Bologna, Italy
| | - Michal Minczuk
- Medical Research Council-Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Massimo Zeviani
- Medical Research Council-Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Anna Ghelli
- Dipartimento di Farmacia e Biotecnologie (FABIT), Università di Bologna, Bologna, Italy
| | - Erika Fernández-Vizarra
- Medical Research Council-Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK.
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7
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Le Vasseur M, Friedman J, Jost M, Xu J, Yamada J, Kampmann M, Horlbeck MA, Salemi MR, Phinney BS, Weissman JS, Nunnari J. Genome-wide CRISPRi screening identifies OCIAD1 as a prohibitin client and regulatory determinant of mitochondrial Complex III assembly in human cells. eLife 2021; 10:67624. [PMID: 34034859 PMCID: PMC8154037 DOI: 10.7554/elife.67624] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 05/10/2021] [Indexed: 01/01/2023] Open
Abstract
Dysfunction of the mitochondrial electron transport chain (mETC) is a major cause of human mitochondrial diseases. To identify determinants of mETC function, we screened a genome-wide human CRISPRi library under oxidative metabolic conditions with selective inhibition of mitochondrial Complex III and identified ovarian carcinoma immunoreactive antigen (OCIA) domain-containing protein 1 (OCIAD1) as a Complex III assembly factor. We find that OCIAD1 is an inner mitochondrial membrane protein that forms a complex with supramolecular prohibitin assemblies. Our data indicate that OCIAD1 is required for maintenance of normal steady-state levels of Complex III and the proteolytic processing of the catalytic subunit cytochrome c1 (CYC1). In OCIAD1 depleted mitochondria, unprocessed CYC1 is hemylated and incorporated into Complex III. We propose that OCIAD1 acts as an adaptor within prohibitin assemblies to stabilize and/or chaperone CYC1 and to facilitate its proteolytic processing by the IMMP2L protease.
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Affiliation(s)
- Maxence Le Vasseur
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of California, Davis, Davis, United States
| | - Jonathan Friedman
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of California, Davis, Davis, United States.,Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Marco Jost
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, United States.,Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, United States.,Department of Microbiology and Immunology, University of California at San Francisco, San Francisco, United States
| | - Jiawei Xu
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of California, Davis, Davis, United States
| | - Justin Yamada
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of California, Davis, Davis, United States
| | - Martin Kampmann
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, United States.,Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, United States.,Institute for Neurodegenerative Diseases and Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, United States.,Chan-Zuckerberg Biohub, San Francisco, United States
| | - Max A Horlbeck
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, United States.,Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, United States
| | - Michelle R Salemi
- Proteomics Core Facility, University of California, Davis, Davis, United States
| | - Brett S Phinney
- Proteomics Core Facility, University of California, Davis, Davis, United States
| | - Jonathan S Weissman
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, United States.,Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, United States.,Whitehead Institute, Cambridge, United States.,Department of Biology, Massachusetts Institute of Technology, Cambridge, United States
| | - Jodi Nunnari
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of California, Davis, Davis, United States
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8
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Acoba MG, Alpergin ESS, Renuse S, Fernández-Del-Río L, Lu YW, Khalimonchuk O, Clarke CF, Pandey A, Wolfgang MJ, Claypool SM. The mitochondrial carrier SFXN1 is critical for complex III integrity and cellular metabolism. Cell Rep 2021; 34:108869. [PMID: 33730581 PMCID: PMC8048093 DOI: 10.1016/j.celrep.2021.108869] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 01/18/2021] [Accepted: 02/24/2021] [Indexed: 12/13/2022] Open
Abstract
Mitochondrial carriers (MCs) mediate the passage of small molecules across the inner mitochondrial membrane (IMM), enabling regulated crosstalk between compartmentalized reactions. Despite MCs representing the largest family of solute carriers in mammals, most have not been subjected to a comprehensive investigation, limiting our understanding of their metabolic contributions. Here, we functionally characterize SFXN1, a member of the non-canonical, sideroflexin family. We find that SFXN1, an integral IMM protein with an uneven number of transmembrane domains, is a TIM22 complex substrate. SFXN1 deficiency leads to mitochondrial respiratory chain impairments, most detrimental to complex III (CIII) biogenesis, activity, and assembly, compromising coenzyme Q levels. The CIII dysfunction is independent of one-carbon metabolism, the known primary role for SFXN1 as a mitochondrial serine transporter. Instead, SFXN1 supports CIII function by participating in heme and α-ketoglutarate metabolism. Our findings highlight the multiple ways that SFXN1-based amino acid transport impacts mitochondrial and cellular metabolic efficiency.
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Affiliation(s)
- Michelle Grace Acoba
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ebru S Selen Alpergin
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Santosh Renuse
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; McKusick-Nathans Institute of Genetic Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Lucía Fernández-Del-Río
- Department of Chemistry and Biochemistry and Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Ya-Wen Lu
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Oleh Khalimonchuk
- Department of Biochemistry and Nebraska Redox Biology Center, University of Nebraska, Lincoln, NE 68588, USA; Fred & Pamela Buffett Cancer Center, Omaha, NE 68198, USA
| | - Catherine F Clarke
- Department of Chemistry and Biochemistry and Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Akhilesh Pandey
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; McKusick-Nathans Institute of Genetic Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Departments of Pathology and Oncology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Michael J Wolfgang
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Steven M Claypool
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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9
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Wong HS, Mezera V, Dighe P, Melov S, Gerencser AA, Sweis RF, Pliushchev M, Wang Z, Esbenshade T, McKibben B, Riedmaier S, Brand MD. Superoxide produced by mitochondrial site I Q inactivates cardiac succinate dehydrogenase and induces hepatic steatosis in Sod2 knockout mice. Free Radic Biol Med 2021; 164:223-232. [PMID: 33421588 DOI: 10.1016/j.freeradbiomed.2020.12.447] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/24/2020] [Accepted: 12/28/2020] [Indexed: 12/14/2022]
Abstract
Superoxide produced by mitochondria has been implicated in numerous physiologies and pathologies. Eleven different mitochondrial sites that can produce superoxide and/or hydrogen peroxide (O2.-/H2O2) have been identified in vitro, but little is known about their contributions in vivo. We introduce novel variants of S1QELs and S3QELs (small molecules that suppress O2.-/H2O2 production specifically from mitochondrial sites IQ and IIIQo, respectively, without compromising bioenergetics), that are suitable for use in vivo. When administered by intraperitoneal injection, they achieve total tissue concentrations exceeding those that are effective in vitro. We use them to study the engagement of sites IQ and IIIQo in mice lacking functional manganese-superoxide dismutase (SOD2). Lack of SOD2 is expected to elevate superoxide levels in the mitochondrial matrix, and leads to severe pathologies and death about 8 days after birth. Compared to littermate wild-type mice, 6-day-old Sod2-/- mice had significantly lower body weight, lower heart succinate dehydrogenase activity, and greater hepatic lipid accumulation. These pathologies were ameliorated by treatment with a SOD/catalase mimetic, EUK189, confirming previous observations. A 3-day treatment with S1QEL352 decreased the inactivation of cardiac succinate dehydrogenase and hepatic steatosis in Sod2-/- mice. S1QEL712, which has a distinct chemical structure, also decreased hepatic steatosis, confirming that O2.- derived specifically from mitochondrial site IQ is a significant driver of hepatic steatosis in Sod2-/- mice. These findings also demonstrate the ability of these new S1QELs to suppress O2.- production in the mitochondrial matrix in vivo. In contrast, suppressing site IIIQo using S3QEL941 did not protect, suggesting that site IIIQo does not contribute significantly to mitochondrial O2.- production in the hearts or livers of Sod2-/- mice. We conclude that the novel S1QELs are effective in vivo, and that site IQ runs in vivo and is a significant driver of pathology in Sod2-/- mice.
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Affiliation(s)
- Hoi-Shan Wong
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA, 94945, USA
| | - Vojtech Mezera
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA, 94945, USA
| | - Pratiksha Dighe
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA, 94945, USA
| | - Simon Melov
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA, 94945, USA
| | - Akos A Gerencser
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA, 94945, USA
| | - Ramzi F Sweis
- AbbVie Inc., 1 North Waukegan Road, North Chicago, IL, 60064, USA
| | | | - Zhi Wang
- AbbVie Inc., 1 North Waukegan Road, North Chicago, IL, 60064, USA
| | - Tim Esbenshade
- AbbVie Inc., 1 North Waukegan Road, North Chicago, IL, 60064, USA
| | - Bryan McKibben
- AbbVie Inc., 1 North Waukegan Road, North Chicago, IL, 60064, USA
| | | | - Martin D Brand
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA, 94945, USA.
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10
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Abstract
Mitochondria are the powerhouses of the cell. They produce a significant amount of the energy we need to grow, survive and reproduce. The same system that generates energy in the form of ATP also produces Reactive Oxygen Species (ROS). Mitochondrial Reactive Oxygen Species (mtROS) were considered for many years toxic by-products of metabolism, responsible for ageing and many degenerative diseases. Today, we know that mtROS are essential redox messengers required to determine cell fate and maintain cellular homeostasis. Most mtROS are produced by respiratory complex I (CI) and complex III (CIII). How and when CI and CIII produce ROS is determined by the redox state of the Coenzyme Q (CoQ) pool and the proton motive force (pmf) generated during respiration. During ageing, there is an accumulation of defective mitochondria that generate high levels of mtROS. This causes oxidative stress and disrupts redox signalling. Here, we review how mtROS are generated in young and old mitochondria and how CI and CIII derived ROS control physiological and pathological processes. Finally, we discuss why damaged mitochondria amass during ageing as well as methods to preserve mitochondrial redox signalling with age.
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Affiliation(s)
- Filippo Scialo
- Dipartimento di Scienze Mediche Traslazionali, Università della Campania "Luigi Vanvitelli", 80131, Napoli, Italy
| | - Alberto Sanz
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, G12 8QQ, Glasgow, United Kingdom.
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11
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Xia D. Structural snapshots of the cellular folded protein translocation machinery Bcs1. FEBS J 2020; 288:2870-2883. [PMID: 32979284 PMCID: PMC7994207 DOI: 10.1111/febs.15576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 09/05/2020] [Accepted: 09/22/2020] [Indexed: 11/29/2022]
Abstract
Proteins destined to various intra‐ and extra‐cellular locations must traverse membranes most frequently in an unfolded form. When the proteins being translocated need to remain in a folded state, specialized cellular transport machinery is used. One such machine is the membrane‐bound AAA protein Bcs1 (Bcs1), which assists the iron‐sulfur protein, an essential subunit of the respiratory Complex III, across the mitochondrial inner membrane. Recent structure determinations of mouse and yeast Bcs1 in three different nucleotide states reveal its homo‐heptameric association and at least two dramatically different conformations. The apo and ADP‐bound structures are similar, both containing a large substrate‐binding cavity accessible to the mitochondrial matrix space, which contracts by concerted motion of the ATPase domains upon ATP binding, suggesting that bound substrate could then be pushed across the membrane. ATP hydrolysis drives substrate release and resets Bcs1 conformation back to the apo/ADP form. These structures shed new light on the mechanism of folded protein translocation across a membrane, provide better understanding on the assembly process of the respiratory Complex III, and correlate clinical presentations of disease‐associated mutations with their locations in the 3D structure.
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Affiliation(s)
- Di Xia
- Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
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12
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Liu R, Cao SK, Sayyed A, Yang HH, Zhao J, Wang X, Jia RX, Sun F, Tan BC. The DYW-subgroup pentatricopeptide repeat protein PPR27 interacts with ZmMORF1 to facilitate mitochondrial RNA editing and seed development in maize. J Exp Bot 2020; 71:5495-5505. [PMID: 32531050 DOI: 10.1093/jxb/eraa273] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 06/09/2020] [Indexed: 05/02/2023]
Abstract
C-to-U RNA editing in plant mitochondria requires the participation of many nucleus-encoded factors, most of which are pentatricopeptide repeat (PPR) proteins. There is a large number of PPR proteins and the functions many of them are unknown. Here, we report a mitochondrion-localized DYW-subgroup PPR protein, PPR27, which functions in the editing of multiple mitochondrial transcripts in maize. The ppr27 mutant is completely deficient in C-to-U editing at the ccmFN-1357 and rps3-707 sites, and editing at six other sites is substantially reduced. The lack of editing at ccmFN-1357 causes a deficiency of CcmFN protein. As CcmFN functions in the maturation pathway of cytochrome proteins that are subunits of mitochondrial complex III, its deficiency results in an absence of cytochrome c1 and cytochrome c proteins. Consequently, the assembly of mitochondrial complex III and super-complex I+III2 is decreased, which impairs the electron transport chain and respiration, leading to arrests in embryogenesis and endosperm development in ppr27. In addition, PPR27 was found to physically interact with ZmMORF1, which interacts with ZmMORF8, suggesting that these three proteins may facilitate C-to-U RNA editing via the formation of a complex in maize mitochondria. This RNA editing is essential for complex III assembly and seed development in maize.
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Affiliation(s)
- Rui Liu
- Key Laboratory of Plant Development and Environment Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, China
| | - Shi-Kai Cao
- Key Laboratory of Plant Development and Environment Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, China
| | - Aqib Sayyed
- Key Laboratory of Plant Development and Environment Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, China
| | - Huan-Huan Yang
- Key Laboratory of Plant Development and Environment Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, China
| | - Jiao Zhao
- Key Laboratory of Plant Development and Environment Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, China
| | - Xiaomin Wang
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Ru-Xue Jia
- Key Laboratory of Plant Development and Environment Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, China
| | - Feng Sun
- Key Laboratory of Plant Development and Environment Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, China
| | - Bao-Cai Tan
- Key Laboratory of Plant Development and Environment Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, China
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13
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Pardo Andreu GL, Reis FZD, González-Durruthy M, Hernández RD, D'Vries RF, Vanden Berghe W, Alberici LC. Rapanone, a naturally occurring benzoquinone, inhibits mitochondrial respiration and induces HepG2 cell death. Toxicol In Vitro 2020; 63:104737. [PMID: 31756542 DOI: 10.1016/j.tiv.2019.104737] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 11/15/2019] [Accepted: 11/18/2019] [Indexed: 01/26/2023]
Abstract
Rapanone is a natural occurring benzoquinone with several biological effects including unclear cytotoxic mechanisms. Here we addressed if mitochondria are involved in the cytotoxicity of rapanone towards cancer cells by employing hepatic carcinoma (HepG2) cells and isolated rat liver mitochondria. In the HepG2, rapanone (20-40 μM) induced a concentration-dependent mitochondrial membrane potential dissipation, ATP depletion, hydrogen peroxide generation and, phosphatidyl serine externalization; the latter being indicative of apoptosis induction. Rapanone toxicity towards primary rats hepatocytes (IC50 = 35.58 ± 1.50 μM) was lower than that found for HepG2 cells (IC50 = 27.89 ± 0.75 μM). Loading of isolated mitochondria with rapanone (5-20 μM) caused a concentration-dependent inhibition of phosphorylating and uncoupled respirations supported by complex I (glutamate and malate) or the complex II (succinate) substrates, being the latter eliminated by complex IV substrate (TMPD/ascorbate). Rapanone also dissipated mitochondrial membrane potential, depleted ATP content, released Ca2+ from Ca2+-loaded mitochondria, increased ROS generation, cytochrome c release and membrane fluidity. Further analysis demonstrated that rapanone prevented the cytochrome c reduction in the presence of decylbenzilquinol, identifying complex III as the site of its inhibitory action. Computational docking results of rapanone to cytochrome bc1 (Cyt bc1) complex from the human sources found spontaneous thermodynamic processes for the quinone-Qo and Qi binding interactions, supporting the experimental in vitro assays. Collectively, these observations suggest that rapanone impairs mitochondrial respiration by inhibiting electron transport chain at Complex III and promotes mitochondrial dysfunction. This property is potentially involved in rapanone toxicity on cancer cells.
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14
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Shan W, Li J, Xu W, Li H, Zuo Z. Critical role of UQCRC1 in embryo survival, brain ischemic tolerance and normal cognition in mice. Cell Mol Life Sci 2019; 76:1381-96. [PMID: 30666338 DOI: 10.1007/s00018-019-03007-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 12/21/2018] [Accepted: 01/08/2019] [Indexed: 12/17/2022]
Abstract
Ubiquinol cytochrome c reductase core protein I (UQCRC1) is a component of the complex III in the respiratory chain. Its biological functions are unknown. Here, we showed that knockout of UQCRC1 led to embryonic lethality. Disrupting one UQCRC1 allele in mice (heterozygous mice) of both sexes did not affect their growth but reduced UQCRC1 mRNA and protein in the brain. These mice had decreased complex III formation, complex III activity and ATP content in the brain at baseline. They developed worsened neurological outcome after brain ischemia/hypoxia or focal brain ischemia compared with wild-type mice. The ischemic cerebral cortex of the heterozygous mice had decreased mitochondrial membrane potential and ATP content as well as increased free radicals. Also, the heterozygous mice performed poorly in the Barnes maze and novel object recognition tests. Finally, UQCRC1 was expressed abundantly in neurons and astrocytes. These results suggest a critical role of UQCRC1 in embryo survival. UQCRC1 may also be important by forming the complex III to maintain normal brain ischemic tolerance, learning and memory.
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15
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Francia F, Khalfaoui-Hassani B, Lanciano P, Musiani F, Noodleman L, Venturoli G, Daldal F. The cytochrome b lysine 329 residue is critical for ubihydroquinone oxidation and proton release at the Q o site of bacterial cytochrome bc 1. Biochim Biophys Acta Bioenerg 2018; 1860:167-179. [PMID: 30550726 DOI: 10.1016/j.bbabio.2018.12.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 12/06/2018] [Accepted: 12/07/2018] [Indexed: 11/16/2022]
Abstract
The ubihydroquinone:cytochrome (cyt) c oxidoreductase (or cyt bc1) is an important enzyme for photosynthesis and respiration. In bacteria like Rhodobacter capsulatus, this membrane complex has three subunits, the iron‑sulfur protein (ISP) with its Fe2S2 cluster, cyt c1 and cyt b, forming two catalytic domains, the Qo (hydroquinone (QH2) oxidation) and Qi (quinone (Q) reduction) sites. At the Qo site, the electron transfer pathways originating from QH2 oxidation are known, but their associated proton release routes are less well defined. Earlier, we demonstrated that the His291 of cyt b is important for this latter process. In this work, using the bacterial cyt bc1 and site directed mutagenesis, we show that Lys329 of cyt b is also critical for electron and proton transfer at the Qo site. Of the mutants examined, Lys329Arg was photosynthesis proficient and had quasi-wild type cyt bc1 activity. In contrast, the Lys329Ala and Lys329Asp were photosynthesis-impaired and contained defective but assembled cyt bc1. In particular, the bifurcated electron transfer and associated proton(s) release reactions occurring during QH2 oxidation were drastically impaired in Lys329Asp mutant. Furthermore, in silico docking studies showed that in this mutant the location and the H-bonding network around the Fe2S2 cluster of ISP on cyt b surface was different than the wild type enzyme. Based on these experimental findings and theoretical considerations, we propose that the presence of a positive charge at position 329 of cyt b is critical for efficient electron transfer and proton release for QH2 oxidation at the Qo site of cyt bc1.
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Affiliation(s)
- Francesco Francia
- Dipartimento di Farmacia e Biotecnologie, FaBiT, Università di Bologna, 40126 Bologna, Italy
| | | | - Pascal Lanciano
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Francesco Musiani
- Dipartimento di Farmacia e Biotecnologie, FaBiT, Università di Bologna, 40126 Bologna, Italy
| | - Louis Noodleman
- The Scripps Research Institute, Department of Integrative Structural and Computational Biology, La Jolla, CA 92037, USA
| | - Giovanni Venturoli
- Dipartimento di Farmacia e Biotecnologie, FaBiT, Università di Bologna, 40126 Bologna, Italy; Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia (CNISM), Dipartimento di Fisica, Università di Bologna, 40127 Bologna, Italy
| | - Fevzi Daldal
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.
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16
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Tian S, Chen H, Tan W. Targeting mitochondrial respiration as a therapeutic strategy for cervical cancer. Biochem Biophys Res Commun 2018; 499:1019-1024. [PMID: 29630860 DOI: 10.1016/j.bbrc.2018.04.042] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 04/05/2018] [Indexed: 11/28/2022]
Abstract
Targeting mitochondrial respiration has been documented as an effective therapeutic strategy in cancer. However, the impact of mitochondrial respiration inhibition on cervical cancer cells are not well elucidated. Using a panel of cervical cancer cell lines, we show that an existing drug atovaquone is active against the cervical cancer cells with high profiling of mitochondrial biogenesis. Atovaquone inhibited proliferation and induced apoptosis with varying efficacy among cervical cancer cell lines regardless of HPV infection, cellular origin and their sensitivity to paclitaxel. We further demonstrated that atovaquone acts on cervical cancer cells via inhibiting mitochondrial respiration. In particular, atovaquone specifically inhibited mitochondrial complex III but not I, II or IV activity, leading to respiration inhibition and energy crisis. Importantly, we found that the different sensitivity of cervical cancer cell lines to atovaquone were due to their differential level of mitochondrial biogenesis and dependency to mitochondrial respiration. In addition, we demonstrated that the in vitro observations were translatable to in vivo cervical cancer xenograft mouse model. Our findings suggest that the mitochondrial biogenesis varies among patients with cervical cancer. Our work also suggests that atovaquone is a useful addition to cervical cancer treatment, particularly to those with high dependency on mitochondrial respiration.
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Affiliation(s)
- Shenglan Tian
- Department of Anesthesia and Pain Management, Wuhan University of Science and Technology Hospital, Wuhan, Hubei, PR China
| | - Heng Chen
- Ultrasound Department, Wuhan University of Science and Technology Hospital, Wuhan, Hubei, PR China
| | - Wei Tan
- Chief physician/Professor, Wuhan University of Science and Technology Hospital, Wuhan, Hubei, PR China.
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17
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Abstract
Mitochondria are the power stations of the eukaryotic cell, using the energy released by the oxidation of glucose and other sugars to produce ATP. Electrons are transferred from NADH, produced in the citric acid cycle in the mitochondrial matrix, to oxygen by a series of large protein complexes in the inner mitochondrial membrane, which create a transmembrane electrochemical gradient by pumping protons across the membrane. The flow of protons back into the matrix via a proton channel in the ATP synthase leads to conformational changes in the nucleotide binding pockets and the formation of ATP. The three proton pumping complexes of the electron transfer chain are NADH-ubiquinone oxidoreductase or complex I, ubiquinone-cytochrome c oxidoreductase or complex III, and cytochrome c oxidase or complex IV. Succinate dehydrogenase or complex II does not pump protons, but contributes reduced ubiquinone. The structures of complex II, III and IV were determined by x-ray crystallography several decades ago, but complex I and ATP synthase have only recently started to reveal their secrets by advances in x-ray crystallography and cryo-electron microscopy. The complexes I, III and IV occur to a certain extent as supercomplexes in the membrane, the so-called respirasomes. Several hypotheses exist about their function. Recent cryo-electron microscopy structures show the architecture of the respirasome with near-atomic detail. ATP synthase occurs as dimers in the inner mitochondrial membrane, which by their curvature are responsible for the folding of the membrane into cristae and thus for the huge increase in available surface that makes mitochondria the efficient energy plants of the eukaryotic cell.
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Affiliation(s)
- Joana S Sousa
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Edoardo D'Imprima
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Janet Vonck
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany.
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18
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Alber NA, Sivanesan H, Vanlerberghe GC. The occurrence and control of nitric oxide generation by the plant mitochondrial electron transport chain. Plant Cell Environ 2017; 40:1074-1085. [PMID: 27987212 DOI: 10.1111/pce.12884] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 12/02/2016] [Accepted: 12/05/2016] [Indexed: 05/03/2023]
Abstract
The plant mitochondrial electron transport chain (ETC) is bifurcated such that electrons from ubiquinol are passed to oxygen via the usual cytochrome path or through alternative oxidase (AOX). We previously showed that knockdown of AOX in transgenic tobacco increased leaf concentrations of nitric oxide (NO), implying that an activity capable of generating NO had been effected. Here, we identify the potential source of this NO. Treatment of leaves with antimycin A (AA, Qi -site inhibitor of Complex III) increased NO amount more than treatment with myxothiazol (Myxo, Qo -site inhibitor) despite both being equally effective at inhibiting respiration. Comparison of nitrate-grown wild-type with AOX knockdown and overexpression plants showed a negative correlation between AOX amount and NO amount following AA. Further, Myxo fully negated the ability of AA to increase NO amount. With ammonium-grown plants, neither AA nor Myxo strongly increased NO amount in any plant line. When these leaves were supplied with nitrite alongside the AA or Myxo, then the inhibitor effects across lines mirrored that of nitrate-grown plants. Hence the ETC, likely the Q-cycle of Complex III generates NO from nitrite, and AOX reduces this activity by acting as a non-energy-conserving electron sink upstream of Complex III.
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Affiliation(s)
- Nicole A Alber
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C1A4, Canada
| | - Hampavi Sivanesan
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C1A4, Canada
| | - Greg C Vanlerberghe
- Department of Biological Sciences and Department of Cell and Systems Biology, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C1A4, Canada
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19
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Maio N, Kim KS, Singh A, Rouault TA. A Single Adaptable Cochaperone-Scaffold Complex Delivers Nascent Iron-Sulfur Clusters to Mammalian Respiratory Chain Complexes I-III. Cell Metab 2017; 25:945-953.e6. [PMID: 28380382 DOI: 10.1016/j.cmet.2017.03.010] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 01/27/2017] [Accepted: 03/15/2017] [Indexed: 12/31/2022]
Abstract
The iron-sulfur (Fe-S) cluster of the Rieske protein, UQCRFS1, is essential for Complex III (CIII) activity, though the mechanism for Fe-S cluster transfer has not previously been elucidated. Recent studies have shown that the co-chaperone HSC20, essential for Fe-S cluster biogenesis of SDHB, directly binds LYRM7, formerly described as a chaperone that stabilizes UQCRFS1 prior to its insertion into CIII. Here we report that a transient subcomplex involved in CIII assembly, composed of LYRM7 bound to UQCRFS1, interacts with components of an Fe-S transfer complex, consisting of HSC20, its cognate chaperone HSPA9, and the holo-scaffold ISCU. Binding of HSC20 to the LYR motif of LYRM7 in a pre-assembled UQCRFS1-LYRM7 intermediate in the mitochondrial matrix facilitates Fe-S cluster transfer to UQCRFS1. The five Fe-S cluster subunits of Complex I also interact with HSC20 to acquire their clusters, highlighting the crucial role of HSC20 in the assembly of the mitochondrial respiratory chain.
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Affiliation(s)
- Nunziata Maio
- Molecular Medicine Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Ki Soon Kim
- Molecular Medicine Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Anamika Singh
- Molecular Medicine Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Tracey A Rouault
- Molecular Medicine Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, 9000 Rockville Pike, Bethesda, MD 20892, USA.
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20
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Abstract
Mitochondria are the prime source of ATP in cardiomyocytes. Impairment of mitochondrial metabolism results in damage to existing proteins and DNA. Such deleterious effects are part and parcel of the aging process, reducing the ability of cardiomyocytes to counter stress, such as myocardial infarction and consequent reperfusion. In such conditions, mitochondria in the heart of aged individuals exhibit decreased oxidative phosphorylation, decreased ATP production, and increased net reactive oxygen species production; all of these effects are independent of the decrease in number of mitochondria that occurs in these situations. Rather than being associated with the mitochondrial population in toto, these defects are almost exclusively confined to those organelles positioned between myofibrils (interfibrillar mitochondria). It is in complex III and IV where these dysfunctional aspects are manifested. In an apparent effort to correct mitochondrial metabolic defects, affected organelles are to some extent eliminated by mitophagy; at the same time, new, unaffected organelles are generated by fission of mitochondria. Because these cardiac health issues are localized to specific mitochondria, these organelles offer potential targets for therapeutic approaches that could favorably affect the aging process in heart.
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Anastasio N, Tarailo-Graovac M, Al-Khalifah R, Legault L, Drogemoller B, Ross CJD, Wasserman WW, van Karnebeek C, Buhas D. Mitochondrial Complex III Deficiency with Ketoacidosis and Hyperglycemia Mimicking Neonatal Diabetes. JIMD Rep 2016; 31:57-62. [PMID: 27074787 DOI: 10.1007/8904_2016_557] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 03/10/2016] [Accepted: 03/15/2016] [Indexed: 12/12/2022] Open
Abstract
Hyperglycemia is a rare presenting symptom of mitochondrial disorders. We report a case of a young girl who presented shortly after birth with ketoacidosis, hyperlactatemia, hyperammonemia, and insulin-responsive hyperglycemia. Initial metabolic work-up suggested mitochondrial dysfunction. Given our patient's unusual presentation, whole-exome sequencing (WES) was performed on the parent-offspring trio. The patient was homozygous for the c.643C>T (p.Leu215Phe) variant in CYC1, a nuclear gene which encodes cytochrome c 1 , a subunit of respiratory chain complex III. Variants in this gene have only been previously reported in two patients with similar presentation, one of whom carries the same variant as our patient who is also of Sri Lankan origin.Primary complex III deficiencies are rare and its phenotypes can vary significantly, even among patients with the same genotype.
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Affiliation(s)
- Natascia Anastasio
- Department of Medical Genetics, McGill University, 1001 Boulevard Décarie, Montréal, QC, Canada, H4A 3J1.
| | - Maja Tarailo-Graovac
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, 950 West 28th Avenue, Vancouver, BC, Canada, V5Z 4H4
| | - Reem Al-Khalifah
- Division of Pediatrics Endocrinology, McGill University, 1001 Boulevard Décarie, Montréal, QC, Canada, H4A 3J1.,Division of Pediatric Endocrinology, King Saud University, Riyadh, Saudi Arabia
| | - Laurent Legault
- Division of Pediatrics Endocrinology, McGill University, 1001 Boulevard Décarie, Montréal, QC, Canada, H4A 3J1
| | - Britt Drogemoller
- Child & Family Research Institute, University of British Columbia, 938 West 28th Avenue, Vancouver, BC, Canada, V5Z 4H4
| | - Colin J D Ross
- Child & Family Research Institute, University of British Columbia, 950 West 28th Avenue, A3-216, Vancouver, BC, Canada, V5Z 4H4
| | - Wyeth W Wasserman
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child & Family Research Institute, University of British Columbia, 950 West 28th Avenue, Vancouver, BC, Canada, V5Z 4H4
| | - Clara van Karnebeek
- Department of Pediatrics, Centre for Molecular Medicine and Therapeutics, Child & Family Research Institute, University of British Columbia, 950 West 28th Avenue, Vancouver, BC, Canada, V5Z 4H4
| | - Daniela Buhas
- Department of Medical Genetics, McGill University, 1001 Boulevard Décarie, Montréal, QC, Canada, H4A 3J1
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22
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Yu Z, Zhang Y, Liu N, Yuan J, Lin L, Zhuge Q, Xiao J, Wang X. Roles of Neuroglobin Binding to Mitochondrial Complex III Subunit Cytochrome c1 in Oxygen-Glucose Deprivation-Induced Neurotoxicity in Primary Neurons. Mol Neurobiol 2015; 53:3249-3257. [PMID: 26050086 DOI: 10.1007/s12035-015-9273-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 05/28/2015] [Indexed: 12/16/2022]
Abstract
Neuroglobin (Ngb) is a tissue globin specifically expressed in brain neurons. Recent studies by our laboratory and others have demonstrated that Ngb is protective against stroke and related neurological disorders, but the mechanisms remain poorly understood. We previously identified cytochrome c1 (Cyc1) as an Ngb-interacting molecule by yeast two-hybrid screening. Cyc1 is a subunit of mitochondria complex III, which is a component of mitochondrial respiratory chain and a major source of reactive oxygen species (ROS) production under both physiological and pathological conditions. In this study, we for the first time defined Ngb-Cyc1 binding, and investigated its roles in oxygen-glucose deprivation (OGD)/reoxygenation-induced neurotoxicity and ROS production in primary neurons. Immunocytochemistry and co-immunoprecipitation validated Ngb-Cyc1 binding, which was significantly increased by OGD and Ngb overexpression. We found 4 h OGD with/without 4 h reoxygenation significantly increased complex III activity, but this activity elevation was significantly attenuated in three groups of neurons: Ngb overexpression, specific complex III inhibitor stigmatellin, or stigmatellin plus Ngb overexpression, whereas there was no significant differences between these three groups, suggesting Ngb-Cyc1 binding may function in suppressing OGD-mediated complex III activity elevation. Importantly, these three groups of neurons also showed significant decreases in OGD-induced superoxide anion generation and neurotoxicity. These results suggest that Ngb can bind to mitochondrial complex III subunit Cyc1, leading to suppression of OGD-mediated complex III activity and subsequent ROS production elevation, and eventually reduction of OGD-induced neurotoxicity. This molecular signaling cascade may be at least part of the mechanisms of Ngb neuroprotection against OGD-induced neurotoxicity.
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Affiliation(s)
- Zhanyang Yu
- Department of Neurosurgery, The First Affiliated Hospital, College of Pharmacy, Wenzhou Medical University, Wenzhou, Zhejiang, 325000, China. .,Neuroprotection Research Laboratory, Departments of Neurology and Radiology, Massachusetts General Hospital, and Program in Neuroscience, Harvard Medical School, 149 13th Street, Room 2411A, Charlestown, MA, 02129, USA.
| | - Yu Zhang
- Department of Neurosurgery, The First Affiliated Hospital, College of Pharmacy, Wenzhou Medical University, Wenzhou, Zhejiang, 325000, China
| | - Ning Liu
- Key Laboratory of Protein Biochemistry and Developmental Biology of State Education Ministry, College of Life Sciences, Hunan Normal University, Changsha, Hunan, 410081, China
| | - Jing Yuan
- Key Laboratory of Protein Biochemistry and Developmental Biology of State Education Ministry, College of Life Sciences, Hunan Normal University, Changsha, Hunan, 410081, China.,Neuroprotection Research Laboratory, Departments of Neurology and Radiology, Massachusetts General Hospital, and Program in Neuroscience, Harvard Medical School, 149 13th Street, Room 2411A, Charlestown, MA, 02129, USA
| | - Li Lin
- Department of Neurosurgery, The First Affiliated Hospital, College of Pharmacy, Wenzhou Medical University, Wenzhou, Zhejiang, 325000, China
| | - Qichuan Zhuge
- Department of Neurosurgery, The First Affiliated Hospital, College of Pharmacy, Wenzhou Medical University, Wenzhou, Zhejiang, 325000, China
| | - Jian Xiao
- Department of Neurosurgery, The First Affiliated Hospital, College of Pharmacy, Wenzhou Medical University, Wenzhou, Zhejiang, 325000, China
| | - Xiaoying Wang
- Neuroprotection Research Laboratory, Departments of Neurology and Radiology, Massachusetts General Hospital, and Program in Neuroscience, Harvard Medical School, 149 13th Street, Room 2411A, Charlestown, MA, 02129, USA.
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23
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Bleier L, Wittig I, Heide H, Steger M, Brandt U, Dröse S. Generator-specific targets of mitochondrial reactive oxygen species. Free Radic Biol Med 2015; 78:1-10. [PMID: 25451644 DOI: 10.1016/j.freeradbiomed.2014.10.511] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 10/13/2014] [Accepted: 10/14/2014] [Indexed: 10/24/2022]
Abstract
To understand the role of reactive oxygen species (ROS) in oxidative stress and redox signaling it is necessary to link their site of generation to the oxidative modification of specific targets. Here we have studied the selective modification of protein thiols by mitochondrial ROS that have been implicated as deleterious agents in a number of degenerative diseases and in the process of biological aging, but also as important players in cellular signal transduction. We hypothesized that this bipartite role might be based on different generator sites for "signaling" and "damaging" ROS and a directed release into different mitochondrial compartments. Because two main mitochondrial ROS generators, complex I (NADH:ubiquinone oxidoreductase) and complex III (ubiquinol:cytochrome c oxidoreductase; cytochrome bc1 complex), are known to predominantly release superoxide and the derived hydrogen peroxide (H2O2) into the mitochondrial matrix and the intermembrane space, respectively, we investigated whether these ROS generators selectively oxidize specific protein thiols. We used redox fluorescence difference gel electrophoresis analysis to identify redox-sensitive targets in the mitochondrial proteome of intact rat heart mitochondria. We observed that the modified target proteins were distinctly different when complex I or complex III was employed as the source of ROS. These proteins are potential targets involved in mitochondrial redox signaling and may serve as biomarkers to study the generator-dependent dual role of mitochondrial ROS in redox signaling and oxidative stress.
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Affiliation(s)
- Lea Bleier
- Molecular Bioenergetics Group, Goethe-University, D-60590 Frankfurt am Main, Germany
| | - Ilka Wittig
- Molecular Bioenergetics Group, Goethe-University, D-60590 Frankfurt am Main, Germany; Functional Proteomics, SFB815 Core Unit, Medical School, Goethe-University, D-60590 Frankfurt am Main, Germany
| | - Heinrich Heide
- Molecular Bioenergetics Group, Goethe-University, D-60590 Frankfurt am Main, Germany
| | - Mirco Steger
- Molecular Bioenergetics Group, Goethe-University, D-60590 Frankfurt am Main, Germany
| | - Ulrich Brandt
- Molecular Bioenergetics Group, Goethe-University, D-60590 Frankfurt am Main, Germany; Cluster of Excellence Frankfurt "Macromolecular Complexes," Goethe-University, D-60590 Frankfurt am Main, Germany; Radboud University Medical Center, Nijmegen Center for Mitochondrial Disorders, 6500 GA Nijmegen, The Netherlands
| | - Stefan Dröse
- Molecular Bioenergetics Group, Goethe-University, D-60590 Frankfurt am Main, Germany; Clinic of Anaesthesiology, Intensive Care Medicine and Pain Therapy, Goethe-University Hospital, Frankfurt am Main, Germany.
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24
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Bharadwaj MS, Zhou Y, Molina AJ, Criswell T, Lu B. Examination of bioenergetic function in the inner mitochondrial membrane peptidase 2-like (Immp2l) mutant mice. Redox Biol 2014; 2:1008-15. [PMID: 25460737 PMCID: PMC4215389 DOI: 10.1016/j.redox.2014.08.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 08/14/2014] [Accepted: 08/25/2014] [Indexed: 11/17/2022] Open
Abstract
Inner mitochondrial membrane peptidase 2-like (IMMP2L) protein is a mitochondrial inner membrane peptidase that cleaves the signal peptide sequences of cytochrome c1 (CYC1) and mitochondrial glycerol phosphate dehydrogenase (GPD2). Immp2l mutant mice show infertility and early signs of aging. It is unclear whether mitochondrial respiratory deficiency underlies this phenotype. Here we show that the intermediate forms of GPD2 and CYC1 have normal expression levels and enzymatic function in Immp2l mutants. Mitochondrial respiration is not diminished in isolated mitochondria and cells from mutant mice. Our data suggest that respiratory deficiency is not the cause of the observed Immp2l mutant phenotypes. Expression of IMMP2L substrates CYC1 and GPD2 is not affected in Immp2l mutant mice. Mitochondria of mutant mice have normal complex III and GPD2 activities. Mitochondrial respiration of mutant mice is not diminished.
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Affiliation(s)
- Manish S Bharadwaj
- Section on Gerontology and Geriatric Medicine, Wake Forest University Health Sciences, Department of Internal Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA
| | - Yu Zhou
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Medical Center Boulevard, Winston-Salem, NC 27157, USA
| | - Anthony J Molina
- Section on Gerontology and Geriatric Medicine, Wake Forest University Health Sciences, Department of Internal Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA
| | - Tracy Criswell
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Medical Center Boulevard, Winston-Salem, NC 27157, USA
| | - Baisong Lu
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Medical Center Boulevard, Winston-Salem, NC 27157, USA.
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25
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Orr AL, Ashok D, Sarantos MR, Shi T, Hughes RE, Brand MD. Inhibitors of ROS production by the ubiquinone-binding site of mitochondrial complex I identified by chemical screening. Free Radic Biol Med 2013; 65:1047-1059. [PMID: 23994103 PMCID: PMC4321955 DOI: 10.1016/j.freeradbiomed.2013.08.170] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 08/12/2013] [Accepted: 08/16/2013] [Indexed: 12/21/2022]
Abstract
Mitochondrial production of reactive oxygen species is often considered an unavoidable consequence of aerobic metabolism and currently cannot be manipulated without perturbing oxidative phosphorylation. Antioxidants are widely used to suppress effects of reactive oxygen species after formation, but they can never fully prevent immediate effects at the sites of production. To identify site-selective inhibitors of mitochondrial superoxide/H2O2 production that do not interfere with mitochondrial energy metabolism, we developed a robust small-molecule screen and secondary profiling strategy. We describe the discovery and characterization of a compound (N-cyclohexyl-4-(4-nitrophenoxy)benzenesulfonamide; CN-POBS) that selectively inhibits superoxide/H2O2 production from the ubiquinone-binding site of complex I (site I(Q)) with no effects on superoxide/H2O2 production from other sites or on oxidative phosphorylation. Structure/activity studies identified a core structure that is important for potency and selectivity for site I(Q). By employing CN-POBS in mitochondria respiring on NADH-generating substrates, we show that site I(Q) does not produce significant amounts of superoxide/H2O2 during forward electron transport on glutamate plus malate. Our screening platform promises to facilitate further discovery of direct modulators of mitochondrially derived oxidative damage and advance our ability to understand and manipulate mitochondrial reactive oxygen species production under both normal and pathological conditions.
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Affiliation(s)
- Adam L Orr
- Buck Institute for Research on Aging, Novato, CA 94945, USA.
| | - Deepthi Ashok
- Buck Institute for Research on Aging, Novato, CA 94945, USA
| | | | - Tong Shi
- Buck Institute for Research on Aging, Novato, CA 94945, USA
| | | | - Martin D Brand
- Buck Institute for Research on Aging, Novato, CA 94945, USA
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26
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Perevoshchikova IV, Quinlan CL, Orr AL, Gerencser AA, Brand MD. Sites of superoxide and hydrogen peroxide production during fatty acid oxidation in rat skeletal muscle mitochondria. Free Radic Biol Med 2013; 61:298-309. [PMID: 23583329 PMCID: PMC3871980 DOI: 10.1016/j.freeradbiomed.2013.04.006] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2012] [Revised: 02/01/2013] [Accepted: 04/05/2013] [Indexed: 12/22/2022]
Abstract
H2O2 production by skeletal muscle mitochondria oxidizing palmitoylcarnitine was examined under two conditions: the absence of respiratory chain inhibitors and the presence of myxothiazol to inhibit complex III. Without inhibitors, respiration and H2O2 production were low unless carnitine or malate was added to limit acetyl-CoA accumulation. With palmitoylcarnitine alone, H2O2 production was dominated by complex II (44% from site IIF in the forward reaction); the remainder was mostly from complex I (34%, superoxide from site IF). With added carnitine, H2O2 production was about equally shared between complexes I, II, and III. With added malate, it was 75% from complex III (superoxide from site IIIQo) and 25% from site IF. Thus complex II (site IIF in the forward reaction) is a major source of H2O2 production during oxidation of palmitoylcarnitine ± carnitine. Under the second condition (myxothiazol present to keep ubiquinone reduced), the rates of H2O2 production were highest in the presence of palmitoylcarnitine ± carnitine and were dominated by complex II (site IIF in the reverse reaction). About half the rest was from site IF, but a significant portion, ∼40pmol H2O2·min(-1)·mg protein(-1), was not from complex I, II, or III and was attributed to the proteins of β-oxidation (electron-transferring flavoprotein (ETF) and ETF-ubiquinone oxidoreductase). The maximum rate from the ETF system was ∼200pmol H2O2·min(-1)·mg protein(-1) under conditions of compromised antioxidant defense and reduced ubiquinone pool. Thus complex II and the ETF system both contribute to H2O2 productionduring fatty acid oxidation under appropriate conditions.
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Affiliation(s)
| | | | - Adam L Orr
- Buck Institute for Research on Aging, Novato, CA 94945, USA
| | | | - Martin D Brand
- Buck Institute for Research on Aging, Novato, CA 94945, USA
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27
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Berry EA, De Bari H, Huang LS. Unanswered questions about the structure of cytochrome bc1 complexes. Biochim Biophys Acta 2013; 1827:1258-77. [PMID: 23624176 DOI: 10.1016/j.bbabio.2013.04.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 03/13/2013] [Accepted: 04/16/2013] [Indexed: 11/25/2022]
Abstract
X-ray crystal structures of bc1 complexes obtained over the last 15 years have provided a firm structural basis for our understanding of the complex. For the most part there is good agreement between structures from different species, different crystal forms, and with different inhibitors bound. In this review we focus on some of the remaining unexplained differences, either between the structures themselves or the interpretations of the structural observations. These include the structural basis for the motion of the Rieske iron-sulfur protein in response to inhibitors, a possible conformational change involving tyrosine132 of cytochrome (cyt) b, the presence of cis-peptides at the beginnings of transmembrane helices C, E, and H, the structural insight into the function of the so-called "Core proteins", different modelings of the retained signal peptide, orientation of the low-potential heme b, and chirality of the Met ligand to heme c1. This article is part of a Special Issue entitled: Respiratory complex III and related bc complexes.
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Affiliation(s)
- Edward A Berry
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA.
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28
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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. Biochim Biophys Acta 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] [What about the content of this article? (0)] [Affiliation(s)] [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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29
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Bleier L, Dröse S. Superoxide generation by complex III: from mechanistic rationales to functional consequences. Biochim Biophys Acta 2012; 1827:1320-31. [PMID: 23269318 DOI: 10.1016/j.bbabio.2012.12.002] [Citation(s) in RCA: 231] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 12/05/2012] [Accepted: 12/12/2012] [Indexed: 01/21/2023]
Abstract
Apart from complex I (NADH:ubiquinone oxidoreductase) the mitochondrial cytochrome bc1 complex (complex III; ubiquinol:cytochrome c oxidoreductase) has been identified as the main producer of superoxide and derived reactive oxygen species (ROS) within the mitochondrial respiratory chain. Mitochondrial ROS are generally linked to oxidative stress, aging and other pathophysiological settings like in neurodegenerative diseases. However, ROS produced at the ubiquinol oxidation center (center P, Qo site) of complex III seem to have additional physiological functions as signaling molecules during cellular processes like the adaptation to hypoxia. The molecular mechanism of superoxide production that is mechanistically linked to the electron bifurcation during ubiquinol oxidation is still a matter of debate. Some insight comes from extensive kinetic studies with mutated complexes from yeast and bacterial cytochrome bc1 complexes. This review is intended to bridge the gap between those mechanistic studies and investigations on complex III ROS in cellular signal transduction and highlights factors that impact superoxide generation. This article is part of a Special Issue entitled: Respiratory complex III and related bc complexes.
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Affiliation(s)
- Lea Bleier
- Molecular Bioenergetics Group, Medical School, Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany
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