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Gélinas R, Lévesque C, Thompson Legault J, Rivard ME, Villeneuve L, Laprise C, Rioux JD. Human induced pluripotent stem cells (hiPSCs) derived cells reflect tissue specificity found in patients with Leigh syndrome French Canadian variant (LSFC). Front Genet 2024; 15:1375467. [PMID: 38706791 PMCID: PMC11066297 DOI: 10.3389/fgene.2024.1375467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 04/02/2024] [Indexed: 05/07/2024] Open
Abstract
Leigh syndrome French Canadian type (LSFC) is a recessive neurodegenerative disease characterized by tissue-specific deficiency in cytochrome c oxidase (COX), the fourth complex in the oxidative phosphorylation system. LSFC is caused by mutations in the leucine rich pentatricopeptide repeat containing gene (LRPPRC). Most LSFC patients in Quebec are homozygous for an A354V substitution that causes a decrease in the expression of the LRPPRC protein. While LRPPRC is ubiquitously expressed and is involved in multiple cellular functions, tissue-specific expression of LRPPRC and COX activity is correlated with clinical features. In this proof-of-principle study, we developed human induced pluripotent stem cell (hiPSC)-based models from fibroblasts taken from a patient with LSFC, homozygous for the LRPPRC*354V allele, and from a control, homozygous for the LRPPRC*A354 allele. Specifically, for both of these fibroblast lines we generated hiPSC, hiPSC-derived cardiomyocytes (hiPSC-CMs) and hepatocyte-like cell (hiPSC-HLCs) lines, as well as the three germ layers. We observed that LRPPRC protein expression is reduced in all cell lines/layers derived from LSFC patient compared to control cells, with a reduction ranging from ∼70% in hiPSC-CMs to undetectable levels in hiPSC-HLC, reflecting tissue heterogeneity observed in patient tissues. We next performed exploratory analyses of these cell lines and observed that COX protein expression was reduced in all cell lines derived from LSFC patient compared to control cells. We also observed that mutant LRPPRC was associated with altered expression of key markers of endoplasmic reticulum stress response in hiPSC-HLCs but not in other cell types that were tested. While this demonstrates feasibility of the approach to experimentally study genotype-based differences that have tissue-specific impacts, this study will need to be extended to a larger number of patients and controls to not only validate the current observations but also to delve more deeply in the pathogenic mechanisms of LSFC.
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Affiliation(s)
| | | | | | | | | | | | - John D. Rioux
- Montreal Heart Institute, Montreal, QC, Canada
- Université de Montréal, Montreal, QC, Canada
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Caron-Godon CA, Collington E, Wolf JL, Coletta G, Glerum DM. More than Just Bread and Wine: Using Yeast to Understand Inherited Cytochrome Oxidase Deficiencies in Humans. Int J Mol Sci 2024; 25:3814. [PMID: 38612624 PMCID: PMC11011759 DOI: 10.3390/ijms25073814] [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: 03/06/2024] [Revised: 03/26/2024] [Accepted: 03/28/2024] [Indexed: 04/14/2024] Open
Abstract
Inherited defects in cytochrome c oxidase (COX) are associated with a substantial subset of diseases adversely affecting the structure and function of the mitochondrial respiratory chain. This multi-subunit enzyme consists of 14 subunits and numerous cofactors, and it requires the function of some 30 proteins to assemble. COX assembly was first shown to be the primary defect in the majority of COX deficiencies 36 years ago. Over the last three decades, most COX assembly genes have been identified in the yeast Saccharomyces cerevisiae, and studies in yeast have proven instrumental in testing the impact of mutations identified in patients with a specific COX deficiency. The advent of accessible genome-wide sequencing capabilities has led to more patient mutations being identified, with the subsequent identification of several new COX assembly factors. However, the lack of genotype-phenotype correlations and the large number of genes involved in generating a functional COX mean that functional studies must be undertaken to assign a genetic variant as being causal. In this review, we provide a brief overview of the use of yeast as a model system and briefly compare the COX assembly process in yeast and humans. We focus primarily on the studies in yeast that have allowed us to both identify new COX assembly factors and to demonstrate the pathogenicity of a subset of the mutations that have been identified in patients with inherited defects in COX. We conclude with an overview of the areas in which studies in yeast are likely to continue to contribute to progress in understanding disease arising from inherited COX deficiencies.
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Affiliation(s)
- Chenelle A. Caron-Godon
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada; (C.A.C.-G.); (E.C.); (J.L.W.); (G.C.)
| | - Emma Collington
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada; (C.A.C.-G.); (E.C.); (J.L.W.); (G.C.)
| | - Jessica L. Wolf
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada; (C.A.C.-G.); (E.C.); (J.L.W.); (G.C.)
| | - Genna Coletta
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada; (C.A.C.-G.); (E.C.); (J.L.W.); (G.C.)
| | - D. Moira Glerum
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada; (C.A.C.-G.); (E.C.); (J.L.W.); (G.C.)
- Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
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3
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Coordination of metal center biogenesis in human cytochrome c oxidase. Nat Commun 2022; 13:3615. [PMID: 35750769 PMCID: PMC9232578 DOI: 10.1038/s41467-022-31413-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 06/16/2022] [Indexed: 01/12/2023] Open
Abstract
Mitochondrial cytochrome c oxidase (CcO) or respiratory chain complex IV is a heme aa3-copper oxygen reductase containing metal centers essential for holo-complex biogenesis and enzymatic function that are assembled by subunit-specific metallochaperones. The enzyme has two copper sites located in the catalytic core subunits. The COX1 subunit harbors the CuB site that tightly associates with heme a3 while the COX2 subunit contains the binuclear CuA site. Here, we report that in human cells the CcO copper chaperones form macromolecular assemblies and cooperate with several twin CX9C proteins to control heme a biosynthesis and coordinate copper transfer sequentially to the CuA and CuB sites. These data on CcO illustrate a mechanism that regulates the biogenesis of macromolecular enzymatic assemblies with several catalytic metal redox centers and prevents the accumulation of cytotoxic reactive assembly intermediates.
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Inak G, Rybak-Wolf A, Lisowski P, Pentimalli TM, Jüttner R, Glažar P, Uppal K, Bottani E, Brunetti D, Secker C, Zink A, Meierhofer D, Henke MT, Dey M, Ciptasari U, Mlody B, Hahn T, Berruezo-Llacuna M, Karaiskos N, Di Virgilio M, Mayr JA, Wortmann SB, Priller J, Gotthardt M, Jones DP, Mayatepek E, Stenzel W, Diecke S, Kühn R, Wanker EE, Rajewsky N, Schuelke M, Prigione A. Defective metabolic programming impairs early neuronal morphogenesis in neural cultures and an organoid model of Leigh syndrome. Nat Commun 2021; 12:1929. [PMID: 33771987 PMCID: PMC7997884 DOI: 10.1038/s41467-021-22117-z] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 03/01/2021] [Indexed: 12/12/2022] Open
Abstract
Leigh syndrome (LS) is a severe manifestation of mitochondrial disease in children and is currently incurable. The lack of effective models hampers our understanding of the mechanisms underlying the neuronal pathology of LS. Using patient-derived induced pluripotent stem cells and CRISPR/Cas9 engineering, we developed a human model of LS caused by mutations in the complex IV assembly gene SURF1. Single-cell RNA-sequencing and multi-omics analysis revealed compromised neuronal morphogenesis in mutant neural cultures and brain organoids. The defects emerged at the level of neural progenitor cells (NPCs), which retained a glycolytic proliferative state that failed to instruct neuronal morphogenesis. LS NPCs carrying mutations in the complex I gene NDUFS4 recapitulated morphogenesis defects. SURF1 gene augmentation and PGC1A induction via bezafibrate treatment supported the metabolic programming of LS NPCs, leading to restored neuronal morphogenesis. Our findings provide mechanistic insights and suggest potential interventional strategies for a rare mitochondrial disease.
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Affiliation(s)
- Gizem Inak
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Duesseldorf University Hospital, Medical Faculty, Heinrich Heine University, Duesseldorf, Germany
| | - Agnieszka Rybak-Wolf
- Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine (MDC), Hannoversche Str 28, 10115, Berlin, Germany
| | - Pawel Lisowski
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Duesseldorf University Hospital, Medical Faculty, Heinrich Heine University, Duesseldorf, Germany
- Institute of Genetics and Animal Biotechnology, Polish Academy of Sciences, Jastrzebiec, n/Warsaw, Magdalenka, Poland
| | - Tancredi M Pentimalli
- Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine (MDC), Hannoversche Str 28, 10115, Berlin, Germany
| | - René Jüttner
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Petar Glažar
- Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine (MDC), Hannoversche Str 28, 10115, Berlin, Germany
| | | | - Emanuela Bottani
- Department of Diagnostics and Public Health, University of Verona, Verona, Italy
| | - Dario Brunetti
- Mitochondrial Medicine Laboratory, Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
- Unit of Medical Genetics and Neurogenetics Fondazione IRCCS Istituto Neurologico "Carlo Besta", Milan, Italy
| | - Christopher Secker
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
- Charité - Universitätsmedizin Berlin, Department of Neurology, Berlin, Germany
| | - Annika Zink
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Duesseldorf University Hospital, Medical Faculty, Heinrich Heine University, Duesseldorf, Germany
- Charité - Universitätsmedizin Berlin, Department of Neuropsychiatry, Berlin, Germany
| | | | - Marie-Thérèse Henke
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
- Charité - Universitätsmedizin Berlin, Department of Neuropediatrics, Berlin, Germany
| | - Monishita Dey
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Ummi Ciptasari
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Barbara Mlody
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Tobias Hahn
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | | | - Nikos Karaiskos
- Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine (MDC), Hannoversche Str 28, 10115, Berlin, Germany
| | | | - Johannes A Mayr
- University Children's Hospital, Paracelsus Medical University (PMU), Salzburg, Austria
| | - Saskia B Wortmann
- University Children's Hospital, Paracelsus Medical University (PMU), Salzburg, Austria
- Radboud Center for Mitochondrial Medicine, Department of Pediatrics, Amalia Children's Hospital, Radboudumc, Nijmegen, The Netherlands
| | - Josef Priller
- Charité - Universitätsmedizin Berlin, Department of Neuropsychiatry, Berlin, Germany
- University of Edinburgh and UK DRI, Edinburgh, UK
- Department of Psychiatry and Psychotherapy, Klinikum rechts der Isar, Technical University Munich, Munich, Germany
| | | | | | - Ertan Mayatepek
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Duesseldorf University Hospital, Medical Faculty, Heinrich Heine University, Duesseldorf, Germany
| | - Werner Stenzel
- Charité - Universitätsmedizin, Department of Neuropathology, Berlin, Germany
| | - Sebastian Diecke
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
- Berlin Institute of Health (BIH), Berlin, Germany
| | - Ralf Kühn
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Erich E Wanker
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Nikolaus Rajewsky
- Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine (MDC), Hannoversche Str 28, 10115, Berlin, Germany.
| | - Markus Schuelke
- Charité - Universitätsmedizin Berlin, Department of Neuropediatrics, Berlin, Germany.
- NeuroCure Clinical Research Center, Berlin, Germany.
| | - Alessandro Prigione
- Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany.
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Duesseldorf University Hospital, Medical Faculty, Heinrich Heine University, Duesseldorf, Germany.
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Kaustio M, Nayebzadeh N, Hinttala R, Tapiainen T, Åström P, Mamia K, Pernaa N, Lehtonen J, Glumoff V, Rahikkala E, Honkila M, Olsén P, Hassinen A, Polso M, Al Sukaiti N, Al Shekaili J, Al Kindi M, Al Hashmi N, Almusa H, Bulanova D, Haapaniemi E, Chen P, Suo-Palosaari M, Vieira P, Tuominen H, Kokkonen H, Al Macki N, Al Habsi H, Löppönen T, Rantala H, Pietiäinen V, Zhang SY, Renko M, Hautala T, Al Farsi T, Uusimaa J, Saarela J. Loss of DIAPH1 causes SCBMS, combined immunodeficiency, and mitochondrial dysfunction. J Allergy Clin Immunol 2021; 148:599-611. [PMID: 33662367 DOI: 10.1016/j.jaci.2020.12.656] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 11/15/2020] [Accepted: 12/08/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND Homozygous loss of DIAPH1 results in seizures, cortical blindness, and microcephaly syndrome (SCBMS). We studied 5 Finnish and 2 Omani patients with loss of DIAPH1 presenting with SCBMS, mitochondrial dysfunction, and immunodeficiency. OBJECTIVE We sought to further characterize phenotypes and disease mechanisms associated with loss of DIAPH1. METHODS Exome sequencing, genotyping and haplotype analysis, B- and T-cell phenotyping, in vitro lymphocyte stimulation assays, analyses of mitochondrial function, immunofluorescence staining for cytoskeletal proteins and mitochondria, and CRISPR-Cas9 DIAPH1 knockout in heathy donor PBMCs were used. RESULTS Genetic analyses found all Finnish patients homozygous for a rare DIAPH1 splice-variant (NM_005219:c.684+1G>A) enriched in the Finnish population, and Omani patients homozygous for a previously described pathogenic DIAPH1 frameshift-variant (NM_005219:c.2769delT;p.F923fs). In addition to microcephaly, epilepsy, and cortical blindness characteristic to SCBMS, the patients presented with infection susceptibility due to defective lymphocyte maturation and 3 patients developed B-cell lymphoma. Patients' immunophenotype was characterized by poor lymphocyte activation and proliferation, defective B-cell maturation, and lack of naive T cells. CRISPR-Cas9 knockout of DIAPH1 in PBMCs from healthy donors replicated the T-cell activation defect. Patient-derived peripheral blood T cells exhibited impaired adhesion and inefficient microtubule-organizing center repositioning to the immunologic synapse. The clinical symptoms and laboratory tests also suggested mitochondrial dysfunction. Experiments with immortalized, patient-derived fibroblasts indicated that DIAPH1 affects the amount of complex IV of the mitochondrial respiratory chain. CONCLUSIONS Our data demonstrate that individuals with SCBMS can have combined immune deficiency and implicate defective cytoskeletal organization and mitochondrial dysfunction in SCBMS pathogenesis.
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Affiliation(s)
- Meri Kaustio
- Institute for Molecular Medicine Finland (FIMM), HiLIFE, University of Helsinki, Helsinki, Finland
| | - Naemeh Nayebzadeh
- PEDEGO Research Unit, University of Oulu, Oulu, Finland; Medical Research Center Oulu, University of Oulu, Oulu, Finland; Biocenter Oulu, Oulu, Finland
| | - Reetta Hinttala
- PEDEGO Research Unit, University of Oulu, Oulu, Finland; Medical Research Center Oulu, University of Oulu, Oulu, Finland; Biocenter Oulu, Oulu, Finland
| | - Terhi Tapiainen
- PEDEGO Research Unit, University of Oulu, Oulu, Finland; Medical Research Center Oulu, University of Oulu, Oulu, Finland; Biocenter Oulu, Oulu, Finland; Department of Pediatrics and Adolescent Medicine, Oulu University Hospital, Oulu, Finland
| | - Pirjo Åström
- Research Unit of Biomedicine, University of Oulu, Oulu, Finland
| | - Katariina Mamia
- Centre for Molecular Medicine Norway (NCMM), University of Oslo, Oslo, Norway
| | - Nora Pernaa
- Research Unit of Biomedicine, University of Oulu, Oulu, Finland
| | - Johanna Lehtonen
- Institute for Molecular Medicine Finland (FIMM), HiLIFE, University of Helsinki, Helsinki, Finland; Centre for Molecular Medicine Norway (NCMM), University of Oslo, Oslo, Norway; Folkhälsan Research Center, Helsinki, Finland
| | - Virpi Glumoff
- Research Unit of Biomedicine, University of Oulu, Oulu, Finland
| | - Elisa Rahikkala
- PEDEGO Research Unit, University of Oulu, Oulu, Finland; Medical Research Center Oulu, University of Oulu, Oulu, Finland; Department of Clinical Genetics, Oulu University Hospital, Oulu, Finland
| | - Minna Honkila
- PEDEGO Research Unit, University of Oulu, Oulu, Finland; Medical Research Center Oulu, University of Oulu, Oulu, Finland; Department of Pediatrics and Adolescent Medicine, Oulu University Hospital, Oulu, Finland
| | - Päivi Olsén
- PEDEGO Research Unit, University of Oulu, Oulu, Finland; Medical Research Center Oulu, University of Oulu, Oulu, Finland; Department of Pediatrics and Adolescent Medicine, Oulu University Hospital, Oulu, Finland
| | - Antti Hassinen
- Institute for Molecular Medicine Finland (FIMM), HiLIFE, University of Helsinki, Helsinki, Finland
| | - Minttu Polso
- Institute for Molecular Medicine Finland (FIMM), HiLIFE, University of Helsinki, Helsinki, Finland
| | - Nashat Al Sukaiti
- Department of Pediatric Allergy and Clinical Immunology, The Royal Hospital, Muscat, Oman
| | - Jalila Al Shekaili
- Department of Microbiology and Immunology, Sultan Qaboos University Hospital, Muscat, Oman
| | - Mahmood Al Kindi
- Department of Microbiology and Immunology, Sultan Qaboos University Hospital, Muscat, Oman
| | - Nadia Al Hashmi
- Department of Clinical and Biochemical Genetics, The Royal Hospital, Muscat, Oman
| | - Henrikki Almusa
- Institute for Molecular Medicine Finland (FIMM), HiLIFE, University of Helsinki, Helsinki, Finland
| | - Daria Bulanova
- Institute for Molecular Medicine Finland (FIMM), HiLIFE, University of Helsinki, Helsinki, Finland; Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Emma Haapaniemi
- Centre for Molecular Medicine Norway (NCMM), University of Oslo, Oslo, Norway; Department of Pediatric Research, Oslo University Hospital, Oslo, Norway; Research Programs Unit, Molecular Neurology and Biomedicum Stem Cell Centre, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Pu Chen
- Institute for Molecular Medicine Finland (FIMM), HiLIFE, University of Helsinki, Helsinki, Finland
| | - Maria Suo-Palosaari
- Medical Research Center Oulu, University of Oulu, Oulu, Finland; Department of Diagnostic Radiology, Oulu University Hospital and University of Oulu, Oulu, Finland; Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Päivi Vieira
- PEDEGO Research Unit, University of Oulu, Oulu, Finland; Medical Research Center Oulu, University of Oulu, Oulu, Finland; Department of Pediatrics and Adolescent Medicine, Oulu University Hospital, Oulu, Finland
| | - Hannu Tuominen
- Department of Pathology, Oulu University Hospital, Oulu, Finland
| | - Hannaleena Kokkonen
- Medical Research Center Oulu, University of Oulu, Oulu, Finland; Department of Clinical Genetics, Northern Finland Laboratory Centre, Oulu University Hospital, Oulu, Finland
| | - Nabil Al Macki
- Department of Pediatric Neurology, The Royal Hospital, Muscat, Oman
| | - Huda Al Habsi
- Department of General Pediatrics, The Royal Hospital, Muscat, Oman
| | - Tuija Löppönen
- Department of Pediatrics, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland
| | | | - Vilja Pietiäinen
- Institute for Molecular Medicine Finland (FIMM), HiLIFE, University of Helsinki, Helsinki, Finland
| | - Shen-Ying Zhang
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY; Paris Descartes University, Imagine Institute, Paris, France; Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM UMR 1163, Necker Hospital for Sick Children, Paris, France
| | - Marjo Renko
- PEDEGO Research Unit, University of Oulu, Oulu, Finland; Department of Pediatrics, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland
| | - Timo Hautala
- Research Unit of Biomedicine, University of Oulu, Oulu, Finland; Department of Internal Medicine, Oulu University Hospital, Oulu, Finland
| | - Tariq Al Farsi
- Department of Pediatric Allergy and Clinical Immunology, The Royal Hospital, Muscat, Oman
| | - Johanna Uusimaa
- PEDEGO Research Unit, University of Oulu, Oulu, Finland; Medical Research Center Oulu, University of Oulu, Oulu, Finland; Department of Pediatrics and Adolescent Medicine, Oulu University Hospital, Oulu, Finland
| | - Janna Saarela
- Institute for Molecular Medicine Finland (FIMM), HiLIFE, University of Helsinki, Helsinki, Finland; Centre for Molecular Medicine Norway (NCMM), University of Oslo, Oslo, Norway; Department of Medical Genetics, Oslo University Hospital, Oslo, Norway; Department of Clinical Genetics, Helsinki University Hospital, Helsinki, Finland.
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Gras DE, Mansilla N, Rodríguez C, Welchen E, Gonzalez DH. Arabidopsis thaliana SURFEIT1-like genes link mitochondrial function to early plant development and hormonal growth responses. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:690-704. [PMID: 32248588 DOI: 10.1111/tpj.14762] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 03/02/2020] [Accepted: 03/23/2020] [Indexed: 06/11/2023]
Abstract
Mutations in SURFEIT1 (SURF1) genes affect cytochrome c oxidase (COX) levels in different prokaryotic and eukaryotic organisms. In this work, we report that Arabidopsis thaliana has two genes that potentially encode SURF1 proteins, as a result of a duplication that took place in Brassicaceae. Both genes encode mitochondrial proteins and mutation in AtSURF1a causes embryonic lethality. Mutation in AtSURF1b, instead, causes defects in hypocotyl elongation under growth-stimulating conditions, such as low light intensity, increased ambient temperature and incubation with glucose. Mutants in AtSURF1b show reduced expression of the auxin reporter DR5:GUS and increased levels of the gibberellin reporter GFP-RGA, suggesting that auxin and gibberellin homeostasis are affected. In agreement, growth defects caused by AtSURF1b mutation can be overcome by treatment with indole-3-acetic acid and gibberellin A3 , and also by increasing expression of the auxin biosynthesis gene YUC8 or the transcription factor PIF4, which shows lower abundance in AtSURF1b-deficient plants. Mutants in AtSURF1b display lower COX levels, higher alternative oxidase and superoxide levels, and increased expression of genes that respond to mitochondrial dysfunction. Decreased hypocotyl growth and DR5:GUS expression can be reversed by treatment with reduced glutathione, suggesting that redox changes, probably related to mitochondrial dysfunction, are responsible for the effect of AtSURF1b deficiency on hormone responses. The results indicate that changes in AtSURF1b affect mitochondrial function and the production of reactive oxygen species, which, in turn, impinges on a growth regulatory circuit that involves auxin, gibberellins and the transcription factor PIF4.
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Affiliation(s)
- Diana E Gras
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, 3000, Santa Fe, Argentina
| | - Natanael Mansilla
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, 3000, Santa Fe, Argentina
| | - Carina Rodríguez
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, 3000, Santa Fe, Argentina
| | - Elina Welchen
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, 3000, Santa Fe, Argentina
| | - Daniel H Gonzalez
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, 3000, Santa Fe, Argentina
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7
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Mani S, Chandak GR, Singh KK, Singh R, Rao SN. Novel p.P298L SURF1 mutation in thiamine deficient Leigh syndrome patients compromises cytochrome c oxidase activity. Mitochondrion 2020; 53:91-98. [PMID: 32380162 DOI: 10.1016/j.mito.2020.04.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 04/20/2020] [Accepted: 04/29/2020] [Indexed: 01/15/2023]
Abstract
SURF1 is a nuclear gene and encodes for an important assembly factor for cytochrome c oxidase enzyme. A number of mutations in SURF1 gene render cytochrome c oxidase deficiency, a major causative factor for Leigh syndrome. We screened all the 9 exons and exon-intron boundaries of SURF1 gene in 165 Indian Leigh syndrome patients who were thiamine responsive too. Consequently, we identified several novel and reported nucleotide variations in this gene. The nucleotide changes were analysed by using different in-silico tools for predicting their pathogenicity. Based upon the predictions, we further validated the analyzed functional significance of p.N249D and p.P298L mutations in SURF1 protein using COS-7 cells. Though, both the mutations did not affect the localization of SURF1protein into the mitochondria. But, interestingly the novel mutation p.P298L was reported to significantly compromise the COX activity in these cells.
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Affiliation(s)
- Shalini Mani
- Department of Biotechnology, Centre for Emerging Disease, Jaypee Institute of Information Technology, Noida, India; CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, India.
| | - G R Chandak
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, India
| | - Keshav K Singh
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Rajender Singh
- Division of Endocrinology, Central Drug Research Institute, Lucknow, India
| | - S Narasimha Rao
- Government Institute of Child Health, Niloufer Hospital for Women and Children, Red Hills, Hyderabad, India
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8
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Paakkola T, Salokas K, Miinalainen I, Lehtonen S, Manninen A, Kaakinen M, Ruddock LW, Varjosalo M, Kaarteenaho R, Uusimaa J, Hinttala R. Biallelic mutations in human NHLRC2 enhance myofibroblast differentiation in FINCA disease. Hum Mol Genet 2019; 27:4288-4302. [PMID: 30239752 DOI: 10.1093/hmg/ddy298] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 08/14/2018] [Indexed: 01/04/2023] Open
Abstract
The development of tissue fibrosis is complex and at the present time, not fully understood. Fibrosis, neurodegeneration and cerebral angiomatosis (FINCA disease) have been described in patients with mutations in NHL repeat-containing protein 2 (NHLRC2). However, the molecular functions of NHLRC2 are uncharacterized. Herein, we identified putative interacting partners for NHLRC2 using proximity-labeling mass spectrometry. We also investigated the function of NHLRC2 using immortalized cells cultured from skin biopsies of FINCA patients and normal fibroblasts with NHLRC2 knock-down and NHLRC2 overexpressing gene modifications. Transmission electron microscopy analysis of immortalized cell cultures from three FINCA patients demonstrated multilamellar bodies and distinctly organized vimentin filaments. Additionally, two of three cultures derived from patient skin biopsies contained cells that exhibited features characteristic of myofibroblasts. Altogether, the data presented in this study show for the first time that NHLRC2 is involved in cellular organization through regulation of the cytoskeleton and vesicle transport. We conclude that compound heterozygous p.Asp148Tyr and p.Arg201GlyfsTer6 mutations in NHLRC2 lead to severe tissue fibrosis in humans by enhancing the differentiation of fibroblasts to myofibroblasts.
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Affiliation(s)
- Teija Paakkola
- PEDEGO Research Unit, University of Oulu, Oulu, Finland.,Biocenter Oulu, University of Oulu, Oulu, Finland.,Oulu University Hospital, Oulu, Finland.,Medical Research Center Oulu, University of Oulu, Oulu, Finland
| | - Kari Salokas
- Institute of Biotechnology, University of Helsinki, Finland, Helsinki, Finland.,Helsinki Institute of Life Science (HiLIFE), University of Helsinki, Finland, Helsinki, Finland
| | | | | | - Aki Manninen
- Biocenter Oulu, University of Oulu, Oulu, Finland.,Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | | | - Lloyd W Ruddock
- Biocenter Oulu, University of Oulu, Oulu, Finland.,Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Markku Varjosalo
- Institute of Biotechnology, University of Helsinki, Finland, Helsinki, Finland.,Helsinki Institute of Life Science (HiLIFE), University of Helsinki, Finland, Helsinki, Finland
| | - Riitta Kaarteenaho
- Research Unit of Internal Medicine, University of Oulu, Oulu, Finland.,Unit of Internal Medicine and Respiratory Medicine, Oulu University Hospital, OYS, Oulu, Finland.,Medical Research Center Oulu, University of Oulu, Oulu, Finland
| | - Johanna Uusimaa
- PEDEGO Research Unit, University of Oulu, Oulu, Finland.,Biocenter Oulu, University of Oulu, Oulu, Finland.,Oulu University Hospital, Oulu, Finland.,Department of Children and Adolescents, Oulu University Hospital, Oulu, Finland.,Medical Research Center Oulu, University of Oulu, Oulu, Finland
| | - Reetta Hinttala
- PEDEGO Research Unit, University of Oulu, Oulu, Finland.,Biocenter Oulu, University of Oulu, Oulu, Finland.,Oulu University Hospital, Oulu, Finland.,Medical Research Center Oulu, University of Oulu, Oulu, Finland
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9
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Mukaneza Y, Cohen A, Rivard MÈ, Tardif J, Deschênes S, Ruiz M, Laprise C, Des Rosiers C, Coderre L. mTORC1 is required for expression of LRPPRC and cytochrome- c oxidase but not HIF-1α in Leigh syndrome French Canadian type patient fibroblasts. Am J Physiol Cell Physiol 2019; 317:C58-C67. [PMID: 30995105 DOI: 10.1152/ajpcell.00160.2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Leigh syndrome French Canadian type (LSFC) is a mitochondrial disease caused by mutations in the leucine-rich pentatricopeptide repeat-containing (LRPPRC) gene leading to a reduction of cytochrome-c oxidase (COX) expression reaching 50% in skin fibroblasts. We have shown that under basal conditions, LSFC and control cells display similar ATP levels. We hypothesized that this occurs through upregulation of mechanistic target of rapamycin (mTOR)-mediated metabolic reprogramming. Our results showed that compared with controls, LSFC cells exhibited an upregulation of the mTOR complex 1 (mTORC1)/p70 ribosomal S6 kinase pathway and higher levels of hypoxia-inducible factor 1α (HIF-1α) and its downstream target pyruvate dehydrogenase kinase 1 (PDHK1), a regulator of mitochondrial pyruvate dehydrogenase 1 (PDH1). Consistent with these signaling alterations, LSFC cells displayed a 40-61% increase in [U-13C6]glucose contribution to pyruvate, lactate, and alanine formation, as well as higher levels of the phosphorylated and inactive form of PDH1-α. Interestingly, inhibition of mTOR with rapamycin did not alter HIF-1α or PDHK1 protein levels in LSFC fibroblasts. However, this treatment increased PDH1-α phosphorylation in control and LSFC cells and reduced ATP levels in control cells. Rapamycin also decreased LRPPRC expression by 41 and 11% in LSFC and control cells, respectively, and selectively reduced COX subunit IV expression in LSFC fibroblasts. Taken together, our data demonstrate the importance of mTORC1, independent of the HIF-1α/PDHK1 axis, in maintaining LRPPRC and COX expression in LSFC cells.
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Affiliation(s)
- Yvette Mukaneza
- Department of Nutrition, Université de Montréal , Montreal, Quebec , Canada.,Research Centre, Montreal Heart Institute , Montreal, Quebec , Canada
| | - Aaron Cohen
- Research Centre, Montreal Heart Institute , Montreal, Quebec , Canada
| | - Marie-Ève Rivard
- Research Centre, Montreal Heart Institute , Montreal, Quebec , Canada
| | - Jessica Tardif
- Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi, Quebec , Canada
| | - Sonia Deschênes
- Research Centre, Montreal Heart Institute , Montreal, Quebec , Canada
| | - Matthieu Ruiz
- Department of Medicine, Université de Montréal , Montreal, Quebec , Canada.,Research Centre, Montreal Heart Institute , Montreal, Quebec , Canada
| | | | - Catherine Laprise
- Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi, Quebec , Canada
| | - Christine Des Rosiers
- Department of Nutrition, Université de Montréal , Montreal, Quebec , Canada.,Research Centre, Montreal Heart Institute , Montreal, Quebec , Canada
| | - Lise Coderre
- Department of Medicine, Université de Montréal , Montreal, Quebec , Canada.,Research Centre, Montreal Heart Institute , Montreal, Quebec , Canada
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10
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SURF1 mutations in Chinese patients with Leigh syndrome: Novel mutations, mutation spectrum, and the functional consequences. Gene 2018; 674:15-24. [DOI: 10.1016/j.gene.2018.06.058] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 06/07/2018] [Accepted: 06/18/2018] [Indexed: 01/02/2023]
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11
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Quadalti C, Brunetti D, Lagutina I, Duchi R, Perota A, Lazzari G, Cerutti R, Di Meo I, Johnson M, Bottani E, Crociara P, Corona C, Grifoni S, Tiranti V, Fernandez-Vizarra E, Robinson AJ, Viscomi C, Casalone C, Zeviani M, Galli C. SURF1 knockout cloned pigs: Early onset of a severe lethal phenotype. Biochim Biophys Acta Mol Basis Dis 2018; 1864:2131-2142. [PMID: 29601977 PMCID: PMC6018622 DOI: 10.1016/j.bbadis.2018.03.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 02/28/2018] [Accepted: 03/22/2018] [Indexed: 12/15/2022]
Abstract
Leigh syndrome (LS) associated with cytochrome c oxidase (COX) deficiency is an early onset, fatal mitochondrial encephalopathy, leading to multiple neurological failure and eventually death, usually in the first decade of life. Mutations in SURF1, a nuclear gene encoding a mitochondrial protein involved in COX assembly, are among the most common causes of LS. LSSURF1 patients display severe, isolated COX deficiency in all tissues, including cultured fibroblasts and skeletal muscle. Recombinant, constitutive SURF1-/- mice show diffuse COX deficiency, but fail to recapitulate the severity of the human clinical phenotype. Pigs are an attractive alternative model for human diseases, because of their size, as well as metabolic, physiological and genetic similarity to humans. Here, we determined the complete sequence of the swine SURF1 gene, disrupted it in pig primary fibroblast cell lines using both TALENs and CRISPR/Cas9 genome editing systems, before finally generating SURF1-/- and SURF1-/+ pigs by Somatic Cell Nuclear Transfer (SCNT). SURF1-/- pigs were characterized by failure to thrive, muscle weakness and highly reduced life span with elevated perinatal mortality, compared to heterozygous SURF1-/+ and wild type littermates. Surprisingly, no obvious COX deficiency was detected in SURF1-/- tissues, although histochemical analysis revealed the presence of COX deficiency in jejunum villi and total mRNA sequencing (RNAseq) showed that several COX subunit-encoding genes were significantly down-regulated in SURF1-/- skeletal muscles. In addition, neuropathological findings, indicated a delay in central nervous system development of newborn SURF1-/- piglets. Our results suggest a broader role of sSURF1 in mitochondrial bioenergetics.
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Affiliation(s)
- C Quadalti
- Avantea, Laboratory of Reproductive Technologies, Via Porcellasco 7/f, Cremona 26100, Italy; Dept. of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, 40064 Ozzano dell'Emilia, BO, Italy
| | - D Brunetti
- University of Cambridge/MRC Mitochondrial Biology Unit, Wellcome Trust/MRC Building, Hills Rd, Cambridge CB20XY, UK
| | - I Lagutina
- Avantea, Laboratory of Reproductive Technologies, Via Porcellasco 7/f, Cremona 26100, Italy
| | - R Duchi
- Avantea, Laboratory of Reproductive Technologies, Via Porcellasco 7/f, Cremona 26100, Italy
| | - A Perota
- Avantea, Laboratory of Reproductive Technologies, Via Porcellasco 7/f, Cremona 26100, Italy
| | - G Lazzari
- Avantea, Laboratory of Reproductive Technologies, Via Porcellasco 7/f, Cremona 26100, Italy; Fondazione Avantea, Cremona, Italy
| | - R Cerutti
- University of Cambridge/MRC Mitochondrial Biology Unit, Wellcome Trust/MRC Building, Hills Rd, Cambridge CB20XY, UK
| | - I Di Meo
- Neurologic Institute Carlo Besta, Via G. Celoria 11, 20133 Milan, Italy
| | - M Johnson
- University of Cambridge/MRC Mitochondrial Biology Unit, Wellcome Trust/MRC Building, Hills Rd, Cambridge CB20XY, UK
| | - E Bottani
- University of Cambridge/MRC Mitochondrial Biology Unit, Wellcome Trust/MRC Building, Hills Rd, Cambridge CB20XY, UK
| | - P Crociara
- Istituto Zooprofilattico Sperimentale del Piemonte Liguria e Valle d'Aosta, Via Bologna 148, Torino 10154, Italy
| | - C Corona
- Istituto Zooprofilattico Sperimentale del Piemonte Liguria e Valle d'Aosta, Via Bologna 148, Torino 10154, Italy
| | - S Grifoni
- Istituto Zooprofilattico Sperimentale del Piemonte Liguria e Valle d'Aosta, Via Bologna 148, Torino 10154, Italy
| | - V Tiranti
- Neurologic Institute Carlo Besta, Via G. Celoria 11, 20133 Milan, Italy
| | - E Fernandez-Vizarra
- University of Cambridge/MRC Mitochondrial Biology Unit, Wellcome Trust/MRC Building, Hills Rd, Cambridge CB20XY, UK
| | - A J Robinson
- University of Cambridge/MRC Mitochondrial Biology Unit, Wellcome Trust/MRC Building, Hills Rd, Cambridge CB20XY, UK
| | - C Viscomi
- University of Cambridge/MRC Mitochondrial Biology Unit, Wellcome Trust/MRC Building, Hills Rd, Cambridge CB20XY, UK
| | - C Casalone
- Istituto Zooprofilattico Sperimentale del Piemonte Liguria e Valle d'Aosta, Via Bologna 148, Torino 10154, Italy
| | - M Zeviani
- University of Cambridge/MRC Mitochondrial Biology Unit, Wellcome Trust/MRC Building, Hills Rd, Cambridge CB20XY, UK.
| | - C Galli
- Avantea, Laboratory of Reproductive Technologies, Via Porcellasco 7/f, Cremona 26100, Italy; Dept. of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, 40064 Ozzano dell'Emilia, BO, Italy.
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12
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Quintana AM, Yu HC, Brebner A, Pupavac M, Geiger EA, Watson A, Castro VL, Cheung W, Chen SH, Watkins D, Pastinen T, Skovby F, Appel B, Rosenblatt DS, Shaikh TH. Mutations in THAP11 cause an inborn error of cobalamin metabolism and developmental abnormalities. Hum Mol Genet 2018; 26:2838-2849. [PMID: 28449119 DOI: 10.1093/hmg/ddx157] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 04/20/2017] [Indexed: 11/14/2022] Open
Abstract
CblX (MIM309541) is an X-linked recessive disorder characterized by defects in cobalamin (vitamin B12) metabolism and other developmental defects. Mutations in HCFC1, a transcriptional co-regulator which interacts with multiple transcription factors, have been associated with cblX. HCFC1 regulates cobalamin metabolism via the regulation of MMACHC expression through its interaction with THAP11, a THAP domain-containing transcription factor. The HCFC1/THAP11 complex potentially regulates genes involved in diverse cellular functions including cell cycle, proliferation, and transcription. Thus, it is likely that mutation of THAP11 also results in biochemical and other phenotypes similar to those observed in patients with cblX. We report a patient who presented with clinical and biochemical phenotypic features that overlap cblX, but who does not have any mutations in either MMACHC or HCFC1. We sequenced THAP11 by Sanger sequencing and discovered a potentially pathogenic, homozygous variant, c.240C > G (p.Phe80Leu). Functional analysis in the developing zebrafish embryo demonstrated that both THAP11 and HCFC1 regulate the proliferation and differentiation of neural precursors, suggesting important roles in normal brain development. The loss of THAP11 in zebrafish embryos results in craniofacial abnormalities including the complete loss of Meckel's cartilage, the ceratohyal, and all of the ceratobranchial cartilages. These data are consistent with our previous work that demonstrated a role for HCFC1 in vertebrate craniofacial development. High throughput RNA-sequencing analysis reveals several overlapping gene targets of HCFC1 and THAP11. Thus, both HCFC1 and THAP11 play important roles in the regulation of cobalamin metabolism as well as other pathways involved in early vertebrate development.
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Affiliation(s)
- Anita M Quintana
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, USA
| | - Hung-Chun Yu
- Section of Genetics, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Alison Brebner
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada
| | - Mihaela Pupavac
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada
| | - Elizabeth A Geiger
- Section of Genetics, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Abigail Watson
- Section of Genetics, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Victoria L Castro
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, USA
| | - Warren Cheung
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada
| | - Shu-Huang Chen
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada
| | - David Watkins
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada
| | - Tomi Pastinen
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada
| | - Flemming Skovby
- Department of Clinical Genetics, Rigshospitalet, and Institute of Clinical Medicine, University of Copenhagen, Copenhagen, 2100 Denmark
| | - Bruce Appel
- Section of Developmental Biology, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - David S Rosenblatt
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada
| | - Tamim H Shaikh
- Section of Genetics, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA
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13
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Boulet A, Vest KE, Maynard MK, Gammon MG, Russell AC, Mathews AT, Cole SE, Zhu X, Phillips CB, Kwong JQ, Dodani SC, Leary SC, Cobine PA. The mammalian phosphate carrier SLC25A3 is a mitochondrial copper transporter required for cytochrome c oxidase biogenesis. J Biol Chem 2017; 293:1887-1896. [PMID: 29237729 DOI: 10.1074/jbc.ra117.000265] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 12/09/2017] [Indexed: 01/01/2023] Open
Abstract
Copper is required for the activity of cytochrome c oxidase (COX), the terminal electron-accepting complex of the mitochondrial respiratory chain. The likely source of copper used for COX biogenesis is a labile pool found in the mitochondrial matrix. In mammals, the proteins that transport copper across the inner mitochondrial membrane remain unknown. We previously reported that the mitochondrial carrier family protein Pic2 in budding yeast is a copper importer. The closest Pic2 ortholog in mammalian cells is the mitochondrial phosphate carrier SLC25A3. Here, to investigate whether SLC25A3 also transports copper, we manipulated its expression in several murine and human cell lines. SLC25A3 knockdown or deletion consistently resulted in an isolated COX deficiency in these cells, and copper addition to the culture medium suppressed these biochemical defects. Consistent with a conserved role for SLC25A3 in copper transport, its heterologous expression in yeast complemented copper-specific defects observed upon deletion of PIC2 Additionally, assays in Lactococcus lactis and in reconstituted liposomes directly demonstrated that SLC25A3 functions as a copper transporter. Taken together, these data indicate that SLC25A3 can transport copper both in vitro and in vivo.
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Affiliation(s)
- Aren Boulet
- From the Department of Biochemistry, University of Saskatchewan, Saskatoon, Saskatchewan 7N 5E5, Canada
| | - Katherine E Vest
- the Department of Biological Sciences, Auburn University, Auburn, Alabama 36849
| | - Margaret K Maynard
- the Department of Biological Sciences, Auburn University, Auburn, Alabama 36849
| | - Micah G Gammon
- the Department of Biological Sciences, Auburn University, Auburn, Alabama 36849
| | | | - Alexander T Mathews
- the Department of Biological Sciences, Auburn University, Auburn, Alabama 36849
| | - Shelbie E Cole
- the Department of Biological Sciences, Auburn University, Auburn, Alabama 36849
| | - Xinyu Zhu
- the Department of Biological Sciences, Auburn University, Auburn, Alabama 36849
| | - Casey B Phillips
- the Department of Biological Sciences, Auburn University, Auburn, Alabama 36849
| | - Jennifer Q Kwong
- Department of Pediatrics, Emory University, Atlanta, Georgia 30322, and
| | - Sheel C Dodani
- the Department of Chemistry and Biochemistry, University of Texas at Dallas, Dallas, Texas 75080
| | - Scot C Leary
- From the Department of Biochemistry, University of Saskatchewan, Saskatoon, Saskatchewan 7N 5E5, Canada
| | - Paul A Cobine
- the Department of Biological Sciences, Auburn University, Auburn, Alabama 36849,
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14
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Paakkola T, Vuopala K, Kokkonen H, Ignatius J, Valkama M, Moilanen JS, Fahiminiya S, Majewski J, Hinttala R, Uusimaa J. A homozygous I684T in GLE1 as a novel cause of arthrogryposis and motor neuron loss. Clin Genet 2017; 93:173-177. [PMID: 28657126 DOI: 10.1111/cge.13086] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 06/02/2017] [Accepted: 06/22/2017] [Indexed: 11/29/2022]
Abstract
Mutations in GLE1, RNA export mediator (GLE1) gene have previously been shown to cause motor neuron diseases such as lethal congenital contracture syndrome 1 (LCCS1) and lethal arthrogryposis with anterior horn cell disease (LAAHD), including arthrogryposis, fetal akinesis and motor neuron loss as common clinical features. The homozygous FinMajor mutation p.T144_E145insPFQ has been described as one of the causes for LCCS1 whereas LAAHD is caused by a heterocompound FinMajor mutation together with p.R569H, p.V617M or p.I684T missense mutation. None of these heterocompound missense mutations have previously been reported as homozygous states. Here we present the clinical features of 2 siblings with a homozygous p.I684T mutation in GLE1. The patients suffered from similar, but milder symptoms than in LCCS1 and LAAHD, surviving up to 6 months before they died due to a progressive disease course including respiratory failure. Arthrogryposis, lack of spontaneous movements, and epilepsy were notable in both cases and lack of anterior horn cells was identified in autopsy samples. Our studies on patient-derived fibroblasts show that the homozygous p.I684T impairs the nuclear localization of GLE1 further confirming the pathogenic role of this mutation.
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Affiliation(s)
- T Paakkola
- PEDEGO Research Unit, University of Oulu, Oulu, Finland.,Medical Research Center, University of Oulu, Oulu University Hospital, Oulu, Finland.,Biocenter Oulu, University of Oulu, Oulu, Finland
| | - K Vuopala
- Department of Pathology, Lapland Central Hospital, Rovaniemi, Finland
| | - H Kokkonen
- Northern Finland Laboratory Centre Nordlab and Medical Research Centre, Oulu University Hospital and University of Oulu, Oulu, Finland
| | - J Ignatius
- Department of Clinical Genetics, Oulu University Hospital, Oulu, Finland
| | - M Valkama
- PEDEGO Research Unit, University of Oulu, Oulu, Finland.,Medical Research Center, University of Oulu, Oulu University Hospital, Oulu, Finland.,Department of Children and Adolescents, Division of Pediatric Neurology, Oulu University Hospital, Oulu, Finland
| | - J S Moilanen
- PEDEGO Research Unit, University of Oulu, Oulu, Finland.,Medical Research Center, University of Oulu, Oulu University Hospital, Oulu, Finland.,Department of Clinical Genetics, Oulu University Hospital, Oulu, Finland
| | - S Fahiminiya
- Department of Human Genetics, McGill University, Montreal, Canada
| | - J Majewski
- Department of Human Genetics, McGill University, Montreal, Canada
| | - R Hinttala
- PEDEGO Research Unit, University of Oulu, Oulu, Finland.,Medical Research Center, University of Oulu, Oulu University Hospital, Oulu, Finland.,Biocenter Oulu, University of Oulu, Oulu, Finland
| | - J Uusimaa
- PEDEGO Research Unit, University of Oulu, Oulu, Finland.,Medical Research Center, University of Oulu, Oulu University Hospital, Oulu, Finland.,Biocenter Oulu, University of Oulu, Oulu, Finland.,Department of Children and Adolescents, Division of Pediatric Neurology, Oulu University Hospital, Oulu, Finland
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15
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Gentil BJ, O'Ferrall E, Chalk C, Santana LF, Durham HD, Massie R. A New Mutation in FIG4 Causes a Severe Form of CMT4J Involving TRPV4 in the Pathogenic Cascade. J Neuropathol Exp Neurol 2017; 76:789-799. [PMID: 28859335 DOI: 10.1093/jnen/nlx062] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Mutations in FIG4, coding for a phosphoinositol(3,5) bisphosphate 5' phosphatase and involved in vesicular trafficking and fusion, have been shown causing a recessive form of Charcot-Marie-Tooth (CMT). We have identified a novel intronic mutation in the FIG4 in a wheel-chair bound patient presenting with a severe form of CMT4J and provide a longitudinal study. Investigations indicated a demyelinating sensorimotor polyneuropathy with diffuse active denervation and severe axonal loss. Genetic testing revealed that the patient is heterozygous for 2 FIG4 mutations, p.I41T and a T > G transversion at IVS17-10, the latter predicted to cause a splicing defect. FIG4 was severely diminished in patient's fibroblasts indicating loss-of-function. Consistent with FIG4's function in phosphoinositol homeostasis and vesicular trafficking, fibroblasts contained multiple large vacuoles and vesicular organelles were abnormally dispersed. FIG4 deficiency has implications for turnover of membrane proteins. The transient receptor cation channel, TRPV4, accumulated at the plasma membrane of patient's fibroblasts due to slow turnover. Knocking down Fig4 in murine cultured motor neurons resulted in vacuolation and cell death. Inhibiting TRPV4 activity significantly preserved viability, although not correcting vesicular trafficking. In conclusion, we demonstrate a new FIG4 intronic mutation and, importantly, a functional interaction between FIG4 and TRPV4.
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Affiliation(s)
- Benoit J Gentil
- Department of Neurology and Neurosurgery & Montreal Neurological Institute, McGill University, Quebec, Canada; and Department of Physiology & Biophysics and Howard Hughes Medical Institute, Department of Pharmacology, University of Washington, Seattle, Washington
| | - Erin O'Ferrall
- Department of Neurology and Neurosurgery & Montreal Neurological Institute, McGill University, Quebec, Canada; and Department of Physiology & Biophysics and Howard Hughes Medical Institute, Department of Pharmacology, University of Washington, Seattle, Washington
| | - Colin Chalk
- Department of Neurology and Neurosurgery & Montreal Neurological Institute, McGill University, Quebec, Canada; and Department of Physiology & Biophysics and Howard Hughes Medical Institute, Department of Pharmacology, University of Washington, Seattle, Washington
| | - Luis F Santana
- Department of Neurology and Neurosurgery & Montreal Neurological Institute, McGill University, Quebec, Canada; and Department of Physiology & Biophysics and Howard Hughes Medical Institute, Department of Pharmacology, University of Washington, Seattle, Washington
| | - Heather D Durham
- Department of Neurology and Neurosurgery & Montreal Neurological Institute, McGill University, Quebec, Canada; and Department of Physiology & Biophysics and Howard Hughes Medical Institute, Department of Pharmacology, University of Washington, Seattle, Washington
| | - Rami Massie
- Department of Neurology and Neurosurgery & Montreal Neurological Institute, McGill University, Quebec, Canada; and Department of Physiology & Biophysics and Howard Hughes Medical Institute, Department of Pharmacology, University of Washington, Seattle, Washington
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16
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Newly born peroxisomes are a hybrid of mitochondrial and ER-derived pre-peroxisomes. Nature 2017; 542:251-254. [PMID: 28146471 DOI: 10.1038/nature21375] [Citation(s) in RCA: 262] [Impact Index Per Article: 37.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 01/10/2017] [Indexed: 01/24/2023]
Abstract
Peroxisomes function together with mitochondria in a number of essential biochemical pathways, from bile acid synthesis to fatty acid oxidation. Peroxisomes grow and divide from pre-existing organelles, but can also emerge de novo in the cell. The physiological regulation of de novo peroxisome biogenesis remains unclear, and it is thought that peroxisomes emerge from the endoplasmic reticulum in both mammalian and yeast cells. However, in contrast to the yeast system, a number of integral peroxisomal membrane proteins are imported into mitochondria in mammalian cells in the absence of peroxisomes, including Pex3, Pex12, Pex13, Pex14, Pex26, PMP34 and ALDP. Overall, the mitochondrial localization of peroxisomal membrane proteins in mammalian cells has largely been considered a mis-targeting artefact in which de novo biogenesis occurs exclusively from endoplasmic reticulum-targeted peroxins. Here, in following the generation of new peroxisomes within human patient fibroblasts lacking peroxisomes, we show that the essential import receptors Pex3 and Pex14 target mitochondria, where they are selectively released into vesicular pre-peroxisomal structures. Maturation of pre-peroxisomes containing Pex3 and Pex14 requires fusion with endoplasmic reticulum-derived vesicles carrying Pex16, thereby providing full import competence. These findings demonstrate the hybrid nature of newly born peroxisomes, expanding their functional links to mitochondria.
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17
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Bourens M, Barrientos A. A CMC1-knockout reveals translation-independent control of human mitochondrial complex IV biogenesis. EMBO Rep 2017; 18:477-494. [PMID: 28082314 DOI: 10.15252/embr.201643103] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 11/25/2016] [Accepted: 12/02/2016] [Indexed: 11/09/2022] Open
Abstract
Defects in mitochondrial respiratory chain complex IV (CIV) frequently cause encephalocardiomyopathies. Human CIV assembly involves 14 subunits of dual genetic origin and multiple nucleus-encoded ancillary factors. Biogenesis of the mitochondrion-encoded copper/heme-containing COX1 subunit initiates the CIV assembly process. Here, we show that the intermembrane space twin CX9C protein CMC1 forms an early CIV assembly intermediate with COX1 and two assembly factors, the cardiomyopathy proteins COA3 and COX14. A TALEN-mediated CMC1 knockout HEK293T cell line displayed normal COX1 synthesis but decreased CIV activity owing to the instability of newly synthetized COX1. We demonstrate that CMC1 stabilizes a COX1-COA3-COX14 complex before the incorporation of COX4 and COX5a subunits. Additionally, we show that CMC1 acts independently of CIV assembly factors relevant to COX1 metallation (COX10, COX11, and SURF1) or late stability (MITRAC7). Furthermore, whereas human COX14 and COA3 have been proposed to affect COX1 mRNA translation, our data indicate that CMC1 regulates turnover of newly synthesized COX1 prior to and during COX1 maturation, without affecting the rate of COX1 synthesis.
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Affiliation(s)
- Myriam Bourens
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Antoni Barrientos
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA .,Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, USA
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18
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Hartmann B, Wai T, Hu H, MacVicar T, Musante L, Fischer-Zirnsak B, Stenzel W, Gräf R, van den Heuvel L, Ropers HH, Wienker TF, Hübner C, Langer T, Kaindl AM. Homozygous YME1L1 mutation causes mitochondriopathy with optic atrophy and mitochondrial network fragmentation. eLife 2016; 5. [PMID: 27495975 PMCID: PMC4991934 DOI: 10.7554/elife.16078] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 07/28/2016] [Indexed: 11/13/2022] Open
Abstract
Mitochondriopathies often present clinically as multisystemic disorders of primarily high-energy consuming organs. Assembly, turnover, and surveillance of mitochondrial proteins are essential for mitochondrial function and a key task of AAA family members of metalloproteases. We identified a homozygous mutation in the nuclear encoded mitochondrial escape 1-like 1 gene YME1L1, member of the AAA protease family, as a cause of a novel mitochondriopathy in a consanguineous pedigree of Saudi Arabian descent. The homozygous missense mutation, located in a highly conserved region in the mitochondrial pre-sequence, inhibits cleavage of YME1L1 by the mitochondrial processing peptidase, which culminates in the rapid degradation of YME1L1 precursor protein. Impaired YME1L1 function causes a proliferation defect and mitochondrial network fragmentation due to abnormal processing of OPA1. Our results identify mutations in YME1L1 as a cause of a mitochondriopathy with optic nerve atrophy highlighting the importance of YME1L1 for mitochondrial functionality in humans.
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Affiliation(s)
- Bianca Hartmann
- Institute of Cell Biology and Neurobiology, Charité University Medicine, Berlin, Germany.,Department of Pediatric Neurology, Charité University Medicine, Berlin, Germany.,Sozialpädiatrisches Zentrum (SPZ), Center for Chronically Sick Children, Charité University Medicine, Berlin, Germany
| | - Timothy Wai
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Cologne, Germany
| | - Hao Hu
- Max Planck Institute for Molecular Genetics, Berlin, Germany.,Guangzhou Women and Children's Medical Center, Guangzhou, China
| | - Thomas MacVicar
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Cologne, Germany
| | - Luciana Musante
- Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Björn Fischer-Zirnsak
- Max Planck Institute for Molecular Genetics, Berlin, Germany.,Institut of Medical Genetics and Human Genetics, Charité University Medicine, Berlin, Germany
| | - Werner Stenzel
- Institute of Neuropathology, Charité University Medicine, Berlin, Germany
| | - Ralph Gräf
- Department of Cell Biology, University of Potsdam, Potsdam, Germany
| | - Lambert van den Heuvel
- Nijmegen Center for Mitochondrial Disorders, Radboud University Medical Center, Nijmegen, Netherlands
| | | | | | - Christoph Hübner
- Department of Pediatric Neurology, Charité University Medicine, Berlin, Germany
| | - Thomas Langer
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Cologne, Germany
| | - Angela M Kaindl
- Institute of Cell Biology and Neurobiology, Charité University Medicine, Berlin, Germany.,Department of Pediatric Neurology, Charité University Medicine, Berlin, Germany.,Sozialpädiatrisches Zentrum (SPZ), Center for Chronically Sick Children, Charité University Medicine, Berlin, Germany
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19
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Pharaoh G, Pulliam D, Hill S, Sataranatarajan K, Van Remmen H. Ablation of the mitochondrial complex IV assembly protein Surf1 leads to increased expression of the UPR(MT) and increased resistance to oxidative stress in primary cultures of fibroblasts. Redox Biol 2016; 8:430-8. [PMID: 27208630 PMCID: PMC4878459 DOI: 10.1016/j.redox.2016.05.001] [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: 04/27/2016] [Revised: 05/03/2016] [Accepted: 05/06/2016] [Indexed: 11/24/2022] Open
Abstract
Mice deficient in the electron transport chain (ETC) complex IV assembly protein SURF1 have reduced assembly and activity of cytochrome c oxidase that is associated with an upregulation of components of the mitochondrial unfolded protein response (UPRMT) and increased mitochondrial number. We hypothesized that the upregulation of proteins associated with the UPRMT in response to reduced cytochrome c oxidase activity in Surf1−/− mice might contribute to increased stress resistance. To test this hypothesis we asked whether primary cultures of fibroblasts from Surf1−/− mice exhibit enhanced resistance to stressors compared to wild-type fibroblasts. Here we show that primary dermal fibroblasts isolated from Surf1−/− mice have increased expression of UPRMT components ClpP and Hsp60, and increased expression of Lon protease. Fibroblasts from Surf1−/− mice are significantly more resistant to cell death caused by oxidative stress induced by paraquat or tert-Butyl hydroperoxide compared to cells from wild-type mice. In contrast, Surf1−/− fibroblasts show no difference in sensitivity to hydrogen peroxide stress. The enhanced cell survival in response to paraquat or tert-Butyl hydroperoxide in Surf1−/− fibroblasts compared to wild-type fibroblasts is associated with induced expression of Lon, ClpP, and Hsp60, increased maximal respiration, and increased reserve capacity as measured using the Seahorse Extracellular Flux Analyzer. Overall these data support a protective role for the activation of the UPRMT in cell survival. Surf1−/− mice fibroblasts exhibit upregulation of proteins involved in the UPRMT. Mitochondrial specific oxidative stressors induce UPRMT in mammalian fibroblasts. Surf1−/− fibroblasts exhibit enhanced mitochondrial specific stress resistance. Surf1−/− fibroblasts have increased maximal respiration and respiratory reserve.
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Affiliation(s)
- Gavin Pharaoh
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, 825 NE 13th St, Oklahoma City, OK 73104, United States; Department of Physiology, Oklahoma University Health Science Center, 940 S.L. Young Blvd, Oklahoma City, OK 73104, United States
| | - Daniel Pulliam
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, 825 NE 13th St, Oklahoma City, OK 73104, United States; Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr, San Antonio, TX 78229, United States
| | - Shauna Hill
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, 825 NE 13th St, Oklahoma City, OK 73104, United States; Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr, San Antonio, TX 78229, United States
| | - Kavithalakshmi Sataranatarajan
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, 825 NE 13th St, Oklahoma City, OK 73104, United States
| | - Holly Van Remmen
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, 825 NE 13th St, Oklahoma City, OK 73104, United States; Oklahoma City VA Medical Center, 921 NE 13th St, Oklahoma City, OK 73104, United States; Department of Physiology, Oklahoma University Health Science Center, 940 S.L. Young Blvd, Oklahoma City, OK 73104, United States.
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20
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Kovářová N, Pecina P, Nůsková H, Vrbacký M, Zeviani M, Mráček T, Viscomi C, Houštěk J. Tissue- and species-specific differences in cytochrome c oxidase assembly induced by SURF1 defects. Biochim Biophys Acta Mol Basis Dis 2016; 1862:705-715. [PMID: 26804654 PMCID: PMC4793088 DOI: 10.1016/j.bbadis.2016.01.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 12/08/2015] [Accepted: 01/08/2016] [Indexed: 12/17/2022]
Abstract
Mitochondrial protein SURF1 is a specific assembly factor of cytochrome c oxidase (COX), but its function is poorly understood. SURF1 gene mutations cause a severe COX deficiency manifesting as the Leigh syndrome in humans, whereas in mice SURF1−/− knockout leads only to a mild COX defect. We used SURF1−/− mouse model for detailed analysis of disturbed COX assembly and COX ability to incorporate into respiratory supercomplexes (SCs) in different tissues and fibroblasts. Furthermore, we compared fibroblasts from SURF1−/− mouse and SURF1 patients to reveal interspecies differences in kinetics of COX biogenesis using 2D electrophoresis, immunodetection, arrest of mitochondrial proteosynthesis and pulse-chase metabolic labeling. The crucial differences observed are an accumulation of abundant COX1 assembly intermediates, low content of COX monomer and preferential recruitment of COX into I–III2–IVn SCs in SURF1 patient fibroblasts, whereas SURF1−/− mouse fibroblasts were characterized by low content of COX1 assembly intermediates and milder decrease in COX monomer, which appeared more stable. This pattern was even less pronounced in SURF1−/− mouse liver and brain. Both the control and SURF1−/− mice revealed only negligible formation of the I–III2–IVn SCs and marked tissue differences in the contents of COX dimer and III2–IV SCs, also less noticeable in liver and brain than in heart and muscle. Our studies support the view that COX assembly is much more dependent on SURF1 in humans than in mice. We also demonstrate markedly lower ability of mouse COX to form I–III2–IVn supercomplexes, pointing to tissue-specific and species-specific differences in COX biogenesis. In SURF1 −/− mouse the decrease of COX amount and activity was tissue/cell specific. Assembly kinetics proceeded to the level of stable COX monomer in SURF1 −/− mouse. COX assembly intermediates were faster degraded/depleted in time in SURF1 −/− mouse. COX was preferentially recruited in supercomplex I–III2–IV1 in SURF1 patient cells. Newly synthesized COX monomer was unstable and rapidly degraded in SURF1 patient.
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Affiliation(s)
- Nikola Kovářová
- Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1083, Prague, Czech Republic
| | - Petr Pecina
- Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1083, Prague, Czech Republic
| | - Hana Nůsková
- Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1083, Prague, Czech Republic
| | - Marek Vrbacký
- Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1083, Prague, Czech Republic
| | - Massimo Zeviani
- Molecular Neurogenetics Unit, Instituto Neurologico "C. Besta", via Temolo 4, 20126 Milan, Italy; MRC-Mitochondrial Biology Unit, Wellcome Trust MRC Bldg, Addenbrookes Hospital Hills Rd, Cambridge CB2 0XY, UK
| | - Tomáš Mráček
- Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1083, Prague, Czech Republic
| | - Carlo Viscomi
- MRC-Mitochondrial Biology Unit, Wellcome Trust MRC Bldg, Addenbrookes Hospital Hills Rd, Cambridge CB2 0XY, UK
| | - Josef Houštěk
- Institute of Physiology of the Czech Academy of Sciences, Vídeňská 1083, Prague, Czech Republic.
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21
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Cooperation between COA6 and SCO2 in COX2 maturation during cytochrome c oxidase assembly links two mitochondrial cardiomyopathies. Cell Metab 2015; 21:823-33. [PMID: 25959673 DOI: 10.1016/j.cmet.2015.04.012] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 03/03/2015] [Accepted: 04/04/2015] [Indexed: 11/20/2022]
Abstract
Three mitochondria-encoded subunits form the catalytic core of cytochrome c oxidase, the terminal enzyme of the respiratory chain. COX1 and COX2 contain heme and copper redox centers, which are integrated during assembly of the enzyme. Defects in this process lead to an enzyme deficiency and manifest as mitochondrial disorders in humans. Here we demonstrate that COA6 is specifically required for COX2 biogenesis. Absence of COA6 leads to fast turnover of newly synthesized COX2 and a concomitant reduction in cytochrome c oxidase levels. COA6 interacts transiently with the copper-containing catalytic domain of newly synthesized COX2. Interestingly, similar to the copper metallochaperone SCO2, loss of COA6 causes cardiomyopathy in humans. We show that COA6 and SCO2 interact and that corresponding pathogenic mutations in each protein affect complex formation. Our analyses define COA6 as a constituent of the mitochondrial copper relay system, linking defects in COX2 metallation to cardiac cytochrome c oxidase deficiency.
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22
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Burelle Y, Bemeur C, Rivard ME, Thompson Legault J, Boucher G, Morin C, Coderre L, Des Rosiers C. Mitochondrial vulnerability and increased susceptibility to nutrient-induced cytotoxicity in fibroblasts from leigh syndrome French canadian patients. PLoS One 2015; 10:e0120767. [PMID: 25835550 PMCID: PMC4383560 DOI: 10.1371/journal.pone.0120767] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 02/07/2015] [Indexed: 01/20/2023] Open
Abstract
Mutations in LRPPRC are responsible for the French Canadian variant of Leigh Syndrome (LSFC), a severe disorder characterized biochemically by a tissue-specific deficiency of cytochrome c oxidase (COX) and clinically by the occurrence of severe and deadly acidotic crises. Factors that precipitate these crises remain unclear. To better understand the physiopathology and identify potential treatments, we performed a comprehensive analysis of mitochondrial function in LSFC and control fibroblasts. Furthermore, we have used this cell-based model to screen for conditions that promote premature cell death in LSFC cells and test the protective effect of ten interventions targeting well-defined aspects of mitochondrial function. We show that, despite maintaining normal ATP levels, LSFC fibroblasts present several mitochondrial functional abnormalities under normal baseline conditions, which likely impair their capacity to respond to stress. This includes mitochondrial network fragmentation, impaired oxidative phosphorylation capacity, lower membrane potential, increased sensitivity to Ca2+-induced permeability transition, but no changes in reactive oxygen species production. We also show that LSFC fibroblasts display enhanced susceptibility to cell death when exposed to palmitate, an effect that is potentiated by high lactate, while high glucose or acidosis alone or in combination were neutral. Furthermore, we demonstrate that compounds that are known to promote flux through the electron transport chain independent of phosphorylation (methylene blue, dinitrophenol), or modulate fatty acid (L-carnitine) or Krebs cycle metabolism (propionate) are protective, while antioxidants (idebenone, N-acetyl cysteine, resveratrol) exacerbate palmitate plus lactate-induced cell death. Collectively, beyond highlighting multiple alterations in mitochondrial function and increased susceptibility to nutrient-induced cytotoxicity in LSFC fibroblasts, these results raise questions about the nature of the diets, particularly excess fat intake, as well as on the use of antioxidants in patients with LSFC and, possibly, other COX defects.
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Affiliation(s)
- Yan Burelle
- Faculty of Pharmacy, Université de Montréal, Montréal, Canada
| | - Chantal Bemeur
- Faculty of Pharmacy, Université de Montréal, Montréal, Canada
| | - Marie-Eve Rivard
- Montreal Heart Institute, Montreal, Canada
- Department of Nutrition, Faculty of Medicine, Université de Montréal, Montreal, Canada
| | - Julie Thompson Legault
- Montreal Heart Institute, Montreal, Canada
- Department of Nutrition, Faculty of Medicine, Université de Montréal, Montreal, Canada
| | | | | | - Charles Morin
- Department of Pediatrics and Clinical Research Unit, Complexe hospitalier de la Sagamie, Chicoutimi, QC, Canada
| | - Lise Coderre
- Montreal Heart Institute, Montreal, Canada
- Department of Nutrition, Faculty of Medicine, Université de Montréal, Montreal, Canada
- Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, Canada
| | - Christine Des Rosiers
- Montreal Heart Institute, Montreal, Canada
- Department of Nutrition, Faculty of Medicine, Université de Montréal, Montreal, Canada
- * E-mail:
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23
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Ostergaard E, Weraarpachai W, Ravn K, Born AP, Jønson L, Duno M, Wibrand F, Shoubridge EA, Vissing J. Mutations in COA3 cause isolated complex IV deficiency associated with neuropathy, exercise intolerance, obesity, and short stature. J Med Genet 2015; 52:203-7. [PMID: 25604084 DOI: 10.1136/jmedgenet-2014-102914] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND We investigated a subject with an isolated cytochrome c oxidase (COX) deficiency presenting with an unusual phenotype characterised by neuropathy, exercise intolerance, obesity, and short stature. METHODS AND RESULTS Blue-native polyacrylamide gel electrophoresis (BN-PAGE) analysis showed an almost complete lack of COX assembly in subject fibroblasts, consistent with the very low enzymatic activity, and pulse-labelling mitochondrial translation experiments showed a specific decrease in synthesis of the COX1 subunit, the core catalytic subunit that nucleates assembly of the holoenzyme. Whole exome sequencing identified compound heterozygous mutations (c.199dupC, c.215A>G) in COA3, a small inner membrane COX assembly factor, resulting in a pronounced decrease in the steady-state levels of COA3 protein. Retroviral expression of a wild-type COA3 cDNA completely rescued the COX assembly and mitochondrial translation defects, confirming the pathogenicity of the mutations, and resulted in increased steady-state levels of COX1 in control cells, demonstrating a role for COA3 in the stabilisation of this subunit. COA3 exists in an early COX assembly complex that contains COX1 and other COX assembly factors including COX14 (C12orf62), another single pass transmembrane protein that also plays a role in coupling COX1 synthesis with holoenzyme assembly. Immunoblot analysis showed that COX14 was undetectable in COA3 subject fibroblasts, and that COA3 was undetectable in fibroblasts from a COX14 subject, demonstrating the interdependence of these two COX assembly factors. CONCLUSIONS The mild clinical course in this patient contrasts with nearly all other cases of severe COX assembly defects that are usually fatal early in life, and underscores the marked tissue-specific involvement in mitochondrial diseases.
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Affiliation(s)
- Elsebet Ostergaard
- Department of Clinical Genetics, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Woranontee Weraarpachai
- Department of Human Genetics and Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada, Department of Biochemistry, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Kirstine Ravn
- Department of Clinical Genetics, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Alfred Peter Born
- Department of Pediatrics, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Lars Jønson
- Department of Genomic Medicine, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Morten Duno
- Department of Clinical Genetics, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Flemming Wibrand
- Department of Clinical Genetics, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Eric A Shoubridge
- Department of Human Genetics and Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - John Vissing
- Department of Neurology and Neuromuscular Research Unit, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark
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24
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Schwartzentruber J, Buhas D, Majewski J, Sasarman F, Papillon-Cavanagh S, Thiffault I, Thiffaut I, Sheldon KM, Massicotte C, Patry L, Simon M, Zare AS, McKernan KJ, Michaud J, Boles RG, Deal CL, Desilets V, Shoubridge EA, Samuels ME. Mutation in the nuclear-encoded mitochondrial isoleucyl-tRNA synthetase IARS2 in patients with cataracts, growth hormone deficiency with short stature, partial sensorineural deafness, and peripheral neuropathy or with Leigh syndrome. Hum Mutat 2014; 35:1285-9. [PMID: 25130867 DOI: 10.1002/humu.22629] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 07/10/2014] [Indexed: 01/28/2023]
Abstract
Mutations in the nuclear-encoded mitochondrial aminoacyl-tRNA synthetases are associated with a range of clinical phenotypes. Here, we report a novel disorder in three adult patients with a phenotype including cataracts, short-stature secondary to growth hormone deficiency, sensorineural hearing deficit, peripheral sensory neuropathy, and skeletal dysplasia. Using SNP genotyping and whole-exome sequencing, we identified a single likely causal variant, a missense mutation in a conserved residue of the nuclear gene IARS2, encoding mitochondrial isoleucyl-tRNA synthetase. The mutation is homozygous in the affected patients, heterozygous in carriers, and absent in control chromosomes. IARS2 protein level was reduced in skin cells cultured from one of the patients, consistent with a pathogenic effect of the mutation. Compound heterozygous mutations in IARS2 were independently identified in a previously unreported patient with a more severe mitochondrial phenotype diagnosed as Leigh syndrome. This is the first report of clinical findings associated with IARS2 mutations.
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25
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Da-Rè C, von Stockum S, Biscontin A, Millino C, Cisotto P, Zordan MA, Zeviani M, Bernardi P, De Pittà C, Costa R. Leigh syndrome in Drosophila melanogaster: morphological and biochemical characterization of Surf1 post-transcriptional silencing. J Biol Chem 2014; 289:29235-46. [PMID: 25164807 PMCID: PMC4200275 DOI: 10.1074/jbc.m114.602938] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 08/26/2014] [Indexed: 01/20/2023] Open
Abstract
Leigh Syndrome (LS) is the most common early-onset, progressive mitochondrial encephalopathy usually leading to early death. The single most prevalent cause of LS is occurrence of mutations in the SURF1 gene, and LS(Surf1) patients show a ubiquitous and specific decrease in the activity of mitochondrial respiratory chain complex IV (cytochrome c oxidase, COX). SURF1 encodes an inner membrane mitochondrial protein involved in COX assembly. We established a Drosophila melanogaster model of LS based on the post-transcriptional silencing of CG9943, the Drosophila homolog of SURF1. Knockdown of Surf1 was induced ubiquitously in larvae and adults, which led to lethality; in the mesodermal derivatives, which led to pupal lethality; or in the central nervous system, which allowed survival. A biochemical characterization was carried out in knockdown individuals, which revealed that larvae unexpectedly displayed defects in all complexes of the mitochondrial respiratory chain and in the F-ATP synthase, while adults had a COX-selective impairment. Silencing of Surf1 expression in Drosophila S2R(+) cells led to selective loss of COX activity associated with decreased oxygen consumption and respiratory reserve. We conclude that Surf1 is essential for COX activity and mitochondrial function in D. melanogaster, thus providing a new tool that may help clarify the pathogenic mechanisms of LS.
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Affiliation(s)
| | | | | | - Caterina Millino
- CRIBI Biotechnology Centre, University of Padova, 35121 Padova, Italy and
| | | | | | - Massimo Zeviani
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, United Kingdom
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26
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Milone M, Wong LJ. Diagnosis of mitochondrial myopathies. Mol Genet Metab 2013; 110:35-41. [PMID: 23911206 DOI: 10.1016/j.ymgme.2013.07.007] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Revised: 07/10/2013] [Accepted: 07/10/2013] [Indexed: 01/01/2023]
Abstract
Mitochondria are ubiquitous organelles and play crucial roles in vital functions, most importantly, the oxidative phosphorylation and energy metabolism. Therefore, mitochondrial dysfunction can affect multiple tissues, with muscle and nerve preferentially affected. Mitochondrial myopathy is a common clinical phenotype, which is characterized by early fatigue and/or fixed muscle weakness; rhabdomyolysis can seldom occur. Muscle biopsy often identifies signs of diseased mitochondria by morphological studies, while biochemical analysis may identify respiratory chain deficiencies. The clinical, morphological and biochemical data guide molecular analysis. Being the mitochondrial function under the control of both mitochondrial DNA and nuclear DNA, the search for mitochondrial DNA mutations and mitochondrial DNA quantitation, may not be sufficient for the molecular diagnosis of mitochondrial myopathies. Approximately 1500 nuclear genes can affect mitochondrial structure and function and the targeting of such genes may be necessary to reach the diagnosis. The identification of causative molecular defects in nuclear or mitochondrial genome leads to the definite diagnosis of mitochondrial myopathy.
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Affiliation(s)
- Margherita Milone
- Department of Neurology, Neuromuscular Division, Mayo Clinic, Rochester, MN, USA
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27
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Hewitt VL, Gabriel K, Traven A. The ins and outs of the intermembrane space: diverse mechanisms and evolutionary rewiring of mitochondrial protein import routes. Biochim Biophys Acta Gen Subj 2013; 1840:1246-53. [PMID: 23994494 DOI: 10.1016/j.bbagen.2013.08.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Revised: 08/09/2013] [Accepted: 08/20/2013] [Indexed: 11/24/2022]
Abstract
BACKGROUND Mitochondrial biogenesis is an essential process in all eukaryotes. Import of proteins from the cytosol into mitochondria is a key step in organelle biogenesis. Recent evidence suggests that a given mitochondrial protein does not take the same import route in all organisms, suggesting that pathways of mitochondrial protein import can be rewired through evolution. Examples of this process so far involve proteins destined to the mitochondrial intermembrane space (IMS). SCOPE OF REVIEW Here we review the components, substrates and energy sources of the known mechanisms of protein import into the IMS. We discuss evolutionary rewiring of the IMS import routes, focusing on the example of the lactate utilisation enzyme cytochrome b2 (Cyb2) in the model yeast Saccharomyces cerevisiae and the human fungal pathogen Candida albicans. MAJOR CONCLUSIONS There are multiple import pathways used for protein entry into the IMS and they form a network capable of importing a diverse range of substrates. These pathways have been rewired, possibly in response to environmental pressures, such as those found in the niches in the human body inhabited by C. albicans. GENERAL SIGNIFICANCE We propose that evolutionary rewiring of mitochondrial import pathways can adjust the metabolic fitness of a given species to their environmental niche. This article is part of a Special Issue entitled Frontiers of Mitochondrial.
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Affiliation(s)
- Victoria L Hewitt
- Department of Biochemistry and Molecular Biology, Building 77, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne 3800, Australia.
| | - Kipros Gabriel
- Department of Biochemistry and Molecular Biology, Building 77, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne 3800, Australia.
| | - Ana Traven
- Department of Biochemistry and Molecular Biology, Building 77, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne 3800, Australia.
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28
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Antonicka H, Sasarman F, Nishimura T, Paupe V, Shoubridge EA. The mitochondrial RNA-binding protein GRSF1 localizes to RNA granules and is required for posttranscriptional mitochondrial gene expression. Cell Metab 2013; 17:386-98. [PMID: 23473033 DOI: 10.1016/j.cmet.2013.02.006] [Citation(s) in RCA: 160] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 12/18/2012] [Accepted: 02/06/2013] [Indexed: 10/27/2022]
Abstract
RNA-binding proteins are at the heart of posttranscriptional gene regulation, coordinating the processing, storage, and handling of cellular RNAs. We show here that GRSF1, previously implicated in the binding and selective translation of influenza mRNAs, is targeted to mitochondria where it forms granules that colocalize with foci of newly synthesized mtRNA next to mitochondrial nucleoids. GRSF1 preferentially binds RNAs transcribed from three contiguous genes on the light strand of mtDNA, the ND6 mRNA, and the long noncoding RNAs for cytb and ND5, each of which contains multiple consensus binding sequences. RNAi-mediated knockdown of GRSF1 leads to alterations in mitochondrial RNA stability, abnormal loading of mRNAs and lncRNAs on the mitochondrial ribosome, and impaired ribosome assembly. This results in a specific protein synthesis defect and a failure to assemble normal amounts of the oxidative phosphorylation complexes. These data implicate GRSF1 as a key regulator of posttranscriptional mitochondrial gene expression.
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Affiliation(s)
- Hana Antonicka
- Montreal Neurological Institute and Department of Human Genetics, McGill University, Montreal, QC H3A 2B4, Canada
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Richter U, Lahtinen T, Marttinen P, Myöhänen M, Greco D, Cannino G, Jacobs H, Lietzén N, Nyman T, Battersby B. A Mitochondrial Ribosomal and RNA Decay Pathway Blocks Cell Proliferation. Curr Biol 2013; 23:535-41. [DOI: 10.1016/j.cub.2013.02.019] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 01/21/2013] [Accepted: 02/08/2013] [Indexed: 12/28/2022]
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The channel-forming Sym1 protein is transported by the TIM23 complex in a presequence-independent manner. Mol Cell Biol 2012; 32:5009-21. [PMID: 23045398 DOI: 10.1128/mcb.00843-12] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The majority of multispanning inner mitochondrial membrane proteins utilize internal targeting signals, which direct them to the carrier translocase (TIM22 complex), for their import. MPV17 and its Saccharomyces cerevisiae orthologue Sym1 are multispanning inner membrane proteins of unknown function with an amino-terminal presequence that suggests they may be targeted to the mitochondria. Mutations affecting MPV17 are associated with mitochondrial DNA depletion syndrome (MDDS). Reconstitution of purified Sym1 into planar lipid bilayers and electrophysiological measurements have demonstrated that Sym1 forms a membrane pore. To address the biogenesis of Sym1, which oligomerizes in the inner mitochondrial membrane, we studied its import and assembly pathway. Sym1 forms a transport intermediate at the translocase of the outer membrane (TOM) complex. Surprisingly, Sym1 was not transported into mitochondria by an amino-terminal signal, and in contrast to what has been observed in carrier proteins, Sym1 transport and assembly into the inner membrane were independent of small translocase of mitochondrial inner membrane (TIM) and TIM22 complexes. Instead, Sym1 required the presequence of translocase for its biogenesis. Our analyses have revealed a novel transport mechanism for a polytopic membrane protein in which internal signals direct the precursor into the inner membrane via the TIM23 complex, indicating a presequence-independent function of this translocase.
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Janer A, Antonicka H, Lalonde E, Nishimura T, Sasarman F, Brown GK, Brown RM, Majewski J, Shoubridge EA. An RMND1 Mutation causes encephalopathy associated with multiple oxidative phosphorylation complex deficiencies and a mitochondrial translation defect. Am J Hum Genet 2012; 91:737-43. [PMID: 23022098 DOI: 10.1016/j.ajhg.2012.08.020] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 08/03/2012] [Accepted: 08/21/2012] [Indexed: 11/29/2022] Open
Abstract
Mutations in the genes composing the mitochondrial translation apparatus are an important cause of a heterogeneous group of oxidative phosphorylation (OXPHOS) disorders. We studied the index case in a consanguineous family in which two children presented with severe encephalopathy, lactic acidosis, and intractable seizures leading to an early fatal outcome. Blue native polyacrylamide gel electrophoretic (BN-PAGE) analysis showed assembly defects in all of the OXPHOS complexes with mtDNA-encoded structural subunits, and these defects were associated with a severe deficiency in mitochondrial translation. Immunoblot analysis showed reductions in the steady-state levels of several structural subunits of the mitochondrial ribosome. Whole-exome sequencing identified a homozygous missense mutation (c.1250G>A) in an uncharacterized gene, RMND1 (required for meiotic nuclear division 1). RMND1 localizes to mitochondria and behaves as an integral membrane protein. Retroviral expression of the wild-type RMND1 cDNA rescued the biochemical phenotype in subject cells, and siRNA-mediated knockdown of the protein recapitulated the defect. BN-PAGE, gel filtration, and mass spectrometry analyses showed that RMND1 forms a high-molecular-weight and most likely homopolymeric complex (∼240 kDa) that does not assemble in subject fibroblasts but that is rescued by expression of RMND1 cDNA. The p.Arg417Gln substitution, predicted to be in a coiled-coil domain, which is juxtaposed to a transmembrane domain at the extreme C terminus of the protein, does not alter the steady-state level of RMND1 but might prevent protein-protein interactions in this complex. Our results demonstrate that the RMND1 complex is necessary for mitochondrial translation, possibly by coordinating the assembly or maintenance of the mitochondrial ribosome.
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Affiliation(s)
- Alexandre Janer
- Department of Human Genetics, McGill University, 1205 Penfield Avenue, Montréal, QC H3A 1B1, Canada
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Coelho D, Kim JC, Miousse IR, Fung S, du Moulin M, Buers I, Suormala T, Burda P, Frapolli M, Stucki M, Nürnberg P, Thiele H, Robenek H, Höhne W, Longo N, Pasquali M, Mengel E, Watkins D, Shoubridge EA, Majewski J, Rosenblatt DS, Fowler B, Rutsch F, Baumgartner MR. Mutations in ABCD4 cause a new inborn error of vitamin B12 metabolism. Nat Genet 2012; 44:1152-5. [PMID: 22922874 DOI: 10.1038/ng.2386] [Citation(s) in RCA: 148] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 07/20/2012] [Indexed: 12/12/2022]
Abstract
Inherited disorders of vitamin B12 (cobalamin) have provided important clues to how this vitamin, which is essential for hematological and neurological function, is transported and metabolized. We describe a new disease that results in failure to release vitamin B12 from lysosomes, which mimics the cblF defect caused by LMBRD1 mutations. Using microcell-mediated chromosome transfer and exome sequencing, we identified causal mutations in ABCD4, a gene that codes for an ABC transporter, which was previously thought to have peroxisomal localization and function. Our results show that ABCD4 colocalizes with the lysosomal proteins LAMP1 and LMBD1, the latter of which is deficient in the cblF defect. Furthermore, we show that mutations altering the putative ATPase domain of ABCD4 affect its function, suggesting that the ATPase activity of ABCD4 may be involved in intracellular processing of vitamin B12.
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Affiliation(s)
- David Coelho
- Division of Metabolism, Children's Research Center (CRC), University Children's Hospital, Zürich, Switzerland
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Lee IC, El-Hattab AW, Wang J, Li FY, Weng SW, Craigen WJ, Wong LJC. SURF1-associated leigh syndrome: A case series and novel mutations. Hum Mutat 2012; 33:1192-200. [DOI: 10.1002/humu.22095] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2011] [Accepted: 03/15/2012] [Indexed: 11/11/2022]
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Adaptation of respiratory chain biogenesis to cytochrome c oxidase deficiency caused by SURF1 gene mutations. Biochim Biophys Acta Mol Basis Dis 2012; 1822:1114-24. [PMID: 22465034 DOI: 10.1016/j.bbadis.2012.03.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Revised: 03/09/2012] [Accepted: 03/12/2012] [Indexed: 01/26/2023]
Abstract
The loss of Surf1 protein leads to a severe COX deficiency manifested as a fatal neurodegenerative disorder, the Leigh syndrome (LS(COX)). Surf1 appears to be involved in the early step of COX assembly but its function remains unknown. The aim of the study was to find out how SURF1 gene mutations influence expression of OXPHOS and other pro-mitochondrial genes and to further characterize the altered COX assembly. Analysis of fibroblast cell lines from 9 patients with SURF1 mutations revealed a 70% decrease of the COX complex content to be associated with 32-54% upregulation of respiratory chain complexes I, III and V and accumulation of Cox5a subunit. Whole genome expression profiling showed a general decrease of transcriptional activity in LS(COX) cells and indicated that the adaptive changes in OXPHOS complexes are due to a posttranscriptional compensatory mechanism. Electrophoretic and WB analysis showed that in mitochondria of LS(COX) cells compared to controls, the assembled COX is present entirely in a supercomplex form, as I-III₂-IV supercomplex but not as larger supercomplexes. The lack of COX also caused an accumulation of I-III₂ supercomplex. The accumulated Cox5a was mainly present as a free subunit. We have found out that the major COX assembly subcomplexes accumulated due to SURF1 mutations range in size between approximately 85-140kDa. In addition to the originally proposed S2 intermediate they might also represent Cox1-containing complexes lacking other COX subunits. Unlike the assembled COX, subcomplexes are unable to associate with complexes I and III.
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Weraarpachai W, Sasarman F, Nishimura T, Antonicka H, Auré K, Rötig A, Lombès A, Shoubridge EA. Mutations in C12orf62, a factor that couples COX I synthesis with cytochrome c oxidase assembly, cause fatal neonatal lactic acidosis. Am J Hum Genet 2012; 90:142-51. [PMID: 22243966 DOI: 10.1016/j.ajhg.2011.11.027] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 11/09/2011] [Accepted: 11/28/2011] [Indexed: 11/16/2022] Open
Abstract
We investigated a family in which the index subject presented with severe congenital lactic acidosis and dysmorphic features associated with a cytochrome c oxidase (COX)-assembly defect and a specific decrease in the synthesis of COX I, the subunit that nucleates COX assembly. Using a combination of microcell-mediated chromosome transfer, homozygosity mapping, and transcript profiling, we mapped the gene defect to chromosome 12 and identified a homozygous missense mutation (c.88G>A) in C12orf62. C12orf62 was not detectable by immunoblot analysis in subject fibroblasts, and retroviral expression of the wild-type C12orf62 cDNA rescued the biochemical phenotype. Furthermore, siRNA-mediated knockdown of C12orf 62 recapitulated the biochemical defect in control cells and exacerbated it in subject cells. C12orf62 is apparently restricted to the vertebrate lineage. It codes for a very small (6 kDa), uncharacterized, single-transmembrane protein that localizes to mitochondria and elutes in a complex of ∼110 kDa by gel filtration. COX I, II, and IV coimmunoprecipated with an epitope-tagged version of C12orf62, and 2D blue-native-polyacrylamide-gel-electrophoresis analysis of newly synthesized mitochondrial COX subunits in subject fibroblasts showed that COX assembly was impaired and that the nascent enzyme complex was unstable. We conclude that C12orf62 is required for coordination of the early steps of COX assembly with the synthesis of COX I.
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Affiliation(s)
- Woranontee Weraarpachai
- Department of Human Genetics and Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
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Hannappel A, Bundschuh FA, Ludwig B. Role of Surf1 in heme recruitment for bacterial COX biogenesis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2011; 1817:928-37. [PMID: 21945856 DOI: 10.1016/j.bbabio.2011.09.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 09/04/2011] [Accepted: 09/12/2011] [Indexed: 12/12/2022]
Abstract
Biogenesis of the mitochondrial cytochrome c oxidase (COX) is a highly complex process involving subunits encoded both in the nuclear and the organellar genome; in addition, a large number of assembly factors participate in this process. The soil bacterium Paracoccus denitrificans is an interesting alternative model for the study of COX biogenesis events because the number of chaperones involved is restricted to an essential set acting in the metal centre formation of oxidase, and the high degree of sequence homology suggests the same basic mechanisms during early COX assembly. Over the last years, studies on the P. denitrificans Surf1 protein shed some light on this important assembly factor as a heme a binding protein associated with Leigh syndrome in humans. Here, we summarise our current knowledge about Surf1 and its role in heme a incorporation events during bacterial COX biogenesis. This article is part of a Special Issue entitled: Biogenesis/Assembly of Respiratory Enzyme Complexes.
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Affiliation(s)
- Achim Hannappel
- Institute of Biochemistry, Molecular Genetics Group, Goethe-University, Frankfurt am Main, Germany
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37
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Reinhold R, Bareth B, Balleininger M, Wissel M, Rehling P, Mick DU. Mimicking a SURF1 allele reveals uncoupling of cytochrome c oxidase assembly from translational regulation in yeast. Hum Mol Genet 2011; 20:2379-93. [PMID: 21470975 DOI: 10.1093/hmg/ddr145] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Defects in mitochondrial energy metabolism lead to severe human disorders, mainly affecting tissues especially dependent on oxidative phosphorylation, such as muscle and brain. Leigh Syndrome describes a severe encephalomyopathy in infancy, frequently caused by mutations in SURF1. SURF1, termed Shy1 in Saccharomyces cerevisiae, is a conserved assembly factor for the terminal enzyme of the respiratory chain, cytochrome c oxidase. Although the molecular function of SURF1/Shy1 is still enigmatic, loss of function leads to cytochrome c oxidase deficiency and reduced expression of the central subunit Cox1 in yeast. Here, we provide insights into the molecular mechanisms leading to disease through missense mutations in codons of the most conserved amino acids in SURF1. Mutations affecting G(124) do not compromise import of the SURF1 precursor protein but lead to fast turnover of the mature protein within the mitochondria. Interestingly, an Y(274)D exchange neither affects stability nor localization of the protein. Instead, SURF1(Y274D) accumulates in a 200 kDa cytochrome c oxidase assembly intermediate. Using yeast as a model, we demonstrate that the corresponding Shy1(Y344D) is able to overcome the stage where cytochrome c oxidase assembly links to the feedback regulation of mitochondrial Cox1 expression. However, Shy1(Y344D) impairs the assembly at later steps, most apparent at low temperature and exhibits a dominant-negative phenotype upon overexpression. Thus, exchanging the conserved tyrosine (Y(344)) with aspartate in yeast uncouples translational regulation of Cox1 from cytochrome c oxidase assembly and provides evidence for the dual functionality of Shy1.
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Affiliation(s)
- Robert Reinhold
- Abteilung für Biochemie II, Universität Göttingen, D-37073 Göttingen, Germany
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38
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Mkaouar-Rebai E, Ellouze E, Chamkha I, Kammoun F, Triki C, Fakhfakh F. Molecular-clinical correlation in a family with a novel heteroplasmic Leigh syndrome missense mutation in the mitochondrial cytochrome c oxidase III gene. J Child Neurol 2011; 26:12-20. [PMID: 20525945 DOI: 10.1177/0883073810371227] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cytochrome c oxidase is an essential component of the mitochondrial respiratory chain that catalyzes the reduction of molecular oxygen by reduced cytochrome c. In this study, the authors report the second mutation associated with Leigh syndrome in the blood and buccal mucosa of 2 affected members of a Tunisian family. It was a novel heteroplasmic missense mitochondrial mutation at nucleotide 9478 in the gene specifying subunit III of cytochrome c oxidase substituting the valine at position 91 to alanine in a highly conserved amino acid. It was found with a high mutant load in tissues derived from endoderm (buccal mucosa) and mesoderm (blood). However, it was nearly absent in tissue derived from ectoderm (hair follicles). It was absent in 120 healthy controls, and PolyPhen analysis showed that the hydropathy index changed from +1.276 to +0.242, and the number of structures of the 3D protein decreased from 39 to 32.
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Affiliation(s)
- Emna Mkaouar-Rebai
- Laboratoire de Génétique Moléculaire Humaine, Faculté de Médecine de Sfax, Tunisia.
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39
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A novel heme a insertion factor gene cotranscribes with the Thermus thermophilus cytochrome ba3 oxidase locus. J Bacteriol 2010; 192:4712-9. [PMID: 20622059 DOI: 10.1128/jb.00548-10] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Studying the biogenesis of the Thermus thermophilus cytochrome ba(3) oxidase, we analyze heme a cofactor insertion into this membrane protein complex. Only three proteins linked to oxidase maturation have been described for this extreme thermophile, and in particular, no evidence for a canonical Surf1 homologue, required for heme a insertion, is available from genome sequence data. Here, we characterize the product of an open reading frame, cbaX, in the operon encoding subunits of the ba(3)-type cytochrome c oxidase. CbaX shares no sequence identity with any known oxidase biogenesis factor, and CbaX homologues are found only in the Thermaceae group. In a series of cbaX deletion and complementation experiments, we demonstrate that the resulting ba(3) oxidase complexes, affinity purified via an internally inserted His tag located in subunit I, are severely affected in their enzymatic activities and heme compositions in both the low- and high-spin sites. Thus, CbaX displays typical features of a generic Surf1 factor essential for binding and positioning the heme a moiety for correct assembly into the protein scaffold of oxidase subunit I.
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40
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Sasarman F, Brunel-Guitton C, Antonicka H, Wai T, Shoubridge EA. LRPPRC and SLIRP interact in a ribonucleoprotein complex that regulates posttranscriptional gene expression in mitochondria. Mol Biol Cell 2010; 21:1315-23. [PMID: 20200222 PMCID: PMC2854090 DOI: 10.1091/mbc.e10-01-0047] [Citation(s) in RCA: 198] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Mutations in LRPPRC are responsible for the French Canadian variant of Leigh syndrome (LSFC), a neurodegenerative disorder caused by a tissue-specific deficiency in cytochrome c oxidase (COX). To investigate the pathogenic mechanism of disease, we studied LRPPRC function in LSFC and control fibroblasts. The level of mutated LRPPRC is reduced in LSFC cells, and this results in decreased steady-state levels of most mitochondrial mRNAs, but not rRNAs or tRNAs, a phenotype that can be reproduced by siRNA-mediated knockdown of LRPPRC in control cells. Processing of the primary transcripts appears normal. The resultant defect in mitochondrial protein synthesis in LSFC cells disproportionately affects the COX subunits, leading to an isolated COX assembly defect. Further knockdown of LRPPRC produces a generalized assembly defect in all oxidative phosphorylation complexes containing mtDNA-encoded subunits, due to a severe decrease in all mitochondrial mRNAs. LRPPRC exists in a high-molecular-weight complex, and it coimmunoprecipitates with SLIRP, a stem-loop RNA-binding protein. Although this interaction does not depend on mitochondrial mRNA, both proteins show reduced stability in its absence. These results implicate LRPPRC in posttranscriptional mitochondrial gene expression as part of a ribonucleoprotein complex that regulates the stability and handling of mature mRNAs.
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Affiliation(s)
- Florin Sasarman
- Department of Human Genetics, Montreal Neurological Institute, McGill University, Montreal, QC, H3A 2B4, Canada
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41
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Stiburek L, Zeman J. Assembly factors and ATP-dependent proteases in cytochrome c oxidase biogenesis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:1149-58. [PMID: 20398622 DOI: 10.1016/j.bbabio.2010.04.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Revised: 03/14/2010] [Accepted: 04/07/2010] [Indexed: 12/29/2022]
Abstract
Eukaryotic cytochrome c oxidase (CcO), the terminal enzyme of the energy-transducing mitochondrial electron transport chain is a hetero-oligomeric, heme-copper oxidase complex composed of both mitochondrially and nuclear-encoded subunits. It is embedded in the inner mitochondrial membrane where it couples the transfer of electrons from reduced cytochrome c to molecular oxygen with vectorial proton translocation across the membrane. The biogenesis of CcO is a complicated sequential process that requires numerous specific accessory proteins, so-called assembly factors, which include translational activators, translocases, molecular chaperones, copper metallochaperones and heme a biosynthetic enzymes. Besides these CcO-specific protein factors, the correct biogenesis of CcO requires an even greater number of proteins with much broader substrate specificities. Indeed, growing evidence indicates that mitochondrial ATP-dependent proteases might play an important role in CcO biogenesis. Out of the four identified energy-dependent mitochondrial proteases, three were shown to be directly involved in proteolysis of CcO subunits. In addition to their well-established protein-quality control function these oligomeric proteolytic complexes with chaperone-like activities may function as molecular chaperones promoting productive folding and assembly of subunit proteins. In this review, we summarize the current knowledge of the functional involvement of eukaryotic CcO-specific assembly factors and highlight the possible significance for CcO biogenesis of mitochondrial ATP-dependent proteases.
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Affiliation(s)
- Lukas Stiburek
- Charles University in Prague, First Faculty of Medicine, Department of Pediatrics, Prague, Czech Republic.
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42
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Piekutowska-Abramczuk D, Magner M, Popowska E, Pronicki M, Karczmarewicz E, Sykut-Cegielska J, Kmiec T, Jurkiewicz E, Szymanska-Debinska T, Bielecka L, Krajewska-Walasek M, Vesela K, Zeman J, Pronicka E. SURF1 missense mutations promote a mild Leigh phenotype. Clin Genet 2009; 76:195-204. [PMID: 19780766 DOI: 10.1111/j.1399-0004.2009.01195.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
UNLABELLED SURF1 gene mutations are the most common cause of Leigh syndrome (LS), a rare progressive neurodegenerative disorder of infancy, characterized by symmetric necrotizing lesions and hypervascularity in the brainstem and basal ganglia, leading to death before the age of 4 years. Most of the reported mutations create premature termination codons, whereas missense mutations are rare. The aim of the study was to characterize the natural history of LS patients carrying at least one missense mutation in the SURF1 gene. Nineteen such patients (8 own cases and 11 reported in the literature) were compared with a reference group of 20 own c.845_846delCT homozygous patients, and with other LS(SURF-) cases described in the literature. Disease onset in the studied group was delayed. Acute failure to thrive and hyperventilation episodes were rare, respiratory failure did not appear before the age of 4 years. Dystonia, motor regression and eye movement dissociation developed slowly. The number of patients who survived 7 years of life totaled 9 out of 15 (60%) in the 'missense group' and 1 out of 26 (4%) patients with mutations leading to truncated proteins. IN CONCLUSION (i) The presence of a missense mutation in the SURF1 gene may correlate with a milder course and longer survival of Leigh patients, (ii) normal magnetic resonance imaging (MRI) findings, normal blood lactate value, and only mild decrease of cytochrome c oxidase (COX) activity are not sufficient reasons to forego SURF1 mutation analysis in differential diagnosis.
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Bundschuh FA, Hannappel A, Anderka O, Ludwig B. Surf1, associated with Leigh syndrome in humans, is a heme-binding protein in bacterial oxidase biogenesis. J Biol Chem 2009; 284:25735-41. [PMID: 19625251 DOI: 10.1074/jbc.m109.040295] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Biogenesis of mitochondrial cytochrome c oxidase (COX) relies on a large number of assembly factors, among them the transmembrane protein Surf1. The loss of human Surf1 function is associated with Leigh syndrome, a fatal neurodegenerative disorder caused by severe COX deficiency. In the bacterium Paracoccus denitrificans, two homologous proteins, Surf1c and Surf1q, were identified, which we characterize in the present study. When coexpressed in Escherichia coli together with enzymes for heme a synthesis, the bacterial Surf1 proteins bind heme a in vivo. Using redox difference spectroscopy and isothermal titration calorimetry, the binding of the heme cofactor to purified apo-Surf1c and apo-Surf1q is quantified: Each of the Paracoccus proteins binds heme a in a 1:1 stoichiometry and with Kd values in the submicromolar range. In addition, we identify a conserved histidine as a residue crucial for heme binding. Contrary to most earlier concepts, these data support a direct role of Surf1 in heme a cofactor insertion into COX subunit I by providing a protein-bound heme a pool.
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Affiliation(s)
- Freya A Bundschuh
- Institute of Biochemistry, Molecular Genetics, Goethe University, D-60438 Frankfurt am Main, Germany
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44
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Weraarpachai W, Antonicka H, Sasarman F, Seeger J, Schrank B, Kolesar JE, Lochmüller H, Chevrette M, Kaufman BA, Horvath R, Shoubridge EA. Mutation in TACO1, encoding a translational activator of COX I, results in cytochrome c oxidase deficiency and late-onset Leigh syndrome. Nat Genet 2009; 41:833-7. [DOI: 10.1038/ng.390] [Citation(s) in RCA: 229] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Accepted: 04/27/2009] [Indexed: 12/15/2022]
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Expression of the Ciona intestinalis alternative oxidase (AOX) in Drosophila complements defects in mitochondrial oxidative phosphorylation. Cell Metab 2009; 9:449-60. [PMID: 19416715 DOI: 10.1016/j.cmet.2009.03.004] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Revised: 11/27/2008] [Accepted: 03/11/2009] [Indexed: 11/20/2022]
Abstract
Defects in mitochondrial OXPHOS are associated with diverse and mostly intractable human disorders. The single-subunit alternative oxidase (AOX) found in many eukaryotes, but not in arthropods or vertebrates, offers a potential bypass of the OXPHOS cytochrome chain under conditions of pathological OXPHOS inhibition. We have engineered Ciona intestinalis AOX for conditional expression in Drosophila melanogaster. Ubiquitous AOX expression produced no detrimental phenotype in wild-type flies. However, mitochondrial suspensions from AOX-expressing flies exhibited a significant cyanide-resistant substrate oxidation, and the flies were partially resistant to both cyanide and antimycin. AOX expression was able to complement the semilethality of partial knockdown of both cyclope (COXVIc) and the complex IV assembly factor Surf1. It also rescued the locomotor defect and excess mitochondrial ROS production of flies mutated in dj-1beta, a Drosophila homolog of the human Parkinson's disease gene DJ1. AOX appears to offer promise as a wide-spectrum therapeutic tool in OXPHOS disorders.
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Stiburek L, Vesela K, Hansikova H, Hulkova H, Zeman J. Loss of function of Sco1 and its interaction with cytochrome c oxidase. Am J Physiol Cell Physiol 2009; 296:C1218-26. [PMID: 19295170 DOI: 10.1152/ajpcell.00564.2008] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sco1 and Sco2 are mitochondrial copper-binding proteins involved in the biogenesis of the Cu(A) site in the cytochrome c oxidase (CcO) subunit Cox2 and in the maintenance of cellular copper homeostasis. Human Surf1 is a CcO assembly factor with an important but poorly characterized role in CcO biogenesis. Here, we analyzed the impact on CcO assembly and tissue copper levels of a G132S mutation in the juxtamembrane region of SCO1 metallochaperone associated with early onset hypertrophic cardiomyopathy, encephalopathy, hypotonia, and hepatopathy, assessed the total copper content of various SURF1 and SCO2-deficient tissues, and investigated the possible physical association between CcO and Sco1. The steady-state level of mutant Sco1 was severely decreased in the muscle mitochondria of the SCO1 patient, indicating compromised stability and thus loss of function of the protein. Unlike the wild-type variant, residual mutant Sco1 appeared to migrate exclusively in the monomeric form on blue native gels. Both the activity and content of CcO were reduced in the patient's muscle to approximately 10-20% of control values. SCO1-deficient mitochondria showed accumulation of two Cox2 subcomplexes, suggesting that Sco1 is very likely responsible for a different posttranslational aspect of Cox2 maturation than Sco2. Intriguingly, the various SURF1-deficient samples analyzed showed a tissue-specific copper deficiency similar to that of SCO-deficient samples, suggesting a role for Surf1 in copper homeostasis regulation. Finally, both blue native immunoblot analysis and coimmunoprecipitation revealed that a fraction of Sco1 physically associates with the CcO complex in human muscle mitochondria, suggesting a possible direct relationship between CcO and the regulation of cellular copper homeostasis.
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Piekutowska-Abramczuk D, Popowska E, Pronicki M, Karczmarewicz E, Tylek-Lemanska D, Sykut-Cegielska J, Szymanska-Dembinska T, Bielecka L, Krajewska-Walasek M, Pronicka E. High prevalence of SURF1 c.845_846delCT mutation in Polish Leigh patients. Eur J Paediatr Neurol 2009; 13:146-53. [PMID: 18583168 DOI: 10.1016/j.ejpn.2008.03.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2007] [Revised: 03/12/2008] [Accepted: 03/17/2008] [Indexed: 11/19/2022]
Abstract
Leigh syndrome is a neuropathological disorder with typical morphological changes in brain, appearing regardless of diverse molecular background. One of the most common enzymatic defects in Leigh patients is cytochrome c oxidase deficiency associated with recessive mutations in the SURF1 gene. To assess the SURF1 mutation profile among Polish patients we studied 41 affected children from 34 unrelated families by PCR-SSCP and sequencing. Four novel mutations, c.39delG, c.752-1G>C, c.800_801insT, c.821A>G, and five described pathogenic changes, c.311_312insAT312_321del10, c.688C>T, c.704T>C, c.756_757delCA, c.845_846delCT, were identified in 85.3% of analysed probands. One mutation, c.845_846delCT, was identified in 77.6% of SURF1 alleles. Up to now, it has been reported only in 9% of alleles in other parts of the world. The deletion was used as LS(SURF1-) marker in population studies. Eight heterozygous carriers of the mutation were found in a cohort of 2890 samples. The estimated c.845_846delCT allele frequency is 1:357 (0.28+/-0.2%), and the lowest predicted LS(SURF1-) frequency in Poland 1:126,736.births. Relatively high frequency of LS(SURF1-) in Poland with remarkable c.845_846delCT mutation dominance allows one to start the differential diagnosis of LS in each patient of Polish (and probably Slavonic) origin from the direct search for c.845_846delCT SURF1 mutation.
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Affiliation(s)
- Dorota Piekutowska-Abramczuk
- Department of Medical Genetics, Children's Memorial Health Institute, Al. Dzieci Polskich 20, 04-730 Warsaw, Poland.
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Bundschuh FA, Hoffmeier K, Ludwig B. Two variants of the assembly factor Surf1 target specific terminal oxidases in Paracoccus denitrificans. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2008; 1777:1336-43. [PMID: 18582433 DOI: 10.1016/j.bbabio.2008.05.448] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2008] [Revised: 05/26/2008] [Accepted: 05/27/2008] [Indexed: 02/06/2023]
Abstract
Biogenesis of cytochrome c oxidase (COX) relies on a large number of assembly proteins, one of them being Surf1. In humans, the loss of Surf1 function is associated with Leigh syndrome, a fatal neurodegenerative disorder. In the soil bacterium Paracoccus denitrificans, homologous genes specifying Surf1 have been identified and located in two operons of terminal oxidases: surf1q is the last gene of the qox operon (coding for a ba(3)-type ubiquinol oxidase), and surf1c is found at the end of the cta operon (encoding subunits of the aa(3)-type cytochrome c oxidase). We introduced chromosomal single and double deletions for both surf1 genes, leading to significantly reduced oxidase activities in membrane. Our experiments on P. denitrificans surf1 single deletion strains show that both Surf1c and Surf1q are functional and act independently for the aa(3)-type cytochrome c oxidase and the ba(3)-type quinol oxidase, respectively. This is the first direct experimental evidence for the involvement of a Surf1 protein in the assembly of a quinol oxidase. Analyzing the heme content of purified cytochrome c oxidase, we conclude that Surf1, though not indispensable for oxidase assembly, is involved in an early step of cofactor insertion into subunit I.
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Affiliation(s)
- Freya A Bundschuh
- Institut für Biochemie, Abteilung Molekulare Genetik, Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany.
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Baden KN, Murray J, Capaldi RA, Guillemin K. Early Developmental Pathology Due to Cytochrome c Oxidase Deficiency Is Revealed by a New Zebrafish Model. J Biol Chem 2007; 282:34839-49. [PMID: 17761683 DOI: 10.1074/jbc.m703528200] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Deficiency of cytochrome c oxidase (COX) is associated with significant pathology in humans. However, the consequences for organogenesis and early development are not well understood. We have investigated these issues using a zebrafish model. COX deficiency was induced using morpholinos to reduce expression of CoxVa, a structural subunit, and Surf1, an assembly factor, both of which impaired COX assembly. Reduction of COX activity to 50% resulted in developmental defects in endodermal tissue, cardiac function, and swimming behavior. Cellular investigations revealed different underlying mechanisms. Apoptosis was dramatically increased in the hindbrain and neural tube, and secondary motor neurons were absent or abnormal, explaining the motility defect. In contrast, the heart lacked apoptotic cells but showed increasingly poor performance over time, consistent with energy deficiency. The zebrafish model has revealed tissue-specific responses to COX deficiency and holds promise for discovery of new therapies to treat mitochondrial diseases in humans.
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Affiliation(s)
- Katrina N Baden
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon 97403-1229, USA
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Zee JM, Glerum DM. Defects in cytochrome oxidase assembly in humans: lessons from yeast. Biochem Cell Biol 2007; 84:859-69. [PMID: 17215873 DOI: 10.1139/o06-201] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The biogenesis of the inner mitochondrial membrane enzyme cytochrome c oxidase (COX) is a complex process that requires the actions of ancillary proteins, collectively called assembly factors. Studies with the yeast Saccharomyces cerevisiae have provided considerable insight into the COX assembly pathway and have proven to be a fruitful model for understanding the molecular bases for inherited COX deficiencies in humans. In this review, we focus on critical steps in the COX assembly pathway. These processes are conserved from yeast to humans and are known to be involved in the etiology of human COX deficiencies. The contributions from our studies in yeast suggest that this organism remains an excellent model system for delineating the molecular mechanisms underlying COX assembly defects in humans. Current progress suggests that a complete picture of COX assembly will be achieved in the near future.
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Affiliation(s)
- Jennifer M Zee
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 0M2, Canada
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