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Aguilar K, Jakubek P, Zorzano A, Wieckowski MR. Primary mitochondrial diseases: The intertwined pathophysiology of bioenergetic dysregulation, oxidative stress and neuroinflammation. Eur J Clin Invest 2024; 54:e14217. [PMID: 38644687 DOI: 10.1111/eci.14217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 04/02/2024] [Accepted: 04/03/2024] [Indexed: 04/23/2024]
Abstract
OBJECTIVES AND SCOPE Primary mitochondrial diseases (PMDs) are rare genetic disorders resulting from mutations in genes crucial for effective oxidative phosphorylation (OXPHOS) that can affect mitochondrial function. In this review, we examine the bioenergetic alterations and oxidative stress observed in cellular models of primary mitochondrial diseases (PMDs), shedding light on the intricate complexity between mitochondrial dysfunction and cellular pathology. We explore the diverse cellular models utilized to study PMDs, including patient-derived fibroblasts, induced pluripotent stem cells (iPSCs) and cybrids. Moreover, we also emphasize the connection between oxidative stress and neuroinflammation. INSIGHTS The central nervous system (CNS) is particularly vulnerable to mitochondrial dysfunction due to its dependence on aerobic metabolism and the correct functioning of OXPHOS. Similar to other neurodegenerative diseases affecting the CNS, individuals with PMDs exhibit several neuroinflammatory hallmarks alongside neurodegeneration, a pattern also extensively observed in mouse models of mitochondrial diseases. Based on histopathological analysis of postmortem human brain tissue and findings in mouse models of PMDs, we posit that neuroinflammation is not merely a consequence of neurodegeneration but a potential pathogenic mechanism for disease progression that deserves further investigation. This recognition may pave the way for novel therapeutic strategies for this group of devastating diseases that currently lack effective treatments. SUMMARY In summary, this review provides a comprehensive overview of bioenergetic alterations and redox imbalance in cellular models of PMDs while underscoring the significance of neuroinflammation as a potential driver in disease progression.
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Affiliation(s)
- Kevin Aguilar
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona, Spain
| | - Patrycja Jakubek
- Laboratory of Mitochondrial Biology and Metabolism, Nencki Institute of Experimental Biology PAS, Warsaw, Poland
| | - Antonio Zorzano
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona, Spain
- Departament de Bioquímica i Biomedicina Molecular, Universitat de Barcelona, Barcelona, Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
| | - Mariusz R Wieckowski
- Laboratory of Mitochondrial Biology and Metabolism, Nencki Institute of Experimental Biology PAS, Warsaw, Poland
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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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Fan T, Guan P, Zhong X, Xiang M, Peng Y, Zhou R, Gong J, Zheng Y, Dai A, Feng J, Yu H, Li J, Li H, Wang Y. Functional Connectivity Alterations and Molecular Characterization of the Anterior Cingulate Cortex in Tinnitus Pathology without Hearing Loss. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2304709. [PMID: 38009798 PMCID: PMC10797451 DOI: 10.1002/advs.202304709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 11/06/2023] [Indexed: 11/29/2023]
Abstract
Compared with individuals with hearing loss, tinnitus patients without hearing loss have more psychological or emotional problems. Tinnitus is closely associated to abnormal metabolism and function of the limbic system, a key brain region for emotion experience, but the underlying molecular mechanism remains unknown. Using whole-brain microvasculature dynamics imaging, the anterior cingulate cortex (ACC) is identified as a key brain region of limbic system involve in the onset of salicylate-induced tinnitus in mice. In the tinnitus group, there is enhanced purine metabolism, oxidative phosphorylation, and a distinct pattern of phosphorylation in glutamatergic synaptic pathway according to the metabolome profiles, quantitative proteomic, and phosphoproteomic data of mice ACC tissue. Electroencephalogram in tinnitus patients with normal hearing thresholds show that the functional connectivity between pregenual anterior cingulate cortex and the primary auditory cortex is significantly increased for high-gamma frequency band, which is positively correlated with the serum glutamate level. These findings indicate that ACC plays an important role in the pathophysiology of tinnitus by interacting with the primary auditory cortex and provide potential molecular targets in the ACC for tinnitus treatment.
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Affiliation(s)
- Ting Fan
- ENT Institute and Department of OtorhinolaryngologyEYE & ENT HospitalFudan UniversityShanghai200031China
- NHC Key Laboratory of Hearing MedicineFudan UniversityShanghai200031China
| | - Peng‐Fei Guan
- ENT Institute and Department of OtorhinolaryngologyEYE & ENT HospitalFudan UniversityShanghai200031China
- NHC Key Laboratory of Hearing MedicineFudan UniversityShanghai200031China
| | - Xiao‐Fang Zhong
- Clinical Laboratory CenterChildren's Hospital of Fudan UniversityShanghai201102China
| | - Meng‐Ya Xiang
- ENT Institute and Department of OtorhinolaryngologyEYE & ENT HospitalFudan UniversityShanghai200031China
- NHC Key Laboratory of Hearing MedicineFudan UniversityShanghai200031China
| | - Ying‐Qiu Peng
- ENT Institute and Department of OtorhinolaryngologyEYE & ENT HospitalFudan UniversityShanghai200031China
- NHC Key Laboratory of Hearing MedicineFudan UniversityShanghai200031China
| | - Ruo‐Qiao Zhou
- ENT Institute and Department of OtorhinolaryngologyEYE & ENT HospitalFudan UniversityShanghai200031China
- NHC Key Laboratory of Hearing MedicineFudan UniversityShanghai200031China
| | - Jia‐Min Gong
- ENT Institute and Department of OtorhinolaryngologyEYE & ENT HospitalFudan UniversityShanghai200031China
| | - Yu‐Qing Zheng
- Zhejiang Chinese Medical UniversityHangzhouZhejiang310053China
| | - A‐Qiang Dai
- ENT Institute and Department of OtorhinolaryngologyEYE & ENT HospitalFudan UniversityShanghai200031China
| | - Jia‐Ling Feng
- ENT Institute and Department of OtorhinolaryngologyEYE & ENT HospitalFudan UniversityShanghai200031China
| | - Hong‐Zhe Yu
- ENT Institute and Department of OtorhinolaryngologyEYE & ENT HospitalFudan UniversityShanghai200031China
- NHC Key Laboratory of Hearing MedicineFudan UniversityShanghai200031China
| | - Jian Li
- Clinical Laboratory CenterChildren's Hospital of Fudan UniversityShanghai201102China
| | - Hua‐Wei Li
- ENT Institute and Department of OtorhinolaryngologyEYE & ENT HospitalFudan UniversityShanghai200031China
- NHC Key Laboratory of Hearing MedicineFudan UniversityShanghai200031China
| | - Yun‐Feng Wang
- ENT Institute and Department of OtorhinolaryngologyEYE & ENT HospitalFudan UniversityShanghai200031China
- NHC Key Laboratory of Hearing MedicineFudan UniversityShanghai200031China
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Anderson AJ, Crameri JJ, Ang C, Malcolm TR, Kang Y, Baker MJ, Palmer CS, Sharpe AJ, Formosa LE, Ganio K, Baker MJ, McDevitt CA, Ryan MT, Maher MJ, Stojanovski D. Human Tim8a, Tim8b and Tim13 are auxiliary assembly factors of mature Complex IV. EMBO Rep 2023; 24:e56430. [PMID: 37272231 PMCID: PMC10398661 DOI: 10.15252/embr.202256430] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 05/11/2023] [Accepted: 05/16/2023] [Indexed: 06/06/2023] Open
Abstract
Human Tim8a and Tim8b are paralogous intermembrane space proteins of the small TIM chaperone family. Yeast small TIMs function in the trafficking of proteins to the outer and inner mitochondrial membranes. This putative import function for hTim8a and hTim8b has been challenged in human models, but their precise molecular function(s) remains undefined. Likewise, the necessity for human cells to encode two Tim8 proteins and whether any potential redundancy exists is unclear. We demonstrate that hTim8a and hTim8b function in the assembly of cytochrome c oxidase (Complex IV). Using affinity enrichment mass spectrometry, we define the interaction network of hTim8a, hTim8b and hTim13, identifying subunits and assembly factors of the Complex IV COX2 module. hTim8-deficient cells have a COX2 and COX3 module defect and exhibit an accumulation of the Complex IV S2 subcomplex. These data suggest that hTim8a and hTim8b function in assembly of Complex IV via interactions with intermediate-assembly subcomplexes. We propose that hTim8-hTim13 complexes are auxiliary assembly factors involved in the formation of the Complex IV S3 subcomplex during assembly of mature Complex IV.
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Affiliation(s)
- Alexander J Anderson
- Department of Biochemistry and PharmacologyThe University of MelbourneParkvilleVicAustralia
- The Bio21 Molecular Science and Biotechnology InstituteThe University of MelbourneParkvilleVicAustralia
| | - Jordan J Crameri
- Department of Biochemistry and PharmacologyThe University of MelbourneParkvilleVicAustralia
- The Bio21 Molecular Science and Biotechnology InstituteThe University of MelbourneParkvilleVicAustralia
| | - Ching‐Seng Ang
- The Bio21 Molecular Science and Biotechnology InstituteThe University of MelbourneParkvilleVicAustralia
| | - Tess R Malcolm
- The Bio21 Molecular Science and Biotechnology InstituteThe University of MelbourneParkvilleVicAustralia
- School of ChemistryThe University of MelbourneParkvilleVicAustralia
| | - Yilin Kang
- Department of Biochemistry and PharmacologyThe University of MelbourneParkvilleVicAustralia
- The Bio21 Molecular Science and Biotechnology InstituteThe University of MelbourneParkvilleVicAustralia
| | - Megan J Baker
- Department of Biochemistry and PharmacologyThe University of MelbourneParkvilleVicAustralia
- The Bio21 Molecular Science and Biotechnology InstituteThe University of MelbourneParkvilleVicAustralia
| | - Catherine S Palmer
- Department of Biochemistry and PharmacologyThe University of MelbourneParkvilleVicAustralia
- The Bio21 Molecular Science and Biotechnology InstituteThe University of MelbourneParkvilleVicAustralia
| | - Alice J Sharpe
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery InstituteMonash UniversityClaytonVicAustralia
| | - Luke E Formosa
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery InstituteMonash UniversityClaytonVicAustralia
| | - Katherine Ganio
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and ImmunityThe University of MelbourneParkvilleVicAustralia
| | - Michael J Baker
- Department of Biochemistry and PharmacologyThe University of MelbourneParkvilleVicAustralia
- The Bio21 Molecular Science and Biotechnology InstituteThe University of MelbourneParkvilleVicAustralia
| | - Christopher A McDevitt
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and ImmunityThe University of MelbourneParkvilleVicAustralia
| | - Michael T Ryan
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery InstituteMonash UniversityClaytonVicAustralia
| | - Megan J Maher
- The Bio21 Molecular Science and Biotechnology InstituteThe University of MelbourneParkvilleVicAustralia
- School of ChemistryThe University of MelbourneParkvilleVicAustralia
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular ScienceLa Trobe UniversityBundooraVicAustralia
| | - Diana Stojanovski
- Department of Biochemistry and PharmacologyThe University of MelbourneParkvilleVicAustralia
- The Bio21 Molecular Science and Biotechnology InstituteThe University of MelbourneParkvilleVicAustralia
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Yan C, Zhang ZY, Lv Y, Wang Z, Jiang K, Li JT. Genome of Laudakia sacra Provides New Insights into High-Altitude Adaptation of Ectotherms. Int J Mol Sci 2022; 23:ijms231710081. [PMID: 36077479 PMCID: PMC9456099 DOI: 10.3390/ijms231710081] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 08/29/2022] [Accepted: 08/31/2022] [Indexed: 12/02/2022] Open
Abstract
Anan’s rock agama (Laudakia sacra) is a lizard species endemic to the harsh high-altitude environment of the Qinghai–Tibet Plateau, a region characterized by low oxygen tension and high ultraviolet (UV) radiation. To better understand the genetic mechanisms underlying highland adaptation of ectotherms, we assembled a 1.80-Gb L. sacra genome, which contained 284 contigs with an N50 of 20.19 Mb and a BUSCO score of 93.54%. Comparative genomic analysis indicated that mutations in certain genes, including HIF1A, TIE2, and NFAT family members and genes in the respiratory chain, may be common adaptations to hypoxia among high-altitude animals. Compared with lowland reptiles, MLIP showed a convergent mutation in L. sacra and the Tibetan hot-spring snake (Thermophis baileyi), which may affect their hypoxia adaptation. In L. sacra, several genes related to cardiovascular remodeling, erythropoiesis, oxidative phosphorylation, and DNA repair may also be tailored for adaptation to UV radiation and hypoxia. Of note, ERCC6 and MSH2, two genes associated with adaptation to UV radiation in T. baileyi, exhibited L. sacra-specific mutations that may affect peptide function. Thus, this study provides new insights into the potential mechanisms underpinning high-altitude adaptation in ectotherms and reveals certain genetic generalities for animals’ survival on the plateau.
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Affiliation(s)
- Chaochao Yan
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
| | - Zhi-Yi Zhang
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
- Correspondence: (Z.-Y.Z.); (J.-T.L.)
| | - Yunyun Lv
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
- College of Life Science, Neijiang Normal University, Neijiang 641100, China
| | - Zeng Wang
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
- University of Chinese Academy of Sciences, Beijing 101408, China
| | - Ke Jiang
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
| | - Jia-Tang Li
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
- University of Chinese Academy of Sciences, Beijing 101408, China
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming 650223, China
- Mangkang Biodiversity and Ecological Station, Tibet Ecological Safety Monitor Network, Changdu 854500, China
- Correspondence: (Z.-Y.Z.); (J.-T.L.)
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Nývltová E, Dietz JV, Seravalli J, Khalimonchuk O, Barrientos A. 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] [MESH Headings] [Grants] [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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Affiliation(s)
- Eva Nývltová
- Department of Neurology, University of Miami Miller School of Medicine, 1420NW 9th Ave, Miami, FL, 33136, USA
| | - Jonathan V Dietz
- Department of Biochemistry, University of Nebraska-Lincoln, 1901 Vine St. Beadle Center, Lincoln, NE, 68588, USA
| | - Javier Seravalli
- Nebraska Redox Biology Center, University of Nebraska-Lincoln, 1901 Vine St. Beadle Center, Lincoln, NE, 68588, USA
| | - Oleh Khalimonchuk
- Department of Biochemistry, University of Nebraska-Lincoln, 1901 Vine St. Beadle Center, Lincoln, NE, 68588, USA
- Nebraska Redox Biology Center, University of Nebraska-Lincoln, 1901 Vine St. Beadle Center, Lincoln, NE, 68588, USA
| | - Antoni Barrientos
- Department of Neurology, University of Miami Miller School of Medicine, 1420NW 9th Ave, Miami, FL, 33136, USA.
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, 1420NW 9th Ave, Miami, FL, 33136, USA.
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Molecular Signatures of Mitochondrial Complexes Involved in Alzheimer’s Disease via Oxidative Phosphorylation and Retrograde Endocannabinoid Signaling Pathways. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:9565545. [PMID: 35432724 PMCID: PMC9006080 DOI: 10.1155/2022/9565545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 03/22/2022] [Indexed: 11/17/2022]
Abstract
Objective The inability to intervene in Alzheimer's disease (AD) forces the search for promising gene-targeted therapies. This study was aimed at exploring molecular signatures and mechanistic pathways to improve the diagnosis and treatment of AD. Methods Microarray datasets were collected to filter differentially expressed genes (DEGs) between AD and nondementia controls. Weight gene correlation network analysis (WGCNA) was employed to analyze the correlation of coexpression modules with AD phenotype. A global regulatory network was established and then visualized using Cytoscape software to determine hub genes and their mechanistic pathways. Receiver operating characteristic (ROC) analysis was conducted to estimate the diagnostic performance of hub genes in AD prediction. Results A total of 2,163 DEGs from 13,049 background genes were screened in AD relative to nondementia controls. Among the six coexpression modules constructed by WGCNA, DEGs of the key modules with the strongest correlation with AD were extracted to build a global regulatory network. According to the Maximal Clique Centrality (MCC) method, five hub genes associated with mitochondrial complexes were chosen. Further pathway enrichment analysis of hub genes, such as oxidative phosphorylation and retrograde endocannabinoid signaling, was identified. According to the area under the curve (AUC) of about 70%, each hub gene exhibited a good diagnostic performance in predicting AD. Conclusions Our findings highlight the perturbation of mitochondrial complexes underlying AD onset, which is mediated by molecular signatures involved in oxidative phosphorylation (COX5A, NDUFAB1, SDHB, UQCRC2, and UQCRFS1) and retrograde endocannabinoid signaling (NDUFAB1) pathways.
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Yang G, Zhao T, Lu S, Weng J, Zeng X. T1121G Point Mutation in the Mitochondrial Gene COX1 Suppresses a Null Mutation in ATP23 Required for the Assembly of Yeast Mitochondrial ATP Synthase. Int J Mol Sci 2022; 23:ijms23042327. [PMID: 35216443 PMCID: PMC8877559 DOI: 10.3390/ijms23042327] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/10/2022] [Accepted: 02/16/2022] [Indexed: 02/04/2023] Open
Abstract
Nuclear-encoded Atp23 was previously shown to have dual functions, including processing the yeast Atp6 precursor and assisting the assembly of yeast mitochondrial ATP synthase. However, it remains unknown whether there are genes functionally complementary to ATP23 to rescue atp23 null mutant. In the present paper, we screen and characterize three revertants of atp23 null mutant and reveal a T1121G point mutation in the mitochondrial gene COX1 coding sequence, which leads to Val374Gly mutation in Cox1, the suppressor in the revertants. This was verified further by the partial restoration of mitochondrial ATP synthase assembly in atp23 null mutant transformed with exogenous hybrid COX1 T1121G mutant plasmid. The predicted tertiary structure of the Cox1 p.Val374Gly mutation showed no obvious difference from wild-type Cox1. By further chase labeling with isotope [35S]-methionine, we found that the stability of Atp6 of ATP synthase increased in the revertants compared with the atp23 null mutant. Taking all the data together, we revealed that the T1121G point mutation of mitochondrial gene COX1 could partially restore the unassembly of mitochondrial ATP synthase in atp23 null mutant by increasing the stability of Atp6. Therefore, this study uncovers a gene that is partially functionally complementary to ATP23 to rescue ATP23 deficiency, broadening our understanding of the relationship between yeast the cytochrome c oxidase complex and mitochondrial ATP synthase complex.
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Lebok P, Schütt K, Kluth M, Witzel I, Wölber L, Paluchowski P, Terracciano L, Wilke C, Heilenkötter U, Müller V, Schmalfeldt B, Simon R, Sauter G, Von Leffern I, Krech T, Krech RH, Jacobsen F, Burandt E. High mitochondrial content is associated with breast cancer aggressiveness. Mol Clin Oncol 2021; 15:203. [PMID: 34462659 PMCID: PMC8375016 DOI: 10.3892/mco.2021.2365] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 06/23/2021] [Indexed: 12/16/2022] Open
Abstract
Mitochondria are relevant for cancer initiation and progression. Antibodies against mitochondrially encoded cytochrome c oxidase II (MTCO2), targeting a mitochondria specific epitope, can be used to quantitate the mitochondria content of tumor cells. The present study evaluated the impact of the cellular mitochondrial content on the prognosis of patients with breast cancer using immunohistochemical analysis on 2,197 arrayed breast cancer specimens. Results were compared with histological tumor parameters, patient overall survival, tumor cell proliferation using Ki67 labeling index (Ki67LI) and various other molecular features. Tumor cells exhibited stronger MTCO2 expression than normal breast epithelial cells. MTCO2 immunostaining was largely absent in normal breast epithelium, but was observed in 71.9% of 1,797 analyzable cancer specimens, including 34.6% tumors with weak expression, 22.3% with moderate expression and 15.0% with strong expression. High MTCO2 expression was significantly associated with advanced tumor stage, high Bloom-Richardson-Elston/Nottingham (BRE) grade, nodal metastasis and shorter overall survival (P<0.0001 each). In multivariate analysis, MTCO2 expression did not provide prognostic information independent of BRE grade, pathological tumor and pathological lymph node status. Additionally, significant associations were observed for high MTCO2 expression and various molecular features, including high Ki67LI, amplifications of HER2, MYC, CCND1 and MDM2, deletions of PTEN, 8p21 and 9p, low estrogen receptor expression (P<0.0001 each) and progesterone receptor expression (P<0.0001). The present study demonstrated that high MTCO2 expression was strongly associated with a poor prognosis and unfavorable phenotypical and molecular tumor features in patients with breast cancer. This suggests that the mitochondrial content may have a pivotal role in breast cancer progression.
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Affiliation(s)
- Patrick Lebok
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, D-20246 Hamburg, Germany
| | - Katharina Schütt
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, D-20246 Hamburg, Germany
| | - Martina Kluth
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, D-20246 Hamburg, Germany
| | - Isabell Witzel
- Department of Gynecology, University Medical Center Hamburg-Eppendorf, D-20246 Hamburg, Germany
| | - Linn Wölber
- Department of Gynecology, University Medical Center Hamburg-Eppendorf, D-20246 Hamburg, Germany
| | - Peter Paluchowski
- Department of Gynecology, Regio Clinic Pinneberg, D-25421 Pinneberg, Germany
| | - Luigi Terracciano
- Department of Pathology, Basel University Clinics, 4031 Basel, Switzerland
| | - Christian Wilke
- Department of Gynecology, Regio Clinic Elmshorn, D-25337 Elmshorn, Germany
| | - Uwe Heilenkötter
- Department of Gynecology, Clinical Centre Itzehoe, D-25524 Itzehoe, Germany
| | - Volkmar Müller
- Department of Gynecology, University Medical Center Hamburg-Eppendorf, D-20246 Hamburg, Germany
| | - Barbara Schmalfeldt
- Department of Gynecology, University Medical Center Hamburg-Eppendorf, D-20246 Hamburg, Germany
| | - Ronald Simon
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, D-20246 Hamburg, Germany
| | - Guido Sauter
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, D-20246 Hamburg, Germany
| | - Ingo Von Leffern
- Department of Gynecology, Albertinen Clinic Schnelsen, D-22457 Hamburg, Germany
| | - Till Krech
- Institute of Pathology, Clinical Centre Osnabrück, D-49076 Osnabrück, Germany
| | - Rainer Horst Krech
- Institute of Pathology, Clinical Centre Osnabrück, D-49076 Osnabrück, Germany
| | - Frank Jacobsen
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, D-20246 Hamburg, Germany
| | - Eike Burandt
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, D-20246 Hamburg, Germany
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Gladyck S, Aras S, Hüttemann M, Grossman LI. Regulation of COX Assembly and Function by Twin CX 9C Proteins-Implications for Human Disease. Cells 2021; 10:197. [PMID: 33498264 PMCID: PMC7909247 DOI: 10.3390/cells10020197] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/11/2021] [Accepted: 01/12/2021] [Indexed: 12/29/2022] Open
Abstract
Oxidative phosphorylation is a tightly regulated process in mammals that takes place in and across the inner mitochondrial membrane and consists of the electron transport chain and ATP synthase. Complex IV, or cytochrome c oxidase (COX), is the terminal enzyme of the electron transport chain, responsible for accepting electrons from cytochrome c, pumping protons to contribute to the gradient utilized by ATP synthase to produce ATP, and reducing oxygen to water. As such, COX is tightly regulated through numerous mechanisms including protein-protein interactions. The twin CX9C family of proteins has recently been shown to be involved in COX regulation by assisting with complex assembly, biogenesis, and activity. The twin CX9C motif allows for the import of these proteins into the intermembrane space of the mitochondria using the redox import machinery of Mia40/CHCHD4. Studies have shown that knockdown of the proteins discussed in this review results in decreased or completely deficient aerobic respiration in experimental models ranging from yeast to human cells, as the proteins are conserved across species. This article highlights and discusses the importance of COX regulation by twin CX9C proteins in the mitochondria via COX assembly and control of its activity through protein-protein interactions, which is further modulated by cell signaling pathways. Interestingly, select members of the CX9C protein family, including MNRR1 and CHCHD10, show a novel feature in that they not only localize to the mitochondria but also to the nucleus, where they mediate oxygen- and stress-induced transcriptional regulation, opening a new view of mitochondrial-nuclear crosstalk and its involvement in human disease.
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Affiliation(s)
- Stephanie Gladyck
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA; (S.G.); (S.A.); (M.H.)
| | - Siddhesh Aras
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA; (S.G.); (S.A.); (M.H.)
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services, Bethesda, Maryland and Detroit, MI 48201, USA
| | - Maik Hüttemann
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA; (S.G.); (S.A.); (M.H.)
| | - Lawrence I. Grossman
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA; (S.G.); (S.A.); (M.H.)
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services, Bethesda, Maryland and Detroit, MI 48201, USA
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11
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Čunátová K, Reguera DP, Houštěk J, Mráček T, Pecina P. Role of cytochrome c oxidase nuclear-encoded subunits in health and disease. Physiol Res 2020; 69:947-965. [PMID: 33129245 DOI: 10.33549/physiolres.934446] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Cytochrome c oxidase (COX), the terminal enzyme of mitochondrial electron transport chain, couples electron transport to oxygen with generation of proton gradient indispensable for the production of vast majority of ATP molecules in mammalian cells. The review summarizes current knowledge of COX structure and function of nuclear-encoded COX subunits, which may modulate enzyme activity according to various conditions. Moreover, some nuclear-encoded subunits posess tissue-specific and development-specific isoforms, possibly enabling fine-tuning of COX function in individual tissues. The importance of nuclear-encoded subunits is emphasized by recently discovered pathogenic mutations in patients with severe mitopathies. In addition, proteins substoichiometrically associated with COX were found to contribute to COX activity regulation and stabilization of the respiratory supercomplexes. Based on the summarized data, a model of three levels of quaternary COX structure is postulated. Individual structural levels correspond to subunits of the i) catalytic center, ii) nuclear-encoded stoichiometric subunits and iii) associated proteins, which may constitute several forms of COX with varying composition and differentially regulated function.
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Affiliation(s)
- K Čunátová
- Department of Bioenergetics, Institute of Physiology CAS, Prague, Czech Republic. ,
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12
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miR-204/COX5A axis contributes to invasion and chemotherapy resistance in estrogen receptor-positive breast cancers. Cancer Lett 2020; 492:185-196. [PMID: 32758616 DOI: 10.1016/j.canlet.2020.07.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 07/19/2020] [Accepted: 07/24/2020] [Indexed: 12/15/2022]
Abstract
Breast cancer is the most common cancer among women worldwide, with 70% being estrogen receptor-positive (ER+). Although ER-targeted treatment is effective in treating ER + breast cancer, chemoresistance and metastasis still prevail. Outcome-predictable biomarkers can help improve patient prognosis. Through the analysis of the Array Express database, The Cancer Genome Atlas-Breast Cancer datasets, and breast tumor tissue array results, we found that cytochrome c oxidase subunit 5a (COX5A) was related to poor prognosis of ER + breast cancer. Further studies revealed that COX5A was positively associated with metastasis and chemoresistance in ER + breast cancer. In vitro experiments showed that knockdown of COX5A was accompanied by a decrease in ERα expression, cell cycle arrest, and epithelial-mesenchymal transition blockade, resulting in an inhibition of proliferation and invasion. Knockdown of COX5A enhanced the chemosensitivity of breast cancer cells by decreasing adenosine triphosphate and increasing reactive oxygen species levels. We report that miR-204 can target and inhibit the expression of COX5A, thus, reversing the functions of COX5A in ER + breast cancer cells. We found that COX5A may serve as a prognostic biomarker in ER + breast cancer.
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Lobo‐Jarne T, Pérez‐Pérez R, Fontanesi F, Timón‐Gómez A, Wittig I, Peñas A, Serrano‐Lorenzo P, García‐Consuegra I, Arenas J, Martín MA, Barrientos A, Ugalde C. Multiple pathways coordinate assembly of human mitochondrial complex IV and stabilization of respiratory supercomplexes. EMBO J 2020; 39:e103912. [PMID: 32511785 PMCID: PMC7360963 DOI: 10.15252/embj.2019103912] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 04/20/2020] [Accepted: 05/06/2020] [Indexed: 12/28/2022] Open
Abstract
Mitochondrial respiratory chain complexes I, III, and IV can associate into larger structures termed supercomplexes or respirasomes, thereby generating structural interdependences among the individual complexes yet to be understood. In patients, nonsense mutations in complex IV subunit genes cause severe encephalomyopathies randomly associated with pleiotropic complex I defects. Using complexome profiling and biochemical analyses, we have explored the structural rearrangements of the respiratory chain in human cell lines depleted of the catalytic complex IV subunit COX1 or COX2. In the absence of a functional complex IV holoenzyme, several supercomplex I+III2 species coexist, which differ in their content of COX subunits and COX7A2L/HIGD2A assembly factors. The incorporation of an atypical COX1-HIGD2A submodule attenuates supercomplex I+III2 turnover rate, indicating an unexpected molecular adaptation for supercomplexes stabilization that relies on the presence of COX1 independently of holo-complex IV formation. Our data set the basis for complex I structural dependence on complex IV, revealing the co-existence of alternative pathways for the biogenesis of "supercomplex-associated" versus individual complex IV, which could determine physiological adaptations under different stress and disease scenarios.
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Affiliation(s)
| | | | - Flavia Fontanesi
- Department of BiochemistryUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Alba Timón‐Gómez
- Department of NeurologyUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Ilka Wittig
- SFB 815 Core UnitFunctional ProteomicsGoethe‐UniversitätFrankfurt am MainGermany
| | - Ana Peñas
- Instituto de Investigación Hospital 12 de Octubre (i+12)MadridSpain
| | | | - Inés García‐Consuegra
- Instituto de Investigación Hospital 12 de Octubre (i+12)MadridSpain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), U723MadridSpain
| | - Joaquín Arenas
- Instituto de Investigación Hospital 12 de Octubre (i+12)MadridSpain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), U723MadridSpain
| | - Miguel A Martín
- Instituto de Investigación Hospital 12 de Octubre (i+12)MadridSpain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), U723MadridSpain
| | - Antoni Barrientos
- Department of BiochemistryUniversity of Miami Miller School of MedicineMiamiFLUSA
- Department of NeurologyUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Cristina Ugalde
- Instituto de Investigación Hospital 12 de Octubre (i+12)MadridSpain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), U723MadridSpain
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14
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Chang R, Hsu CF, Tsai WB. Fabrication of Chlorophyll-Incorporated Nanogels for Potential Applications in Photothermal Cancer Therapy. ACS OMEGA 2018; 3:16057-16062. [PMID: 30556024 PMCID: PMC6288803 DOI: 10.1021/acsomega.8b01689] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 11/16/2018] [Indexed: 06/09/2023]
Abstract
Nanogels have been widely used in biomedical applications, such as carriers for hyperthermia cancer treatment, drug delivery, and imaging. Owing to the enhanced permeability and retention effect, nanogels have shown a great potential in cancer therapy. In this study, sodium copper chlorophyllin (SCC), a low cytotoxicity and biodegradable photothermal agent, was copolymerized with a nanogel of N-[3-(dimethylamino)propyl]methacrylamide. The nanogels could produce heat under exposure to a green laser with a 532 nm wavelength. The positively charged nature of the nanogels enhanced the endocytosis of the nanogels. The cell mortality was greatly enhanced with the treatment of the SCC-containing nanogels and green light illumination. Our results suggest the potential of SCC-containing nanogels in photothermal cancer therapy.
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Affiliation(s)
- Ray Chang
- Department of Chemical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 106, Taiwan
| | - Chin-Feng Hsu
- Department of Chemical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 106, Taiwan
| | - Wei-Bor Tsai
- Department of Chemical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 106, Taiwan
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Télot L, Rousseau E, Lesuisse E, Garcia C, Morlet B, Léger T, Camadro JM, Serre V. Quantitative proteomics in Friedreich's ataxia B-lymphocytes: A valuable approach to decipher the biochemical events responsible for pathogenesis. Biochim Biophys Acta Mol Basis Dis 2018; 1864:997-1009. [DOI: 10.1016/j.bbadis.2018.01.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 12/19/2017] [Accepted: 01/08/2018] [Indexed: 11/29/2022]
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Timón-Gómez A, Nývltová E, Abriata LA, Vila AJ, Hosler J, Barrientos A. Mitochondrial cytochrome c oxidase biogenesis: Recent developments. Semin Cell Dev Biol 2017; 76:163-178. [PMID: 28870773 DOI: 10.1016/j.semcdb.2017.08.055] [Citation(s) in RCA: 217] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 08/18/2017] [Accepted: 08/25/2017] [Indexed: 12/21/2022]
Abstract
Mitochondrial cytochrome c oxidase (COX) is the primary site of cellular oxygen consumption and is essential for aerobic energy generation in the form of ATP. Human COX is a copper-heme A hetero-multimeric complex formed by 3 catalytic core subunits encoded in the mitochondrial DNA and 11 subunits encoded in the nuclear genome. Investigations over the last 50 years have progressively shed light into the sophistication surrounding COX biogenesis and the regulation of this process, disclosing multiple assembly factors, several redox-regulated processes leading to metal co-factor insertion, regulatory mechanisms to couple synthesis of COX subunits to COX assembly, and the incorporation of COX into respiratory supercomplexes. Here, we will critically summarize recent progress and controversies in several key aspects of COX biogenesis: linear versus modular assembly, the coupling of mitochondrial translation to COX assembly and COX assembly into respiratory supercomplexes.
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Affiliation(s)
- Alba Timón-Gómez
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Eva Nývltová
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Luciano A Abriata
- Laboratory for Biomolecular Modeling & Protein Purification and Structure Facility, École Polytechnique Fédérale de Lausanne and Swiss Institute of Bioinformatics, Switzerland
| | - Alejandro J Vila
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR), Ocampo y Esmeralda, S2002LRK Rosario, Argentina
| | - Jonathan Hosler
- Department of Biochemistry, The University of Mississippi Medical Center, Jackson, MS, United States
| | - Antoni Barrientos
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, United States; Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, United States.
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17
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Martos-Sitcha JA, Bermejo-Nogales A, Calduch-Giner JA, Pérez-Sánchez J. Gene expression profiling of whole blood cells supports a more efficient mitochondrial respiration in hypoxia-challenged gilthead sea bream ( Sparus aurata). Front Zool 2017; 14:34. [PMID: 28694839 PMCID: PMC5501551 DOI: 10.1186/s12983-017-0220-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 06/28/2017] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Acclimation to abiotic challenges, including decreases in O2 availability, requires physiological and anatomical phenotyping to accommodate the organism to the environmental conditions. The retention of a nucleus and functional mitochondria in mature fish red blood cells makes blood a promising tissue to analyse the transcriptome and metabolic responses of hypoxia-challenged fish in an integrative and non-invasive manner. METHODS Juvenile gilthead sea bream (Sparus aurata) were reared at 20-21 °C under normoxic conditions (> 85% O2 saturation) followed by exposure to a gradual decrease in water O2 concentration to 3.0 ppm (41-42% O2 saturation) for 24 h or 1.3 ppm (18-19% O2 saturation) for up to 4 h. Blood samples were collected at three different sampling points for haematological, biochemical and transcriptomic analysis. RESULTS Blood physiological hallmarks remained almost unaltered at 3.0 ppm, but the haematocrit and circulating levels of haemoglobin, glucose and lactate were consistently increased when fish were maintained below the limiting oxygen saturation at 1.3 ppm. These findings were concurrent with an increase in total plasma antioxidant activity and plasma cortisol levels, whereas the opposite trend was observed for growth-promoting factors, such as insulin-like growth factor I. Additionally, gene expression profiling of whole blood cells revealed changes in upstream master regulators of mitochondria (pgcβ and nrf1), antioxidant enzymes (gpx1, gst3, and sod2), outer and inner membrane translocases (tom70, tom22, tim44, tim10, and tim9), components of the mitochondrial dynamics system (mfn2, miffb, miro1a, and miro2), apoptotic factors (aifm1), uncoupling proteins (ucp2) and oxidative enzymes of fatty acid β-oxidation (acca2, ech, and hadh), the tricarboxylic acid cycle (cs) and the oxidative phosphorylation pathway. The overall response is an extensive reduction in gene expression of almost all respiratory chain enzyme subunits of the five complexes, although mitochondrial-encoded catalytic subunits and nuclear-encoded regulatory subunits of Complex IV were primarily increased in hypoxic fish. CONCLUSIONS Our results demonstrate the re-adjustment of mitochondrial machinery at transcriptional level to cope with a decreased basal metabolic rate, consistent with a low risk of oxidative stress, diminished aerobic ATP production and higher O2-carrying capacity. Taken together, these results suggest that whole blood cells can be used as a highly informative target tissue of metabolic condition.
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Affiliation(s)
- Juan Antonio Martos-Sitcha
- Nutrigenomics and Fish Growth Endocrinology Group, Institute of Aquaculture Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC), Ribera de Cabanes, E-12595 Castellón, Spain
| | - Azucena Bermejo-Nogales
- Nutrigenomics and Fish Growth Endocrinology Group, Institute of Aquaculture Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC), Ribera de Cabanes, E-12595 Castellón, Spain
- Present address: Endocrine Disruption and Toxicity of Contaminants, Department of Environment, INIA, Madrid, Spain
| | - Josep Alvar Calduch-Giner
- Nutrigenomics and Fish Growth Endocrinology Group, Institute of Aquaculture Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC), Ribera de Cabanes, E-12595 Castellón, Spain
| | - Jaume Pérez-Sánchez
- Nutrigenomics and Fish Growth Endocrinology Group, Institute of Aquaculture Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC), Ribera de Cabanes, E-12595 Castellón, Spain
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18
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Tissue- and Condition-Specific Isoforms of Mammalian Cytochrome c Oxidase Subunits: From Function to Human Disease. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:1534056. [PMID: 28593021 PMCID: PMC5448071 DOI: 10.1155/2017/1534056] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 03/29/2017] [Indexed: 01/05/2023]
Abstract
Cytochrome c oxidase (COX) is the terminal enzyme of the electron transport chain and catalyzes the transfer of electrons from cytochrome c to oxygen. COX consists of 14 subunits, three and eleven encoded, respectively, by the mitochondrial and nuclear DNA. Tissue- and condition-specific isoforms have only been reported for COX but not for the other oxidative phosphorylation complexes, suggesting a fundamental requirement to fine-tune and regulate the essentially irreversible reaction catalyzed by COX. This article briefly discusses the assembly of COX in mammals and then reviews the functions of the six nuclear-encoded COX subunits that are expressed as isoforms in specialized tissues including those of the liver, heart and skeletal muscle, lung, and testes: COX IV-1, COX IV-2, NDUFA4, NDUFA4L2, COX VIaL, COX VIaH, COX VIb-1, COX VIb-2, COX VIIaH, COX VIIaL, COX VIIaR, COX VIIIH/L, and COX VIII-3. We propose a model in which the isoforms mediate the interconnected regulation of COX by (1) adjusting basal enzyme activity to mitochondrial capacity of a given tissue; (2) allosteric regulation to adjust energy production to need; (3) altering proton pumping efficiency under certain conditions, contributing to thermogenesis; (4) providing a platform for tissue-specific signaling; (5) stabilizing the COX dimer; and (6) modulating supercomplex formation.
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Salvador-Severo K, Gómez-Caudillo L, Quezada H, García-Trejo JDJ, Cárdenas-Conejo A, Vázquez-Memije ME, Minauro-Sanmiguel F. Mitochondrial proteomic profile of complex IV deficiency fibroblasts: rearrangement of oxidative phosphorylation complex/supercomplex and other metabolic pathways. BOLETIN MEDICO DEL HOSPITAL INFANTIL DE MEXICO 2017; 74:175-180. [DOI: 10.1016/j.bmhimx.2017.05.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 05/03/2017] [Accepted: 03/27/2017] [Indexed: 01/10/2023] Open
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Abstract
Respiratory chain dysfunction plays an important role in human disease and aging. It is now well established that the individual respiratory complexes can be organized into supercomplexes, and structures for these macromolecular assemblies, determined by electron cryo-microscopy, have been described recently. Nevertheless, the reason why supercomplexes exist remains an enigma. The widely held view that they enhance catalysis by channeling substrates is challenged by both structural and biophysical information. Here, we evaluate and discuss data and hypotheses on the structures, roles, and assembly of respiratory-chain supercomplexes and propose a future research agenda to address unanswered questions.
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Affiliation(s)
- Dusanka Milenkovic
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9b, 50931 Cologne, Germany
| | - James N Blaza
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, UK
| | - Nils-Göran Larsson
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Strasse 9b, 50931 Cologne, Germany; Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 77 Stockholm, Sweden.
| | - Judy Hirst
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, UK.
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21
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Bourens M, Barrientos A. Human mitochondrial cytochrome c oxidase assembly factor COX18 acts transiently as a membrane insertase within the subunit 2 maturation module. J Biol Chem 2017; 292:7774-7783. [PMID: 28330871 DOI: 10.1074/jbc.m117.778514] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 03/20/2017] [Indexed: 11/06/2022] Open
Abstract
Defects in mitochondrial cytochrome c oxidase or respiratory chain complex IV (CIV) assembly are a frequent cause of human mitochondrial disorders. Specifically, mutations in four conserved assembly factors impinging the biogenesis of the mitochondrion-encoded catalytic core subunit 2 (COX2) result in myopathies. These factors afford stability of newly synthesized COX2 (the dystonia-ataxia syndrome protein COX20), a protein with two transmembrane domains, and maturation of its copper center, CuA (cardiomyopathy proteins SCO1, SCO2, and COA6). COX18 is an additional COX2 assembly factor that belongs to the Oxa1 family of membrane protein insertases. Here, we used a gene-editing approach to generate a human COX18 knock-out HEK293T cell line that displays isolated complete CIV deficiency. We demonstrate that COX20 stabilizes COX2 during insertion of its N-proximal transmembrane domain, and subsequently, COX18 transiently interacts with COX2 to promote translocation across the inner membrane of the COX2 C-tail that contains the apo-CuA site. The release of COX18 from this complex coincides with the binding of the SCO1-SCO2-COA6 copper metallation module to COX2-COX20 to finalize COX2 biogenesis. Therefore, COX18 is a new candidate when screening for mitochondrial disorders associated with isolated CIV deficiency.
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Affiliation(s)
| | - Antoni Barrientos
- From the Departments of Neurology and .,Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, Florida 33136
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Low Cytochrome Oxidase 1 Links Mitochondrial Dysfunction to Atherosclerosis in Mice and Pigs. PLoS One 2017; 12:e0170307. [PMID: 28122051 PMCID: PMC5266248 DOI: 10.1371/journal.pone.0170307] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 01/03/2017] [Indexed: 01/05/2023] Open
Abstract
Background Cytochrome oxidase IV complex regulates energy production in mitochondria. Therefore, we determined the relation of COX genes with atherosclerosis in mice and pigs. Methods and results First, we compared atherosclerosis in the aortic arch of age-matched (24 weeks) C57BL/6J control (n = 10), LDL-receptor deficient (n = 8), leptin-deficient ob/ob (n = 10), and double knock-out (lacking LDL-receptor and leptin) mice (n = 12). Low aortic mitochondria-encoded cytochrome oxidase 1 in obese diabetic double knock-out mice was associated with a larger plaque area and higher propensity of M1 macrophages and oxidized LDL. Caloric restriction increased mitochondria-encoded cytochrome oxidase 1 and reduced plaque area and oxidized LDL. This was associated with a reduction of titer of anti-oxidized LDL antibodies, a proxy of systemic oxidative stress. Low of mitochondria-encoded cytochrome oxidase 1 was related to low expression of peroxisome proliferative activated receptors α, δ, and γ and of peroxisome proliferative activated receptor, gamma, co-activator 1 alpha reflecting mitochondrial dysfunction. Caloric restriction increased them. To investigate if there was a diabetic/obesity requirement for mitochondria-encoded cytochrome oxidase 1 to be down-regulated, we then studied atherosclerosis in LAD of hypercholesterolemic pigs (n = 37). Pigs at the end of the study were divided in three groups based on increasing LAD plaque complexity according to Stary (Stary I: n = 12; Stary II: n = 13; Stary III: n = 12). Low mitochondria-encoded cytochrome oxidase 1 in isolated plaque macrophages was associated with more complex coronary plaques and oxidized LDL. Nucleus-encoded cytochrome oxidase 4I1 and cytochrome oxidase 10 did not correlate with plaque complexity and oxidative stress. In mice and pigs, MT-COI was inversely related to insulin resistance. Conclusions Low MT-COI is related to mitochondrial dysfunction, oxidative stress and atherosclerosis and plaque complexity.
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Cytochrome c Oxidase Biogenesis and Metallochaperone Interactions: Steps in the Assembly Pathway of a Bacterial Complex. PLoS One 2017; 12:e0170037. [PMID: 28107462 PMCID: PMC5249081 DOI: 10.1371/journal.pone.0170037] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 12/27/2016] [Indexed: 12/31/2022] Open
Abstract
Biogenesis of mitochondrial cytochrome c oxidase (COX) is a complex process involving the coordinate expression and assembly of numerous subunits (SU) of dual genetic origin. Moreover, several auxiliary factors are required to recruit and insert the redox-active metal compounds, which in most cases are buried in their protein scaffold deep inside the membrane. Here we used a combination of gel electrophoresis and pull-down assay techniques in conjunction with immunostaining as well as complexome profiling to identify and analyze the composition of assembly intermediates in solubilized membranes of the bacterium Paracoccus denitrificans. Our results show that the central SUI passes through at least three intermediate complexes with distinct subunit and cofactor composition before formation of the holoenzyme and its subsequent integration into supercomplexes. We propose a model for COX biogenesis in which maturation of newly translated COX SUI is initially assisted by CtaG, a chaperone implicated in CuB site metallation, followed by the interaction with the heme chaperone Surf1c to populate the redox-active metal-heme centers in SUI. Only then the remaining smaller subunits are recruited to form the mature enzyme which ultimately associates with respiratory complexes I and III into supercomplexes.
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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: 52] [Impact Index Per Article: 7.4] [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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25
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Screening and Characterization of a Non-cyp51A Mutation in an Aspergillus fumigatus cox10 Strain Conferring Azole Resistance. Antimicrob Agents Chemother 2016; 61:AAC.02101-16. [PMID: 27799210 DOI: 10.1128/aac.02101-16] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 10/18/2016] [Indexed: 12/14/2022] Open
Abstract
The rapid and global emergence of azole resistance in the human pathogen Aspergillus fumigatus has drawn attention. Thus, a thorough understanding of its mechanisms of drug resistance requires extensive exploration. In this study, we found that the loss of the putative calcium-dependent protein-encoding gene algA causes an increased frequency of azole-resistant A. fumigatus isolates. In contrast to previously identified azole-resistant isolates related to cyp51A mutations, only one isolate carries a point mutation in cyp51A (F219L mutation) among 105 independent stable azole-resistant isolates. Through next-generation sequencing (NGS), we successfully identified a new mutation (R243Q substitution) conferring azole resistance in the putative A. fumigatus farnesyltransferase Cox10 (AfCox10) (AFUB_065450). High-performance liquid chromatography (HPLC) analysis verified that the decreased absorption of itraconazole in related Afcox10 mutants is the primary reason for itraconazole resistance. Moreover, a complementation experiment by reengineering the mutation in a parental wild-type background strain demonstrated that both the F219L and R243Q mutations contribute to itraconazole resistance in an algA-independent manner. These data collectively suggest that the loss of algA results in an increased frequency of azole-resistant isolates with a non-cyp51A mutation. Our findings indicate that there are many unexplored non-cyp51A mutations conferring azole resistance in A. fumigatus and that algA defects make it possible to isolate drug-resistant alleles. In addition, our study suggests that genome-wide sequencing combined with alignment comparison analysis is an efficient approach to identify the contribution of single nucleotide polymorphism (SNP) diversity to drug resistance.
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Peralta S, Garcia S, Yin HY, Arguello T, Diaz F, Moraes CT. Sustained AMPK activation improves muscle function in a mitochondrial myopathy mouse model by promoting muscle fiber regeneration. Hum Mol Genet 2016; 25:3178-3191. [PMID: 27288451 PMCID: PMC5179920 DOI: 10.1093/hmg/ddw167] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 04/22/2016] [Accepted: 05/23/2016] [Indexed: 12/25/2022] Open
Abstract
Acute pharmacological activation of adenosine monophosphate (AMP)-kinase using 5-aminoimidazole-4-carboxamide-1-b-D-ribofuranoside (AICAR) has been shown to improve muscle mitochondrial function by increasing mitochondrial biogenesis. We asked whether prolonged AICAR treatment is beneficial in a mouse model of slowly progressing mitochondrial myopathy (Cox10-Mef2c-Cre), and whether the compensatory mechanism is indeed an increase in mitochondrial biogenesis. We treated the animals for 3 months and found that sustained AMP-dependent kinase activation improved cytochrome c oxidase activity, rescued the motor phenotype and delayed the onset of the myopathy. This improvement was observed whether treatment started before or after the onset of the disease. We found that AICAR increased skeletal muscle regeneration thereby decreasing the levels of deleted Cox10-floxed alleles. We conclude that although increase in mitochondrial biogenesis and other pathways may contribute, the main mechanism by which AICAR improves the myopathy phenotype is by promoting muscle regeneration.
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Affiliation(s)
| | | | | | | | | | - Carlos T Moraes
- Department of Neurology
- Genetics Graduate Program
- Department of Cell Biology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
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27
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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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28
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Dennerlein S, Oeljeklaus S, Jans D, Hellwig C, Bareth B, Jakobs S, Deckers M, Warscheid B, Rehling P. MITRAC7 Acts as a COX1-Specific Chaperone and Reveals a Checkpoint during Cytochrome c Oxidase Assembly. Cell Rep 2015; 12:1644-55. [PMID: 26321642 DOI: 10.1016/j.celrep.2015.08.009] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 07/16/2015] [Accepted: 08/03/2015] [Indexed: 11/29/2022] Open
Abstract
Cytochrome c oxidase, the terminal enzyme of the respiratory chain, is assembled from mitochondria- and nuclear-encoded subunits. The MITRAC complex represents the central assembly intermediate during this process as it receives imported subunits and regulates mitochondrial translation of COX1 mRNA. The molecular processes that promote and regulate the progression of assembly downstream of MITRAC are still unknown. Here, we identify MITRAC7 as a constituent of a late form of MITRAC and as a COX1-specific chaperone. MITRAC7 is required for cytochrome c oxidase biogenesis. Surprisingly, loss of MITRAC7 or an increase in its amount causes selective cytochrome c oxidase deficiency in human cells. We demonstrate that increased MITRAC7 levels stabilize and trap COX1 in MITRAC, blocking progression in the assembly process. In contrast, MITRAC7 deficiency leads to turnover of newly synthesized COX1. Accordingly, MITRAC7 affects the biogenesis pathway by stabilizing newly synthesized COX1 in assembly intermediates, concomitantly preventing turnover.
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Affiliation(s)
- Sven Dennerlein
- Department of Cellular Biochemistry, University of Göttingen, 37073 Göttingen, Germany
| | - Silke Oeljeklaus
- Department of Biochemistry and Functional Proteomics, Faculty of Biology and BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Daniel Jans
- Department of NanoBiophotonics, Mitochondrial Structure and Dynamics Group, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Christin Hellwig
- Department of Cellular Biochemistry, University of Göttingen, 37073 Göttingen, Germany
| | - Bettina Bareth
- Department of Cellular Biochemistry, University of Göttingen, 37073 Göttingen, Germany
| | - Stefan Jakobs
- Department of NanoBiophotonics, Mitochondrial Structure and Dynamics Group, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany; Department of Neurology, University of Göttingen, 37073 Göttingen, Germany
| | - Markus Deckers
- Department of Cellular Biochemistry, University of Göttingen, 37073 Göttingen, Germany
| | - Bettina Warscheid
- Department of Biochemistry and Functional Proteomics, Faculty of Biology and BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Peter Rehling
- Department of Cellular Biochemistry, University of Göttingen, 37073 Göttingen, Germany; Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
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29
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Van der Schueren B, Vangoitsenhoven R, Geeraert B, De Keyzer D, Hulsmans M, Lannoo M, Huber HJ, Mathieu C, Holvoet P. Low cytochrome oxidase 4I1 links mitochondrial dysfunction to obesity and type 2 diabetes in humans and mice. Int J Obes (Lond) 2015; 39:1254-63. [PMID: 25869607 DOI: 10.1038/ijo.2015.58] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 03/19/2015] [Accepted: 04/04/2015] [Indexed: 12/31/2022]
Abstract
OBJECTIVES Cytochrome oxidase (COX) dysfunction is associated with mitochondrial oxidative stress. We determined the association between COX expression, obesity and type 2 diabetes. SUBJECTS/METHODS COX4I1 and COX10 genes were measured in monocytes of 24 lean controls, 31 glucose-tolerant and 67 diabetic obese patients, and 17 morbidly obese patients before and after bariatric surgery. We investigated the effect of caloric restriction and peroxisome proliferator-activated receptor (PPAR) agonist treatment on Cox in obese diabetic mice, and that of diet-induced insulin resistance in Streptozotocin-treated mice. RESULTS Low COX4I1 was associated with type 2 diabetes in obese patients, adjusting for age, gender, smoking, interleukin-6 and high-sensitivity C-reactive protein, all related to metabolic syndrome (MetS; odds ratio: 6.1, 95% confidence interval: 2.3-16). In contrast, COX10 was low in glucose-tolerant and diabetic obese patients. In morbidly obese patients, COX4I1 was lower in visceral adipose tissue collected at bariatric surgery. In their monocytes, COX4I1 decreased after bariatric surgery, and low COX4I1 at 4 months was associated with MetS at 7 years. In leptin-deficient obese diabetic mice, Cox4i1 was low in white visceral adipose tissue (n=13; P<0.001) compared with age-matched lean mice (n=10). PPARγ-agonist treatment (n=13), but not caloric restriction (n=11), increased Cox4i1 (P<0.001). Increase in Cox4i1 depended on the increase in glucose transporter 4 (Glut4) expression and insulin sensitivity, independent of the increase in blood adiponectin. In streptozotocin-treated mice (three groups of seven mice, diet-induced insulin resistance decreased Cox4i1 and Glut4 (P<0.001 for both). CONCLUSION COX4I1 depression is related to insulin resistance and type 2 diabetes in obesity. In peripheral blood monocytes, it may be a diagnostically useful biomarker.
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Affiliation(s)
- B Van der Schueren
- Laboratory for Clinical and Experimental Medicine and Endocrinology, KU Leuven, Leuven, Belgium
| | - R Vangoitsenhoven
- Laboratory for Clinical and Experimental Medicine and Endocrinology, KU Leuven, Leuven, Belgium
| | - B Geeraert
- Division of Atherosclerosis and Metabolism, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - D De Keyzer
- Division of Atherosclerosis and Metabolism, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - M Hulsmans
- Division of Atherosclerosis and Metabolism, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - M Lannoo
- Laboratory for Clinical and Experimental Medicine and Endocrinology, KU Leuven, Leuven, Belgium
| | - H J Huber
- Division of Atherosclerosis and Metabolism, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - C Mathieu
- Laboratory for Clinical and Experimental Medicine and Endocrinology, KU Leuven, Leuven, Belgium
| | - P Holvoet
- Division of Atherosclerosis and Metabolism, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
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30
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Exposure to a northern contaminant mixture (NCM) alters hepatic energy and lipid metabolism exacerbating hepatic steatosis in obese JCR rats. PLoS One 2014; 9:e106832. [PMID: 25222487 PMCID: PMC4164366 DOI: 10.1371/journal.pone.0106832] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 08/01/2014] [Indexed: 12/22/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD), defined by the American Liver Society as the buildup of extra fat in liver cells that is not caused by alcohol, is the most common liver disease in North America. Obesity and type 2 diabetes are viewed as the major causes of NAFLD. Environmental contaminants have also been implicated in the development of NAFLD. Northern populations are exposed to a myriad of persistent organic pollutants including polychlorinated biphenyls, organochlorine pesticides, flame retardants, and toxic metals, while also affected by higher rates of obesity and alcohol abuse compared to the rest of Canada. In this study, we examined the impact of a mixture of 22 contaminants detected in Inuit blood on the development and progression of NAFLD in obese JCR rats with or without co-exposure to10% ethanol. Hepatosteatosis was found in obese rat liver, which was worsened by exposure to 10% ethanol. NCM treatment increased the number of macrovesicular lipid droplets, total lipid contents, portion of mono- and polyunsaturated fatty acids in the liver. This was complemented by an increase in hepatic total cholesterol and cholesterol ester levels which was associated with changes in the expression of genes and proteins involved in lipid metabolism and transport. In addition, NCM treatment increased cytochrome P450 2E1 protein expression and decreased ubiquinone pool, and mitochondrial ATP synthase subunit ATP5A and Complex IV activity. Despite the changes in mitochondrial physiology, hepatic ATP levels were maintained high in NCM-treated versus control rats. This was due to a decrease in ATP utilization and an increase in creatine kinase activity. Collectively, our results suggest that NCM treatment decreases hepatic cholesterol export, possibly also increases cholesterol uptake from circulation, and promotes lipid accumulation and alters ATP homeostasis which exacerbates the existing hepatic steatosis in genetically obese JCR rats with or without co-exposure to ethanol.
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31
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Mitochondrial ROS and involvement of Bcl-2 as a mitochondrial ROS regulator. Mitochondrion 2014; 19 Pt A:39-48. [PMID: 24954615 DOI: 10.1016/j.mito.2014.06.002] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 06/06/2014] [Accepted: 06/12/2014] [Indexed: 12/22/2022]
Abstract
Mitochondria are the major intracellular source of reactive oxygen species (ROS). While excessive mitochondrial ROS (mitoROS) production induces cell injury and death, there is accumulating evidence that non-toxic low levels of mitoROS could serve as important signaling molecules. Therefore, maintenance of mitoROS at physiological levels is crucial for cell homeostasis as well as for survival and proliferation. This review describes the various mechanisms that keep mitoROS in check, with particular focus on the role of the onco-protein Bcl-2 in redox regulation. In addition to its canonical anti-apoptotic activity, Bcl-2 has been implicated in mitoROS regulation by its effect on mitochondrial complex IV activity, facilitating the mitochondrial incorporation of GSH and interaction with the small GTPase-Rac1 at the mitochondria. We also discuss some of the plausible mechanism(s) which allows Bcl-2 to sense and respond to the fluctuations in mitoROS.
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32
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Cui TZ, Conte A, Fox JL, Zara V, Winge DR. Modulation of the respiratory supercomplexes in yeast: enhanced formation of cytochrome oxidase increases the stability and abundance of respiratory supercomplexes. J Biol Chem 2014; 289:6133-41. [PMID: 24421313 DOI: 10.1074/jbc.m113.523688] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Yeast cells deficient in the Rieske iron-sulfur subunit (Rip1) of ubiquinol-cytochrome c reductase (bc1) accumulate a late core assembly intermediate, which weakly associates with cytochrome oxidase (CcO) in a respiratory supercomplex. Expression of the N-terminal half of Rip1, which lacks the C-terminal FeS-containing globular domain (designated N-Rip1), results in a marked stabilization of trimeric and tetrameric bc1-CcO supercomplexes. Another bc1 mutant (qcr9Δ) stalled at the same assembly intermediate is likewise converted to stable supercomplex species by the expression of N-Rip1, but not by expression of intact Rip1. The N-Rip1-induced stabilization of bc1-CcO supercomplexes is independent of the Bcs1 translocase, which mediates Rip1 translocation during bc1 biogenesis. N-Rip1 induces the stabilization of bc1-CcO supercomplexes through an enhanced formation of CcO. The association of N-Rip1 with the late core bc1 assembly intermediate appears to confer stabilization of a CcO assembly intermediate. This induced stabilization of CcO is dependent on the Rcf1 supercomplex stabilization factor and only partially dependent on the presence of cardiolipin. N-Rip1 exerts a related induction of CcO stabilization in WT yeast, resulting in enhanced respiration. Additionally, the impact of CcO stabilization on supercomplexes was observed by means other than expression of N-Rip1 (via overexpression of CcO subunits Cox4 and Cox5a), demonstrating that this is a general phenomenon. This study presents the first evidence showing that supercomplexes can be stabilized by the stimulated formation of CcO.
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Affiliation(s)
- Tie-Zhong Cui
- From the Departments of Medicine and Biochemistry, University of Utah Health Sciences Center, Salt Lake City, Utah 84132 and
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33
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Bourens M, Boulet A, Leary SC, Barrientos A. Human COX20 cooperates with SCO1 and SCO2 to mature COX2 and promote the assembly of cytochrome c oxidase. Hum Mol Genet 2014; 23:2901-13. [PMID: 24403053 DOI: 10.1093/hmg/ddu003] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Cytochrome c oxidase (CIV) deficiency is one of the most common respiratory chain defects in patients presenting with mitochondrial encephalocardiomyopathies. CIV biogenesis is complicated by the dual genetic origin of its structural subunits, and assembly of a functional holoenzyme complex requires a large number of nucleus-encoded assembly factors. In general, the functions of these assembly factors remain poorly understood, and mechanistic investigations of human CIV biogenesis have been limited by the availability of model cell lines. Here, we have used small interference RNA and transcription activator-like effector nucleases (TALENs) technology to create knockdown and knockout human cell lines, respectively, to study the function of the CIV assembly factor COX20 (FAM36A). These cell lines exhibit a severe, isolated CIV deficiency due to instability of COX2, a mitochondrion-encoded CIV subunit. Mitochondria lacking COX20 accumulate CIV subassemblies containing COX1 and COX4, similar to those detected in fibroblasts from patients carrying mutations in the COX2 copper chaperones SCO1 and SCO2. These results imply that in the absence of COX20, COX2 is inefficiently incorporated into early CIV subassemblies. Immunoprecipitation assays using a stable COX20 knockout cell line expressing functional COX20-FLAG allowed us to identify an interaction between COX20 and newly synthesized COX2. Additionally, we show that SCO1 and SCO2 act on COX20-bound COX2. We propose that COX20 acts as a chaperone in the early steps of COX2 maturation, stabilizing the newly synthesized protein and presenting COX2 to its metallochaperone module, which in turn facilitates the incorporation of mature COX2 into the CIV assembly line.
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Kemppainen KK, Rinne J, Sriram A, Lakanmaa M, Zeb A, Tuomela T, Popplestone A, Singh S, Sanz A, Rustin P, Jacobs HT. Expression of alternative oxidase in Drosophila ameliorates diverse phenotypes due to cytochrome oxidase deficiency. Hum Mol Genet 2013; 23:2078-93. [PMID: 24293544 PMCID: PMC3959817 DOI: 10.1093/hmg/ddt601] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Mitochondrial dysfunction is a significant factor in human disease, ranging from systemic disorders of childhood to cardiomyopathy, ischaemia and neurodegeneration. Cytochrome oxidase, the terminal enzyme of the mitochondrial respiratory chain, is a frequent target. Lower eukaryotes possess alternative respiratory-chain enzymes that provide non-proton-translocating bypasses for respiratory complexes I (single-subunit reduced nicotinamide adenine dinucleotide dehydrogenases, e.g. Ndi1 from yeast) or III + IV [alternative oxidase (AOX)], under conditions of respiratory stress or overload. In previous studies, it was shown that transfer of yeast Ndi1 or Ciona intestinalis AOX to Drosophila was able to overcome the lethality produced by toxins or partial knockdown of complex I or IV. Here, we show that AOX can provide a complete or substantial rescue of a range of phenotypes induced by global or tissue-specific knockdown of different cIV subunits, including integral subunits required for catalysis, as well as peripheral subunits required for multimerization and assembly. AOX was also able to overcome the pupal lethality produced by muscle-specific knockdown of subunit CoVb, although the rescued flies were short lived and had a motility defect. cIV knockdown in neurons was not lethal during development but produced a rapidly progressing locomotor and seizure-sensitivity phenotype, which was substantially alleviated by AOX. Expression of Ndi1 exacerbated the neuronal phenotype produced by cIV knockdown. Ndi1 expressed in place of essential cI subunits produced a distinct residual phenotype of delayed development, bang sensitivity and male sterility. These findings confirm the potential utility of alternative respiratory chain enzymes as tools to combat mitochondrial disease, while indicating important limitations thereof.
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Affiliation(s)
- Kia K Kemppainen
- Institute of Biomedical Technology and Tampere University Hospital, University of Tampere, FI-33014 Tampere, Finland
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35
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Pitceathly RDS, Rahman S, Wedatilake Y, Polke JM, Cirak S, Foley AR, Sailer A, Hurles ME, Stalker J, Hargreaves I, Woodward CE, Sweeney MG, Muntoni F, Houlden H, Taanman JW, Hanna MG. NDUFA4 mutations underlie dysfunction of a cytochrome c oxidase subunit linked to human neurological disease. Cell Rep 2013; 3:1795-805. [PMID: 23746447 PMCID: PMC3701321 DOI: 10.1016/j.celrep.2013.05.005] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Revised: 04/29/2013] [Accepted: 05/03/2013] [Indexed: 11/15/2022] Open
Abstract
The molecular basis of cytochrome c oxidase (COX, complex IV) deficiency remains genetically undetermined in many cases. Homozygosity mapping and whole-exome sequencing were performed in a consanguineous pedigree with isolated COX deficiency linked to a Leigh syndrome neurological phenotype. Unexpectedly, affected individuals harbored homozygous splice donor site mutations in NDUFA4, a gene previously assigned to encode a mitochondrial respiratory chain complex I (NADH:ubiquinone oxidoreductase) subunit. Western blot analysis of denaturing gels and immunocytochemistry revealed undetectable steady-state NDUFA4 protein levels, indicating that the mutation causes a loss-of-function effect in the homozygous state. Analysis of one- and two-dimensional blue-native polyacrylamide gels confirmed an interaction between NDUFA4 and the COX enzyme complex in control muscle, whereas the COX enzyme complex without NDUFA4 was detectable with no abnormal subassemblies in patient muscle. These observations support recent work in cell lines suggesting that NDUFA4 is an additional COX subunit and demonstrate that NDUFA4 mutations cause human disease. Our findings support reassignment of the NDUFA4 protein to complex IV and suggest that patients with unexplained COX deficiency should be screened for NDUFA4 mutations.
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Affiliation(s)
- Robert D S Pitceathly
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
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36
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Fontanesi F. Mechanisms of mitochondrial translational regulation. IUBMB Life 2013; 65:397-408. [PMID: 23554047 DOI: 10.1002/iub.1156] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 01/31/2013] [Indexed: 11/11/2022]
Abstract
The mitochondrial oxidative phosphorylation system is formed by multimeric enzymes. In the yeast Saccharomyces cerevisiae, the bc1 complex, cytochrome c oxidase and the F1 FO ATP synthase contain subunits of dual genetic origin. It has been recently established that key subunits of these enzymes, translated on mitochondrial ribosomes, are the subjects of assembly-dependent translational regulation. This type of control of gene expression plays a pivotal role in optimizing the biogenesis of mitochondrial respiratory membranes by coordinating protein synthesis and complex assembly and by limiting the accumulation of potentially harmful assembly intermediates. Here, the author will discuss the mechanisms governing translational regulation in yeast mitochondria in the light of the most recent discoveries in the field.
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Affiliation(s)
- Flavia Fontanesi
- Department of Neurology, University of Miami, Miller School of Medicine, Miami, FL, USA.
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37
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Clemente P, Peralta S, Cruz-Bermudez A, Echevarría L, Fontanesi F, Barrientos A, Fernandez-Moreno MA, Garesse R. hCOA3 stabilizes cytochrome c oxidase 1 (COX1) and promotes cytochrome c oxidase assembly in human mitochondria. J Biol Chem 2013; 288:8321-8331. [PMID: 23362268 DOI: 10.1074/jbc.m112.422220] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cytochrome c oxidase (COX) or complex IV of the mitochondrial respiratory chain plays a fundamental role in energy production of aerobic cells. In humans, COX deficiency is the most frequent cause of mitochondrial encephalomyopathies. Human COX is composed of 13 subunits of dual genetic origin, whose assembly requires an increasing number of nuclear-encoded accessory proteins known as assembly factors. Here, we have identified and characterized human CCDC56, an 11.7-kDa mitochondrial transmembrane protein, as a new factor essential for COX biogenesis. CCDC56 shares sequence similarity with the yeast COX assembly factor Coa3 and was termed hCOA3. hCOA3-silenced cells display a severe COX functional alteration owing to a decreased stability of newly synthesized COX1 and an impairment in the holoenzyme assembly process. We show that hCOA3 physically interacts with both the mitochondrial translation machinery and COX structural subunits. We conclude that hCOA3 stabilizes COX1 co-translationally and promotes its assembly with COX partner subunits. Finally, our results identify hCOA3 as a new candidate when screening for genes responsible for mitochondrial diseases associated with COX deficiency.
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Affiliation(s)
- Paula Clemente
- Departamento de Bioquímica, Universidad Autónoma de Madrid, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-Consejo Superior de Investigaciones Científicas and Centro de Investigación Biomédica en Red de Enfermedades Raras, 28029 Madrid, Spain; Instituto de Investigación Sanitaria Hospital 12 de Octubre (i+12), 28029 Madrid, Spain
| | - Susana Peralta
- Departamento de Bioquímica, Universidad Autónoma de Madrid, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-Consejo Superior de Investigaciones Científicas and Centro de Investigación Biomédica en Red de Enfermedades Raras, 28029 Madrid, Spain
| | - Alberto Cruz-Bermudez
- Departamento de Bioquímica, Universidad Autónoma de Madrid, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-Consejo Superior de Investigaciones Científicas and Centro de Investigación Biomédica en Red de Enfermedades Raras, 28029 Madrid, Spain; Instituto de Investigación Sanitaria Hospital 12 de Octubre (i+12), 28029 Madrid, Spain
| | - Lucía Echevarría
- Departamento de Bioquímica, Universidad Autónoma de Madrid, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-Consejo Superior de Investigaciones Científicas and Centro de Investigación Biomédica en Red de Enfermedades Raras, 28029 Madrid, Spain; Instituto de Investigación Sanitaria Hospital 12 de Octubre (i+12), 28029 Madrid, Spain
| | - Flavia Fontanesi
- Department of Neurology, University of Miami, Miller School of Medicine, Miami, Florida 33136
| | - Antoni Barrientos
- Department of Neurology, University of Miami, Miller School of Medicine, Miami, Florida 33136; Department of Biochemistry, University of Miami, Miller School of Medicine, Miami, Florida 33136
| | - Miguel A Fernandez-Moreno
- Departamento de Bioquímica, Universidad Autónoma de Madrid, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-Consejo Superior de Investigaciones Científicas and Centro de Investigación Biomédica en Red de Enfermedades Raras, 28029 Madrid, Spain; Instituto de Investigación Sanitaria Hospital 12 de Octubre (i+12), 28029 Madrid, Spain; MITOLAB Consortium P2010/BMD-2402, Comunidad de Madrid, 28029 Madrid, Spain
| | - Rafael Garesse
- Departamento de Bioquímica, Universidad Autónoma de Madrid, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-Consejo Superior de Investigaciones Científicas and Centro de Investigación Biomédica en Red de Enfermedades Raras, 28029 Madrid, Spain; Instituto de Investigación Sanitaria Hospital 12 de Octubre (i+12), 28029 Madrid, Spain; MITOLAB Consortium P2010/BMD-2402, Comunidad de Madrid, 28029 Madrid, Spain.
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38
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Soto IC, Fontanesi F, Liu J, Barrientos A. Biogenesis and assembly of eukaryotic cytochrome c oxidase catalytic core. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1817:883-97. [PMID: 21958598 PMCID: PMC3262112 DOI: 10.1016/j.bbabio.2011.09.005] [Citation(s) in RCA: 159] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 09/07/2011] [Accepted: 09/12/2011] [Indexed: 10/17/2022]
Abstract
Eukaryotic cytochrome c oxidase (COX) is the terminal enzyme of the mitochondrial respiratory chain. COX is a multimeric enzyme formed by subunits of dual genetic origin which assembly is intricate and highly regulated. The COX catalytic core is formed by three mitochondrial DNA encoded subunits, Cox1, Cox2 and Cox3, conserved in the bacterial enzyme. Their biogenesis requires the action of messenger-specific and subunit-specific factors which facilitate the synthesis, membrane insertion, maturation or assembly of the core subunits. The study of yeast strains and human cell lines from patients carrying mutations in structural subunits and COX assembly factors has been invaluable to identify these ancillary factors. Here we review the current state of knowledge of the biogenesis and assembly of the eukaryotic COX catalytic core and discuss the degree of conservation of the players and mechanisms operating from yeast to human. This article is part of a Special Issue entitled: Biogenesis/Assembly of Respiratory Enzyme Complexes.
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Affiliation(s)
- Ileana C. Soto
- Department of Biochemistry & Molecular Biology, University of Miami Miller School of Medicine. Miami, FL
| | - Flavia Fontanesi
- Department of Neurology. University of Miami Miller School of Medicine. Miami, FL
| | - Jingjing Liu
- Department of Biochemistry & Molecular Biology, University of Miami Miller School of Medicine. Miami, FL
| | - Antoni Barrientos
- Department of Biochemistry & Molecular Biology, University of Miami Miller School of Medicine. Miami, FL
- Department of Neurology. University of Miami Miller School of Medicine. Miami, FL
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39
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Kim HJ, Khalimonchuk O, Smith PM, Winge DR. Structure, function, and assembly of heme centers in mitochondrial respiratory complexes. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1823:1604-16. [PMID: 22554985 DOI: 10.1016/j.bbamcr.2012.04.008] [Citation(s) in RCA: 157] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 04/11/2012] [Accepted: 04/13/2012] [Indexed: 10/28/2022]
Abstract
The sequential flow of electrons in the respiratory chain, from a low reduction potential substrate to O(2), is mediated by protein-bound redox cofactors. In mitochondria, hemes-together with flavin, iron-sulfur, and copper cofactors-mediate this multi-electron transfer. Hemes, in three different forms, are used as a protein-bound prosthetic group in succinate dehydrogenase (complex II), in bc(1) complex (complex III) and in cytochrome c oxidase (complex IV). The exact function of heme b in complex II is still unclear, and lags behind in operational detail that is available for the hemes of complex III and IV. The two b hemes of complex III participate in the unique bifurcation of electron flow from the oxidation of ubiquinol, while heme c of the cytochrome c subunit, Cyt1, transfers these electrons to the peripheral cytochrome c. The unique heme a(3), with Cu(B), form a catalytic site in complex IV that binds and reduces molecular oxygen. In addition to providing catalytic and electron transfer operations, hemes also serve a critical role in the assembly of these respiratory complexes, which is just beginning to be understood. In the absence of heme, the assembly of complex II is impaired, especially in mammalian cells. In complex III, a covalent attachment of the heme to apo-Cyt1 is a prerequisite for the complete assembly of bc(1), whereas in complex IV, heme a is required for the proper folding of the Cox 1 subunit and subsequent assembly. In this review, we provide further details of the aforementioned processes with respect to the hemes of the mitochondrial respiratory complexes. This article is part of a Special Issue entitled: Cell Biology of Metals.
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Affiliation(s)
- Hyung J Kim
- University of Utah Health Sciences Center, Department of Medicine, Salt Lake City, UT 84132, USA
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40
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Hornig-Do HT, Tatsuta T, Buckermann A, Bust M, Kollberg G, Rötig A, Hellmich M, Nijtmans L, Wiesner RJ. Nonsense mutations in the COX1 subunit impair the stability of respiratory chain complexes rather than their assembly. EMBO J 2012; 31:1293-307. [PMID: 22252130 PMCID: PMC3297988 DOI: 10.1038/emboj.2011.477] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 12/01/2011] [Indexed: 01/22/2023] Open
Abstract
Respiratory chain (RC) complexes are organized into supercomplexes forming 'respirasomes'. The mechanism underlying the interdependence of individual complexes is still unclear. Here, we show in human patient cells that the presence of a truncated COX1 subunit leads to destabilization of complex IV (CIV) and other RC complexes. Surprisingly, the truncated COX1 protein is integrated into subcomplexes, the holocomplex and even into supercomplexes, which however are all unstable. Depletion of the m-AAA protease AFG3L2 increases stability of the truncated COX1 and other mitochondrially encoded proteins, whereas overexpression of wild-type AFG3L2 decreases their stability. Both full-length and truncated COX1 proteins physically interact with AFG3L2. Expression of a dominant negative AFG3L2 variant also promotes stabilization of CIV proteins as well as the assembled complex and rescues the severe phenotype in heteroplasmic cells. Our data indicate that the mechanism underlying pathogenesis in these patients is the rapid clearance of unstable respiratory complexes by quality control pathways, rather than their impaired assembly.
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Affiliation(s)
- Hue-Tran Hornig-Do
- Institute for Vegetative Physiology, University of Cologne, Cologne, Germany
| | - Takashi Tatsuta
- Institute for Genetics, University of Cologne, Cologne, Germany
| | - Angela Buckermann
- Institute for Vegetative Physiology, University of Cologne, Cologne, Germany
| | - Maria Bust
- Institute for Vegetative Physiology, University of Cologne, Cologne, Germany
| | - Gittan Kollberg
- Department of Clinical Chemistry, Sahlgrenska University Hospital, Göteborg, Sweden
| | - Agnes Rötig
- INSERM U781, Hôpital Necker-Enfants Malades, Université René Descartes, Paris, France
| | - Martin Hellmich
- Institute of Medical Statistics, Informatics and Epidemiology, Cologne, Germany
| | - Leo Nijtmans
- Department of Pediatrics, Nijmegen Center for Mitochondrial Disorders, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
| | - Rudolf J Wiesner
- Institute for Vegetative Physiology, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne, CMMC, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
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41
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DiMauro S, Tanji K, Schon EA. The Many Clinical Faces of Cytochrome c Oxidase Deficiency. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 748:341-57. [DOI: 10.1007/978-1-4614-3573-0_14] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Assembly Factors of Human Mitochondrial Respiratory Chain Complexes: Physiology and Pathophysiology. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 748:65-106. [DOI: 10.1007/978-1-4614-3573-0_4] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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43
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Low ICC, Kang J, Pervaiz S. Bcl-2: a prime regulator of mitochondrial redox metabolism in cancer cells. Antioxid Redox Signal 2011; 15:2975-87. [PMID: 21574773 DOI: 10.1089/ars.2010.3851] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
SIGNIFICANCE Mitochondria play a critical role as death amplifiers during drug-induced apoptosis in cancer cells by providing pro-apoptotic factors that are released from the mitochondrial inter-membranous space upon the induction of mitochondrial outer membrane permeabilization. This intrinsic death signaling pathway is the preferred mechanism employed by most anticancer compounds, and as such, resistance to drug-induced apoptosis is invariably associated with inhibition of mitochondrial death signaling network. The latter is a function of a balance between the pro- and the anti-apoptotic members of the Bcl-2 family. Bcl-2 is the prototype anti-apoptotic protein that localizes to the mitochondria and blocks the recruitment and activation of pro-apoptotic proteins, such as Bax, to the mitochondria. RECENT ADVANCES AND CRITICAL ISSUES Recent evidence has highlighted a novel mechanism of anti-apoptotic activity of Bcl-2 in addition to its canonical activity in regulating mitochondrial outer membrane permeabilization. This novel activity is a function of cellular redox regulation, in particular, mitochondrial metabolism in cancer cells. FUTURE DIRECTIONS Here we review the current state of our understanding of the death inhibitory activity of Bcl-2 and provide insight into the novel functional biology of this remarkable protein, which could have implications for designing innovative strategies to overcome the problem of drug resistance in the clinical settings.
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Affiliation(s)
- Ivan Cherh Chiet Low
- ROS, Apoptosis and Cancer Biology Laboratory, Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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44
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Hébert Chatelain E, Dupuy JW, Letellier T, Dachary-Prigent J. Functional impact of PTP1B-mediated Src regulation on oxidative phosphorylation in rat brain mitochondria. Cell Mol Life Sci 2011; 68:2603-13. [PMID: 21063895 PMCID: PMC11115002 DOI: 10.1007/s00018-010-0573-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Revised: 10/04/2010] [Accepted: 10/15/2010] [Indexed: 01/08/2023]
Abstract
Given the presence of Src and PTP1B within rat brain mitochondria, we have investigated whether PTP1B regulates Src activity in mitochondria as in the cytosol. Results showed that Src was stimulated by in vitro addition of ATP to mitochondria, and this stimulation was reversed by a membrane-permeable allosteric inhibitor of PTP1B and by a potent selective Src inhibitor. They also indicated a direct action of PTP1B on phosphorylated tyrosine 527 residue of Src, thus implicating a role for PTP1B in the modulation of Src activity in mitochondria. Putative Src and PTP1B substrates were identified by liquid chromatography tandem mass spectrometry and two-dimensional blue native/SDS-PAGE. Both inhibitors inhibited ADP-stimulated respirations concurrently with Src activation and complex IV activation by ATP, while having no effect or increasing the activity of the other complexes. Our analysis emphasizes the regulatory function of Src and its modulation by PTP1B on oxidative phosphorylation in mitochondria.
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Affiliation(s)
- Etienne Hébert Chatelain
- Physiopathologie Mitochondriale, INSERM-U688, Université Victor Ségalen-Bordeaux 2, 146 rue Léo Saignat, 33076, Bordeaux-Cedex, France.
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45
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Hypoxic and hypercapnic challenges unveil respiratory vulnerability of Surf1 knockout mice, an animal model of Leigh syndrome. Mitochondrion 2011; 11:413-20. [DOI: 10.1016/j.mito.2010.12.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Revised: 10/18/2010] [Accepted: 12/08/2010] [Indexed: 12/23/2022]
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46
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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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47
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Inventory control: cytochrome c oxidase assembly regulates mitochondrial translation. Nat Rev Mol Cell Biol 2011; 12:14-20. [PMID: 21179059 DOI: 10.1038/nrm3029] [Citation(s) in RCA: 164] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mitochondria maintain genome and translation machinery to synthesize a small subset of subunits of the oxidative phosphorylation system. To build up functional enzymes, these organellar gene products must assemble with imported subunits that are encoded in the nucleus. New findings on the early steps of cytochrome c oxidase assembly reveal how the mitochondrial translation of its core component, cytochrome c oxidase subunit 1 (Cox1), is directly coupled to the assembly of this respiratory complex.
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48
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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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49
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Fontanesi F, Clemente P, Barrientos A. Cox25 teams up with Mss51, Ssc1, and Cox14 to regulate mitochondrial cytochrome c oxidase subunit 1 expression and assembly in Saccharomyces cerevisiae. J Biol Chem 2010; 286:555-66. [PMID: 21068384 DOI: 10.1074/jbc.m110.188805] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
In the yeast Saccharomyces cerevisiae, mitochondrial cytochrome c oxidase (COX) biogenesis is translationally regulated. Mss51, a specific COX1 mRNA translational activator and Cox1 chaperone, drives the regulatory mechanism. During translation and post-translationally, newly synthesized Cox1 physically interacts with a complex of proteins involving Ssc1, Mss51, and Cox14, which eventually hand over Cox1 to the assembly pathway. This step is probably catalyzed by assembly chaperones such as Shy1 in a process coupled to the release of Ssc1-Mss51 from the complex. Impaired COX assembly results in the trapping of Mss51 in the complex, thus limiting its availability for COX1 mRNA translation. An exception is a null mutation in COX14 that does not affect Cox1 synthesis because the Mss51 trapping complexes become unstable, and Mss51 is readily available for translation. Here we present evidence showing that Cox25 is a new essential COX assembly factor that plays some roles similar to Cox14. A null mutation in COX25 by itself or in combination with other COX mutations does not affect Cox1 synthesis. Cox25 is an inner mitochondrial membrane intrinsic protein with a hydrophilic C terminus protruding into the matrix. Cox25 is an essential component of the complexes containing newly synthesized Cox1, Ssc1, Mss51, and Cox14. In addition, Cox25 is also found to interact with Shy1 and Cox5 in a complex that does not contain Mss51. These results suggest that once Ssc1-Mss51 are released from the Cox1 stabilization complex, Cox25 continues to interact with Cox14 and Cox1 to facilitate the formation of multisubunit COX assembly intermediates.
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Affiliation(s)
- Flavia Fontanesi
- Departments of Neurology, University of Miami Miller School of Medicine, Miami, Florida 33136, USA
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50
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Leary SC. Redox regulation of SCO protein function: controlling copper at a mitochondrial crossroad. Antioxid Redox Signal 2010; 13:1403-16. [PMID: 20136502 DOI: 10.1089/ars.2010.3116] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Reversible changes in the redox state of cysteine residues represent an important mechanism with which to regulate protein function. In mitochondria, such redox reactions modulate the localization or activity of a group of proteins, most of which function in poorly defined pathways with essential roles in copper delivery to cytochrome c oxidase (COX) during holoenzyme biogenesis. To date, a total of 8 soluble (COX17, COX19, COX23, PET191, CMC1-4) and 3 integral membrane (COX11, SCO1, SCO2) accessory proteins with cysteine-containing domains that reside within the mitochondrial intermembrane space (IMS) have been identified in yeast, all of which have human orthologues. Compelling evidence from studies of COX17, SCO1, and SCO2 argues that regulation of the redox state of their cysteines is integral to their metallochaperone function. Redox also appears to be crucial to the regulation of a SCO-dependent, mitochondrial signaling pathway that modulates the rate of copper efflux from the cell. Here, I review our understanding of redox-dependent modulation of copper delivery to COX and IMS-localized copper-zinc superoxide dismutase (SOD1) during the maturation of each enzyme, and discuss how this in turn may serve to functionally couple mitochondrial copper handling pathways with those localized elsewhere in the cell to regulate cellular copper homeostasis.
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Affiliation(s)
- Scot C Leary
- Department of Biochemistry, University of Saskatchewan, Saskatoon, Canada.
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