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Čunátová K, Vrbacký M, Puertas-Frias G, Alán L, Vanišová M, Saucedo-Rodríguez MJ, Houštěk J, Fernández-Vizarra E, Neužil J, Pecinová A, Pecina P, Mráček T. Mitochondrial translation is the primary determinant of secondary mitochondrial complex I deficiencies. iScience 2024; 27:110560. [PMID: 39184436 PMCID: PMC11342289 DOI: 10.1016/j.isci.2024.110560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 03/28/2024] [Accepted: 07/17/2024] [Indexed: 08/27/2024] Open
Abstract
Individual complexes of the mitochondrial oxidative phosphorylation system (OXPHOS) are not linked solely by their function; they also share dependencies at the maintenance/assembly level, where one complex depends on the presence of a different individual complex. Despite the relevance of this "interdependence" behavior for mitochondrial diseases, its true nature remains elusive. To understand the mechanism that can explain this phenomenon, we examined the consequences of the aberration of different OXPHOS complexes in human cells. We demonstrate here that the complete disruption of each of the OXPHOS complexes resulted in a decrease in the complex I (cI) level and that the major reason for this is linked to the downregulation of mitochondrial ribosomal proteins. We conclude that the secondary cI defect is due to mitochondrial protein synthesis attenuation, while the responsible signaling pathways could differ based on the origin of the OXPHOS defect.
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Affiliation(s)
- Kristýna Čunátová
- Laboratory of Bioenergetics, Institute of Physiology, Czech Academy of Sciences, 14200 Prague, Czech Republic
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
- Veneto Institute of Molecular Medicine, 35129 Padova, Italy
| | - Marek Vrbacký
- Laboratory of Bioenergetics, Institute of Physiology, Czech Academy of Sciences, 14200 Prague, Czech Republic
| | - Guillermo Puertas-Frias
- Laboratory of Bioenergetics, Institute of Physiology, Czech Academy of Sciences, 14200 Prague, Czech Republic
- Department of Genetics and Microbiology, Faculty of Science, Charles University, 12800 Prague, Czech Republic
| | - Lukáš Alán
- Laboratory of Bioenergetics, Institute of Physiology, Czech Academy of Sciences, 14200 Prague, Czech Republic
| | - Marie Vanišová
- Laboratory for Study of Mitochondrial Disorders, First Faculty of Medicine, Charles University and General University Hospital, 12808 Prague, Czech Republic
| | - María José Saucedo-Rodríguez
- Laboratory of Bioenergetics, Institute of Physiology, Czech Academy of Sciences, 14200 Prague, Czech Republic
- Department of Cell Biology, Faculty of Science, Charles University, 12800 Prague, Czech Republic
| | - Josef Houštěk
- Laboratory of Bioenergetics, Institute of Physiology, Czech Academy of Sciences, 14200 Prague, Czech Republic
| | - Erika Fernández-Vizarra
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
- Veneto Institute of Molecular Medicine, 35129 Padova, Italy
| | - Jiří Neužil
- School of Pharmacy and Medical Science, Griffith University, Southport, Qld 4222, Australia
- Laboratory of Molecular Therapy, Institute of Biotechnology, Czech Academy of Sciences, 25250 Prague, Czech Republic
- Department of Pediatrics and Inherited Diseases, First Faculty of Medicine, Charles University, 12108 Prague, Czech Republic
- Department of Physiology, Faculty of Science, Charles University, 12800 Prague, Czech Republic
| | - Alena Pecinová
- Laboratory of Bioenergetics, Institute of Physiology, Czech Academy of Sciences, 14200 Prague, Czech Republic
| | - Petr Pecina
- Laboratory of Bioenergetics, Institute of Physiology, Czech Academy of Sciences, 14200 Prague, Czech Republic
| | - Tomáš Mráček
- Laboratory of Bioenergetics, Institute of Physiology, Czech Academy of Sciences, 14200 Prague, Czech Republic
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Ahator SD, Hegstad K, Lentz CS, Johannessen M. Deciphering Staphylococcus aureus-host dynamics using dual activity-based protein profiling of ATP-interacting proteins. mSystems 2024; 9:e0017924. [PMID: 38656122 PMCID: PMC11097646 DOI: 10.1128/msystems.00179-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Accepted: 03/26/2024] [Indexed: 04/26/2024] Open
Abstract
The utilization of ATP within cells plays a fundamental role in cellular processes that are essential for the regulation of host-pathogen dynamics and the subsequent immune response. This study focuses on ATP-binding proteins to dissect the complex interplay between Staphylococcus aureus and human cells, particularly macrophages (THP-1) and keratinocytes (HaCaT), during an intracellular infection. A snapshot of the various protein activity and function is provided using a desthiobiotin-ATP probe, which targets ATP-interacting proteins. In S. aureus, we observe enrichment in pathways required for nutrient acquisition, biosynthesis and metabolism of amino acids, and energy metabolism when located inside human cells. Additionally, the direct profiling of the protein activity revealed specific adaptations of S. aureus to the keratinocytes and macrophages. Mapping the differentially activated proteins to biochemical pathways in the human cells with intracellular bacteria revealed cell-type-specific adaptations to bacterial challenges where THP-1 cells prioritized immune defenses, autophagic cell death, and inflammation. In contrast, HaCaT cells emphasized barrier integrity and immune activation. We also observe bacterial modulation of host processes and metabolic shifts. These findings offer valuable insights into the dynamics of S. aureus-host cell interactions, shedding light on modulating host immune responses to S. aureus, which could involve developing immunomodulatory therapies. IMPORTANCE This study uses a chemoproteomic approach to target active ATP-interacting proteins and examines the dynamic proteomic interactions between Staphylococcus aureus and human cell lines THP-1 and HaCaT. It uncovers the distinct responses of macrophages and keratinocytes during bacterial infection. S. aureus demonstrated a tailored response to the intracellular environment of each cell type and adaptation during exposure to professional and non-professional phagocytes. It also highlights strategies employed by S. aureus to persist within host cells. This study offers significant insights into the human cell response to S. aureus infection, illuminating the complex proteomic shifts that underlie the defense mechanisms of macrophages and keratinocytes. Notably, the study underscores the nuanced interplay between the host's metabolic reprogramming and immune strategy, suggesting potential therapeutic targets for enhancing host defense and inhibiting bacterial survival. The findings enhance our understanding of host-pathogen interactions and can inform the development of targeted therapies against S. aureus infections.
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Affiliation(s)
- Stephen Dela Ahator
- Centre for New Antibacterial Strategies (CANS) & Research Group for Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT–The Arctic University of Norway, Tromsø, Norway
| | - Kristin Hegstad
- Centre for New Antibacterial Strategies (CANS) & Research Group for Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT–The Arctic University of Norway, Tromsø, Norway
- Norwegian National Advisory Unit on Detection of Antimicrobial Resistance, Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway
| | - Christian S. Lentz
- Centre for New Antibacterial Strategies (CANS) & Research Group for Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT–The Arctic University of Norway, Tromsø, Norway
| | - Mona Johannessen
- Centre for New Antibacterial Strategies (CANS) & Research Group for Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT–The Arctic University of Norway, Tromsø, Norway
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3
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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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Jung SJ, Sridhara S, Ott M. Early steps in the biogenesis of mitochondrially encoded oxidative phosphorylation subunits. IUBMB Life 2024; 76:125-139. [PMID: 37712772 DOI: 10.1002/iub.2784] [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: 06/19/2023] [Accepted: 08/10/2023] [Indexed: 09/16/2023]
Abstract
The complexes mediating oxidative phosphorylation (OXPHOS) in the inner mitochondrial membrane consist of proteins encoded in the nuclear or the mitochondrial DNA. The mitochondrially encoded membrane proteins (mito-MPs) represent the catalytic core of these complexes and follow complicated pathways for biogenesis. Owing to their overall hydrophobicity, mito-MPs are co-translationally inserted into the inner membrane by the Oxa1 insertase. After insertion, OXPHOS biogenesis factors mediate the assembly of mito-MPs into complexes and participate in the regulation of mitochondrial translation, while protein quality control factors recognize and degrade faulty or excess proteins. This review summarizes the current understanding of these early steps occurring during the assembly of mito-MPs by concentrating on results obtained in the model organism baker's yeast.
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Affiliation(s)
- Sung-Jun Jung
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Sagar Sridhara
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Martin Ott
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
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Thind S, Lima D, Booy E, Trinh D, McKenna SA, Kuss S. Cytochrome c oxidase deficiency detection in human fibroblasts using scanning electrochemical microscopy. Proc Natl Acad Sci U S A 2024; 121:e2310288120. [PMID: 38154062 PMCID: PMC10769844 DOI: 10.1073/pnas.2310288120] [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: 06/20/2023] [Accepted: 11/17/2023] [Indexed: 12/30/2023] Open
Abstract
Cytochrome c oxidase deficiency (COXD) is an inherited disorder characterized by the absence or mutation in the genes encoding for the cytochrome c oxidase protein (COX). COX deficiency results in severe muscle weakness, heart, liver, and kidney disorders, as well as brain damage in infants and adolescents, leading to death in many cases. With no cure for this disorder, finding an efficient, inexpensive, and early means of diagnosis is essential to minimize symptoms and long-term disabilities. Furthermore, muscle biopsy, the traditional detection method, is invasive, expensive, and time-consuming. This study demonstrates the applicability of scanning electrochemical microscopy to quantify COX activity in living human fibroblast cells. Taking advantage of the interaction between the redox mediator N, N, N', N'-tetramethyl-para-phenylene-diamine, and COX, the enzymatic activity was successfully quantified by monitoring current changes using a platinum microelectrode and determining the apparent heterogeneous rate constant k0 using numerical modeling. This study provides a foundation for developing a diagnostic method for detecting COXD in infants, which has the potential to increase treatment effectiveness and improve the quality of life of affected individuals.
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Affiliation(s)
- Shubhneet Thind
- Laboratory for Bioanalytics and Electrochemical Sensing, Department of Chemistry, University of Manitoba, Winnipeg, MBR3T 2N2, Canada
| | - Dhésmon Lima
- Laboratory for Bioanalytics and Electrochemical Sensing, Department of Chemistry, University of Manitoba, Winnipeg, MBR3T 2N2, Canada
| | - Evan Booy
- Department of Chemistry, University of Manitoba, Winnipeg, MBR3T 2N2, Canada
| | - Dao Trinh
- Laboratoire des Sciences de l’Ingénieur Pour l’Environnement, UMR CNRS 7356, Université de La Rochelle, Pôle Sciences et Technologie17042, La Rochelle, Cedex 1, France
| | - Sean A. McKenna
- Department of Chemistry, University of Manitoba, Winnipeg, MBR3T 2N2, Canada
| | - Sabine Kuss
- Laboratory for Bioanalytics and Electrochemical Sensing, Department of Chemistry, University of Manitoba, Winnipeg, MBR3T 2N2, Canada
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Key J, Gispert S, Koepf G, Steinhoff-Wagner J, Reichlmeir M, Auburger G. Translation Fidelity and Respiration Deficits in CLPP-Deficient Tissues: Mechanistic Insights from Mitochondrial Complexome Profiling. Int J Mol Sci 2023; 24:17503. [PMID: 38139332 PMCID: PMC10743472 DOI: 10.3390/ijms242417503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/07/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023] Open
Abstract
The mitochondrial matrix peptidase CLPP is crucial during cell stress. Its loss causes Perrault syndrome type 3 (PRLTS3) with infertility, neurodegeneration, and a growth deficit. Its target proteins are disaggregated by CLPX, which also regulates heme biosynthesis via unfolding ALAS enzymes, providing access for pyridoxal-5'-phosphate (PLP). Despite efforts in diverse organisms with multiple techniques, CLPXP substrates remain controversial. Here, avoiding recombinant overexpression, we employed complexomics in mitochondria from three mouse tissues to identify endogenous targets. A CLPP absence caused the accumulation and dispersion of CLPX-VWA8 as AAA+ unfoldases, and of PLPBP. Similar changes and CLPX-VWA8 co-migration were evident for mitoribosomal central protuberance clusters, translation factors like GFM1-HARS2, the RNA granule components LRPPRC-SLIRP, and enzymes OAT-ALDH18A1. Mitochondrially translated proteins in testes showed reductions to <30% for MTCO1-3, the mis-assembly of the complex IV supercomplex, and accumulated metal-binding assembly factors COX15-SFXN4. Indeed, heavy metal levels were increased for iron, molybdenum, cobalt, and manganese. RT-qPCR showed compensatory downregulation only for Clpx mRNA; most accumulated proteins appeared transcriptionally upregulated. Immunoblots validated VWA8, MRPL38, MRPL18, GFM1, and OAT accumulation. Co-immunoprecipitation confirmed CLPX binding to MRPL38, GFM1, and OAT, so excess CLPX and PLP may affect their activity. Our data mechanistically elucidate the mitochondrial translation fidelity deficits which underlie progressive hearing impairment in PRLTS3.
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Affiliation(s)
- Jana Key
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Exp. Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (S.G.); (M.R.); (G.A.)
| | - Suzana Gispert
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Exp. Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (S.G.); (M.R.); (G.A.)
| | - Gabriele Koepf
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Exp. Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (S.G.); (M.R.); (G.A.)
| | - Julia Steinhoff-Wagner
- TUM School of Life Sciences, Animal Nutrition and Metabolism, Technical University of Munich, Liesel-Beckmann-Str. 2, 85354 Freising-Weihenstephan, Germany;
| | - Marina Reichlmeir
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Exp. Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (S.G.); (M.R.); (G.A.)
| | - Georg Auburger
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Exp. Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (S.G.); (M.R.); (G.A.)
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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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Rivett ED, Addis HG, Dietz JV, Carroll-Deaton JA, Gupta S, Foreman KL, Dang MA, Fox JL, Khalimonchuk O, Hegg EL. Evidence that the catalytic mechanism of heme a synthase involves the formation of a carbocation stabilized by a conserved glutamate. Arch Biochem Biophys 2023; 744:109665. [PMID: 37348627 PMCID: PMC10529832 DOI: 10.1016/j.abb.2023.109665] [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: 06/05/2023] [Accepted: 06/07/2023] [Indexed: 06/24/2023]
Abstract
In eukaryotes and many aerobic prokaryotes, the final step of aerobic respiration is catalyzed by an aa3-type cytochrome c oxidase, which requires a modified heme cofactor, heme a. The conversion of heme b, the prototypical cellular heme, to heme o and ultimately to heme a requires two modifications, the latter of which is conversion of a methyl group to an aldehyde, catalyzed by heme a synthase (HAS). The N- and C-terminal halves of HAS share homology, and each half contains a heme-binding site. Previous reports indicate that the C-terminal site is occupied by a heme b cofactor. The N-terminal site may function as the substrate (heme o) binding site, although this has not been confirmed experimentally. Here, we assess the role of conserved residues from the N- and C-terminal heme-binding sites in HAS from prokaryotic (Shewanella oneidensis) and eukaryotic (Saccharomyces cerevisiae) species - SoHAS/CtaA and ScHAS/Cox15, respectively. A glutamate within the N-terminal site is found to be critical for activity in both types of HAS, consistent with the hypothesis that a carbocation forms transiently during catalysis. In contrast, the residue occupying the analogous C-terminal position is dispensable for enzyme activity. In SoHAS, the C-terminal heme ligands are critical for stability, while in ScHAS, substitutions in either heme-binding site have little effect on global structure. In both species, in vivo accumulation of heme o requires the presence of an inactive HAS variant, highlighting a potential regulatory role for HAS in heme o biosynthesis.
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Affiliation(s)
- Elise D Rivett
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Hannah G Addis
- Department of Chemistry and Biochemistry, College of Charleston, Charleston, SC, 29424, USA
| | - Jonathan V Dietz
- Department of Biochemistry, University of Nebraska, Lincoln, NE, 68588, USA
| | - Jayda A Carroll-Deaton
- Department of Chemistry and Biochemistry, College of Charleston, Charleston, SC, 29424, USA
| | - Shipra Gupta
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Koji L Foreman
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Minh Anh Dang
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Jennifer L Fox
- Department of Chemistry and Biochemistry, College of Charleston, Charleston, SC, 29424, USA.
| | - Oleh Khalimonchuk
- Department of Biochemistry, University of Nebraska, Lincoln, NE, 68588, USA; Nebraska Redox Biology Center, University of Nebraska, Lincoln, NE, 68588, USA; Fred & Pamela Buffett Cancer Center, Omaha, NE, 68198, USA.
| | - Eric L Hegg
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA.
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Abstract
Leigh syndrome, or subacute necrotizing encephalomyelopathy, was initially recognized as a neuropathological entity in 1951. Bilateral symmetrical lesions, typically extending from the basal ganglia and thalamus through brainstem structures to the posterior columns of the spinal cord, are characterized microscopically by capillary proliferation, gliosis, severe neuronal loss, and relative preservation of astrocytes. Leigh syndrome is a pan-ethnic disorder usually with onset in infancy or early childhood, but late-onset forms occur, including in adult life. Over the last six decades it has emerged that this complex neurodegenerative disorder encompasses more than 100 separate monogenic disorders associated with enormous clinical and biochemical heterogeneity. This chapter discusses clinical, biochemical and neuropathological aspects of the disorder, and postulated pathomechanisms. Known genetic causes, including defects of 16 mitochondrial DNA (mtDNA) genes and approaching 100 nuclear genes, are categorized into disorders of subunits and assembly factors of the five oxidative phosphorylation enzymes, disorders of pyruvate metabolism and vitamin and cofactor transport and metabolism, disorders of mtDNA maintenance, and defects of mitochondrial gene expression, protein quality control, lipid remodeling, dynamics, and toxicity. An approach to diagnosis is presented, together with known treatable causes and an overview of current supportive management options and emerging therapies on the horizon.
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Affiliation(s)
- Shamima Rahman
- Genetics and Genomic Medicine Department, UCL Great Ormond Street Institute of Child Health, London, United Kingdom; Metabolic Medicine Department, Great Ormond Street Hospital for Children, London, United Kingdom.
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10
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Obi CD, Dailey HA, Jami-Alahmadi Y, Wohlschlegel JA, Medlock AE. Proteomic Analysis of Ferrochelatase Interactome in Erythroid and Non-Erythroid Cells. Life (Basel) 2023; 13:577. [PMID: 36836934 PMCID: PMC9958551 DOI: 10.3390/life13020577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 01/24/2023] [Accepted: 02/13/2023] [Indexed: 02/22/2023] Open
Abstract
Heme is an essential cofactor for multiple cellular processes in most organisms. In developing erythroid cells, the demand for heme synthesis is high, but is significantly lower in non-erythroid cells. While the biosynthesis of heme in metazoans is well understood, the tissue-specific regulation of the pathway is less explored. To better understand this, we analyzed the mitochondrial heme metabolon in erythroid and non-erythroid cell lines from the perspective of ferrochelatase (FECH), the terminal enzyme in the heme biosynthetic pathway. Affinity purification of FLAG-tagged-FECH, together with mass spectrometric analysis, was carried out to identify putative protein partners in human and murine cell lines. Proteins involved in the heme biosynthetic process and mitochondrial organization were identified as the core components of the FECH interactome. Interestingly, in non-erythroid cell lines, the FECH interactome is highly enriched with proteins associated with the tricarboxylic acid (TCA) cycle. Overall, our study shows that the mitochondrial heme metabolon in erythroid and non-erythroid cells has similarities and differences, and suggests new roles for the mitochondrial heme metabolon and heme in regulating metabolic flux and key cellular processes.
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Affiliation(s)
- Chibuike David Obi
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Harry A. Dailey
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
| | - Yasaman Jami-Alahmadi
- Department of Biological Chemistry, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - James A. Wohlschlegel
- Department of Biological Chemistry, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Amy E. Medlock
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
- Augusta University/University of Georgia Medical Partnership, Athens, GA 30606, USA
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11
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Schulz V, Basu S, Freibert SA, Webert H, Boss L, Mühlenhoff U, Pierrel F, Essen LO, Warui DM, Booker SJ, Stehling O, Lill R. Functional spectrum and specificity of mitochondrial ferredoxins FDX1 and FDX2. Nat Chem Biol 2023; 19:206-217. [PMID: 36280795 PMCID: PMC10873809 DOI: 10.1038/s41589-022-01159-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 09/01/2022] [Indexed: 02/04/2023]
Abstract
Ferredoxins comprise a large family of iron-sulfur (Fe-S) proteins that shuttle electrons in diverse biological processes. Human mitochondria contain two isoforms of [2Fe-2S] ferredoxins, FDX1 (aka adrenodoxin) and FDX2, with known functions in cytochrome P450-dependent steroid transformations and Fe-S protein biogenesis. Here, we show that only FDX2, but not FDX1, is involved in Fe-S protein maturation. Vice versa, FDX1 is specific not only for steroidogenesis, but also for heme a and lipoyl cofactor biosyntheses. In the latter pathway, FDX1 provides electrons to kickstart the radical chain reaction catalyzed by lipoyl synthase. We also identified lipoylation as a target of the toxic antitumor copper ionophore elesclomol. Finally, the striking target specificity of each ferredoxin was assigned to small conserved sequence motifs. Swapping these motifs changed the target specificity of these electron donors. Together, our findings identify new biochemical tasks of mitochondrial ferredoxins and provide structural insights into their functional specificity.
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Affiliation(s)
- Vinzent Schulz
- Institute for Cytobiology, Philipps University of Marburg, Marburg, Germany
| | - Somsuvro Basu
- Institute for Cytobiology, Philipps University of Marburg, Marburg, Germany
- Freelance Medical Communications Consultant, Brno, Czech Republic
| | - Sven-A Freibert
- Institute for Cytobiology, Philipps University of Marburg, Marburg, Germany
| | - Holger Webert
- Institute for Cytobiology, Philipps University of Marburg, Marburg, Germany
| | - Linda Boss
- Institute for Cytobiology, Philipps University of Marburg, Marburg, Germany
| | - Ulrich Mühlenhoff
- Institute for Cytobiology, Philipps University of Marburg, Marburg, Germany
| | - Fabien Pierrel
- Univ. of Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, Grenoble, France
| | - Lars-O Essen
- Department of Biochemistry, Faculty of Chemistry, Philipps University of Marburg, Marburg, Germany
| | - Douglas M Warui
- Department of Chemistry, The Pennsylvania State University, University Park, PA, USA
| | - Squire J Booker
- Department of Chemistry, The Pennsylvania State University, University Park, PA, USA
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
- The Howard Hughes Medical Institute, The Pennsylvania State University, University Park, PA, USA
| | - Oliver Stehling
- Institute for Cytobiology, Philipps University of Marburg, Marburg, Germany.
- Centre for Synthetic Microbiology, Synmikro, Marburg, Germany.
| | - Roland Lill
- Institute for Cytobiology, Philipps University of Marburg, Marburg, Germany.
- Centre for Synthetic Microbiology, Synmikro, Marburg, Germany.
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12
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Protein Transduction Domain-Mediated Delivery of Recombinant Proteins and In Vitro Transcribed mRNAs for Protein Replacement Therapy of Human Severe Genetic Mitochondrial Disorders: The Case of Sco2 Deficiency. Pharmaceutics 2023; 15:pharmaceutics15010286. [PMID: 36678915 PMCID: PMC9861957 DOI: 10.3390/pharmaceutics15010286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/31/2022] [Accepted: 01/09/2023] [Indexed: 01/19/2023] Open
Abstract
Mitochondrial disorders represent a heterogeneous group of genetic disorders with variations in severity and clinical outcomes, mostly characterized by respiratory chain dysfunction and abnormal mitochondrial function. More specifically, mutations in the human SCO2 gene, encoding the mitochondrial inner membrane Sco2 cytochrome c oxidase (COX) assembly protein, have been implicated in the mitochondrial disorder fatal infantile cardioencephalomyopathy with COX deficiency. Since an effective treatment is still missing, a protein replacement therapy (PRT) was explored using protein transduction domain (PTD) technology. Therefore, the human recombinant full-length mitochondrial protein Sco2, fused to TAT peptide (a common PTD), was produced (fusion Sco2 protein) and successfully transduced into fibroblasts derived from a SCO2/COX-deficient patient. This PRT contributed to effective COX assembly and partial recovery of COX activity. In mice, radiolabeled fusion Sco2 protein was biodistributed in the peripheral tissues of mice and successfully delivered into their mitochondria. Complementary to that, an mRNA-based therapeutic approach has been more recently considered as an innovative treatment option. In particular, a patented, novel PTD-mediated IVT-mRNA delivery platform was developed and applied in recent research efforts. PTD-IVT-mRNA of full-length SCO2 was successfully transduced into the fibroblasts derived from a SCO2/COX-deficient patient, translated in host ribosomes into a nascent chain of human Sco2, imported into mitochondria, and processed to the mature protein. Consequently, the recovery of reduced COX activity was achieved, thus suggesting the potential of this mRNA-based technology for clinical translation as a PRT for metabolic/genetic disorders. In this review, such research efforts will be comprehensibly presented and discussed to elaborate their potential in clinical application and therapeutic usefulness.
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13
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Mitochondrial Fission Process 1 controls inner membrane integrity and protects against heart failure. Nat Commun 2022; 13:6634. [PMID: 36333300 PMCID: PMC9636241 DOI: 10.1038/s41467-022-34316-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 10/21/2022] [Indexed: 11/06/2022] Open
Abstract
Mitochondria are paramount to the metabolism and survival of cardiomyocytes. Here we show that Mitochondrial Fission Process 1 (MTFP1) is an inner mitochondrial membrane (IMM) protein that is dispensable for mitochondrial division yet essential for cardiac structure and function. Constitutive knockout of cardiomyocyte MTFP1 in mice resulted in a fatal, adult-onset dilated cardiomyopathy accompanied by extensive mitochondrial and cardiac remodeling during the transition to heart failure. Prior to the onset of disease, knockout cardiac mitochondria displayed specific IMM defects: futile proton leak dependent upon the adenine nucleotide translocase and an increased sensitivity to the opening of the mitochondrial permeability transition pore, with which MTFP1 physically and genetically interacts. Collectively, our data reveal new functions of MTFP1 in the control of bioenergetic efficiency and cell death sensitivity and define its importance in preventing pathogenic cardiac remodeling.
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14
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Li L, Chen M, Liu W, Tai P, Liu X, Liu JX. Zebrafish cox17 modulates primitive erythropoiesis via regulation of mitochondrial metabolism to facilitate hypoxia tolerance. FASEB J 2022; 36:e22596. [PMID: 36208295 DOI: 10.1096/fj.202200829r] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 08/31/2022] [Accepted: 09/26/2022] [Indexed: 11/11/2022]
Abstract
Cox17 is required in the assembly of mitochondrial intermembrane space (IMS) and Cu metallization of cytochrome C oxidase (CcO) in mitochondria as well as Cu homeostasis in cells. Cox deficiency is associated with hematopoietic diseases such as tubulopathy and leukodystrophy, but whether and how cox17 functions in hematopoiesis are still unknown. Here, we report the effects of zebrafish cox17 deficiency on primitive erythropoiesis, mitochondrial metabolism, and hypoxia tolerance. Cox17-/- larvae were sensitive to hypoxia stress, with reduced primitive erythropoiesis. Meanwhile, cox17-/- mutants showed a significant reduction in the expression of pivotal transcriptional regulators in erythropoiesis, such as scl, lmo2, and gata1a at 14 h post fertilization (hpf), with expression remaining downregulated for scl but upregulated for lmo2 and gata1a at 24 hpf. Mechanistically, cox17-/- mutants showed impaired mitochondrial metabolism, coupled with a significant decrease in the mitochondrial membrane potential, ATP and SAM content, and the ratio of SAM and SAH. Additionally, disrupting mitochondrial metabolism in wild type (WT) larvae treated with carbonyl cyanide 3-chlorophenylhydrazone (CCCP) could mimic the primitive erythropoiesis defects observed in cox17-/- mutants. Moreover, cox17-/- mutants exhibited significantly downregulated WNT signaling and upregulated ER stress, with a significant reduction of beta-Catenin in gata1a+ cells and of binding enrichment in both scl and lmo2 promoters of the WNT transcriptional factor TCF4. This is the first report on the novel linkage of cox17 deficiency with defective primitive erythropoiesis and reduced hypoxia tolerance. This study has shed light on the potential mechanism by which Cox deficiency, especially cox17 deficiency, induces Cu homeostasis imbalance, leading to hematopoietic diseases.
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Affiliation(s)
- LingYa Li
- College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, China
| | - MingYue Chen
- College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, China
| | - WenYe Liu
- College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, China
| | - PengZhi Tai
- College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, China
| | - Xingguo Liu
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Science, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Science; Guangzhou Medical University, Guangzhou, China
| | - Jing-Xia Liu
- College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, China
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15
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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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16
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Deletion of cox7c Results in Pan-Azole Resistance in Aspergillus fumigatus. Antimicrob Agents Chemother 2022; 66:e0015122. [PMID: 35647650 PMCID: PMC9211413 DOI: 10.1128/aac.00151-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Aspergillus fumigatus, the most prevalent resistance to azoles results from mutational modifications of the azole target protein Cyp51A, but there are non-cyp51A mutants resistant to azoles, and the mechanisms underlying the resistance of these strains remain to be explored. Here, we identified a novel cytochrome c oxidase, cox7c (W56*), nonsense mutation in the laboratory and found that it caused reduced colony growth and resistance to multiantifungal agents. Meanwhile, we revealed that cold storage is responsible for increased tolerance of conidia to itraconazole (ITC) stress, which further advances azole-resistant mutations (cryopreservation→ITC tolerance→azole resistance). The deletion or mutation of cox7c results explicitly in resistance to antifungal-targeting enzymes, including triazoles, polyenes, and allylamines, required for ergosterol synthesis, or resistance to fungal ergosterol. A high-performance liquid chromatography (HPLC) assay showed that the cox7c knockout strain decreased intracellular itraconazole concentration. In addition, the lack of Cox7c resulted in the accumulation of intracellular heme B. We validated that an endogenous increase in, or the exogenous addition of, heme B was capable of eliciting azole resistance, which was in good accordance with the phenotypic resistance analysis of cox7c mutants. Furthermore, RNA sequencing verified the elevated transcriptional expression levels of multidrug transport genes. Additionally, lower itraconazole-induced reactive oxygen species generation in mycelia of a cox7c-deletion strain suggested that this reduction may, in part, contribute to drug resistance. These findings increase our understanding of how A. fumigatus’s direct responses to azoles promote fungal survival in the environment and address genetic mutations that arise from patients or environments.
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17
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Mitochondrial Neurodegeneration. Cells 2022; 11:cells11040637. [PMID: 35203288 PMCID: PMC8870525 DOI: 10.3390/cells11040637] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 01/28/2022] [Accepted: 02/06/2022] [Indexed: 01/27/2023] Open
Abstract
Mitochondria are cytoplasmic organelles, which generate energy as heat and ATP, the universal energy currency of the cell. This process is carried out by coupling electron stripping through oxidation of nutrient substrates with the formation of a proton-based electrochemical gradient across the inner mitochondrial membrane. Controlled dissipation of the gradient can lead to production of heat as well as ATP, via ADP phosphorylation. This process is known as oxidative phosphorylation, and is carried out by four multiheteromeric complexes (from I to IV) of the mitochondrial respiratory chain, carrying out the electron flow whose energy is stored as a proton-based electrochemical gradient. This gradient sustains a second reaction, operated by the mitochondrial ATP synthase, or complex V, which condensates ADP and Pi into ATP. Four complexes (CI, CIII, CIV, and CV) are composed of proteins encoded by genes present in two separate compartments: the nuclear genome and a small circular DNA found in mitochondria themselves, and are termed mitochondrial DNA (mtDNA). Mutations striking either genome can lead to mitochondrial impairment, determining infantile, childhood or adult neurodegeneration. Mitochondrial disorders are complex neurological syndromes, and are often part of a multisystem disorder. In this paper, we divide the diseases into those caused by mtDNA defects and those that are due to mutations involving nuclear genes; from a clinical point of view, we discuss pediatric disorders in comparison to juvenile or adult-onset conditions. The complementary genetic contributions controlling organellar function and the complexity of the biochemical pathways present in the mitochondria justify the extreme genetic and phenotypic heterogeneity of this new area of inborn errors of metabolism known as ‘mitochondrial medicine’.
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18
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Sun H, Mertz RW, Smith LB, Scott JG. Transcriptomic and proteomic analysis of pyrethroid resistance in the CKR strain of Aedes aegypti. PLoS Negl Trop Dis 2021; 15:e0009871. [PMID: 34723971 PMCID: PMC8559961 DOI: 10.1371/journal.pntd.0009871] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 10/04/2021] [Indexed: 12/13/2022] Open
Abstract
Aedes aegypti is an important vector of human viral diseases. This mosquito is distributed globally and thrives in urban environments, making it a serious risk to human health. Pyrethroid insecticides have been the mainstay for control of adult A. aegypti for decades, but resistance has evolved, making control problematic in some areas. One major mechanism of pyrethroid resistance is detoxification by cytochrome P450 monooxygenases (CYPs), commonly associated with the overexpression of one or more CYPs. Unfortunately, the molecular basis underlying this mechanism remains unknown. We used a combination of RNA-seq and proteomic analysis to evaluate the molecular basis of pyrethroid resistance in the highly resistant CKR strain of A. aegypti. The CKR strain has the resistance mechanisms from the well-studied Singapore (SP) strain introgressed into the susceptible Rockefeller (ROCK) strain genome. The RNA-seq and proteomics data were complimentary; each offering insights that the other technique did not provide. However, transcriptomic results did not quantitatively mirror results of the proteomics. There were 10 CYPs which had increased expression of both transcripts and proteins. These CYPs appeared to be largely trans-regulated, except for some CYPs for which we could not rule out gene duplication. We identified 65 genes and lncRNAs as potentially being responsible for elevating the expression of CYPs in CKR. Resistance was associated with multiple loci on chromosome 1 and at least one locus on chromosome 3. We also identified five CYPs that were overexpressed only as proteins, suggesting that stabilization of CYP proteins could be a mechanism of resistance. Future studies to increase the resolution of the resistance loci, and to examine the candidate genes and lncRNAs identified here will greatly enhance our understanding of CYP-mediated resistance in A. aegypti.
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Affiliation(s)
- Haina Sun
- School of Basic Medicine and Biological Sciences, Soochow University, Suzhou, Jiangsu China
- Department of Entomology, Comstock Hall, Cornell University, Ithaca, New York, United States of America
| | - Robert W. Mertz
- Department of Entomology, Comstock Hall, Cornell University, Ithaca, New York, United States of America
| | - Letícia B. Smith
- Department of Entomology, Comstock Hall, Cornell University, Ithaca, New York, United States of America
- Laboratory of Malaria and Vector Research, NIAID, National Institutes of Health, Rockville, Maryland, United States of America
| | - Jeffrey G. Scott
- Department of Entomology, Comstock Hall, Cornell University, Ithaca, New York, United States of America
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19
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Stokum JA, Shim B, Huang W, Kane M, Smith JA, Gerzanich V, Simard JM. A large portion of the astrocyte proteome is dedicated to perivascular endfeet, including critical components of the electron transport chain. J Cereb Blood Flow Metab 2021; 41:2546-2560. [PMID: 33818185 PMCID: PMC8504955 DOI: 10.1177/0271678x211004182] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The perivascular astrocyte endfoot is a specialized and diffusion-limited subcellular compartment that fully ensheathes the cerebral vasculature. Despite their ubiquitous presence, a detailed understanding of endfoot physiology remains elusive, in part due to a limited understanding of the proteins that distinguish the endfoot from the greater astrocyte body. Here, we developed a technique to isolate astrocyte endfeet from brain tissue, which was used to study the endfoot proteome in comparison to the astrocyte somata. In our approach, brain microvessels, which retain their endfoot processes, were isolated from mouse brain and dissociated, whereupon endfeet were recovered using an antibody-based column astrocyte isolation kit. Our findings expand the known set of proteins enriched at the endfoot from 10 to 516, which comprised more than 1/5th of the entire detected astrocyte proteome. Numerous critical electron transport chain proteins were expressed only at the endfeet, while enzymes involved in glycogen storage were distributed to the somata, indicating subcellular metabolic compartmentalization. The endfoot proteome also included numerous proteins that, while known to have important contributions to blood-brain barrier function, were not previously known to localize to the endfoot. Our findings highlight the importance of the endfoot and suggest new routes of investigation into endfoot function.
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Affiliation(s)
- Jesse A Stokum
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Bosung Shim
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Weiliang Huang
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, MD, USA
| | - Maureen Kane
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, MD, USA
| | - Jesse A Smith
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Volodymyr Gerzanich
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - J Marc Simard
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD, USA.,Department of Pathology, University of Maryland School of Medicine, Baltimore, MD, USA.,Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA
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20
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Rivett ED, Heo L, Feig M, Hegg EL. Biosynthesis and trafficking of heme o and heme a: new structural insights and their implications for reaction mechanisms and prenylated heme transfer. Crit Rev Biochem Mol Biol 2021; 56:640-668. [PMID: 34428995 DOI: 10.1080/10409238.2021.1957668] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Aerobic respiration is a key energy-producing pathway in many prokaryotes and virtually all eukaryotes. The final step of aerobic respiration is most commonly catalyzed by heme-copper oxidases embedded in the cytoplasmic or mitochondrial membrane. The majority of these terminal oxidases contain a prenylated heme (typically heme a or occasionally heme o) in the active site. In addition, many heme-copper oxidases, including mitochondrial cytochrome c oxidases, possess a second heme a cofactor. Despite the critical role of heme a in the electron transport chain, the details of the mechanism by which heme b, the prototypical cellular heme, is converted to heme o and then to heme a remain poorly understood. Recent structural investigations, however, have helped clarify some elements of heme a biosynthesis. In this review, we discuss the insight gained from these advances. In particular, we present a new structural model of heme o synthase (HOS) based on distance restraints from inferred coevolutionary relationships and refined by molecular dynamics simulations that are in good agreement with the experimentally determined structures of HOS homologs. We also analyze the two structures of heme a synthase (HAS) that have recently been solved by other groups. For both HOS and HAS, we discuss the proposed catalytic mechanisms and highlight how new insights into the heme-binding site locations shed light on previously obtained biochemical data. Finally, we explore the implications of the new structural data in the broader context of heme trafficking in the heme a biosynthetic pathway and heme-copper oxidase assembly.
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Affiliation(s)
- Elise D Rivett
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Lim Heo
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Michael Feig
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Eric L Hegg
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
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21
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Dietz JV, Fox JL, Khalimonchuk O. Down the Iron Path: Mitochondrial Iron Homeostasis and Beyond. Cells 2021; 10:cells10092198. [PMID: 34571846 PMCID: PMC8468894 DOI: 10.3390/cells10092198] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 08/22/2021] [Accepted: 08/23/2021] [Indexed: 12/20/2022] Open
Abstract
Cellular iron homeostasis and mitochondrial iron homeostasis are interdependent. Mitochondria must import iron to form iron–sulfur clusters and heme, and to incorporate these cofactors along with iron ions into mitochondrial proteins that support essential functions, including cellular respiration. In turn, mitochondria supply the cell with heme and enable the biogenesis of cytosolic and nuclear proteins containing iron–sulfur clusters. Impairment in cellular or mitochondrial iron homeostasis is deleterious and can result in numerous human diseases. Due to its reactivity, iron is stored and trafficked through the body, intracellularly, and within mitochondria via carefully orchestrated processes. Here, we focus on describing the processes of and components involved in mitochondrial iron trafficking and storage, as well as mitochondrial iron–sulfur cluster biogenesis and heme biosynthesis. Recent findings and the most pressing topics for future research are highlighted.
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Affiliation(s)
- Jonathan V. Dietz
- Department of Biochemistry, University of Nebraska, Lincoln, NE 68588, USA;
| | - Jennifer L. Fox
- Department of Chemistry and Biochemistry, College of Charleston, Charleston, SC 29424, USA;
| | - Oleh Khalimonchuk
- Department of Biochemistry, University of Nebraska, Lincoln, NE 68588, USA;
- Nebraska Redox Biology Center, University of Nebraska, Lincoln, NE 68588, USA
- Fred and Pamela Buffett Cancer Center, Omaha, NE 68198, USA
- Correspondence:
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22
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Feng Y, Huang W, Paul C, Liu X, Sadayappan S, Wang Y, Pauklin S. Mitochondrial nucleoid in cardiac homeostasis: bidirectional signaling of mitochondria and nucleus in cardiac diseases. Basic Res Cardiol 2021; 116:49. [PMID: 34392401 PMCID: PMC8364536 DOI: 10.1007/s00395-021-00889-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 07/20/2021] [Indexed: 01/11/2023]
Abstract
Metabolic function and energy production in eukaryotic cells are regulated by mitochondria, which have been recognized as the intracellular 'powerhouses' of eukaryotic cells for their regulation of cellular homeostasis. Mitochondrial function is important not only in normal developmental and physiological processes, but also in a variety of human pathologies, including cardiac diseases. An emerging topic in the field of cardiovascular medicine is the implication of mitochondrial nucleoid for metabolic reprogramming. This review describes the linear/3D architecture of the mitochondrial nucleoid (e.g., highly organized protein-DNA structure of nucleoid) and how it is regulated by a variety of factors, such as noncoding RNA and its associated R-loop, for metabolic reprogramming in cardiac diseases. In addition, we highlight many of the presently unsolved questions regarding cardiac metabolism in terms of bidirectional signaling of mitochondrial nucleoid and 3D chromatin structure in the nucleus. In particular, we explore novel techniques to dissect the 3D structure of mitochondrial nucleoid and propose new insights into the mitochondrial retrograde signaling, and how it regulates the nuclear (3D) chromatin structures in mitochondrial diseases.
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Affiliation(s)
- Yuliang Feng
- Botnar Research Centre, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Old Road, University of Oxford, Oxford, OX3 7LD, UK
| | - Wei Huang
- Department of Pathology and Laboratory Medicine, Regenerative Medicine Research, University of Cincinnati College of Medicine, 231 Albert Sabin Way, CincinnatiCincinnati, OH, 45267-0529, USA
| | - Christian Paul
- Department of Pathology and Laboratory Medicine, Regenerative Medicine Research, University of Cincinnati College of Medicine, 231 Albert Sabin Way, CincinnatiCincinnati, OH, 45267-0529, USA
| | - Xingguo Liu
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Hefei Institute of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
- Guangzhou Regenerative Medicine and Health Guangdong Laboratory, CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Hefei Institute of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Guangzhou Medical University, Guangzhou, 510530, China
- Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Institute for Stem Cell and Regeneration, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
| | - Sakthivel Sadayappan
- Heart, Lung and Vascular Institute, Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, OH, 45267, USA
| | - Yigang Wang
- Department of Pathology and Laboratory Medicine, Regenerative Medicine Research, University of Cincinnati College of Medicine, 231 Albert Sabin Way, CincinnatiCincinnati, OH, 45267-0529, USA.
| | - Siim Pauklin
- Botnar Research Centre, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Old Road, University of Oxford, Oxford, OX3 7LD, UK.
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23
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Zanfardino P, Doccini S, Santorelli FM, Petruzzella V. Tackling Dysfunction of Mitochondrial Bioenergetics in the Brain. Int J Mol Sci 2021; 22:8325. [PMID: 34361091 PMCID: PMC8348117 DOI: 10.3390/ijms22158325] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/29/2021] [Accepted: 07/30/2021] [Indexed: 12/15/2022] Open
Abstract
Oxidative phosphorylation (OxPhos) is the basic function of mitochondria, although the landscape of mitochondrial functions is continuously growing to include more aspects of cellular homeostasis. Thanks to the application of -omics technologies to the study of the OxPhos system, novel features emerge from the cataloging of novel proteins as mitochondrial thus adding details to the mitochondrial proteome and defining novel metabolic cellular interrelations, especially in the human brain. We focussed on the diversity of bioenergetics demand and different aspects of mitochondrial structure, functions, and dysfunction in the brain. Definition such as 'mitoexome', 'mitoproteome' and 'mitointeractome' have entered the field of 'mitochondrial medicine'. In this context, we reviewed several genetic defects that hamper the last step of aerobic metabolism, mostly involving the nervous tissue as one of the most prominent energy-dependent tissues and, as consequence, as a primary target of mitochondrial dysfunction. The dual genetic origin of the OxPhos complexes is one of the reasons for the complexity of the genotype-phenotype correlation when facing human diseases associated with mitochondrial defects. Such complexity clinically manifests with extremely heterogeneous symptoms, ranging from organ-specific to multisystemic dysfunction with different clinical courses. Finally, we briefly discuss the future directions of the multi-omics study of human brain disorders.
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Affiliation(s)
- Paola Zanfardino
- Department of Medical Basic Sciences, Neurosciences and Sense Organs, University of Bari Aldo Moro, 70124 Bari, Italy;
| | - Stefano Doccini
- IRCCS Fondazione Stella Maris, Calambrone, 56128 Pisa, Italy;
| | | | - Vittoria Petruzzella
- Department of Medical Basic Sciences, Neurosciences and Sense Organs, University of Bari Aldo Moro, 70124 Bari, Italy;
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24
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Galvão de Oliveira M, Tengan C, Micheletti C, Ramos de Macedo P, Soares Pinho Cernach MC, Cavole TR, de França Basto M, Filho JS, Virmond LA, Milanezi F, Nakano V, Falconi A, Perrone E. A novel variant in the COX15 gene causing a fatal infantile cardioencephalomyopathy: A case report with clinical and molecular review. Eur J Med Genet 2021; 64:104195. [PMID: 33746038 DOI: 10.1016/j.ejmg.2021.104195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 03/04/2021] [Accepted: 03/14/2021] [Indexed: 10/21/2022]
Abstract
The cytochrome c-oxidase (COX) enzyme, also known as mitochondrial complex IV (MT-C4D), is a transmembrane protein complex found in mitochondria. COX deficiency is one of the most frequent causes of electron transport chain defects in humans. Therefore, high energy demand organs and tissues are affected in patients with mutations in the COX15 gene, with variable phenotypic expressiveness. We describe the case of a male newborn with hypertrophic cardiomyopathy and serum and cerebrospinal fluid hyperlacticaemia, whose exome sequencing revealed two variants in a compound heterozygous state: c.232G > A; p.(Gly78Arg), classified as likely pathogenic, and c.452C > G; p.(Ser151Ter), as pathogenic; the former never previously described in the literature.
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Affiliation(s)
| | - Célia Tengan
- Universidade Federal de São Paulo, Unifesp, Departamento de Neurologia, São Paulo, SP, CEP 04039-000, Brazil.
| | - Cecília Micheletti
- Universidade Federal de São Paulo, Unifesp, Departamento de Pediatria, São Paulo, SP, CEP 04023-060, Brazil.
| | - Paloma Ramos de Macedo
- Universidade Federal de São Paulo, Unifesp, Departamento de Neurologia, São Paulo, SP, CEP 04039-000, Brazil.
| | | | - Thiago Rodrigues Cavole
- Universidade Federal de São Paulo, Unifesp, Departamento de Genética, São Paulo, SP, CEP 04023-061, Brazil.
| | - Marina de França Basto
- Universidade Federal de São Paulo, Unifesp, Departamento de Genética, São Paulo, SP, CEP 04023-061, Brazil.
| | - Joselito Sobreira Filho
- Universidade Federal de São Paulo, Unifesp, Departamento de Genética, São Paulo, SP, CEP 04023-061, Brazil.
| | - Luiza Amaral Virmond
- Universidade Federal de São Paulo, Unifesp, Departamento de Genética, São Paulo, SP, CEP 04023-061, Brazil.
| | | | | | | | - Eduardo Perrone
- Universidade Federal de São Paulo, Unifesp, Departamento de Genética, São Paulo, SP, CEP 04023-061, Brazil.
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25
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Blackout in the powerhouse: clinical phenotypes associated with defects in the assembly of OXPHOS complexes and the mitoribosome. Biochem J 2021; 477:4085-4132. [PMID: 33151299 PMCID: PMC7657662 DOI: 10.1042/bcj20190767] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 09/29/2020] [Accepted: 10/05/2020] [Indexed: 12/26/2022]
Abstract
Mitochondria produce the bulk of the energy used by almost all eukaryotic cells through oxidative phosphorylation (OXPHOS) which occurs on the four complexes of the respiratory chain and the F1–F0 ATPase. Mitochondrial diseases are a heterogenous group of conditions affecting OXPHOS, either directly through mutation of genes encoding subunits of OXPHOS complexes, or indirectly through mutations in genes encoding proteins supporting this process. These include proteins that promote assembly of the OXPHOS complexes, the post-translational modification of subunits, insertion of cofactors or indeed subunit synthesis. The latter is important for all 13 of the proteins encoded by human mitochondrial DNA, which are synthesised on mitochondrial ribosomes. Together the five OXPHOS complexes and the mitochondrial ribosome are comprised of more than 160 subunits and many more proteins support their biogenesis. Mutations in both nuclear and mitochondrial genes encoding these proteins have been reported to cause mitochondrial disease, many leading to defective complex assembly with the severity of the assembly defect reflecting the severity of the disease. This review aims to act as an interface between the clinical and basic research underpinning our knowledge of OXPHOS complex and ribosome assembly, and the dysfunction of this process in mitochondrial disease.
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26
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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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27
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Mitochondrial Structure and Bioenergetics in Normal and Disease Conditions. Int J Mol Sci 2021; 22:ijms22020586. [PMID: 33435522 PMCID: PMC7827222 DOI: 10.3390/ijms22020586] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/03/2021] [Accepted: 01/04/2021] [Indexed: 02/06/2023] Open
Abstract
Mitochondria are ubiquitous intracellular organelles found in almost all eukaryotes and involved in various aspects of cellular life, with a primary role in energy production. The interest in this organelle has grown stronger with the discovery of their link to various pathologies, including cancer, aging and neurodegenerative diseases. Indeed, dysfunctional mitochondria cannot provide the required energy to tissues with a high-energy demand, such as heart, brain and muscles, leading to a large spectrum of clinical phenotypes. Mitochondrial defects are at the origin of a group of clinically heterogeneous pathologies, called mitochondrial diseases, with an incidence of 1 in 5000 live births. Primary mitochondrial diseases are associated with genetic mutations both in nuclear and mitochondrial DNA (mtDNA), affecting genes involved in every aspect of the organelle function. As a consequence, it is difficult to find a common cause for mitochondrial diseases and, subsequently, to offer a precise clinical definition of the pathology. Moreover, the complexity of this condition makes it challenging to identify possible therapies or drug targets.
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28
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Fernandez-Vizarra E, Zeviani M. Mitochondrial disorders of the OXPHOS system. FEBS Lett 2020; 595:1062-1106. [PMID: 33159691 DOI: 10.1002/1873-3468.13995] [Citation(s) in RCA: 109] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 10/21/2020] [Accepted: 11/01/2020] [Indexed: 12/13/2022]
Abstract
Mitochondrial disorders are among the most frequent inborn errors of metabolism, their primary cause being the dysfunction of the oxidative phosphorylation system (OXPHOS). OXPHOS is composed of the electron transport chain (ETC), formed by four multimeric enzymes and two mobile electron carriers, plus an ATP synthase [also called complex V (cV)]. The ETC performs the redox reactions involved in cellular respiration while generating the proton motive force used by cV to synthesize ATP. OXPHOS biogenesis involves multiple steps, starting from the expression of genes encoded in physically separated genomes, namely the mitochondrial and nuclear DNA, to the coordinated assembly of components and cofactors building each individual complex and eventually the supercomplexes. The genetic cause underlying around half of the diagnosed mitochondrial disease cases is currently known. Many of these cases result from pathogenic variants in genes encoding structural subunits or additional factors directly involved in the assembly of the ETC complexes. Here, we review the historical and most recent findings concerning the clinical phenotypes and the molecular pathological mechanisms underlying this particular group of disorders.
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Affiliation(s)
- Erika Fernandez-Vizarra
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - Massimo Zeviani
- Venetian Institute of Molecular Medicine, Padova, Italy.,Department of Neurosciences, University of Padova, Italy
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29
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Human Mitochondrial Pathologies of the Respiratory Chain and ATP Synthase: Contributions from Studies of Saccharomyces cerevisiae. Life (Basel) 2020; 10:life10110304. [PMID: 33238568 PMCID: PMC7700678 DOI: 10.3390/life10110304] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 12/14/2022] Open
Abstract
The ease with which the unicellular yeast Saccharomyces cerevisiae can be manipulated genetically and biochemically has established this organism as a good model for the study of human mitochondrial diseases. The combined use of biochemical and molecular genetic tools has been instrumental in elucidating the functions of numerous yeast nuclear gene products with human homologs that affect a large number of metabolic and biological processes, including those housed in mitochondria. These include structural and catalytic subunits of enzymes and protein factors that impinge on the biogenesis of the respiratory chain. This article will review what is currently known about the genetics and clinical phenotypes of mitochondrial diseases of the respiratory chain and ATP synthase, with special emphasis on the contribution of information gained from pet mutants with mutations in nuclear genes that impair mitochondrial respiration. Our intent is to provide the yeast mitochondrial specialist with basic knowledge of human mitochondrial pathologies and the human specialist with information on how genes that directly and indirectly affect respiration were identified and characterized in yeast.
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30
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Cytochrome c oxidase deficiency. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1862:148335. [PMID: 33171185 DOI: 10.1016/j.bbabio.2020.148335] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/31/2020] [Accepted: 11/03/2020] [Indexed: 12/23/2022]
Abstract
Cytochrome c oxidase (COX) deficiency is characterized by a high degree of genetic and phenotypic heterogeneity, partly reflecting the extreme structural complexity, multiple post-translational modification, variable, tissue-specific composition, and the high number of and intricate connections among the assembly factors of this enzyme. In fact, decreased COX specific activity can manifest with different degrees of severity, affect the whole organism or specific tissues, and develop a wide spectrum of disease natural history, including disease onsets ranging from birth to late adulthood. More than 30 genes have been linked to COX deficiency, but the list is still incomplete and in fact constantly updated. We here discuss the current knowledge about COX in health and disease, focusing on genetic aetiology and link to clinical manifestations. In addition, information concerning either fundamental biological features of the enzymes or biochemical signatures of its defects have been provided by experimental in vivo models, including yeast, fly, mouse and fish, which expanded our knowledge on the functional features and the phenotypical consequences of different forms of COX deficiency.
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31
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Functions of Cytochrome c oxidase Assembly Factors. Int J Mol Sci 2020; 21:ijms21197254. [PMID: 33008142 PMCID: PMC7582755 DOI: 10.3390/ijms21197254] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 09/23/2020] [Indexed: 12/22/2022] Open
Abstract
Cytochrome c oxidase is the terminal complex of eukaryotic oxidative phosphorylation in mitochondria. This process couples the reduction of electron carriers during metabolism to the reduction of molecular oxygen to water and translocation of protons from the internal mitochondrial matrix to the inter-membrane space. The electrochemical gradient formed is used to generate chemical energy in the form of adenosine triphosphate to power vital cellular processes. Cytochrome c oxidase and most oxidative phosphorylation complexes are the product of the nuclear and mitochondrial genomes. This poses a series of topological and temporal steps that must be completed to ensure efficient assembly of the functional enzyme. Many assembly factors have evolved to perform these steps for insertion of protein into the inner mitochondrial membrane, maturation of the polypeptide, incorporation of co-factors and prosthetic groups and to regulate this process. Much of the information about each of these assembly factors has been gleaned from use of the single cell eukaryote Saccharomyces cerevisiae and also mutations responsible for human disease. This review will focus on the assembly factors of cytochrome c oxidase to highlight some of the outstanding questions in the assembly of this vital enzyme complex.
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32
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Singh AP, Salvatori R, Aftab W, Kohler A, Carlström A, Forne I, Imhof A, Ott M. Molecular Connectivity of Mitochondrial Gene Expression and OXPHOS Biogenesis. Mol Cell 2020; 79:1051-1065.e10. [PMID: 32877643 DOI: 10.1016/j.molcel.2020.07.024] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 07/20/2020] [Accepted: 07/21/2020] [Indexed: 01/05/2023]
Abstract
Mitochondria contain their own gene expression systems, including membrane-bound ribosomes dedicated to synthesizing a few hydrophobic subunits of the oxidative phosphorylation (OXPHOS) complexes. We used a proximity-dependent biotinylation technique, BioID, coupled with mass spectrometry to delineate in baker's yeast a comprehensive network of factors involved in biogenesis of mitochondrial encoded proteins. This mitochondrial gene expression network (MiGENet) encompasses proteins involved in transcription, RNA processing, translation, or protein biogenesis. Our analyses indicate the spatial organization of these processes, thereby revealing basic mechanistic principles and the proteins populating strategically important sites. For example, newly synthesized proteins are directly handed over to ribosomal tunnel exit-bound factors that mediate membrane insertion, co-factor acquisition, or their mounting into OXPHOS complexes in a special early assembly hub. Collectively, the data reveal the connectivity of mitochondrial gene expression, reflecting a unique tailoring of the mitochondrial gene expression system.
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Affiliation(s)
- Abeer Prakash Singh
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden; Department of Medical Biochemistry and Cell Biology, University of Gothenburg, 40530 Gothenburg, Sweden
| | - Roger Salvatori
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden; Department of Medical Biochemistry and Cell Biology, University of Gothenburg, 40530 Gothenburg, Sweden
| | - Wasim Aftab
- BioMedical Center, Faculty of Medicine, Ludwig Maximilians University of Munich, 82152 Planegg-Martinsried, Germany; Graduate School for Quantitative Biosciences (QBM), Ludwig Maximilians University of Munich, 81377 Munich, Germany
| | - Andreas Kohler
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden
| | - Andreas Carlström
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden
| | - Ignasi Forne
- BioMedical Center, Faculty of Medicine, Ludwig Maximilians University of Munich, 82152 Planegg-Martinsried, Germany
| | - Axel Imhof
- BioMedical Center, Faculty of Medicine, Ludwig Maximilians University of Munich, 82152 Planegg-Martinsried, Germany
| | - Martin Ott
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden; Department of Medical Biochemistry and Cell Biology, University of Gothenburg, 40530 Gothenburg, Sweden.
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33
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Alam S, Abdullah CS, Aishwarya R, Morshed M, Bhuiyan MS. Molecular Perspectives of Mitochondrial Adaptations and Their Role in Cardiac Proteostasis. Front Physiol 2020; 11:1054. [PMID: 32982788 PMCID: PMC7481364 DOI: 10.3389/fphys.2020.01054] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Accepted: 07/31/2020] [Indexed: 12/17/2022] Open
Abstract
Mitochondria are the key to properly functioning energy generation in the metabolically demanding cardiomyocytes and thus essential to healthy heart contractility on a beat-to-beat basis. Mitochondria being the central organelle for cellular metabolism and signaling in the heart, its dysfunction leads to cardiovascular disease. The healthy mitochondrial functioning critical to maintaining cardiomyocyte viability and contractility is accomplished by adaptive changes in the dynamics, biogenesis, and degradation of the mitochondria to ensure cellular proteostasis. Recent compelling evidence suggests that the classical protein quality control system in cardiomyocytes is also under constant mitochondrial control, either directly or indirectly. Impairment of cytosolic protein quality control may affect the position of the mitochondria in relation to other organelles, as well as mitochondrial morphology and function, and could also activate mitochondrial proteostasis. Despite a growing interest in the mitochondrial quality control system, very little information is available about the molecular function of mitochondria in cardiac proteostasis. In this review, we bring together current understanding of the adaptations and role of the mitochondria in cardiac proteostasis and describe the adaptive/maladaptive changes observed in the mitochondrial network required to maintain proteomic integrity. We also highlight the key mitochondrial signaling pathways activated in response to proteotoxic stress as a cellular mechanism to protect the heart from proteotoxicity. A deeper understanding of the molecular mechanisms of mitochondrial adaptations and their role in cardiac proteostasis will help to develop future therapeutics to protect the heart from cardiovascular diseases.
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Affiliation(s)
- Shafiul Alam
- Department of Pathology and Translational Pathobiology, Louisiana State University Health Sciences Center, Shreveport, LA, United States
| | - Chowdhury S Abdullah
- Department of Pathology and Translational Pathobiology, Louisiana State University Health Sciences Center, Shreveport, LA, United States
| | - Richa Aishwarya
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA, United States
| | - Mahboob Morshed
- Department of Pathology and Translational Pathobiology, Louisiana State University Health Sciences Center, Shreveport, LA, United States
| | - Md Shenuarin Bhuiyan
- Department of Pathology and Translational Pathobiology, Louisiana State University Health Sciences Center, Shreveport, LA, United States.,Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA, United States
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34
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Genetic Dissection of Hypertrophic Cardiomyopathy with Myocardial RNA-Seq. Int J Mol Sci 2020; 21:ijms21093040. [PMID: 32344918 PMCID: PMC7246737 DOI: 10.3390/ijms21093040] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/20/2020] [Accepted: 04/24/2020] [Indexed: 01/13/2023] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is an inherited disorder of the myocardium, and pathogenic mutations in the sarcomere genes myosin heavy chain 7 (MYH7) and myosin-binding protein C (MYBPC3) explain 60%–70% of observed clinical cases. The heterogeneity of phenotypes observed in HCM patients, however, suggests that novel causative genes or genetic modifiers likely exist. Here, we systemically evaluated RNA-seq data from 28 HCM patients and 9 healthy controls with pathogenic variant identification, differential expression analysis, and gene co-expression and protein–protein interaction network analyses. We identified 43 potential pathogenic variants in 19 genes in 24 HCM patients. Genes with more than one variant included the following: MYBPC3, TTN, MYH7, PSEN2, and LDB3. A total of 2538 protein-coding genes, six microRNAs (miRNAs), and 1617 long noncoding RNAs (lncRNAs) were identified differentially expressed between the groups, including several well-characterized cardiomyopathy-related genes (ANKRD1, FHL2, TGFB3, miR-30d, and miR-154). Gene enrichment analysis revealed that those genes are significantly involved in heart development and physiology. Furthermore, we highlighted four subnetworks: mtDNA-subnetwork, DSP-subnetwork, MYH7-subnetwork, and MYBPC3-subnetwork, which could play significant roles in the progression of HCM. Our findings further illustrate that HCM is a complex disease, which results from mutations in multiple protein-coding genes, modulation by non-coding RNAs and perturbations in gene networks.
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35
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Halperin D, Drabkin M, Wormser O, Yogev Y, Dolgin V, Shorer Z, Gradstein L, Shelef I, Flusser H, Birk OS. Phenotypic variability and mutation hotspot in COX15-related Leigh syndrome. Am J Med Genet A 2020; 182:1506-1512. [PMID: 32232962 DOI: 10.1002/ajmg.a.61577] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 03/12/2020] [Accepted: 03/13/2020] [Indexed: 11/05/2022]
Abstract
COX15 mutations were shown to underlie Leigh syndrome (LS), a progressive subacute necrotizing encephalopathy caused by defects in the mitochondrial respiratory chain. Here, two siblings of consanguineous kindred presented in infancy with a syndrome of hypotonia, nystagmus, psychomotor retardation, and pyramidal signs. Toward the end of their second year, both patients developed progressive quadriparesis, convulsions, and pseudobulbar palsy. Similar to two previously reported cases, one of the two affected siblings had severe hypertrophic obstructive cardiomyopathy, hearing loss, and no visual response. Through linkage analysis and whole-exome sequencing, we identified a homozygous p.R217W mutation in Cytochrome C oxidase assembly protein COX15 homolog. Consistent with the known heterogeneity of mitochondrial diseases in general and that of LS in particular, several phenotypic features were markedly distinguished between the affected siblings and in relation to previous reports of COX15 mutations. Interestingly, of the previously reported five cases of COX15-mutated patients, all of different ethnic origins, three had a p.R217W mutation. We highlight p.R217W as a hotspot mutation in COX15 and delineate the phenotypic variability, both between the patients we describe and in all cases reported to date.
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Affiliation(s)
- Daniel Halperin
- Faculty of Health Sciences, The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Max Drabkin
- Faculty of Health Sciences, The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Ohad Wormser
- Faculty of Health Sciences, The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Yuval Yogev
- Faculty of Health Sciences, The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Vadim Dolgin
- Faculty of Health Sciences, The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Zamir Shorer
- Pediatric Neurology Unit, Division of Pediatrics, Soroka University Medical Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Libe Gradstein
- Department of Ophthalmology, Soroka University Medical Center and Clalit Health Services, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Ilan Shelef
- Faculty of Health Sciences, Department of Imaging, Soroka University Medical Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Hagit Flusser
- Zusman Child Development Center, Division of Pediatrics, Soroka University Medical Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Ohad S Birk
- Faculty of Health Sciences, The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel.,Genetics Institute, Soroka University Medical Center, Beer-Sheva, Israel
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36
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Swenson SA, Moore CM, Marcero JR, Medlock AE, Reddi AR, Khalimonchuk O. From Synthesis to Utilization: The Ins and Outs of Mitochondrial Heme. Cells 2020; 9:E579. [PMID: 32121449 PMCID: PMC7140478 DOI: 10.3390/cells9030579] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 02/19/2020] [Accepted: 02/23/2020] [Indexed: 12/14/2022] Open
Abstract
Heme is a ubiquitous and essential iron containing metallo-organic cofactor required for virtually all aerobic life. Heme synthesis is initiated and completed in mitochondria, followed by certain covalent modifications and/or its delivery to apo-hemoproteins residing throughout the cell. While the biochemical aspects of heme biosynthetic reactions are well understood, the trafficking of newly synthesized heme-a highly reactive and inherently toxic compound-and its subsequent delivery to target proteins remain far from clear. In this review, we summarize current knowledge about heme biosynthesis and trafficking within and outside of the mitochondria.
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Affiliation(s)
| | - Courtney M. Moore
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA;
| | - Jason R. Marcero
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA;
| | - Amy E. Medlock
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA;
- Augusta University/University of Georgia Medical Partnership, Athens, GA 30602, USA
| | - Amit R. Reddi
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA;
- Parker Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Oleh Khalimonchuk
- Department of Biochemistry, University of Nebraska, Lincoln, NE 68588, USA;
- Nebraska Redox Biology Center, University of Nebraska, Lincoln, NE 68588, USA
- Fred and Pamela Buffett Cancer Center, Omaha, NE 68105, USA
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Boral D, Rao VK, Ramasamy S. Archeal Di-O-geranylgeranyl Glyceryl Phosphate Synthase of a UbiA Superfamily Member Provides Insight into the Multiple Human Diseases. Protein Pept Lett 2019; 27:568-573. [PMID: 31814543 DOI: 10.2174/0929866526666191209143948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 10/11/2019] [Accepted: 10/29/2019] [Indexed: 11/22/2022]
Abstract
One of the unique characteristic features of the domain archaea, are the lipids that form the hydrophobic core of their cell membrane. These membrane lipids are characterized by distinctive isoprenoid biochemistry and the building blocks are two core lipid structures, sn-2,3- diphytanyl glycerol diether (archaeol) and sn-2,3-dibiphytanyl diglycerol tetraether (caldarchaeol). Archaeol has two phytanyl chains (C20) in a bilayer structure connected to the glycerol moiety by an ether bond. The enzyme involved in this bilayer formation is Di-O-Geranylgeranyl Glyceryl Phosphate Synthase (DGGGPS), which is a member of a very versatile superfamily of enzymes known as UbiA superfamily. Multiple sequence analysis of the typical members of the UbiA superfamily indicates that the majority of conserved residues are located around the central cavity of these enzymes. Interestingly few of these conserved residues in the human homologs are centrally implicated in several human diseases, on basis of the major mutations reported against these diseases in the earlier clinical studies. It remains to be investigated about the role of these conserved residues in the biochemistry of these enzymes. The binding and active site of these enzymes found to be similar architecture but have different substrate affinities ranging from aromatic to linear compounds. So further investigation of UbiA superfamily may be translated to novel therapeutic and diagnostic application of these proteins in human disease management.
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Affiliation(s)
- Debjyoti Boral
- Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune-411008, India
| | | | - Sureshkumar Ramasamy
- Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune-411008, India
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Hargrave KE, Woods S, Millington O, Chalmers S, Westrop GD, Roberts CW. Multi-Omics Studies Demonstrate Toxoplasma gondii-Induced Metabolic Reprogramming of Murine Dendritic Cells. Front Cell Infect Microbiol 2019; 9:309. [PMID: 31572687 PMCID: PMC6749083 DOI: 10.3389/fcimb.2019.00309] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 08/12/2019] [Indexed: 01/14/2023] Open
Abstract
Toxoplasma gondii is capable of actively invading almost any mammalian cell type including phagocytes. Early events in phagocytic cells such as dendritic cells are not only key to establishing parasite infection, but conversely play a pivotal role in initiating host immunity. It is now recognized that in addition to changes in canonical immune markers and mediators, alteration in metabolism occurs upon activation of phagocytic cells. These metabolic changes are important for supporting the developing immune response, but can affect the availability of nutrients for intracellular pathogens including T. gondii. However, the interaction of T. gondii with these cells and particularly how infection changes their metabolism has not been extensively investigated. Herein, we use a multi-omics approach comprising transcriptomics and metabolomics validated with functional assays to better understand early events in these cells following infection. Analysis of the transcriptome of T. gondii infected bone marrow derived dendritic cells (BMDCs) revealed significant alterations in transcripts associated with cellular metabolism, activation of T cells, inflammation mediated chemokine and cytokine signaling pathways. Multivariant analysis of metabolomic data sets acquired through non-targeted liquid chromatography mass spectroscopy (LCMS) identified metabolites associated with glycolysis, the TCA cycle, oxidative phosphorylation and arginine metabolism as major discriminants between control uninfected and T. gondii infected cells. Consistent with these observations, glucose uptake and lactate dehydrogenase activity were upregulated in T. gondii infected BMDC cultures compared with control BMDCs. Conversely, BMDC mitochondrial membrane potential was reduced in T. gondii-infected cells relative to mitochondria of control BMDCs. These changes to energy metabolism, similar to what has been described following LPS stimulation of BMDCs and macrophages are often termed the Warburg effect. This metabolic reprogramming of cells has been suggested to be an important adaption that provides energy and precursors to facilitate phagocytosis, antigen processing and cytokine production. Other changes to BMDC metabolism are evident following T. gondii infection and include upregulation of arginine degradation concomitant with increased arginase-1 activity and ornithine and proline production. As T. gondii is an arginine auxotroph the resultant reduced cellular arginine levels are likely to curtail parasite multiplication. These results highlight the complex interplay of BMDCs and parasite metabolism within the developing immune response and the consequences for adaptive immunity and pathogen clearance.
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Affiliation(s)
- Kerrie E Hargrave
- Strathclyde Institute of Pharmacy & Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Stuart Woods
- Strathclyde Institute of Pharmacy & Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Owain Millington
- Strathclyde Institute of Pharmacy & Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Susan Chalmers
- Strathclyde Institute of Pharmacy & Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Gareth D Westrop
- Strathclyde Institute of Pharmacy & Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Craig W Roberts
- Strathclyde Institute of Pharmacy & Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
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Brodehl A, Ebbinghaus H, Deutsch MA, Gummert J, Gärtner A, Ratnavadivel S, Milting H. Human Induced Pluripotent Stem-Cell-Derived Cardiomyocytes as Models for Genetic Cardiomyopathies. Int J Mol Sci 2019; 20:ijms20184381. [PMID: 31489928 PMCID: PMC6770343 DOI: 10.3390/ijms20184381] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 08/29/2019] [Accepted: 09/03/2019] [Indexed: 12/17/2022] Open
Abstract
In the last few decades, many pathogenic or likely pathogenic genetic mutations in over hundred different genes have been described for non-ischemic, genetic cardiomyopathies. However, the functional knowledge about most of these mutations is still limited because the generation of adequate animal models is time-consuming and challenging. Therefore, human induced pluripotent stem cells (iPSCs) carrying specific cardiomyopathy-associated mutations are a promising alternative. Since the original discovery that pluripotency can be artificially induced by the expression of different transcription factors, various patient-specific-induced pluripotent stem cell lines have been generated to model non-ischemic, genetic cardiomyopathies in vitro. In this review, we describe the genetic landscape of non-ischemic, genetic cardiomyopathies and give an overview about different human iPSC lines, which have been developed for the disease modeling of inherited cardiomyopathies. We summarize different methods and protocols for the general differentiation of human iPSCs into cardiomyocytes. In addition, we describe methods and technologies to investigate functionally human iPSC-derived cardiomyocytes. Furthermore, we summarize novel genome editing approaches for the genetic manipulation of human iPSCs. This review provides an overview about the genetic landscape of inherited cardiomyopathies with a focus on iPSC technology, which might be of interest for clinicians and basic scientists interested in genetic cardiomyopathies.
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Affiliation(s)
- Andreas Brodehl
- Erich and Hanna Klessmann Institute, Heart and Diabetes Center NRW, University Hospital of the Ruhr-University Bochum, Georgstrasse 11, D-32545 Bad Oeynhausen, Germany.
| | - Hans Ebbinghaus
- Erich and Hanna Klessmann Institute, Heart and Diabetes Center NRW, University Hospital of the Ruhr-University Bochum, Georgstrasse 11, D-32545 Bad Oeynhausen, Germany.
| | - Marcus-André Deutsch
- Department of Thoracic and Cardiovascular Surgery, Heart and Diabetes Center NRW, University Hospital Ruhr-University Bochum, Georgstrasse 11, D-32545 Bad Oeynhausen, Germany.
| | - Jan Gummert
- Erich and Hanna Klessmann Institute, Heart and Diabetes Center NRW, University Hospital of the Ruhr-University Bochum, Georgstrasse 11, D-32545 Bad Oeynhausen, Germany.
- Department of Thoracic and Cardiovascular Surgery, Heart and Diabetes Center NRW, University Hospital Ruhr-University Bochum, Georgstrasse 11, D-32545 Bad Oeynhausen, Germany.
| | - Anna Gärtner
- Erich and Hanna Klessmann Institute, Heart and Diabetes Center NRW, University Hospital of the Ruhr-University Bochum, Georgstrasse 11, D-32545 Bad Oeynhausen, Germany.
| | - Sandra Ratnavadivel
- Erich and Hanna Klessmann Institute, Heart and Diabetes Center NRW, University Hospital of the Ruhr-University Bochum, Georgstrasse 11, D-32545 Bad Oeynhausen, Germany.
| | - Hendrik Milting
- Erich and Hanna Klessmann Institute, Heart and Diabetes Center NRW, University Hospital of the Ruhr-University Bochum, Georgstrasse 11, D-32545 Bad Oeynhausen, Germany.
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McGlaughon JL, Goldstein JL, Thaxton C, Hemphill SE, Berg JS. The progression of the ClinGen gene clinical validity classification over time. Hum Mutat 2019; 39:1494-1504. [PMID: 30311372 PMCID: PMC6190678 DOI: 10.1002/humu.23604] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 07/06/2018] [Accepted: 08/02/2018] [Indexed: 01/18/2023]
Abstract
In order for ClinGen to maintain up-to-date gene-disease clinical validity classifications for use by clinicians and clinical laboratories, an appropriate timeline for reevaluating curated gene-disease associations will need to be determined. To provide guidance on how often a gene-disease association should be recurated, a retrospective analysis of 30 gene curations was performed. Curations were simulated at one-year intervals starting with the year of the first publication to assert disease-causing variants in the gene to observe trends in the classification over time, as well as factors that influenced changes in classification. On average, gene-disease associations spent the least amount of time in the "Moderate" classification before progressing to "Strong" or "Definitive." In contrast, gene-disease associations that spent five or more years in the "Limited" classification were most likely to remain "Limited" or become "Disputed/Refuted." Large population datasets contributed to the reclassification of several gene-disease associations from "Limited" to "Disputed/Refuted." Finally, recent advancements in sequencing technology correlated with an increase in the quantity of case-level evidence that was curated per paper. This study provided a number of key points to consider when determining how often to recurate a gene-disease association.
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Affiliation(s)
- Jennifer L McGlaughon
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Jennifer L Goldstein
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Courtney Thaxton
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Sarah E Hemphill
- Laboratory for Molecular Medicine, Partners Healthcare Personalized Medicine, Cambridge, Massachusetts
| | - Jonathan S Berg
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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41
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Biochemistry of Copper Site Assembly in Heme-Copper Oxidases: A Theme with Variations. Int J Mol Sci 2019; 20:ijms20153830. [PMID: 31387303 PMCID: PMC6696091 DOI: 10.3390/ijms20153830] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Revised: 07/15/2019] [Accepted: 07/16/2019] [Indexed: 01/18/2023] Open
Abstract
Copper is an essential cofactor for aerobic respiration, since it is required as a redox cofactor in Cytochrome c Oxidase (COX). This ancient and highly conserved enzymatic complex from the family of heme-copper oxidase possesses two copper sites: CuA and CuB. Biosynthesis of the oxidase is a complex, stepwise process that requires a high number of assembly factors. In this review, we summarize the state-of-the-art in the assembly of COX, with special emphasis in the assembly of copper sites. Assembly of the CuA site is better understood, being at the same time highly variable among organisms. We also discuss the current challenges that prevent the full comprehension of the mechanisms of assembly and the pending issues in the field.
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42
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Chen Z, Zhang F, Xu H. Human mitochondrial DNA diseases and Drosophila models. J Genet Genomics 2019; 46:201-212. [DOI: 10.1016/j.jgg.2019.03.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 03/05/2019] [Accepted: 03/25/2019] [Indexed: 01/06/2023]
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43
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Cai Z, Guldbrandtsen B, Lund MS, Sahana G. Dissecting closely linked association signals in combination with the mammalian phenotype database can identify candidate genes in dairy cattle. BMC Genet 2019; 20:15. [PMID: 30696404 PMCID: PMC6350337 DOI: 10.1186/s12863-019-0717-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 01/18/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Genome-wide association studies (GWAS) have been successfully implemented in cattle research and breeding. However, moving from the associations to identify the causal variants and reveal underlying mechanisms have proven complicated. In dairy cattle populations, we face a challenge due to long-range linkage disequilibrium (LD) arising from close familial relationships in the studied individuals. Long range LD makes it difficult to distinguish if one or multiple quantitative trait loci (QTL) are segregating in a genomic region showing association with a phenotype. We had two objectives in this study: 1) to distinguish between multiple QTL segregating in a genomic region, and 2) use of external information to prioritize candidate genes for a QTL along with the candidate variants. RESULTS We observed fixing the lead SNP as a covariate can help to distinguish additional close association signal(s). Thereafter, using the mammalian phenotype database, we successfully found candidate genes, in concordance with previous studies, demonstrating the power of this strategy. Secondly, we used variant annotation information to search for causative variants in our candidate genes. The variant information successfully identified known causal mutations and showed the potential to pinpoint the causative mutation(s) which are located in coding regions. CONCLUSIONS Our approach can distinguish multiple QTL segregating on the same chromosome in a single analysis without manual input. Moreover, utilizing information from the mammalian phenotype database and variant effect predictor as post-GWAS analysis could benefit in candidate genes and causative mutations finding in cattle. Our study not only identified additional candidate genes for milk traits, but also can serve as a routine method for GWAS in dairy cattle.
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Affiliation(s)
- Zexi Cai
- Center for Quantitative Genetics and Genomics, Department of Molecular Biology and Genetics, Aarhus University, 8830, Tjele, Denmark.
| | - Bernt Guldbrandtsen
- Center for Quantitative Genetics and Genomics, Department of Molecular Biology and Genetics, Aarhus University, 8830, Tjele, Denmark
| | - Mogens Sandø Lund
- Center for Quantitative Genetics and Genomics, Department of Molecular Biology and Genetics, Aarhus University, 8830, Tjele, Denmark
| | - Goutam Sahana
- Center for Quantitative Genetics and Genomics, Department of Molecular Biology and Genetics, Aarhus University, 8830, Tjele, Denmark
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44
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Palombo V, Milanesi M, Sgorlon S, Capomaccio S, Mele M, Nicolazzi E, Ajmone-Marsan P, Pilla F, Stefanon B, D'Andrea M. Genome-wide association study of milk fatty acid composition in Italian Simmental and Italian Holstein cows using single nucleotide polymorphism arrays. J Dairy Sci 2018; 101:11004-11019. [DOI: 10.3168/jds.2018-14413] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 08/03/2018] [Indexed: 11/19/2022]
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45
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Marshall NC, Klein T, Thejoe M, von Krosigk N, Kizhakkedathu J, Finlay BB, Overall CM. Global Profiling of Proteolysis from the Mitochondrial Amino Terminome during Early Intrinsic Apoptosis Prior to Caspase-3 Activation. J Proteome Res 2018; 17:4279-4296. [PMID: 30371095 DOI: 10.1021/acs.jproteome.8b00675] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The human genome encodes ∼20 mitochondrial proteases, yet we know little of how they sculpt the mitochondrial proteome, particularly during important mitochondrial events such as the initiation of apoptosis. To characterize global mitochondrial proteolysis we refined our technique, terminal amine isotopic labeling of substrates, for mitochondrial SILAC (MS-TAILS) to identify proteolysis across mitochondria and parent cells in parallel. Our MS-TAILS analyses identified 45% of the mitochondrial proteome and identified protein amino (N)-termini from 26% of mitochondrial proteins, the highest reported coverage of the human mitochondrial N-terminome. MS-TAILS revealed 97 previously unknown proteolytic sites. MS-TAILS also identified mitochondrial targeting sequence (MTS) removal by proteolysis during protein import, confirming 101 MTS sites and identifying 135 new MTS sites, revealing a wobbly requirement for the MTS cleavage motif. To examine the relatively unknown initial cleavage events occurring before the well-studied activation of caspase-3 in intrinsic apoptosis, we quantitatively compared N-terminomes of mitochondria and their parent cells before and after initiation of apoptosis at very early time points. By identifying altered levels of >400 N-termini, MS-TAILS analyses implicated specific mitochondrial pathways including protein import, fission, and iron homeostasis in apoptosis initiation. Notably, both staurosporine and Bax activator molecule-7 triggered in common 7 mitochondrial and 85 cellular cleavage events that are potentially part of an essential core of apoptosis-initiating events. All mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium with the dataset identifier PXD009054.
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Affiliation(s)
- Natalie C Marshall
- Michael Smith Laboratories , University of British Columbia , Vancouver , British Columbia , V6T 1Z4 , Canada
| | | | - Maichael Thejoe
- Michael Smith Laboratories , University of British Columbia , Vancouver , British Columbia , V6T 1Z4 , Canada
| | - Niklas von Krosigk
- Michael Smith Laboratories , University of British Columbia , Vancouver , British Columbia , V6T 1Z4 , Canada
| | - Jayachandran Kizhakkedathu
- Department of Pathology and Laboratory Medicine and Department of Chemistry , University of British Columbia , Vancouver , British Columbia V6T 1Z2 , Canada
| | - B Brett Finlay
- Michael Smith Laboratories , University of British Columbia , Vancouver , British Columbia , V6T 1Z4 , Canada
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46
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Signes A, Fernandez-Vizarra E. Assembly of mammalian oxidative phosphorylation complexes I-V and supercomplexes. Essays Biochem 2018; 62:255-270. [PMID: 30030361 PMCID: PMC6056720 DOI: 10.1042/ebc20170098] [Citation(s) in RCA: 170] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 05/08/2018] [Accepted: 05/11/2018] [Indexed: 01/30/2023]
Abstract
The assembly of the five oxidative phosphorylation system (OXPHOS) complexes in the inner mitochondrial membrane is an intricate process. The human enzymes comprise core proteins, performing the catalytic activities, and a large number of 'supernumerary' subunits that play essential roles in assembly, regulation and stability. The correct addition of prosthetic groups as well as chaperoning and incorporation of the structural components require a large number of factors, many of which have been found mutated in cases of mitochondrial disease. Nowadays, the mechanisms of assembly for each of the individual complexes are almost completely understood and the knowledge about the assembly factors involved is constantly increasing. On the other hand, it is now well established that complexes I, III and IV interact with each other, forming the so-called respiratory supercomplexes or 'respirasomes', although the pathways that lead to their formation are still not completely clear. This review is a summary of our current knowledge concerning the assembly of complexes I-V and of the supercomplexes.
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Affiliation(s)
- Alba Signes
- MRC-Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, U.K
| | - Erika Fernandez-Vizarra
- MRC-Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, U.K.
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47
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Human diseases associated with defects in assembly of OXPHOS complexes. Essays Biochem 2018; 62:271-286. [PMID: 30030362 PMCID: PMC6056716 DOI: 10.1042/ebc20170099] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/13/2018] [Accepted: 05/02/2018] [Indexed: 02/02/2023]
Abstract
The structural biogenesis and functional proficiency of the multiheteromeric complexes forming the mitochondrial oxidative phosphorylation system (OXPHOS) require the concerted action of a number of chaperones and other assembly factors, most of which are specific for each complex. Mutations in a large number of these assembly factors are responsible for mitochondrial disorders, in most cases of infantile onset, typically characterized by biochemical defects of single specific complexes. In fact, pathogenic mutations in complex-specific assembly factors outnumber, in many cases, the repertoire of mutations found in structural subunits of specific complexes. The identification of patients with specific defects in assembly factors has provided an important contribution to the nosological characterization of mitochondrial disorders, and has also been a crucial means to identify a huge number of these proteins in humans, which play an essential role in mitochondrial bioenergetics. The wide use of next generation sequencing (NGS) has led to and will allow the identifcation of additional components of the assembly machinery of individual complexes, mutations of which are responsible for human disorders. The functional studies on patients' specimens, together with the creation and characterization of in vivo models, are fundamental to better understand the mechanisms of each of them. A new chapter in this field will be, in the near future, the discovery of mechanisms and actions underlying the formation of supercomplexes, molecular structures formed by the physical, and possibly functional, interaction of some of the individual respiratory complexes, particularly complex I (CI), III (CIII), and IV (CIV).
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48
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Pacheu-Grau D, Rucktäschel R, Deckers M. Mitochondrial dysfunction and its role in tissue-specific cellular stress. Cell Stress 2018; 2:184-199. [PMID: 31225486 PMCID: PMC6551628 DOI: 10.15698/cst2018.07.147] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Mitochondrial bioenergetics require the coordination of two different and independent genomes. Mutations in either genome will affect mitochondrial functionality and produce different sources of cellular stress. Depending on the kind of defect and stress, different tissues and organs will be affected, leading to diverse pathological conditions. There is no curative therapy for mitochondrial diseases, nevertheless, there are strategies described that fight the various stress forms caused by the malfunctioning organelles. Here, we will revise the main kinds of stress generated by mutations in mitochondrial genes and outline several ways of fighting this stress.
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Affiliation(s)
- David Pacheu-Grau
- Department of Cellular Biochemistry, University Medical Center Göttingen, Germany
| | - Robert Rucktäschel
- Department of Cellular Biochemistry, University Medical Center Göttingen, Germany
| | - Markus Deckers
- Department of Cellular Biochemistry, University Medical Center Göttingen, Germany
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49
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Cai Z, Guldbrandtsen B, Lund MS, Sahana G. Dissecting closely linked association signals in combination with the mammalian phenotype database can identify candidate genes in dairy cattle. BMC Genet 2018; 19:30. [PMID: 29751743 PMCID: PMC5948690 DOI: 10.1186/s12863-018-0620-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 04/30/2018] [Indexed: 01/13/2023] Open
Abstract
Background Genome-wide association studies (GWAS) have been successfully implemented in cattle research and breeding. However, moving from the associations to identifying the causal variants and revealing underlying mechanisms have proven complicated. In dairy cattle populations, we face a challenge due to long-range linkage disequilibrium (LD) arising from close familial relationships in the studied individuals. Long range LD makes it difficult to distinguish if one or multiple quantitative trait loci (QTL) are segregating in a genomic region showing association with a phenotype. We had two objectives in this study: 1) to distinguish between multiple QTL segregating in a genomic region, and 2) use of external information to prioritize candidate genes for a QTL along with the candidate variant. Results We observed fixing the lead SNP as a covariate can help to distinguish additional close association signal(s). Thereafter, using the mammalian phenotype database, we successfully found candidate genes, in concordance with previous studies, demonstrating the power of this strategy. Secondly, we used variant annotation information to search for causative variants in our candidate genes. The variant information successfully identified known causal mutations and showed the potential to pinpoint the causative mutation(s) which are located in coding regions. Conclusions Our approach can distinguish multiple QTL segregating on the same chromosome in a single analysis without manual input. Moreover, utilizing information from the mammalian phenotype database and variant effect predictor as post-GWAS analysis could benefit in candidate genes and causative mutations finding in cattle. Our study not only identified additional candidate genes for milk traits, but also can serve as a routine method for GWAS in dairy cattle. Electronic supplementary material The online version of this article (10.1186/s12863-018-0620-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Zexi Cai
- Center for Quantitative Genetics and Genomics, Department of Molecular Biology and Genetics, Aarhus University, 8830, Tjele, Denmark.
| | - Bernt Guldbrandtsen
- Center for Quantitative Genetics and Genomics, Department of Molecular Biology and Genetics, Aarhus University, 8830, Tjele, Denmark
| | - Mogens Sandø Lund
- Center for Quantitative Genetics and Genomics, Department of Molecular Biology and Genetics, Aarhus University, 8830, Tjele, Denmark
| | - Goutam Sahana
- Center for Quantitative Genetics and Genomics, Department of Molecular Biology and Genetics, Aarhus University, 8830, Tjele, Denmark
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50
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Dubinski AF, Camasta R, Soule TGB, Reed BH, Glerum DM. Consequences of cytochrome c oxidase assembly defects for the yeast stationary phase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:445-458. [PMID: 29567354 DOI: 10.1016/j.bbabio.2018.03.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 03/13/2018] [Accepted: 03/19/2018] [Indexed: 12/24/2022]
Abstract
The assembly of cytochrome c oxidase (COX) is essential for a functional mitochondrial respiratory chain, although the consequences of a loss of assembled COX at yeast stationary phase, an excellent model for terminally differentiated cells in humans, remain largely unexamined. In this study, we show that a wild-type respiratory competent yeast strain at stationary phase is characterized by a decreased oxidative capacity, as seen by a reduction in the amount of assembled COX and by a decrease in protein levels of several COX assembly factors. In contrast, loss of assembled COX results in the decreased abundance of many mitochondrial proteins at stationary phase, which is likely due to decreased membrane potential and changes in mitophagy. In addition to an altered mitochondrial proteome, COX assembly mutants display unexpected changes in markers of cellular oxidative stress at stationary phase. Our results suggest that mitochondria may not be a major source of reactive oxygen species at stationary phase in cells lacking an intact respiratory chain.
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Affiliation(s)
- Alicia F Dubinski
- Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Raffaele Camasta
- Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Tyler G B Soule
- Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Bruce H Reed
- Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - D Moira Glerum
- Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada; Waterloo Institute of Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
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