101
|
Prudent J, McBride HM. The mitochondria–endoplasmic reticulum contact sites: a signalling platform for cell death. Curr Opin Cell Biol 2017; 47:52-63. [DOI: 10.1016/j.ceb.2017.03.007] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 02/22/2017] [Accepted: 03/01/2017] [Indexed: 01/23/2023]
|
102
|
Perks KL, Ferreira N, Richman TR, Ermer JA, Kuznetsova I, Shearwood AMJ, Lee RG, Viola HM, Johnstone VPA, Matthews V, Hool LC, Rackham O, Filipovska A. Adult-onset obesity is triggered by impaired mitochondrial gene expression. SCIENCE ADVANCES 2017; 3:e1700677. [PMID: 28835921 PMCID: PMC5559209 DOI: 10.1126/sciadv.1700677] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 07/21/2017] [Indexed: 05/25/2023]
Abstract
Mitochondrial gene expression is essential for energy production; however, an understanding of how it can influence physiology and metabolism is lacking. Several proteins from the pentatricopeptide repeat (PPR) family are essential for the regulation of mitochondrial gene expression, but the functions of the remaining members of this family are poorly understood. We created knockout mice to investigate the role of the PPR domain 1 (PTCD1) protein and show that loss of PTCD1 is embryonic lethal, whereas haploinsufficient, heterozygous mice develop age-induced obesity. The molecular defects and metabolic consequences of mitochondrial protein haploinsufficiency in vivo have not been investigated previously. We show that PTCD1 haploinsufficiency results in increased RNA metabolism, in response to decreased protein synthesis and impaired RNA processing that affect the biogenesis of the respiratory chain, causing mild uncoupling and changes in mitochondrial morphology. We demonstrate that with age, these effects lead to adult-onset obesity that results in liver steatosis and cardiac hypertrophy in response to tissue-specific differential regulation of the mammalian target of rapamycin pathways. Our findings indicate that changes in mitochondrial gene expression have long-term consequences on energy metabolism, providing evidence that haploinsufficiency of PTCD1 can be a major predisposing factor for the development of metabolic syndrome.
Collapse
Affiliation(s)
- Kara L. Perks
- Harry Perkins Institute of Medical Research, Centre for Medical Research, QEII Medical Centre, University of Western Australia, Nedlands, Western Australia 6009, Australia
| | - Nicola Ferreira
- Harry Perkins Institute of Medical Research, Centre for Medical Research, QEII Medical Centre, University of Western Australia, Nedlands, Western Australia 6009, Australia
| | - Tara R. Richman
- Harry Perkins Institute of Medical Research, Centre for Medical Research, QEII Medical Centre, University of Western Australia, Nedlands, Western Australia 6009, Australia
| | - Judith A. Ermer
- Harry Perkins Institute of Medical Research, Centre for Medical Research, QEII Medical Centre, University of Western Australia, Nedlands, Western Australia 6009, Australia
| | - Irina Kuznetsova
- Harry Perkins Institute of Medical Research, Centre for Medical Research, QEII Medical Centre, University of Western Australia, Nedlands, Western Australia 6009, Australia
| | - Anne-Marie J. Shearwood
- Harry Perkins Institute of Medical Research, Centre for Medical Research, QEII Medical Centre, University of Western Australia, Nedlands, Western Australia 6009, Australia
| | - Richard G. Lee
- Harry Perkins Institute of Medical Research, Centre for Medical Research, QEII Medical Centre, University of Western Australia, Nedlands, Western Australia 6009, Australia
| | - Helena M. Viola
- School of Human Sciences, University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Victoria P. A. Johnstone
- School of Human Sciences, University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Vance Matthews
- School of Biomedical Sciences, University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Livia C. Hool
- School of Human Sciences, University of Western Australia, Crawley, Western Australia 6009, Australia
- Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales 2010, Australia
| | - Oliver Rackham
- Harry Perkins Institute of Medical Research, Centre for Medical Research, QEII Medical Centre, University of Western Australia, Nedlands, Western Australia 6009, Australia
- School of Molecular Sciences, University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Aleksandra Filipovska
- Harry Perkins Institute of Medical Research, Centre for Medical Research, QEII Medical Centre, University of Western Australia, Nedlands, Western Australia 6009, Australia
- School of Molecular Sciences, University of Western Australia, Crawley, Western Australia 6009, Australia
| |
Collapse
|
103
|
Burn-induced muscle metabolic derangements and mitochondrial dysfunction are associated with activation of HIF-1α and mTORC1: Role of protein farnesylation. Sci Rep 2017; 7:6618. [PMID: 28747716 PMCID: PMC5529411 DOI: 10.1038/s41598-017-07011-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 06/21/2017] [Indexed: 12/28/2022] Open
Abstract
Metabolic derangements are a clinically significant complication of major trauma (e.g., burn injury) and include various aspects of metabolism, such as insulin resistance, muscle wasting, mitochondrial dysfunction and hyperlactatemia. Nonetheless, the molecular pathogenesis and the relation between these diverse metabolic alterations are poorly understood. We have previously shown that burn increases farnesyltransferase (FTase) expression and protein farnesylation and that FTase inhibitor (FTI) prevents burn-induced hyperlactatemia, insulin resistance, and increased proteolysis in mouse skeletal muscle. In this study, we found that burn injury activated mTORC1 and hypoxia-inducible factor (HIF)-1α, which paralleled dysfunction, morphological alterations (i.e., enlargement, partial loss of cristae structure) and impairment of respiratory supercomplex assembly of the mitochondria, and ER stress. FTI reversed or ameliorated all of these alterations in burned mice. These findings indicate that these burn-induced changes, which encompass various aspects of metabolism, may be linked to one another and require protein farnesylation. Our results provide evidence of involvement of the mTORC1-HIF-1α pathway in burn-induced metabolic derangements. Our study identifies protein farnesylation as a potential hub of the signaling network affecting multiple aspects of metabolic alterations after burn injury and as a novel potential molecular target to improve the clinical outcome of severely burned patients.
Collapse
|
104
|
Abstract
The human mitochondrial glutamate dehydrogenase isoenzymes (hGDH1 and hGDH2) are abundant matrix-localized proteins encoded by nuclear genes. The proteins are synthesized in the cytoplasm, with an atypically long N-terminal mitochondrial targeting sequence (MTS). The results of secondary structure predictions suggest the presence of two α-helices within the N-terminal region of the MTS. Results from deletion analyses indicate that individual helices have limited ability to direct protein import and matrix localization, but that there is a synergistic interaction when both helices are present [Biochem. J. (2016) 473: , 2813-2829]. Mutagenesis of the MTS cleavage sites blocked post-import removal of the presequences, but did not impede import. The authors propose that the high matrix levels of hGDH can be attributed to the unusual length and secondary structure of the MTS.
Collapse
|
105
|
Regulated membrane remodeling by Mic60 controls formation of mitochondrial crista junctions. Nat Commun 2017; 8:15258. [PMID: 28561061 PMCID: PMC5460017 DOI: 10.1038/ncomms15258] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 03/14/2017] [Indexed: 01/20/2023] Open
Abstract
The mitochondrial contact site and cristae organizing system (MICOS) is crucial for the formation of crista junctions and mitochondrial inner membrane architecture. MICOS contains two core components. Mic10 shows membrane-bending activity, whereas Mic60 (mitofilin) forms contact sites between inner and outer membranes. Here we report that Mic60 deforms liposomes into thin membrane tubules and thus displays membrane-shaping activity. We identify a membrane-binding site in the soluble intermembrane space-exposed part of Mic60. This membrane-binding site is formed by a predicted amphipathic helix between the conserved coiled-coil and mitofilin domains. The mitofilin domain negatively regulates the membrane-shaping activity of Mic60. Binding of Mic19 to the mitofilin domain modulates this activity. Membrane binding and shaping by the conserved Mic60–Mic19 complex is crucial for crista junction formation, mitochondrial membrane architecture and efficient respiratory activity. Mic60 thus plays a dual role by shaping inner membrane crista junctions and forming contact sites with the outer membrane. The MICOS complex has an essential role in crista junction formation and mitochondrial inner membrane morphology. Here, the authors show that one of its components, Mic60, known to form contact sites between inner and outer membranes, also displays membrane-shaping activity.
Collapse
|
106
|
Mitochondrial contact site and cristae organizing system: A central player in membrane shaping and crosstalk. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:1481-1489. [PMID: 28526561 DOI: 10.1016/j.bbamcr.2017.05.004] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 05/01/2017] [Indexed: 01/08/2023]
Abstract
Mitochondria are multifunctional metabolic factories and integrative signaling organelles of eukaryotic cells. The structural basis for their numerous functions is a complex and dynamic double-membrane architecture. The outer membrane connects mitochondria to the cytosol and other organelles. The inner membrane is composed of a boundary region and highly folded cristae membranes. The evolutionarily conserved mitochondrial contact site and cristae organizing system (MICOS) connects the two inner membrane domains via formation and stabilization of crista junction structures. Moreover, MICOS establishes contact sites between inner and outer mitochondrial membranes by interacting with outer membrane protein complexes. MICOS deficiency leads to a grossly altered inner membrane architecture resulting in far-reaching functional perturbations in mitochondria. Consequently, mutations affecting the function of MICOS are responsible for a diverse spectrum of human diseases. In this article, we summarize recent insights and concepts on the role of MICOS in the organization of mitochondrial membranes. This article is part of a Special Issue entitled: Membrane Contact Sites edited by Christian Ungermann and Benoit Kornmann.
Collapse
|
107
|
Di Benedetto G, Gerbino A, Lefkimmiatis K. Shaping mitochondrial dynamics: The role of cAMP signalling. Biochem Biophys Res Commun 2017; 500:65-74. [PMID: 28501614 DOI: 10.1016/j.bbrc.2017.05.041] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 05/07/2017] [Indexed: 12/25/2022]
Abstract
In recent years, our idea of mitochondria evolved from "mere" energy and metabolite producers to key regulators of many cellular functions. In order to preserve and protect their functional status, these organelles engage a number of dynamic processes that allow them to decrease accumulated burden and maintain their homeostasis. Indeed, mitochondria can unite (fusion), divide (fission), position themselves strategically in the cell (motility/trafficking) and if irreversibly damaged or dysfunctional eliminated (mitophagy). These dynamic processes can be controlled both by mitochondrial and cellular signalling pathways, hence allowing mitochondria to tune their function to the cellular needs. Among the regulatory mechanisms, reversible phosphorylation downstream the cyclic AMP (cAMP) signalling cascade was shown to deeply influence mitochondrial dynamics. This review explores the emerging evidence suggesting that cAMP is a key player in the orchestration of mitochondrial fusion/fission, motility and mitophagy, extending the repertoire of this second messenger, which is now recognised as a major regulator of mitochondrial homeostasis.
Collapse
Affiliation(s)
- Giulietta Di Benedetto
- Neuroscience Institute, Italian National Research Council (CNR), Venetian Institute of Molecular Medicine, 35131, Padova, Italy
| | - Andrea Gerbino
- Department of Biosciences, Biotechnology and Biopharmaceutics, University of Bari, Bari, Italy
| | - Konstantinos Lefkimmiatis
- Neuroscience Institute, Italian National Research Council (CNR), Venetian Institute of Molecular Medicine, 35131, Padova, Italy.
| |
Collapse
|
108
|
Aguilera-Gomez A, Rabouille C. Membrane-bound organelles versus membrane-less compartments and their control of anabolic pathways in Drosophila. Dev Biol 2017; 428:310-317. [PMID: 28377034 DOI: 10.1016/j.ydbio.2017.03.029] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 03/27/2017] [Accepted: 03/27/2017] [Indexed: 12/29/2022]
Abstract
Classically, we think of cell compartmentalization as being achieved by membrane-bound organelles. It has nevertheless emerged that membrane-less assemblies also largely contribute to this compartmentalization. Here, we compare the characteristics of both types of compartmentalization in term of maintenance of functional identities. Furthermore, membrane less-compartments are critical for sustaining developmental and cell biological events as they control major metabolic pathways. We describe two examples related to this issue in Drosophila, the role of P-bodies in the translational control of gurken in the Drosophila oocyte, and the formation of Sec bodies upon amino-acid starvation in Drosophila cells.
Collapse
Affiliation(s)
| | - Catherine Rabouille
- Hubrecht Institute of the KNAW & UMC Utrecht, 3584 CT Utrecht, The Netherlands; Department of Cell Biology, UMC Utrecht, The Netherlands; Department of Cell Biology, UMC Groningen, The Netherlands.
| |
Collapse
|
109
|
Rampelt H, Zerbes RM, van der Laan M, Pfanner N. Role of the mitochondrial contact site and cristae organizing system in membrane architecture and dynamics. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:737-746. [DOI: 10.1016/j.bbamcr.2016.05.020] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 05/12/2016] [Accepted: 05/17/2016] [Indexed: 12/22/2022]
|
110
|
Cardiolipin and mitochondrial cristae organization. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:1156-1163. [PMID: 28336315 DOI: 10.1016/j.bbamem.2017.03.013] [Citation(s) in RCA: 197] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 03/03/2017] [Accepted: 03/18/2017] [Indexed: 11/23/2022]
Abstract
A fundamental question in cell biology, under investigation for over six decades, is the structural organization of mitochondrial cristae. Long known to harbor electron transport chain proteins, crista membrane integrity is key to establishment of the proton gradient that drives oxidative phosphorylation. Visualization of cristae morphology by electron microscopy/tomography has provided evidence that cristae are tube-like extensions of the mitochondrial inner membrane (IM) that project into the matrix space. Reconciling ultrastructural data with the lipid composition of the IM provides support for a continuously curved cylindrical bilayer capped by a dome-shaped tip. Strain imposed by the degree of curvature is relieved by an asymmetric distribution of phospholipids in monolayer leaflets that comprise cristae membranes. The signature mitochondrial lipid, cardiolipin (~18% of IM phospholipid mass), and phosphatidylethanolamine (34%) segregate to the negatively curved monolayer leaflet facing the crista lumen while the opposing, positively curved, matrix-facing monolayer leaflet contains predominantly phosphatidylcholine. Associated with cristae are numerous proteins that function in distinctive ways to establish and/or maintain their lipid repertoire and structural integrity. By combining unique lipid components with a set of protein modulators, crista membranes adopt and maintain their characteristic morphological and functional properties. Once established, cristae ultrastructure has a direct impact on oxidative phosphorylation, apoptosis, fusion/fission as well as diseases of compromised energy metabolism.
Collapse
|
111
|
Prasai K. Regulation of mitochondrial structure and function by protein import: A current review. ACTA ACUST UNITED AC 2017; 24:107-122. [PMID: 28400074 DOI: 10.1016/j.pathophys.2017.03.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Revised: 03/09/2017] [Accepted: 03/10/2017] [Indexed: 12/14/2022]
Abstract
By generating the majority of a cell's ATP, mitochondria permit a vast range of reactions necessary for life. Mitochondria also perform other vital functions including biogenesis and assembly of iron-sulfur proteins, maintenance of calcium homeostasis, and activation of apoptosis. Accordingly, mitochondrial dysfunction has been linked with the pathology of many clinical conditions including cancer, type 2 diabetes, cardiomyopathy, and atherosclerosis. The ongoing maintenance of mitochondrial structure and function requires the import of nuclear-encoded proteins and for this reason, mitochondrial protein import is indispensible for cell viability. As mitochondria play central roles in determining if cells live or die, a comprehensive understanding of mitochondrial structure, protein import, and function is necessary for identifying novel drugs that may destroy harmful cells while rescuing or protecting normal ones to preserve tissue integrity. This review summarizes our current knowledge on mitochondrial architecture, mitochondrial protein import, and mitochondrial function. Our current comprehension of how mitochondrial functions maintain cell homeostasis and how cell death occurs as a result of mitochondrial stress are also discussed.
Collapse
Affiliation(s)
- Kanchanjunga Prasai
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA.
| |
Collapse
|
112
|
Dudek J, Maack C. Barth syndrome cardiomyopathy. Cardiovasc Res 2017; 113:399-410. [PMID: 28158532 DOI: 10.1093/cvr/cvx014] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 12/19/2016] [Accepted: 01/04/2017] [Indexed: 02/02/2023] Open
Abstract
Barth syndrome (BTHS) is an inherited form of cardiomyopathy, caused by a mutation within the gene encoding the mitochondrial transacylase tafazzin. Tafazzin is involved in the biosynthesis of the unique phospholipid cardiolipin (CL), which is almost exclusively found in mitochondrial membranes. CL directly interacts with a number of essential protein complexes in the mitochondrial membranes including the respiratory chain, mitochondrial metabolite carriers, and proteins, involved in shaping mitochondrial morphology. Here we describe, how in BTHS CL deficiency causes changes in the morphology of mitochondria, structural changes in the respiratory chain, decreased respiration, and increased generation of reactive oxygen species. A large number of cellular and animal models for BTHS have been established to elucidate how mitochondrial dysfunction induces sarcomere disorganization and reduced contractility, resulting in dilated cardiomyopathy in vivo.
Collapse
Affiliation(s)
- Jan Dudek
- Department of Cellular Biochemistry, University Medical Center Göttingen, 37073 Göttingen, Germany
| | - Christoph Maack
- Klinik für Innere Medizin III, Universitätsklinikum des Saarlandes, 66421 Homburg/Saar, Germany
| |
Collapse
|
113
|
Michaud M, Prinz WA, Jouhet J. Glycerolipid synthesis and lipid trafficking in plant mitochondria. FEBS J 2017; 284:376-390. [PMID: 27406373 PMCID: PMC6224293 DOI: 10.1111/febs.13812] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 06/22/2016] [Accepted: 07/11/2016] [Indexed: 11/27/2022]
Abstract
Lipid trafficking between mitochondria and other organelles is required for mitochondrial membrane biogenesis and signaling. This lipid exchange occurs by poorly understood nonvesicular mechanisms. In yeast and mammalian cells, this lipid exchange is thought to take place at contact sites between mitochondria and the ER or vacuolar membranes. Some proteins involved in the tethering between membranes or in the transfer of lipids in mitochondria have been identified. However, in plants, little is known about the synthesis of mitochondrial membranes. Mitochondrial membrane biogenesis is particularly important and noteworthy in plants as the lipid composition of mitochondrial membranes is dramatically changed during phosphate starvation and other stresses. This review focuses on the principal pathways involved in the synthesis of the most abundant mitochondrial glycerolipids in plants and the lipid trafficking that is required for plant mitochondria membrane biogenesis.
Collapse
Affiliation(s)
- Morgane Michaud
- Laboratory of Cell and Molecular Biology, National Institutes of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, USA
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168 CNRS-CEA-INRA-Université Grenoble Alpes, Grenoble, France
| | - William A Prinz
- Laboratory of Cell and Molecular Biology, National Institutes of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, USA
| | - Juliette Jouhet
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168 CNRS-CEA-INRA-Université Grenoble Alpes, Grenoble, France
| |
Collapse
|
114
|
Herrera-Cruz MS, Simmen T. Of yeast, mice and men: MAMs come in two flavors. Biol Direct 2017; 12:3. [PMID: 28122638 PMCID: PMC5267431 DOI: 10.1186/s13062-017-0174-5] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 01/18/2017] [Indexed: 12/15/2022] Open
Abstract
The past decade has seen dramatic progress in our understanding of membrane contact sites (MCS). Important examples of these are endoplasmic reticulum (ER)-mitochondria contact sites. ER-mitochondria contacts have originally been discovered in mammalian tissue, where they have been designated as mitochondria-associated membranes (MAMs). It is also in this model system, where the first critical MAM proteins have been identified, including MAM tethering regulators such as phospho-furin acidic cluster sorting protein 2 (PACS-2) and mitofusin-2. However, the past decade has seen the discovery of the MAM also in the powerful yeast model system Saccharomyces cerevisiae. This has led to the discovery of novel MAM tethers such as the yeast ER-mitochondria encounter structure (ERMES), absent in the mammalian system, but whose regulators Gem1 and Lam6 are conserved. While MAMs, sometimes referred to as mitochondria-ER contacts (MERCs), regulate lipid metabolism, Ca2+ signaling, bioenergetics, inflammation, autophagy and apoptosis, not all of these functions exist in both systems or operate differently. This biological difference has led to puzzling discrepancies on findings obtained in yeast or mammalian cells at the moment. Our review aims to shed some light onto mechanistic differences between yeast and mammalian MAM and their underlying causes. Reviewers: This article was reviewed by Paola Pizzo (nominated by Luca Pellegrini), Maya Schuldiner and György Szabadkai (nominated by Luca Pellegrini).
Collapse
Affiliation(s)
- Maria Sol Herrera-Cruz
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, T6G2H7, Canada
| | - Thomas Simmen
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, T6G2H7, Canada.
| |
Collapse
|
115
|
Braun RJ, Zerbes RM, Steinberg F, Gris D, Dumit VI. Threading Granules in Freiburg. 2 nd International Symposium on "One Mitochondrion, Many Diseases - Biological and Molecular Perspectives", a FRIAS Junior Researcher Conference, Freiburg im Breisgau, Germany, March 9 th/10 th, 2016. MICROBIAL CELL 2016; 3:565-568. [PMID: 28357325 PMCID: PMC5349212 DOI: 10.15698/mic2016.11.540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Altered mitochondrial activities play an important role in many different human
disorders, including cancer and neurodegeneration. At the Freiburg Institute of
Advanced Studies (FRIAS) Junior Researcher Conference “One Mitochondrion, Many
Diseases - Biological and Molecular Perspectives” (University of Freiburg,
Freiburg, Germany), junior and experienced researches discussed common and
distinct mechanisms of mitochondrial contributions to various human
disorders.
Collapse
Affiliation(s)
- Ralf J Braun
- Institute of Cell Biology, University of Bayreuth, 95440 Bayreuth, Germany
| | - Ralf M Zerbes
- Institute for Biochemistry and Molecular Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Florian Steinberg
- ZBSA Center for Biological Systems Analysis, AG Steinberg, University of Freiburg, 79104 Freiburg, Germany
| | - Denis Gris
- Program of Immunology, Department of Pediatrics, CR-CHUS, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Verónica I Dumit
- ZBSA Center for Biological Systems Analysis, Core Facility Proteomics, University of Freiburg, 79104 Freiburg, Germany
| |
Collapse
|
116
|
Wai T, Saita S, Nolte H, Müller S, König T, Richter-Dennerlein R, Sprenger HG, Madrenas J, Mühlmeister M, Brandt U, Krüger M, Langer T. The membrane scaffold SLP2 anchors a proteolytic hub in mitochondria containing PARL and the i-AAA protease YME1L. EMBO Rep 2016; 17:1844-1856. [PMID: 27737933 DOI: 10.15252/embr.201642698] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 09/13/2016] [Accepted: 09/15/2016] [Indexed: 02/05/2023] Open
Abstract
The SPFH (stomatin, prohibitin, flotillin, HflC/K) superfamily is composed of scaffold proteins that form ring-like structures and locally specify the protein-lipid composition in a variety of cellular membranes. Stomatin-like protein 2 (SLP2) is a member of this superfamily that localizes to the mitochondrial inner membrane (IM) where it acts as a membrane organizer. Here, we report that SLP2 anchors a large protease complex composed of the rhomboid protease PARL and the i-AAA protease YME1L, which we term the SPY complex (for SLP2-PARL-YME1L). Association with SLP2 in the SPY complex regulates PARL-mediated processing of PTEN-induced kinase PINK1 and the phosphatase PGAM5 in mitochondria. Moreover, SLP2 inhibits the stress-activated peptidase OMA1, which can bind to SLP2 and cleaves PGAM5 in depolarized mitochondria. SLP2 restricts OMA1-mediated processing of the dynamin-like GTPase OPA1 allowing stress-induced mitochondrial hyperfusion under starvation conditions. Together, our results reveal an important role of SLP2 membrane scaffolds for the spatial organization of IM proteases regulating mitochondrial dynamics, quality control, and cell survival.
Collapse
Affiliation(s)
- Timothy Wai
- Institute for Genetics Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and University of Cologne, Cologne, Germany
| | - Shotaro Saita
- Institute for Genetics Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and University of Cologne, Cologne, Germany
| | - Hendrik Nolte
- Institute for Genetics Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and University of Cologne, Cologne, Germany
| | - Sebastian Müller
- Institute for Genetics Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and University of Cologne, Cologne, Germany
| | - Tim König
- Institute for Genetics Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and University of Cologne, Cologne, Germany
| | - Ricarda Richter-Dennerlein
- Institute for Genetics Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and University of Cologne, Cologne, Germany
| | - Hans-Georg Sprenger
- Institute for Genetics Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and University of Cologne, Cologne, Germany
| | - Joaquin Madrenas
- Microbiome and Disease Tolerance Centre, Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada
| | - Mareike Mühlmeister
- Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Ulrich Brandt
- Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Marcus Krüger
- Institute for Genetics Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and University of Cologne, Cologne, Germany
| | - Thomas Langer
- Institute for Genetics Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and University of Cologne, Cologne, Germany .,Center for Molecular Medicine (CMMC), University of Cologne, Cologne, Germany
| |
Collapse
|
117
|
Plecitá-Hlavatá L, Ježek P. Integration of superoxide formation and cristae morphology for mitochondrial redox signaling. Int J Biochem Cell Biol 2016; 80:31-50. [PMID: 27640755 DOI: 10.1016/j.biocel.2016.09.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 09/09/2016] [Accepted: 09/12/2016] [Indexed: 12/16/2022]
Abstract
The mitochondrial network provides the central cell's energetic and regulatory unit, which besides ATP and metabolite production participates in cellular signaling through regulated reactive oxygen species (ROS) production and various protein/ion fluxes. The inner membrane forms extensive folds, called cristae, i.e. cavities enfolded from and situated perpendicularly to its inner boundary membrane portion, which encompasses an inner cylinder within the outer membrane tubule. Mitochondrial cristae ultramorphology reflects various metabolic, physiological or pathological states. Since the mitochondrion is typically a predominant superoxide source and generated ROS also serve for the creation of information redox signals, we review known relationships between ROS generation within the respiratory chain complexes of cristae and cristae morphology. Notably, it is emphasized that cristae shape is governed by ATP-synthase dimers, MICOS complexes, OPA1 isoforms and the umbrella of their regulation, and also dependent on local protonmotive force (electrical potential component) in cristae. Cristae are also affected by redox-sensitive kinases/phosphatases or p66SHC. ATP-synthase dimers decrease in the inflated intracristal space, diminishing pH and hypothetically having minimal superoxide formation. Matrix-released signaling superoxide/H2O2 is predominantly integrated along mitochondrial tubules, whereas the diffusion of intracristal signaling ROS species is controlled by crista junctions, the widening of which enables specific retrograde redox signaling such as during hypoxic cell adaptation. Other physiological cases of H2O2 release from the mitochondrion include the modulation of insulin release in pancreatic β-cells, enhancement of insulin signaling in peripheral tissues, signaling by T-cell receptors, retrograde signaling during the cell cycle and cell differentiation, specifically that of adipocytes.
Collapse
Affiliation(s)
- Lydie Plecitá-Hlavatá
- Department of Membrane Transport Biophysics, No.75, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Petr Ježek
- Department of Membrane Transport Biophysics, No.75, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
| |
Collapse
|
118
|
Guarani V, Jardel C, Chrétien D, Lombès A, Bénit P, Labasse C, Lacène E, Bourillon A, Imbard A, Benoist JF, Dorboz I, Gilleron M, Goetzman ES, Gaignard P, Slama A, Elmaleh-Bergès M, Romero NB, Rustin P, Ogier de Baulny H, Paulo JA, Harper JW, Schiff M. QIL1 mutation causes MICOS disassembly and early onset fatal mitochondrial encephalopathy with liver disease. eLife 2016; 5. [PMID: 27623147 PMCID: PMC5021520 DOI: 10.7554/elife.17163] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 08/24/2016] [Indexed: 12/16/2022] Open
Abstract
Previously, we identified QIL1 as a subunit of mitochondrial contact site (MICOS) complex and demonstrated a role for QIL1 in MICOS assembly, mitochondrial respiration, and cristae formation critical for mitochondrial architecture (Guarani et al., 2015). Here, we identify QIL1 null alleles in two siblings displaying multiple clinical symptoms of early-onset fatal mitochondrial encephalopathy with liver disease, including defects in respiratory chain function in patient muscle. QIL1 absence in patients' fibroblasts was associated with MICOS disassembly, abnormal cristae, mild cytochrome c oxidase defect, and sensitivity to glucose withdrawal. QIL1 expression rescued cristae defects, and promoted re-accumulation of MICOS subunits to facilitate MICOS assembly. MICOS assembly and cristae morphology were not efficiently rescued by over-expression of other MICOS subunits in patient fibroblasts. Taken together, these data provide the first evidence of altered MICOS assembly linked with a human mitochondrial disease and confirm a central role for QIL1 in stable MICOS complex formation.
Collapse
Affiliation(s)
- Virginia Guarani
- Department of Cell Biology, Harvard Medical School, Boston, United States
| | - Claude Jardel
- Inserm U1016, Institut Cochin, CNRS UMR 8104, Paris, France.,Department of Biochemistry, APHP, GHU Pitié-Salpêtrière, Paris, France.,Université Paris-Descartes, Paris, France
| | - Dominique Chrétien
- UMR1141, PROTECT, INSERM, Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
| | - Anne Lombès
- Inserm U1016, Institut Cochin, CNRS UMR 8104, Paris, France.,Department of Biochemistry, APHP, GHU Pitié-Salpêtrière, Paris, France.,Université Paris-Descartes, Paris, France
| | - Paule Bénit
- UMR1141, PROTECT, INSERM, Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
| | - Clémence Labasse
- Neuromuscular morphology unit, Institut de Myologie, GHU Pitié-Salpêtrière, APHP, Paris, France
| | - Emmanuelle Lacène
- Neuromuscular morphology unit, Institut de Myologie, GHU Pitié-Salpêtrière, APHP, Paris, France
| | - Agnès Bourillon
- Department of Biochemistry, Hôpital Robert Debré, APHP, Paris, France
| | - Apolline Imbard
- Department of Biochemistry, Hôpital Robert Debré, APHP, Paris, France
| | | | - Imen Dorboz
- UMR1141, PROTECT, INSERM, Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
| | - Mylène Gilleron
- Inserm U1016, Institut Cochin, CNRS UMR 8104, Paris, France.,Department of Biochemistry, APHP, GHU Pitié-Salpêtrière, Paris, France.,Université Paris-Descartes, Paris, France
| | - Eric S Goetzman
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, United States.,University of Pittsburgh, Pittsburgh, United States.,Children's Hospital of Pittsburgh of UPMC, Pittsburgh, United States
| | - Pauline Gaignard
- Department of Biochemistry, Hôpital Bicêtre, APHP, Paris, France
| | - Abdelhamid Slama
- Department of Biochemistry, Hôpital Bicêtre, APHP, Paris, France
| | | | - Norma B Romero
- Neuromuscular morphology unit, Institut de Myologie, GHU Pitié-Salpêtrière, APHP, Paris, France
| | - Pierre Rustin
- UMR1141, PROTECT, INSERM, Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
| | - Hélène Ogier de Baulny
- Reference Center for Inborn Errors of Metabolism, Robert Debré University Hospital, APHP, Paris, France
| | - Joao A Paulo
- Department of Cell Biology, Harvard Medical School, Boston, United States
| | - J Wade Harper
- Department of Cell Biology, Harvard Medical School, Boston, United States
| | - Manuel Schiff
- UMR1141, PROTECT, INSERM, Université Paris-Diderot, Sorbonne Paris Cité, Paris, France.,Reference Center for Inborn Errors of Metabolism, Robert Debré University Hospital, APHP, Paris, France
| |
Collapse
|
119
|
Intramitochondrial phospholipid trafficking. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:81-89. [PMID: 27542541 DOI: 10.1016/j.bbalip.2016.08.006] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 08/03/2016] [Accepted: 08/11/2016] [Indexed: 12/29/2022]
Abstract
Mitochondrial functions and architecture rely on a defined lipid composition of their outer and inner membranes, which are characterized by a high content of non-bilayer phospholipids such as cardiolipin (CL) and phosphatidylethanolamine (PE). Mitochondrial membrane lipids are synthesized in the endoplasmic reticulum (ER) or within mitochondria from ER-derived precursor lipids, are asymmetrically distributed within mitochondria and can relocate in response to cellular stress. Maintenance of lipid homeostasis thus requires multiple lipid transport processes to be orchestrated within mitochondria. Recent findings identified members of the Ups/PRELI family as specific lipid transfer proteins in mitochondria that shuttle phospholipids between mitochondrial membranes. They cooperate with membrane organizing proteins that preserve the spatial organization of mitochondrial membranes and the formation of membrane contact sites, unravelling an intimate crosstalk of membrane lipid transport and homeostasis with the structural organization of mitochondria. This article is part of a Special Issue entitled: Lipids of Mitochondria edited by Guenther Daum.
Collapse
|
120
|
Anand R, Strecker V, Urbach J, Wittig I, Reichert AS. Mic13 Is Essential for Formation of Crista Junctions in Mammalian Cells. PLoS One 2016; 11:e0160258. [PMID: 27479602 PMCID: PMC4968808 DOI: 10.1371/journal.pone.0160258] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 07/15/2016] [Indexed: 12/11/2022] Open
Abstract
Mitochondrial cristae are connected to the inner boundary membrane via crista junctions which are implicated in the regulation of oxidative phosphorylation, apoptosis, and import of lipids and proteins. The MICOS complex determines formation of crista junctions. We performed complexome profiling and identified Mic13, also termed Qil1, as a subunit of the MICOS complex. We show that MIC13 is an inner membrane protein physically interacting with MIC60, a central subunit of the MICOS complex. Using the CRISPR/Cas method we generated the first cell line deleted for MIC13. These knockout cells show a complete loss of crista junctions demonstrating that MIC13 is strictly required for the formation of crista junctions. MIC13 is required for the assembly of MIC10, MIC26, and MIC27 into the MICOS complex. However, it is not needed for the formation of the MIC60/MIC19/MIC25 subcomplex suggesting that the latter is not sufficient for crista junction formation. MIC13 is also dispensable for assembly of respiratory chain complexes and for maintaining mitochondrial network morphology. Still, lack of MIC13 resulted in a moderate reduction of mitochondrial respiration. In summary, we show that MIC13 has a fundamental role in crista junction formation and that assembly of respiratory chain supercomplexes is independent of mitochondrial cristae shape.
Collapse
Affiliation(s)
- Ruchika Anand
- Institute of Biochemistry and Molecular Biology I, Heinrich Heine University, Medical Faculty, Universitätsstr. 1, 40225, Düsseldorf, Germany
| | - Valentina Strecker
- Functional Proteomics, SFB 815 Core Unit, Faculty of Medicine, Goethe-University, Frankfurt am Main, Germany
| | - Jennifer Urbach
- Institute of Biochemistry and Molecular Biology I, Heinrich Heine University, Medical Faculty, Universitätsstr. 1, 40225, Düsseldorf, Germany
| | - Ilka Wittig
- Functional Proteomics, SFB 815 Core Unit, Faculty of Medicine, Goethe-University, Frankfurt am Main, Germany
- Cluster of Excellence “Macromolecular Complexes”, Goethe University, Frankfurt am Main, Germany
- German Center of Cardiovascular Research (DZHK), Partner site RheinMain, Frankfurt, Germany
| | - Andreas S. Reichert
- Institute of Biochemistry and Molecular Biology I, Heinrich Heine University, Medical Faculty, Universitätsstr. 1, 40225, Düsseldorf, Germany
- * E-mail:
| |
Collapse
|
121
|
Dimmer KS, Rapaport D. Mitochondrial contact sites as platforms for phospholipid exchange. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:69-80. [PMID: 27477677 DOI: 10.1016/j.bbalip.2016.07.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 07/21/2016] [Accepted: 07/22/2016] [Indexed: 12/15/2022]
Abstract
Mitochondria are unique organelles that contain their own - although strongly reduced - genome, and are surrounded by two membranes. While most cellular phospholipid biosynthesis takes place in the ER, mitochondria harbor the whole spectrum of glycerophospholipids common to biological membranes. Mitochondria also contribute to overall phospholipid biosynthesis in cells by producing phosphatidylethanolamine, phosphatidylglycerol, and cardiolipin. Considering these features, it is not surprising that mitochondria maintain highly active exchange of phospholipids with other cellular compartments. In this contribution we describe the transport of phospholipids between mitochondria and other organelles, and discuss recent developments in our understanding of the molecular functions of the protein complexes that mediate these processes. This article is part of a Special Issue entitled: Lipids of Mitochondria edited by Guenther Daum.
Collapse
Affiliation(s)
- Kai Stefan Dimmer
- Interfaculty Institute of Biochemistry, University of Tübingen, Hoppe-Seyler-Str. 4, 72076 Tübingen, Germany.
| | - Doron Rapaport
- Interfaculty Institute of Biochemistry, University of Tübingen, Hoppe-Seyler-Str. 4, 72076 Tübingen, Germany
| |
Collapse
|
122
|
Carrì MT, D'Ambrosi N, Cozzolino M. Pathways to mitochondrial dysfunction in ALS pathogenesis. Biochem Biophys Res Commun 2016; 483:1187-1193. [PMID: 27416757 DOI: 10.1016/j.bbrc.2016.07.055] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 07/10/2016] [Indexed: 12/20/2022]
Abstract
Alterations in the structure and functions of mitochondria are a typical trait of Amyotrophic Lateral Sclerosis, a neurodegenerative disease characterized by a prominent degeneration of upper and lower motor neurons. The known gene mutations that are responsible for a small fraction of ALS cases point to a complex interplay between different mechanisms in the disease pathogenesis. Here we will briefly overview the genetic and mechanistic evidence that make dysfunction of mitochondria a candidate major player in this process.
Collapse
Affiliation(s)
- Maria Teresa Carrì
- Department of Biology, Università di Roma "Tor Vergata", Via della Ricerca Scientifica, 00133, Rome, Italy; Fondazione Santa Lucia, IRCCS, Via del Fosso di Fiorano 64, 00143, Rome, Italy.
| | - Nadia D'Ambrosi
- Institute of Anatomy and Cell Biology, Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, 00168, Rome, Italy.
| | - Mauro Cozzolino
- Institute of Translational Pharmacology, CNR, Via del Fosso del Cavaliere 100, 00133, Rome, Italy.
| |
Collapse
|
123
|
Effects of lipids on mitochondrial functions. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:102-113. [PMID: 27349299 DOI: 10.1016/j.bbalip.2016.06.015] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 06/16/2016] [Accepted: 06/21/2016] [Indexed: 11/23/2022]
Abstract
Mitochondria contain two membranes: the outer and inner membrane. Whereas the outer membrane is particularly enriched in phospholipids, the inner membrane has an unusual high protein content and forms large invaginations termed cristae. The proper phospholipid composition of the membranes is crucial for mitochondrial functions. Phospholipids affect activity, biogenesis and stability of protein complexes including protein translocases and respiratory chain supercomplexes. Negatively charged phospholipids such as cardiolipin are important for the architecture of the membranes and recruit soluble factors to the membranes to support mitochondrial dynamics. Thus, phospholipids not only form the hydrophobic core of biological membranes that surround mitochondria, but also create a specific environment to promote functions of various protein machineries. This article is part of a Special Issue entitled: Lipids of Mitochondria edited by Guenther Daum.
Collapse
|