1
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Wisniewski BT, Lackner LL. Significantly reduced, but balanced, rates of mitochondrial fission and fusion are sufficient to maintain the integrity of yeast mitochondrial DNA. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.18.604121. [PMID: 39071310 PMCID: PMC11275889 DOI: 10.1101/2024.07.18.604121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
Mitochondria exist as dynamic tubular networks and the morphology of these networks impacts organelle function and cell health. Mitochondrial morphology is maintained in part by the opposing activities of mitochondrial fission and fusion. Mitochondrial fission and fusion are also required to maintain mitochondrial DNA (mtDNA) integrity. In Saccharomyces cerevisiae , the simultaneous inhibition of mitochondrial fission and fusion results in increased mtDNA mutation and the consequent loss of respiratory competence. The mechanism by which fission and fusion maintain mtDNA integrity is not fully understood. Previous work demonstrates that mtDNA is spatially linked to mitochondrial fission sites. Here, we extend this finding using live-cell imaging to localize mtDNA to mitochondrial fusion sites. While mtDNA is present at sites of mitochondrial fission and fusion, mitochondrial fission and fusion rates are not altered in cells lacking mtDNA. Using alleles that alter mitochondrial fission and fusion rates, we find that mtDNA integrity can be maintained in cells with significantly reduced, but balanced, rates of fission and fusion. In addition, we find that increasing mtDNA copy number reduces the loss of respiratory competence in double mitochondrial fission-fusion mutants. Our findings add novel insights into the relationship between mitochondrial dynamics and mtDNA integrity.
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2
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Chen J, Shao J, Wang Y, Wu K, Huang M. OPA1, a molecular regulator of dilated cardiomyopathy. J Cell Mol Med 2023; 27:3017-3025. [PMID: 37603376 PMCID: PMC10568666 DOI: 10.1111/jcmm.17918] [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: 06/01/2023] [Revised: 08/08/2023] [Accepted: 08/11/2023] [Indexed: 08/22/2023] Open
Abstract
Dilated cardiomyopathy (DCM) is a disease with no specific treatment, poor prognosis and high mortality. During DCM development, there is apoptosis, mitochondrial dynamics imbalance and changes in cristae structure. Optic atrophy 1 (OPA1) appears at high frequency in these three aspects. DCM LMNA (LaminA/C) gene mutation can activate TP53, and the study of P53 shows that P53 affects OPA1 through Bak/Bax and OMA1 (a metalloprotease). OPA1 can be considered the missing link between DCMp53 and DCM apoptosis, mitochondrial dynamics imbalance and changes in cristae structure. OPA1 regulates apoptosis by regulating the release of cytochrome c from the mitochondrial matrix through CJs (crisp linkages, located in the inner mitochondrial membrane) and unbalances mitochondrial fusion and fission by affecting mitochondrial inner membrane (IM) fusion. OPA1 is also associated with the formation and maintenance of mitochondrial cristae. OPA1 is not the root cause of DCM, but it is an essential mediator in P53 mediating the occurrence and development of DCM, so OPA1 also becomes a molecular regulator of DCM. This review discusses the implication of OPA1 for DCM from three aspects: apoptosis, mitochondrial dynamics and ridge structure.
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Affiliation(s)
- Jiaqi Chen
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical UniversityWenzhouChina
| | - Jianan Shao
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical UniversityWenzhouChina
| | - Yaoyao Wang
- Fuwai HospitalChinese Academy of Medical Sciences & Peking Union Medical College/National Center for Cardiovascular DiseasesBeijingChina
| | - Kangxiang Wu
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical UniversityWenzhouChina
| | - Mingyuan Huang
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical UniversityWenzhouChina
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3
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Magistrati M, Gilea AI, Gerra MC, Baruffini E, Dallabona C. Drug Drop Test: How to Quickly Identify Potential Therapeutic Compounds for Mitochondrial Diseases Using Yeast Saccharomyces cerevisiae. Int J Mol Sci 2023; 24:10696. [PMID: 37445873 DOI: 10.3390/ijms241310696] [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: 05/30/2023] [Revised: 06/22/2023] [Accepted: 06/25/2023] [Indexed: 07/15/2023] Open
Abstract
Mitochondrial diseases (MDs) refer to a group of clinically and genetically heterogeneous pathologies characterized by defective mitochondrial function and energy production. Unfortunately, there is no effective treatment for most MDs, and current therapeutic management is limited to relieving symptoms. The yeast Saccharomyces cerevisiae has been efficiently used as a model organism to study mitochondria-related disorders thanks to its easy manipulation and well-known mitochondrial biogenesis and metabolism. It has been successfully exploited both to validate alleged pathogenic variants identified in patients and to discover potential beneficial molecules for their treatment. The so-called "drug drop test", a phenotype-based high-throughput screening, especially if coupled with a drug repurposing approach, allows the identification of molecules with high translational potential in a cost-effective and time-saving manner. In addition to drug identification, S. cerevisiae can be used to point out the drug's target or pathway. To date, drug drop tests have been successfully carried out for a variety of disease models, leading to very promising results. The most relevant aspect is that studies on more complex model organisms confirmed the effectiveness of the drugs, strengthening the results obtained in yeast and demonstrating the usefulness of this screening as a novel approach to revealing new therapeutic molecules for MDs.
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Affiliation(s)
- Martina Magistrati
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43124 Parma, Italy
| | - Alexandru Ionut Gilea
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43124 Parma, Italy
| | - Maria Carla Gerra
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43124 Parma, Italy
| | - Enrico Baruffini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43124 Parma, Italy
| | - Cristina Dallabona
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43124 Parma, Italy
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4
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Wu NS, Lin YF, Ma IC, Ko HJ, Hong YR. Many faces and functions of GSKIP: a temporospatial regulation view. Cell Signal 2022; 97:110391. [PMID: 35728705 DOI: 10.1016/j.cellsig.2022.110391] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 06/06/2022] [Accepted: 06/16/2022] [Indexed: 11/25/2022]
Abstract
Glycogen synthase kinase 3 (GSK3)-β (GSK3β) interaction protein (GSKIP) is one of the smallest A-kinase anchoring proteins that possesses a binding site for GSK3β. Recently, our group identified the protein kinase A (PKA)-GSKIP-GSK3β-X axis; knowledge of this axis may help us decipher the many roles of GSKIP and perhaps help explain the evolutionary reason behind the interaction between GSK3β and PKA. In this review, we highlight the critical and multifaceted role of GSKIP in facilitating PKA kinase activity and its function as a scaffolding protein in signaling pathways. We also highlight how these pivotal PKA and GSK3 kinases can control context-specific functions and interact with multiple target proteins, such as β-catenin, Drp1, Tau, and other proteins. GSKIP is a key regulator of multiple mechanisms because of not only its location at certain subcellular compartments but also its serial changes during the developmental process. Moreover, the involvement of critical upstream regulatory signaling pathways in GSKIP signaling in various cancers, such as miRNA (microRNA) and lncRNA (long noncoding RNA), may help in the identification of therapeutic targets in the era of precision medicine and personalized therapy. Finally, we emphasize on the model of the early stage of pathogenesis of Alzheimer Disease (AD). Although the model requires validation, it can serve as a basis for diagnostic biomarkers development and drug discovery for early-stage AD.
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Affiliation(s)
- Nian-Siou Wu
- School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
| | - Yi-Fan Lin
- School of Medicine, College of Medicine, National Taiwan University, Taipei 100, Taiwan.
| | - I Chu Ma
- China Medical University Hospital, Taichung 404, Taiwan.
| | - Huey-Jiun Ko
- Department of Biochemistry, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
| | - Yi-Ren Hong
- Department of Biochemistry, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan; Graduate Institutes of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan; Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan; Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan; Center for Cancer Research, Kaohsiung Medical University, Kaohsiung 807, Taiwan,; Neuroscience Research Center, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
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5
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Abstract
Mitochondria are complex organelles with two membranes. Their architecture is determined by characteristic folds of the inner membrane, termed cristae. Recent studies in yeast and other organisms led to the identification of four major pathways that cooperate to shape cristae membranes. These include dimer formation of the mitochondrial ATP synthase, assembly of the mitochondrial contact site and cristae organizing system (MICOS), inner membrane remodelling by a dynamin-related GTPase (Mgm1/OPA1), and modulation of the mitochondrial lipid composition. In this review, we describe the function of the evolutionarily conserved machineries involved in mitochondrial cristae biogenesis with a focus on yeast and present current models to explain how their coordinated activities establish mitochondrial membrane architecture.
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Affiliation(s)
- Till Klecker
- Institut für Zellbiologie, Universität Bayreuth, 95440 Bayreuth, Germany
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6
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Saccharomyces cerevisiae as a Tool for Studying Mutations in Nuclear Genes Involved in Diseases Caused by Mitochondrial DNA Instability. Genes (Basel) 2021; 12:genes12121866. [PMID: 34946817 PMCID: PMC8701800 DOI: 10.3390/genes12121866] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/20/2021] [Accepted: 11/23/2021] [Indexed: 01/03/2023] Open
Abstract
Mitochondrial DNA (mtDNA) maintenance is critical for oxidative phosphorylation (OXPHOS) since some subunits of the respiratory chain complexes are mitochondrially encoded. Pathological mutations in nuclear genes involved in the mtDNA metabolism may result in a quantitative decrease in mtDNA levels, referred to as mtDNA depletion, or in qualitative defects in mtDNA, especially in multiple deletions. Since, in the last decade, most of the novel mutations have been identified through whole-exome sequencing, it is crucial to confirm the pathogenicity by functional analysis in the appropriate model systems. Among these, the yeast Saccharomyces cerevisiae has proved to be a good model for studying mutations associated with mtDNA instability. This review focuses on the use of yeast for evaluating the pathogenicity of mutations in six genes, MPV17/SYM1, MRM2/MRM2, OPA1/MGM1, POLG/MIP1, RRM2B/RNR2, and SLC25A4/AAC2, all associated with mtDNA depletion or multiple deletions. We highlight the techniques used to construct a specific model and to measure the mtDNA instability as well as the main results obtained. We then report the contribution that yeast has given in understanding the pathogenic mechanisms of the mutant variants, in finding the genetic suppressors of the mitochondrial defects and in the discovery of molecules able to improve the mtDNA stability.
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7
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Shvetsova A, Masud AJ, Schneider L, Bergmann U, Monteuuis G, Miinalainen IJ, Hiltunen JK, Kastaniotis AJ. A hunt for OM45 synthetic petite interactions in Saccharomyces cerevisiae reveals a role for Miro GTPase Gem1p in cristae structure maintenance. Microbiologyopen 2021; 10:e1238. [PMID: 34713605 PMCID: PMC8501180 DOI: 10.1002/mbo3.1238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 09/09/2021] [Accepted: 09/09/2021] [Indexed: 11/28/2022] Open
Abstract
Om45 is a major protein of the yeast's outer mitochondrial membrane under respiratory conditions. However, the cellular role of the protein has remained obscure. Previously, deletion mutant phenotypes have not been found, and clear amino acid sequence similarities that would allow inferring its functional role are not available. In this work, we describe synthetic petite mutants of GEM1 and UGO1 that depend on the presence of OM45 for respiratory growth, as well as the identification of several multicopy suppressors of the synthetic petite phenotypes. In the analysis of our mutants, we demonstrate that Om45p and Gem1p have a collaborative role in the maintenance of mitochondrial morphology, cristae structure, and mitochondrial DNA maintenance. A group of multicopy suppressors rescuing the synthetic lethal phenotypes of the mutants on non-fermentable carbon sources additionally supports this result. Our results imply that the synthetic petite phenotypes we observed are due to the disturbance of the inner mitochondrial membrane and point to this mitochondrial sub-compartment as the main target of action of Om45p, Ugo1p, and the yeast Miro GTPase Gem1p.
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Affiliation(s)
- Antonina Shvetsova
- Faculty of Biochemistry and Molecular Medicine and Biocenter OuluUniversity of OuluOuluFinland
| | - Ali J. Masud
- Faculty of Biochemistry and Molecular Medicine and Biocenter OuluUniversity of OuluOuluFinland
| | - Laura Schneider
- Faculty of Biochemistry and Molecular Medicine and Biocenter OuluUniversity of OuluOuluFinland
| | - Ulrich Bergmann
- Faculty of Biochemistry and Molecular Medicine and Biocenter OuluUniversity of OuluOuluFinland
| | - Geoffray Monteuuis
- Faculty of Biochemistry and Molecular Medicine and Biocenter OuluUniversity of OuluOuluFinland
- Present address:
Department of Biochemistry and Developmental BiologyUniversity of HelsinkiHelsinkiFinland
| | - Ilkka J. Miinalainen
- Faculty of Biochemistry and Molecular Medicine and Biocenter OuluUniversity of OuluOuluFinland
| | - J. Kalervo Hiltunen
- Faculty of Biochemistry and Molecular Medicine and Biocenter OuluUniversity of OuluOuluFinland
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8
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The memory of neuronal mitochondrial stress is inherited transgenerationally via elevated mitochondrial DNA levels. Nat Cell Biol 2021; 23:870-880. [PMID: 34341532 DOI: 10.1038/s41556-021-00724-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 06/29/2021] [Indexed: 02/06/2023]
Abstract
The memory of stresses experienced by parents can be passed on to descendants as a forecast of the challenges to come. Here, we discovered that the neuronal mitochondrial perturbation-induced systemic mitochondrial unfolded protein response (UPRmt) in Caenorhabditis elegans can be transmitted to offspring over multiple generations. The transgenerational activation of UPRmt is mediated by maternal inheritance of elevated levels of mitochondrial DNA (mtDNA), which causes the proteostasis stress within mitochondria. Furthermore, results from intercrossing studies using wild C. elegans strains further support that maternal inheritance of higher levels of mtDNA can induce the UPRmt in descendants. The mitokine Wnt signalling pathway is required for the transmission of elevated mtDNA levels across generations, thereby conferring lifespan extension and stress resistance to offspring. Collectively, our results reveal that the nervous system can transmit stress signals across generations by increasing mtDNA in the germline, enabling descendants to better cope with anticipated challenges.
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9
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Del Dotto V, Carelli V. Dominant Optic Atrophy (DOA): Modeling the Kaleidoscopic Roles of OPA1 in Mitochondrial Homeostasis. Front Neurol 2021; 12:681326. [PMID: 34177786 PMCID: PMC8220150 DOI: 10.3389/fneur.2021.681326] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 04/22/2021] [Indexed: 02/05/2023] Open
Abstract
In the year 2000, the discovery of OPA1 mutations as causative for dominant optic atrophy (DOA) was pivotal to rapidly expand the field of mitochondrial dynamics and describe the complex machinery governing this pathway, with a multitude of other genes and encoded proteins involved in neurodegenerative disorders of the optic nerve. OPA1 turned out to be a much more complex protein than initially envisaged, connecting multiple pathways beyond its strict role in mitochondrial fusion, such as sensing of OXPHOS needs and mitochondrial DNA maintenance. As a consequence, an increasing need to investigate OPA1 functions at multiple levels has imposed the development of multiple tools and models that are here reviewed. Translational mitochondrial medicine, with the ultimate objective of translating basic science necessary to understand pathogenic mechanisms into therapeutic strategies, requires disease modeling at multiple levels: from the simplest, like in yeast, to cell models, including the increasing use of reprogrammed stem cells (iPSCs) from patients, to animal models. In the present review, we thoroughly examine and provide the state of the art of all these approaches.
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Affiliation(s)
- Valentina Del Dotto
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Valerio Carelli
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.,Istituto di Ricovero e Cura a Carattere Scientifico Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
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10
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Tarasenko D, Meinecke M. Protein-dependent membrane remodeling in mitochondrial morphology and clathrin-mediated endocytosis. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2021; 50:295-306. [PMID: 33527201 PMCID: PMC8071792 DOI: 10.1007/s00249-021-01501-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 01/04/2021] [Accepted: 01/13/2021] [Indexed: 11/30/2022]
Abstract
Cellular membranes can adopt a plethora of complex and beautiful shapes, most of which are believed to have evolved for a particular physiological reason. The closely entangled relationship between membrane morphology and cellular physiology is strikingly seen in membrane trafficking pathways. During clathrin-mediated endocytosis, for example, over the course of a minute, a patch of the more or less flat plasma membrane is remodeled into a highly curved clathrin-coated vesicle. Such vesicles are internalized by the cell to degrade or recycle plasma membrane receptors or to take up extracellular ligands. Other, steadier, membrane morphologies can be observed in organellar membranes like the endoplasmic reticulum or mitochondria. In the case of mitochondria, which are double membrane-bound, ubiquitous organelles of eukaryotic cells, especially the mitochondrial inner membrane displays an intricated ultrastructure. It is highly folded and consequently has a much larger surface than the mitochondrial outer membrane. It can adopt different shapes in response to cellular demands and changes of the inner membrane morphology often accompany severe diseases, including neurodegenerative- and metabolic diseases and cancer. In recent years, progress was made in the identification of molecules that are important for the aforementioned membrane remodeling events. In this review, we will sum up recent results and discuss the main players of membrane remodeling processes that lead to the mitochondrial inner membrane ultrastructure and in clathrin-mediated endocytosis. We will compare differences and similarities between the molecular mechanisms that peripheral and integral membrane proteins use to deform membranes.
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Affiliation(s)
- Daryna Tarasenko
- Department of Cellular Biochemistry, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany
| | - Michael Meinecke
- Department of Cellular Biochemistry, University Medical Center Göttingen, Humboldtallee 23, 37073, Göttingen, Germany.
- Göttinger Zentrum für Molekulare Biowissenschaften - GZMB, 37077, Göttingen, Germany.
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11
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Ceccatelli Berti C, di Punzio G, Dallabona C, Baruffini E, Goffrini P, Lodi T, Donnini C. The Power of Yeast in Modelling Human Nuclear Mutations Associated with Mitochondrial Diseases. Genes (Basel) 2021; 12:300. [PMID: 33672627 PMCID: PMC7924180 DOI: 10.3390/genes12020300] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 12/17/2022] Open
Abstract
The increasing application of next generation sequencing approaches to the analysis of human exome and whole genome data has enabled the identification of novel variants and new genes involved in mitochondrial diseases. The ability of surviving in the absence of oxidative phosphorylation (OXPHOS) and mitochondrial genome makes the yeast Saccharomyces cerevisiae an excellent model system for investigating the role of these new variants in mitochondrial-related conditions and dissecting the molecular mechanisms associated with these diseases. The aim of this review was to highlight the main advantages offered by this model for the study of mitochondrial diseases, from the validation and characterisation of novel mutations to the dissection of the role played by genes in mitochondrial functionality and the discovery of potential therapeutic molecules. The review also provides a summary of the main contributions to the understanding of mitochondrial diseases emerged from the study of this simple eukaryotic organism.
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Affiliation(s)
| | | | | | | | | | | | - Claudia Donnini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43124 Parma, Italy; (C.C.B.); (G.d.P.); (C.D.); (E.B.); (P.G.); (T.L.)
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12
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Aleo SJ, Del Dotto V, Fogazza M, Maresca A, Lodi T, Goffrini P, Ghelli A, Rugolo M, Carelli V, Baruffini E, Zanna C. Drug repositioning as a therapeutic strategy for neurodegenerations associated with OPA1 mutations. Hum Mol Genet 2020; 29:3631-3645. [PMID: 33231680 PMCID: PMC7823107 DOI: 10.1093/hmg/ddaa244] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 10/19/2020] [Accepted: 10/30/2020] [Indexed: 12/15/2022] Open
Abstract
OPA1 mutations are the major cause of dominant optic atrophy (DOA) and the syndromic form DOA plus, pathologies for which there is no established cure. We used a ‘drug repurposing’ approach to identify FDA-approved molecules able to rescue the mitochondrial dysfunctions induced by OPA1 mutations. We screened two different chemical libraries by using two yeast strains carrying the mgm1I322M and the chim3P646L mutations, identifying 26 drugs able to rescue their oxidative growth phenotype. Six of them, able to reduce the mitochondrial DNA instability in yeast, have been then tested in Opa1 deleted mouse embryonic fibroblasts expressing the human OPA1 isoform 1 bearing the R445H and D603H mutations. Some of these molecules were able to ameliorate the energetic functions and/or the mitochondrial network morphology, depending on the type of OPA1 mutation. The final validation has been performed in patients’ fibroblasts, allowing to select the most effective molecules. Our current results are instrumental to rapidly translating the findings of this drug repurposing approach into clinical trial for DOA and other neurodegenerations caused by OPA1 mutations.
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Affiliation(s)
- Serena J Aleo
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Bologna 40126, Italy
| | - Valentina Del Dotto
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna 40139, Italy
| | - Mario Fogazza
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Bologna 40126, Italy
| | - Alessandra Maresca
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna 40139, Italy
| | - Tiziana Lodi
- Department of Chemistry, Life Science and Environmental Sustainability, University of Parma, Parma 43124, Italy
| | - Paola Goffrini
- Department of Chemistry, Life Science and Environmental Sustainability, University of Parma, Parma 43124, Italy
| | - Anna Ghelli
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Bologna 40126, Italy
| | - Michela Rugolo
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Bologna 40126, Italy
| | - Valerio Carelli
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna 40139, Italy.,IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna 40139, Italy
| | - Enrico Baruffini
- Department of Chemistry, Life Science and Environmental Sustainability, University of Parma, Parma 43124, Italy
| | - Claudia Zanna
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Bologna 40126, Italy
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13
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Colina-Tenorio L, Horten P, Pfanner N, Rampelt H. Shaping the mitochondrial inner membrane in health and disease. J Intern Med 2020; 287:645-664. [PMID: 32012363 DOI: 10.1111/joim.13031] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 12/19/2019] [Accepted: 01/20/2020] [Indexed: 12/16/2022]
Abstract
Mitochondria play central roles in cellular energetics, metabolism and signalling. Efficient respiration, mitochondrial quality control, apoptosis and inheritance of mitochondrial DNA depend on the proper architecture of the mitochondrial membranes and a dynamic remodelling of inner membrane cristae. Defects in mitochondrial architecture can result in severe human diseases affecting predominantly the nervous system and the heart. Inner membrane morphology is generated and maintained in particular by the mitochondrial contact site and cristae organizing system (MICOS), the F1 Fo -ATP synthase, the fusion protein OPA1/Mgm1 and the nonbilayer-forming phospholipids cardiolipin and phosphatidylethanolamine. These protein complexes and phospholipids are embedded in a network of functional interactions. They communicate with each other and additional factors, enabling them to balance different aspects of cristae biogenesis and to dynamically remodel the inner mitochondrial membrane. Genetic alterations disturbing these membrane-shaping factors can lead to human pathologies including fatal encephalopathy, dominant optic atrophy, Leigh syndrome, Parkinson's disease and Barth syndrome.
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Affiliation(s)
- L Colina-Tenorio
- From the, Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - P Horten
- From the, Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - N Pfanner
- From the, Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - H Rampelt
- From the, Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
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14
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Khosravi S, Harner ME. The MICOS complex, a structural element of mitochondria with versatile functions. Biol Chem 2020; 401:765-778. [DOI: 10.1515/hsz-2020-0103] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 03/16/2020] [Indexed: 01/01/2023]
Abstract
AbstractMitochondria perform a plethora of functions in various cells of different tissues. Their architecture differs remarkably, for instance in neurons versus steroidogenic cells. Furthermore, aberrant mitochondrial architecture results in mitochondrial dysfunction. This indicates strongly that mitochondrial architecture and function are intimately linked. Therefore, a deep knowledge about the determinants of mitochondrial architecture and their function on a molecular level is of utmost importance. In the past decades, various proteins and protein complexes essential for formation of mitochondrial architecture have been identified. Here we will review the current knowledge of the MICOS complex, one of the major structural elements of mitochondria. MICOS is a multi-subunit complex present in the inner mitochondrial membrane. Multiple interaction partners in the inner and outer mitochondrial membrane point to participation in a multitude of important processes, such as generation of mitochondrial architecture, lipid metabolism, and protein import into mitochondria. Since the MICOS complex is highly conserved in form and function throughout evolution, we will highlight the importance of MICOS for mammals. We will emphasize in particular the current knowledge of the association of MICOS with severe human diseases, including Charcot–Marie–Tooth disease type 2, Alzheimer's disease, Parkinson's disease, Frontotemporal Dementia and Amyotrophic Lateral Sclerosis.
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Affiliation(s)
- Siavash Khosravi
- Department of Cell Biology, Biomedical Center, Ludwig-Maximilians University Munich, Großhaderner Str. 9, Planegg/Martinsried, MunichD-82152, Germany
| | - Max E. Harner
- Institute of Cardiovascular Physiology and Pathophysiology, Biomedical Center, Ludwig-Maximilians University Munich, Großhaderner Str. 9, Planegg/Martinsried, MunichD-82152, Germany
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15
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The Role of Reactive Oxygen Species in the Life Cycle of the Mitochondrion. Int J Mol Sci 2020; 21:ijms21062173. [PMID: 32245255 PMCID: PMC7139706 DOI: 10.3390/ijms21062173] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/12/2020] [Accepted: 03/19/2020] [Indexed: 02/07/2023] Open
Abstract
Currently, it is known that, in living systems, free radicals and other reactive oxygen and nitrogen species play a double role, because they can cause oxidative damage and tissue dysfunction and serve as molecular signals activating stress responses that are beneficial to the organism. It is also known that mitochondria, because of their capacity to produce free radicals, play a major role in tissue oxidative damage and dysfunction and provide protection against excessive tissue dysfunction through several mechanisms, including the stimulation of permeability transition pore opening. This process leads to mitoptosis and mitophagy, two sequential processes that are a universal route of elimination of dysfunctional mitochondria and is essential to protect cells from the harm due to mitochondrial disordered metabolism. To date, there is significant evidence not only that the above processes are induced by enhanced reactive oxygen species (ROS) production, but also that such production is involved in the other phases of the mitochondrial life cycle. Accumulating evidence also suggests that these effects are mediated through the regulation of the expression and the activity of proteins that are engaged in processes such as genesis, fission, fusion, and removal of mitochondria. This review provides an account of the developments of the knowledge on the dynamics of the mitochondrial population, examining the mechanisms governing their genesis, life, and death, and elucidating the role played by free radicals in such processes.
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16
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Structural analysis of a trimeric assembly of the mitochondrial dynamin-like GTPase Mgm1. Proc Natl Acad Sci U S A 2020; 117:4061-4070. [PMID: 32041880 PMCID: PMC7049166 DOI: 10.1073/pnas.1919116117] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Mitochondria are dynamic double-membraned organelles, which undergo cycles of division and fusion mediated by dynamin-related GTPases. How dynamins mediate mitochondrial inner membrane fusion is not understood. In humans, defective inner membrane fusion causes a degenerative form of blindness termed dominant optic atrophy. Here, we solve the structure of a trimer assembly of an inner membrane fusion dynamin. Our observations underscore the structural plasticity of dynamins and suggest a previously unidentified mode of how they might mediate membrane fusion events. The fusion of inner mitochondrial membranes requires dynamin-like GTPases, Mgm1 in yeast and OPA1 in mammals, but how they mediate membrane fusion is poorly understood. Here, we determined the crystal structure of Saccharomyces cerevisiae short Mgm1 (s-Mgm1) in complex with GDP. It revealed an N-terminal GTPase (G) domain followed by two helix bundles (HB1 and HB2) and a unique C-terminal lipid-interacting stalk (LIS). Dimers can form through antiparallel HB interactions. Head-to-tail trimers are built by intermolecular interactions between the G domain and HB2-LIS. Biochemical and in vivo analyses support the idea that the assembly interfaces observed here are native and critical for Mgm1 function. We also found that s-Mgm1 interacts with negatively charged lipids via both the G domain and LIS. Based on these observations, we propose that membrane targeting via the G domain and LIS facilitates the in cis assembly of Mgm1, potentially generating a highly curved membrane tip to allow inner membrane fusion.
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17
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Kulek AR, Anzell A, Wider JM, Sanderson TH, Przyklenk K. Mitochondrial Quality Control: Role in Cardiac Models of Lethal Ischemia-Reperfusion Injury. Cells 2020; 9:cells9010214. [PMID: 31952189 PMCID: PMC7016592 DOI: 10.3390/cells9010214] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 01/10/2020] [Accepted: 01/12/2020] [Indexed: 02/07/2023] Open
Abstract
The current standard of care for acute myocardial infarction or 'heart attack' is timely restoration of blood flow to the ischemic region of the heart. While reperfusion is essential for the salvage of ischemic myocardium, re-introduction of blood flow paradoxically kills (rather than rescues) a population of previously ischemic cardiomyocytes-a phenomenon referred to as 'lethal myocardial ischemia-reperfusion (IR) injury'. There is long-standing and exhaustive evidence that mitochondria are at the nexus of lethal IR injury. However, during the past decade, the paradigm of mitochondria as mediators of IR-induced cardiomyocyte death has been expanded to include the highly orchestrated process of mitochondrial quality control. Our aims in this review are to: (1) briefly summarize the current understanding of the pathogenesis of IR injury, and (2) incorporating landmark data from a broad spectrum of models (including immortalized cells, primary cardiomyocytes and intact hearts), provide a critical discussion of the emerging concept that mitochondrial dynamics and mitophagy (the components of mitochondrial quality control) may contribute to the pathogenesis of cardiomyocyte death in the setting of ischemia-reperfusion.
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Affiliation(s)
- Andrew R. Kulek
- Cardiovascular Research Institute, Wayne State University School of Medicine, Detroit, MI 48201, USA; (A.R.K.); (A.A.); (T.H.S.)
- Department of Biochemistry, Microbiology and Immunology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Anthony Anzell
- Cardiovascular Research Institute, Wayne State University School of Medicine, Detroit, MI 48201, USA; (A.R.K.); (A.A.); (T.H.S.)
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
- Departments of Emergency Medicine and Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48109, USA;
| | - Joseph M. Wider
- Departments of Emergency Medicine and Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48109, USA;
| | - Thomas H. Sanderson
- Cardiovascular Research Institute, Wayne State University School of Medicine, Detroit, MI 48201, USA; (A.R.K.); (A.A.); (T.H.S.)
- Departments of Emergency Medicine and Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48109, USA;
| | - Karin Przyklenk
- Cardiovascular Research Institute, Wayne State University School of Medicine, Detroit, MI 48201, USA; (A.R.K.); (A.A.); (T.H.S.)
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
- Department of Emergency Medicine, Wayne State University School of Medicine, Detroit, MI 48201, USA
- Correspondence: ; Tel.: +1-313-577-9047
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18
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Chua SCJH, Tan HQ, Engelberg D, Lim LHK. Alternative Experimental Models for Studying Influenza Proteins, Host-Virus Interactions and Anti-Influenza Drugs. Pharmaceuticals (Basel) 2019; 12:E147. [PMID: 31575020 PMCID: PMC6958409 DOI: 10.3390/ph12040147] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 09/11/2019] [Accepted: 09/12/2019] [Indexed: 12/14/2022] Open
Abstract
Ninety years after the discovery of the virus causing the influenza disease, this malady remains one of the biggest public health threats to mankind. Currently available drugs and vaccines only partially reduce deaths and hospitalizations. Some of the reasons for this disturbing situation stem from the sophistication of the viral machinery, but another reason is the lack of a complete understanding of the molecular and physiological basis of viral infections and host-pathogen interactions. Even the functions of the influenza proteins, their mechanisms of action and interaction with host proteins have not been fully revealed. These questions have traditionally been studied in mammalian animal models, mainly ferrets and mice (as well as pigs and non-human primates) and in cell lines. Although obviously relevant as models to humans, these experimental systems are very complex and are not conveniently accessible to various genetic, molecular and biochemical approaches. The fact that influenza remains an unsolved problem, in combination with the limitations of the conventional experimental models, motivated increasing attempts to use the power of other models, such as low eukaryotes, including invertebrate, and primary cell cultures. In this review, we summarized the efforts to study influenza in yeast, Drosophila, zebrafish and primary human tissue cultures and the major contributions these studies have made toward a better understanding of the disease. We feel that these models are still under-utilized and we highlight the unique potential each model has for better comprehending virus-host interactions and viral protein function.
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Affiliation(s)
- Sonja C J H Chua
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117593, Singapore.
- NUS Immunology Program, Life Sciences Institute, National University of Singapore, Singapore 117456, Singapore.
- CREATE-NUS-HUJ Molecular Mechanisms of Inflammatory Diseases Programme, National University of Singapore, Singapore 138602, Singapore.
| | - Hui Qing Tan
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117593, Singapore.
- NUS Immunology Program, Life Sciences Institute, National University of Singapore, Singapore 117456, Singapore.
| | - David Engelberg
- CREATE-NUS-HUJ Molecular Mechanisms of Inflammatory Diseases Programme, National University of Singapore, Singapore 138602, Singapore.
- Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545, Singapore.
- Department of Biological Chemistry, The Institute of Life Science, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel.
| | - Lina H K Lim
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117593, Singapore.
- NUS Immunology Program, Life Sciences Institute, National University of Singapore, Singapore 117456, Singapore.
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19
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Kondadi AK, Anand R, Reichert AS. Functional Interplay between Cristae Biogenesis, Mitochondrial Dynamics and Mitochondrial DNA Integrity. Int J Mol Sci 2019; 20:ijms20174311. [PMID: 31484398 PMCID: PMC6747513 DOI: 10.3390/ijms20174311] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 08/30/2019] [Accepted: 08/30/2019] [Indexed: 12/11/2022] Open
Abstract
Mitochondria are vital cellular organelles involved in a plethora of cellular processes such as energy conversion, calcium homeostasis, heme biogenesis, regulation of apoptosis and ROS reactive oxygen species (ROS) production. Although they are frequently depicted as static bean-shaped structures, our view has markedly changed over the past few decades as many studies have revealed a remarkable dynamicity of mitochondrial shapes and sizes both at the cellular and intra-mitochondrial levels. Aberrant changes in mitochondrial dynamics and cristae structure are associated with ageing and numerous human diseases (e.g., cancer, diabetes, various neurodegenerative diseases, types of neuro- and myopathies). Another unique feature of mitochondria is that they harbor their own genome, the mitochondrial DNA (mtDNA). MtDNA exists in several hundreds to thousands of copies per cell and is arranged and packaged in the mitochondrial matrix in structures termed mt-nucleoids. Many human diseases are mechanistically linked to mitochondrial dysfunction and alteration of the number and/or the integrity of mtDNA. In particular, several recent studies identified remarkable and partly unexpected links between mitochondrial structure, fusion and fission dynamics, and mtDNA. In this review, we will provide an overview about these recent insights and aim to clarify how mitochondrial dynamics, cristae ultrastructure and mtDNA structure influence each other and determine mitochondrial functions.
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Affiliation(s)
- Arun Kumar Kondadi
- Institute of Biochemistry and Molecular Biology I, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany.
| | - Ruchika Anand
- Institute of Biochemistry and Molecular Biology I, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Andreas S Reichert
- Institute of Biochemistry and Molecular Biology I, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany.
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20
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Faelber K, Dietrich L, Noel JK, Wollweber F, Pfitzner AK, Mühleip A, Sánchez R, Kudryashev M, Chiaruttini N, Lilie H, Schlegel J, Rosenbaum E, Hessenberger M, Matthaeus C, Kunz S, von der Malsburg A, Noé F, Roux A, van der Laan M, Kühlbrandt W, Daumke O. Structure and assembly of the mitochondrial membrane remodelling GTPase Mgm1. Nature 2019; 571:429-433. [PMID: 31292547 DOI: 10.1038/s41586-019-1372-3] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 06/13/2019] [Indexed: 12/25/2022]
Abstract
Balanced fusion and fission are key for the proper function and physiology of mitochondria1,2. Remodelling of the mitochondrial inner membrane is mediated by the dynamin-like protein mitochondrial genome maintenance 1 (Mgm1) in fungi or the related protein optic atrophy 1 (OPA1) in animals3-5. Mgm1 is required for the preservation of mitochondrial DNA in yeast6, whereas mutations in the OPA1 gene in humans are a common cause of autosomal dominant optic atrophy-a genetic disorder that affects the optic nerve7,8. Mgm1 and OPA1 are present in mitochondria as a membrane-integral long form and a short form that is soluble in the intermembrane space. Yeast strains that express temperature-sensitive mutants of Mgm19,10 or mammalian cells that lack OPA1 display fragmented mitochondria11,12, which suggests that Mgm1 and OPA1 have an important role in inner-membrane fusion. Consistently, only the mitochondrial outer membrane-not the inner membrane-fuses in the absence of functional Mgm113. Mgm1 and OPA1 have also been shown to maintain proper cristae architecture10,14; for example, OPA1 prevents the release of pro-apoptotic factors by tightening crista junctions15. Finally, the short form of OPA1 localizes to mitochondrial constriction sites, where it presumably promotes mitochondrial fission16. How Mgm1 and OPA1 perform their diverse functions in membrane fusion, scission and cristae organization is at present unknown. Here we present crystal and electron cryo-tomography structures of Mgm1 from Chaetomium thermophilum. Mgm1 consists of a GTPase (G) domain, a bundle signalling element domain, a stalk, and a paddle domain that contains a membrane-binding site. Biochemical and cell-based experiments demonstrate that the Mgm1 stalk mediates the assembly of bent tetramers into helical filaments. Electron cryo-tomography studies of Mgm1-decorated lipid tubes and fluorescence microscopy experiments on reconstituted membrane tubes indicate how the tetramers assemble on positively or negatively curved membranes. Our findings convey how Mgm1 and OPA1 filaments dynamically remodel the mitochondrial inner membrane.
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Affiliation(s)
- Katja Faelber
- Crystallography, Max-Delbrück-Centrum for Molecular Medicine, Berlin, Germany.
| | - Lea Dietrich
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Jeffrey K Noel
- Crystallography, Max-Delbrück-Centrum for Molecular Medicine, Berlin, Germany
| | - Florian Wollweber
- Medical Biochemistry & Molecular Biology, Center for Molecular Signaling, PZMS, Saarland University Medical School, Homburg, Germany
| | | | - Alexander Mühleip
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Ricardo Sánchez
- Alexander von Humboldt - Sofja Kovalevskaja Research Group, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Misha Kudryashev
- Alexander von Humboldt - Sofja Kovalevskaja Research Group, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | | | - Hauke Lilie
- Institute of Biochemistry and Biotechnology, Section of Protein Biochemistry, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Jeanette Schlegel
- Crystallography, Max-Delbrück-Centrum for Molecular Medicine, Berlin, Germany
| | - Eva Rosenbaum
- Crystallography, Max-Delbrück-Centrum for Molecular Medicine, Berlin, Germany
| | - Manuel Hessenberger
- Crystallography, Max-Delbrück-Centrum for Molecular Medicine, Berlin, Germany
| | - Claudia Matthaeus
- Crystallography, Max-Delbrück-Centrum for Molecular Medicine, Berlin, Germany
| | - Séverine Kunz
- EM facility, Max-Delbrück-Centrum for Molecular Medicine, Berlin, Germany
| | - Alexander von der Malsburg
- Medical Biochemistry & Molecular Biology, Center for Molecular Signaling, PZMS, Saarland University Medical School, Homburg, Germany
| | - Frank Noé
- Institute for Mathematics, Freie Universität Berlin, Berlin, Germany
| | - Aurélien Roux
- Biochemistry Department, University of Geneva, Geneva, Switzerland
| | - Martin van der Laan
- Medical Biochemistry & Molecular Biology, Center for Molecular Signaling, PZMS, Saarland University Medical School, Homburg, Germany
| | - Werner Kühlbrandt
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany.
| | - Oliver Daumke
- Crystallography, Max-Delbrück-Centrum for Molecular Medicine, Berlin, Germany. .,Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany.
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21
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Silva Ramos E, Motori E, Brüser C, Kühl I, Yeroslaviz A, Ruzzenente B, Kauppila JHK, Busch JD, Hultenby K, Habermann BH, Jakobs S, Larsson NG, Mourier A. Mitochondrial fusion is required for regulation of mitochondrial DNA replication. PLoS Genet 2019; 15:e1008085. [PMID: 31170154 PMCID: PMC6553695 DOI: 10.1371/journal.pgen.1008085] [Citation(s) in RCA: 95] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 03/11/2019] [Indexed: 11/18/2022] Open
Abstract
Mitochondrial dynamics is an essential physiological process controlling mitochondrial content mixing and mobility to ensure proper function and localization of mitochondria at intracellular sites of high-energy demand. Intriguingly, for yet unknown reasons, severe impairment of mitochondrial fusion drastically affects mtDNA copy number. To decipher the link between mitochondrial dynamics and mtDNA maintenance, we studied mouse embryonic fibroblasts (MEFs) and mouse cardiomyocytes with disruption of mitochondrial fusion. Super-resolution microscopy revealed that loss of outer mitochondrial membrane (OMM) fusion, but not inner mitochondrial membrane (IMM) fusion, leads to nucleoid clustering. Remarkably, fluorescence in situ hybridization (FISH), bromouridine labeling in MEFs and assessment of mitochondrial transcription in tissue homogenates revealed that abolished OMM fusion does not affect transcription. Furthermore, the profound mtDNA depletion in mouse hearts lacking OMM fusion is not caused by defective integrity or increased mutagenesis of mtDNA, but instead we show that mitochondrial fusion is necessary to maintain the stoichiometry of the protein components of the mtDNA replisome. OMM fusion is necessary for proliferating MEFs to recover from mtDNA depletion and for the marked increase of mtDNA copy number during postnatal heart development. Our findings thus link OMM fusion to replication and distribution of mtDNA. Mammalian mitochondria contain multiple copies of the mitochondrial genome (mtDNA), which encodes genes that are essential for the oxidative phosphorylation system. An important feature of mtDNA is that it is evenly distributed throughout the mitochondrial network. Dynamin-related GTPase proteins help control the size and shape of mitochondria by fusion and fission events and are intimately linked to maintenance and distribution of mtDNA. Certain human mutations in mitofusin 2 (MFN2) and optic atrophy protein 1 (OPA1) cause disease phenotypes, such as peripheral neuropathy and optic atrophy, which are often also associated with mtDNA depletion. However, the mechanism whereby MFNs and OPA1 are involved in maintenance of mtDNA is unclear. In this study, we demonstrate that rapid mtDNA synthesis in proliferating tissue-culture cells or cardiomyocytes during post-natal heart development requires mitochondrial fusion. However, the absence of mitochondrial fusion in mouse heart is not associated with mtDNA integrity defects but instead affects the replication of mtDNA. These findings provide direct evidence for the importance of mitochondrial fusion in maintaining mtDNA replication.
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Affiliation(s)
- Eduardo Silva Ramos
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Elisa Motori
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Christian Brüser
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Inge Kühl
- Institute of Integrative Biology of the Cell (I2BC) UMR9198, CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Assa Yeroslaviz
- Computational Systems Biochemistry, Bioinformatics Core Facility, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Benedetta Ruzzenente
- INSERM U1163, Université Paris Descartes-Sorbonne Paris Cité, Institut Imagine, Paris, France
| | - Johanna H. K. Kauppila
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Jakob D. Busch
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Kjell Hultenby
- Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | | | - Stefan Jakobs
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Nils-Göran Larsson
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
- * E-mail: (NGL); (AM)
| | - Arnaud Mourier
- Université de Bordeaux, IBGC UMR 5095, Bordeaux, France
- CNRS, IBGC CNRS UMR 5095, Bordeaux, France
- * E-mail: (NGL); (AM)
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22
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Assembly of the complexes of oxidative phosphorylation triggers the remodeling of cardiolipin. Proc Natl Acad Sci U S A 2019; 116:11235-11240. [PMID: 31110016 DOI: 10.1073/pnas.1900890116] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Cardiolipin (CL) is a mitochondrial phospholipid with a very specific and functionally important fatty acid composition, generated by tafazzin. However, in vitro tafazzin catalyzes a promiscuous acyl exchange that acquires specificity only in response to perturbations of the physical state of lipids. To identify the process that imposes acyl specificity onto CL remodeling in vivo, we analyzed a series of deletions and knockdowns in Saccharomyces cerevisiae and Drosophila melanogaster, including carriers, membrane homeostasis proteins, fission-fusion proteins, cristae-shape controlling and MICOS proteins, and the complexes I-V. Among those, only the complexes of oxidative phosphorylation (OXPHOS) affected the CL composition. Rather than any specific complex, it was the global impairment of the OXPHOS system that altered CL and at the same time shortened its half-life. The knockdown of OXPHOS expression had the same effect on CL as the knockdown of tafazzin in Drosophila flight muscles, including a change in CL composition and the accumulation of monolyso-CL. Thus, the assembly of OXPHOS complexes induces CL remodeling, which, in turn, leads to CL stabilization. We hypothesize that protein crowding in the OXPHOS system imposes packing stress on the lipid bilayer, which is relieved by CL remodeling to form tightly packed lipid-protein complexes.
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23
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Delerue T, Tribouillard-Tanvier D, Daloyau M, Khosrobakhsh F, Emorine LJ, Friocourt G, Belenguer P, Blondel M, Arnauné-Pelloquin L. A yeast-based screening assay identifies repurposed drugs that suppress mitochondrial fusion and mtDNA maintenance defects. Dis Model Mech 2019; 12:dmm.036558. [PMID: 30658998 PMCID: PMC6398489 DOI: 10.1242/dmm.036558] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 01/04/2019] [Indexed: 12/17/2022] Open
Abstract
Mitochondria continually move, fuse and divide, and these dynamics are essential for the proper function of the organelles. Indeed, the dynamic balance of fusion and fission of mitochondria determines their morphology and allows their immediate adaptation to energetic needs as well as preserving their integrity. As a consequence, mitochondrial fusion and fission dynamics and the proteins that control these processes, which are conserved from yeast to human, are essential, and their disturbances are associated with severe human disorders, including neurodegenerative diseases. For example, mutations in OPA1, which encodes a conserved factor essential for mitochondrial fusion, lead to optic atrophy 1, a neurodegeneration that affects the optic nerve, eventually leading to blindness. Here, by screening a collection of ∼1600 repurposed drugs on a fission yeast model, we identified five compounds able to efficiently prevent the lethality associated with the loss of Msp1p, the fission yeast ortholog of OPA1. One compound, hexestrol, was able to rescue both the mitochondrial fragmentation and mitochondrial DNA (mtDNA) depletion induced by the loss of Msp1p, whereas the second, clomifene, only suppressed the mtDNA defect. Yeast has already been successfully used to identify candidate drugs to treat inherited mitochondrial diseases; this work may therefore provide useful leads for the treatment of optic atrophies such as optic atrophy 1 or Leber hereditary optic neuropathy.
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Affiliation(s)
- Thomas Delerue
- Research Center on Animal Cognition (CRCA) and Center of Developmental Biology (CBD), Center for Integrative Biology (CBI), Toulouse University, CNRS, UPS, 118 route de Narbonne, 31062 Toulouse, France
| | - Déborah Tribouillard-Tanvier
- Institut National de la Santé et de la Recherche Médicale UMR1078, Université de Bretagne Occidentale, Etablissement Français du Sang Bretagne, CHRU Brest, Hôpital Morvan, Laboratoire de Génétique Moléculaire, 29200 Brest, France.,Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, Université de Bordeaux, 1 rue Camille Saint-Saëns, 33077 Bordeaux, France
| | - Marlène Daloyau
- Research Center on Animal Cognition (CRCA) and Center of Developmental Biology (CBD), Center for Integrative Biology (CBI), Toulouse University, CNRS, UPS, 118 route de Narbonne, 31062 Toulouse, France
| | - Farnoosh Khosrobakhsh
- Research Center on Animal Cognition (CRCA) and Center of Developmental Biology (CBD), Center for Integrative Biology (CBI), Toulouse University, CNRS, UPS, 118 route de Narbonne, 31062 Toulouse, France
| | - Laurent Jean Emorine
- Research Center on Animal Cognition (CRCA) and Center of Developmental Biology (CBD), Center for Integrative Biology (CBI), Toulouse University, CNRS, UPS, 118 route de Narbonne, 31062 Toulouse, France
| | - Gaëlle Friocourt
- Institut National de la Santé et de la Recherche Médicale UMR1078, Université de Bretagne Occidentale, Etablissement Français du Sang Bretagne, CHRU Brest, Hôpital Morvan, Laboratoire de Génétique Moléculaire, 29200 Brest, France
| | - Pascale Belenguer
- Research Center on Animal Cognition (CRCA) and Center of Developmental Biology (CBD), Center for Integrative Biology (CBI), Toulouse University, CNRS, UPS, 118 route de Narbonne, 31062 Toulouse, France
| | - Marc Blondel
- Institut National de la Santé et de la Recherche Médicale UMR1078, Université de Bretagne Occidentale, Etablissement Français du Sang Bretagne, CHRU Brest, Hôpital Morvan, Laboratoire de Génétique Moléculaire, 29200 Brest, France
| | - Laetitia Arnauné-Pelloquin
- Research Center on Animal Cognition (CRCA) and Center of Developmental Biology (CBD), Center for Integrative Biology (CBI), Toulouse University, CNRS, UPS, 118 route de Narbonne, 31062 Toulouse, France
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24
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Larsson L, Degens H, Li M, Salviati L, Lee YI, Thompson W, Kirkland JL, Sandri M. Sarcopenia: Aging-Related Loss of Muscle Mass and Function. Physiol Rev 2019; 99:427-511. [PMID: 30427277 DOI: 10.1152/physrev.00061.2017] [Citation(s) in RCA: 767] [Impact Index Per Article: 153.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Sarcopenia is a loss of muscle mass and function in the elderly that reduces mobility, diminishes quality of life, and can lead to fall-related injuries, which require costly hospitalization and extended rehabilitation. This review focuses on the aging-related structural changes and mechanisms at cellular and subcellular levels underlying changes in the individual motor unit: specifically, the perikaryon of the α-motoneuron, its neuromuscular junction(s), and the muscle fibers that it innervates. Loss of muscle mass with aging, which is largely due to the progressive loss of motoneurons, is associated with reduced muscle fiber number and size. Muscle function progressively declines because motoneuron loss is not adequately compensated by reinnervation of muscle fibers by the remaining motoneurons. At the intracellular level, key factors are qualitative changes in posttranslational modifications of muscle proteins and the loss of coordinated control between contractile, mitochondrial, and sarcoplasmic reticulum protein expression. Quantitative and qualitative changes in skeletal muscle during the process of aging also have been implicated in the pathogenesis of acquired and hereditary neuromuscular disorders. In experimental models, specific intervention strategies have shown encouraging results on limiting deterioration of motor unit structure and function under conditions of impaired innervation. Translated to the clinic, if these or similar interventions, by saving muscle and improving mobility, could help alleviate sarcopenia in the elderly, there would be both great humanitarian benefits and large cost savings for health care systems.
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Affiliation(s)
- Lars Larsson
- Department of Physiology and Pharmacology, Basic and Clinical Muscle Biology Group, Karolinska Institutet , Stockholm , Sweden ; Section of Clinical Neurophysiology, Department of Clinical Neuroscience, Karolinska Institutet , Stockholm , Sweden ; Department of Biobehavioral Health, The Pennsylvania State University , University Park, Pennsylvania ; School of Healthcare Science, Metropolitan University , Manchester , United Kingdom ; Institute of Sport Science and Innovations, Lithuanian Sports University , Kaunas , Lithuania ; Clinical Genetics Unit, Department of Woman and Child Health, University of Padova , Padova , Italy ; IRP Città della Speranza, Padova , Italy ; Department of Biology, Texas A&M University , College Station, Texas ; Robert and Arlene Kogod Center on Aging, Mayo Clinic , Rochester, Minnesota ; Department of Biomedical Science, Venetian Institute of Molecular Medicine, University of Padova , Padova , Italy
| | - Hans Degens
- Department of Physiology and Pharmacology, Basic and Clinical Muscle Biology Group, Karolinska Institutet , Stockholm , Sweden ; Section of Clinical Neurophysiology, Department of Clinical Neuroscience, Karolinska Institutet , Stockholm , Sweden ; Department of Biobehavioral Health, The Pennsylvania State University , University Park, Pennsylvania ; School of Healthcare Science, Metropolitan University , Manchester , United Kingdom ; Institute of Sport Science and Innovations, Lithuanian Sports University , Kaunas , Lithuania ; Clinical Genetics Unit, Department of Woman and Child Health, University of Padova , Padova , Italy ; IRP Città della Speranza, Padova , Italy ; Department of Biology, Texas A&M University , College Station, Texas ; Robert and Arlene Kogod Center on Aging, Mayo Clinic , Rochester, Minnesota ; Department of Biomedical Science, Venetian Institute of Molecular Medicine, University of Padova , Padova , Italy
| | - Meishan Li
- Department of Physiology and Pharmacology, Basic and Clinical Muscle Biology Group, Karolinska Institutet , Stockholm , Sweden ; Section of Clinical Neurophysiology, Department of Clinical Neuroscience, Karolinska Institutet , Stockholm , Sweden ; Department of Biobehavioral Health, The Pennsylvania State University , University Park, Pennsylvania ; School of Healthcare Science, Metropolitan University , Manchester , United Kingdom ; Institute of Sport Science and Innovations, Lithuanian Sports University , Kaunas , Lithuania ; Clinical Genetics Unit, Department of Woman and Child Health, University of Padova , Padova , Italy ; IRP Città della Speranza, Padova , Italy ; Department of Biology, Texas A&M University , College Station, Texas ; Robert and Arlene Kogod Center on Aging, Mayo Clinic , Rochester, Minnesota ; Department of Biomedical Science, Venetian Institute of Molecular Medicine, University of Padova , Padova , Italy
| | - Leonardo Salviati
- Department of Physiology and Pharmacology, Basic and Clinical Muscle Biology Group, Karolinska Institutet , Stockholm , Sweden ; Section of Clinical Neurophysiology, Department of Clinical Neuroscience, Karolinska Institutet , Stockholm , Sweden ; Department of Biobehavioral Health, The Pennsylvania State University , University Park, Pennsylvania ; School of Healthcare Science, Metropolitan University , Manchester , United Kingdom ; Institute of Sport Science and Innovations, Lithuanian Sports University , Kaunas , Lithuania ; Clinical Genetics Unit, Department of Woman and Child Health, University of Padova , Padova , Italy ; IRP Città della Speranza, Padova , Italy ; Department of Biology, Texas A&M University , College Station, Texas ; Robert and Arlene Kogod Center on Aging, Mayo Clinic , Rochester, Minnesota ; Department of Biomedical Science, Venetian Institute of Molecular Medicine, University of Padova , Padova , Italy
| | - Young Il Lee
- Department of Physiology and Pharmacology, Basic and Clinical Muscle Biology Group, Karolinska Institutet , Stockholm , Sweden ; Section of Clinical Neurophysiology, Department of Clinical Neuroscience, Karolinska Institutet , Stockholm , Sweden ; Department of Biobehavioral Health, The Pennsylvania State University , University Park, Pennsylvania ; School of Healthcare Science, Metropolitan University , Manchester , United Kingdom ; Institute of Sport Science and Innovations, Lithuanian Sports University , Kaunas , Lithuania ; Clinical Genetics Unit, Department of Woman and Child Health, University of Padova , Padova , Italy ; IRP Città della Speranza, Padova , Italy ; Department of Biology, Texas A&M University , College Station, Texas ; Robert and Arlene Kogod Center on Aging, Mayo Clinic , Rochester, Minnesota ; Department of Biomedical Science, Venetian Institute of Molecular Medicine, University of Padova , Padova , Italy
| | - Wesley Thompson
- Department of Physiology and Pharmacology, Basic and Clinical Muscle Biology Group, Karolinska Institutet , Stockholm , Sweden ; Section of Clinical Neurophysiology, Department of Clinical Neuroscience, Karolinska Institutet , Stockholm , Sweden ; Department of Biobehavioral Health, The Pennsylvania State University , University Park, Pennsylvania ; School of Healthcare Science, Metropolitan University , Manchester , United Kingdom ; Institute of Sport Science and Innovations, Lithuanian Sports University , Kaunas , Lithuania ; Clinical Genetics Unit, Department of Woman and Child Health, University of Padova , Padova , Italy ; IRP Città della Speranza, Padova , Italy ; Department of Biology, Texas A&M University , College Station, Texas ; Robert and Arlene Kogod Center on Aging, Mayo Clinic , Rochester, Minnesota ; Department of Biomedical Science, Venetian Institute of Molecular Medicine, University of Padova , Padova , Italy
| | - James L Kirkland
- Department of Physiology and Pharmacology, Basic and Clinical Muscle Biology Group, Karolinska Institutet , Stockholm , Sweden ; Section of Clinical Neurophysiology, Department of Clinical Neuroscience, Karolinska Institutet , Stockholm , Sweden ; Department of Biobehavioral Health, The Pennsylvania State University , University Park, Pennsylvania ; School of Healthcare Science, Metropolitan University , Manchester , United Kingdom ; Institute of Sport Science and Innovations, Lithuanian Sports University , Kaunas , Lithuania ; Clinical Genetics Unit, Department of Woman and Child Health, University of Padova , Padova , Italy ; IRP Città della Speranza, Padova , Italy ; Department of Biology, Texas A&M University , College Station, Texas ; Robert and Arlene Kogod Center on Aging, Mayo Clinic , Rochester, Minnesota ; Department of Biomedical Science, Venetian Institute of Molecular Medicine, University of Padova , Padova , Italy
| | - Marco Sandri
- Department of Physiology and Pharmacology, Basic and Clinical Muscle Biology Group, Karolinska Institutet , Stockholm , Sweden ; Section of Clinical Neurophysiology, Department of Clinical Neuroscience, Karolinska Institutet , Stockholm , Sweden ; Department of Biobehavioral Health, The Pennsylvania State University , University Park, Pennsylvania ; School of Healthcare Science, Metropolitan University , Manchester , United Kingdom ; Institute of Sport Science and Innovations, Lithuanian Sports University , Kaunas , Lithuania ; Clinical Genetics Unit, Department of Woman and Child Health, University of Padova , Padova , Italy ; IRP Città della Speranza, Padova , Italy ; Department of Biology, Texas A&M University , College Station, Texas ; Robert and Arlene Kogod Center on Aging, Mayo Clinic , Rochester, Minnesota ; Department of Biomedical Science, Venetian Institute of Molecular Medicine, University of Padova , Padova , Italy
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25
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Harner ME, Unger AK, Geerts WJ, Mari M, Izawa T, Stenger M, Geimer S, Reggiori F, Westermann B, Neupert W. An evidence based hypothesis on the existence of two pathways of mitochondrial crista formation. eLife 2016; 5. [PMID: 27849155 PMCID: PMC5138035 DOI: 10.7554/elife.18853] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 11/14/2016] [Indexed: 12/31/2022] Open
Abstract
Metabolic function and architecture of mitochondria are intimately linked. More than 60 years ago, cristae were discovered as characteristic elements of mitochondria that harbor the protein complexes of oxidative phosphorylation, but how cristae are formed, remained an open question. Here we present experimental results obtained with yeast that support a novel hypothesis on the existence of two molecular pathways that lead to the generation of lamellar and tubular cristae. Formation of lamellar cristae depends on the mitochondrial fusion machinery through a pathway that is required also for homeostasis of mitochondria and mitochondrial DNA. Tubular cristae are formed via invaginations of the inner boundary membrane by a pathway independent of the fusion machinery. Dimerization of the F1FO-ATP synthase and the presence of the MICOS complex are necessary for both pathways. The proposed hypothesis is suggested to apply also to higher eukaryotes, since the key components are conserved in structure and function throughout evolution. DOI:http://dx.doi.org/10.7554/eLife.18853.001 Cells contain compartments called mitochondria, which are often called the powerhouses of the cell because they provide energy that drives vital cellular processes. Mitochondria have two membranes: an outer and an inner membrane. The outer membrane separates the mitochondria from the rest of the cell. The inner membrane is elaborately folded and the folds – called cristae – create a larger space to accommodate all of the protein machinery involved in producing energy. The cristae can be shaped as flat sac-like structures called lamellar cristae or as tubes known as tubular cristae. Mitochondria are dynamic and are constantly fusing with other mitochondria and splitting up. Even though the internal architecture of mitochondria was first revealed around 60 years ago, it is still not clear how the cristae form. Harner et al. now address this question in yeast cells by combining imaging, biochemistry and genetic approaches. The experiments show that lamellar cristae form when two mitochondria fuse with each other. The outer membranes merge and then the inner membranes start to fuse around their edges to generate the sac-like structure of lamellar cristae. A yeast protein called Mgm1 (known as Opa1 in mammals) drives the fusion of the inner membranes, but this process only takes place when enzymes called F1FO-ATP synthases on the inner membrane form pairs with one another. These F1FO-ATP synthase pairs stabilize the cristae membranes as they curve to form the sac-like structure. Later on, the formation of a group of proteins called the MICOS complex halts the fusion process to prevent the lamellar cristae from completely separating from the rest of the inner membrane. Harner et al. also found that tubular cristae form using a different mechanism when the inner membrane of the mitochondria grows inwards. This process also requires pairs of F1FO-ATP synthases and the MICOS complex, but does not involve Mgm1/Opa1. Together, these findings show that lamellar and tubular cristae in yeast form using two different mechanisms. Since the key components of these mechanisms are also found in virtually all other eukaryotes, the findings of Harner et al. are also likely to apply to many other organisms including animals. DOI:http://dx.doi.org/10.7554/eLife.18853.002
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Affiliation(s)
- Max E Harner
- Max Planck Institute of Biochemistry, Martinsried, Germany.,Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians-Universität München, Martinsried, Germany
| | - Ann-Katrin Unger
- Cell Biology and Electron Microscopy, Universität Bayreuth, Bayreuth, Germany
| | - Willie Jc Geerts
- Biomolecular Imaging, Bijvoet Center, Universiteit Utrecht, Utrecht, Netherlands
| | - Muriel Mari
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Toshiaki Izawa
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Maria Stenger
- Cell Biology and Electron Microscopy, Universität Bayreuth, Bayreuth, Germany
| | - Stefan Geimer
- Cell Biology and Electron Microscopy, Universität Bayreuth, Bayreuth, Germany
| | - Fulvio Reggiori
- Department of Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Benedikt Westermann
- Cell Biology and Electron Microscopy, Universität Bayreuth, Bayreuth, Germany
| | - Walter Neupert
- Max Planck Institute of Biochemistry, Martinsried, Germany.,Department of Anatomy and Cell Biology, Biomedical Center, Ludwig-Maximilians Universität München, Martinsried, Germany
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26
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Delerue T, Khosrobakhsh F, Daloyau M, Emorine LJ, Dedieu A, Herbert CJ, Bonnefoy N, Arnauné-Pelloquin L, Belenguer P. Loss of Msp1p in Schizosaccharomyces pombe induces a ROS-dependent nuclear mutator phenotype that affects mitochondrial fission genes. FEBS Lett 2016; 590:3544-3558. [PMID: 27664110 DOI: 10.1002/1873-3468.12432] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 06/29/2016] [Accepted: 08/31/2016] [Indexed: 01/12/2023]
Abstract
Mitochondria continually fuse and divide to dynamically adapt to changes in metabolism and stress. Mitochondrial dynamics are also required for mitochondrial DNA (mtDNA) integrity; however, the underlying reason is not known. In this study, we examined the link between mitochondrial fusion and mtDNA maintenance in Schizosaccharomyces pombe, which cannot survive without mtDNA, by screening for suppressors of the lethality induced by loss of the dynamin-related large GTPase Msp1p. Our findings reveal that inactivation of Msp1p induces a ROS-dependent nuclear mutator phenotype that affects mitochondrial fission genes involved in suppressing mitochondrial fragmentation and mtDNA depletion. This indicates that mitochondrial fusion is crucial for maintaining the integrity of both mitochondrial and nuclear genetic information. Furthermore, our study suggests that the primary roles of Msp1p are to organize mitochondrial membranes, thus making them competent for fusion, and maintain the integrity of mtDNA.
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Affiliation(s)
- Thomas Delerue
- Center of Developmental Biology (CBD) and Research Center on Animal Cognition (CRCA), Center for Integrative Biology (CBI), Toulouse University, CNRS, UPS, France
| | - Farnoosh Khosrobakhsh
- Center of Developmental Biology (CBD) and Research Center on Animal Cognition (CRCA), Center for Integrative Biology (CBI), Toulouse University, CNRS, UPS, France.,Department of Biological Science, Faculty of Science, University of Kurdistan, Sanandaj, Iran
| | - Marlène Daloyau
- Center of Developmental Biology (CBD) and Research Center on Animal Cognition (CRCA), Center for Integrative Biology (CBI), Toulouse University, CNRS, UPS, France
| | - Laurent Jean Emorine
- Center of Developmental Biology (CBD) and Research Center on Animal Cognition (CRCA), Center for Integrative Biology (CBI), Toulouse University, CNRS, UPS, France
| | - Adrien Dedieu
- Center of Developmental Biology (CBD) and Research Center on Animal Cognition (CRCA), Center for Integrative Biology (CBI), Toulouse University, CNRS, UPS, France
| | - Christopher J Herbert
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, University Paris-Sud, University Paris-Saclay, Gif-sur-Yvette Cedex, France
| | - Nathalie Bonnefoy
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, University Paris-Sud, University Paris-Saclay, Gif-sur-Yvette Cedex, France
| | - Laetitia Arnauné-Pelloquin
- Center of Developmental Biology (CBD) and Research Center on Animal Cognition (CRCA), Center for Integrative Biology (CBI), Toulouse University, CNRS, UPS, France
| | - Pascale Belenguer
- Center of Developmental Biology (CBD) and Research Center on Animal Cognition (CRCA), Center for Integrative Biology (CBI), Toulouse University, CNRS, UPS, France.
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27
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Patrushev MV, Mazunin IO, Vinogradova EN, Kamenski PA. Mitochondrial Fission and Fusion. BIOCHEMISTRY (MOSCOW) 2016; 80:1457-64. [PMID: 26615436 DOI: 10.1134/s0006297915110061] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Mitochondria are key cellular organelles responsible for many different functions. The molecular biology of mitochondria is continuously subject to comprehensive studies. However, detailed mechanisms of mitochondrial biogenesis are still unclear. Fusion and fission are among the most enigmatic processes connected with mitochondria. On the other hand, it has been shown that these events are of great biological importance for functioning of living cells. In this review, we summarize existing molecular data on mitochondrial dynamics and discuss possible biological functions of fusion and fission of these organelles.
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Affiliation(s)
- M V Patrushev
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119991, Russia.
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28
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Bioenergetic roles of mitochondrial fusion. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1277-1283. [DOI: 10.1016/j.bbabio.2016.04.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 03/18/2016] [Accepted: 04/05/2016] [Indexed: 11/17/2022]
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29
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Lasserre JP, Dautant A, Aiyar RS, Kucharczyk R, Glatigny A, Tribouillard-Tanvier D, Rytka J, Blondel M, Skoczen N, Reynier P, Pitayu L, Rötig A, Delahodde A, Steinmetz LM, Dujardin G, Procaccio V, di Rago JP. Yeast as a system for modeling mitochondrial disease mechanisms and discovering therapies. Dis Model Mech 2016; 8:509-26. [PMID: 26035862 PMCID: PMC4457039 DOI: 10.1242/dmm.020438] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Mitochondrial diseases are severe and largely untreatable. Owing to the many essential processes carried out by mitochondria and the complex cellular systems that support these processes, these diseases are diverse, pleiotropic, and challenging to study. Much of our current understanding of mitochondrial function and dysfunction comes from studies in the baker's yeast Saccharomyces cerevisiae. Because of its good fermenting capacity, S. cerevisiae can survive mutations that inactivate oxidative phosphorylation, has the ability to tolerate the complete loss of mitochondrial DNA (a property referred to as ‘petite-positivity’), and is amenable to mitochondrial and nuclear genome manipulation. These attributes make it an excellent model system for studying and resolving the molecular basis of numerous mitochondrial diseases. Here, we review the invaluable insights this model organism has yielded about diseases caused by mitochondrial dysfunction, which ranges from primary defects in oxidative phosphorylation to metabolic disorders, as well as dysfunctions in maintaining the genome or in the dynamics of mitochondria. Owing to the high level of functional conservation between yeast and human mitochondrial genes, several yeast species have been instrumental in revealing the molecular mechanisms of pathogenic human mitochondrial gene mutations. Importantly, such insights have pointed to potential therapeutic targets, as have genetic and chemical screens using yeast. Summary: In this Review, we discuss the use of budding yeast to understand mitochondrial diseases and help in the search for their treatments.
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Affiliation(s)
- Jean-Paul Lasserre
- University Bordeaux-CNRS, IBGC, UMR 5095, 1 rue Camille Saint-Saëns, Bordeaux F-33000, France
| | - Alain Dautant
- University Bordeaux-CNRS, IBGC, UMR 5095, 1 rue Camille Saint-Saëns, Bordeaux F-33000, France
| | - Raeka S Aiyar
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Meyerhofstrasse 1, Heidelberg 69117, Germany
| | - Roza Kucharczyk
- Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw 02-106, Poland
| | - Annie Glatigny
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Université Paris-Sud, 1 avenue de la terrasse, Gif-sur-Yvette 91198, France
| | - Déborah Tribouillard-Tanvier
- Institut National de la Santé et de la Recherche Médicale UMR1078, Université de Bretagne Occidentale, Faculté de Médecine et des Sciences de la Santé, Etablissement Français du Sang (EFS) Bretagne, CHRU Brest, Hôpital Morvan, Laboratoire de Génétique Moléculaire, Brest F-29200, France
| | - Joanna Rytka
- Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw 02-106, Poland
| | - Marc Blondel
- Institut National de la Santé et de la Recherche Médicale UMR1078, Université de Bretagne Occidentale, Faculté de Médecine et des Sciences de la Santé, Etablissement Français du Sang (EFS) Bretagne, CHRU Brest, Hôpital Morvan, Laboratoire de Génétique Moléculaire, Brest F-29200, France
| | - Natalia Skoczen
- University Bordeaux-CNRS, IBGC, UMR 5095, 1 rue Camille Saint-Saëns, Bordeaux F-33000, France Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw 02-106, Poland
| | - Pascal Reynier
- UMR CNRS 6214-INSERM U1083, Angers 49933, Cedex 9, France Département de Biochimie et Génétique, Centre Hospitalier Universitaire d'Angers, Angers 49933, Cedex 9, France
| | - Laras Pitayu
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Université Paris-Sud, rue Gregor Mendel, Orsay 91405, France
| | - Agnès Rötig
- Inserm U1163, Hôpital Necker-Enfants-Malades, Institut Imagine, Université Paris Descartes-Sorbonne Paris Cité, 149 rue de Sèvres, Paris 75015, France
| | - Agnès Delahodde
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Université Paris-Sud, rue Gregor Mendel, Orsay 91405, France
| | - Lars M Steinmetz
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Meyerhofstrasse 1, Heidelberg 69117, Germany Stanford Genome Technology Center, Department of Biochemistry, Stanford University, Palo Alto, CA 94304, USA Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305-5301, USA
| | - Geneviève Dujardin
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Université Paris-Sud, 1 avenue de la terrasse, Gif-sur-Yvette 91198, France
| | - Vincent Procaccio
- UMR CNRS 6214-INSERM U1083, Angers 49933, Cedex 9, France Département de Biochimie et Génétique, Centre Hospitalier Universitaire d'Angers, Angers 49933, Cedex 9, France
| | - Jean-Paul di Rago
- University Bordeaux-CNRS, IBGC, UMR 5095, 1 rue Camille Saint-Saëns, Bordeaux F-33000, France
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30
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Calzada E, Onguka O, Claypool SM. Phosphatidylethanolamine Metabolism in Health and Disease. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 321:29-88. [PMID: 26811286 DOI: 10.1016/bs.ircmb.2015.10.001] [Citation(s) in RCA: 255] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Phosphatidylethanolamine (PE) is the second most abundant glycerophospholipid in eukaryotic cells. The existence of four only partially redundant biochemical pathways that produce PE, highlights the importance of this essential phospholipid. The CDP-ethanolamine and phosphatidylserine decarboxylase pathways occur in different subcellular compartments and are the main sources of PE in cells. Mammalian development fails upon ablation of either pathway. Once made, PE has diverse cellular functions that include serving as a precursor for phosphatidylcholine and a substrate for important posttranslational modifications, influencing membrane topology, and promoting cell and organelle membrane fusion, oxidative phosphorylation, mitochondrial biogenesis, and autophagy. The importance of PE metabolism in mammalian health has recently emerged following its association with Alzheimer's disease, Parkinson's disease, nonalcoholic liver disease, and the virulence of certain pathogenic organisms.
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Affiliation(s)
- Elizabeth Calzada
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ouma Onguka
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Steven M Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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31
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Bertholet AM, Delerue T, Millet AM, Moulis MF, David C, Daloyau M, Arnauné-Pelloquin L, Davezac N, Mils V, Miquel MC, Rojo M, Belenguer P. Mitochondrial fusion/fission dynamics in neurodegeneration and neuronal plasticity. Neurobiol Dis 2015; 90:3-19. [PMID: 26494254 DOI: 10.1016/j.nbd.2015.10.011] [Citation(s) in RCA: 253] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 09/16/2015] [Accepted: 10/13/2015] [Indexed: 12/17/2022] Open
Abstract
Mitochondria are dynamic organelles that continually move, fuse and divide. The dynamic balance of fusion and fission of mitochondria determines their morphology and allows their immediate adaptation to energetic needs, keeps mitochondria in good health by restoring or removing damaged organelles or precipitates cells in apoptosis in cases of severe defects. Mitochondrial fusion and fission are essential in mammals and their disturbances are associated with several diseases. However, while mitochondrial fusion/fission dynamics, and the proteins that control these processes, are ubiquitous, associated diseases are primarily neurological disorders. Accordingly, inactivation of the main actors of mitochondrial fusion/fission dynamics is associated with defects in neuronal development, plasticity and functioning, both ex vivo and in vivo. Here, we present the central actors of mitochondrial fusion and fission and review the role of mitochondrial dynamics in neuronal physiology and pathophysiology. Particular emphasis is placed on the three main actors of these processes i.e. DRP1,MFN1-2, and OPA1 as well as on GDAP1, a protein of the mitochondrial outer membrane preferentially expressed in neurons. This article is part of a Special Issue entitled: Mitochondria & Brain.
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Affiliation(s)
- A M Bertholet
- Université de Toulouse, Centre de Biologie du Développement, CNRS, UMR5547/Université Paul Sabatier, Toulouse, France; CNRS, Centre de Biologie du Développement, UMR5547/Université Paul Sabatier, Toulouse, France
| | - T Delerue
- Université de Toulouse, Centre de Biologie du Développement, CNRS, UMR5547/Université Paul Sabatier, Toulouse, France; CNRS, Centre de Biologie du Développement, UMR5547/Université Paul Sabatier, Toulouse, France
| | - A M Millet
- Université de Toulouse, Centre de Biologie du Développement, CNRS, UMR5547/Université Paul Sabatier, Toulouse, France; CNRS, Centre de Biologie du Développement, UMR5547/Université Paul Sabatier, Toulouse, France
| | - M F Moulis
- Université de Toulouse, Centre de Biologie du Développement, CNRS, UMR5547/Université Paul Sabatier, Toulouse, France; CNRS, Centre de Biologie du Développement, UMR5547/Université Paul Sabatier, Toulouse, France
| | - C David
- CNRS, Institut de Biochimie et Génétique Cellulaires (IBGC), UMR5095, Bordeaux, France; Université de Bordeaux, Institut de Biochimie et Génétique Cellulaires (IBGC), UMR5095, Bordeaux, France
| | - M Daloyau
- Université de Toulouse, Centre de Biologie du Développement, CNRS, UMR5547/Université Paul Sabatier, Toulouse, France; CNRS, Centre de Biologie du Développement, UMR5547/Université Paul Sabatier, Toulouse, France
| | - L Arnauné-Pelloquin
- Université de Toulouse, Centre de Biologie du Développement, CNRS, UMR5547/Université Paul Sabatier, Toulouse, France; CNRS, Centre de Biologie du Développement, UMR5547/Université Paul Sabatier, Toulouse, France
| | - N Davezac
- Université de Toulouse, Centre de Biologie du Développement, CNRS, UMR5547/Université Paul Sabatier, Toulouse, France; CNRS, Centre de Biologie du Développement, UMR5547/Université Paul Sabatier, Toulouse, France
| | - V Mils
- Université de Toulouse, Centre de Biologie du Développement, CNRS, UMR5547/Université Paul Sabatier, Toulouse, France; CNRS, Centre de Biologie du Développement, UMR5547/Université Paul Sabatier, Toulouse, France
| | - M C Miquel
- Université de Toulouse, Centre de Biologie du Développement, CNRS, UMR5547/Université Paul Sabatier, Toulouse, France; CNRS, Centre de Biologie du Développement, UMR5547/Université Paul Sabatier, Toulouse, France
| | - M Rojo
- CNRS, Institut de Biochimie et Génétique Cellulaires (IBGC), UMR5095, Bordeaux, France; Université de Bordeaux, Institut de Biochimie et Génétique Cellulaires (IBGC), UMR5095, Bordeaux, France.
| | - P Belenguer
- Université de Toulouse, Centre de Biologie du Développement, CNRS, UMR5547/Université Paul Sabatier, Toulouse, France; CNRS, Centre de Biologie du Développement, UMR5547/Université Paul Sabatier, Toulouse, France.
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32
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Nolli C, Goffrini P, Lazzaretti M, Zanna C, Vitale R, Lodi T, Baruffini E. Validation of a MGM1/OPA1 chimeric gene for functional analysis in yeast of mutations associated with dominant optic atrophy. Mitochondrion 2015; 25:38-48. [PMID: 26455272 DOI: 10.1016/j.mito.2015.10.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 09/24/2015] [Accepted: 10/01/2015] [Indexed: 01/08/2023]
Abstract
Mutations in OPA1 are associated with DOA or DOA plus. Novel mutations in OPA1 are periodically identified, but often the causative effect of the mutation is not demonstrated. A chimeric protein containing the N-terminal region of Mgm1, the yeast orthologue of OPA1, and the C-terminal region of OPA1 was constructed. This chimeric construct can be exploited to evaluate the pathogenicity of most of the missense mutations in OPA1 as well as to determine whether the dominance of the mutation is due to haploinsufficiency or to gain of function.
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Affiliation(s)
- Cecilia Nolli
- Department of Life Sciences, University of Parma, Viale delle Scienze 11/A, 43124 Parma, Italy
| | - Paola Goffrini
- Department of Life Sciences, University of Parma, Viale delle Scienze 11/A, 43124 Parma, Italy
| | - Mirca Lazzaretti
- Department of Life Sciences, University of Parma, Viale delle Scienze 11/A, 43124 Parma, Italy
| | - Claudia Zanna
- Department of Pharmacy and Biotechnology (FABIT), University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, Via Altura 3, 40139 Bologna, Italy
| | - Rita Vitale
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari "Aldo Moro", Piazza Giulio Cesare 11, 70124 Bari, Italy
| | - Tiziana Lodi
- Department of Life Sciences, University of Parma, Viale delle Scienze 11/A, 43124 Parma, Italy
| | - Enrico Baruffini
- Department of Life Sciences, University of Parma, Viale delle Scienze 11/A, 43124 Parma, Italy.
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Yu F, He F, Yao H, Wang C, Wang J, Li J, Qi X, Xue H, Ding J, Zhang P. Structural basis of intramitochondrial phosphatidic acid transport mediated by Ups1-Mdm35 complex. EMBO Rep 2015; 16:813-23. [PMID: 26071601 DOI: 10.15252/embr.201540137] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 05/15/2015] [Indexed: 01/12/2023] Open
Abstract
Ups1 forms a complex with Mdm35 and is critical for the transport of phosphatidic acid (PA) from the mitochondrial outer membrane to the inner membrane. We report the crystal structure of the Ups1-Mdm35-PA complex and the functional characterization of Ups1-Mdm35 in PA binding and transfer. Ups1 features a barrel-like structure consisting of an antiparallel β-sheet and three α-helices. Mdm35 adopts a three-helical clamp-like structure to wrap around Ups1 to form a stable complex. The β-sheet and α-helices of Ups1 form a long tunnel-like pocket to accommodate the substrate PA, and a short helix α2 acts as a lid to cover the pocket. The hydrophobic residues lining the pocket and helix α2 are critical for PA binding and transfer. In addition, a hydrophilic patch on the surface of Ups1 near the PA phosphate-binding site also plays an important role in the function of Ups1-Mdm35. Our study reveals the molecular basis of the function of Ups1-Mdm35 and sheds new light on the mechanism of intramitochondrial phospholipid transport by the MSF1/PRELI family proteins.
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Affiliation(s)
- Fang Yu
- National Center for Protein Science Shanghai and State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences, Shanghai, China
| | - Fangyuan He
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences, Shanghai, China
| | - Hongyan Yao
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences, Shanghai, China
| | - Chengyuan Wang
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences, Shanghai, China
| | - Jianchuan Wang
- National Center for Protein Science Shanghai and State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences, Shanghai, China
| | - Jianxu Li
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences, Shanghai, China
| | - Xiaofeng Qi
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences, Shanghai, China
| | - Hongwei Xue
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences, Shanghai, China
| | - Jianping Ding
- National Center for Protein Science Shanghai and State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences, Shanghai, China
| | - Peng Zhang
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences, Shanghai, China
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Lauritzen KH, Kleppa L, Aronsen JM, Eide L, Carlsen H, Haugen ØP, Sjaastad I, Klungland A, Rasmussen LJ, Attramadal H, Storm-Mathisen J, Bergersen LH. Impaired dynamics and function of mitochondria caused by mtDNA toxicity leads to heart failure. Am J Physiol Heart Circ Physiol 2015; 309:H434-49. [PMID: 26055793 DOI: 10.1152/ajpheart.00253.2014] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 06/02/2015] [Indexed: 11/22/2022]
Abstract
Cardiac mitochondrial dysfunction has been implicated in heart failure of diverse etiologies. Generalized mitochondrial disease also leads to cardiomyopathy with various clinical manifestations. Impaired mitochondrial homeostasis may over time, such as in the aging heart, lead to cardiac dysfunction. Mitochondrial DNA (mtDNA), close to the electron transport chain and unprotected by histones, may be a primary pathogenetic site, but this is not known. Here, we test the hypothesis that cumulative damage of cardiomyocyte mtDNA leads to cardiomyopathy and heart failure. Transgenic mice with Tet-on inducible, cardiomyocyte-specific expression of a mutant uracil-DNA glycosylase 1 (mutUNG1) were generated. The mutUNG1 is known to remove thymine in addition to uracil from the mitochondrial genome, generating apyrimidinic sites, which obstruct mtDNA function. Following induction of mutUNG1 in cardiac myocytes by administering doxycycline, the mice developed hypertrophic cardiomyopathy, leading to congestive heart failure and premature death after ∼2 mo. The heart showed reduced mtDNA replication, severely diminished mtDNA transcription, and suppressed mitochondrial respiration with increased Pgc-1α, mitochondrial mass, and antioxidative defense enzymes, and finally failing mitochondrial fission/fusion dynamics and deteriorating myocardial contractility as the mechanism of heart failure. The approach provides a model with induced cardiac-restricted mtDNA damage for investigation of mtDNA-based heart disease.
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Affiliation(s)
- Knut H Lauritzen
- Department of Oral Biology, Brain and Muscle Energy Group, University of Oslo, Oslo, Norway; Department of Anatomy, Institute of Basic Medical Sciences, and Healthy Brain Ageing Centre, University of Oslo, Oslo, Norway
| | - Liv Kleppa
- Department of Oral Biology, Brain and Muscle Energy Group, University of Oslo, Oslo, Norway; Department of Anatomy, Institute of Basic Medical Sciences, and Healthy Brain Ageing Centre, University of Oslo, Oslo, Norway
| | - Jan Magnus Aronsen
- Institute for Experimental Medical Research, Oslo University Hospital Ullevål and University of Oslo, Oslo, Norway; KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Norway, Oslo, Norway
| | - Lars Eide
- Department of Medical Biochemistry, University of Oslo, Oslo, Norway
| | - Harald Carlsen
- Department of Nutrition Research, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Øyvind P Haugen
- Department of Oral Biology, Brain and Muscle Energy Group, University of Oslo, Oslo, Norway; Department of Anatomy, Institute of Basic Medical Sciences, and Healthy Brain Ageing Centre, University of Oslo, Oslo, Norway
| | - Ivar Sjaastad
- Institute for Experimental Medical Research, Oslo University Hospital Ullevål and University of Oslo, Oslo, Norway; KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Norway, Oslo, Norway
| | - Arne Klungland
- Department of Nutrition Research, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway; Institute of Medical Microbiology, Oslo University Hospital, Oslo, Norway
| | - Lene Juel Rasmussen
- Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark; Department of Cellular and Molecular Medicine, University of Copenhagen, Denmark
| | - Håvard Attramadal
- Institute for Surgical Research, Oslo University Hospital, Oslo, Norway; and Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Jon Storm-Mathisen
- Department of Anatomy, Institute of Basic Medical Sciences, and Healthy Brain Ageing Centre, University of Oslo, Oslo, Norway
| | - Linda H Bergersen
- Department of Oral Biology, Brain and Muscle Energy Group, University of Oslo, Oslo, Norway; Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark;
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Simultaneous impairment of mitochondrial fission and fusion reduces mitophagy and shortens replicative lifespan. Sci Rep 2015; 5:7885. [PMID: 25601284 PMCID: PMC4298727 DOI: 10.1038/srep07885] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 12/18/2014] [Indexed: 12/23/2022] Open
Abstract
Aging of biological systems is accompanied by degeneration of mitochondrial functions. Different pathways are active to counteract the processes which lead to mitochondrial dysfunction. Mitochondrial dynamics, the fission and fusion of mitochondria, is one of these quality control pathways. Mitophagy, the controlled degradation of mitochondria, is another one. Here we show that these pathways are linked. A double deletion mutant of Saccharomyces cerevisiae in which two essential components of the fission and fusion machinery, Dnm1 and Mgm1, are simultaneously ablated, contain wild-type like filamentous mitochondria, but are characterized by impaired respiration, an increased sensitivity to different stressors, increased mitochondrial protein carbonylation, and a decrease in mitophagy and replicative lifespan. These data show that a balanced mitochondrial dynamics and not a filamentous mitochondrial morphotype per se is the key for a long lifespan and demonstrate a cross-talk between two different mitochondrial quality control pathways.
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Fukuoh A, Cannino G, Gerards M, Buckley S, Kazancioglu S, Scialo F, Lihavainen E, Ribeiro A, Dufour E, Jacobs HT. Screen for mitochondrial DNA copy number maintenance genes reveals essential role for ATP synthase. Mol Syst Biol 2014; 10:734. [PMID: 24952591 PMCID: PMC4265055 DOI: 10.15252/msb.20145117] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The machinery of mitochondrial DNA (mtDNA) maintenance is only partially characterized and is of wide interest due to its involvement in disease. To identify novel components of this machinery, plus other cellular pathways required for mtDNA viability, we implemented a genome-wide RNAi screen in Drosophila S2 cells, assaying for loss of fluorescence of mtDNA nucleoids stained with the DNA-intercalating agent PicoGreen. In addition to previously characterized components of the mtDNA replication and transcription machineries, positives included many proteins of the cytosolic proteasome and ribosome (but not the mitoribosome), three proteins involved in vesicle transport, some other factors involved in mitochondrial biogenesis or nuclear gene expression, > 30 mainly uncharacterized proteins and most subunits of ATP synthase (but no other OXPHOS complex). ATP synthase knockdown precipitated a burst of mitochondrial ROS production, followed by copy number depletion involving increased mitochondrial turnover, not dependent on the canonical autophagy machinery. Our findings will inform future studies of the apparatus and regulation of mtDNA maintenance, and the role of mitochondrial bioenergetics and signaling in modulating mtDNA copy number.
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Affiliation(s)
- Atsushi Fukuoh
- BioMediTech and Tampere University Hospital, University of Tampere, Tampere, Finland Department of Clinical Chemistry and Laboratory Medicine, Kyushu University Graduate school of Medical Sciences, Fukuoka, Japan Department of Medical Laboratory Science, Junshin Gakuen University, Fukuoka, Japan
| | - Giuseppe Cannino
- BioMediTech and Tampere University Hospital, University of Tampere, Tampere, Finland
| | - Mike Gerards
- BioMediTech and Tampere University Hospital, University of Tampere, Tampere, Finland
| | - Suzanne Buckley
- BioMediTech and Tampere University Hospital, University of Tampere, Tampere, Finland
| | - Selena Kazancioglu
- BioMediTech and Tampere University Hospital, University of Tampere, Tampere, Finland
| | - Filippo Scialo
- BioMediTech and Tampere University Hospital, University of Tampere, Tampere, Finland
| | - Eero Lihavainen
- Department of Signal Processing, Tampere University of Technology, Tampere, Finland
| | - Andre Ribeiro
- Department of Signal Processing, Tampere University of Technology, Tampere, Finland
| | - Eric Dufour
- BioMediTech and Tampere University Hospital, University of Tampere, Tampere, Finland
| | - Howard T Jacobs
- BioMediTech and Tampere University Hospital, University of Tampere, Tampere, Finland Research Program of Molecular Neurology, University of Helsinki, Helsinki, Finland
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Vidoni S, Zanna C, Rugolo M, Sarzi E, Lenaers G. Why mitochondria must fuse to maintain their genome integrity. Antioxid Redox Signal 2013; 19:379-88. [PMID: 23350575 PMCID: PMC3700062 DOI: 10.1089/ars.2012.4800] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
SIGNIFICANCE The maintenance of mitochondrial genome integrity is a major challenge for cells to sustain energy production by respiration. RECENT ADVANCES Recently, mitochondrial membrane dynamics emerged as a key process contributing to prevent mitochondrial DNA (mtDNA) alterations. Indeed, both fundamental and clinical data suggest that disruption of mitochondrial fusion, related to mutations in the OPA1, MFN2, PINK1, and PARK2 genes, leads to the accumulation of mutations in the mitochondrial genome. CRITICAL ISSUES We discuss here the possibility that mitochondrial fusion acts as a direct mechanism to prevent the generation of altered mtDNA and to eliminate mutated deleterious genomes either by trans-complementation or by mitophagy. FUTURE DIRECTIONS Finally, we conclude this review with a short evolutionary comparison between the mechanisms involved in mitochondrial and bacterial modes of genome distribution and plasticity, highlighting possible common conserved processes required for the maintenance of their genome integrity, which should inspire our future investigations.
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Affiliation(s)
- Sara Vidoni
- INSERM U1051, Institut des Neurosciences de Montpellier, Université de Montpellier I et II, Montpellier, France
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Abstract
SIGNIFICANCE Mitochondria are dynamic organelles capable of changing their shape and distribution by undergoing either fission or fusion. Changes in mitochondrial dynamics, which is under the control of specific mitochondrial fission and fusion proteins, have been implicated in cell division, embryonic development, apoptosis, autophagy, and metabolism. Although the machinery for modulating mitochondrial dynamics is present in the cardiovascular system, its function there has only recently been investigated. In this article, we review the emerging role of mitochondrial dynamics in cardiovascular health and disease. RECENT ADVANCES Changes in mitochondrial dynamics have been implicated in vascular smooth cell proliferation, cardiac development and differentiation, cardiomyocyte hypertrophy, myocardial ischemia-reperfusion injury, cardioprotection, and heart failure. CRITICAL ISSUES Many of the experimental studies investigating mitochondrial dynamics in the cardiovascular system have been confined to cardiac cell lines, vascular cells, or neonatal cardiomyocytes, in which mitochondria are distributed throughout the cytoplasm and are free to move. However, in the adult heart where mitochondrial movements are restricted by their tightly-packed distribution along myofibrils or beneath the subsarcolemma, the relevance of mitochondrial dynamics is less obvious. The investigation of transgenic mice deficient in cardiac mitochondrial fission or fusion proteins should help elucidate the role of mitochondrial dynamics in the adult heart. FUTURE DIRECTIONS Investigating the role of mitochondrial dynamics in cardiovascular health and disease should result in the identification of novel therapeutic targets for treating patients with cardiovascular disease, the leading cause of death and disability globally.
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Affiliation(s)
- Sang-Bing Ong
- Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, San Diego, San Diego, CA, USA
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Abstract
Shape changes and topological remodeling of membranes are essential for the identity of organelles and membrane trafficking. Although all cellular membranes have common features, membranes of different organelles create unique environments that support specialized biological functions. The endoplasmic reticulum (ER) is a prime example of this specialization, as its lipid bilayer forms an interconnected system of cisternae, vesicles, and tubules, providing a highly compartmentalized structure for a multitude of biochemical processes. A variety of peripheral and integral membrane proteins that facilitate membrane curvature generation, fission, and/or fusion have been identified over the past two decades. Among these, the dynamin-related proteins (DRPs) have emerged as key players. Here, we review recent advances in our functional and molecular understanding of fusion DRPs, exemplified by atlastin, an ER-resident DRP that controls ER structure, function, and signaling.
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Affiliation(s)
- James A McNew
- Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77005;
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van der Bliek AM, Shen Q, Kawajiri S. Mechanisms of mitochondrial fission and fusion. Cold Spring Harb Perspect Biol 2013; 5:5/6/a011072. [PMID: 23732471 DOI: 10.1101/cshperspect.a011072] [Citation(s) in RCA: 553] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Mitochondria continually change shape through the combined actions of fission, fusion, and movement along cytoskeletal tracks. The lengths of mitochondria and the degree to which they form closed networks are determined by the balance between fission and fusion rates. These rates are influenced by metabolic and pathogenic conditions inside mitochondria and by their cellular environment. Fission and fusion are important for growth, for mitochondrial redistribution, and for maintenance of a healthy mitochondrial network. In addition, mitochondrial fission and fusion play prominent roles in disease-related processes such as apoptosis and mitophagy. Three members of the Dynamin family are key components of the fission and fusion machineries. Their functions are controlled by different sets of adaptor proteins on the surface of mitochondria and by a range of regulatory processes. Here, we review what is known about these proteins and the processes that regulate their actions.
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Affiliation(s)
- Alexander M van der Bliek
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095, USA.
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Piquereau J, Caffin F, Novotova M, Lemaire C, Veksler V, Garnier A, Ventura-Clapier R, Joubert F. Mitochondrial dynamics in the adult cardiomyocytes: which roles for a highly specialized cell? Front Physiol 2013; 4:102. [PMID: 23675354 PMCID: PMC3650619 DOI: 10.3389/fphys.2013.00102] [Citation(s) in RCA: 161] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 04/23/2013] [Indexed: 11/17/2022] Open
Abstract
Mitochondrial dynamics is a recent topic of research in the field of cardiac physiology. The study of mechanisms involved in the morphological changes and in the mobility of mitochondria is legitimate since the adult cardiomyocytes possess numerous mitochondria which occupy at least 30% of cell volume. However, architectural constraints exist in the cardiomyocyte that limit mitochondrial movements and communication between adjacent mitochondria. Still, the proteins involved in mitochondrial fusion and fission are highly expressed in these cells and could be involved in different processes important for the cardiac function. For example, they are required for mitochondrial biogenesis to synthesize new mitochondria and for the quality-control of the organelles. They are also involved in inner membrane organization and may play a role in apoptosis. More generally, change in mitochondrial morphology can have consequences in the functioning of the respiratory chain, in the regulation of the mitochondrial permeability transition pore (MPTP), and in the interactions with other organelles. Furthermore, the proteins involved in fusion and fission of mitochondria are altered in cardiac pathologies such as ischemia/reperfusion or heart failure (HF), and appear to be valuable targets for pharmacological therapies. Thus, mitochondrial dynamics deserves particular attention in cardiac research. The present review draws up a report of our knowledge on these phenomena.
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Affiliation(s)
- Jerome Piquereau
- Department of Signaling and Cardiac Pathophysiology, U-769, INSERM Châtenay-Malabry, France ; IFR141, Université Paris-Sud Châtenay-Malabry, France
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Su YC, Qi X. Impairment of mitochondrial dynamics: a target for the treatment of neurological disorders? FUTURE NEUROLOGY 2013. [DOI: 10.2217/fnl.13.8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mitochondrial dysfunction has long been appreciated in the pathogenesis of various neurological disorders. However, the molecular basis underlying the decline in mitochondrial function is not fully understood. Mitochondria are highly dynamic organelles that frequently undergo fusion and fission. In healthy cells, the delicate balance between fusion and fission is required for maintaining normal mitochondrial and cellular function. However, under pathological conditions, the balance is disrupted, resulting in excessive mitochondrial fragmentation and mitochondrial dysfunction. The impaired fusion and fission processes can lead to apoptosis, necrosis and autophagic cell death and seem to play causal roles in the progression of acute and chronic neuronal injuries. In this article, important aspects of what is currently known about the molecular machinery regulating mitochondrial fission and fusion in mammalian cells is summarized. Special emphasis will be given to the consequences of disregulated mitochondrial morphology in the pathogenesis of neurological diseases.
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Affiliation(s)
- Yu-Chin Su
- Department of Physiology & Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Xin Qi
- Center for Mitochondrial Diseases, Case Western Reserve University School of Medicine, 10900 Euclid Avenue, E516, Cleveland, OH, 44106-44970, USA
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Pierce S, Gersak K, Michaelson-Cohen R, Walsh T, Lee M, Malach D, Klevit R, King MC, Levy-Lahad E. Mutations in LARS2, encoding mitochondrial leucyl-tRNA synthetase, lead to premature ovarian failure and hearing loss in Perrault syndrome. Am J Hum Genet 2013; 92:614-20. [PMID: 23541342 DOI: 10.1016/j.ajhg.2013.03.007] [Citation(s) in RCA: 150] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2012] [Revised: 02/25/2013] [Accepted: 03/11/2013] [Indexed: 11/25/2022] Open
Abstract
The genetic causes of premature ovarian failure (POF) are highly heterogeneous, and causative mutations have been identified in more than ten genes so far. In two families affected by POF accompanied by hearing loss (together, these symptoms compose Perrault syndrome), exome sequencing revealed mutations in LARS2, encoding mitochondrial leucyl-tRNA synthetase: homozygous c.1565C>A (p.Thr522Asn) in a consanguineous Palestinian family and compound heterozygous c.1077delT and c.1886C>T (p.Thr629Met) in a nonconsanguineous Slovenian family. LARS2 c.1077delT leads to a frameshift at codon 360 of the 901 residue protein. LARS2 p.Thr522Asn occurs in the LARS2 catalytic domain at a site conserved from bacteria through mammals. LARS2 p.Thr629Met occurs in the LARS2 leucine-specific domain, which is adjacent to a catalytic loop critical in all species but for which primary sequence is not well conserved. A recently developed method of detecting remote homologies revealed threonine at this site in consensus sequences derived from multiple-species alignments seeded by human and E. coli residues at this region. Yeast complementation indicated that LARS2 c.1077delT is nonfunctional and that LARS2 p.Thr522Asn is partially functional. LARS2 p.Thr629Met was functional in this assay but might be insufficient as a heterozygote with the fully nonfunctional LARS2 c.1077delT allele. A known C. elegans strain with the protein-truncating alteration LARS-2 p.Trp247Ter was confirmed to be sterile. After HARS2, LARS2 is the second gene encoding mitochondrial tRNA synthetase to be found to harbor mutations leading to Perrault syndrome, further supporting a critical role for mitochondria in the maintenance of ovarian function and hearing.
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Belenguer P, Pellegrini L. The dynamin GTPase OPA1: More than mitochondria? BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:176-83. [DOI: 10.1016/j.bbamcr.2012.08.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 08/01/2012] [Accepted: 08/03/2012] [Indexed: 12/24/2022]
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A uvs-5 strain is deficient for a mitofusin gene homologue, fzo1, involved in maintenance of long life span in Neurospora crassa. EUKARYOTIC CELL 2012; 12:233-43. [PMID: 23223037 DOI: 10.1128/ec.00226-12] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Mitochondria are highly dynamic organelles that continuously fuse and divide. To maintain mitochondria, cells establish an equilibrium of fusion and fission events, which are mediated by dynamin-like GTPases. We previously showed that an mus-10 strain, a mutagen-sensitive strain of the filamentous fungus Neurospora crassa, is defective in an F-box protein that is essential for the maintenance of mitochondrial DNA (mtDNA), long life span, and mitochondrial morphology. Similarly, a uvs-5 mutant accumulates deletions within its mtDNA, has a shortened life span, and harbors fragmented mitochondria, the latter of which is indicative of an imbalance between mitochondrial fission and fusion. Since the uvs-5 mutation maps very close to the locus of fzo1, encoding a mitofusin homologue thought to mediate mitochondrial outer membrane fusion, we determined the sequence of the fzo1 gene in the uvs-5 mutant. A single amino acid substitution (Q368R) was found in the GTPase domain of the FZO1 protein. Expression of wild-type FZO1 in the uvs-5 strain rescued the mutant phenotypes, while expression of a mutant FZO1 protein did not. Moreover, when knock-in of the Q368R mutation was performed on a wild-type strain, the resulting mutant displayed phenotypes identical to those of the uvs-5 mutant. Therefore, we concluded that the previously unidentified uvs-5 gene is fzo1. Furthermore, we used immunoprecipitation analysis to show that the FZO1 protein interacts with MUS-10, which suggests that these two proteins may function together to maintain mitochondrial morphology.
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46
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Bioenergetic role of mitochondrial fusion and fission. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1817:1833-8. [DOI: 10.1016/j.bbabio.2012.02.033] [Citation(s) in RCA: 432] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 02/24/2012] [Accepted: 02/25/2012] [Indexed: 11/22/2022]
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Escobar-Henriques M, Anton F. Mechanistic perspective of mitochondrial fusion: tubulation vs. fragmentation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:162-75. [PMID: 22884630 DOI: 10.1016/j.bbamcr.2012.07.016] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 07/28/2012] [Accepted: 07/30/2012] [Indexed: 01/02/2023]
Abstract
Mitochondrial fusion is a fundamental process driven by dynamin related GTPase proteins (DRPs), in contrast to the general SNARE-dependence of most cellular fusion events. The DRPs Mfn1/Mfn2/Fzo1 and OPA1/Mgm1 are the key effectors for fusion of the mitochondrial outer and inner membranes, respectively. In order to promote fusion, these two DRPs require post-translational modifications and proteolysis. OPA1/Mgm1 undergoes partial proteolytic processing, which results in a combination between short and long isoforms. In turn, ubiquitylation of mitofusins, after oligomerization and GTP hydrolysis, promotes and positively regulates mitochondrial fusion. In contrast, under conditions of mitochondrial dysfunction, negative regulation by proteolysis on these DRPs results in mitochondrial fragmentation. This occurs by complete processing of OPA1 and via ubiquitylation and degradation of mitofusins. Mitochondrial fragmentation contributes to the elimination of damaged mitochondria by mitophagy, and may play a protective role against Parkinson's disease. Moreover, a link of Mfn2 to Alzheimer's disease is emerging and mutations in Mfn2 or OPA1 cause Charcot-Marie-Tooth type 2A neuropathy or autosomal-dominant optic atrophy. Here, we summarize our current understanding on the molecular mechanisms promoting or inhibiting fusion of mitochondrial membranes, which is essential for cellular survival and disease control. This article is part of a Special Issue entitled: Mitochondrial dynamics and physiology.
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48
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Zhao J, Lendahl U, Nistér M. Regulation of mitochondrial dynamics: convergences and divergences between yeast and vertebrates. Cell Mol Life Sci 2012; 70:951-76. [PMID: 22806564 PMCID: PMC3578726 DOI: 10.1007/s00018-012-1066-6] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 06/18/2012] [Accepted: 06/19/2012] [Indexed: 12/20/2022]
Abstract
In eukaryotic cells, the shape of mitochondria can be tuned to various physiological conditions by a balance of fusion and fission processes termed mitochondrial dynamics. Mitochondrial dynamics controls not only the morphology but also the function of mitochondria, and therefore is crucial in many aspects of a cell’s life. Consequently, dysfunction of mitochondrial dynamics has been implicated in a variety of human diseases including cancer. Several proteins important for mitochondrial fusion and fission have been discovered over the past decade. However, there is emerging evidence that there are as yet unidentified proteins important for these processes and that the fusion/fission machinery is not completely conserved between yeast and vertebrates. The recent characterization of several mammalian proteins important for the process that were not conserved in yeast, may indicate that the molecular mechanisms regulating and controlling the morphology and function of mitochondria are more elaborate and complex in vertebrates. This difference could possibly be a consequence of different needs in the different cell types of multicellular organisms. Here, we review recent advances in the field of mitochondrial dynamics. We highlight and discuss the mechanisms regulating recruitment of cytosolic Drp1 to the mitochondrial outer membrane by Fis1, Mff, and MIEF1 in mammals and the divergences in regulation of mitochondrial dynamics between yeast and vertebrates.
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Affiliation(s)
- Jian Zhao
- Department of Oncology-Pathology, Karolinska Institutet, CCK R8:05, Karolinska University Hospital Solna, 171 76, Stockholm, Sweden,
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Cell signaling and mitochondrial dynamics: Implications for neuronal function and neurodegenerative disease. Neurobiol Dis 2012; 51:13-26. [PMID: 22297163 DOI: 10.1016/j.nbd.2012.01.009] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Revised: 01/09/2012] [Accepted: 01/12/2012] [Indexed: 11/22/2022] Open
Abstract
Nascent evidence indicates that mitochondrial fission, fusion, and transport are subject to intricate regulatory mechanisms that intersect with both well-characterized and emerging signaling pathways. While it is well established that mutations in components of the mitochondrial fission/fusion machinery can cause neurological disorders, relatively little is known about upstream regulators of mitochondrial dynamics and their role in neurodegeneration. Here, we review posttranslational regulation of mitochondrial fission/fusion enzymes, with particular emphasis on dynamin-related protein 1 (Drp1), as well as outer mitochondrial signaling complexes involving protein kinases and phosphatases. We also review recent evidence that mitochondrial dynamics has profound consequences for neuronal development and synaptic transmission and discuss implications for clinical translation.
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50
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Hori A, Yoshida M, Ling F. Mitochondrial fusion increases the mitochondrial DNA copy number in budding yeast. Genes Cells 2011; 16:527-44. [PMID: 21463454 DOI: 10.1111/j.1365-2443.2011.01504.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Mitochondrial fusion plays an important role in mitochondrial DNA (mtDNA) maintenance, although the underlying mechanisms are unclear. In budding yeast, certain levels of reactive oxygen species (ROS) can promote recombination-mediated mtDNA replication, and mtDNA maintenance depends on the homologous DNA pairing protein Mhr1. Here, we show that the fusion of isolated yeast mitochondria, which can be monitored by the bimolecular fluorescence complementation-derived green fluorescent protein (GFP) fluorescence, increases the mtDNA copy number in a manner dependent on Mhr1. The fusion event, accompanied by the degradation of dissociated electron transport chain complex IV and transient reductions in the complex IV subunits by the inner membrane AAA proteases such as Yme1, increases ROS levels. Analysis of the initial stage of mitochondrial fusion in early log-phase cells produced similar results. Moreover, higher ROS levels in mitochondrial fusion-deficient mutant cells increased the amount of newly synthesized mtDNA, resulting in increases in the mtDNA copy number. In contrast, reducing ROS levels in yme1 null mutant cells significantly decreased the mtDNA copy number, leading to an increase in cells lacking mtDNA. Our results indicate that mitochondrial fusion induces mtDNA synthesis by facilitating ROS-triggered, recombination-mediated replication and thereby prevents the generation of mitochondria lacking DNA.
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Affiliation(s)
- Akiko Hori
- Chemical Genetics Laboratory, RIKEN Advanced Science Institute, Hirosawa, Wako-shi, Saitama, Japan
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