1
|
Burr SP, Klimm F, Glynos A, Prater M, Sendon P, Nash P, Powell CA, Simard ML, Bonekamp NA, Charl J, Diaz H, Bozhilova LV, Nie Y, Zhang H, Frison M, Falkenberg M, Jones N, Minczuk M, Stewart JB, Chinnery PF. Cell lineage-specific mitochondrial resilience during mammalian organogenesis. Cell 2023; 186:1212-1229.e21. [PMID: 36827974 DOI: 10.1016/j.cell.2023.01.034] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 10/28/2022] [Accepted: 01/26/2023] [Indexed: 02/25/2023]
Abstract
Mitochondrial activity differs markedly between organs, but it is not known how and when this arises. Here we show that cell lineage-specific expression profiles involving essential mitochondrial genes emerge at an early stage in mouse development, including tissue-specific isoforms present before organ formation. However, the nuclear transcriptional signatures were not independent of organelle function. Genetically disrupting intra-mitochondrial protein synthesis with two different mtDNA mutations induced cell lineage-specific compensatory responses, including molecular pathways not previously implicated in organellar maintenance. We saw downregulation of genes whose expression is known to exacerbate the effects of exogenous mitochondrial toxins, indicating a transcriptional adaptation to mitochondrial dysfunction during embryonic development. The compensatory pathways were both tissue and mutation specific and under the control of transcription factors which promote organelle resilience. These are likely to contribute to the tissue specificity which characterizes human mitochondrial diseases and are potential targets for organ-directed treatments.
Collapse
Affiliation(s)
- Stephen P Burr
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK; Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - Florian Klimm
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK; Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK; Department of Mathematics, Imperial College London, London, UK; EPSRC Centre for Mathematics of Precision Healthcare, Imperial College, London, UK; Department of Computational Molecular Biology, Max Planck Institute for Molecular Genetics, Ihnestraße 63-73, D-14195 Berlin, Germany; Department of Computer Science, Freie Universität Berlin, Arnimallee 3, D-14195 Berlin, Germany
| | - Angelos Glynos
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK; Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - Malwina Prater
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK; Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - Pamella Sendon
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Pavel Nash
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - Christopher A Powell
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | | | - Nina A Bonekamp
- Max Planck Institute for Biology of Ageing, Cologne, Germany; Department of Neuroanatomy, Mannheim Centre for Translational Neuroscience (MCTN), Medical Faculty Mannheim/Heidelberg University, Heidelberg, Germany
| | - Julia Charl
- Institute of Biochemistry, University of Cologne, Otto-Fischer-Strasse 12-14, Cologne, Germany
| | - Hector Diaz
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, PO Box 440, Gothenburg 405 30, Sweden
| | - Lyuba V Bozhilova
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK; Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - Yu Nie
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK; Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - Haixin Zhang
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK; Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - Michele Frison
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK; Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - Maria Falkenberg
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, PO Box 440, Gothenburg 405 30, Sweden
| | - Nick Jones
- Department of Mathematics, Imperial College London, London, UK
| | - Michal Minczuk
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - James B Stewart
- Max Planck Institute for Biology of Ageing, Cologne, Germany; Biosciences Institute, Faculty of Medical Sciences, Wellcome Centre for Mitochondrial Research, Newcastle University, Newcastle upon Tyne, UK
| | - Patrick F Chinnery
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK; Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK.
| |
Collapse
|
2
|
Schrader TA, Carmichael RE, Islinger M, Costello JL, Hacker C, Bonekamp NA, Weishaupt JH, Andersen PM, Schrader M. PEX11β and FIS1 cooperate in peroxisome division independently of mitochondrial fission factor. J Cell Sci 2022; 135:275634. [PMID: 35678336 PMCID: PMC9377713 DOI: 10.1242/jcs.259924] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 05/27/2022] [Indexed: 11/20/2022] Open
Abstract
Peroxisome membrane dynamics and division are essential to adapt the peroxisomal compartment to cellular needs. The peroxisomal membrane protein PEX11β (also known as PEX11B) and the tail-anchored adaptor proteins FIS1 (mitochondrial fission protein 1) and MFF (mitochondrial fission factor), which recruit the fission GTPase DRP1 (dynamin-related protein 1, also known as DNML1) to both peroxisomes and mitochondria, are key factors of peroxisomal division. The current model suggests that MFF is essential for peroxisome division, whereas the role of FIS1 is unclear. Here, we reveal that PEX11β can promote peroxisome division in the absence of MFF in a DRP1- and FIS1-dependent manner. We also demonstrate that MFF permits peroxisome division independently of PEX11β and restores peroxisome morphology in PEX11β-deficient patient cells. Moreover, targeting of PEX11β to mitochondria induces mitochondrial division, indicating the potential for PEX11β to modulate mitochondrial dynamics. Our findings suggest the existence of an alternative, MFF-independent pathway in peroxisome division and report a function for FIS1 in the division of peroxisomes. This article has an associated First Person interview with the first authors of the paper.
Collapse
Affiliation(s)
- Tina A. Schrader
- College of Life and Environmental Sciences, Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - Ruth E. Carmichael
- College of Life and Environmental Sciences, Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - Markus Islinger
- Institute of Neuroanatomy, Mannheim Centre for Translational Neuroscience, Medical Faculty Mannheim, University of Heidelberg, 68167 Mannheim, Germany
| | - Joseph L. Costello
- College of Life and Environmental Sciences, Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - Christian Hacker
- College of Life and Environmental Sciences, Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - Nina A. Bonekamp
- Institute of Neuroanatomy, Mannheim Centre for Translational Neuroscience, Medical Faculty Mannheim, University of Heidelberg, 68167 Mannheim, Germany
| | - Jochen H. Weishaupt
- Division of Neurodegeneration, Department of Neurology, Mannheim Center for Translational Neurosciences, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
| | - Peter M. Andersen
- Department of Clinical Science, Neurosciences, Umeå University, Umeå SE-90185, Sweden
| | - Michael Schrader
- College of Life and Environmental Sciences, Biosciences, University of Exeter, Exeter EX4 4QD, UK
- Author for correspondence ()
| |
Collapse
|
3
|
Miranda M, Bonekamp NA, Kühl I. Starting the engine of the powerhouse: mitochondrial transcription and beyond. Biol Chem 2022; 403:779-805. [PMID: 35355496 DOI: 10.1515/hsz-2021-0416] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 03/09/2022] [Indexed: 12/25/2022]
Abstract
Mitochondria are central hubs for cellular metabolism, coordinating a variety of metabolic reactions crucial for human health. Mitochondria provide most of the cellular energy via their oxidative phosphorylation (OXPHOS) system, which requires the coordinated expression of genes encoded by both the nuclear (nDNA) and mitochondrial genomes (mtDNA). Transcription of mtDNA is not only essential for the biogenesis of the OXPHOS system, but also generates RNA primers necessary to initiate mtDNA replication. Like the prokaryotic system, mitochondria have no membrane-based compartmentalization to separate the different steps of mtDNA maintenance and expression and depend entirely on nDNA-encoded factors imported into the organelle. Our understanding of mitochondrial transcription in mammalian cells has largely progressed, but the mechanisms regulating mtDNA gene expression are still poorly understood despite their profound importance for human disease. Here, we review mechanisms of mitochondrial gene expression with a focus on the recent findings in the field of mammalian mtDNA transcription and disease phenotypes caused by defects in proteins involved in this process.
Collapse
Affiliation(s)
- Maria Miranda
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, D-50931, Germany
| | - Nina A Bonekamp
- Department of Neuroanatomy, Mannheim Center for Translational Neurosciences (MCTN), Medical Faculty Mannheim, Heidelberg University, Mannheim, D-68167, Germany
| | - Inge Kühl
- Department of Cell Biology, Institute of Integrative Biology of the Cell (I2BC), UMR9198, CEA, CNRS, Université Paris-Saclay, Gif-sur-Yvette, F-91190, France
| |
Collapse
|
4
|
Mennuni M, Filograna R, Felser A, Bonekamp NA, Giavalisco P, Lytovchenko O, Larsson N. Metabolic resistance to the inhibition of mitochondrial transcription revealed by CRISPR-Cas9 screen. EMBO Rep 2022; 23:e53054. [PMID: 34779571 PMCID: PMC8728608 DOI: 10.15252/embr.202153054] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 10/12/2021] [Accepted: 10/19/2021] [Indexed: 12/20/2022] Open
Abstract
Cancer cells depend on mitochondria to sustain their increased metabolic need and mitochondria therefore constitute possible targets for cancer treatment. We recently developed small-molecule inhibitors of mitochondrial transcription (IMTs) that selectively impair mitochondrial gene expression. IMTs have potent antitumor properties in vitro and in vivo, without affecting normal tissues. Because therapy-induced resistance is a major constraint to successful cancer therapy, we investigated mechanisms conferring resistance to IMTs. We employed a CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats)-(CRISP-associated protein 9) whole-genome screen to determine pathways conferring resistance to acute IMT1 treatment. Loss of genes belonging to von Hippel-Lindau (VHL) and mammalian target of rapamycin complex 1 (mTORC1) pathways caused resistance to acute IMT1 treatment and the relevance of these pathways was confirmed by chemical modulation. We also generated cells resistant to chronic IMT treatment to understand responses to persistent mitochondrial gene expression impairment. We report that IMT1-acquired resistance occurs through a compensatory increase of mitochondrial DNA (mtDNA) expression and cellular metabolites. We found that mitochondrial transcription factor A (TFAM) downregulation and inhibition of mitochondrial translation impaired survival of resistant cells. The identified susceptibility and resistance mechanisms to IMTs may be relevant for different types of mitochondria-targeted therapies.
Collapse
Affiliation(s)
- Mara Mennuni
- Department of Medical Biochemistry and BiophysicsKarolinska InstitutetStockholmSweden
| | - Roberta Filograna
- Department of Medical Biochemistry and BiophysicsKarolinska InstitutetStockholmSweden
| | - Andrea Felser
- Department of Medical Biochemistry and BiophysicsKarolinska InstitutetStockholmSweden
- University Institute of Clinical ChemistryBern University HospitalBernSwitzerland
| | - Nina A Bonekamp
- Mitochondrial Biology GroupMax Planck Institute for Biology of AgeingCologneGermany
- Department of NeuroanatomyMannheim Center for Translational Neuroscience (MCTN)Medical Faculty MannheimHeidelberg UniversityMannheimGermany
| | - Patrick Giavalisco
- Metabolomics Core FacilityMax Planck Institute for Biology of AgeingCologneGermany
| | - Oleksandr Lytovchenko
- Department of Medical Biochemistry and BiophysicsKarolinska InstitutetStockholmSweden
| | - Nils‐Göran Larsson
- Department of Medical Biochemistry and BiophysicsKarolinska InstitutetStockholmSweden
| |
Collapse
|
5
|
Bonekamp NA, Jiang M, Motori E, Garcia Villegas R, Koolmeister C, Atanassov I, Mesaros A, Park CB, Larsson NG. High levels of TFAM repress mammalian mitochondrial DNA transcription in vivo. Life Sci Alliance 2021; 4:4/11/e202101034. [PMID: 34462320 PMCID: PMC8408345 DOI: 10.26508/lsa.202101034] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 08/10/2021] [Accepted: 08/20/2021] [Indexed: 01/04/2023] Open
Abstract
Mitochondrial transcription factor A (TFAM) is compacting mitochondrial DNA (dmtDNA) into nucleoids and directly controls mtDNA copy number. Here, we show that the TFAM-to-mtDNA ratio is critical for maintaining normal mtDNA expression in different mouse tissues. Moderately increased TFAM protein levels increase mtDNA copy number but a normal TFAM-to-mtDNA ratio is maintained resulting in unaltered mtDNA expression and normal whole animal metabolism. Mice ubiquitously expressing very high TFAM levels develop pathology leading to deficient oxidative phosphorylation (OXPHOS) and early postnatal lethality. The TFAM-to-mtDNA ratio varies widely between tissues in these mice and is very high in skeletal muscle leading to strong repression of mtDNA expression and OXPHOS deficiency. In the heart, increased mtDNA copy number results in a near normal TFAM-to-mtDNA ratio and maintained OXPHOS capacity. In liver, induction of LONP1 protease and mitochondrial RNA polymerase expression counteracts the silencing effect of high TFAM levels. TFAM thus acts as a general repressor of mtDNA expression and this effect can be counterbalanced by tissue-specific expression of regulatory factors.
Collapse
Affiliation(s)
- Nina A Bonekamp
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Min Jiang
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany.,Zhejiang Provincial Laboratory of Life Sciences and Biomedicine, Key Laboratory of Growth Regulation and Transformation Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, China
| | - Elisa Motori
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | | | - Camilla Koolmeister
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Ilian Atanassov
- Proteomics Core Facility, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Andrea Mesaros
- Phenotyping Core Facility, Max Planck Institute for Biology of Ageing, Cologne, 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
| |
Collapse
|
6
|
Bonekamp NA, Peter B, Hillen HS, Felser A, Bergbrede T, Choidas A, Horn M, Unger A, Di Lucrezia R, Atanassov I, Li X, Koch U, Menninger S, Boros J, Habenberger P, Giavalisco P, Cramer P, Denzel MS, Nussbaumer P, Klebl B, Falkenberg M, Gustafsson CM, Larsson NG. Small-molecule inhibitors of human mitochondrial DNA transcription. Nature 2020. [PMID: 33328633 DOI: 10.1038/s41586-020-03048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
Abstract
Altered expression of mitochondrial DNA (mtDNA) occurs in ageing and a range of human pathologies (for example, inborn errors of metabolism, neurodegeneration and cancer). Here we describe first-in-class specific inhibitors of mitochondrial transcription (IMTs) that target the human mitochondrial RNA polymerase (POLRMT), which is essential for biogenesis of the oxidative phosphorylation (OXPHOS) system1-6. The IMTs efficiently impair mtDNA transcription in a reconstituted recombinant system and cause a dose-dependent inhibition of mtDNA expression and OXPHOS in cell lines. To verify the cellular target, we performed exome sequencing of mutagenized cells and identified a cluster of amino acid substitutions in POLRMT that cause resistance to IMTs. We obtained a cryo-electron microscopy (cryo-EM) structure of POLRMT bound to an IMT, which further defined the allosteric binding site near the active centre cleft of POLRMT. The growth of cancer cells and the persistence of therapy-resistant cancer stem cells has previously been reported to depend on OXPHOS7-17, and we therefore investigated whether IMTs have anti-tumour effects. Four weeks of oral treatment with an IMT is well-tolerated in mice and does not cause OXPHOS dysfunction or toxicity in normal tissues, despite inducing a strong anti-tumour response in xenografts of human cancer cells. In summary, IMTs provide a potent and specific chemical biology tool to study the role of mtDNA expression in physiology and disease.
Collapse
Affiliation(s)
- Nina A Bonekamp
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Bradley Peter
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg, Sweden
| | - Hauke S Hillen
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Andrea Felser
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | | | | | - Moritz Horn
- Metabolic and Genetic Regulation of Ageing, Max Planck Institute for Biology of Ageing, Cologne, Germany
- Acus Laboratories, Cologne, Germany
- JLP Health, Vienna, Austria
| | - Anke Unger
- Lead Discovery Center, Dortmund, Germany
| | | | - Ilian Atanassov
- Proteomics Core Facility, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Xinping Li
- Proteomics Core Facility, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Uwe Koch
- Lead Discovery Center, Dortmund, Germany
| | | | | | | | - Patrick Giavalisco
- Metabolomics Core Facility, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Patrick Cramer
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Martin S Denzel
- Metabolic and Genetic Regulation of Ageing, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | | | - Bert Klebl
- Lead Discovery Center, Dortmund, Germany
| | - Maria Falkenberg
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg, Sweden
| | - Claes M Gustafsson
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg, Sweden.
| | - 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.
- Max Planck Institute for Biology of Ageing-Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden.
| |
Collapse
|
7
|
Kauppila JHK, Bonekamp NA, Mourier A, Isokallio MA, Just A, Kauppila TES, Stewart JB, Larsson NG. Base-excision repair deficiency alone or combined with increased oxidative stress does not increase mtDNA point mutations in mice. Nucleic Acids Res 2019; 46:6642-6669. [PMID: 29860357 PMCID: PMC6061787 DOI: 10.1093/nar/gky456] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 05/11/2018] [Indexed: 12/19/2022] Open
Abstract
Mitochondrial DNA (mtDNA) mutations become more prevalent with age and are postulated to contribute to the ageing process. Point mutations of mtDNA have been suggested to originate from two main sources, i.e. replicative errors and oxidative damage, but the contribution of each of these processes is much discussed. To elucidate the origin of mtDNA mutations, we measured point mutation load in mice with deficient mitochondrial base-excision repair (BER) caused by knockout alleles preventing mitochondrial import of the DNA repair glycosylases OGG1 and MUTYH (Ogg1 dMTS, Mutyh dMTS). Surprisingly, we detected no increase in the mtDNA mutation load in old Ogg1 dMTS mice. As DNA repair is especially important in the germ line, we bred the BER deficient mice for five consecutive generations but found no increase in the mtDNA mutation load in these maternal lineages. To increase reactive oxygen species (ROS) levels and oxidative damage, we bred the Ogg1 dMTS mice with tissue specific Sod2 knockout mice. Although increased superoxide levels caused a plethora of changes in mitochondrial function, we did not detect any changes in the mutation load of mtDNA or mtRNA. Our results show that the importance of oxidative damage as a contributor of mtDNA mutations should be re-evaluated.
Collapse
Affiliation(s)
- Johanna H K Kauppila
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Nina A Bonekamp
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Arnaud Mourier
- Université de Bordeaux and the Centre National de la Recherche Scientifique, Institut de Biochimie et Génétique Cellulaires UMR 5095, Saint-Saëns, Bordeaux, France
| | - Marita A Isokallio
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Alexandra Just
- FACS & Imaging Core Facility, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Timo E S Kauppila
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - James B Stewart
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, Cologne, 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
| |
Collapse
|
8
|
Abstract
Mitochondrial DNA is compacted into nucleoprotein complexes denoted mitochondrial nucleoids, the focus of this SnapShot.
Collapse
Affiliation(s)
- Nina A Bonekamp
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, D-50931 Cologne, Germany
| | - Nils-Göran Larsson
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, D-50931 Cologne, Germany; Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 77 Stockholm, Sweden.
| |
Collapse
|
9
|
Costello JL, Castro IG, Camões F, Schrader TA, McNeall D, Yang J, Giannopoulou EA, Gomes S, Pogenberg V, Bonekamp NA, Ribeiro D, Wilmanns M, Jedd G, Islinger M, Schrader M. Predicting the targeting of tail-anchored proteins to subcellular compartments in mammalian cells. J Cell Sci 2017; 130:1675-1687. [PMID: 28325759 PMCID: PMC5450235 DOI: 10.1242/jcs.200204] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 03/14/2017] [Indexed: 12/22/2022] Open
Abstract
Tail-anchored (TA) proteins contain a single transmembrane domain (TMD) at the C-terminus that anchors them to the membranes of organelles where they mediate critical cellular processes. Accordingly, mutations in genes encoding TA proteins have been identified in a number of severe inherited disorders. Despite the importance of correctly targeting a TA protein to its appropriate membrane, the mechanisms and signals involved are not fully understood. In this study, we identify additional peroxisomal TA proteins, discover more proteins that are present on multiple organelles, and reveal that a combination of TMD hydrophobicity and tail charge determines targeting to distinct organelle locations in mammals. Specifically, an increase in tail charge can override a hydrophobic TMD signal and re-direct a protein from the ER to peroxisomes or mitochondria and vice versa. We show that subtle changes in those parameters can shift TA proteins between organelles, explaining why peroxisomes and mitochondria have many of the same TA proteins. This enabled us to associate characteristic physicochemical parameters in TA proteins with particular organelle groups. Using this classification allowed successful prediction of the location of uncharacterized TA proteins for the first time.
Collapse
Affiliation(s)
| | - Inês G Castro
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - Fátima Camões
- Centre for Cell Biology/Institute of Biomedicine & Department of Biology, University of Aveiro, Aveiro 3810-193, Portugal
| | | | | | - Jing Yang
- Temasek Life Sciences Laboratory, Department of Biological Sciences, National University of Singapore, Singapore
| | | | - Sílvia Gomes
- Centre for Cell Biology/Institute of Biomedicine & Department of Biology, University of Aveiro, Aveiro 3810-193, Portugal
| | | | - Nina A Bonekamp
- Centre for Cell Biology/Institute of Biomedicine & Department of Biology, University of Aveiro, Aveiro 3810-193, Portugal
| | - Daniela Ribeiro
- Centre for Cell Biology/Institute of Biomedicine & Department of Biology, University of Aveiro, Aveiro 3810-193, Portugal
| | | | - Gregory Jedd
- Temasek Life Sciences Laboratory, Department of Biological Sciences, National University of Singapore, Singapore
| | - Markus Islinger
- Institute of Neuroanatomy, Center for Biomedicine and Medical Technology Mannheim, University of Heidelberg, Mannheim 68167, Germany
| | - Michael Schrader
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
- Centre for Cell Biology/Institute of Biomedicine & Department of Biology, University of Aveiro, Aveiro 3810-193, Portugal
| |
Collapse
|
10
|
Kühl I, Miranda M, Posse V, Milenkovic D, Mourier A, Siira SJ, Bonekamp NA, Neumann U, Filipovska A, Polosa PL, Gustafsson CM, Larsson NG. POLRMT regulates the switch between replication primer formation and gene expression of mammalian mtDNA. Sci Adv 2016; 2:e1600963. [PMID: 27532055 PMCID: PMC4975551 DOI: 10.1126/sciadv.1600963] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 07/01/2016] [Indexed: 05/27/2023]
Abstract
Mitochondria are vital in providing cellular energy via their oxidative phosphorylation system, which requires the coordinated expression of genes encoded by both the nuclear and mitochondrial genomes (mtDNA). Transcription of the circular mammalian mtDNA depends on a single mitochondrial RNA polymerase (POLRMT). Although the transcription initiation process is well understood, it is debated whether POLRMT also serves as the primase for the initiation of mtDNA replication. In the nucleus, the RNA polymerases needed for gene expression have no such role. Conditional knockout of Polrmt in the heart results in severe mitochondrial dysfunction causing dilated cardiomyopathy in young mice. We further studied the molecular consequences of different expression levels of POLRMT and found that POLRMT is essential for primer synthesis to initiate mtDNA replication in vivo. Furthermore, transcription initiation for primer formation has priority over gene expression. Surprisingly, mitochondrial transcription factor A (TFAM) exists in an mtDNA-free pool in the Polrmt knockout mice. TFAM levels remain unchanged despite strong mtDNA depletion, and TFAM is thus protected from degradation of the AAA(+) Lon protease in the absence of POLRMT. Last, we report that mitochondrial transcription elongation factor may compensate for a partial depletion of POLRMT in heterozygous Polrmt knockout mice, indicating a direct regulatory role of this factor in transcription. In conclusion, we present in vivo evidence that POLRMT has a key regulatory role in the replication of mammalian mtDNA and is part of a transcriptional mechanism that provides a switch between primer formation for mtDNA replication and mitochondrial gene expression.
Collapse
Affiliation(s)
- Inge Kühl
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, 50931 Cologne, Germany
| | - Maria Miranda
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, 50931 Cologne, Germany
| | - Viktor Posse
- Department of Medical Biochemistry and Cell Biology, Göteborgs Universitet, 40530 Göteborg, Sweden
| | - Dusanka Milenkovic
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, 50931 Cologne, Germany
| | - Arnaud Mourier
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, 50931 Cologne, Germany
- Université de Bordeaux and the Centre National de la Recherche Scientifique, Institut de Biochimie et Génétique Cellulaires UMR 5095, Saint-Saëns, F-33077 Bordeaux, France
| | - Stefan J. Siira
- Harry Perkins Institute of Medical Research, Centre for Medical Research and School of Chemistry and Biochemistry, The University of Western Australia, Perth 6009, Australia
| | - Nina A. Bonekamp
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, 50931 Cologne, Germany
| | - Ulla Neumann
- Central Microscopy, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
| | - Aleksandra Filipovska
- Harry Perkins Institute of Medical Research, Centre for Medical Research and School of Chemistry and Biochemistry, The University of Western Australia, Perth 6009, Australia
| | - Paola Loguercio Polosa
- Department of Biosciences, Biotechnologies, and Biopharmaceutics, University of Bari Aldo Moro, 70125 Bari, Italy
| | - Claes M. Gustafsson
- Department of Medical Biochemistry and Cell Biology, Göteborgs Universitet, 40530 Göteborg, Sweden
| | - Nils-Göran Larsson
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, 50931 Cologne, Germany
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden
| |
Collapse
|
11
|
Abstract
Mitochondria and peroxisomes are ubiquitous subcellular organelles that fulfill essential metabolic functions, rendering them indispensable for human development and health. Both are highly dynamic organelles that can undergo remarkable changes in morphology and number to accomplish cellular needs. While mitochondrial dynamics are also regulated by frequent fusion events, the fusion of mature peroxisomes in mammalian cells remained a matter of debate. In our recent study, we clarified systematically that there is no complete fusion of mature peroxisomes analogous to mitochondria. Moreover, in contrast to key division components such as DLP1, Fis1 or Mff, mitochondrial fusion proteins were not localized to peroxisomes. However, we discovered and characterized novel transient, complex interactions between individual peroxisomes which may contribute to the homogenization of the often heterogeneous peroxisomal compartment, e.g., by distribution of metabolites, signals or other “molecular information” via interperoxisomal contact sites.
Collapse
Affiliation(s)
- Nina A Bonekamp
- Centre for Cell Biology & Dept. of Biology; University of Aveiro; Campus Universitário de Santiago; Portugal
| | | |
Collapse
|
12
|
Bonekamp NA, Grille S, Cardoso MJ, Almeida M, Aroso M, Gomes S, Magalhaes AC, Ribeiro D, Islinger M, Schrader M. Self-interaction of human Pex11pβ during peroxisomal growth and division. PLoS One 2013; 8:e53424. [PMID: 23308220 PMCID: PMC3538539 DOI: 10.1371/journal.pone.0053424] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 11/28/2012] [Indexed: 12/15/2022] Open
Abstract
Pex11 proteins are involved in membrane elongation and division processes associated with the multiplication of peroxisomes. Human Pex11pβ has recently been linked to a new disorder affecting peroxisome morphology and dynamics. Here, we have analyzed the exact membrane topology of Pex11pβ. Studies with an epitope-specific antibody and protease protection assays show that Pex11pβ is an integral membrane protein with two transmembrane domains flanking an internal region exposed to the peroxisomal matrix and N- and C-termini facing the cytosol. A glycine-rich internal region within Pex11pβ is dispensable for peroxisome membrane elongation and division. However, we demonstrate that an amphipathic helix (Helix 2) within the first N-terminal 40 amino acids is crucial for membrane elongation and self-interaction of Pex11pβ. Interestingly, we find that Pex11pβ self-interaction strongly depends on the detergent used for solubilization. We also show that N-terminal cysteines are not essential for membrane elongation, and that putative N-terminal phosphorylation sites are dispensable for Pex11pβ function. We propose that self-interaction of Pex11pβ regulates its membrane deforming activity in conjunction with membrane lipids.
Collapse
Affiliation(s)
- Nina A. Bonekamp
- Centre for Cell Biology and Department of Biology, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal
| | - Sandra Grille
- Centre for Cell Biology and Department of Biology, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal
| | - Maria Joao Cardoso
- Centre for Cell Biology and Department of Biology, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal
| | - Monica Almeida
- Centre for Cell Biology and Department of Biology, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal
| | - Miguel Aroso
- Centre for Cell Biology and Department of Biology, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal
| | - Silvia Gomes
- Centre for Cell Biology and Department of Biology, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal
| | - Ana Cristina Magalhaes
- Centre for Cell Biology and Department of Biology, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal
| | - Daniela Ribeiro
- Centre for Cell Biology and Department of Biology, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal
| | - Markus Islinger
- Centre for Cell Biology and Department of Biology, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal
| | - Michael Schrader
- Centre for Cell Biology and Department of Biology, University of Aveiro, Campus Universitário de Santiago, Aveiro, Portugal
- College of Life and Environmental Sciences, Biosciences, University of Exeter, Exeter, Devon, United Kingdom
- * E-mail:
| |
Collapse
|
13
|
Bonekamp NA, Sampaio P, de Abreu FV, Lüers GH, Schrader M. Transient complex interactions of mammalian peroxisomes without exchange of matrix or membrane marker proteins. Traffic 2012; 13:960-78. [PMID: 22435684 DOI: 10.1111/j.1600-0854.2012.01356.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Revised: 03/18/2012] [Accepted: 03/21/2012] [Indexed: 11/29/2022]
Abstract
Peroxisomes and mitochondria show a much closer interrelationship than previously anticipated. They co-operate in the metabolism of fatty acids and reactive oxygen species, but also share components of their fission machinery. If peroxisomes - like mitochondria - also fuse in mammalian cells is a matter of debate and was not yet systematically investigated. To examine potential peroxisomal fusion and interactions in mammalian cells, we established an in vivo fusion assay based on hybridoma formation by cell fusion. Fluorescence microscopy in time course experiments revealed a merge of different peroxisomal markers in fused cells. However, live cell imaging revealed that peroxisomes were engaged in transient and long-term contacts, without exchanging matrix or membrane markers. Computational analysis showed that transient peroxisomal interactions are complex and can potentially contribute to the homogenization of the peroxisomal compartment. However, peroxisomal interactions do not increase after fatty acid or H(2) O(2) treatment. Additionally, we provide the first evidence that mitochondrial fusion proteins do not localize to peroxisomes. We conclude that mammalian peroxisomes do not fuse with each other in a mechanism similar to mitochondrial fusion. However, they show an extensive degree of interaction, the implication of which is discussed.
Collapse
Affiliation(s)
- Nina A Bonekamp
- Centre for Cell Biology and Department of Biology, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | | | | | | | | |
Collapse
|
14
|
Bonekamp NA, Vormund K, Jacob R, Schrader M. Dynamin-like protein 1 at the Golgi complex: A novel component of the sorting/targeting machinery en route to the plasma membrane. Exp Cell Res 2010; 316:3454-67. [DOI: 10.1016/j.yexcr.2010.07.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2010] [Revised: 07/25/2010] [Accepted: 07/29/2010] [Indexed: 12/23/2022]
|
15
|
Abstract
Reactive oxygen species (ROS) can surely be considered as multifunctional biofactors within the cell. They are known to participate in regular cell functions, for example, as signal mediators, but overproduction under oxidative stress conditions leads to deleterious cellular effects, cell death and diverse pathological conditions. Peroxisomal function has long been linked to oxygen metabolism due to the high concentration of H(2)O(2)-generating oxidases in peroxisomes and their set of antioxidant enzymes, especially catalase. Still, mitochondria have been very much placed in the centre of ROS metabolism and oxidative stress. This review discusses novel findings concerning the relationship between ROS and peroxisomes, as they revealed to be a key player in the dynamic spin of ROS metabolism and oxidative injury. An overview of ROS generating enzymes as well as their antioxidant counterparts will be given, exemplifying the precise fine-tuning between the opposing systems. Various conditions in which the balance between generation and scavenging of ROS in peroxisomes is perturbed, for example, exogenous manipulation, ageing and peroxisomal disorders, are addressed. Furthermore, peroxisome-derived oxidative stress and its effect on mitochondria (and vice versa) are discussed, highlighting the close interrelationship of both organelles.
Collapse
Affiliation(s)
- Nina A Bonekamp
- Centre for Cell Biology and Department of Biology, University of Aveiro, Aveiro, Portugal
| | | | | | | |
Collapse
|
16
|
Camões F, Bonekamp NA, Delille HK, Schrader M. Organelle dynamics and dysfunction: A closer link between peroxisomes and mitochondria. J Inherit Metab Dis 2009; 32:163-80. [PMID: 19067229 DOI: 10.1007/s10545-008-1018-3] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Revised: 10/30/2008] [Accepted: 11/04/2008] [Indexed: 12/23/2022]
Abstract
Mitochondria and peroxisomes are ubiquitous subcellular organelles, which fulfil an indispensable role in the cellular metabolism of higher eukaryotes. Moreover, they are highly dynamic and display large plasticity. There is growing evidence now that both organelles exhibit a closer interrelationship than previously appreciated. This connection includes metabolic cooperations and cross-talk, a novel putative mitochondria-to-peroxisome vesicular trafficking pathway, as well as an overlap in key components of their fission machinery. Thus, peroxisomal alterations in metabolism, biogenesis, dynamics and proliferation can potentially influence mitochondrial functions, and vice versa. In this review, we present the latest progress in the emerging field of peroxisomal and mitochondrial interrelationship with a particular emphasis on organelle dynamics and its implication in diseases.
Collapse
Affiliation(s)
- F Camões
- Centre for Cell Biology & Department of Biology, University of Aveiro, 3810-193, Aveiro, Portugal
| | | | | | | |
Collapse
|
17
|
Gomez-Lazaro M, Bonekamp NA, Galindo MF, Jordán J, Schrader M. 6-Hydroxydopamine (6-OHDA) induces Drp1-dependent mitochondrial fragmentation in SH-SY5Y cells. Free Radic Biol Med 2008; 44:1960-9. [PMID: 18395527 DOI: 10.1016/j.freeradbiomed.2008.03.009] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2007] [Revised: 02/21/2008] [Accepted: 03/11/2008] [Indexed: 11/30/2022]
Abstract
Mitochondrial alterations have been associated with the cytotoxic effect of 6-hydroxydopamine (6-OHDA), a widely used neurotoxin to study Parkinson's disease. Herein we studied the potential effects of 6-OHDA on mitochondrial morphology in SH-SY5Y neuroblastoma cells. By immunofluorescence and time-lapse fluorescence microscopy we demonstrated that 6-OHDA induced profound mitochondrial fragmentation in SH-SY5Y cells, an event that was similar to mitochondrial fission induced by overexpression of Fis1p, a membrane adaptor for the dynamin-related protein 1 (DLP1/Drp1). 6-OHDA failed to induce any changes in peroxisome morphology. Biochemical experiments revealed that 6-OHDA-induced mitochondrial fragmentation is an early event preceding the collapse of the mitochondrial membrane potential and cytochrome c release in SH-SY5Y cells. Silencing of DLP1/Drp1, which is involved in mitochondrial and peroxisomal fission, prevented 6-OHDA-induced fragmentation of mitochondria. Furthermore, in cells silenced for Drp1, 6-OHDA-induced cell death was reduced, indicating that a block in mitochondrial fission protects SH-SY5Y cells against 6-OHDA toxicity. Experiments in mouse embryonic fibroblasts deficient in Bax or p53 revealed that both proteins are not essential for 6-OHDA-induced mitochondrial fragmentation. Our data demonstrate for the first time an involvement of mitochondrial fragmentation and Drp1 function in 6-OHDA-induced apoptosis.
Collapse
Affiliation(s)
- Maria Gomez-Lazaro
- Grupo de Neurofarmacología, Department Ciencias Médicas, Facultad de Medicina, Universidad de Castilla-La Mancha-Centro Regional de Investigaciones Biomédicas, Albacete, Spain
| | | | | | | | | |
Collapse
|
18
|
Delille HK, Bonekamp NA, Schrader M. Peroxisomes and disease - an overview. Int J Biomed Sci 2006; 2:308-14. [PMID: 23674998 PMCID: PMC3614646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Peroxisomes are indispensable for human health and development. They represent ubiquitous subcellular organelles which compartmentalize enzymes responsible for several crucial metabolic processes such as β-oxidation of specific fatty acids, biosynthesis of ether phospholipids and metabolism of reactive oxygen species. Peroxisomes are highly flexible organelles that rapidly assemble, multiply and degrade in response to metabolic needs. Basic research on the biogenesis of peroxisomes and their metabolic functions have improved our knowledge about their crucial role in several inherited disorders and in other pathophysiological conditions. The goal of this review is to give a comprehensive overview of the role of peroxisomes in disease. Besides the genetic peroxisomal disorders in humans, the role of peroxisomes in carcinogenesis and in situations related to oxidative stress such as inflammation, ischemia-reperfusion, and diabetes will be addressed.
Collapse
|
19
|
Abstract
The mammalian dynamin-like protein DLP1/Drp1 has been shown to mediate both mitochondrial and peroxisomal fission. In this study, we have examined whether hFis1, a mammalian homologue of yeast Fis1, which has been shown to participate in mitochondrial fission by an interaction with DLP1/Drp1, is also involved in peroxisomal growth and division. We show that hFis1 localizes to peroxisomes in addition to mitochondria. Through differential tagging and deletion experiments, we demonstrate that the transmembrane domain and the short C-terminal tail of hFis1 is both necessary and sufficient for its targeting to peroxisomes and mitochondria, whereas the N-terminal region is required for organelle fission. hFis1 promotes peroxisome division upon ectopic expression, whereas silencing of Fis1 by small interfering RNA inhibited fission and caused tubulation of peroxisomes. These findings provide the first evidence for a role of Fis1 in peroxisomal fission and suggest that the fission machinery of mitochondria and peroxisomes shares common components.
Collapse
Affiliation(s)
- Annett Koch
- Department of Cell Biology and Cell Pathology, University of Marburg, 35037 Marburg, Germany
| | | | | | | | | |
Collapse
|