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Ruan K, Bai G, Fang Y, Li D, Li T, Liu X, Lu B, Lu Q, Songyang Z, Sun S, Wang Z, Zhang X, Zhou W, Zhang H. Biomolecular condensates and disease pathogenesis. SCIENCE CHINA. LIFE SCIENCES 2024:10.1007/s11427-024-2661-3. [PMID: 39037698 DOI: 10.1007/s11427-024-2661-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Accepted: 06/21/2024] [Indexed: 07/23/2024]
Abstract
Biomolecular condensates or membraneless organelles (MLOs) formed by liquid-liquid phase separation (LLPS) divide intracellular spaces into discrete compartments for specific functions. Dysregulation of LLPS or aberrant phase transition that disturbs the formation or material states of MLOs is closely correlated with neurodegeneration, tumorigenesis, and many other pathological processes. Herein, we summarize the recent progress in development of methods to monitor phase separation and we discuss the biogenesis and function of MLOs formed through phase separation. We then present emerging proof-of-concept examples regarding the disruption of phase separation homeostasis in a diverse array of clinical conditions including neurodegenerative disorders, hearing loss, cancers, and immunological diseases. Finally, we describe the emerging discovery of chemical modulators of phase separation.
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Affiliation(s)
- Ke Ruan
- The First Affiliated Hospital & School of Life Sciences, Ministry of Education Key Laboratory for Membrane-less Organelles & Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230027, China.
| | - Ge Bai
- Nanhu Brain-computer Interface Institute, Hangzhou, 311100, China.
- Department of Neurology of Second Affiliated Hospital and School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China.
| | - Yanshan Fang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Dan Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200030, China.
| | - Tingting Li
- Department of Biomedical Informatics, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China.
| | - Xingguo Liu
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China.
- Joint School of Life Sciences, Guangzhou Medical University, Guangzhou, 510000, China.
| | - Boxun Lu
- Neurology Department at Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, School of Life Sciences, Fudan University, Shanghai, 200433, China.
| | - Qing Lu
- Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Bio-X Institutes, Shanghai Jiao Tong University, Shanghai, 200030, China.
| | - Zhou Songyang
- State Key Laboratory of Biocontrol, MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510275, China.
| | - Shuguo Sun
- Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Zheng Wang
- The Second Affiliated Hospital, School of Basic Medical Sciences, Institute of Biomedical Innovation, Jiangxi Medical College, Nanchang University, Nanchang, 330031, China.
| | - Xin Zhang
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, 310024, China.
| | - Wen Zhou
- Department of Immunology and Microbiology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China.
| | - Hong Zhang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
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2
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Zhang M, Feng N, Peng Z, Thapa D, Stoner MW, Manning JR, McTiernan CF, Yang X, Jurczak MJ, Guimaraes D, Rao K, Shiva S, Kaufman BA, Sack MN, Scott I. Reduced acetylation of TFAM promotes bioenergetic dysfunction in the failing heart. iScience 2023; 26:106942. [PMID: 37305705 PMCID: PMC10250906 DOI: 10.1016/j.isci.2023.106942] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 04/11/2023] [Accepted: 05/19/2023] [Indexed: 06/13/2023] Open
Abstract
General control of amino acid synthesis 5-like 1 (GCN5L1) was previously identified as a key regulator of protein lysine acetylation in mitochondria. Subsequent studies demonstrated that GCN5L1 regulates the acetylation status and activity of mitochondrial fuel substrate metabolism enzymes. However, the role of GCN5L1 in response to chronic hemodynamic stress is largely unknown. Here, we show that cardiomyocyte-specific GCN5L1 knockout mice (cGCN5L1 KO) display exacerbated heart failure progression following transaortic constriction (TAC). Mitochondrial DNA and protein levels were decreased in cGCN5L1 KO hearts after TAC, and isolated neonatal cardiomyocytes with reduced GCN5L1 expression had lower bioenergetic output in response to hypertrophic stress. Loss of GCN5L1 expression led to a decrease in the acetylation status of mitochondrial transcription factor A (TFAM) after TAC in vivo, which was linked to a reduction in mtDNA levels in vitro. Together, these data suggest that GCN5L1 may protect from hemodynamic stress by maintaining mitochondrial bioenergetic output.
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Affiliation(s)
- Manling Zhang
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Pittsburgh Veteran Affairs Medical Center, Pittsburgh, PA 15240, USA
| | - Ning Feng
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Pittsburgh Veteran Affairs Medical Center, Pittsburgh, PA 15240, USA
| | - Zishan Peng
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Dharendra Thapa
- Division of Exercise Physiology, West Virginia University School of Medicine, Morgantown, WV 26506, USA
| | - Michael W. Stoner
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Center for Metabolism and Mitochondrial Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Janet R. Manning
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Center for Metabolism and Mitochondrial Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Charles F. McTiernan
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Xue Yang
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Michael J. Jurczak
- Center for Metabolism and Mitochondrial Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Danielle Guimaraes
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Krithika Rao
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Sruti Shiva
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Brett A. Kaufman
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Center for Metabolism and Mitochondrial Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Michael N. Sack
- Intramural Research Program, National Heart, Lung, and Blood Institute, Bethesda, MD 20892, USA
| | - Iain Scott
- Vascular Medicine Institute, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Center for Metabolism and Mitochondrial Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
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3
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Lv T, Zhang Y, Ji X, Sun S, Xu L, Ma W, Liu Y, Wan Q. GCN5L1-mediated TFAM acetylation at K76 participates in mitochondrial biogenesis in acute kidney injury. J Transl Med 2022; 20:571. [PMID: 36474281 PMCID: PMC9724393 DOI: 10.1186/s12967-022-03782-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 11/19/2022] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Mitochondrial dysfunction is an important pathogenic event in acute kidney injury (AKI). GCN5L1 is a specific acetyltransferase in mitochondria, which regulates glucose and fatty acid metabolism. However, the role of GCN5L1 in mitochondrial dysfunction and the pathogenesis of ischemic AKI are not fully understood. METHODS The protein level of GCN5L1 was detected by western blot assay. Acetylated proteomics was used to explore the level of acetylated TFAM. Duolink proximity ligation assay and co-immunoprecipitation were used to detect the interaction of TFAM and translocase of outer membrane 70 (TOM70). mtDNA copy number, the expression of mitochondrial electron transport chain complexes, the number and morphology of mitochondria were measured. The renal injury of AKI mice was reflected by the levels of creatinine and urea nitrogen and the pathological changes of renal tissue. RESULTS We showed that GCN5L1 was highly expressed in vivo and in vitro and renal tubules specific knockdown of GCN5L1 could effectively attenuate AKI-induced mitochondrial impairment. Besides, acetylated proteomics revealed that acetylated TFAM was significantly upregulated in AKI mice kidney, which reminded us that TFAM might be an acetylating substrate of GCN5L1. Mechanistically, we evidenced that GCN5L1 could acetylate TFAM at its K76 site and subsequently inhibited its binding to TOM70, thereby reducing TFAM import into mitochondria and mitochondrial biogenesis. Clinically, GCN5L1 and acetylated TFAM were positively correlated with disease severity (all p < 0.05). CONCLUSIONS In sum, these data demonstrated an unrecognized regulating mechanism of GCN5L1 on TFAM acetylation and its intracellular trafficking, and a potential intervening target for AKI associated mitochondrial disorders as well.
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Affiliation(s)
- Tingting Lv
- grid.460018.b0000 0004 1769 9639Department of Cancer Center, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021 Shandong China
| | - Yu Zhang
- grid.27255.370000 0004 1761 1174Department of Allergy, Department of Pulmonary and Critical Care Medicine, Shandong Provincial Hospital, Shandong University, Jinan, 250021 Shandong China
| | - XingZhao Ji
- grid.460018.b0000 0004 1769 9639Department of Allergy, Department of Pulmonary and Critical Care Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021 Shandong China ,grid.410587.fShandong Key Laboratory of Infections Respiratory Disease, Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong China
| | - Shengnan Sun
- grid.27255.370000 0004 1761 1174Center of Cell Metabolism and Disease, Jinan Central Hospital, Shandong University, Jinan, 250012 Shandong China
| | - Li Xu
- grid.460018.b0000 0004 1769 9639Department of Allergy, Department of Pulmonary and Critical Care Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021 Shandong China ,grid.410587.fShandong Key Laboratory of Infections Respiratory Disease, Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong China
| | - Weixia Ma
- grid.460018.b0000 0004 1769 9639Department of Allergy, Department of Pulmonary and Critical Care Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021 Shandong China ,grid.410587.fShandong Key Laboratory of Infections Respiratory Disease, Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong China
| | - Yi Liu
- grid.460018.b0000 0004 1769 9639Department of Allergy, Department of Pulmonary and Critical Care Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250021 Shandong China ,grid.410587.fShandong Key Laboratory of Infections Respiratory Disease, Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong China
| | - Qiang Wan
- grid.27255.370000 0004 1761 1174Center of Cell Metabolism and Disease, Jinan Central Hospital, Shandong University, Jinan, 250012 Shandong China
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Lee JH, Hussain M, Kim EW, Cheng SJ, Leung AKL, Fakouri NB, Croteau DL, Bohr VA. Mitochondrial PARP1 regulates NAD +-dependent poly ADP-ribosylation of mitochondrial nucleoids. Exp Mol Med 2022; 54:2135-2147. [PMID: 36473936 PMCID: PMC9794712 DOI: 10.1038/s12276-022-00894-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 08/23/2022] [Accepted: 09/19/2022] [Indexed: 12/12/2022] Open
Abstract
PARPs play fundamental roles in multiple DNA damage recognition and repair pathways. Persistent nuclear PARP activation causes cellular NAD+ depletion and exacerbates cellular aging. However, very little is known about mitochondrial PARP (mtPARP) and poly ADP-ribosylation (PARylation). The existence of mtPARP is controversial, and the biological roles of mtPARP-induced mitochondrial PARylation are unclear. Here, we demonstrate the presence of PARP1 and PARylation in purified mitochondria. The addition of the PARP1 substrate NAD+ to isolated mitochondria induced PARylation, which was suppressed by treatment with the inhibitor olaparib. Mitochondrial PARylation was also evaluated by enzymatic labeling of terminal ADP-ribose (ELTA). To further confirm the presence of mtPARP1, we evaluated mitochondrial nucleoid PARylation by ADP ribose-chromatin affinity purification (ADPr-ChAP) and PARP1 chromatin immunoprecipitation (ChIP). We observed that NAD+ stimulated PARylation and TFAM occupancy on the mtDNA regulatory region D-loop, inducing mtDNA transcription. These findings suggest that PARP1 is integrally involved in mitochondrial PARylation and that NAD+-dependent mtPARP1 activity contributes to mtDNA transcriptional regulation.
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Affiliation(s)
- Jong-Hyuk Lee
- Section on DNA Repair, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA
- Department of Biomedical Sciences, Mercer University School of Medicine, Savannah, GA, 31404, USA
| | - Mansoor Hussain
- Section on DNA Repair, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Edward W Kim
- Section on DNA Repair, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Shang-Jung Cheng
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Anthony K L Leung
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, 21205, USA
- Departments of Oncology, Genetics Medicine, Molecular Biology & Genetics, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Nima Borhan Fakouri
- Section on DNA Repair, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Deborah L Croteau
- Section on DNA Repair, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA
- Computational Biology and Genomic Core Facility, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Vilhelm A Bohr
- Section on DNA Repair, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA.
- Danish Center for Healthy Aging, University of Copenhagen, 2200, Copenhagen, Denmark.
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5
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Marmolejo-Garza A, Medeiros-Furquim T, Rao R, Eggen BJL, Boddeke E, Dolga AM. Transcriptomic and epigenomic landscapes of Alzheimer's disease evidence mitochondrial-related pathways. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119326. [PMID: 35839870 DOI: 10.1016/j.bbamcr.2022.119326] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 07/06/2022] [Accepted: 07/07/2022] [Indexed: 02/06/2023]
Abstract
Alzheimers disease (AD) is the main cause of dementia and it is defined by cognitive decline coupled to extracellular deposit of amyloid-beta protein and intracellular hyperphosphorylation of tau protein. Historically, efforts to target such hallmarks have failed in numerous clinical trials. In addition to these hallmark-targeted approaches, several clinical trials focus on other AD pathological processes, such as inflammation, mitochondrial dysfunction, and oxidative stress. Mitochondria and mitochondrial-related mechanisms have become an attractive target for disease-modifying strategies, as mitochondrial dysfunction prior to clinical onset has been widely described in AD patients and AD animal models. Mitochondrial function relies on both the nuclear and mitochondrial genome. Findings from omics technologies have shed light on AD pathophysiology at different levels (e.g., epigenome, transcriptome and proteome). Most of these studies have focused on the nuclear-encoded components. The first part of this review provides an updated overview of the mechanisms that regulate mitochondrial gene expression and function. The second part of this review focuses on evidence of mitochondrial dysfunction in AD. We have focused on published findings and datasets that study AD. We analyzed published data and provide examples for mitochondrial-related pathways. These pathways are strikingly dysregulated in AD neurons and glia in sex-, cell- and disease stage-specific manners. Analysis of mitochondrial omics data highlights the involvement of mitochondria in AD, providing a rationale for further disease modeling and drug targeting.
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Affiliation(s)
- Alejandro Marmolejo-Garza
- Department of Molecular Pharmacology, Faculty of Science and Engineering, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, the Netherlands; Department of Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, Faculty of Medical Sciences, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Tiago Medeiros-Furquim
- Department of Molecular Pharmacology, Faculty of Science and Engineering, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, the Netherlands; Department of Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, Faculty of Medical Sciences, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Ramya Rao
- Department of Molecular Pharmacology, Faculty of Science and Engineering, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, the Netherlands
| | - Bart J L Eggen
- Department of Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, Faculty of Medical Sciences, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Erik Boddeke
- Department of Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, Faculty of Medical Sciences, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands; Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen N, Denmark.
| | - Amalia M Dolga
- Department of Molecular Pharmacology, Faculty of Science and Engineering, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, the Netherlands.
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Zhou Z, Hagopian K, López-Domínguez JA, Kim K, Jasoliya M, Roberts MN, Cortopassi GA, Showalter MR, Roberts BS, González-Reyes JA, Baar K, Rutkowsky J, Ramsey JJ. A ketogenic diet impacts markers of mitochondrial mass in a tissue specific manner in aged mice. Aging (Albany NY) 2021; 13:7914-7930. [PMID: 33735837 PMCID: PMC8034930 DOI: 10.18632/aging.202834] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 02/16/2021] [Indexed: 12/14/2022]
Abstract
Declines in mitochondrial mass are thought to be a hallmark of mammalian aging, and a ketogenic diet (KD) may prevent the age-related decreases in mitochondrial content. The objective of this study was to investigate the impact of a KD on markers of mitochondrial mass. Mice were fed an isocaloric control diet (CD) or KD from 12 months of age. Tissues were collected after 1 month and 14 months of intervention, and a panel of commonly used markers of mitochondrial mass (mitochondrial enzyme activities and levels, mitochondrial to nuclear DNA ratio, and cardiolipin content) were measured. Our results showed that a KD stimulated activities of marker mitochondrial enzymes including citrate synthase, Complex I, and Complex IV in hindlimb muscle in aged mice. KD also increased the activity of citrate synthase and prevented an age-related decrease in Complex IV activity in aged brain. No other markers were increased in these tissues. Furthermore, the impacts of a KD on liver and kidney were mixed with no pattern indicative of a change in mitochondrial mass. In conclusion, results of the present study suggest that a KD induces tissue-specific changes in mitochondrial enzyme activities, or structure, rather than global changes in mitochondrial mass across tissues.
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Affiliation(s)
- Zeyu Zhou
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Kevork Hagopian
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - José A López-Domínguez
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Kyoungmi Kim
- Department of Public Health Sciences, School of Medicine, University of California, Davis, CA 95617, USA
| | - Mittal Jasoliya
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Megan N Roberts
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Gino A Cortopassi
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Megan R Showalter
- NIH-West Coast Metabolomics Center, University of California, Davis, CA 95616, USA
| | - Bryan S Roberts
- NIH-West Coast Metabolomics Center, University of California, Davis, CA 95616, USA
| | - José A González-Reyes
- Department of Cell Biology, Physiology and Immunology, Campus de Excelencia Internacional Agroalimentario, ceiA3, University of Córdoba, Córdoba, Spain
| | - Keith Baar
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, CA 95616, USA
| | - Jennifer Rutkowsky
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Jon J Ramsey
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
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7
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Basu U, Bostwick AM, Das K, Dittenhafer-Reed KE, Patel SS. Structure, mechanism, and regulation of mitochondrial DNA transcription initiation. J Biol Chem 2020; 295:18406-18425. [PMID: 33127643 PMCID: PMC7939475 DOI: 10.1074/jbc.rev120.011202] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 10/29/2020] [Indexed: 12/14/2022] Open
Abstract
Mitochondria are specialized compartments that produce requisite ATP to fuel cellular functions and serve as centers of metabolite processing, cellular signaling, and apoptosis. To accomplish these roles, mitochondria rely on the genetic information in their small genome (mitochondrial DNA) and the nucleus. A growing appreciation for mitochondria's role in a myriad of human diseases, including inherited genetic disorders, degenerative diseases, inflammation, and cancer, has fueled the study of biochemical mechanisms that control mitochondrial function. The mitochondrial transcriptional machinery is different from nuclear machinery. The in vitro re-constituted transcriptional complexes of Saccharomyces cerevisiae (yeast) and humans, aided with high-resolution structures and biochemical characterizations, have provided a deeper understanding of the mechanism and regulation of mitochondrial DNA transcription. In this review, we will discuss recent advances in the structure and mechanism of mitochondrial transcription initiation. We will follow up with recent discoveries and formative findings regarding the regulatory events that control mitochondrial DNA transcription, focusing on those involved in cross-talk between the mitochondria and nucleus.
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Affiliation(s)
- Urmimala Basu
- Department of Biochemistry and Molecular Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, New Jersey, USA; Graduate School of Biomedical Sciences, Rutgers Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | | | - Kalyan Das
- Department of Microbiology, Immunology, and Transplantation, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | | | - Smita S Patel
- Department of Biochemistry and Molecular Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, New Jersey, USA.
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8
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Vozáriková V, Kunová N, Bauer JA, Frankovský J, Kotrasová V, Procházková K, Džugasová V, Kutejová E, Pevala V, Nosek J, Tomáška Ľ. Mitochondrial HMG-Box Containing Proteins: From Biochemical Properties to the Roles in Human Diseases. Biomolecules 2020; 10:biom10081193. [PMID: 32824374 PMCID: PMC7463775 DOI: 10.3390/biom10081193] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 08/11/2020] [Accepted: 08/13/2020] [Indexed: 12/14/2022] Open
Abstract
Mitochondrial DNA (mtDNA) molecules are packaged into compact nucleo-protein structures called mitochondrial nucleoids (mt-nucleoids). Their compaction is mediated in part by high-mobility group (HMG)-box containing proteins (mtHMG proteins), whose additional roles include the protection of mtDNA against damage, the regulation of gene expression and the segregation of mtDNA into daughter organelles. The molecular mechanisms underlying these functions have been identified through extensive biochemical, genetic, and structural studies, particularly on yeast (Abf2) and mammalian mitochondrial transcription factor A (TFAM) mtHMG proteins. The aim of this paper is to provide a comprehensive overview of the biochemical properties of mtHMG proteins, the structural basis of their interaction with DNA, their roles in various mtDNA transactions, and the evolutionary trajectories leading to their rapid diversification. We also describe how defects in the maintenance of mtDNA in cells with dysfunctional mtHMG proteins lead to different pathologies at the cellular and organismal level.
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Affiliation(s)
- Veronika Vozáriková
- Department of Genetics, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, Mlynská dolina B-1, 842 15 Bratislava, Slovakia; (V.V.); (J.F.); (K.P.); (V.D.)
| | - Nina Kunová
- Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia; (N.K.); (J.A.B.); (V.K.); (E.K.); (V.P.)
| | - Jacob A. Bauer
- Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia; (N.K.); (J.A.B.); (V.K.); (E.K.); (V.P.)
| | - Ján Frankovský
- Department of Genetics, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, Mlynská dolina B-1, 842 15 Bratislava, Slovakia; (V.V.); (J.F.); (K.P.); (V.D.)
| | - Veronika Kotrasová
- Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia; (N.K.); (J.A.B.); (V.K.); (E.K.); (V.P.)
| | - Katarína Procházková
- Department of Genetics, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, Mlynská dolina B-1, 842 15 Bratislava, Slovakia; (V.V.); (J.F.); (K.P.); (V.D.)
| | - Vladimíra Džugasová
- Department of Genetics, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, Mlynská dolina B-1, 842 15 Bratislava, Slovakia; (V.V.); (J.F.); (K.P.); (V.D.)
| | - Eva Kutejová
- Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia; (N.K.); (J.A.B.); (V.K.); (E.K.); (V.P.)
| | - Vladimír Pevala
- Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia; (N.K.); (J.A.B.); (V.K.); (E.K.); (V.P.)
| | - Jozef Nosek
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, Mlynská dolina CH-1, 842 15 Bratislava, Slovakia;
| | - Ľubomír Tomáška
- Department of Genetics, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, Mlynská dolina B-1, 842 15 Bratislava, Slovakia; (V.V.); (J.F.); (K.P.); (V.D.)
- Correspondence: ; Tel.: +421-2-90149-433
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9
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Fang Y, Akimoto M, Mayanagi K, Hatano A, Matsumoto M, Matsuda S, Yasukawa T, Kang D. Chemical acetylation of mitochondrial transcription factor A occurs on specific lysine residues and affects its ability to change global DNA topology. Mitochondrion 2020; 53:99-108. [PMID: 32439622 DOI: 10.1016/j.mito.2020.05.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 05/08/2020] [Accepted: 05/14/2020] [Indexed: 12/20/2022]
Abstract
Chemical acetylation is postulated to occur in mitochondria. Mitochondrial transcription factor A (TFAM or mtTFA), a mitochondrial transcription initiation factor as well as the major mitochondrial nucleoid protein coating the entire mitochondrial genome, is proposed to be acetylated in animals and cultured cells. This study investigated the properties of human TFAM, in conjunction with the mechanism and effects of TFAM acetylation in vitro. Using highly purified recombinant human TFAM and 3 kb circular DNA as a downsized mtDNA model, we studied how the global TFAM-DNA interaction is affected/regulated by the quantitative TFAM-DNA relationship and TFAM acetylation. Results showed that the TFAM-DNA ratio strictly affects the TFAM property to unwind circular DNA in the presence of topoisomerase I. Mass spectrometry analysis showed that in vitro chemical acetylation of TFAM with acetyl-coenzyme A occurs preferentially on specific lysine residues, including those reported to be acetylated in exogenously expressed TFAM in cultured human cells, indicating that chemical acetylation plays a crucial role in TFAM acetylation in mitochondria. Intriguingly, the modification significantly decreased TFAM's DNA-unwinding ability, while its DNA-binding ability was largely unaffected. Altogether, we propose TFAM is chemically acetylated in vivo, which could change mitochondrial DNA topology, leading to copy number and gene expression modulation.
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Affiliation(s)
- Yuan Fang
- Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka 812-8582, Japan
| | - Masaru Akimoto
- Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka 812-8582, Japan; Department of Clinical Chemistry and Laboratory Medicine, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka 812-8582, Japan
| | - Kouta Mayanagi
- Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka 812-8582, Japan
| | - Atsushi Hatano
- Department of Omics and Systems Biology, Graduate School of Medical and Dental Sciences, Niigata University, 757 Ichibancho, Asahimachi-dori, Chuo-ku, Niigata-shi, Niigata 951-8510, Japan
| | - Masaki Matsumoto
- Department of Omics and Systems Biology, Graduate School of Medical and Dental Sciences, Niigata University, 757 Ichibancho, Asahimachi-dori, Chuo-ku, Niigata-shi, Niigata 951-8510, Japan
| | - Shigeru Matsuda
- Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka 812-8582, Japan
| | - Takehiro Yasukawa
- Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka 812-8582, Japan.
| | - Dongchon Kang
- Department of Clinical Chemistry and Laboratory Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka 812-8582, Japan
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10
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Dong Z, Pu L, Cui H. Mitoepigenetics and Its Emerging Roles in Cancer. Front Cell Dev Biol 2020; 8:4. [PMID: 32039210 PMCID: PMC6989428 DOI: 10.3389/fcell.2020.00004] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 01/08/2020] [Indexed: 12/11/2022] Open
Abstract
In human beings, there is a ∼16,569 bp circular mitochondrial DNA (mtDNA) encoding 22 tRNAs, 12S and 16S rRNAs, 13 polypeptides that constitute the central core of ETC/OxPhos complexes, and some non-coding RNAs. Recently, mtDNA has been shown to have some covalent modifications such as methylation or hydroxylmethylation, which play pivotal epigenetic roles in mtDNA replication and transcription. Post-translational modifications of proteins in mitochondrial nucleoids such as mitochondrial transcription factor A (TFAM) also emerge as essential epigenetic modulations in mtDNA replication and transcription. Post-transcriptional modifications of mitochondrial RNAs (mtRNAs) including mt-rRNAs, mt-tRNAs and mt-mRNAs are important epigenetic modulations. Besides, mtDNA or nuclear DNA (n-DNA)-derived non-coding RNAs also play important roles in the regulation of translation and function of mitochondrial genes. These evidences introduce a novel concept of mitoepigenetics that refers to the study of modulations in the mitochondria that alter heritable phenotype in mitochondria itself without changing the mtDNA sequence. Since mitochondrial dysfunction contributes to carcinogenesis and tumor development, mitoepigenetics is also essential for cancer. Understanding the mode of actions of mitoepigenetics in cancers may shade light on the clinical diagnosis and prevention of these diseases. In this review, we summarize the present study about modifications in mtDNA, mtRNA and nucleoids and modulations of mtDNA/nDNA-derived non-coding RNAs that affect mtDNA translation/function, and overview recent studies of mitoepigenetic alterations in cancer.
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Affiliation(s)
- Zhen Dong
- State Key Laboratory of Silkworm Genome Biology, Institute of Sericulture and Systems Biology, Southwest University, Chongqing, China.,Cancer Center, Medical Research Institute, Southwest University, Chongqing, China.,Engineering Research Center for Cancer Biomedical and Translational Medicine, Southwest University, Chongqing, China.,Chongqing Engineering and Technology Research Center for Silk Biomaterials and Regenerative Medicine, Southwest University, Chongqing, China
| | - Longjun Pu
- Umeå Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Hongjuan Cui
- State Key Laboratory of Silkworm Genome Biology, Institute of Sericulture and Systems Biology, Southwest University, Chongqing, China.,Cancer Center, Medical Research Institute, Southwest University, Chongqing, China.,Engineering Research Center for Cancer Biomedical and Translational Medicine, Southwest University, Chongqing, China.,Chongqing Engineering and Technology Research Center for Silk Biomaterials and Regenerative Medicine, Southwest University, Chongqing, China
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11
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Organization of DNA in Mammalian Mitochondria. Int J Mol Sci 2019; 20:ijms20112770. [PMID: 31195723 PMCID: PMC6600607 DOI: 10.3390/ijms20112770] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 05/29/2019] [Accepted: 06/03/2019] [Indexed: 12/22/2022] Open
Abstract
As with all organisms that must organize and condense their DNA to fit within the limited volume of a cell or a nucleus, mammalian mitochondrial DNA (mtDNA) is packaged into nucleoprotein structures called nucleoids. In this study, we first introduce the general modes of DNA compaction, especially the role of the nucleoid-associated proteins (NAPs) that structure the bacterial chromosome. We then present the mitochondrial nucleoid and the main factors responsible for packaging of mtDNA: ARS- (autonomously replicating sequence-) binding factor 2 protein (Abf2p) in yeast and mitochondrial transcription factor A (TFAM) in mammals. We summarize the single-molecule manipulation experiments on mtDNA compaction and visualization of mitochondrial nucleoids that have led to our current knowledge on mtDNA compaction. Lastly, we discuss the possible regulatory role of DNA packaging by TFAM in DNA transactions such as mtDNA replication and transcription.
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12
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Liu H, Li S, Liu X, Chen Y, Deng H. SIRT3 Overexpression Inhibits Growth of Kidney Tumor Cells and Enhances Mitochondrial Biogenesis. J Proteome Res 2018; 17:3143-3152. [DOI: 10.1021/acs.jproteome.8b00260] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Huan Liu
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systematic Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Siying Li
- University of California, Davis, Davis, California 95616, United States
| | - Xiaohui Liu
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systematic Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yuling Chen
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systematic Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua University−Peking University Joint Center for Life Sciences, Beijing 100084, China
| | - Haiteng Deng
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systematic Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
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13
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King GA, Hashemi Shabestari M, Taris KKH, Pandey AK, Venkatesh S, Thilagavathi J, Singh K, Krishna Koppisetti R, Temiakov D, Roos WH, Suzuki CK, Wuite GJL. Acetylation and phosphorylation of human TFAM regulate TFAM-DNA interactions via contrasting mechanisms. Nucleic Acids Res 2018; 46:3633-3642. [PMID: 29897602 PMCID: PMC5909435 DOI: 10.1093/nar/gky204] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 03/05/2018] [Accepted: 03/08/2018] [Indexed: 01/13/2023] Open
Abstract
Mitochondrial transcription factor A (TFAM) is essential for the maintenance, expression and transmission of mitochondrial DNA (mtDNA). However, mechanisms for the post-translational regulation of TFAM are poorly understood. Here, we show that TFAM is lysine acetylated within its high-mobility-group box 1, a domain that can also be serine phosphorylated. Using bulk and single-molecule methods, we demonstrate that site-specific phosphoserine and acetyl-lysine mimics of human TFAM regulate its interaction with non-specific DNA through distinct kinetic pathways. We show that higher protein concentrations of both TFAM mimics are required to compact DNA to a similar extent as the wild-type. Compaction is thought to be crucial for regulating mtDNA segregation and expression. Moreover, we reveal that the reduced DNA binding affinity of the acetyl-lysine mimic arises from a lower on-rate, whereas the phosphoserine mimic displays both a decreased on-rate and an increased off-rate. Strikingly, the increased off-rate of the phosphoserine mimic is coupled to a significantly faster diffusion of TFAM on DNA. These findings indicate that acetylation and phosphorylation of TFAM can fine-tune TFAM-DNA binding affinity, to permit the discrete regulation of mtDNA dynamics. Furthermore, our results suggest that phosphorylation could additionally regulate transcription by altering the ability of TFAM to locate promoter sites.
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Affiliation(s)
- Graeme A King
- Department of Physics and Astronomy and LaserLaB, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Maryam Hashemi Shabestari
- Department of Physics and Astronomy and LaserLaB, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Kees-Karel H Taris
- Department of Physics and Astronomy and LaserLaB, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Ashutosh K Pandey
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Sundararajan Venkatesh
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Jayapalraja Thilagavathi
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Kamalendra Singh
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
- Department of Molecular Microbiology and Immunology, Christopher Bond Life Sciences Center, University of Missouri School of Medicine, Columbia, MO 65211, USA
- Department of Laboratory Medicine, Division of Clinical Microbiology, Karolinska Institutet, 171 77 Solna, Sweden
| | - Rama Krishna Koppisetti
- Department of Molecular Microbiology and Immunology, Christopher Bond Life Sciences Center, University of Missouri School of Medicine, Columbia, MO 65211, USA
| | - Dmitry Temiakov
- Department of Cell Biology, Rowan University, School of Osteopathic Medicine, Stratford, NJ 08084, USA
| | - Wouter H Roos
- Department of Molecular Biophysics, Zernike Instituut, Rijksuniversiteit Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Carolyn K Suzuki
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Gijs J L Wuite
- Department of Physics and Astronomy and LaserLaB, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
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14
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Kang I, Chu CT, Kaufman BA. The mitochondrial transcription factor TFAM in neurodegeneration: emerging evidence and mechanisms. FEBS Lett 2018; 592:793-811. [PMID: 29364506 PMCID: PMC5851836 DOI: 10.1002/1873-3468.12989] [Citation(s) in RCA: 156] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 01/18/2018] [Accepted: 01/19/2018] [Indexed: 12/30/2022]
Abstract
The mitochondrial transcription factor A, or TFAM, is a mitochondrial DNA (mtDNA)-binding protein essential for genome maintenance. TFAM functions in determining the abundance of the mitochondrial genome by regulating packaging, stability, and replication. More recently, TFAM has been shown to play a central role in the mtDNA stress-mediated inflammatory response. Emerging evidence indicates that decreased mtDNA copy number is associated with several aging-related pathologies; however, little is known about the association of TFAM abundance and disease. In this Review, we evaluate the potential associations of altered TFAM levels or mtDNA copy number with neurodegeneration. We also describe potential mechanisms by which mtDNA replication, transcription initiation, and TFAM-mediated endogenous danger signals may impact mitochondrial homeostasis in Alzheimer, Huntington, Parkinson, and other neurodegenerative diseases.
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Affiliation(s)
- Inhae Kang
- Department of Food Science and Nutrition, Jeju National University, Jeju, Korea
- Division of Cardiology, Vascular Medicine Institute, Department of Medicine Center for Metabolic and Mitochondrial Medicine (C3M), University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Charleen T. Chu
- Department of Pathology, Center for Neuroscience, Pittsburgh Institute for Neurodegenerative Diseases, Conformational Protein Diseases Center, and the McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Brett A. Kaufman
- Division of Cardiology, Vascular Medicine Institute, Department of Medicine Center for Metabolic and Mitochondrial Medicine (C3M), University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
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15
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Lin H, Magrane J, Rattelle A, Stepanova A, Galkin A, Clark EM, Dong YN, Halawani SM, Lynch DR. Early cerebellar deficits in mitochondrial biogenesis and respiratory chain complexes in the KIKO mouse model of Friedreich ataxia. Dis Model Mech 2017; 10:1343-1352. [PMID: 29125827 PMCID: PMC5719255 DOI: 10.1242/dmm.030502] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 08/11/2017] [Indexed: 12/14/2022] Open
Abstract
Friedreich ataxia (FRDA), the most common recessive inherited ataxia, results from deficiency of frataxin, a small mitochondrial protein crucial for iron-sulphur cluster formation and ATP production. Frataxin deficiency is associated with mitochondrial dysfunction in FRDA patients and animal models; however, early mitochondrial pathology in FRDA cerebellum remains elusive. Using frataxin knock-in/knockout (KIKO) mice and KIKO mice carrying the mitoDendra transgene, we show early cerebellar deficits in mitochondrial biogenesis and respiratory chain complexes in this FRDA model. At asymptomatic stages, the levels of PGC-1α (PPARGC1A), the mitochondrial biogenesis master regulator, are significantly decreased in cerebellar homogenates of KIKO mice compared with age-matched controls. Similarly, the levels of the PGC-1α downstream effectors, NRF1 and Tfam, are significantly decreased, suggesting early impaired cerebellar mitochondrial biogenesis pathways. Early mitochondrial deficiency is further supported by significant reduction of the mitochondrial markers GRP75 (HSPA9) and mitofusin-1 in the cerebellar cortex. Moreover, the numbers of Dendra-labeled mitochondria are significantly decreased in cerebellar cortex, confirming asymptomatic cerebellar mitochondrial biogenesis deficits. Functionally, complex I and II enzyme activities are significantly reduced in isolated mitochondria and tissue homogenates from asymptomatic KIKO cerebella. Structurally, levels of the complex I core subunit NUDFB8 and complex II subunits SDHA and SDHB are significantly lower than those in age-matched controls. These results demonstrate complex I and II deficiency in KIKO cerebellum, consistent with defects identified in FRDA patient tissues. Thus, our findings identify early cerebellar mitochondrial biogenesis deficits as a potential mediator of cerebellar dysfunction and ataxia, thereby providing a potential therapeutic target for early intervention of FRDA.
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Affiliation(s)
- Hong Lin
- Departments of Pediatrics and Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Jordi Magrane
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY 10065, USA
| | - Amy Rattelle
- Departments of Pediatrics and Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Anna Stepanova
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY 10065, USA
- Queen's University Belfast, School of Biological Sciences, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Alexander Galkin
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY 10065, USA
- Queen's University Belfast, School of Biological Sciences, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Elisia M Clark
- Departments of Pediatrics and Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yi Na Dong
- Departments of Pediatrics and Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Sarah M Halawani
- Departments of Pediatrics and Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - David R Lynch
- Departments of Pediatrics and Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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16
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Mitochondrial Function and Mitophagy in the Elderly: Effects of Exercise. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:2012798. [PMID: 28900532 PMCID: PMC5576425 DOI: 10.1155/2017/2012798] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 06/04/2017] [Accepted: 07/06/2017] [Indexed: 12/22/2022]
Abstract
Aging is a natural, multifactorial and multiorganic phenomenon wherein there are gradual physiological and pathological changes over time. Aging has been associated with a decrease of autophagy capacity and mitochondrial functions, such as biogenesis, dynamics, and mitophagy. These processes are essential for the maintenance of mitochondrial structural integrity and, therefore, for cell life, since mitochondrial dysfunction leads to an impairment of energy metabolism and increased production of reactive oxygen species, which consequently trigger mechanisms of cellular senescence and apoptotic cell death. Moreover, reduced mitochondrial function can contribute to age-associated disease phenotypes in model organisms and humans. Literature data show beneficial effects of exercise on the impairment of mitochondrial biogenesis and dynamics and on the decrease in the mitophagic capacity associated to aging. Thus, exercise could have effects on the major cell signaling pathways that are involved in the mitochondria quality and quantity control in the elderly. Although it is known that several exercise protocols are able to modify the activity and turnover of mitochondria, further studies are necessary in order to better identify the mechanisms of interaction between mitochondrial functions, aging, and physical activity, as well as to analyze possible factors influencing these processes.
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17
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Picca A, Lezza AMS. Regulation of mitochondrial biogenesis through TFAM-mitochondrial DNA interactions: Useful insights from aging and calorie restriction studies. Mitochondrion 2015; 25:67-75. [PMID: 26437364 DOI: 10.1016/j.mito.2015.10.001] [Citation(s) in RCA: 185] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 09/24/2015] [Accepted: 10/01/2015] [Indexed: 11/24/2022]
Abstract
Mitochondrial biogenesis is regulated to adapt mitochondrial population to cell energy demands. Mitochondrial transcription factor A (TFAM) performs several functions for mtDNA and interactions between TFAM and mtDNA participate to regulation of mitochondrial biogenesis. Such interactions are modulated through different mechanisms: regulation of TFAM expression and turnover, modulation of TFAM binding activity to mtDNA through post-translational modifications and differential affinity of TFAM, occurrence of TFAM sliding on mtDNA filaments and of cooperative binding among TFAM molecules, modulation of protein-protein interactions. The tissue-specific regulation of mitochondrial biogenesis in aging and calorie restriction (CR) highlights the relevance of modulation of TFAM-mtDNA interactions.
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Affiliation(s)
- Anna Picca
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Via Orabona, 4, 70125, Bari, Italy
| | - Angela Maria Serena Lezza
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Via Orabona, 4, 70125, Bari, Italy.
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18
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Moustafa IM, Uchida A, Wang Y, Yennawar N, Cameron CE. Structural models of mammalian mitochondrial transcription factor B2. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2015; 1849:987-1002. [PMID: 26066983 DOI: 10.1016/j.bbagrm.2015.05.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 05/22/2015] [Accepted: 05/25/2015] [Indexed: 11/26/2022]
Abstract
Mammalian mitochondrial DNA (mtDNA) encodes 13 core proteins of oxidative phosphorylation, 12S and 16S ribosomal RNAs, and 22 transfer RNAs. Mutations and deletions of mtDNA and/or nuclear genes encoding mitochondrial proteins have been implicated in a wide range of diseases. Thus, cell survival and health of the organism require some steady-state level of the mitochondrial genome and its expression. In mammalian systems, the mitochondrial transcription factor B2 (mtTFB2 or TFB2M) is indispensable for transcription initiation. TFB2M along with two other proteins, mitochondrial RNA polymerase (mtRNAP or POLRMT) and mitochondrial transcription factor A (mtTFA or TFAM), are key components of the core mitochondrial transcription apparatus. Structural information for POLRMT and TFAM from humans is available; however, there is no available structure for TFB2M. In the present study, three-dimensional structure of TFB2M from humans was modeled using a combination of homology modeling and small-angle X-ray scattering (SAXS). The TFB2M structural model adds substantively to our understanding of TFB2M function. An explanation for the low or absent RNA methyltransferase activity is provided. A putative nucleic acid-binding site is revealed. The amino and carboxy termini, while likely lacking defined secondary structure, appear to adopt compact, globular conformations, thus "capping" the ends of the protein. Finally, sites of interaction of TFB2M with other factors, protein and/or nucleic acid, are suggested by the identification of species-specific clusters on the surface of the protein.
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Affiliation(s)
- Ibrahim M Moustafa
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA.
| | - Akira Uchida
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Yao Wang
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Neela Yennawar
- Huck Institutes of Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
| | - Craig E Cameron
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA.
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19
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Colom B, Oliver J, Garcia-Palmer FJ. Sexual Dimorphism in the Alterations of Cardiac Muscle Mitochondrial Bioenergetics Associated to the Ageing Process. J Gerontol A Biol Sci Med Sci 2014; 70:1360-9. [PMID: 24682352 DOI: 10.1093/gerona/glu014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 01/16/2014] [Indexed: 12/11/2022] Open
Abstract
The incidence of cardiac disease is age and sex dependent, but the mechanisms governing these associations remain poorly understood. Mitochondria are the organelles in charge of producing energy for the cells, and their malfunction has been linked to cardiovascular disease and heart failure. Interestingly, heart mitochondrial content and functionality are also age and sex dependent. Here we investigated the combinatory effects of age and sex in mitochondrial bioenergetics that could help to understand their role on cardiac disease. Cardiac mitochondria from 6- and 24-month-old male and female Wistar rats were isolated, and the enzymatic activities of the oxidative-phosphorylative complexes I, III, and IV and ATPase, as well as the protein levels of complex IV, β-ATPase, and mitochondrial transcription factor A (TFAM), were measured. Furthermore, heart DNA content, citrate synthase activity, mitochondrial protein content, oxygen consumption, and H2O2 generation were also determined. Results showed a reduction in heart mitochondrial mass and functionality with age that correlated with increased H2O2 generation. Moreover, sex-dependent differences were found in several of these parameters. In particular, old females exhibited a significant loss of mitochondrial function and increased relative H2O2 production compared with their male counterparts. The results demonstrate a sex dimorphism in the age-associated defects on cardiac mitochondrial function.
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Affiliation(s)
- Bartomeu Colom
- Grup de Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Universitat de les Illes Balears, Palma de Mallorca, Spain. Present address: Centre for Microvascular Research, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK.
| | - Jordi Oliver
- Grup de Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Universitat de les Illes Balears, Palma de Mallorca, Spain. CIBERobn Fisiopatología Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, Palma de Mallorca, Spain
| | - Francisco J Garcia-Palmer
- Grup de Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Universitat de les Illes Balears, Palma de Mallorca, Spain. CIBERobn Fisiopatología Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, Palma de Mallorca, Spain
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20
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Picca A, Pesce V, Fracasso F, Joseph AM, Leeuwenburgh C, Lezza AMS. A comparison among the tissue-specific effects of aging and calorie restriction on TFAM amount and TFAM-binding activity to mtDNA in rat. Biochim Biophys Acta Gen Subj 2014; 1840:2184-91. [PMID: 24631828 DOI: 10.1016/j.bbagen.2014.03.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 03/03/2014] [Accepted: 03/05/2014] [Indexed: 01/30/2023]
Abstract
BACKGROUND Mitochondrial Transcription Factor A (TFAM) is regarded as a histone-like protein of mitochondrial DNA (mtDNA), performing multiple functions for this genome. Aging affects mitochondria in a tissue-specific manner and only calorie restriction (CR) is able to delay or prevent the onset of several age-related changes also in mitochondria. METHODS Samples of the frontal cortex and soleus skeletal muscle from 6- and 26-month-old ad libitum-fed and 26-month-old calorie-restricted rats and of the livers from 18- and 28-month-old ad libitum-fed and 28-month-old calorie-restricted rats were used to detect TFAM amount, TFAM-binding to mtDNA and mtDNA content. RESULTS We found an age-related increase in TFAM amount in the frontal cortex, not affected by CR, versus an age-related decrease in the soleus and liver, fully prevented by CR. The semi-quantitative analysis of in vivo binding of TFAM to specific mtDNA regions, by mtDNA immunoprecipitation assay and following PCR, showed a marked age-dependent decrease in TFAM-binding activity in the frontal cortex, partially prevented by CR. An age-related increase in TFAM-binding to mtDNA, fully prevented by CR, was found in the soleus and liver. MtDNA content presented a common age-related decrease, completely prevented by CR in the soleus and liver, but not in the frontal cortex. CONCLUSIONS The modulation of TFAM expression, TFAM-binding to mtDNA and mtDNA content with aging and CR showed a trend shared by the skeletal muscle and liver, but not by the frontal cortex counterpart. GENERAL SIGNIFICANCE Aging and CR appear to induce similar mitochondrial molecular mechanisms in the skeletal muscle and liver, different from those elicited in the frontal cortex.
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Affiliation(s)
- Anna Picca
- Department of Aging and Geriatric Research, Institute on Aging, Division of Biology of Aging, University of Florida, 2004 Mowry Rd, Gainesville, FL 32611, USA
| | - Vito Pesce
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Via Orabona, 4, 70125 Bari, Italy
| | - Flavio Fracasso
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Via Orabona, 4, 70125 Bari, Italy
| | - Anna-Maria Joseph
- Department of Aging and Geriatric Research, Institute on Aging, Division of Biology of Aging, University of Florida, 2004 Mowry Rd, Gainesville, FL 32611, USA
| | - Christiaan Leeuwenburgh
- Department of Aging and Geriatric Research, Institute on Aging, Division of Biology of Aging, University of Florida, 2004 Mowry Rd, Gainesville, FL 32611, USA
| | - Angela Maria Serena Lezza
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Via Orabona, 4, 70125 Bari, Italy.
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21
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Liu L, Nam M, Fan W, Akie TE, Hoaglin DC, Gao G, Keaney JF, Cooper MP. Nutrient sensing by the mitochondrial transcription machinery dictates oxidative phosphorylation. J Clin Invest 2014; 124:768-84. [PMID: 24430182 PMCID: PMC4381729 DOI: 10.1172/jci69413] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Accepted: 11/07/2013] [Indexed: 11/17/2022] Open
Abstract
Sirtuin 3 (SIRT3), an important regulator of energy metabolism and lipid oxidation, is induced in fasted liver mitochondria and implicated in metabolic syndrome. In fasted liver, SIRT3-mediated increases in substrate flux depend on oxidative phosphorylation (OXPHOS), but precisely how OXPHOS meets the challenge of increased substrate oxidation in fasted liver remains unclear. Here, we show that liver mitochondria in fasting mice adapt to the demand of increased substrate oxidation by increasing their OXPHOS efficiency. In response to cAMP signaling, SIRT3 deacetylated and activated leucine-rich protein 130 (LRP130; official symbol, LRPPRC), promoting a mitochondrial transcriptional program that enhanced hepatic OXPHOS. Using mass spectrometry, we identified SIRT3-regulated lysine residues in LRP130 that generated a lysine-to-arginine (KR) mutant of LRP130 that mimics deacetylated protein. Compared with wild-type LRP130 protein, expression of the KR mutant increased mitochondrial transcription and OXPHOS in vitro. Indeed, even when SIRT3 activity was abolished, activation of mitochondrial transcription and OXPHOS by the KR mutant remained robust, further highlighting the contribution of LRP130 deacetylation to increased OXPHOS in fasted liver. These data establish a link between nutrient sensing and mitochondrial transcription that regulates OXPHOS in fasted liver and may explain how fasted liver adapts to increased substrate oxidation.
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Affiliation(s)
- Lijun Liu
- Division of Cardiovascular Medicine, Department of Medicine,
Division of Biostatistics and Health Services Research, Department of Quantitative Health Sciences, and
Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Minwoo Nam
- Division of Cardiovascular Medicine, Department of Medicine,
Division of Biostatistics and Health Services Research, Department of Quantitative Health Sciences, and
Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Wei Fan
- Division of Cardiovascular Medicine, Department of Medicine,
Division of Biostatistics and Health Services Research, Department of Quantitative Health Sciences, and
Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Thomas E. Akie
- Division of Cardiovascular Medicine, Department of Medicine,
Division of Biostatistics and Health Services Research, Department of Quantitative Health Sciences, and
Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - David C. Hoaglin
- Division of Cardiovascular Medicine, Department of Medicine,
Division of Biostatistics and Health Services Research, Department of Quantitative Health Sciences, and
Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Guangping Gao
- Division of Cardiovascular Medicine, Department of Medicine,
Division of Biostatistics and Health Services Research, Department of Quantitative Health Sciences, and
Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - John F. Keaney
- Division of Cardiovascular Medicine, Department of Medicine,
Division of Biostatistics and Health Services Research, Department of Quantitative Health Sciences, and
Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Marcus P. Cooper
- Division of Cardiovascular Medicine, Department of Medicine,
Division of Biostatistics and Health Services Research, Department of Quantitative Health Sciences, and
Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
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22
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Yakubovskaya E, Guja KE, Eng ET, Choi WS, Mejia E, Beglov D, Lukin M, Kozakov D, Garcia-Diaz M. Organization of the human mitochondrial transcription initiation complex. Nucleic Acids Res 2014; 42:4100-12. [PMID: 24413562 PMCID: PMC3973321 DOI: 10.1093/nar/gkt1360] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Initiation of transcription in human mitochondria involves two factors, TFAM and TFB2M, in addition to the mitochondrial RNA polymerase, POLRMT. We have investigated the organization of the human mitochondrial transcription initiation complex on the light-strand promoter (LSP) through solution X-ray scattering, electron microscopy (EM) and biochemical studies. Our EM results demonstrate a compact organization of the initiation complex, suggesting that protein–protein interactions might help mediate initiation. We demonstrate that, in the absence of DNA, only POLRMT and TFAM form a stable interaction, albeit one with low affinity. This is consistent with the expected transient nature of the interactions necessary for initiation and implies that the promoter DNA acts as a scaffold that enables formation of the full initiation complex. Docking of known crystal structures into our EM maps results in a model for transcriptional initiation that strongly correlates with new and existing biochemical observations. Our results reveal the organization of TFAM, POLRMT and TFB2M around the LSP and represent the first structural characterization of the entire mitochondrial transcriptional initiation complex.
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Affiliation(s)
- Elena Yakubovskaya
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, Cryo-Electron Microscopy Facility, New York Structural Biology Center, New York, NY 10027 and Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
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23
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Picca A, Fracasso F, Pesce V, Cantatore P, Joseph AM, Leeuwenburgh C, Gadaleta MN, Lezza AMS. Age- and calorie restriction-related changes in rat brain mitochondrial DNA and TFAM binding. AGE (DORDRECHT, NETHERLANDS) 2013; 35:1607-20. [PMID: 22945739 PMCID: PMC3776104 DOI: 10.1007/s11357-012-9465-z] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Accepted: 07/27/2012] [Indexed: 06/01/2023]
Abstract
Aging markedly affects mitochondrial biogenesis and functions particularly in tissues highly dependent on the organelle's bioenergetics capability such as the brain's frontal cortex. Calorie restriction (CR) diet is, so far, the only intervention able to delay or prevent the onset of several age-related alterations in different organisms. We determined the contents of mitochondrial transcription factor A (TFAM), mitochondrial DNA (mtDNA), and the 4.8-kb mtDNA deletion in the frontal cortex from young (6-month-old) and aged (26-month-old), ad libitum-fed (AL) and calorie-restricted (CR), rats. We found a 70 % increase in TFAM amount, a 25 % loss in mtDNA content, and a 35 % increase in the 4.8-kb deletion content in the aged AL animals with respect to the young rats. TFAM-specific binding to six mtDNA regions was analyzed by mtDNA immunoprecipitation and semiquantitative polymerase chain reaction (PCR), showing a marked age-related decrease. Quantitative real-time PCR at two subregions involved in mtDNA replication demonstrated, in aged AL rats, a remarkable decrease (60-70 %) of TFAM-bound mtDNA. The decreased TFAM binding is a novel finding that may explain the mtDNA loss in spite of the compensatory TFAM increased amount. In aged CR rats, TFAM amount increased and mtDNA content decreased with respect to young rats' values, but the extent of the changes was smaller than in aged AL rats. Attenuation of the age-related effects due to the diet in the CR animals was further evidenced by the unchanged content of the 4.8-kb deletion with respect to that of young animals and by the partial prevention of the age-related decrease in TFAM binding to mtDNA.
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Affiliation(s)
- Anna Picca
- />Department of Biosciences, Biotechnologies and Pharmacological Sciences, University of Bari, Via Orabona, 4, 70125 Bari, Italy
| | - Flavio Fracasso
- />Department of Biosciences, Biotechnologies and Pharmacological Sciences, University of Bari, Via Orabona, 4, 70125 Bari, Italy
| | - Vito Pesce
- />Department of Biosciences, Biotechnologies and Pharmacological Sciences, University of Bari, Via Orabona, 4, 70125 Bari, Italy
| | - Palmiro Cantatore
- />Department of Biosciences, Biotechnologies and Pharmacological Sciences, University of Bari, Via Orabona, 4, 70125 Bari, Italy
- />Institute of Biomembranes and Bioenergetics, CNR-National Research Council of Italy, Via Amendola, 165/A, 70126 Bari, Italy
| | - Anna-Maria Joseph
- />Division of Biology of Aging, Department of Aging and Geriatric Research, Institute on Aging, University of Florida, Gainesville, FL USA
| | - Christiaan Leeuwenburgh
- />Division of Biology of Aging, Department of Aging and Geriatric Research, Institute on Aging, University of Florida, Gainesville, FL USA
| | - Maria Nicola Gadaleta
- />Department of Biosciences, Biotechnologies and Pharmacological Sciences, University of Bari, Via Orabona, 4, 70125 Bari, Italy
- />Institute of Biomembranes and Bioenergetics, CNR-National Research Council of Italy, Via Amendola, 165/A, 70126 Bari, Italy
| | - Angela Maria Serena Lezza
- />Department of Biosciences, Biotechnologies and Pharmacological Sciences, University of Bari, Via Orabona, 4, 70125 Bari, Italy
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Picca A, Pesce V, Fracasso F, Joseph AM, Leeuwenburgh C, Lezza AMS. Aging and calorie restriction oppositely affect mitochondrial biogenesis through TFAM binding at both origins of mitochondrial DNA replication in rat liver. PLoS One 2013; 8:e74644. [PMID: 24058615 PMCID: PMC3772924 DOI: 10.1371/journal.pone.0074644] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 08/02/2013] [Indexed: 11/19/2022] Open
Abstract
Aging affects mitochondria in a tissue-specific manner. Calorie restriction (CR) is, so far, the only intervention able to delay or prevent the onset of several age-related changes also in mitochondria. Using livers from middle age (18-month-old), 28-month-old and 32-month-old ad libitum-fed and 28-month-old calorie-restricted rats we found an age-related decrease in mitochondrial DNA (mtDNA) content and mitochondrial transcription factor A (TFAM) amount, fully prevented by CR. We revealed also an age-related decrease, completely prevented by CR, for the proteins PGC-1α NRF-1 and cytochrome c oxidase subunit IV, supporting the efficiency of CR to forestall the age-related decrease in mitochondrial biogenesis. Furthermore, CR counteracted the age-related increase in oxidative damage to proteins, represented by the increased amount of oxidized peroxiredoxins (PRX-SO3) in the ad libitum-fed animals. An unexpected age-related decrease in the mitochondrial proteins peroxiredoxin III (Prx III) and superoxide dismutase 2 (SOD2), usually induced by increased ROS and involved in mitochondrial biogenesis, suggested a prevailing relevance of the age-reduced mitochondrial biogenesis above the induction by ROS in the regulation of expression of these genes with aging. The partial prevention of the decrease in Prx III and SOD2 proteins by CR also supported the preservation of mitochondrial biogenesis in the anti-aging action of CR. To investigate further the age- and CR-related effects on mitochondrial biogenesis we analyzed the in vivo binding of TFAM to specific mtDNA regions and demonstrated a marked increase in the TFAM-bound amounts of mtDNA at both origins of replication with aging, fully prevented by CR. A novel, positive correlation between the paired amounts of TFAM-bound mtDNA at these sub-regions was found in the joined middle age ad libitum-fed and 28-month-old calorie-restricted groups, but not in the 28-month-old ad libitum-fed counterpart suggesting a quite different modulation of TFAM binding at both origins of replication in aging and CR.
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Affiliation(s)
- Anna Picca
- Department of Aging and Geriatric Research, Institute on Aging, Division of Biology of Aging, University of Florida, Gainesville, United States of America
| | - Vito Pesce
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Flavio Fracasso
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Anna-Maria Joseph
- Department of Aging and Geriatric Research, Institute on Aging, Division of Biology of Aging, University of Florida, Gainesville, United States of America
| | - Christiaan Leeuwenburgh
- Department of Aging and Geriatric Research, Institute on Aging, Division of Biology of Aging, University of Florida, Gainesville, United States of America
| | - Angela M. S. Lezza
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
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25
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Dominy JE, Puigserver P. Mitochondrial biogenesis through activation of nuclear signaling proteins. Cold Spring Harb Perspect Biol 2013; 5:5/7/a015008. [PMID: 23818499 DOI: 10.1101/cshperspect.a015008] [Citation(s) in RCA: 175] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The dynamics of mitochondrial biogenesis and function is a complex interplay of cellular and molecular processes that ultimately shape bioenergetics capacity. Mitochondrial mass, by itself, represents the net balance between rates of biogenesis and degradation. Mitochondrial biogenesis is dependent on different signaling cascades and transcriptional complexes that promote the formation and assembly of mitochondria--a process that is heavily dependent on timely and coordinated transcriptional control of genes encoding for mitochondrial proteins. In this article, we discuss the major signals and transcriptional complexes, programming mitochondrial biogenesis, and bioenergetic activity. This regulatory network represents a new therapeutic window into the treatment of the wide spectrum of mitochondrial and neurodegenerative diseases characterized by dysregulation of mitochondrial dynamics and bioenergetic deficiencies.
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Affiliation(s)
- John E Dominy
- Department of Cancer Biology, Dana-Farber Cancer Institute and Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02215, USA
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26
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Dual control of mitochondrial biogenesis by sirtuin 1 and sirtuin 3. Mitochondrion 2013; 13:755-61. [PMID: 23583953 DOI: 10.1016/j.mito.2013.04.002] [Citation(s) in RCA: 171] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 03/25/2013] [Accepted: 04/04/2013] [Indexed: 12/31/2022]
Abstract
In this review, we discuss the dual control of mitochondrial biogenesis and energy metabolism by silent information regulator-1 and -3 (SIRT1 and SIRT3). SIRT1 activates the peroxisome proliferator activated receptor γ co-activator 1α (PGC-1α)-mediated transcription of nuclear and mitochondrial genes encoding for proteins promoting mitochondria proliferation, oxidative phosphorylation and energy production, whereas SIRT3 directly acts as an activator of proteins important for oxidative phosphorylation, tricarboxylic acid (TCA) cycle and fatty-acid oxidation and indirectly of PGC-1α and AMP-activated protein kinase (AMPK). The complex network involves different cellular compartments, transcriptional activation, post-translational modification and a plethora of secondary effectors. Overall, the mode of interaction between both sirtuin family members may be considered as a prominent case of molecular job-sharing.
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27
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Campbell CT, Kolesar JE, Kaufman BA. Mitochondrial transcription factor A regulates mitochondrial transcription initiation, DNA packaging, and genome copy number. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2012; 1819:921-9. [DOI: 10.1016/j.bbagrm.2012.03.002] [Citation(s) in RCA: 236] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 03/08/2012] [Accepted: 03/15/2012] [Indexed: 10/28/2022]
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28
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Transcription from the second heavy-strand promoter of human mtDNA is repressed by transcription factor A in vitro. Proc Natl Acad Sci U S A 2012; 109:6513-8. [PMID: 22493245 DOI: 10.1073/pnas.1118710109] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cell-based studies support the existence of two promoters on the heavy strand of mtDNA: heavy-strand promoter 1 (HSP1) and HSP2. However, transcription from HSP2 has been reported only once in a cell-free system, and never when recombinant proteins have been used. Here, we document transcription from HSP2 using an in vitro system of defined composition. An oligonucleotide template representing positions 596-685 of mtDNA was sufficient to observe transcription by the human mtRNA polymerase (POLRMT) that was absolutely dependent on mitochondrial transcription factor B2 (TFB2M). POLRMT/TFB2M-dependent transcription was inhibited by concentrations of mitochondrial transcription factor A (TFAM) stoichiometric with the transcription template, a condition that activates transcription from the light-strand promoter (LSP) in vitro. Domains of TFAM required for LSP activation were also required for HSP2 repression, whereas other mtDNA binding proteins failed to alter transcriptional output. Binding sites for TFAM were located on both sides of the start site of transcription from HSP2, suggesting that TFAM binding interferes with POLRMT and/or TFB2M binding. Consistent with a competitive binding model for TFAM repression of HSP2, the impact of TFAM concentration on HSP2 transcription was diminished by elevating the POLRMT and TFB2M concentrations. In the context of our previous studies of LSP and HSP1, it is now clear that three promoters exist in human mtDNA. Each promoter has a unique requirement for and/or response to the level of TFAM present, thus implying far greater complexity in the regulation of mammalian mitochondrial transcription than recognized to date.
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29
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Guevara R, Gianotti M, Roca P, Oliver J. Age and sex-related changes in rat brain mitochondrial function. Cell Physiol Biochem 2011; 27:201-6. [PMID: 21471708 DOI: 10.1159/000327945] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/27/2011] [Indexed: 11/19/2022] Open
Abstract
Aging is responsible for the decline in the function of mitochondria and their increase in size and number--adaptive mechanism to restore mitochondrial function. Estrogens increase mitochondrial function, especially in female rats. The aim of this study was to determine the age-related changes in rat brain mitochondrial function focusing on sex differences. Cellular and mitochondrial protein and DNA content, mitochondrial oxidative and phosphorylative function in male and female rat brain from four different age groups (6, 12, 18 and 24 months old) were analyzed. Mitochondria protein/DNA content decreased with aging shifting toward lesser mitochondrial functional capacity and the mitochondria number increased. A sex dimorphism was determined, with female rat brain showing mitochondria with greater functional capacity than males. These sex differences gradually increased during aging.
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Affiliation(s)
- Rocío Guevara
- Grupo de Metabolismo Energético y Nutrición, Departamento de Biología Fundamental y Ciencias de la Salud, Instituto Universitario de Investigación en Ciencias de la Salud, Universitat de les Illes Balears, Palma de Mallorca, Spain.
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30
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Thomas RR, Khan SM, Portell FR, Smigrodzki RM, Bennett JP. Recombinant human mitochondrial transcription factor A stimulates mitochondrial biogenesis and ATP synthesis, improves motor function after MPTP, reduces oxidative stress and increases survival after endotoxin. Mitochondrion 2010; 11:108-18. [PMID: 20727424 DOI: 10.1016/j.mito.2010.08.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Revised: 07/15/2010] [Accepted: 08/06/2010] [Indexed: 11/17/2022]
Abstract
Recombinant human mitochondrial transcription factor A protein (rhTFAM) was evaluated for its acute effects on cultured cells and chronic effects in mice. Fibroblasts incubated with rhTFAM acutely increased respiration in a chloramphenicol-sensitive manner. SH-SY5Y cells showed rhTFAM concentration-dependent reduction of methylpyridinium (MPP(+))-induced oxidative stress and increases in lowered ATP levels and viability. Mice treated with weekly i.v. rhTFAM showed increased mitochondrial gene copy number, complex I protein levels and ATP production rates; oxidative damage to proteins was decreased ~50%. rhTFAM treatment improved motor recovery rate after treatment with MPTP and dose-dependently improved survival in the lipopolysaccharide model of endotoxin sepsis.
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Affiliation(s)
- Ravindar R Thomas
- Morris Udall Parkinson's Disease Research Center of Excellence, University of Virginia, Charlottesville, VA, United States
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31
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Aquilano K, Vigilanza P, Baldelli S, Pagliei B, Rotilio G, Ciriolo MR. Peroxisome proliferator-activated receptor gamma co-activator 1alpha (PGC-1alpha) and sirtuin 1 (SIRT1) reside in mitochondria: possible direct function in mitochondrial biogenesis. J Biol Chem 2010; 285:21590-9. [PMID: 20448046 DOI: 10.1074/jbc.m109.070169] [Citation(s) in RCA: 265] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The transcriptional co-activator PGC-1alpha and the NAD(+)-dependent deacetylase SIRT1 are considered important inducers of mitochondrial biogenesis because in the nucleus they regulate transcription of nucleus-encoded mitochondrial genes. We demonstrate that PGC-1alpha and SIRT1 are also present inside mitochondria and are in close proximity to mtDNA. They interact with mitochondrial transcription factor A (TFAM) as assessed by confocal microscopy analysis and by blue native-PAGE. Nucleoid purification allowed us to identify SIRT1 and PGC-1alpha as proteins associated with native and cross-linked nucleoids, respectively. After mtDNA immunoprecipitation analysis, carried out on mitochondrial extracts, we found that PGC-1alpha is present on the same D-loop region recognized by TFAM. Finally, by oligonucleotide pulldown assay, we found PGC-1alpha and SIRT1 associated with the TFAM consensus sequence (human mitochondrial transcription factor-binding site H). The results obtained suggest that in mitochondria PGC-1alpha and SIRT1 may function as their nuclear counterparts and represent the genuine factors mediating the cross-talk between nuclear and mitochondrial genome. Finally, this work adds new knowledge on the function of SIRT1 and PGC-1alpha and highlights the direct involvement of such proteins in regulation of mitochondrial biogenesis.
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Affiliation(s)
- Katia Aquilano
- Department of Biology, University of Rome Tor Vergata, 00133 Rome, Italy
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32
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Yang Y, Cimen H, Han MJ, Shi T, Deng JH, Koc H, Palacios OM, Montier L, Bai Y, Tong Q, Koc EC. NAD+-dependent deacetylase SIRT3 regulates mitochondrial protein synthesis by deacetylation of the ribosomal protein MRPL10. J Biol Chem 2010; 285:7417-7429. [PMID: 20042612 PMCID: PMC2844190 DOI: 10.1074/jbc.m109.053421] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Revised: 12/03/2009] [Indexed: 10/02/2023] Open
Abstract
A member of the sirtuin family of NAD(+)-dependent deacetylases, SIRT3, is located in mammalian mitochondria and is important for regulation of mitochondrial metabolism, cell survival, and longevity. In this study, MRPL10 (mitochondrial ribosomal protein L10) was identified as the major acetylated protein in the mitochondrial ribosome. Ribosome-associated SIRT3 was found to be responsible for deacetylation of MRPL10 in an NAD(+)-dependent manner. We mapped the acetylated Lys residues by tandem mass spectrometry and determined the role of these residues in acetylation of MRPL10 by site-directed mutagenesis. Furthermore, we observed that the increased acetylation of MRPL10 led to an increase in translational activity of mitochondrial ribosomes in Sirt3(-/-) mice. In a similar manner, ectopic expression and knockdown of SIRT3 in C2C12 cells resulted in the suppression and enhancement of mitochondrial protein synthesis, respectively. Our findings constitute the first evidence for the regulation of mitochondrial protein synthesis by the reversible acetylation of the mitochondrial ribosome and characterize MRPL10 as a novel substrate of the NAD(+)-dependent deacetylase, SIRT3.
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Affiliation(s)
- Yongjie Yang
- From the Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas 77030
| | - Huseyin Cimen
- the Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, and
| | - Min-Joon Han
- the Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, and
| | - Tong Shi
- From the Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas 77030
| | - Jian-Hong Deng
- the Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - Hasan Koc
- the Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, and
| | - Orsolya M. Palacios
- From the Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas 77030
| | - Laura Montier
- the Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - Yidong Bai
- the Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - Qiang Tong
- From the Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas 77030
| | - Emine C. Koc
- the Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, and
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Cimen H, Han MJ, Yang Y, Tong Q, Koc H, Koc EC. Regulation of succinate dehydrogenase activity by SIRT3 in mammalian mitochondria. Biochemistry 2010; 49:304-11. [PMID: 20000467 DOI: 10.1021/bi901627u] [Citation(s) in RCA: 341] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A member of the sirtuin family of NAD(+)-dependent deacetylases, SIRT3, is identified as one of the major mitochondrial deacetylases located in mammalian mitochondria responsible for deacetylation of several metabolic enzymes and components of oxidative phosphorylation. Regulation of protein deacetylation by SIRT3 is important for mitochondrial metabolism, cell survival, and longevity. In this study, we identified one of the Complex II subunits, succinate dehydrogenase flavoprotein (SdhA) subunit, as a novel SIRT3 substrate in SIRT3 knockout mice. Several acetylated Lys residues were mapped by tandem mass spectrometry, and we determined the role of acetylation in Complex II activity in SIRT3 knockout mice. In agreement with SIRT3-dependent activation of Complex I, we observed that deacetylation of the SdhA subunit increased the Complex II activity in wild-type mice. In addition, we treated K562 cell lines with nicotinamide and kaempferol to inhibit deacetylase activity of SIRT3 and stimulate SIRT3 expression, respectively. Stimulation of SIRT3 expression decreased the level of acetylation of the SdhA subunit and increased Complex II activity in kaempherol-treated cells compared to control and nicotinamide-treated cells. Evaluation of acetylated residues in the SdhA crystal structure from porcine and chicken suggests that acetylation of the hydrophilic surface of SdhA may control the entry of the substrate into the active site of the protein and regulate the enzyme activity. Our findings constitute the first evidence of the regulation of Complex II activity by the reversible acetylation of the SdhA subunit as a novel substrate of the NAD(+)-dependent deacetylase, SIRT3.
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Affiliation(s)
- Huseyin Cimen
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
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Rosca MG, Lemieux H, Hoppel CL. Mitochondria in the elderly: Is acetylcarnitine a rejuvenator? Adv Drug Deliv Rev 2009; 61:1332-1342. [PMID: 19720100 DOI: 10.1016/j.addr.2009.06.009] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2009] [Accepted: 06/01/2009] [Indexed: 12/21/2022]
Abstract
Endogenous acetylcarnitine is an indicator of acetyl-CoA synthesized by multiple metabolic pathways involving carbohydrates, amino acids, fatty acids, sterols, and ketone bodies, and utilized mainly by the tricarboxylic acid cycle. Acetylcarnitine supplementation has beneficial effects in elderly animals and humans, including restoration of mitochondrial content and function. These effects appear to be dose-dependent and occur even after short-term therapy. In order to set the stage for understanding the mechanism of action of acetylcarnitine, we review the metabolism and role of this compound. We suggest that acetylation of mitochondrial proteins leads to a specific increase in mitochondrial gene expression and mitochondrial protein synthesis. In the aged rat heart, this effect is translated to increased cytochrome b content, restoration of complex III activity, and oxidative phosphorylation, resulting in amelioration of the age-related mitochondrial defect.
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Affiliation(s)
- Mariana G Rosca
- Center for Mitochondrial Diseases and Departments of Medicine and Pharmacology, Case Western Reserve University, Cleveland, Ohio
| | - Hélène Lemieux
- Center for Mitochondrial Diseases and Departments of Medicine and Pharmacology, Case Western Reserve University, Cleveland, Ohio
| | - Charles L Hoppel
- Center for Mitochondrial Diseases and Departments of Medicine and Pharmacology, Case Western Reserve University, Cleveland, Ohio
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Lu Z, Scott I, Webster BR, Sack MN. The emerging characterization of lysine residue deacetylation on the modulation of mitochondrial function and cardiovascular biology. Circ Res 2009; 105:830-41. [PMID: 19850949 DOI: 10.1161/circresaha.109.204974] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
There is emerging recognition of a novel fuel and redox sensing regulatory program that controls cellular adaptation via nonhistone protein lysine residue acetyl posttranslation modifications. This program functions in tissues with high energy demand and oxidative capacity and is highly enriched in the heart. Deacetylation is regulated by NAD(+)-dependent activation of the sirtuin family of proteins, whereas acetyltransferase modifications are controlled by less clearly delineated acetyltransferases. Subcellular localization specific protein targets of lysine-acetyl modification have been identified in the nucleus, cytoplasm, and mitochondria. Despite distinct subcellular localizations, these modifications appear, in large part, to modify mitochondrial properties including respiration, energy production, apoptosis, and antioxidant defenses. These mitochondrial regulatory programs are important in cardiovascular biology, although how protein acetyl modifications effects cardiovascular pathophysiology has not been extensively explored. This review will introduce the role of nonhistone protein lysine residue acetyl modifications, discuss their regulation and biochemistry and present the direct and indirect data implicating their involvement in the heart and vasculature.
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Affiliation(s)
- Zhongping Lu
- Translational Medicine Branch, National Heart, Lung, and Blood Institute, Bethesda, MD, USA
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36
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McInerny SC, Brown AL, Smith DW. Region-specific changes in mitochondrial D-loop in aged rat CNS. Mech Ageing Dev 2009; 130:343-9. [PMID: 19428453 DOI: 10.1016/j.mad.2009.01.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Revised: 12/22/2008] [Accepted: 01/25/2009] [Indexed: 01/06/2023]
Abstract
Impaired mitochondrial oxidative phosphorylation (OXPHOS) is considered a cause of aging. A reduction in mitochondrial DNA (mtDNA) replication and/or transcription may contribute to this OXPHOS diminution. Impairments in the displacement (D) loop, or non-coding, region of the mitochondrial genome, or accumulation of mtDNA mutations, may affect mtDNA replication and transcription. We determined the effects of age on the D-loop and on mtDNA deletion mutations in the spinal cord, medulla, midbrain, cerebellum, striatum, and cerebral cortex of Fischer 344 rats. D-loop, 7S DNA levels were reduced by 3-fold in striatum, 2.5-fold in cortex, and 2-fold in the spinal cord of older animals. We did not detect a population of mtDNA affected by the most prevalent known (ND4-containing) deletions, indicating they do not comprise a significant portion of total mtDNA. However, we detected an age-related and region-specific increase in the common deletion, which comprised 0.0003-0.0007% of total mtDNA. Mitochondrial genome copy number varied between regions, in addition to an overall 18% decrease with age across the whole brain. These results suggest the age-related decline in OXPHOS may be related to a reduction in D-loop function.
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Affiliation(s)
- Simone C McInerny
- Discipline of Anatomy, School of Biomedical Sciences, Faculty of Health and The Center for Brain and Mental Health Research, University of Newcastle, Callaghan, NSW 2308, Australia
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Kienhöfer J, Häussler DJF, Ruckelshausen F, Muessig E, Weber K, Pimentel D, Ullrich V, Bürkle A, Bachschmid MM. Association of mitochondrial antioxidant enzymes with mitochondrial DNA as integral nucleoid constituents. FASEB J 2009; 23:2034-44. [PMID: 19228881 DOI: 10.1096/fj.08-113571] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Mitochondrial DNA (mtDNA) is organized in protein-DNA macrocomplexes called nucleoids. Average nucleoids contain 2-8 mtDNA molecules, which are organized by the histone-like mitochondrial transcription factor A. Besides well-characterized constituents, such as single-stranded binding protein or polymerase gamma (Pol gamma), various other proteins with ill-defined functions have been identified. We report for the first time that mammalian nucleoids contain essential enzymes of an integral antioxidant system. Intact nucleoids were isolated with sucrose density gradients from rat and bovine heart as well as human Jurkat cells. Manganese superoxide dismutase (SOD2) was detected by Western blot in the nucleoid fractions. DNA, mitochondrial glutathione peroxidase (GPx1), and Pol gamma were coimmunoprecipitated with SOD2 from nucleoid fractions, which suggests that an antioxidant system composed of SOD2 and GPx1 are integral constituents of nucleoids. Interestingly, in cultured bovine endothelial cells the association of SOD2 with mtDNA was absent. Using a sandwich filter-binding assay, direct association of SOD2 by salt-sensitive ionic forces with a chemically synthesized mtDNA fragment was demonstrated. Increasing salt concentrations during nucleoid isolation on sucrose density gradients disrupted the association of SOD2 with mitochondrial nucleoids. Our biochemical data reveal that nucleoids contain an integral antioxidant system that may protect mtDNA from superoxide-induced oxidative damage.
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Valle A, Guevara R, García-Palmer FJ, Roca P, Oliver J. Caloric restriction retards the age-related decline in mitochondrial function of brown adipose tissue. Rejuvenation Res 2008; 11:597-604. [PMID: 18593277 DOI: 10.1089/rej.2007.0626] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Caloric restriction (CR) has been shown to prevent the age-associated loss of mitochondrial function and biogenesis in several tissues such as liver, heart, and skeletal muscle. However, little is known about the effects of CR on a tissue in which the mitochondria have no adenosine triphosphate (ATP)-producing purpose but show a high degree of uncoupling, namely brown adipose tissue (BAT). Hence, the aim of the present study was to analyze the effect of long-term CR on BAT mitochondrial function and biogenesis. BAT mitochondria obtained from 24-month-old male and female rats previously subjected to 40% CR for 12 months were compared with mitochondria from old (24 months) and young (6 months) ad libitum fed rats. Old restricted rats compared to old ad libitum fed ones showed a reduction in BAT size with respect to fat content and adipocyte number. Mitochondrial DNA content in BAT increased with age and even more so in restricted rats, indicating a summative effect of age and CR on mitochondrial proliferation. CR induced resistance to lose total and mitochondrial protein, COX activity, and uncoupling capacity with advancing age, in relation with a lower decrease of mitochondrial transcription factor A (TFAM). In summary, our results demonstrate CR prevents the age-associated decline in mitochondrial function in BAT, probably in relation with a lower impairment of mitochondrial biogenesis.
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Affiliation(s)
- Adamo Valle
- Grup de Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Universitat de les Illes Balears, Palma de Mallorca, Ciber Fisiopatología Obesidad y Nutrición (CB06/03) Instituto Salud Carlos III, Spain
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Pastukh V, Shokolenko I, Wang B, Wilson G, Alexeyev M. Human mitochondrial transcription factor A possesses multiple subcellular targeting signals. FEBS J 2007; 274:6488-99. [PMID: 18028422 DOI: 10.1111/j.1742-4658.2007.06167.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The mitochondrial transcription factor A (TFAM) is a member of a high-mobility group (HMG) family represented mostly by nuclear proteins. Although nuclear localization of TFAM has been demonstrated in some tumors and after treatment of tumor cells with anticancer drugs, the significance of these observations has not been fully elucidated. Here we report that both TFAM overexpression and impairment of its mitochondrial targeting can result in nuclear accumulation of the protein. Both M1 and M7 methionines of human TFAM (hTFAM) can be used for translation initiation with almost equal efficiency resulting in two polypeptides. The shorter polypeptide, however, is not located in the nucleus, despite truncation in the mitochondrial targeting sequence, and both isoforms are targeted to mitochondria with similar efficiency. We further demonstrate that nuclear TFAM confers significant cytoprotection against the chemotherapeutic drugs etoposide, camptothecin, and cisplatin. Three regions of hTFAM [HMG-like domain 1 (HMG1) and HMG-like domain 2 (HMG2), as well as the tail region] can effect nuclear accumulation of enhanced green fluorescent protein (EGFP) fusions. The HMG1 domain contains a bipartite nuclear localization sequence whose identity is supported by site-directed mutagenesis. However, this bipartite nuclear localization sequence is weak, and both N-terminal and C-terminal flanking sequences enhance the nuclear targeting of EGFP. Finally, several mutations in the HMG1 domain increased the mitochondrial targeting of the EGFP fusions, suggesting that the mitochondrial targeting sequence of hTFAM may extend beyond the cleavable presequence.
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Affiliation(s)
- Viktoriya Pastukh
- Department of Cell Biology and Neuroscience, University of South Alabama, Mobile, AL 36688, USA
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40
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Abstract
HYPOTHESIS Damage to heart mitochondrial structure and function occur with aging, and in heart failure (HF). However, the extent of mitochondrial dysfunction, the expression of mitochondrial and nuclear genes, and their cross-talk is not known. OBSERVATIONS Several observations have suggested that somatic mutations in mitochondrial DNA (mtDNA), induced by reactive oxygen species (ROS), appear to be the primary cause of energy decline, and that the generation of ROS is mainly the product of the mitochondrial respiratory chain. The free radical theory of aging, that could also be applied to HF, and in particular the targeting of mtDNA is supported by a plurality of observations from both animal and clinical studies showing decreased mitochondrial function, increased ROS levels and mtDNA mutations in the aging heart. DISCUSSION Aging and HF with their increased ROS-induced defects in mtDNA, including base modifications and frequency of mtDNA deletions, might be expected to cause increased errors or mutations in mtDNA-encoded enzyme subunits, resulting in impaired oxidative phosphorylation and defective electron transport chain (ETC) activity which in turn creates more ROS. These events in both the aging and failing heart involve substantial nuclear-mitochondrial interaction, which is further illustrated in the progression of myocardial apoptosis. In this review the cross-talk between the nucleus and the mitochondrial organelle will be examined based on a number of animal and clinical studies, including our own.
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Affiliation(s)
- José Marín-García
- The Molecular Cardiology and Neuromuscular Institute, Highland Park, NJ 08904, USA.
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Passos JF, von Zglinicki T, Kirkwood TBL. Mitochondria and ageing: winning and losing in the numbers game. Bioessays 2007; 29:908-17. [PMID: 17688237 DOI: 10.1002/bies.20634] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Mitochondrial dysfunction has long been considered a key mechanism in the ageing process but surprisingly little attention has been paid to the impact of mitochondrial number or density within cells. Recent reports suggest a positive association between mitochondrial density, energy homeostasis and longevity. However, mitochondrial number also determines the number of sites generating reactive oxygen species (ROS) and we suggest that the links between mitochondrial density and ageing are more complex, potentially acting in both directions. The idea that increased density, especially when combined with mitochondrial dysfunction, might accelerate ageing is supported by a negative correlation between mitochondrial density and maximum longevity in an interspecies comparison in mammals, and by evidence for an intimate interconnection between cellular ROS levels, mitochondrial density and cellular ageing. Recent data suggest that retrograde response, which activates mitochondrial biogenesis, accompanies cellular ageing processes. We hypothesise that increased mitochondrial biogenesis, and possibly also impaired degradation and segregation of mitochondria, if occurring as adaptation to pre-existing mitochondrial dysfunction, might aggravate ROS production and thus actively contribute to ageing.
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Affiliation(s)
- João F Passos
- Centre for Integrated Systems Biology of Ageing and Nutrition, Henry Wellcome Laboratory for Biogerontology Research, Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, UK
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Pohjoismäki JLO, Wanrooij S, Hyvärinen AK, Goffart S, Holt IJ, Spelbrink JN, Jacobs HT. Alterations to the expression level of mitochondrial transcription factor A, TFAM, modify the mode of mitochondrial DNA replication in cultured human cells. Nucleic Acids Res 2006; 34:5815-28. [PMID: 17062618 PMCID: PMC1635303 DOI: 10.1093/nar/gkl703] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Mitochondrial transcription factor A (TFAM) is an abundant mitochondrial protein of the HMG superfamily, with various putative roles in mitochondrial DNA (mtDNA) metabolism. In this study we have investigated the effects on mtDNA replication of manipulating TFAM expression in cultured human cells. Mammalian mtDNA replication intermediates (RIs) fall into two classes, whose mechanistic relationship is not properly understood. One class is characterized by extensive RNA incorporation on the lagging strand, whereas the other has the structure of products of conventional, strand-coupled replication. TFAM overexpression increased the overall abundance of RIs and shifted them substantially towards those of the conventional, strand-coupled type. The shift was most pronounced in the rDNA region and at various replication pause sites and was accompanied by a drop in the relative amount of replication-termination intermediates, a substantial reduction in mitochondrial transcripts, mtDNA decatenation and progressive copy number depletion. TFAM overexpression could be partially phenocopied by treatment of cells with dideoxycytidine, suggesting that its effects are partially attributable to a decreased rate of fork progression. TFAM knockdown also resulted in mtDNA depletion, but RIs remained mainly of the ribosubstituted type, although termination intermediates were enhanced. We propose that TFAM influences the mode of mtDNA replication via its combined effects on different aspects of mtDNA metabolism.
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Affiliation(s)
- Jaakko L. O. Pohjoismäki
- Institute of Medical Technology and Tampere University HospitalFI-33014 University of Tampere, Finland
| | - Sjoerd Wanrooij
- Institute of Medical Technology and Tampere University HospitalFI-33014 University of Tampere, Finland
| | - Anne K. Hyvärinen
- Institute of Medical Technology and Tampere University HospitalFI-33014 University of Tampere, Finland
| | - Steffi Goffart
- Institute of Medical Technology and Tampere University HospitalFI-33014 University of Tampere, Finland
| | - Ian J. Holt
- MRC-Dunn Human Nutrition Unit, Hill RoadCambridge CB2 2XY, England, UK
| | - Johannes N. Spelbrink
- Institute of Medical Technology and Tampere University HospitalFI-33014 University of Tampere, Finland
| | - Howard T. Jacobs
- Institute of Medical Technology and Tampere University HospitalFI-33014 University of Tampere, Finland
- IBLS Division of Molecular Genetics, University of GlasgowGlasgow G12 8QQ, Scotland, UK
- To whom correspondence should be addressed. Tel: +358 33 55 17 731; Fax: +358 32 15 77 10;
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Hood DA, Irrcher I, Ljubicic V, Joseph AM. Coordination of metabolic plasticity in skeletal muscle. ACTA ACUST UNITED AC 2006; 209:2265-75. [PMID: 16731803 DOI: 10.1242/jeb.02182] [Citation(s) in RCA: 253] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Skeletal muscle is a highly malleable tissue, capable of pronounced metabolic and morphological adaptations in response to contractile activity (i.e. exercise). Each bout of contractile activity results in a coordinated alteration in the expression of a variety of nuclear DNA and mitochondrial DNA (mtDNA) gene products, leading to phenotypic adaptations. This results in an increase in muscle mitochondrial volume and changes in organelle composition, referred to as mitochondrial biogenesis. The functional consequence of this biogenesis is an improved resistance to fatigue. Signals initiated by the exercise bout involve changes in intracellular Ca2+ as well as alterations in energy status (i.e. ATP/ADP ratio) and the consequent activation of downstream kinases such as AMP kinase and Ca2+-calmodulin-activated kinases. These kinases activate transcription factors that bind DNA to affect the transcription of genes, the most evident manifestation of which occurs during the post-exercise recovery period when energy metabolism is directed toward anabolism, rather than contractile activity. An important protein that is affected by exercise is the transcriptional coactivator PGC-1alpha, which cooperates with multiple transcription factors to induce the expression of nuclear genes encoding mitochondrial proteins. Once translated in the cytosol, these mitochondrially destined proteins are imported into the mitochondrial outer membrane, inner membrane or matrix space via specific import machinery transport components. Contractile activity affects the expression of the import machinery, as well as the kinetics of import, thus facilitating the entry of newly synthesized proteins into the expanding organelle. An important set of proteins that are imported are the mtDNA transcription factors, which influence the expression and replication of mtDNA. While mtDNA contributes only 13 proteins to the synthesis of the organelle, these proteins are vital for the proper assembly of multi-subunit complexes of the respiratory chain, when combined with nuclear-encoded protein subunits. The expansion of skeletal muscle mitochondria during organelle biogenesis involves the assembly of an interconnected network system (i.e. a mitochondrial reticulum). This expansion of membrane size is influenced by the balance between mitochondrial fusion and fission. Thus, mitochondrial biogenesis is an adaptive process that requires the coordination of multiple cellular events, including the transcription of two genomes, the synthesis of lipids and proteins and the stoichiometric assembly of multisubunit protein complexes into a functional respiratory chain. Impairments at any step can lead to defective electron transport, a subsequent failure of ATP production and an inability to maintain energy homeostasis.
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Affiliation(s)
- David A Hood
- School of Kinesiology and Health Science, York University, Toronto, Ontario, M3J 1P3, Canada.
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Noack H, Bednarek T, Heidler J, Ladig R, Holtz J, Szibor M. TFAM-dependent and independent dynamics of mtDNA levels in C2C12 myoblasts caused by redox stress. Biochim Biophys Acta Gen Subj 2006; 1760:141-50. [PMID: 16439064 DOI: 10.1016/j.bbagen.2005.12.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2005] [Revised: 11/11/2005] [Accepted: 12/07/2005] [Indexed: 11/29/2022]
Abstract
TFAM is an essential protein factor for the initiation of transcription of the mtDNA. It also functions as a packaging factor, which stabilizes the mtDNA pool. To investigate the regulatory role of TFAM for regeneration and proliferation of the mtDNA pool, we exposed the muscle cell line C2C12 to a severe redox stress (H2O2) or to a moderate redox stress (GSH depletion), determined the dynamics of the mtDNA levels and correlated this with the TFAM protein levels. H2O2 caused a concentration-dependent loss of mtDNA molecules. The mtDNA levels recovered slowly within 3 days after H2O2 stress. The TFAM protein was less degraded than the mtDNA indicating an accumulation of TFAM protein per mtDNA after H2O2 stress. Overexpression of TFAM did not protect against the mtDNA loss after H2O2 stress but shortened the recovery time. GSH depletion led to a proliferation of the mtDNA pool. Although the mtDNA levels increased the TFAM protein levels were unaffected by the GSH depletion. We conclude that the accumulation of the TFAM protein after H2O2 stress contributes to the regeneration of the mtDNA pool but that other mechanisms, independent from the TFAM protein amount have to be postulated to explain the proliferation of the mtDNA pool after GSH depletion.
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Affiliation(s)
- Heiko Noack
- Institute of Pathophysiology, Martin-Luther-University Halle-Wittenberg, ZAMED, Heinrich-Damerow-Str. 1, 06097 Halle, Germany.
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Pesce V, Cormio A, Fracasso F, Lezza AMS, Cantatore P, Gadaleta MN. Age-Related Changes of Mitochondrial DNA Content and Mitochondrial Genotypic and Phenotypic Alterations in Rat Hind-Limb Skeletal Muscles. J Gerontol A Biol Sci Med Sci 2005; 60:715-23. [PMID: 15983173 DOI: 10.1093/gerona/60.6.715] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Mitochondrial DNA (mtDNA) content relative to nuclear DNA content as well as mitochondrial transcription factor A (TFAM) content was measured in four hind-limb skeletal muscles, namely soleus (S), tibialis anterior (TA), gastrocnemius (G), and extensor digitorum longus (EDL) of adult rats. Content of mtDNA in 6-month-old rats is in the rank order of S > TA > G > EDL, and TFAM content is higher in S than in the other studied muscles. After the rat is 6 months of age, the mtDNA content decreases only in S and TA, whereas the TFAM content increases only in S. Deletions in mtDNA appear quite early in life in S and later on in the other muscles. Fibers defective for mitochondrial respiratory enzymes appear in rats at 15 months of age. In the oldest animals, the highest frequencies of occurrence of mtDNA deletions as well as of mitochondrial phenotypic alterations are found in S according to its highest mtDNA content and oxidative potential.
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Affiliation(s)
- Vito Pesce
- Department of Biochemistry and Molecular Biology, University of Bari, Via Orabona 4, 70125 Bari, Italy
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46
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Rodríguez-Santiago B, Nunes V. Expression of mitochondrial genes and transcription estimation in different brain areas in Alzheimer's disease patients. Neurobiol Dis 2005; 18:296-304. [PMID: 15686958 DOI: 10.1016/j.nbd.2004.10.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2004] [Revised: 09/16/2004] [Accepted: 10/13/2004] [Indexed: 10/26/2022] Open
Abstract
Accumulation of mitochondrial defects is hypothesised to play a role in the complex pathophysiology of the sporadic form of Alzheimer's disease (SAD). Changes in expression of mtDNA encoded genes have been reported in SAD. However no conclusive results were obtained by using different methodologies and analysing distinct transcripts in a variety of brain areas. Here, we measured the expression of five mitochondrial-encoded genes in three brain areas and in lymphocytes from patients and controls by performing reverse transcription followed by quantitative real-time PCR. The analysis of gene expression was also performed by carrying out classic dot-blot experiments to evaluate the two techniques. SAD and control samples showed similar gene expression levels. Estimation of the transcription rate was also measured. No differences were observed when comparing patients and controls. Selective differences in transcription rates were observed only when samples were pooled by tissue, lymphocytes being the tissue with the highest rates.
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Affiliation(s)
- Benjamín Rodríguez-Santiago
- Medical and Molecular Genetics Center-Institut de Recerca Oncologica, IDIBELL, Hospital Duran i Reynals, Gran Via s/n, L'Hospitalet del Llobregat 08907, Barcelona, Spain
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Abstract
Mitochondria are the central processing units for cellular energy metabolism and, in addition to carrying out oxidative phosphorylation, regulate important processes such as apoptosis and calcium homeostasis. Because mitochondria possess a genome that is central to their multiple functions, an understanding of the mechanism of mitochondrial gene expression is required to decipher the many ways mitochondrial dysfunction contributes to human disease. Towards this end, two human transcription factors that are related to rRNA methyltransferases have recently been characterized, providing new insight into the mechanism of mitochondrial transcription and a novel link to maternally inherited deafness. Furthermore, studies in the Saccharomyces cerevisiae model system have revealed a functional coupling of transcription and translation at the inner mitochondrial membrane, where assembly of the oxidative phosphorylation system commences. Defects in an analogous coupling mechanism in humans might underlie the cytochrome oxidase deficiency that causes a form of Leigh Syndrome.
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Affiliation(s)
- Gerald S Shadel
- Department of Pathology, Yale University School of Medicine, 300 Cedar Street, PO Box 208023, New Haven, CT 06520-8023, USA.
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Shen X, Zheng S, Thongboonkerd V, Xu M, Pierce WM, Klein JB, Epstein PN. Cardiac mitochondrial damage and biogenesis in a chronic model of type 1 diabetes. Am J Physiol Endocrinol Metab 2004; 287:E896-905. [PMID: 15280150 DOI: 10.1152/ajpendo.00047.2004] [Citation(s) in RCA: 216] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Diabetic cardiomyopathy is a common complication leading to heightened risk of heart failure and death. In the present report, we performed proteomic analysis on total cardiac proteins from the OVE26 mouse model of type 1 diabetes to identify protein changes that may contribute to diabetic cardiomyopathy. This analysis revealed that a surprising high proportion (12 of 20) of the altered proteins that could be identified by mass spectrometry were of mitochondrial origin. All but one of these proteins were upregulated by diabetes. Quantitative RT-PCR, performed for two of these proteins, indicated that part of the upregulation was attributed to increased messenger RNA levels. Morphological study of diabetic hearts showed significantly increased mitochondrial area and number as well as focal regions with severe damage to mitochondria. Diabetic mitochondria also showed reduced respiratory control ratio (9.63 +/- 0.20 vs. 6.13 +/- 0.41, P < 0.0001), apparently due to reduced state 3 rate, and diminished GSH level (5.5 +/- 0.9 vs. 8.2 +/- 2.5 micromol/mg protein, P < 0.05), indicating impaired mitochondrial function and increased oxidative stress. Further examination revealed increased mitochondrial DNA (1.03 +/- 0.18 vs. 0.69 +/- 0.13 relative copy number, P < 0.001) and a tendency to higher protein yield in OVE26 cardiac mitochondria, as well as increased mRNA level for mitochondrial transcription factor A and two mitochondrial encoded proteins. Taken together, these results show that mitochondria are a primary target in the diabetic heart, probably due to oxidative stress, and that this damage coincides with and may stimulate mitochondrial biogenesis.
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Affiliation(s)
- Xia Shen
- Dept. of Pharmacology and Toxicology, University of Louisville, 570 S. Preston St., Suite 304, Louisville, KY 40202, USA
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49
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Pesce V, Fracasso F, Musicco C, Lezza AMS, Cantatore P, Gadaleta MN. Acetyl-l-Carnitine Dietary Supplementation to Old Rats Increases Mitochondrial Transcription Factor A Content in Rat Hindlimb Skeletal Muscles. Ann N Y Acad Sci 2004; 1019:430-3. [PMID: 15247059 DOI: 10.1196/annals.1297.077] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Acetyl-L-carnitine (ALCAR) fed to old rats has been reported to partially restore mitochondrial function and ambulatory activity. The results of the effect of ALCAR dietary supplementation to 28-month-old rats on mitochondrial transcription factor A (TFAM) content of rat hindlimb skeletal muscles are reported.
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Affiliation(s)
- V Pesce
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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