1
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Wang W, Zhang M, Hou X, Xiao B, Gao Y. Identification of the CsFtsH genes from Camellia sinensis reveals its potential role in leaf color phenotype. Gene 2024; 927:148672. [PMID: 38857713 DOI: 10.1016/j.gene.2024.148672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 05/10/2024] [Accepted: 06/07/2024] [Indexed: 06/12/2024]
Abstract
The filamentation temperature-sensitive H (FtsH) metalloprotease participates in the chloroplast photosystem II (PSII) repair cycle, playing a crucial role in regulating leaf coloration. However, the evolutionary history and biological function of the FtsH family in albino tea plants are still unknown. In this study, 35 CsFtsH members, including 7 CsFtsH-like (CsFtsHi1-CsFtsHi7) proteins, mapping onto 11 chromosomes in 6 subgroups, were identified in the 'Shuchazao2' tea genome, and their exon/intron structure, domain characteristics, collinearity, protein interaction network, and secondary structure were comprehensively analyzed. Furthermore, real-time fluorescence quantitative PCR (RT-qPCR) analysis revealed that the expression levels of CsFtsH1/2/5/8 were significantly positively correlated with the leaf color of tea plants. The subcellular localization revealed that they were located in the chloroplast. The transgenic Arabidopsis has demonstrated that CsFtsH2 and CsFtsH5 could restore the chlorophyll content and chlorophyll fluorescence intensity in var1 and var2 mutants, respectively. Moreover, protein-protein interactions have confirmed that CsFtsH1 with CsFtsH5, and CsFtsH2 with CsFtsH8 could form a hetero-comples and function in chloroplasts. In summary, this study aims to not only increase the understanding of the underlying molecular mechanisms of CsFtsH but also to provide a solid and detailed theoretical foundation for the breeding of albino tea plant varieties.
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Affiliation(s)
- Wenjing Wang
- College of Horticulture, Northwest A&F University, Yangling 712100, China.
| | - Mengyuan Zhang
- College of Horticulture, Northwest A&F University, Yangling 712100, China.
| | - Xinru Hou
- College of Horticulture, Northwest A&F University, Yangling 712100, China.
| | - Bin Xiao
- College of Horticulture, Northwest A&F University, Yangling 712100, China; Fu Tea Research and Development Centre, Northwest A&F University, Jingyang 713700, China.
| | - Yuefang Gao
- College of Horticulture, Northwest A&F University, Yangling 712100, China; Fu Tea Research and Development Centre, Northwest A&F University, Jingyang 713700, China.
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2
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Ma X, Niu M, Ni HM, Ding WX. Mitochondrial dynamics, quality control, and mtDNA in alcohol-associated liver disease and liver cancer. Hepatology 2024:01515467-990000000-00861. [PMID: 38683546 DOI: 10.1097/hep.0000000000000910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Accepted: 04/05/2024] [Indexed: 05/01/2024]
Abstract
Mitochondria are intracellular organelles responsible for energy production, glucose and lipid metabolism, cell death, cell proliferation, and innate immune response. Mitochondria are highly dynamic organelles that constantly undergo fission, fusion, and intracellular trafficking, as well as degradation and biogenesis. Mitochondrial dysfunction has been implicated in a variety of chronic liver diseases including alcohol-associated liver disease, metabolic dysfunction-associated steatohepatitis, and HCC. In this review, we provide a detailed overview of mitochondrial dynamics, mitophagy, and mitochondrial DNA-mediated innate immune response, and how dysregulation of these mitochondrial processes affects the pathogenesis of alcohol-associated liver disease and HCC. Mitochondrial dynamics and mitochondrial DNA-mediated innate immune response may thereby represent an attractive therapeutic target for ameliorating alcohol-associated liver disease and alcohol-associated HCC.
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Affiliation(s)
- Xiaowen Ma
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Mengwei Niu
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Hong-Min Ni
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Wen-Xing Ding
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, USA
- Department of Internal Medicine, Division of Gastroenterology, Hepatology and Mobility, University of Kansas Medical Center, Kansas City, Kansas, USA
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3
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Qasem B, Dąbrowska A, Króliczewski J, Łyczko J, Marycz K. Trodusquemine (MSI-1436) Restores Metabolic Flexibility and Mitochondrial Dynamics in Insulin-Resistant Equine Hepatic Progenitor Cells (HPCs). Cells 2024; 13:152. [PMID: 38247843 PMCID: PMC10814577 DOI: 10.3390/cells13020152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 12/31/2023] [Accepted: 01/12/2024] [Indexed: 01/23/2024] Open
Abstract
Equine metabolic syndrome (EMS) is a significant global health concern in veterinary medicine. There is increasing interest in utilizing molecular agents to modulate hepatocyte function for potential clinical applications. Recent studies have shown promising results in inhibiting protein tyrosine phosphatase (PTP1B) to maintain cell function in various models. In this study, we investigated the effects of the inhibitor Trodusquemine (MSI-1436) on equine hepatic progenitor cells (HPCs) under lipotoxic conditions. We examined proliferative activity, glucose uptake, and mitochondrial morphogenesis. Our study found that MSI-1436 promotes HPC entry into the cell cycle and protects them from palmitate-induced apoptosis by regulating mitochondrial dynamics and biogenesis. MSI-1436 also increases glucose uptake and protects HPCs from palmitate-induced stress by reorganizing the cells' morphological architecture. Furthermore, our findings suggest that MSI-1436 enhances 2-NBDG uptake by increasing the expression of SIRT1, which is associated with liver insulin sensitivity. It also promotes mitochondrial dynamics by modulating mitochondria quantity and morphotype as well as increasing the expression of PINK1, MFN1, and MFN2. Our study provides evidence that MSI-1436 has a positive impact on equine hepatic progenitor cells, indicating its potential therapeutic value in treating EMS and insulin dysregulation.
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Affiliation(s)
- Badr Qasem
- Department of Experimental Biology, Faculty of Biology and Animal Science, Wrocław University of Environmental and Life Sciences, Norwida 27B, 50-375 Wrocław, Poland; (B.Q.); (A.D.); (J.K.)
| | - Agnieszka Dąbrowska
- Department of Experimental Biology, Faculty of Biology and Animal Science, Wrocław University of Environmental and Life Sciences, Norwida 27B, 50-375 Wrocław, Poland; (B.Q.); (A.D.); (J.K.)
| | - Jarosław Króliczewski
- Department of Experimental Biology, Faculty of Biology and Animal Science, Wrocław University of Environmental and Life Sciences, Norwida 27B, 50-375 Wrocław, Poland; (B.Q.); (A.D.); (J.K.)
| | - Jacek Łyczko
- Department of Food Chemistry and Biocatalysis, Wrocław University of Environmental and Life Sciences, 50-375 Wrocław, Poland;
| | - Krzysztof Marycz
- Department of Experimental Biology, Faculty of Biology and Animal Science, Wrocław University of Environmental and Life Sciences, Norwida 27B, 50-375 Wrocław, Poland; (B.Q.); (A.D.); (J.K.)
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95516, USA
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4
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Ma X, Manley S, Qian H, Li Y, Zhang C, Li K, Ding B, Guo F, Chen A, Zhang X, Liu M, Hao M, Kugler B, Morris EM, Thyfault J, Yang L, Sesaki H, Ni HM, McBride H, Ding WX. Mitochondria-lysosome-related organelles mediate mitochondrial clearance during cellular dedifferentiation. Cell Rep 2023; 42:113291. [PMID: 37862166 PMCID: PMC10842364 DOI: 10.1016/j.celrep.2023.113291] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 08/01/2023] [Accepted: 09/29/2023] [Indexed: 10/22/2023] Open
Abstract
Dysfunctional mitochondria are removed via multiple pathways, such as mitophagy, a selective autophagy process. Here, we identify an intracellular hybrid mitochondria-lysosome organelle (termed the mitochondria-lysosome-related organelle [MLRO]), which regulates mitochondrial homeostasis independent of canonical mitophagy during hepatocyte dedifferentiation. The MLRO is an electron-dense organelle that has either a single or double membrane with both mitochondria and lysosome markers. Mechanistically, the MLRO is likely formed from the fusion of mitochondria-derived vesicles (MDVs) with lysosomes through a PARKIN-, ATG5-, and DRP1-independent process, which is negatively regulated by transcription factor EB (TFEB) and associated with mitochondrial protein degradation and hepatocyte dedifferentiation. The MLRO, which is galectin-3 positive, is reminiscent of damaged lysosome and could be cleared by overexpression of TFEB, resulting in attenuation of hepatocyte dedifferentiation. Together, results from this study suggest that the MLRO may act as an alternative mechanism for mitochondrial quality control independent of canonical autophagy/mitophagy involved in cell dedifferentiation.
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Affiliation(s)
- Xiaowen Ma
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Sharon Manley
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Hui Qian
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Yuan Li
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Chen Zhang
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Kevin Li
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Benjamin Ding
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Fengli Guo
- Stowers Institute for Medical Research, Kansas City, MO, USA; Department of Pathology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Allen Chen
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Xing Zhang
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Meilian Liu
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Meihua Hao
- Department of Anatomy and Cell Biology, Fraternal Order of Eagles Diabetes Research Center, Pappajohn Biomedical Institute, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - Benjamin Kugler
- Department of Cell Biology and Physiology, University of Kansas Medical Center, Kansas City, KS, USA
| | - E Matthew Morris
- Department of Cell Biology and Physiology, University of Kansas Medical Center, Kansas City, KS, USA
| | - John Thyfault
- Department of Cell Biology and Physiology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Ling Yang
- Department of Anatomy and Cell Biology, Fraternal Order of Eagles Diabetes Research Center, Pappajohn Biomedical Institute, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - Hiromi Sesaki
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Hong-Min Ni
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Heidi McBride
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Wen-Xing Ding
- Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, Kansas City, KS 66160, USA; Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS, USA.
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5
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Ma C, Wang C, Luo D, Yan L, Yang W, Li N, Gao N. Structural insights into the membrane microdomain organization by SPFH family proteins. Cell Res 2022; 32:176-189. [PMID: 34975153 PMCID: PMC8807802 DOI: 10.1038/s41422-021-00598-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Accepted: 11/09/2021] [Indexed: 02/03/2023] Open
Abstract
The lateral segregation of membrane constituents into functional microdomains, conceptually known as lipid raft, is a universal organization principle for cellular membranes in both prokaryotes and eukaryotes. The widespread Stomatin, Prohibitin, Flotillin, and HflK/C (SPFH) family proteins are enriched in functional membrane microdomains at various subcellular locations, and therefore were hypothesized to play a scaffolding role in microdomain formation. In addition, many SPFH proteins are also implicated in highly specific processes occurring on the membrane. However, none of these functions is understood at the molecular level. Here we report the structure of a supramolecular complex that is isolated from bacterial membrane microdomains and contains two SPFH proteins (HflK and HflC) and a membrane-anchored AAA+ protease FtsH. HflK and HflC form a circular 24-mer assembly, featuring a laterally segregated membrane microdomain (20 nm in diameter) bordered by transmembrane domains of HflK/C and a completely sealed periplasmic vault. Four FtsH hexamers are embedded inside this microdomain through interactions with the inner surface of the vault. These observations provide a mechanistic explanation for the role of HflK/C and their mitochondrial homologs prohibitins in regulating membrane-bound AAA+ proteases, and suggest a general model for the organization and functionalization of membrane microdomains by SPFH proteins.
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Affiliation(s)
- Chengying Ma
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Chengkun Wang
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Dingyi Luo
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Lu Yan
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Wenxian Yang
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Ningning Li
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Ning Gao
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, Beijing, China ,grid.11135.370000 0001 2256 9319National Biomedical Imaging Center, Peking University, Beijing, China
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6
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Pacheco R, Quezada SA, Kalergis AM, Becker MI, Ferreira J, De Ioannes AE. Allergens of the urushiol family promote mitochondrial dysfunction by inhibiting the electron transport at the level of cytochromes b and chemically modify cytochrome c 1. Biol Res 2021; 54:35. [PMID: 34711292 PMCID: PMC8554850 DOI: 10.1186/s40659-021-00357-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 10/06/2021] [Indexed: 11/10/2022] Open
Abstract
Background Urushiols are pro-electrophilic haptens that cause severe contact dermatitis mediated by CD8+ effector T-cells and downregulated by CD4+ T-cells. However, the molecular mechanism by which urushiols stimulate innate immunity in the initial stages of this allergic reaction is poorly understood. Here we explore the sub-cellular mechanisms by which urushiols initiate the allergic response. Results Electron microscopy observations of mouse ears exposed to litreol (3-n-pentadecyl-10-enyl-catechol]) showed keratinocytes containing swollen mitochondria with round electron-dense inclusion bodies in the matrix. Biochemical analyses of sub-mitochondrial fractions revealed an inhibitory effect of urushiols on electron flow through the mitochondrial respiratory chain, which requires both the aliphatic and catecholic moieties of these allergens. Moreover, urushiols extracted from poison ivy/oak (mixtures of 3-n-pentadecyl-8,11,13 enyl/3-n-heptadecyl-8,11 enyl catechol) exerted a higher inhibitory effect on mitochondrial respiration than did pentadecyl catechol or litreol, indicating that the higher number of unsaturations in the aliphatic chain, stronger the allergenicity of urushiols. Furthermore, the analysis of radioactive proteins isolated from mitochondria incubated with 3H-litreol, indicated that this urushiol was bound to cytochrome c1. According to the proximity of cytochromes c1 and b, functional evidence indicated the site of electron flow inhibition was within complex III, in between cytochromes bL (cyt b566) and bH (cyt b562). Conclusion Our data provide functional and molecular evidence indicating that the interruption of the mitochondrial electron transport chain constitutes an important mechanism by which urushiols initiates the allergic response. Thus, mitochondria may constitute a source of cellular targets for generating neoantigens involved in the T-cell mediated allergy induced by urushiols. Supplementary Information The online version contains supplementary material available at 10.1186/s40659-021-00357-z.
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Affiliation(s)
- Rodrigo Pacheco
- Laboratorio de Neuroinmunología, Fundación Ciencia & Vida, Santiago, Chile. .,Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile.
| | - Sergio A Quezada
- Cancer Immunology Unit, University College London (UCL) Cancer Institute, London, England, UK
| | - Alexis M Kalergis
- Instituto Milenio de Inmunología e Inmunoterapia, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Departamento de Endocrinología, Facultad de Medicina, Pontificia Universidad Católica, Santiago, Chile
| | - María Inés Becker
- Fundación Ciencia y Tecnología para el Desarrollo (FUCITED), Santiago, Chile.,Department of Research and Development, Biosonda Corporation, Santiago, Chile.,Faculty of Physical and Mathematical Sciences, Department of Chemical Engineering, Biotechnology and Materials, Universidad de Chile, Santiago, Chile
| | - Jorge Ferreira
- Faculty of Medicine, Institute of Biomedical Sciences, Molecular and Clinical Pharmacology Program, Universidad de Chile, Santiago, Chile
| | - Alfredo E De Ioannes
- Department of Research and Development, Biosonda Corporation, Santiago, Chile.,Faculty of Physical and Mathematical Sciences, Department of Chemical Engineering, Biotechnology and Materials, Universidad de Chile, Santiago, Chile.,Faculty of Medicine, Institute of Biomedical Sciences, Molecular and Clinical Pharmacology Program, Universidad de Chile, Santiago, Chile
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7
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Hannah-Shmouni F, MacNeil L, Brady L, Nilsson MI, Tarnopolsky M. Expanding the Clinical Spectrum of LONP1-Related Mitochondrial Cytopathy. Front Neurol 2019; 10:981. [PMID: 31636596 PMCID: PMC6787162 DOI: 10.3389/fneur.2019.00981] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 08/28/2019] [Indexed: 12/12/2022] Open
Abstract
Pathogenic variants in the LONP1 gene have been associated with CODAS syndrome (Cerebral, Ocular, Dental, Auricular, and Skeletal Anomalies Syndrome). A recent report identified the first newborn case with LONP1-related mitochondrial cytopathy due to a compound heterozygous pathogenic variant in LONP1 without features of CODAS. The proband had manifested with severe congenital lactic acidosis and profound multiple respiratory chain complex activity deficiencies associated with the quantitative loss of mtDNA copy number in muscle. A subsequent report identified two siblings with regression during infancy, profound hypotonia and muscle weakness, severe intellectual disability, progressive cerebellar atrophy, where muscle biopsy showed an electron dense mitochondrial inclusions without ragged-red fibers and normal electron transport chain enzyme activities. Here, we report an additional case of autosomal recessive mitochondrial cytopathy due to a homozygous missense variant in LONP1 that was identified on whole exome sequencing (c.810G > A; p.D463N). The proband, a 20-year-old male born to consanguineous parents, presented with global developmental delay, emotional outbursts, speech and swallowing difficulties, hypotonia, and ataxia since childhood. Muscle biopsy showed massive granular bodies, increased oxidative stress, and autophagic block and reduced mitochondrial state 3 respiration. We have identified another case of LONP1-related mitochondrial cytopathy further confirming a neurological phenotype without CODAS features.
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Affiliation(s)
- Fady Hannah-Shmouni
- Clinical Biochemical Genetics, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada.,Section on Endocrinology and Genetics, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Lauren MacNeil
- Division of Pediatric Laboratory Medicine, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Lauren Brady
- Department of Pediatrics, McMaster University, Hamilton, ON, Canada
| | - Mats I Nilsson
- Department of Pediatrics, McMaster University, Hamilton, ON, Canada
| | - Mark Tarnopolsky
- Department of Pediatrics, McMaster University, Hamilton, ON, Canada
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8
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Antoniou CK, Manolakou P, Magkas N, Konstantinou K, Chrysohoou C, Dilaveris P, Gatzoulis KA, Tousoulis D. Cardiac Resynchronisation Therapy and Cellular Bioenergetics: Effects Beyond Chamber Mechanics. Eur Cardiol 2019; 14:33-44. [PMID: 31131035 PMCID: PMC6523053 DOI: 10.15420/ecr.2019.2.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Cardiac resynchronisation therapy is a cornerstone in the treatment of advanced dyssynchronous heart failure. However, despite its widespread clinical application, precise mechanisms through which it exerts its beneficial effects remain elusive. Several studies have pointed to a metabolic component suggesting that, both in concert with alterations in chamber mechanics and independently of them, resynchronisation reverses detrimental changes to cellular metabolism, increasing energy efficiency and metabolic reserve. These actions could partially account for the existence of responders that improve functionally but not echocardiographically. This article will attempt to summarise key components of cardiomyocyte metabolism in health and heart failure, with a focus on the dyssynchronous variant. Both chamber mechanics-related and -unrelated pathways of resynchronisation effects on bioenergetics – stemming from the ultramicroscopic level – and a possible common underlying mechanism relating mechanosensing to metabolism through the cytoskeleton will be presented. Improved insights regarding the cellular and molecular effects of resynchronisation on bioenergetics will promote our understanding of non-response, optimal device programming and lead to better patient care.
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Affiliation(s)
| | - Panagiota Manolakou
- First Department of Cardiology, School of Medicine, National and Kapodistrian University of Athens Athens, Greece
| | - Nikolaos Magkas
- First Department of Cardiology, School of Medicine, National and Kapodistrian University of Athens Athens, Greece
| | - Konstantinos Konstantinou
- First Department of Cardiology, School of Medicine, National and Kapodistrian University of Athens Athens, Greece
| | - Christina Chrysohoou
- First Department of Cardiology, School of Medicine, National and Kapodistrian University of Athens Athens, Greece
| | - Polychronis Dilaveris
- First Department of Cardiology, School of Medicine, National and Kapodistrian University of Athens Athens, Greece
| | - Konstantinos A Gatzoulis
- First Department of Cardiology, School of Medicine, National and Kapodistrian University of Athens Athens, Greece
| | - Dimitrios Tousoulis
- First Department of Cardiology, School of Medicine, National and Kapodistrian University of Athens Athens, Greece
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9
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Peter B, Waddington CL, Oláhová M, Sommerville EW, Hopton S, Pyle A, Champion M, Ohlson M, Siibak T, Chrzanowska-Lightowlers ZMA, Taylor RW, Falkenberg M, Lightowlers RN. Defective mitochondrial protease LonP1 can cause classical mitochondrial disease. Hum Mol Genet 2019. [PMID: 29518248 PMCID: PMC5932559 DOI: 10.1093/hmg/ddy080] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
LonP1 is a mitochondrial matrix protease whose selective substrate specificity is essential for maintaining mitochondrial homeostasis. Recessively inherited, pathogenic defects in LonP1 have been previously reported to underlie cerebral, ocular, dental, auricular and skeletal anomalies (CODAS) syndrome, a complex multisystemic and developmental disorder. Intriguingly, although classical mitochondrial disease presentations are well-known to exhibit marked clinical heterogeneity, the skeletal and dental features associated with CODAS syndrome are pathognomonic. We have applied whole exome sequencing to a patient with congenital lactic acidosis, muscle weakness, profound deficiencies in mitochondrial oxidative phosphorylation associated with loss of mtDNA copy number and MRI abnormalities consistent with Leigh syndrome, identifying biallelic variants in the LONP1 (NM_004793.3) gene; c.1693T > C predicting p.(Tyr565His) and c.2197G > A predicting p.(Glu733Lys); no evidence of the classical skeletal or dental defects observed in CODAS syndrome patients were noted in our patient. In vitro experiments confirmed the p.(Tyr565His) LonP1 mutant alone could not bind or degrade a substrate, consistent with the predicted function of Tyr565, whilst a second missense [p.(Glu733Lys)] variant had minimal effect. Mixtures of p.(Tyr565His) mutant and wild-type LonP1 retained partial protease activity but this was severely depleted when the p.(Tyr565His) mutant was mixed with the p.(Glu733Lys) mutant, data consistent with the compound heterozygosity detected in our patient. In summary, we conclude that pathogenic LONP1 variants can lead to a classical mitochondrial disease presentations associated with severe biochemical defects in oxidative phosphorylation in clinically relevant tissues.
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Affiliation(s)
- Bradley Peter
- Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Christie L Waddington
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - Monika Oláhová
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - Ewen W Sommerville
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, UK.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Sila Hopton
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - Angela Pyle
- Wellcome Centre for Mitochondrial Research, Institute of Genetics, The Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - Michael Champion
- Department of Inherited Metabolic Disease, Guy's and St Thomas' NHS Foundation Trusts, Evelina London Children's Hospital, London, UK
| | - Monica Ohlson
- Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Triinu Siibak
- Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | | | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - Maria Falkenberg
- Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Robert N Lightowlers
- Wellcome Centre for Mitochondrial Research, Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne, UK
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10
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Durand A, Bourbon ML, Steunou AS, Khalfaoui-Hassani B, Legrand C, Guitton A, Astier C, Ouchane S. Biogenesis of the bacterial cbb3 cytochrome c oxidase: Active subcomplexes support a sequential assembly model. J Biol Chem 2017; 293:808-818. [PMID: 29150446 DOI: 10.1074/jbc.m117.805184] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 10/30/2017] [Indexed: 11/06/2022] Open
Abstract
The cbb3 oxidase has a high affinity for oxygen and is required for growth of bacteria, including pathogens, in oxygen-limited environments. However, the assembly of this oxidase is poorly understood. Most cbb3 are composed of four subunits: the catalytic CcoN subunit, the two cytochrome c subunits (CcoO and CcoP) involved in electron transfer, and the small CcoQ subunit with an unclear function. Here, we address the role of these four subunits in cbb3 biogenesis in the purple bacterium Rubrivivax gelatinosus Analyses of membrane proteins from different mutants revealed the presence of active CcoNQO and CcoNO subcomplexes and also showed that the CcoP subunit is not essential for their assembly. However, CcoP was required for the oxygen reduction activity in the absence of CcoQ. We also found that CcoQ is dispensable for forming an active CcoNOP subcomplex in membranes. CcoNOP exhibited oxygen reductase activity, indicating that the cofactors (hemes b and copper for CcoN and cytochromes c for CcoO and CcoP) were present within the subunits. Finally, we discovered the presence of a CcoNQ subcomplex and showed that CcoN is the required anchor for the assembly of the full CcoNQOP complex. On the basis of these findings, we propose a sequential assembly model in which the CcoQ subunit is required for the early maturation step: CcoQ first associates with CcoN before the CcoNQ-CcoO interaction. CcoP associates to CcoNQO subcomplex in the late maturation step, and once the CcoNQOP complex is fully formed, CcoQ is released for degradation by the FtsH protease. This model could be conserved in other bacteria, including the pathogenic bacteria lacking the assembly factor CcoH as in R. gelatinosus.
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Affiliation(s)
- Anne Durand
- From the Institute for Integrative Biology of the Cell (I2BC), Commissariat à l'Énergie Atomique, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette Cedex, France
| | - Marie-Line Bourbon
- From the Institute for Integrative Biology of the Cell (I2BC), Commissariat à l'Énergie Atomique, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette Cedex, France
| | - Anne-Soisig Steunou
- From the Institute for Integrative Biology of the Cell (I2BC), Commissariat à l'Énergie Atomique, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette Cedex, France
| | - Bahia Khalfaoui-Hassani
- From the Institute for Integrative Biology of the Cell (I2BC), Commissariat à l'Énergie Atomique, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette Cedex, France
| | - Camille Legrand
- From the Institute for Integrative Biology of the Cell (I2BC), Commissariat à l'Énergie Atomique, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette Cedex, France
| | - Audrey Guitton
- From the Institute for Integrative Biology of the Cell (I2BC), Commissariat à l'Énergie Atomique, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette Cedex, France
| | - Chantal Astier
- From the Institute for Integrative Biology of the Cell (I2BC), Commissariat à l'Énergie Atomique, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette Cedex, France
| | - Soufian Ouchane
- From the Institute for Integrative Biology of the Cell (I2BC), Commissariat à l'Énergie Atomique, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette Cedex, France
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11
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Levytskyy RM, Bohovych I, Khalimonchuk O. Metalloproteases of the Inner Mitochondrial Membrane. Biochemistry 2017; 56:4737-4746. [PMID: 28806058 DOI: 10.1021/acs.biochem.7b00663] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The inner mitochondrial membrane (IM) is among the most protein-rich cellular compartments. The metastable IM subproteome where the concentration of proteins is approaching oversaturation creates a challenging protein folding environment with a high probability of protein malfunction or aggregation. Failure to maintain protein homeostasis in such a setting can impair the functional integrity of the mitochondria and drive clinical manifestations. The IM is equipped with a series of highly conserved, proteolytic complexes dedicated to the maintenance of normal protein homeostasis within this mitochondrial subcompartment. Particularly important is a group of membrane-anchored metallopeptidases commonly known as m-AAA and i-AAA proteases, and the ATP-independent Oma1 protease. Herein, we will summarize the current biochemical knowledge of these proteolytic machines and discuss recent advances in our understanding of mechanistic aspects of their functioning.
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Affiliation(s)
- Roman M Levytskyy
- Department of Biochemistry, University of Nebraska-Lincoln , Lincoln, Nebraska 68588-0664, United States
| | - Iryna Bohovych
- Department of Biochemistry, University of Nebraska-Lincoln , Lincoln, Nebraska 68588-0664, United States
| | - Oleh Khalimonchuk
- Department of Biochemistry, University of Nebraska-Lincoln , Lincoln, Nebraska 68588-0664, United States.,Nebraska Redox Biology Center, University of Nebraska-Lincoln , Lincoln, Nebraska 68588-0662, United States.,Fred & Pamela Buffett Cancer Center , Omaha, Nebraska 68106, United States
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12
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Kenny TC, Germain D. From discovery of the CHOP axis and targeting ClpP to the identification of additional axes of the UPRmt driven by the estrogen receptor and SIRT3. J Bioenerg Biomembr 2017; 49:297-305. [PMID: 28799020 DOI: 10.1007/s10863-017-9722-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 05/11/2017] [Indexed: 12/18/2022]
Abstract
The mitochondrial UPR (UPRmt) is rapidly gaining attention. While most studies on the UPRmt have focused on its role in aging, emerging studies suggest an important role of the UPRmt in cancer. Further, several of the players of the UPRmt in mammalian cells have well reported roles in the maintenance of the organelle. The goal of this review is to emphasize aspects of the UPRmt that have been overlooked in the current literature, describe the role of specific players of the UPRmt in the biology of the mitochondria and highlight the intriguing possibility that targeting the UPRmt in cancer may be already within reach.
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Affiliation(s)
- Timothy C Kenny
- Department of Medicine, Division of Hematology/Oncology, Icahn School of Medicine at Mount Sinai, Tisch Cancer Institute, New York, NY, 10029, USA
| | - Doris Germain
- Department of Medicine, Division of Hematology/Oncology, Icahn School of Medicine at Mount Sinai, Tisch Cancer Institute, New York, NY, 10029, USA.
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13
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Liu Q, Wang X, Qin J, Cheng S, Yeo WS, He L, Ma X, Liu X, Li M, Bae T. The ATP-Dependent Protease ClpP Inhibits Biofilm Formation by Regulating Agr and Cell Wall Hydrolase Sle1 in Staphylococcus aureus. Front Cell Infect Microbiol 2017; 7:181. [PMID: 28555174 PMCID: PMC5430930 DOI: 10.3389/fcimb.2017.00181] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 04/27/2017] [Indexed: 12/27/2022] Open
Abstract
Biofilm causes hospital-associated infections on indwelling medical devices. In Staphylococcus aureus, Biofilm formation is controlled by intricately coordinated network of regulating systems, of which the ATP-dependent protease ClpP shows an inhibitory effect. Here, we demonstrate that the inhibitory effect of ClpP on biofilm formation is through Agr and the cell wall hydrolase Sle1. Biofilm formed by clpP mutant consists of proteins and extracellular DNA (eDNA). The increase of the protein was, at least in part, due to the reduced protease activity of the mutant, which was caused by the decreased activity of agr. On the other hand, the increase of eDNA was due to increased cell lysis caused by the higher level of Sle1. Indeed, as compared with wild type, the clpP mutant excreted an increased level of eDNA, and showed higher sensitivity to Triton-induced autolysis. The deletion of sle1 in the clpP mutant decreased the biofilm formation, the level of eDNA, and the Triton-induced autolysis to wild-type levels. Despite the increased biofilm formation capability, however, the clpP mutant showed significantly reduced virulence in a murine model of subcutaneous foreign body infection, indicating that the increased biofilm formation capability cannot compensate for the intrinsic functions of ClpP during infection.
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Affiliation(s)
- Qian Liu
- Department of Laboratory Medicine, School of Medicine, Ren Ji Hospital, Shanghai Jiao Tong UniversityShanghai, China
| | - Xing Wang
- Department of Laboratory Medicine, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong UniversityShanghai, China
| | - Juanxiu Qin
- Department of Laboratory Medicine, School of Medicine, Ren Ji Hospital, Shanghai Jiao Tong UniversityShanghai, China
| | - Sen Cheng
- Institute of Analytical Chemistry and Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking UniversityBeijing, China
| | - Won-Sik Yeo
- Department of Microbiology and Immunology, Indiana University School of Medicine-NorthwestGary, IN, USA
| | - Lei He
- Department of Laboratory Medicine, School of Medicine, Ren Ji Hospital, Shanghai Jiao Tong UniversityShanghai, China
| | - Xiaowei Ma
- Department of Laboratory Medicine, School of Medicine, Ren Ji Hospital, Shanghai Jiao Tong UniversityShanghai, China
| | - Xiaoyun Liu
- Institute of Analytical Chemistry and Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking UniversityBeijing, China
| | - Min Li
- Department of Laboratory Medicine, School of Medicine, Ren Ji Hospital, Shanghai Jiao Tong UniversityShanghai, China
| | - Taeok Bae
- Department of Microbiology and Immunology, Indiana University School of Medicine-NorthwestGary, IN, USA
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14
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Hatakeyama H, Goto YI. Respiratory Chain Complex Disorganization Impairs Mitochondrial and Cellular Integrity: Phenotypic Variation in Cytochrome c Oxidase Deficiency. THE AMERICAN JOURNAL OF PATHOLOGY 2016; 187:110-121. [PMID: 27855277 DOI: 10.1016/j.ajpath.2016.09.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 08/23/2016] [Accepted: 09/19/2016] [Indexed: 01/19/2023]
Abstract
The relationships between the molecular abnormalities in mitochondrial respiratory chain complexes and their negative contributions to mitochondrial and cellular functions have been proved to be essential for better understandings in mitochondrial medicine. Herein, we established the method to identify disease phenotypic differences among patients with muscle histopathological cytochrome c oxidase (COX) deficiency, as one of the representative clinical features in mitochondrial diseases, by using patients' myoblasts that are derived from biopsied skeletal muscle tissues. We identified two obviously different severities in molecular diagnostic criteria of COX deficiency among patients: structurally stable, but functionally mild/moderate defect and severe functional defect with the disrupted COX holoenzyme structure. COX holoenzyme disorganization actually triggered several mitochondrial dysfunctions, including the decreased ATP level, the increased oxidative stress level, and the damaged membrane potential level, all of which lead to the deteriorated cellular growth, the accelerated cellular senescence, and the induced apoptotic cell death. Our cell-based in vitro diagnostic approaches would be widely applicable to understanding patient-specific pathomechanism in various types of mitochondrial diseases, including other respiratory chain complex deficiencies and other mitochondrial metabolic enzyme deficiencies.
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Affiliation(s)
- Hideyuki Hatakeyama
- Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan; AMED-CREST, Japan Agency for Medical Research and Development, Tokyo, Japan.
| | - Yu-Ichi Goto
- Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan; AMED-CREST, Japan Agency for Medical Research and Development, Tokyo, Japan; Medical Genome Center, National Center of Neurology and Psychiatry, Tokyo, Japan.
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15
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Gao G, Moyes CD. Evaluating the role of NRF-1 in the regulation of the goldfish COX4-1 gene in response to temperature. ACTA ACUST UNITED AC 2016; 219:3019-3027. [PMID: 27471277 DOI: 10.1242/jeb.141184] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 07/18/2016] [Indexed: 12/19/2022]
Abstract
Cold acclimation in fish typically increases muscle mitochondrial enzymes. In mammals, stressors that increase mitochondrial content are mediated though transcriptional regulators, including nuclear respiratory factor-1 (NRF-1). Focusing on the goldfish gene for cytochrome c oxidase (COX) subunit 4-1, we analysed the regulatory regions in various contexts to identify a mechanistic link between NRF-1 and cold-induced mitochondrial proliferation. Promoter analysis implicated two putative NRF-1 sites: one in the proximal promoter and a second in exon 1, which encodes the 5' untranslated region (5'-UTR). Transfection into mouse myoblasts showed that deletion of a region that included the proximal NRF-1 site reduced promoter activity by 30%; however, mutagenesis of the specific sequence had no effect. Thermal sensitivity analyses performed in rainbow trout gonadal fibroblasts (RTG-2) showed no effect of temperature (4 vs 19°C) on reporter gene expression. Likewise, reporters injected into muscle of thermally acclimated goldfish (4 vs 26°C) showed no elevation in expression. There was no difference in thermal responses of COX4-1 promoter reporters constructed from homologous regions of eurythermal goldfish and stenothermal zebrafish genes. NRF-1 chromatin immunoprecipitation of thermally acclimated goldfish muscle showed no temperature effect on NRF-1 binding to either the proximal promoter or 5'-UTR. It remains possible that the cold-induced upregulation of COX4-1 expression is a result of NRF-1 binding to distal regulatory regions or through indirect effects on other transcription factors. However, the proximal promoter does not appear to play a role in mediating the thermal response of the COX4-1 gene in fish.
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Affiliation(s)
- Ge Gao
- Department of Biology, Queen's University, Kingston, Canada K7L 3N6
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16
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Qi Y, Liu H, Daniels MP, Zhang G, Xu H. Loss of Drosophila i-AAA protease, dYME1L, causes abnormal mitochondria and apoptotic degeneration. Cell Death Differ 2016; 23:291-302. [PMID: 26160069 PMCID: PMC4716308 DOI: 10.1038/cdd.2015.94] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 05/30/2015] [Accepted: 06/05/2015] [Indexed: 01/22/2023] Open
Abstract
Mitochondrial AAA (ATPases Associated with diverse cellular Activities) proteases i-AAA (intermembrane space-AAA) and m-AAA (matrix-AAA) are closely related and have major roles in inner membrane protein homeostasis. Mutations of m-AAA proteases are associated with neuromuscular disorders in humans. However, the role of i-AAA in metazoans is poorly understood. We generated a deletion affecting Drosophila i-AAA, dYME1L (dYME1L(del)). Mutant flies exhibited premature aging, progressive locomotor deficiency and neurodegeneration that resemble some key features of m-AAA diseases. dYME1L(del) flies displayed elevated mitochondrial unfolded protein stress and irregular cristae. Aged dYME1L(del) flies had reduced complex I (NADH/ubiquinone oxidoreductase) activity, increased level of reactive oxygen species (ROS), severely disorganized mitochondrial membranes and increased apoptosis. Furthermore, inhibiting apoptosis by targeting dOmi (Drosophila Htra2/Omi) or DIAP1, or reducing ROS accumulation suppressed retinal degeneration. Our results suggest that i-AAA is essential for removing unfolded proteins and maintaining mitochondrial membrane architecture. Loss of i-AAA leads to the accumulation of oxidative damage and progressive deterioration of membrane integrity, which might contribute to apoptosis upon the release of proapoptotic molecules such as dOmi. Containing ROS level could be a potential strategy to manage mitochondrial AAA protease deficiency.
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Affiliation(s)
- Y Qi
- Laboratory of Molecular Genetics, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - H Liu
- National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - M P Daniels
- Laboratory of Molecular Genetics, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - G Zhang
- National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - H Xu
- Laboratory of Molecular Genetics, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
- Laboratory of Molecular Genetics, National Heart, Lung and Blood Institute, National Institutes of Health, 10 Center Drive, Building 10, 6C212, Bethesda, MD 20892, USA. Tel/Fax: +1 301 594 5940; E-mail:
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17
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Szklarczyk R, Nooteboom M, Osiewacz HD. Control of mitochondrial integrity in ageing and disease. Philos Trans R Soc Lond B Biol Sci 2015; 369:20130439. [PMID: 24864310 DOI: 10.1098/rstb.2013.0439] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Various molecular and cellular pathways are active in eukaryotes to control the quality and integrity of mitochondria. These pathways are involved in keeping a 'healthy' population of this essential organelle during the lifetime of the organism. Quality control (QC) systems counteract processes that lead to organellar dysfunction manifesting as degenerative diseases and ageing. We discuss disease- and ageing-related pathways involved in mitochondrial QC: mtDNA repair and reorganization, regeneration of oxidized amino acids, refolding and degradation of severely damaged proteins, degradation of whole mitochondria by mitophagy and finally programmed cell death. The control of the integrity of mtDNA and regulation of its expression is essential to remodel single proteins as well as mitochondrial complexes that determine mitochondrial functions. The redundancy of components, such as proteases, and the hierarchies of the QC raise questions about crosstalk between systems and their precise regulation. The understanding of the underlying mechanisms on the genomic, proteomic, organellar and cellular levels holds the key for the development of interventions for mitochondrial dysfunctions, degenerative processes, ageing and age-related diseases resulting from impairments of mitochondria.
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Affiliation(s)
- Radek Szklarczyk
- Centre for Molecular and Biomolecular Informatics, Radboud University Medical Centre, 6500 HB Nijmegen, The Netherlands Department of Clinical Genetics, Unit Clinical Genomics, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands
| | - Marco Nooteboom
- Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, 6500 HB Nijmegen, The Netherlands
| | - Heinz D Osiewacz
- Faculty for Biosciences and Cluster of Excellence 'Macromolecular Complexes', Goethe University, Molecular Developmental Biology, 60438 Frankfurt am Main, Germany
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18
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Dong WL, Hou CC, Yang WX. Mitochondrial prohibitin and its ubiquitination during crayfish Procambarus clarkii spermiogenesis. Cell Tissue Res 2014; 359:679-692. [PMID: 25418137 DOI: 10.1007/s00441-014-2044-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 10/16/2014] [Indexed: 12/11/2022]
Abstract
Prohibitin (PHB), an evolutionarily conserved mitochondrial membrane protein, is associated with spermatogenesis and sperm quality control in mammals. It is identified as a substrate of ubiquitin and thus may function via a mitochondrial ubiquitin-proteasome pathway. In this study, we examined the localization of PHB during spermiogenesis of the macrura crustacean Procambarus clarkii. We traced phb mRNA's temporal and spatial expression pattern in spermiogenesis, and found its localization highly coherent with acrosome formation and nuclear shaping, two key events during crustacean spermiogenesis. We further detected the associations of PHB with mitochondria and ubiquitin using immunofluorescent staining. PHB was co-localized with mitochondria through spermiogenesis. PHB as well as mitochondria were co-localized with ubiquitin from the late stage of spermiogenesis, and the co-signals reached their peak in the mature sperm. The results raise the hypothesis that PHB is likely to function in nuclear shaping and acrosome formation in the spermiogenesis of P. clarkii. In addition, it might possess a more profound role in mediating mitochondrial ubiquitination. For the first time this study uncovers the role of PHB in the spermiogenesis of macrura crustacean species.
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Affiliation(s)
- Wei-Lai Dong
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, 866 Yu Hang Tang Road, Hangzhou, 310058, China
| | - Cong-Cong Hou
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, 866 Yu Hang Tang Road, Hangzhou, 310058, China
| | - Wan-Xi Yang
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, 866 Yu Hang Tang Road, Hangzhou, 310058, China.
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19
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The amazing ubiquitin-proteasome system: structural components and implication in aging. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 314:171-237. [PMID: 25619718 DOI: 10.1016/bs.ircmb.2014.09.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Proteome quality control (PQC) is critical for the maintenance of cellular functionality and it is assured by the curating activity of the proteostasis network (PN). PN is constituted of several complex protein machines that under conditions of proteome instability aim to, firstly identify, and then, either rescue or degrade nonnative polypeptides. Central to the PN functionality is the ubiquitin-proteasome system (UPS) which is composed from the ubiquitin-conjugating enzymes and the proteasome; the latter is a sophisticated multi-subunit molecular machine that functions in a bimodal way as it degrades both short-lived ubiquitinated normal proteins and nonfunctional polypeptides. UPS is also involved in PQC of the nucleus, the endoplasmic reticulum and the mitochondria and it also interacts with the other main cellular degradation axis, namely the autophagy-lysosome system. UPS functionality is optimum in the young organism but it is gradually compromised during aging resulting in increasing proteotoxic stress; these effects correlate not only with aging but also with most age-related diseases. Herein, we present a synopsis of the UPS components and of their functional alterations during cellular senescence or in vivo aging. We propose that mild UPS activation in the young organism will, likely, promote antiaging effects and/or suppress age-related diseases.
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20
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The mitochondrial unfolded protein response and increased longevity: cause, consequence, or correlation? Exp Gerontol 2014; 56:142-6. [PMID: 24518875 DOI: 10.1016/j.exger.2014.02.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 01/30/2014] [Accepted: 02/01/2014] [Indexed: 12/31/2022]
Abstract
The mitochondrial unfolded protein response is a conserved pathway that allows mitochondrial chaperones and other factors to be induced in response to mitochondrial dysfunction. Activation of this pathway has been proposed to underlie lifespan extension from knockdown or mutation of several nuclear encoded mitochondrial genes in Caenorhabditis elegans. In some cases, however, induction of the mitochondrial unfolded protein response is associated with a reduction of lifespan in both yeast and C. elegans. It also has yet to be demonstrated that induction of the mitochondrial unfolded protein response is sufficient to increase lifespan in the absence of overt mitochondrial dysfunction. In this perspective, we briefly review the evidence for and against a direct pro-longevity role of the mitochondrial unfolded protein response and suggest important areas of investigation for experimentally addressing this question.
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21
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Clustering of OB-fold domains of the partner protease complexed with trimeric stomatin from Thermococcales. Biochimie 2013; 95:1494-501. [PMID: 23587725 DOI: 10.1016/j.biochi.2013.04.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2012] [Accepted: 04/04/2013] [Indexed: 11/22/2022]
Abstract
The C-terminal soluble domain of stomatin operon partner protein (STOPP) of the hyperthermophilic archaeon Pyrococcus horikoshii has an oligonucleotide binding-fold (OB-fold). STOPP lacks the conserved surface residues necessary for binding to DNA/RNA. A tryptophan (W) residue is conserved instead at the molecular surface. Solvent-accessible W residues are often found at interfaces of protein-protein complexes, which suggested the possibility of self-assembling of STOPP. Protein-protein interactions among the C-terminal soluble domains of STOPP PH1510 (1510-C) were then analyzed by chemical linking and blue native polyacrylamide gel electrophoresis (BN-PAGE) methods. These results suggest that the soluble domains of STOPP could assemble into homo-oligomers. Since hexameric subcomplex I from archaeal proteasome consists of coiled-coil segments and OB-fold domains, molecular modeling of 1510-C was performed using hexameric subcomplex I as a template. Although 1510-C is a comparatively small polypeptide consisting of approximately 60 residues, numerous salt bridges and hydrophobic interactions were observed in the predicted hexamer of 1510-C, suggesting the stability of the homo-oligomeric structure. This oligomeric property of STOPP may be favorable for triplicate proteolysis of the trimer of prokaryotic stomatin.
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Li W, Rao DK, Kaur P. Dual role of the metalloprotease FtsH in biogenesis of the DrrAB drug transporter. J Biol Chem 2013; 288:11854-64. [PMID: 23504316 DOI: 10.1074/jbc.m112.441915] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
This study provides the first direct evidence for the dual role of the metalloprotease FtsH in membrane protein biogenesis. Using the physiological substrate DrrAB, it is shown that FtsH is not only responsible for proteolysis of unassembled DrrB protein but also plays a much broader role in biogenesis of the DrrAB complex. Previous studies showed that the stable expression of DrrB in the membrane depends on simultaneous expression of DrrA. Here we show that DrrB is proteolyzed by FtsH when it is expressed alone. Moreover, DrrA and DrrB proteins expressed together in a temperature-sensitive ftsH mutant strain of Escherichia coli were found to be nonfunctional due to their incorrect assembly. Simultaneous expression of wild-type FtsH in trans resulted in normal doxorubicin efflux. Strikingly, doxorubicin efflux could be restored in mutant cells irrespective of whether FtsH was expressed simultaneously with DrrAB or expressed after these proteins had already accumulated in an inactive conformation, thus providing crucial evidence for the ability of FtsH to refold the misassembled proteins. Complementation experiments also showed that the catalytic AAA domain of FtsH contains a chaperone-like activity, however, unlike wild-type FtsH, it was unable to restore function. Our results therefore show for the first time that FtsH contains the protease as well as refolding functions, and both the AAA and the proteolytic domains of FtsH are required for each of these activities.
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Affiliation(s)
- Wen Li
- Department of Biology, Georgia State University, Atlanta, Georgia 30303, USA
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Abstract
SIGNIFICANCE Lysosomes are acidic organelles containing more than fifty hydrolases that provide for the degradation of intracellular and endocytosed materials by autophagy and heterophagy, respectively. They digest a variety of macromolecules, as well as all organelles, and their integrity is crucial. As a result of the degradation of iron-containing macromolecules (e.g., ferritin and mitochondrial components) or endocytosed erythrocytes (by macrophages), lysosomes can accumulate large amounts of iron. This iron occurs often as Fe(II) due to the acidic and reducing lysosomal environment. Fe(II) is known to catalyze Fenton reactions, yielding extremely reactive hydroxyl radicals that may jeopardize lysosomal membrane integrity during oxidative stress. This results in the release of hydrolases and redox-active iron into the cytosol with ensuing damage or cell death. Lysosomes play key roles not only in apoptosis and necrosis but also in neurodegeneration, aging, and atherosclerosis. RECENT ADVANCES The damaging effect of intralysosomal iron can be hampered by endogenous or exogenous iron chelators that enter the lysosomal compartment by membrane permeation, endocytosis, or autophagy. CRITICAL ISSUES Cellular sensitivity to oxidative stress is enhanced by lysosomal redox-active iron or by lysosomal-targeted copper chelators binding copper (from degradation of copper-containing macromolecules) in redox-active complexes. Probably due to higher copper levels, lysosomes of malignant cells may be specifically sensitized by such chelators. FUTURE DIRECTIONS By increasing lysosomal redox-active iron or exposing cells to lysosomal-targeted copper chelators, it should be possible to enhance the sensitivity of cancer cells to radiation-induced oxidative stress or treatment with cytostatics that induce such stress.
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Affiliation(s)
- Alexei Terman
- Department of Clinical Pathology and Cytology, Karolinska University Hospital in Huddinge, Stockholm, Sweden
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Abstract
This review focuses on organellar AAA/FtsH proteases, whose proteolytic and chaperone-like activity is a crucial component of the protein quality control systems of mitochondrial and chloroplast membranes. We compare the AAA/FtsH proteases from yeast, mammals and plants. The nature of the complexes formed by AAA/FtsH proteases and the current view on their involvement in degradation of non-native organellar proteins or assembly of membrane complexes are discussed. Additional functions of AAA proteases not directly connected with protein quality control found in yeast and mammals but not yet in plants are also described shortly. Following an overview of the molecular functions of the AAA/FtsH proteases we discuss physiological consequences of their inactivation in yeast, mammals and plants. The molecular basis of phenotypes associated with inactivation of the AAA/FtsH proteases is not fully understood yet, with the notable exception of those observed in m-AAA protease-deficient yeast cells, which are caused by impaired maturation of mitochondrial ribosomal protein. Finally, examples of cytosolic events affecting protein quality control in mitochondria and chloroplasts are given. This article is part of a Special Issue entitled: Protein Import and Quality Control in Mitochondria and Plastids.
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Affiliation(s)
- Hanna Janska
- Department of Biotechnology, University of Wroclaw, Przybyszewskiego 63/77, 51-148 Wroclaw, Poland.
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25
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Soubannier V, Rippstein P, Kaufman BA, Shoubridge EA, McBride HM. Reconstitution of mitochondria derived vesicle formation demonstrates selective enrichment of oxidized cargo. PLoS One 2012; 7:e52830. [PMID: 23300790 PMCID: PMC3530470 DOI: 10.1371/journal.pone.0052830] [Citation(s) in RCA: 220] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Accepted: 11/22/2012] [Indexed: 11/18/2022] Open
Abstract
The mechanisms that ensure the removal of damaged mitochondrial proteins and lipids are critical for the health of the cell, and errors in these pathways are implicated in numerous degenerative diseases. We recently uncovered a new pathway for the selective removal of proteins mediated by mitochondrial derived vesicular carriers (MDVs) that transit to the lysosome. However, it was not determined whether these vesicles were selectively enriched for oxidized, or damaged proteins, and the extent to which the complexes of the electron transport chain and the mtDNA-containing nucloids may have been incorporated. In this study, we have developed a cell-free mitochondrial budding reaction in vitro in order to better dissect the pathway. Our data confirm that MDVs are stimulated upon various forms of mitochondrial stress, and the vesicles incorporated quantitative amounts of cargo, whose identity depended upon the nature of the stress. Under the conditions examined, MDVs did not incorporate complexes I and V, nor were any nucleoids present, demonstrating the specificity of cargo incorporation. Stress-induced MDVs are selectively enriched for oxidized proteins, suggesting that conformational changes induced by oxidation may initiate their incorporation into the vesicles. Ultrastructural analyses of MDVs isolated on sucrose flotation gradients revealed the formation of both single and double membranes vesicles of unique densities and uniform diameter. This work provides a framework for a reductionist approach towards a detailed examination of the mechanisms of MDV formation and cargo incorporation, and supports the emerging concept that MDVs are critical contributors to mitochondrial quality control.
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Affiliation(s)
- Vincent Soubannier
- Montreal Neurological Institute, McGill University, Montréal, Québec, Canada
| | - Peter Rippstein
- Lipoproteins and Atherosclerosis Group, University of Ottawa Heart Institute, Ottawa, Ontario, Canada
| | - Brett A. Kaufman
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Eric A. Shoubridge
- Montreal Neurological Institute, McGill University, Montréal, Québec, Canada
| | - Heidi M. McBride
- Montreal Neurological Institute, McGill University, Montréal, Québec, Canada
- * E-mail:
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26
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Federico A, Cardaioli E, Da Pozzo P, Formichi P, Gallus GN, Radi E. Mitochondria, oxidative stress and neurodegeneration. J Neurol Sci 2012; 322:254-62. [PMID: 22669122 DOI: 10.1016/j.jns.2012.05.030] [Citation(s) in RCA: 517] [Impact Index Per Article: 43.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 05/10/2012] [Accepted: 05/12/2012] [Indexed: 02/06/2023]
Abstract
Mitochondria are involved in ATP supply to cells through oxidative phosphorylation (OXPHOS), synthesis of key molecules and response to oxidative stress, as well as in apoptosis. They contain many redox enzymes and naturally occurring inefficiencies of oxidative phosphorylation generate reactive oxygen species (ROS). CNS functions depend heavily on efficient mitochondrial function, since brain tissue has a high energy demand. Mutations in mitochondrial DNA (mtDNA), generation and presence of ROS and environmental factors may contribute to energy failure and lead to neurodegenerative diseases. Many rare metabolic disorders have been associated with mitochondrial dysfunction. More than 300 pathogenic mtDNA mutations involve proteins that regulate OXPHOS and mitochondrial structural integrity, and have also been described in neurodegenerative diseases with autosomal inheritance. Mitochondria may have an important role in ageing-related neurodegenerative disorders like Parkinson's disease (PD), Alzheimer's disease (AD), Huntington's disease (HD) and amyotrophic lateral sclerosis (ALS). In primary mitochondrial and neurodegenerative disorders, there is strong evidence that mitochondrial dysfunction occurs early and has a primary role in pathogenesis. In the present review, we discuss several mitochondrial diseases as models of neurodegeneration.
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Affiliation(s)
- Antonio Federico
- Department of Neurological, Neurosurgical and Behavioural Sciences, Medical School, University of Siena, Italy.
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27
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Yokoyama H, Takizawa N, Kobayashi D, Matsui I, Fujii S. Crystal structure of a membrane stomatin-specific protease in complex with a substrate peptide. Biochemistry 2012; 51:3872-80. [PMID: 22475127 DOI: 10.1021/bi300098k] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Membrane-bound proteases are involved in various regulatory functions. A previous report indicated that the N-terminal region of PH1510p (1510-N) from the hyperthermophilic archaeon Pyrococcus horikoshii is a serine protease with a catalytic Ser-Lys dyad (Ser97 and Lys138) and specifically cleaves the C-terminal hydrophobic region of the p-stomatin PH1511p. In humans, an absence of stomatin is associated with a form of hemolytic anemia known as hereditary stomatocytosis. Here, the crystal structure of 1510-N K138A in complex with a peptide substrate was determined at 2.25 Å resolution. In the structure, a 1510-N dimer binds to one peptide. The six central residues (VIVLML) of the peptide are hydrophobic and in a pseudopalindromic structure and therefore favorably fit into the hydrophobic active tunnel of the 1510-N dimer, although 1510-N degrades the substrate at only one point. A comparison with unliganded 1510-N K138A revealed that the binding of the substrate causes a large rotational and translational displacement between protomers and produces a tunnel suitable for binding the peptide. When the peptide binds, the flexible L2 loop of one protomer forms β-strands, whereas that of the other protomer remains in a loop form, indicating that one protomer binds to the peptide more tightly than the other protomer. The Ala138 residues of the two protomers are located very close together (the distance between the two Cβ atoms is 3.6 Å). Thus, in wild-type 1510-N, the close positioning of the catalytic Ser97 and Lys138 residues may be induced by electrostatic repulsion of the two Lys138 side chains of the protomers.
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Affiliation(s)
- Hideshi Yokoyama
- School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan.
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28
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Protein quality control in organelles - AAA/FtsH story. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:381-7. [PMID: 22498346 DOI: 10.1016/j.bbamcr.2012.03.016] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Revised: 03/26/2012] [Accepted: 03/27/2012] [Indexed: 11/23/2022]
Abstract
This review focuses on organellar AAA/FtsH proteases, whose proteolytic and chaperone-like activity is a crucial component of the protein quality control systems of mitochondrial and chloroplast membranes. We compare the AAA/FtsH proteases from yeast, mammals and plants. The nature of the complexes formed by AAA/FtsH proteases and the current view on their involvement in degradation of non-native organellar proteins or assembly of membrane complexes are discussed. Additional functions of AAA proteases not directly connected with protein quality control found in yeast and mammals but not yet in plants are also described shortly. Following an overview of the molecular functions of the AAA/FtsH proteases we discuss physiological consequences of their inactivation in yeast, mammals and plants. The molecular basis of phenotypes associated with inactivation of the AAA/FtsH proteases is not fully understood yet, with the notable exception of those observed in m-AAA protease-deficient yeast cells, which are caused by impaired maturation of mitochondrial ribosomal protein. Finally, examples of cytosolic events affecting protein quality control in mitochondria and chloroplasts are given. This article is part of a Special Issue entitled: Protein Import and Quality Control in Mitochondria and Plastids.
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29
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Metalloprotease-mediated OPA1 processing is modulated by the mitochondrial membrane potential. Biol Cell 2012; 100:315-25. [DOI: 10.1042/bc20070110] [Citation(s) in RCA: 129] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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30
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Wilkens V, Kohl W, Busch K. Restricted diffusion of OXPHOS complexes in dynamic mitochondria delays their exchange between cristae and engenders a transitory mosaic distribution. J Cell Sci 2012; 126:103-16. [DOI: 10.1242/jcs.108852] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Mitochondria are involved in cellular energy supply, signaling and apoptosis. Their ability to fuse and divide provides functional and morphological flexibility and is a key feature in mitochondrial quality maintenance. To study the impact of mitochondrial fusion/fission on the reorganization of inner membrane proteins, OXPHOS complexes in mitochondria of different HeLa cells were tagged with fluorescent proteins (GFP and RFP-HA, respectively), and cells were fused by PEG treatment. Redistribution of the tagged OXPHOS complexes was then followed by means of immuno electron microscopy, two color superresolution fluorescence microscopy and single molecule tracking. In contrast to outer membrane and matrix proteins, which mix fast and homogeneously upon mitochondrial fusion, the mixing of inner membrane proteins was decelerated. Our data suggest that in principle (i) with respect to their composition cristae are preserved during fusion of mitochondria and (ii) cristae with mixed OXPHOS complexes are only slowly and successively formed by restricted diffusion of inner membrane proteins into existing cristae. The resulting transitory mosaic appearance of the inner mitochondrial membrane in terms of composition illuminates mitochondrial heterogeneity and potentially is linked to local differences in function and membrane potential.
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31
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Venkatesh S, Lee J, Singh K, Lee I, Suzuki CK. Multitasking in the mitochondrion by the ATP-dependent Lon protease. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1823:56-66. [PMID: 22119779 DOI: 10.1016/j.bbamcr.2011.11.003] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 10/30/2011] [Accepted: 11/06/2011] [Indexed: 01/13/2023]
Abstract
The AAA(+) Lon protease is a soluble single-ringed homo-oligomer, which represents the most streamlined operational unit mediating ATP-dependent proteolysis. Despite its simplicity, the architecture of Lon proteases exhibits a species-specific diversity. Homology modeling provides insights into the structural features that distinguish bacterial and human Lon proteases as hexameric complexes from yeast Lon, which is uniquely heptameric. The best-understood functions of mitochondrial Lon are linked to maintaining proteostasis under normal metabolic conditions, and preventing proteotoxicity during environmental and cellular stress. An intriguing property of human Lon is its specific binding to G-quadruplex DNA, and its association with the mitochondrial genome in cultured cells. A fraction of Lon preferentially binds to the control region of mitochondrial DNA where transcription and replication are initiated. Here, we present an overview of the diverse functions of mitochondrial Lon, as well as speculative perspectives on its role in protein and mtDNA quality control.
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Affiliation(s)
- Sundararajan Venkatesh
- Department of Biochemistry and Molecular Biology, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, 185 South Orange Avenue, MSB E-633, Newark, New Jersey 07103 USA
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32
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Sánchez-Ferrero E, Coto E, Corao AI, Díaz M, Gámez J, Esteban J, Gonzalo JF, Pascual-Pascual SI, De Munaín AL, Morís G, Infante J, Del Castillo E, Márquez C, Álvarez V. Mitochondrial DNA polymorphisms/haplogroups in hereditary spastic paraplegia. J Neurol 2011; 259:246-50. [DOI: 10.1007/s00415-011-6155-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Accepted: 06/20/2011] [Indexed: 12/29/2022]
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Narendra DP, Youle RJ. Targeting mitochondrial dysfunction: role for PINK1 and Parkin in mitochondrial quality control. Antioxid Redox Signal 2011; 14:1929-38. [PMID: 21194381 PMCID: PMC3078490 DOI: 10.1089/ars.2010.3799] [Citation(s) in RCA: 276] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Mitochondria, which convert energy for the cell, accumulate damage with age, and the resulting mitochondrial dysfunction has been linked to the development of degenerative diseases and aging. To curb the accumulation of damaged mitochondria, the cell has elaborated a number of mitochondrial quality control processes. We describe recent work suggesting that Parkin and PTEN-induced putative kinase 1 (PINK1), two gene products linked to familial forms of parkinsonism, may constitute one of the cell's mitochondrial quality control pathways-identifying impaired mitochondria and selectively trimming them from the mitochondrial network by mitophagy. In particular, we discuss the regulation of PINK1 protein expression and Parkin localization by the bioenergetic status of individual mitochondria; the mechanism by which PINK1 recruits Parkin to the outer mitochondrial membrane; and Parkin's promotion of mitophagy through its ubiquitination of outer mitochondrial membrane proteins. This recent work suggests that Parkin and PINK1 may be among the first mammalian proteins identified with a direct role in regulating mitophagy, and implicate a failure of mitophagy in the pathogenesis of Parkinson's disease.
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Affiliation(s)
- Derek P Narendra
- Biochemistry Section, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA
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34
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Miyamoto Y, Kitamura N, Nakamura Y, Futamura M, Miyamoto T, Yoshida M, Ono M, Ichinose S, Arakawa H. Possible existence of lysosome-like organella within mitochondria and its role in mitochondrial quality control. PLoS One 2011; 6:e16054. [PMID: 21264221 PMCID: PMC3022026 DOI: 10.1371/journal.pone.0016054] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Accepted: 12/04/2010] [Indexed: 01/07/2023] Open
Abstract
The accumulation of unhealthy mitochondria results in mitochondrial dysfunction, which has been implicated in aging, cancer, and a variety of degenerative diseases. However, the mechanism by which mitochondrial quality is regulated remains unclear. Here, we show that Mieap, a novel p53-inducible protein, induces intramitochondrial lysosome-like organella that plays a critical role in mitochondrial quality control. Mieap expression is directly regulated by p53 and is frequently lost in human cancer as result of DNA methylation. Mieap dramatically induces the accumulation of lysosomal proteins within mitochondria and mitochondrial acidic condition without destroying the mitochondrial structure (designated MALM, for Mieap-induced accumulation of lysosome-like organelles within mitochondria) in response to mitochondrial damage. MALM was not related to canonical autophagy. MALM is involved in the degradation of oxidized mitochondrial proteins, leading to increased ATP synthesis and decreased reactive oxygen species generation. These results suggest that Mieap induces intramitochondrial lysosome-like organella that plays a critical role in mitochondrial quality control by eliminating oxidized mitochondrial proteins. Cancer cells might accumulate unhealthy mitochondria due to p53 mutations and/or Mieap methylation, representing a potential cause of the Warburg effect.
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Affiliation(s)
- Yuji Miyamoto
- Cancer Medicine and Biophysics Division, National Cancer Center Research Institute, Tokyo, Japan
| | - Noriaki Kitamura
- Cancer Medicine and Biophysics Division, National Cancer Center Research Institute, Tokyo, Japan
| | - Yasuyuki Nakamura
- Cancer Medicine and Biophysics Division, National Cancer Center Research Institute, Tokyo, Japan
| | - Manabu Futamura
- Cancer Medicine and Biophysics Division, National Cancer Center Research Institute, Tokyo, Japan
| | - Takafumi Miyamoto
- Cancer Medicine and Biophysics Division, National Cancer Center Research Institute, Tokyo, Japan
| | - Masaki Yoshida
- Cancer Medicine and Biophysics Division, National Cancer Center Research Institute, Tokyo, Japan
| | - Masaya Ono
- Chemotherapy Division, National Cancer Center Research Institute, Tokyo, Japan
| | - Shizuko Ichinose
- Instrumental Analysis Research Center, Tokyo Medical and Dental University, Tokyo, Japan
| | - Hirofumi Arakawa
- Cancer Medicine and Biophysics Division, National Cancer Center Research Institute, Tokyo, Japan
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35
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Abstract
Mitochondrial bioenergetic function is a key to cell life and death. Cells need energy not only to support their vital functions but also to die gracefully. Execution of an apoptotic program includes energy-dependent steps, including kinase signaling, formation of the apoptosome, and effector caspase activation. Under conditions of bioenergetic collapse, cells are diverted toward necrotic demise. Mitochondrial outer membrane permeabilization (MOMP) is a decisive event in the execution of apoptosis. It is also causally linked to a decline in bioenergetic function via different mechanisms, not merely due to cytochrome c dispersion. MOMP-induced bioenergetic deficiency is usually irreversible and commits cells to die, even when caspases are inactive. Here, we discuss the mechanisms by which MOMP impacts bioenergetics in different cell death paradigms.
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Affiliation(s)
- Yulia Kushnareva
- La Jolla Institute for Allergy and Immunology, La Jolla, California 92037, USA
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36
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Bender T, Leidhold C, Ruppert T, Franken S, Voos W. The role of protein quality control in mitochondrial protein homeostasis under oxidative stress. Proteomics 2010; 10:1426-43. [PMID: 20186747 DOI: 10.1002/pmic.200800619] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Mitochondria contribute significantly to the cellular production of ROS. The deleterious effects of increased ROS levels have been implicated in a wide variety of pathological reactions. Apart from a direct detoxification of ROS molecules, protein quality control mechanisms are thought to protect protein functions in the presence of elevated ROS levels. The reactivities of molecular chaperones and proteases remove damaged polypeptides, maintaining enzyme activities, thereby contributing to cellular survival both under normal and stress conditions. We characterized the impact of oxidative stress on mitochondrial protein homeostasis by performing a proteomic analysis of isolated yeast mitochondria, determining the changes in protein abundance after ROS treatments. We identified a set of mitochondrial proteins as substrates of ROS-dependent proteolysis. Enzymes containing oxidation-sensitive prosthetic groups like iron/sulfur clusters represented major targets of stress-dependent degradation. We found that several proteins involved in ROS detoxification were also affected. We identified the ATP-dependent protease Pim1/LON as a major factor in the degradation of ROS-modified soluble polypeptides localized in the matrix compartment. As Pim1/LON expression was induced significantly under ROS treatment, we propose that this protease system performs a crucial protective function under oxidative stress conditions.
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Affiliation(s)
- Tom Bender
- Institut für Biochemie und Molekularbiologie, Universität Bonn, Bonn, Germany
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37
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Drastichova Z, Bourova L, Hejnova L, Jedelsky P, Svoboda P, Novotny J. Protein alterations induced by long-term agonist treatment of HEK293 cells expressing thyrotropin-releasing hormone receptor and G11alpha protein. J Cell Biochem 2010; 109:255-64. [PMID: 19911373 DOI: 10.1002/jcb.22409] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This study aimed to determine whether sustained stimulation with thyrotropin-releasing hormone (TRH), a peptide with important physiological functions, can possibly affect expression of plasma membrane proteins in HEK293 cells expressing high levels of TRH receptor and G(11)alpha protein. Our previous experiments using silver-stained two-dimensional polyacrylamide gel electrophoretograms did not reveal any significant changes in an overall composition of membrane microdomain proteins after long-term treatment with TRH of these cells (Matousek et al. 2005 Cell Biochem Biophys 42: 21-40). Here we used a purified plasma membrane fraction prepared by Percoll gradient centrifugation and proteins resolved by 2D electrophoresis were stained with SYPRO Ruby gel stain. The high enrichment in plasma membrane proteins of this preparation was confirmed by a multifold increase in the number of TRH receptors and agonist stimulated G-protein activity, compared to postnuclear supernatant. By a combination of these approaches we were able to determine a number of clearly discernible protein changes in the plasma membrane-enriched fraction isolated from cells treated with TRH (1 x 10(-5) M, 16 h): 4 proteins disappeared, the level of 18 proteins decreased and the level of 39 proteins increased. Our concomitant immunochemical determinations also indicated a clear down-regulation of G(q/11)alpha proteins in preparations from hormone-treated cells. In parallel, we observed decrease in caspase 3 and alterations in some other apoptotic marker proteins, which were in line with the presumed antiapoptotic effect of TRH.
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Affiliation(s)
- Zdenka Drastichova
- Faculty of Science, Department of Physiology, Charles University, Vinicna 7, Prague, Czech Republic
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38
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Radivojac P, Vacic V, Haynes C, Cocklin RR, Mohan A, Heyen JW, Goebl MG, Iakoucheva LM. Identification, analysis, and prediction of protein ubiquitination sites. Proteins 2010; 78:365-80. [PMID: 19722269 DOI: 10.1002/prot.22555] [Citation(s) in RCA: 422] [Impact Index Per Article: 30.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Ubiquitination plays an important role in many cellular processes and is implicated in many diseases. Experimental identification of ubiquitination sites is challenging due to rapid turnover of ubiquitinated proteins and the large size of the ubiquitin modifier. We identified 141 new ubiquitination sites using a combination of liquid chromatography, mass spectrometry, and mutant yeast strains. Investigation of the sequence biases and structural preferences around known ubiquitination sites indicated that their properties were similar to those of intrinsically disordered protein regions. Using a combined set of new and previously known ubiquitination sites, we developed a random forest predictor of ubiquitination sites, UbPred. The class-balanced accuracy of UbPred reached 72%, with the area under the ROC curve at 80%. The application of UbPred showed that high confidence Rsp5 ubiquitin ligase substrates and proteins with very short half-lives were significantly enriched in the number of predicted ubiquitination sites. Proteome-wide prediction of ubiquitination sites in Saccharomyces cerevisiae indicated that highly ubiquitinated substrates were prevalent among transcription/enzyme regulators and proteins involved in cell cycle control. In the human proteome, cytoskeletal, cell cycle, regulatory, and cancer-associated proteins display higher extent of ubiquitination than proteins from other functional categories. We show that gain and loss of predicted ubiquitination sites may likely represent a molecular mechanism behind a number of disease-associatedmutations. UbPred is available at http://www.ubpred.org.
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Affiliation(s)
- Predrag Radivojac
- School of Informatics, Indiana University, Bloomington, Indiana 47408, USA
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39
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Piechota J, Kolodziejczak M, Juszczak I, Sakamoto W, Janska H. Identification and characterization of high molecular weight complexes formed by matrix AAA proteases and prohibitins in mitochondria of Arabidopsis thaliana. J Biol Chem 2010; 285:12512-21. [PMID: 20172857 DOI: 10.1074/jbc.m109.063644] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We identify and characterize two matrix (m)-AAA proteases (AtFtsH3 and AtFtsH10) present in the mitochondria of Arabidopsis thaliana. AtFtsH3 is the predominant protease in leaves of wild type plants. Both proteases assemble with prohibitins (PHBs) into high molecular weight complexes (approximately 2 MDa), similarly to their yeast counterparts. A smaller PHB complex (approximately 1 MDa), without the m-AAA proteases, was also detected. Unlike in yeast, stable prohibitin-independent high molecular weight assemblies of m-AAA proteases could not be identified in A. thaliana. AtFtsH3 and AtFtsH10 form at least two types of m-AAA-PHB complexes in wild type plants. The one type contains PHBs and AtFtsH3, and the second one is composed of PHBs and both AtFtsH3 and AtFtsH10. Complexes composed of PHBs and AtFtsH10 were found in an Arabidopsis mutant lacking AtFtsH3 (ftsh3). Thus, both AtFtsH3 and AtFtsH10 may form hetero- and homo-oligomeric complexes with prohibitins. The increased level of AtFtsH10 observed in ftsh3 suggests that functions of the homo- and hetero-oligomeric complexes containing AtFtsH3 can be at least partially substituted by AtFtsH10 homo-oligomers. The steady-state level of the AtFtsH10 transcripts did not change in ftsh3 compared with wild type plants, but we found that almost twice more of the AtFtsH10 transcripts were associated with polysomes in ftsh3. Based on this result, we assume that the AtFtsH10 protein is synthesized at a higher rate in the ftsh3 mutant. Our results provide the first data on the composition of m-AAA and PHB complexes in plant mitochondria and suggest that the abundance of m-AAA proteases is regulated not only at the transcriptional but also at the translational level.
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Affiliation(s)
- Janusz Piechota
- Department of Biotechnology, University of Wrocław, 51-148 Wrocław, Poland
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40
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Bayot A, Gareil M, Rogowska-Wrzesinska A, Roepstorff P, Friguet B, Bulteau AL. Identification of novel oxidized protein substrates and physiological partners of the mitochondrial ATP-dependent Lon-like protease Pim1. J Biol Chem 2010; 285:11445-57. [PMID: 20150421 DOI: 10.1074/jbc.m109.065425] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
ATP-dependent proteases are currently emerging as key regulators of mitochondrial functions. Among these proteolytic systems, Pim1, a Lon-like serine protease in Saccharomyces cerevisiae, is involved in the control of selective protein turnover in the mitochondrial matrix. In the absence of Pim1, yeast cells have been shown to accumulate electron-dense inclusion bodies in the matrix space, to lose integrity of mitochondrial genome, and to be respiration-deficient. Because of the severity of phenotypes associated with the depletion of Pim1, this protease appears to be an essential component of the protein quality control machinery in mitochondria and to exert crucial functions during the biogenesis of this organelle. Nevertheless, its physiological substrates and partners are not fully characterized. Therefore, we used the combination of different proteomic techniques to assess the nature of oxidized protein substrates and physiological partners of Pim1 protease under non-repressing growth conditions. The results presented here supply evidence that Pim1-mediated proteolysis is required for elimination of oxidatively damaged proteins in mitochondria.
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Affiliation(s)
- Aurélien Bayot
- Laboratoire de Biologie Cellulaire du Vieillissement, UR4, Vieillissement, Stress et Inflammation, Université Pierre et Marie Curie-Paris 6, Case Courrier 256, Batiment A, 5ème Etage, 7 Quai Saint Bernard, 75252 Paris Cedex 05, France
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41
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The influence of the acyl chain composition of cardiolipin on the stability of mitochondrial complexes; An unexpected effect of cardiolipin in α-ketoglutarate dehydrogenase and prohibitin complexes. J Proteomics 2010; 73:806-14. [DOI: 10.1016/j.jprot.2009.11.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Revised: 11/02/2009] [Accepted: 11/17/2009] [Indexed: 02/06/2023]
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42
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Hill RB, Pellegrini L. The PARL family of mitochondrial rhomboid proteases. Semin Cell Dev Biol 2010; 21:582-92. [PMID: 20045481 DOI: 10.1016/j.semcdb.2009.12.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Revised: 12/10/2009] [Accepted: 12/18/2009] [Indexed: 10/20/2022]
Abstract
Rhomboids are an ancient and conserved family of intramembrane-cleaving proteases, a small group of proteolytic enzymes capable of hydrolyzing a peptide bond within a transmembrane helix that anchors a substrate protein to the membrane. Mitochondrial rhomboids evolved in eukaryotes to coordinate a critical aspect of cell biology, the regulation of mitochondrial membranes dynamics. This function appears to have required the emergence of a structural feature that is unique among all other rhomboids: an additional transmembrane helix (TMH) positioned at the N-terminus of six TMHs that form the core proteolytic domain of all prokaryotic and eukaryotic rhomboids. This "1+6" structure, which is shared only among mitochondrial rhomboids, defines a subfamily of rhomboids with the prototypical family member being mammalian Parl. Here, we present the findings that in 11 years have elevated mitochondrial rhomboids as the gatekeepers of mitochondrial dynamics and apoptosis; further, we discuss the aspects of their biology that are bound to introduce new paradigm shifts in our understanding of how the organelle uses this unique type of protease to govern stress, signaling to the nucleus, and other key mitochondrial activities in health and disease.
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Affiliation(s)
- R Blake Hill
- Department of Biology, Johns Hopkins University, Baltimore, MD, USA.
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Lartigue L, Kushnareva Y, Seong Y, Lin H, Faustin B, Newmeyer DD. Caspase-independent mitochondrial cell death results from loss of respiration, not cytotoxic protein release. Mol Biol Cell 2009; 20:4871-84. [PMID: 19793916 PMCID: PMC2785731 DOI: 10.1091/mbc.e09-07-0649] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Revised: 09/17/2009] [Accepted: 09/23/2009] [Indexed: 01/29/2023] Open
Abstract
In apoptosis, mitochondrial outer membrane permeabilization (MOMP) triggers caspase-dependent death. However, cells undergo clonogenic death even if caspases are blocked. One proposed mechanism involved the release of cytotoxic proteins (e.g., AIF and endoG) from mitochondria. To initiate MOMP directly without side effects, we created a tamoxifen-switchable BimS fusion protein. Surprisingly, even after MOMP, caspase-inhibited cells replicated DNA and divided for approximately 48 h before undergoing proliferation arrest. AIF and endoG remained in mitochondria. However, cells gradually lost mitochondrial membrane potential and ATP content, and DNA synthesis slowed to a halt by 72 h. These defects resulted from a partial loss of respiratory function, occurring 4-8 h after MOMP, that was not merely due to dispersion of cytochrome c. In particular, Complex I activity was completely lost, and Complex IV activity was reduced by approximately 70%, whereas Complex II was unaffected. Later, cells exhibited a more profound loss of mitochondrial protein constituents. Thus, under caspase inhibition, MOMP-induced clonogenic death results from a progressive loss of mitochondrial function, rather than the release of cytotoxic proteins from mitochondria.
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Affiliation(s)
- Lydia Lartigue
- *La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037; and
| | - Yulia Kushnareva
- *La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037; and
| | - Youngmo Seong
- *La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037; and
| | - Helen Lin
- *La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037; and
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Agnetti G, Kaludercic N, Kane LA, Elliott ST, Guo Y, Chakir K, Samantapudi D, Paolocci N, Tomaselli GF, Kass DA, Van Eyk JE. Modulation of mitochondrial proteome and improved mitochondrial function by biventricular pacing of dyssynchronous failing hearts. ACTA ACUST UNITED AC 2009; 3:78-87. [PMID: 20160199 DOI: 10.1161/circgenetics.109.871236] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Cardiac resynchronization therapy (CRT) improves chamber mechanoenergetics and morbidity and mortality of patients manifesting heart failure with ventricular dyssynchrony; however, little is known about the molecular changes underlying CRT benefits. We hypothesized that mitochondria may play an important role because of their involvement in energy production. METHODS AND RESULTS Mitochondria isolated from the left ventricle in a canine model of dyssynchronous or resynchronized (CRT) heart failure were analyzed by a classical, gel-based, proteomic approach. Two-dimensional gel electrophoresis revealed that 31 mitochondrial proteins where changed when controlling the false discovery rate at 30%. Key enzymes in anaplerotic pathways, such as pyruvate carboxylation and branched-chain amino acid oxidation, were increased. These concerted changes, along with others, suggested that CRT may increase the pool of Krebs cycle intermediates and fuel oxidative phosphorylation. Nearly 50% of observed changes pertained to subunits of the respiratory chain. ATP synthase-beta subunit of complex V was less degraded, and its phosphorylation modulated by CRT was associated with increased formation (2-fold, P=0.004) and specific activity (+20%, P=0.05) of the mature complex. The importance of these modifications was supported by coordinated changes in mitochondrial chaperones and proteases. CRT increased the mitochondrial respiratory control index with tightened coupling when isolated mitochondria were reexposed to substrates for both complex I (glutamate and malate) and complex II (succinate), an effect likely related to ATP synthase subunit modifications and complex quantity and activity. CONCLUSIONS CRT potently affects both the mitochondrial proteome and the performance associated with improved cardiac function.
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Affiliation(s)
- Giulio Agnetti
- Johns Hopkins Bayview Proteomics Center, Baltimore, MD 21224, USA
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Eick M, Stöhr C. Proteolysis at the plasma membrane of tobacco roots: biochemical evidence and possible roles. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2009; 47:1003-8. [PMID: 19651520 DOI: 10.1016/j.plaphy.2009.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2009] [Revised: 07/09/2009] [Accepted: 07/20/2009] [Indexed: 05/28/2023]
Abstract
Plasma membrane-associated proteases (pm-proteases) exist principally in roots of Nicotiana tabacum cv. Samsun, whereas in plasma membrane (pm) vesicles prepared from leaves, protease activity was at the detection limit. Biochemical characterisation revealed a high diversity of particular hydrophobic pm-proteases indicating multiple functions in root tissue. One proportion of chromatographically separated proteases was split up by non-reducing SDS-PAGE in 8-12 single polypeptides, dependent on plant nitrogen nutrition. The active polypeptides could be grouped in those that were (i) inhibited, (ii) stimulated and (iii) independent of bivalent cations. Although, the total specific protease activity of various pm vesicles was almost identical, the composition and activity of individual polypeptides was dependent on nitrogen supply of the plants. Particularly, nitrogen deficiency stimulated the activity of high molecular mass proteases (125 kDa-97 kDa), whereas sufficient nitrate supply enhanced proteolytic activity of 90 kDa, 83 kDa and 65 kDa polypeptides. Endogenous proteolysis within pm vesicles suggested that at least partly protease substrates are localised within the same membrane. A comparison of polypeptides originated from proteolysis of pm vesicles and those exudated by roots into the external medium points to a role of root pm-proteases in the specific release of polypeptides into the rhizosphere.
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Affiliation(s)
- Manuela Eick
- University Greifswald, Institute of Botany and Landscape Ecology, Grimmer Strasse 88, D-17487 Greifswald, Germany
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Bos DH, Mayfield C, Minchella DJ. Analysis of regulatory protease sequences identified through bioinformatic data mining of the Schistosoma mansoni genome. BMC Genomics 2009; 10:488. [PMID: 19845954 PMCID: PMC2772863 DOI: 10.1186/1471-2164-10-488] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2009] [Accepted: 10/21/2009] [Indexed: 11/20/2022] Open
Abstract
Background New chemotherapeutic agents against Schistosoma mansoni, an etiological agent of human schistosomiasis, are a priority due to the emerging drug resistance and the inability of current drug treatments to prevent reinfection. Proteases have been under scrutiny as targets of immunological or chemotherapeutic anti-Schistosoma agents because of their vital role in many stages of the parasitic life cycle. Function has been established for only a handful of identified S. mansoni proteases, and the vast majority of these are the digestive proteases; very few of the conserved classes of regulatory proteases have been identified from Schistosoma species, despite their vital role in numerous cellular processes. To that end, we identified protease protein coding genes from the S. mansoni genome project and EST library. Results We identified 255 protease sequences from five catalytic classes using predicted proteins of the S. mansoni genome. The vast majority of these show significant similarity to proteins in KEGG and the Conserved Domain Database. Proteases include calpains, caspases, cytosolic and mitochondrial signal peptidases, proteases that interact with ubiquitin and ubiquitin-like molecules, and proteases that perform regulated intramembrane proteolysis. Comparative analysis of classes of important regulatory proteases find conserved active site domains, and where appropriate, signal peptides and transmembrane helices. Phylogenetic analysis provides support for inferring functional divergence among regulatory aspartic, cysteine, and serine proteases. Conclusion Numerous proteases are identified for the first time in S. mansoni. We characterized important regulatory proteases and focus analysis on these proteases to complement the growing knowledge base of digestive proteases. This work provides a foundation for expanding knowledge of proteases in Schistosoma species and examining their diverse function and potential as targets for new chemotherapies.
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Affiliation(s)
- David H Bos
- Department of Biological Sciences, Purdue University, 915 W State St, West Lafayette, IN 47907, USA.
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Rajawat YS, Hilioti Z, Bossis I. Aging: central role for autophagy and the lysosomal degradative system. Ageing Res Rev 2009; 8:199-213. [PMID: 19427410 DOI: 10.1016/j.arr.2009.05.001] [Citation(s) in RCA: 172] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Revised: 05/01/2009] [Accepted: 05/01/2009] [Indexed: 12/19/2022]
Abstract
The lysosomal network is the major intracellular proteolytic system accounting for more than 98% of long-lived bulk protein degradation and recycling particularly in tissues such as liver and muscles. Lysosomes are the final destination of intracellular damaged structures, identified and sequestered by the processes of macroautophagy and chaperone-mediated autophagy (CMA). In the process of macroautophagy, long-lived proteins and other macromolecular aggregates and damaged intracellular organelles are first engulfed by autophagosomes. Autophagosomes themselves have limited degrading capacity and rely on fusion with lysosomes. Unlike macroautophagy, CMA does not require intermediate vesicle formation and the cytosolic proteins recognized by this pathway are directly translocated to the lysosomal membrane. Aging is a universal phenomenon characterized by progressive deterioration of cells and organs due to accumulation of macromolecular and organelle damage. The continuous removal of worn-out components and replacement with newly synthesized ones ensures cellular homeostasis and delays the aging process. Growing evidence indicate that the rate of autophagosome formation and maturation and the efficiency of autophagosome/lysosome fusion decline with age. In addition, a progressive increase in intralysosomal concentration of free radicals and the age pigment lipofuscin further diminish the efficiency of lysosomal protein degradation. Therefore, integrity of the autophagosomal-lysosomal network appears to be critical in the progression of aging. Discovery of the genes involved in the process of autophagy has provided insight into the various molecular pathways that may be involved in aging and senescence. In this review, we discuss the cellular and molecular mechanisms involved in autophagy and the role of autophagosome/lysosome network in the aging process.
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Affiliation(s)
- Yogendra S Rajawat
- University of Maryland, Department of Veterinary Medicine, College Park, MD 20742, United States
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Mathieu JM, Schloendorn J, Rittmann BE, Alvarez PJJ. Medical bioremediation of age-related diseases. Microb Cell Fact 2009; 8:21. [PMID: 19358742 PMCID: PMC2674406 DOI: 10.1186/1475-2859-8-21] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Accepted: 04/09/2009] [Indexed: 12/12/2022] Open
Abstract
Catabolic insufficiency in humans leads to the gradual accumulation of a number of pathogenic compounds associated with age-related diseases, including atherosclerosis, Alzheimer's disease, and macular degeneration. Removal of these compounds is a widely researched therapeutic option, but the use of antibodies and endogenous human enzymes has failed to produce effective treatments, and may pose risks to cellular homeostasis. Another alternative is "medical bioremediation," the use of microbial enzymes to augment missing catabolic functions. The microbial genetic diversity in most natural environments provides a resource that can be mined for enzymes capable of degrading just about any energy-rich organic compound. This review discusses targets for biodegradation, the identification of candidate microbial enzymes, and enzyme-delivery methods.
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Affiliation(s)
- Jacques M Mathieu
- Dept. of Civil and Environmental Engineering, Rice University, Houston, TX, USA
| | - John Schloendorn
- Dept. of Civil and Environmental Engineering, Arizona State University, Tempe, AZ, USA
| | - Bruce E Rittmann
- Dept. of Civil and Environmental Engineering, Arizona State University, Tempe, AZ, USA
| | - Pedro JJ Alvarez
- Dept. of Civil and Environmental Engineering, Rice University, Houston, TX, USA
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Abstract
Mitochondrial function degenerates with ageing and in ageing-related neuromuscular degenerative diseases, causing physiological decline of the cell. Factors that can delay the degenerative process are actively sought after. Here, we show that reduced cytosolic protein synthesis is a robust cellular strategy that suppresses ageing-related mitochondrial degeneration. We modelled autosomal dominant progressive external ophthalmoplegia (adPEO), an adult- or later-onset degenerative disease, by introducing the A128P mutation into the adenine nucleotide translocase Aac2p of Saccharomyces cerevisiae. The aac2(A128P) allele dominantly induces ageing-dependent mitochondrial degeneration and phenotypically tractable degenerative cell death, independently of its ADP/ATP exchange activity. Mitochondrial degeneration was suppressed by lifespan-extending nutritional interventions and by eight longevity mutations, which are all known to reduce cytosolic protein synthesis. These longevity interventions also independently suppressed ageing-related mitochondrial degeneration in the pro-ageing prohibitin mutants. The aac2(A128P) mutant has reduced mitochondrial membrane potential (delta psi(m)) and is synthetically lethal to low delta psi(m) conditions, including the loss of prohibitin. Mitochondrial degeneration was accelerated by defects in protein turnover on the inner membrane and was suppressed by cycloheximide, a specific inhibitor of cytosolic ribosomes. Reduced cytosolic protein synthesis suppressed membrane depolarization and defects in mitochondrial gene expression in aac(A128P) cells. Our finding thus establishes a link between protein homeostasis (proteostasis), cellular bioenergetics and mitochondrial maintenance during ageing.
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Alterations in oligodendrocyte proteins, calcium homeostasis and new potential markers in schizophrenia anterior temporal lobe are revealed by shotgun proteome analysis. J Neural Transm (Vienna) 2008; 116:275-89. [DOI: 10.1007/s00702-008-0156-y] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2008] [Accepted: 10/29/2008] [Indexed: 12/15/2022]
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