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Li HL, Go S, Chang JC, Verhoeven A, Elferink RO. Soluble adenylyl cyclase, the cell-autonomous member of the family. Biochim Biophys Acta Mol Basis Dis 2024; 1870:166936. [PMID: 37951509 DOI: 10.1016/j.bbadis.2023.166936] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/12/2023] [Accepted: 10/24/2023] [Indexed: 11/14/2023]
Abstract
Soluble adenylyl cyclase (sAC) is the evolutionarily most ancient of a set of 10 adenylyl cyclases (Adcys). While Adcy1 to Adcy9 are cAMP-producing enzymes that are activated by G-protein coupled receptors (GPCRs), Adcy10 (sAC) is an intracellular adenylyl cyclase. sAC plays a pivotal role in numerous cellular processes, ranging from basic physiological functions to complex signaling cascades. As a distinct member of the adenylyl cyclase family, sAC is not activated by GPCRs and stands apart due to its unique characteristics, regulation, and localization within cells. This minireview aims to honour Ulli Brandt, the outgoing Executive Editor of our journal, Biochimica Biophysica Acta (BBA), and longstanding Executive Editor of the BBA section Bioenergetics. We will therefore focus this review on bioenergetic aspects of sAC and, in addition, review some important recent general developments in the field of research on sAC.
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Affiliation(s)
- Hang Lam Li
- Tytgat Institute for Liver and Intestinal Research, Research Institute AGEM, Amsterdam UMC, the Netherlands
| | - Simei Go
- Tytgat Institute for Liver and Intestinal Research, Research Institute AGEM, Amsterdam UMC, the Netherlands
| | - Jung-Chin Chang
- Tytgat Institute for Liver and Intestinal Research, Research Institute AGEM, Amsterdam UMC, the Netherlands
| | - Arthur Verhoeven
- Tytgat Institute for Liver and Intestinal Research, Research Institute AGEM, Amsterdam UMC, the Netherlands
| | - Ronald Oude Elferink
- Tytgat Institute for Liver and Intestinal Research, Research Institute AGEM, Amsterdam UMC, the Netherlands.
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2
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Cheng T, Jiang B, Xu M, Yuan C, Tai M, Wu H, Lu B, Sun P, Jiang X, Zhang X. NDUFS4 promotes tumor progression and predicts prognosis in gastric cancer. Carcinogenesis 2022; 43:980-987. [PMID: 36044738 DOI: 10.1093/carcin/bgac074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 08/10/2022] [Accepted: 08/30/2022] [Indexed: 01/13/2023] Open
Abstract
Gastric cancer ranked third worldwide in terms of mortality. The immediate priority is to search for new prognosticative or therapeutic targets. This research aims to examine the function of the NADH:ubiquinone oxidoreductase subunit S4 (NDUFS4) in the malignant phenotype of gastric carcinoma. We analyzed the correlation between NDUFS4 expression and gastric cancer via bioinformatics analysis and cancer tissue microarray via immunohistochemistry. Also, we detected the phenotype change in gastric cancer cells after NDUFS4 was downregulated. NDUFS4's high expression in gastric cancer tissues showed an association with terminal TNM stage and unfavorable survival. Furthermore, downregulation of NDUFS4 decreased gastric cancer cell proliferation, migration and invasion. Nude mouse models revealed that NDUFS4 promotes tumor growth. This investigation highlights the prognostic role of NDUFS4 in gastric cancer. Our results also creatively ascertained NDUFS4 as a candidate for gastric cancer therapeutic targets.
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Affiliation(s)
- Tong Cheng
- Department of Clinical Biobank, Affiliated Hospital of Nantong University & Medical school of Nantong University, Jiangsu 226001, China
| | - Boxuan Jiang
- Department of Clinical Biobank, Affiliated Hospital of Nantong University & Medical school of Nantong University, Jiangsu 226001, China
| | - Manyu Xu
- Department of Clinical Biobank, Affiliated Hospital of Nantong University & Medical school of Nantong University, Jiangsu 226001, China
| | - Chengzhe Yuan
- Department of Clinical Biobank, Affiliated Hospital of Nantong University & Medical school of Nantong University, Jiangsu 226001, China
| | - Mingliang Tai
- Department of Clinical Biobank, Affiliated Hospital of Nantong University & Medical school of Nantong University, Jiangsu 226001, China
| | - Han Wu
- Department of Clinical Biobank, Affiliated Hospital of Nantong University & Medical school of Nantong University, Jiangsu 226001, China
| | - Bing Lu
- Department of Clinical Biobank, Affiliated Hospital of Nantong University & Medical school of Nantong University, Jiangsu 226001, China
| | - Pingping Sun
- Department of Clinical Biobank, Affiliated Hospital of Nantong University & Medical school of Nantong University, Jiangsu 226001, China
| | - Xiaohui Jiang
- Department of General Surgery, Nantong Tumor Hospital, Nantong, Jiangsu 226361, China
| | - Xiaojing Zhang
- Department of Clinical Biobank, Affiliated Hospital of Nantong University & Medical school of Nantong University, Jiangsu 226001, China
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3
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Giannoulis SV, Chenoweth MJ, Saquilayan P, Tyndale RF, Lerman C, Kennedy JL, Zawertailo L, Gonçalves V. Examining the role of mitochondrial genetic variation in nicotine dependence. Psychiatry Res 2022; 310:114452. [PMID: 35227992 DOI: 10.1016/j.psychres.2022.114452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 01/31/2022] [Accepted: 02/15/2022] [Indexed: 10/19/2022]
Abstract
Nicotine dependence (ND) has a heritability rate of ∼50%, suggesting genetic factors contribute to underlying mechanisms. Here, we aimed to examine variants within both mtDNA and the nuclear genome to determine if mitochondrial genes are associated with ND. A total of 129 mtDNA SNPs and 1136 nuclear-encoded mitochondrial genes in a sample of N = 374 Caucasians were selected for analysis. Age of onset of first, occasional, and daily smoking and Fagerström Test for Nicotine Dependence were used as outcomes for the analysis. Linear regression was used to test common variants. Gene analyses were performed using MAGMA. One nuclear mitochondrial SNP, rs78417112 found in the HSD17B4 gene, was significantly associated with the age of onset of occasional smoking. Additionally, one nuclear mitochondrial gene, PRKACA, was significantly associated with age of onset of both first and occasional smoking. Replication testing of the mtDNA m.1700T>C SNP, nominally associated with age of onset of daily smoking, was available in the PNAT2 clinical trial (N = 930 Caucasians). A meta-analysis showed this SNP was associated with age of onset of daily smoking (p-value = 0.004). Overall, the findings suggest mitochondrial genetic variation may contribute to variability in smoking phenotypes, although replication in larger samples is required.
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Affiliation(s)
- Stavroula V Giannoulis
- Molecular Brain Sciences Department, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, CAMH, 250 College Street, M5T 1R8, Toronto, ON, Canada; Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Meghan J Chenoweth
- Molecular Brain Sciences Department, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, CAMH, 250 College Street, M5T 1R8, Toronto, ON, Canada; Department of Pharmacology and Toxicology, University of Toronto, ON, Canada
| | - Paulo Saquilayan
- Molecular Brain Sciences Department, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, CAMH, 250 College Street, M5T 1R8, Toronto, ON, Canada; Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, ON, Canada; Nicotine Dependence Clinic, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Rachel F Tyndale
- Molecular Brain Sciences Department, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, CAMH, 250 College Street, M5T 1R8, Toronto, ON, Canada; Department of Pharmacology and Toxicology, University of Toronto, ON, Canada; Division of Addictions, Centre for Addiction and Mental Health, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Caryn Lerman
- Department of Psychiatry and USC Norris Comprehensive Cancer Center, University of Southern California, 1441 Eastlake Avenue, Cancer Center, Los Angeles, CA 90089, United States
| | - James L Kennedy
- Molecular Brain Sciences Department, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, CAMH, 250 College Street, M5T 1R8, Toronto, ON, Canada; Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Laurie Zawertailo
- Molecular Brain Sciences Department, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, CAMH, 250 College Street, M5T 1R8, Toronto, ON, Canada; Department of Pharmacology and Toxicology, University of Toronto, ON, Canada; Nicotine Dependence Clinic, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Vanessa Gonçalves
- Molecular Brain Sciences Department, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, CAMH, 250 College Street, M5T 1R8, Toronto, ON, Canada; Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, ON, Canada; Department of Pharmacology and Toxicology, University of Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada.
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4
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Padavannil A, Ayala-Hernandez MG, Castellanos-Silva EA, Letts JA. The Mysterious Multitude: Structural Perspective on the Accessory Subunits of Respiratory Complex I. Front Mol Biosci 2022; 8:798353. [PMID: 35047558 PMCID: PMC8762328 DOI: 10.3389/fmolb.2021.798353] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 11/25/2021] [Indexed: 01/10/2023] Open
Abstract
Complex I (CI) is the largest protein complex in the mitochondrial oxidative phosphorylation electron transport chain of the inner mitochondrial membrane and plays a key role in the transport of electrons from reduced substrates to molecular oxygen. CI is composed of 14 core subunits that are conserved across species and an increasing number of accessory subunits from bacteria to mammals. The fact that adding accessory subunits incurs costs of protein production and import suggests that these subunits play important physiological roles. Accordingly, knockout studies have demonstrated that accessory subunits are essential for CI assembly and function. Furthermore, clinical studies have shown that amino acid substitutions in accessory subunits lead to several debilitating and fatal CI deficiencies. Nevertheless, the specific roles of CI’s accessory subunits have remained mysterious. In this review, we explore the possible roles of each of mammalian CI’s 31 accessory subunits by integrating recent high-resolution CI structures with knockout, assembly, and clinical studies. Thus, we develop a framework of experimentally testable hypotheses for the function of the accessory subunits. We believe that this framework will provide inroads towards the complete understanding of mitochondrial CI physiology and help to develop strategies for the treatment of CI deficiencies.
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Affiliation(s)
- Abhilash Padavannil
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, United States
| | - Maria G Ayala-Hernandez
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, United States
| | - Eimy A Castellanos-Silva
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, United States
| | - James A Letts
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, United States
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5
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Allosteric Regulation of NCLX by Mitochondrial Membrane Potential Links the Metabolic State and Ca 2+ Signaling in Mitochondria. Cell Rep 2019; 25:3465-3475.e4. [PMID: 30566870 DOI: 10.1016/j.celrep.2018.11.084] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 10/24/2018] [Accepted: 11/21/2018] [Indexed: 12/19/2022] Open
Abstract
Calcium is a key regulator of mitochondrial function under both normal and pathological conditions. The mechanisms linking metabolic activity to mitochondrial Ca2+ signaling remain elusive, however. Here, by monitoring mitochondrial Ca2+ transients while manipulating mitochondrial membrane potential (ΔΨm), we found that mild fluctuations in ΔΨm, which do not affect Ca2+ influx, are sufficient to strongly regulate NCLX, the major efflux pathway of Ca2+ from the mitochondria. Phosphorylation of NCLX or expression of phosphomimicking mutant (S258D) rescued NCLX activity from ΔΨm-driven allosteric inhibition. By screening ΔΨm sensitivity of NCLX mutants, we also identified amino acid residues that, through functional interaction with Ser258, control NCLX regulation. Finally, we find that glucose-driven ΔΨm changes in pancreatic β-cells control mitochondrial Ca2+ signaling primarily via NCLX regulation. Our results identify a feedback control between metabolic activity and mitochondrial Ca2+ signaling and the "safety valve" NCLX phosphorylation that can rescue Ca2+ efflux in depolarized mitochondria.
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Ono T, Kamimura N, Matsuhashi T, Nagai T, Nishiyama T, Endo J, Hishiki T, Nakanishi T, Shimizu N, Tanaka H, Ohta S, Suematsu M, Ieda M, Sano M, Fukuda K, Kaneda R. The histone 3 lysine 9 methyltransferase inhibitor chaetocin improves prognosis in a rat model of high salt diet-induced heart failure. Sci Rep 2017; 7:39752. [PMID: 28051130 PMCID: PMC5209701 DOI: 10.1038/srep39752] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 11/18/2016] [Indexed: 12/20/2022] Open
Abstract
Histone acetylation has been linked to cardiac hypertrophy and heart failure. However, the pathological implications of changes in histone methylation and the effects of interventions with histone methyltransferase inhibitors for heart failure have not been fully clarified. Here, we focused on H3K9me3 status in the heart and investigated the effects of the histone H3K9 methyltransferase inhibitor chaetocin on prognoses in Dahl salt-sensitive rats, an animal model of chronic heart failure. Chaetocin prolonged survival and restored mitochondrial dysfunction. ChIP-seq analysis demonstrated that chronic stress to the heart induced H3K9me3 elevation in thousands of repetitive elements, including intronic regions of mitochondria-related genes, such as the gene encoding peroxisome proliferator-activated receptor-gamma coactivator 1 alpha. Furthermore, chaetocin reversed this effect on these repetitive loci. These data suggested that excessive heterochromatinization of repetitive elements of mitochondrial genes in the failing heart may lead to the silencing of genes and impair heart function. Thus, chaetocin may be a potential therapeutic agent for chronic heart failure.
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Affiliation(s)
- Tomohiko Ono
- Department of Cardiology, Keio University School of Medicine, Shinjuku-ku Tokyo, Japan
| | - Naomi Kamimura
- Department of Biochemistry and Cell Biology, Institute of Development and Aging Sciences, Graduate School of Medicine, Nippon Medical School, Kawasaki, Kanagawa, Japan
| | - Tomohiro Matsuhashi
- Department of Cardiology, Keio University School of Medicine, Shinjuku-ku Tokyo, Japan
| | - Toshihiro Nagai
- Electron Microscope Laboratory, Keio University Hospital, Shinjuku-ku, Tokyo, Japan
| | - Takahiko Nishiyama
- Department of Cardiology, Keio University School of Medicine, Shinjuku-ku Tokyo, Japan
| | - Jin Endo
- Department of Cardiology, Keio University School of Medicine, Shinjuku-ku Tokyo, Japan
| | - Takako Hishiki
- Department of Biochemistry, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
- Clinical and Translational Research Center, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
| | - Tsuyoshi Nakanishi
- Department of Biochemistry, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
- MS Business Unit, Shimadzu Corporation, Kyoto, Japan
| | - Noriaki Shimizu
- Division of Rheumatology, Center for Antibody and Vaccine Therapy, IMSUT Hospital, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, Japan
| | - Hirotoshi Tanaka
- Division of Rheumatology, Center for Antibody and Vaccine Therapy, IMSUT Hospital, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, Japan
| | - Shigeo Ohta
- Department of Biochemistry and Cell Biology, Institute of Development and Aging Sciences, Graduate School of Medicine, Nippon Medical School, Kawasaki, Kanagawa, Japan
| | - Makoto Suematsu
- Department of Biochemistry, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
| | - Masaki Ieda
- Department of Cardiology, Keio University School of Medicine, Shinjuku-ku Tokyo, Japan
| | - Motoaki Sano
- Department of Cardiology, Keio University School of Medicine, Shinjuku-ku Tokyo, Japan
| | - Keiichi Fukuda
- Department of Cardiology, Keio University School of Medicine, Shinjuku-ku Tokyo, Japan
| | - Ruri Kaneda
- Department of Cardiology, Keio University School of Medicine, Shinjuku-ku Tokyo, Japan
- Division of Anti-aging Medicine, Center for Molecular Medicine, Jichi Medical University, Shimotsukeshi, Tochigi, Japan
- JST, PRESTO, Kawaguchi, Saitama, Japan
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7
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Skladnev NV, Ganeshan V, Kim JY, Burton TJ, Mitrofanis J, Stone J, Johnstone DM. Widespread brain transcriptome alterations underlie the neuroprotective actions of dietary saffron. J Neurochem 2016; 139:858-871. [PMID: 27696408 DOI: 10.1111/jnc.13857] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 09/21/2016] [Accepted: 09/21/2016] [Indexed: 12/21/2022]
Abstract
Dietary saffron has shown promise as a neuroprotective intervention in clinical trials of retinal degeneration and dementia and in animal models of multiple CNS disorders, including Parkinson's disease. This therapeutic potential makes it important to define the relationship between dose and protection and the mechanisms involved. To explore these two issues, mice were pre-conditioned by providing an aqueous extract of saffron (0.01% w/v) as their drinking water for 2, 5 or 10 days before administration of the parkinsonian neurotoxin MPTP (50 mg/kg). Five days of saffron pre-conditioning provided the greatest benefit against MPTP-induced neuropathology, significantly mitigating both loss of functional dopaminergic cells in the substantia nigra pars compacta (p < 0.01) and abnormal neuronal activity in the caudate-putamen complex (p < 0.0001). RNA microarray analysis of the brain transcriptome of mice pre-conditioned with saffron for 5 days revealed differential expression of 424 genes. Bioinformatics analysis identified enrichment of molecular pathways (e.g. adherens junction, TNFR1 and Fas signaling) and expression changes in candidate genes (Cyr61, Gpx8, Ndufs4, and Nos1ap) with known neuroprotective actions. The apparent biphasic nature of the dose-response relationship between saffron and measures of neuroprotection, together with the stress-inducible nature of many of the up-regulated genes and pathways, lend credence to the idea that saffron, like various other phytochemicals, is a hormetic stimulus, with functions beyond its strong antioxidant capacity. These findings provide impetus for a more comprehensive evaluation of saffron as a neuroprotective intervention.
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Affiliation(s)
- Nicholas V Skladnev
- Bosch Institute, University of Sydney, Sydney, NSW, Australia.,Discipline of Physiology, University of Sydney, Sydney, NSW, Australia
| | - Varshika Ganeshan
- Bosch Institute, University of Sydney, Sydney, NSW, Australia.,Discipline of Physiology, University of Sydney, Sydney, NSW, Australia
| | - Ji Yeon Kim
- Bosch Institute, University of Sydney, Sydney, NSW, Australia.,Discipline of Physiology, University of Sydney, Sydney, NSW, Australia.,School of Medicine, University of Queensland Centre for Clinical Research, Brisbane, Qld, Australia
| | - Thomas J Burton
- Bosch Institute, University of Sydney, Sydney, NSW, Australia.,Discipline of Physiology, University of Sydney, Sydney, NSW, Australia
| | - John Mitrofanis
- Bosch Institute, University of Sydney, Sydney, NSW, Australia.,Discipline of Anatomy & Histology, University of Sydney, Sydney, NSW, Australia
| | - Jonathan Stone
- Bosch Institute, University of Sydney, Sydney, NSW, Australia.,Discipline of Physiology, University of Sydney, Sydney, NSW, Australia
| | - Daniel M Johnstone
- Bosch Institute, University of Sydney, Sydney, NSW, Australia.,Discipline of Physiology, University of Sydney, Sydney, NSW, Australia
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8
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Chintalapudi SR, Morales-Tirado VM, Williams RW, Jablonski MM. Multipronged approach to identify and validate a novel upstream regulator of Sncg in mouse retinal ganglion cells. FEBS J 2016; 283:678-93. [PMID: 26663874 DOI: 10.1111/febs.13620] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 10/22/2015] [Accepted: 12/03/2015] [Indexed: 11/26/2022]
Abstract
Loss of retinal ganglion cells (RGCs) is one of the hallmarks of retinal neurodegenerative diseases, glaucoma being one of the most common. Mechanistic studies on RGCs are hindered by the lack of sufficient primary cells and consensus regarding their signature markers. Recently, γ-synuclein (SNCG) has been shown to be highly expressed in the somas and axons of RGCs. In various mouse models of glaucoma, downregulation of Sncg gene expression correlates with RGC loss. To investigate the role of Sncg in RGCs, we used a novel systems genetics approach to identify a gene that modulates Sncg expression, followed by confirmatory studies in both healthy and diseased retinae. We found that chromosome 1 harbors an expression quantitative trait locus that modulates Sncg expression in the mouse retina, and identified the prefoldin-2 (PFDN2) gene as the candidate upstream modulator of Sncg expression. Our immunohistochemical analyses revealed similar expression patterns in both mouse and human healthy retinae, with PFDN2 colocalizing with SNCG in RGCs and their axons. In contrast, in retinae from glaucoma subjects, SNCG levels were significantly reduced, although PFDN2 levels were maintained. Using a novel flow cytometry-based RGC isolation method, we obtained viable populations of murine RGCs. Knocking down Pfdn2 expression in primary murine RGCs significantly reduced Sncg expression, confirming that Pfdn2 regulates Sncg expression in murine RGCs. Gene Ontology analysis indicated shared mitochondrial function associated with Sncg and Pfdn2. These data solidify the relationship between Sncg and Pfdn2 in RGCs, and provide a novel mechanism for maintaining RGC health.
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Affiliation(s)
- Sumana R Chintalapudi
- Department of Ophthalmology, The Hamilton Eye Institute, The University of Tennessee Health Science Center, Memphis, TN, USA.,Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Vanessa M Morales-Tirado
- Department of Ophthalmology, The Hamilton Eye Institute, The University of Tennessee Health Science Center, Memphis, TN, USA.,Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA.,Department of Microbiology, Immunology and Biochemistry, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Robert W Williams
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA.,Department of Genetics, Genomics and Informatics, The University of Tennessee Health Science Center, Memphis, TN, USA
| | - Monica M Jablonski
- Department of Ophthalmology, The Hamilton Eye Institute, The University of Tennessee Health Science Center, Memphis, TN, USA.,Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA
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9
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Cardiovascular and Hepatic Toxicity of Cocaine: Potential Beneficial Effects of Modulators of Oxidative Stress. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2016:8408479. [PMID: 26823954 PMCID: PMC4707355 DOI: 10.1155/2016/8408479] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 10/19/2015] [Accepted: 11/01/2015] [Indexed: 12/20/2022]
Abstract
Oxidative stress (OS) is thought to play an important role in the pharmacological and toxic effects of various drugs of abuse. Herein we review the literature on the mechanisms responsible for the cardiovascular and hepatic toxicity of cocaine with special focus on OS-related mechanisms. We also review the preclinical and clinical literature concerning the putative therapeutic effects of OS modulators (such as N-acetylcysteine, superoxide dismutase mimetics, nitroxides and nitrones, NADPH oxidase inhibitors, xanthine oxidase inhibitors, and mitochondriotropic antioxidants) for the treatment of cocaine toxicity. We conclude that available OS modulators do not appear to have clinical efficacy.
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10
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Lark DS, Reese LR, Ryan TE, Torres MJ, Smith CD, Lin CT, Neufer PD. Protein Kinase A Governs Oxidative Phosphorylation Kinetics and Oxidant Emitting Potential at Complex I. Front Physiol 2015; 6:332. [PMID: 26635618 PMCID: PMC4646981 DOI: 10.3389/fphys.2015.00332] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 11/02/2015] [Indexed: 11/24/2022] Open
Abstract
The mitochondrial electron transport system (ETS) is responsible for setting and maintaining both the energy and redox charges throughout the cell. Reversible phosphorylation of mitochondrial proteins, particularly via the soluble adenylyl cyclase (sAC)/cyclic AMP (cAMP)/Protein kinase A (PKA) axis, has recently been revealed as a potential mechanism regulating the ETS. However, the governance of cAMP/PKA signaling and its implications on ETS function are incompletely understood. In contrast to prior reports using exogenous bicarbonate, we provide evidence that endogenous CO2 produced by increased tricarboxylic acid (TCA) cycle flux is insufficient to increase mitochondrial cAMP levels, and that exogenous addition of membrane permeant 8Br-cAMP does not enhance mitochondrial respiratory capacity. We also report important non-specific effects of commonly used inhibitors of sAC which preclude their use in studies of mitochondrial function. In isolated liver mitochondria, inhibition of PKA reduced complex I-, but not complex II-supported respiratory capacity. In permeabilized myofibers, inhibition of PKA lowered both the Km and Vmax for complex I-supported respiration as well as succinate-supported H2O2 emitting potential. In summary, the data provided here improve our understanding of how mitochondrial cAMP production is regulated, illustrate a need for better tools to examine the impact of sAC activity on mitochondrial biology, and suggest that cAMP/PKA signaling contributes to the governance of electron flow through complex I of the ETS.
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Affiliation(s)
- Daniel S Lark
- East Carolina Diabetes and Obesity Institute Greenville, NC, USA ; Department of Kinesiology, East Carolina University Greenville, NC, USA
| | - Lauren R Reese
- East Carolina Diabetes and Obesity Institute Greenville, NC, USA ; Department of Physiology, Brody School of Medicine, East Carolina University Greenville, NC, USA
| | - Terence E Ryan
- East Carolina Diabetes and Obesity Institute Greenville, NC, USA ; Department of Physiology, Brody School of Medicine, East Carolina University Greenville, NC, USA
| | - Maria J Torres
- East Carolina Diabetes and Obesity Institute Greenville, NC, USA ; Department of Kinesiology, East Carolina University Greenville, NC, USA
| | - Cody D Smith
- East Carolina Diabetes and Obesity Institute Greenville, NC, USA ; Department of Physiology, Brody School of Medicine, East Carolina University Greenville, NC, USA
| | - Chien-Te Lin
- East Carolina Diabetes and Obesity Institute Greenville, NC, USA ; Department of Physiology, Brody School of Medicine, East Carolina University Greenville, NC, USA
| | - P Darrell Neufer
- East Carolina Diabetes and Obesity Institute Greenville, NC, USA ; Department of Kinesiology, East Carolina University Greenville, NC, USA ; Department of Physiology, Brody School of Medicine, East Carolina University Greenville, NC, USA
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11
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Dagda RK, Das Banerjee T. Role of protein kinase A in regulating mitochondrial function and neuronal development: implications to neurodegenerative diseases. Rev Neurosci 2015; 26:359-70. [PMID: 25741943 DOI: 10.1515/revneuro-2014-0085] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Accepted: 01/08/2015] [Indexed: 11/15/2022]
Abstract
In neurons, enhanced protein kinase A (PKA) signaling elevates synaptic plasticity, promotes neuronal development, and increases dopamine synthesis. By contrast, a decline in PKA signaling contributes to the etiology of several brain degenerative diseases, including Alzheimer's disease and Parkinson's disease, suggesting that PKA predominantly plays a neuroprotective role. A-kinase anchoring proteins (AKAPs) are large multidomain scaffold proteins that target PKA and other signaling molecules to distinct subcellular sites to strategically localize PKA signaling at dendrites, dendritic spines, cytosol, and axons. PKA can be recruited to the outer mitochondrial membrane by associating with three different AKAPs to regulate mitochondrial dynamics, structure, mitochondrial respiration, trafficking, dendrite morphology, and neuronal survival. In this review, we survey the myriad of essential neuronal functions modulated by PKA but place a special emphasis on mitochondrially localized PKA. Finally, we offer an updated overview of how loss of PKA signaling contributes to the etiology of several brain degenerative diseases.
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12
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Anmann T, Varikmaa M, Timohhina N, Tepp K, Shevchuk I, Chekulayev V, Saks V, Kaambre T. Formation of highly organized intracellular structure and energy metabolism in cardiac muscle cells during postnatal development of rat heart. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1350-61. [PMID: 24704335 DOI: 10.1016/j.bbabio.2014.03.015] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 03/25/2014] [Accepted: 03/27/2014] [Indexed: 12/16/2022]
Abstract
Adult cardiomyocytes have highly organized intracellular structure and energy metabolism whose formation during postnatal development is still largely unclear. Our previous results together with the data from the literature suggest that cytoskeletal proteins, particularly βII-tubulin, are involved in the formation of complexes between mitochondria and energy consumption sites. The aim of this study was to examine the arrangement of intracellular architecture parallel to the alterations in regulation of mitochondrial respiration in rat cardiomyocytes during postnatal development, from 1 day to 6 months. Respirometric measurements were performed to study the developmental alterations of mitochondrial function. Changes in the mitochondrial arrangement and cytoarchitecture of βII- and αIV-tubulin were examined by confocal microscopy. Our results show that functional maturation of oxidative phosphorylation in mitochondria is completed much earlier than efficient feedback regulation is established between mitochondria and ATPases via creatine kinase system. These changes are accompanied by significant remodeling of regular intermyofibrillar mitochondrial arrays aligned along the bundles of βII-tubulin. Additionally, we demonstrate that formation of regular arrangement of mitochondria is not sufficient per se to provide adult-like efficiency in metabolic feed-back regulation, but organized tubulin networks and reduction in mitochondrial outer membrane permeability for ADP are necessary as well. In conclusion, cardiomyocytes in rat heart become mature on the level of intracellular architecture and energy metabolism at the age of 3 months.
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Affiliation(s)
- Tiia Anmann
- Laboratory of Bioenergetics, National Institute of Chemical Physics and Biophysics, Tallinn, Estonia.
| | - Minna Varikmaa
- Laboratory of Bioenergetics, National Institute of Chemical Physics and Biophysics, Tallinn, Estonia; Faculty of Science, Department of Chemistry, Tallinn University of Technology, Tallinn, Estonia
| | - Natalja Timohhina
- Laboratory of Bioenergetics, National Institute of Chemical Physics and Biophysics, Tallinn, Estonia
| | - Kersti Tepp
- Laboratory of Bioenergetics, National Institute of Chemical Physics and Biophysics, Tallinn, Estonia
| | - Igor Shevchuk
- Laboratory of Bioenergetics, National Institute of Chemical Physics and Biophysics, Tallinn, Estonia
| | - Vladimir Chekulayev
- Laboratory of Bioenergetics, National Institute of Chemical Physics and Biophysics, Tallinn, Estonia
| | - Valdur Saks
- Laboratory of Bioenergetics, National Institute of Chemical Physics and Biophysics, Tallinn, Estonia; Laboratory of Fundamental and Applied Bioenergetics, Joseph Fourier University, Grenoble, France
| | - Tuuli Kaambre
- Laboratory of Bioenergetics, National Institute of Chemical Physics and Biophysics, Tallinn, Estonia; Institute of Mathematics and Natural Sciences, Tallinn University, Tallinn, Estonia
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13
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Napoli E, Wong S, Hung C, Ross-Inta C, Bomdica P, Giulivi C. Defective mitochondrial disulfide relay system, altered mitochondrial morphology and function in Huntington's disease. Hum Mol Genet 2013; 22:989-1004. [PMID: 23197653 PMCID: PMC8482967 DOI: 10.1093/hmg/dds503] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 11/07/2012] [Accepted: 11/26/2012] [Indexed: 01/09/2024] Open
Abstract
A number of studies have been conducted that link mitochondrial dysfunction (MD) to Huntington's disease (HD); however, contradicting results had resulted in a lack of a clear mechanism that links expression of mutant Huntingtin protein and MD. Mouse homozygous (HM) and heterozygous (HT) mutant striatal cells with two or one allele encoding for a mutant huntingtin protein with 111 polyGln repeats showed a significant impairment of the mitochondrial disulfide relay system (MDRS). This system (consisting of two proteins, Gfer and Mia40) is involved in the mitochondrial import of Cys-rich proteins. The Gfer-to-Mia40 ratio was significantly altered in HM cells compared with controls, along with the expression of mitochondrial proteins considered substrates of the MDRS. In progenitors and differentiated neuron-like HM cells, impairment of MDRS were accompanied by deficient oxidative phosphorylation, Complex I, IV and V activities, decreased mtDNA copy number and transcripts, accumulation of mtDNA deletions and changes in mitochondrial morphology, consistent with other MDRS-deficient biological models, thus providing a framework for the energy deficits observed in this HD model. The majority (>90%) of the mitochondrial outcomes exhibited a gene-dose dependency with the expression of mutant Htt. Finally, decreases in the mtDNA copy number, along with the accumulation of mtDNA deletions, provide a mechanism for the progressive neurodegeneration observed in HD patients.
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Affiliation(s)
- Eleonora Napoli
- Department of Molecular Biosciences, University of California
Davis, Davis, CA 95616, USA
| | - Sarah Wong
- Department of Molecular Biosciences, University of California
Davis, Davis, CA 95616, USA
| | - Connie Hung
- Department of Molecular Biosciences, University of California
Davis, Davis, CA 95616, USA
| | - Catherine Ross-Inta
- Department of Molecular Biosciences, University of California
Davis, Davis, CA 95616, USA
| | - Prithvi Bomdica
- Department of Molecular Biosciences, University of California
Davis, Davis, CA 95616, USA
| | - Cecilia Giulivi
- Department of Molecular Biosciences, University of California
Davis, Davis, CA 95616, USA
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14
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Chen Q, Zeng Y, Wang H, Yang L, Yang Y, Zhu H, Shi Y, Chen W, Hu Y. Molecular characterization and expression analysis of NDUFS4 gene in m. longissimus dorsi of Laiwu pig (Sus scrofa). Mol Biol Rep 2012; 40:1599-608. [PMID: 23073781 DOI: 10.1007/s11033-012-2208-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Accepted: 10/09/2012] [Indexed: 01/13/2023]
Abstract
To study the molecular basis of intramuscular fat (IMF) deposition, suppression subtractive hybridization was used to investigate the differences in gene expression between m. longissimus dorsi (LD) of high IMF Laiwu pig group and low IMF Laiwu pig group. From two specific subtractive cDNA libraries, the expression-upregulated clone HL-27 was selected by reverse Northern high-density blot, and then identified to be pig mitochondrial NADH dehydrogenase (ubiquinone) Fe-S protein 4 (NDUFS4). Pig NDUFS4 full-length cDNA was cloned by RACE, and contains a 528 bp-open reading frame (ORF) encoding 175 amino acid residues. The derived amino acid sequence of NDUFS4 is well conserved compared with NDUFS4 of various species with higher degree of sequence similarity with other mammalian (86.3-92.6 %) than amphibian, aves, and fishes (70.2-81.1 %), and contains one N-linked glycosylation site, one O-linked glycosylation site, seven Ser phosphorylation sites and five Thr phosphorylation sites. A-G mutation was found at nt 122 site of ORF between Laiwu pig and Large White, which results in the K-R mutation at 41 site of protein sequence. Real-time PCR analysis indicated that the level of NDUFS4 mRNA expression was higher in high IMF Laiwu pig group than in low IMF Laiwu pig group, and in Laiwu pig than in Large White. The tissue expression of the pig NDUFS4 gene showed a tissue-specific pattern: highly expressed in LD muscle, spleen and kidney, but hardly expressed in lung, stomach and large intestine. The possible role of NDUFS4 and its relation to IMF deposition are discussed.
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Affiliation(s)
- Qimei Chen
- College of Animal Science and Technology, Shandong Agricultural University, 61 Daizong Street, Tai'an, 271018, People's Republic of China
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15
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Papa S, Martino PL, Capitanio G, Gaballo A, De Rasmo D, Signorile A, Petruzzella V. The oxidative phosphorylation system in mammalian mitochondria. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 942:3-37. [PMID: 22399416 DOI: 10.1007/978-94-007-2869-1_1] [Citation(s) in RCA: 169] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The chapter provides a review of the state of art of the oxidative phosphorylation system in mammalian mitochondria. The sections of the paper deal with: (i) the respiratory chain as a whole: redox centers of the chain and protonic coupling in oxidative phosphorylation (ii) atomic structure and functional mechanism of protonmotive complexes I, III, IV and V of the oxidative phosphorylation system (iii) biogenesis of oxidative phosphorylation complexes: mitochondrial import of nuclear encoded subunits, assembly of oxidative phosphorylation complexes, transcriptional factors controlling biogenesis of the complexes. This advanced knowledge of the structure, functional mechanism and biogenesis of the oxidative phosphorylation system provides a background to understand the pathological impact of genetic and acquired dysfunctions of mitochondrial oxidative phosphorylation.
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Affiliation(s)
- Sergio Papa
- Department of Basic Medical Sciences, University of Bari, Bari, Italy.
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16
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Barhoumi R, Qian Y, Burghardt RC, Tiffany-Castiglioni E. Image analysis of Ca2+ signals as a basis for neurotoxicity assays: promises and challenges. Neurotoxicol Teratol 2009; 32:16-24. [PMID: 19555758 DOI: 10.1016/j.ntt.2009.06.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Revised: 03/12/2009] [Accepted: 06/08/2009] [Indexed: 12/13/2022]
Abstract
Free intracellular calcium ([Ca(2+)](i)) controls a wide range of cellular functions such as contraction, neurotransmitter and hormone release, metabolism, cell division and differentiation. Cytosolic Ca(2+) levels are abnormal in cells exposed to toxicants and understanding how these levels become altered may improve our ability to design high-throughput methods for the sensitive detection of cellular responses to a toxic exposure. Because Ca(2+) is involved in multiple aspects of cellular function, its role in signaling is complex. It is therefore necessary to identify the individual pathways targeted during toxicant exposure in order to use them as a tool for predictive measurements of toxicity and as targets for prevention or reversal of injury. This review illustrates several methods available for analysis of Ca(2+) responses in vitro and their applicability for understanding mechanisms of toxicity at the molecular and cellular levels. The review will also consider the usefulness of Ca(2+) imaging for predicting a unique signature for classes of toxicants. Towards this end, two methodological approaches for assessment of Ca(2+) responses to toxicants are examined: steady state measurements and complex spatial and/or temporal measurements. Each of the methods described and appropriately used results in reliable and reproducible measurements which may be applied in a high-throughput fashion to individualize in vitro assessment of cellular responses caused by toxicants.
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Affiliation(s)
- Rola Barhoumi
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX 77843-4458, USA.
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17
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Eukaryotic complex I: functional diversity and experimental systems to unravel the assembly process. Mol Genet Genomics 2008; 280:93-110. [DOI: 10.1007/s00438-008-0350-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2008] [Accepted: 05/01/2008] [Indexed: 10/21/2022]
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18
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Vogel RO, Smeitink JAM, Nijtmans LGJ. Human mitochondrial complex I assembly: A dynamic and versatile process. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2007; 1767:1215-27. [PMID: 17854760 DOI: 10.1016/j.bbabio.2007.07.008] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2007] [Revised: 07/24/2007] [Accepted: 07/26/2007] [Indexed: 12/12/2022]
Abstract
One can but admire the intricate way in which biomolecular structures are formed and cooperate to allow proper cellular function. A prominent example of such intricacy is the assembly of the five inner membrane embedded enzymatic complexes of the mitochondrial oxidative phosphorylation (OXPHOS) system, which involves the stepwise combination of >80 subunits and prosthetic groups encoded by both the mitochondrial and nuclear genomes. This review will focus on the assembly of the most complicated OXPHOS structure: complex I (NADH:ubiquinone oxidoreductase, EC 1.6.5.3). Recent studies into complex I assembly in human cells have resulted in several models elucidating a thus far enigmatic process. In this review, special attention will be given to the overlap between the various assembly models proposed in different organisms. Complex I being a complicated structure, its assembly must be prone to some form of coordination. This is where chaperone proteins come into play, some of which may relate complex I assembly to processes such as apoptosis and even immunity.
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Affiliation(s)
- Rutger O Vogel
- Nijmegen Centre for Mitochondrial Disorders, Department of Pediatrics, Radboud University Nijmegen Medical Centre, Geert Grooteplein 10, 6500 HB Nijmegen, The Netherlands
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19
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Nagasaka S, Katoh H, Niu CF, Matsui S, Urushida T, Satoh H, Watanabe Y, Hayashi H. Protein kinase A catalytic subunit alters cardiac mitochondrial redox state and membrane potential via the formation of reactive oxygen species. Circ J 2007; 71:429-36. [PMID: 17322647 DOI: 10.1253/circj.71.429] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND The identification of protein kinase A (PKA) anchoring proteins on mitochondria implies a direct effect of PKA on mitochondrial function. However, little is known about the relationship between PKA and mitochondrial metabolism. METHODS AND RESULTS The effects of PKA on the mitochondrial redox state (flavin adenine dinucleotide (FAD)), mitochondrial membrane potential (DeltaPsi(m)) and reactive oxygen species (ROS) production were investigated in saponin-permeabilized rat cardiomyocytes. The PKA catalytic subunit (PKAcat; 50 unit/ml) increased FAD intensities by 56.6+/-7.9% (p<0.01), 2'7'-dichlorofluorescin diacetate (DCF) intensities by 10.5+/-3.3 fold (p<0.01) and depolarized DeltaPsi(m) to 48.1+/-9.5% of the control (p<0.01). Trolox (a ROS scavenger; 100 micromol/L) inhibited PKAcat-induced DeltaPsi(m), FAD and DCF alteration. PKAcat-induced DeltaPsi(m) depolarization was inhibited by an inhibitor of the inner membrane anion channel (IMAC), 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS: 1 micromol/L) but not by an inhibitor of mitochondrial permeability transition pore (mPTP), cyclosporine A (100 nmol/L). CONCLUSIONS PKAcat alters FAD and DeltaPsi(m) via mitochodrial ROS generation, and PKAcat-induced DeltaPsi(m) depolarization was not caused by mPTP but rather by DIDS-sensitive mechanisms, which could be caused by opening of the IMAC. The effects of PKA on mitochondrial function could be related to myocardial function under the condition of extensive beta-adrenergic stimulation.
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Affiliation(s)
- Shiro Nagasaka
- Division of Cardiology, Internal Medicine III, Hamamatsu University School of Medicine, Hamamatsu, Japan
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20
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Jüllig M, Chen X, Hickey AJ, Crossman DJ, Xu A, Wang Y, Greenwood DR, Choong YS, Schönberger SJ, Middleditch MJ, Phillips ARJ, Cooper GJS. Reversal of diabetes-evoked changes in mitochondrial protein expression of cardiac left ventricle by treatment with a copper(II)-selective chelator. Proteomics Clin Appl 2007; 1:387-99. [PMID: 21136691 DOI: 10.1002/prca.200600770] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Indexed: 01/02/2023]
Affiliation(s)
- Mia Jüllig
- Faculty of Science, School of Biological Sciences and Maurice Wilkins Centre of Research Excellence in Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
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21
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Joshi M, Jeoung NH, Popov KM, Harris RA. Identification of a novel PP2C-type mitochondrial phosphatase. Biochem Biophys Res Commun 2007; 356:38-44. [PMID: 17336929 PMCID: PMC1876681 DOI: 10.1016/j.bbrc.2007.02.108] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2007] [Accepted: 02/14/2007] [Indexed: 12/18/2022]
Abstract
A novel phosphatase has been cloned and partially characterized. It has a mitochondrial leader sequence and its amino acid sequence places it in the PP2C family like two known mitochondrial phosphatases. Western blot analysis of subcellular fractions and confocal microscopy of 3T3L1 preadipocytes expressing the GFP-tagged protein confirm its mitochondrial localization. Western blot analysis indicates that the protein is expressed in several mouse tissues, with highest expression in brain, heart, liver, and kidney. The recombinant protein exhibits Mn(2+)-dependent phosphoserine phosphatase activity against the branched-chain alpha-keto acid dehydrogenase complex, suggesting the enzyme may play a role in regulation of branched chain amino acid catabolism. Whether there are other mitochondrial substrates for the enzyme is not known.
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Affiliation(s)
- Mandar Joshi
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202-5122, USA
| | - Nam Ho Jeoung
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202-5122, USA
| | - Kirill M. Popov
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294-1150, USA
| | - Robert A. Harris
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202-5122, USA
- * Corresponding author: Robert A. Harris, Ph.D., Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 1345 W 16 Street, Indianapolis, IN 46202-5122 USA, TEL: +1 317 274 1586.,FAX: +1 317 278 9739., E-mail address:
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22
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Pocsfalvi G, Cuccurullo M, Schlosser G, Scacco S, Papa S, Malorni A. Phosphorylation of B14.5a subunit from bovine heart complex I identified by titanium dioxide selective enrichment and shotgun proteomics. Mol Cell Proteomics 2006; 6:231-7. [PMID: 17114648 DOI: 10.1074/mcp.m600268-mcp200] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Shotgun proteomics was used to study the steady phosphorylation state of NADH:ubiquinone oxidoreductase (complex I) subunits from bovine heart mitochondria. A total tryptic digestion of enzymatically active complex I was performed, and the resulting peptide mixture was subjected to phosphopeptide enrichment by the use of titanium dioxide (TiO2). The phosphopeptide-enriched fraction was separated and analyzed with nanoscale reverse-phase HPLC-ESI-MS/MS in single information-dependent acquisition. Hence two phosphorylated complex I subunits were detected: 42 kDa and B14.5a. Phosphorylation of 42-kDa subunit at Ser-59 has already been determined with fluorescent phosphoprotein-specific gel staining and mass spectrometry (Schilling, B., Aggeler, R., Schulenberg, B., Murray, J., Row, R. H., Capaldi, R. A., and Gibson, B. W. (2005) Mass spectrometric identification of novel phosphorylation site in subunit NDUFA10 of bovine mitochondrial complex I. FEBS Lett. 579, 2485-2490). In our work, this finding was confirmed using a non-gel-based approach. In addition, we report novel phosphorylation on B14.5a nuclear encoded subunit. We demonstrated evidence of the phosphorylation site at Ser-95 residue by collision-induced dissociation experiments on three different molecular ions of two tryptic phosphopeptides of B14.5a.
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Affiliation(s)
- Gabriella Pocsfalvi
- Proteomic and Biomolecular Mass Spectrometry Centre, Institute of Food Science and Technology, Consiglio Nazionale delle Ricerche, 83100 Avellino, Italy.
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23
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Pasdois P, Beauvoit B, Tariosse L, Vinassa B, Bonoron-Adèle S, Santos PD. MitoK(ATP)-dependent changes in mitochondrial volume and in complex II activity during ischemic and pharmacological preconditioning of Langendorff-perfused rat heart. J Bioenerg Biomembr 2006; 38:101-12. [PMID: 17031549 DOI: 10.1007/s10863-006-9016-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2006] [Accepted: 03/02/2006] [Indexed: 10/24/2022]
Abstract
It has been proposed that activation of the mitochondrial ATP-sensitive potassium channel (mitoK(ATP)) is part of signaling pathways triggering the cardioprotection afforded by ischemic preconditioning of the heart. This work was to analyze the mitochondrial function profile of Langendorff-perfused rat hearts during the different phases of various ischemia-reperfusion protocols. Specifically, skinned fibers of ischemic preconditioned hearts exhibit a decline in the succinate-supported respiration and complex II activity during ischemia, followed by a recovery during reperfusion. Meanwhile, the apparent affinity of respiration for ADP (which reflects the matrix volume expansion) is increased during preconditioning stimulus and, to a larger extent, during prolonged ischemia. This evolution pattern is mimicked by diazoxide and abolished by 5-hydroxydecanoate. It is concluded that opening the mitoK(ATP) channel mediates the preservation of mitochondrial structure-function via a mitochondrial matrix shrinkage and a reversible inactivation of complex II during prolonged ischemic insult.
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Affiliation(s)
- Philippe Pasdois
- Inserm U441, Université Victor Segalen Bordeaux 2, Bordeaux, France
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24
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Burgdorf T, van der Linden E, Bernhard M, Yin QY, Back JW, Hartog AF, Muijsers AO, de Koster CG, Albracht SPJ, Friedrich B. The soluble NAD+-Reducing [NiFe]-hydrogenase from Ralstonia eutropha H16 consists of six subunits and can be specifically activated by NADPH. J Bacteriol 2005; 187:3122-32. [PMID: 15838039 PMCID: PMC1082810 DOI: 10.1128/jb.187.9.3122-3132.2005] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The soluble [NiFe]-hydrogenase (SH) of the facultative lithoautotrophic proteobacterium Ralstonia eutropha H16 has up to now been described as a heterotetrameric enzyme. The purified protein consists of two functionally distinct heterodimeric moieties. The HoxHY dimer represents the hydrogenase module, and the HoxFU dimer constitutes an NADH-dehydrogenase. In the bimodular form, the SH mediates reduction of NAD(+) at the expense of H(2). We have purified a new high-molecular-weight form of the SH which contains an additional subunit. This extra subunit was identified as the product of hoxI, a member of the SH gene cluster (hoxFUYHWI). Edman degradation, in combination with protein sequencing of the SH high-molecular-weight complex, established a subunit stoichiometry of HoxFUYHI(2). Cross-linking experiments indicated that the two HoxI subunits are the closest neighbors. The stability of the hexameric SH depended on the pH and the ionic strength of the buffer. The tetrameric form of the SH can be instantaneously activated with small amounts of NADH but not with NADPH. The hexameric form, however, was also activated by adding small amounts of NADPH. This suggests that HoxI provides a binding domain for NADPH. A specific reaction site for NADPH adds to the list of similarities between the SH and mitochondrial NADH:ubiquinone oxidoreductase (Complex I).
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Affiliation(s)
- Tanja Burgdorf
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Chausseestrasse 117, D-10115 Berlin, Germany
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25
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Petruzzella V, Panelli D, Torraco A, Stella A, Papa S. Mutations in theNDUFS4gene of mitochondrial complex I alter stability of the splice variants. FEBS Lett 2005; 579:3770-6. [PMID: 15975579 DOI: 10.1016/j.febslet.2005.05.035] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2005] [Revised: 05/05/2005] [Accepted: 05/10/2005] [Indexed: 11/22/2022]
Abstract
The effect on the stability of alternative transcripts of different mutations of the NDUFS4 gene in patients with Leigh syndrome with complex I deficiency is presented. Normally, two NDUFS4 splice variants are degraded by nonsense mediated mRNA decay (NMD) while a third form does not trigger NMD degradation. In a patient with a premature termination codon in exon 1, all the three splice variants are up-regulated. The present is the first case of a nonsense mutation leading to the abrogation of NMD, which can represent an additional event to be considered in the evaluation of clinically relevant mutations.
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Affiliation(s)
- Vittoria Petruzzella
- Department of Medical Biochemistry and Medical Biology, University of Bari, Piazza G. Cesare, Bari 70124, Italy
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26
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De Matteis F, Harvey C. Inducing coproporphyria in rat hepatocyte cultures using cyclic AMP and cyclic AMP-releasing agents. Arch Toxicol 2005; 79:381-9. [PMID: 15902420 DOI: 10.1007/s00204-004-0637-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2004] [Accepted: 11/17/2004] [Indexed: 11/25/2022]
Abstract
Cyclic AMP (c-AMP), added on its own to rat hepatocyte cultures, caused a marked accumulation of coproporphyrin III. The results obtained by comparing the effect of c-AMP to that of exogenous 5-aminolevulinate (ALA), and from adding c-AMP and ALA together, indicated that the coproporphyrinogen III metabolism was blocked, even though no inhibition of the relevant enzyme, coproporphyrinogen oxidase, could be demonstrated. Preferential accumulation of coproporphyrin could also be produced in cultures of rat hepatocytes by agents that raise the cellular levels of cyclic AMP, such as glucagon. The effect of supplementing the culture medium with triiodothyronine (T3) on the response of rat hepatocytes to c-AMP was also investigated. T3, which is known to stimulate mitochondrial respiration, uncoupling O2 consumption from ATP synthesis, produced a c-AMP-like effect when given on its own and potentiated the effect of c-AMP, with an apparent increase in the severity of the metabolic block. It is suggested that an oxidative mechanism may be activated in c-AMP and T3-induced coproporphyria, preferentially involving the mitochondrial compartment, leading to oxidation of porphyrinogen intermediates of haem biosynthesis, especially coproporphyrinogen. Coproporphyin, the fully oxidized aromatic derivative produced, cannot be metabolized and will therefore accumulate.
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Affiliation(s)
- Francesco De Matteis
- Medical Research Council Bioanalytical Group, School of Biological and Chemical Sciences, Birkbeck College, University of London, Malet Street, London, WC1E 7HX, UK.
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27
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Gibson BW. The human mitochondrial proteome: oxidative stress, protein modifications and oxidative phosphorylation. Int J Biochem Cell Biol 2005; 37:927-34. [PMID: 15743667 DOI: 10.1016/j.biocel.2004.11.013] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2004] [Revised: 11/08/2004] [Accepted: 11/09/2004] [Indexed: 01/15/2023]
Abstract
Mitochondria are one of the most complex of subcellular organelles and play key roles in many cellular functions including energy production, fatty acid metabolism, pyrimidine biosynthesis, calcium homeostasis, and cell signaling. In recent years, we and other groups have attempted to identify the complete set of proteins that are localized to human mitochondria as a way to better understand its cellular functions and how it communicates with other cell compartment in complex signaling pathways such as oxidative stress and apoptosis. Indeed, there is an increasing interest in understanding the molecular details of oxidative stress and the mitochondrial role in this process, as well as assessing how mitochondrial proteins become damaged or posttranslationally modified as a consequence of a major change in a cell's redox status. In this review, we report on the current status of the human mitochondrial proteome with an emphasis towards understanding how mitochondrial proteins, especially the proteins that make up the respiratory chain or oxidative phosphorylation (OXPHOS) enzymes, are modified in various models of age-related diseases such as cancer and Parkinson's disease (PD).
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Affiliation(s)
- Bradford W Gibson
- Chemistry Department, Buck Institute for Age Research, 8001 Redwood Blvd, Novato, CA 94945, USA.
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Scheffler IE, Yadava N, Potluri P. Molecular genetics of complex I-deficient Chinese hamster cell lines. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2005; 1659:160-71. [PMID: 15576048 DOI: 10.1016/j.bbabio.2004.08.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2004] [Revised: 07/28/2004] [Accepted: 08/09/2004] [Indexed: 11/22/2022]
Abstract
The work from our laboratory on complex I-deficient Chinese hamster cell mutants is reviewed. Several complementation groups with a complete defect have been identified. Three of these are due to X-linked mutations, and the mutated genes for two have been identified. We describe null mutants in the genes for the subunits MWFE (gene: NDUFA1) and ESSS. They represent small integral membrane proteins localized in the Ialpha (Igamma) and Ibeta subcomplexes, respectively [J. Hirst, J. Carroll, I.M. Fearnley, R.J. Shannon, J.E. Walker. The nuclear encoded subunits of complex I from bovine heart mitochondria. Biochim. Biophys. Acta 1604 (7-10-2003) 135-150.]. Both are absolutely essential for assembly and activity of complex I. Epitope-tagged versions of these proteins can be expressed from a poly-cistronic vector to complement the mutants, or to be co-expressed with the endogenous proteins in other hamster cell lines (mutant or wild type), or human cells. Structure-function analyses can be performed with proteins altered by site-directed mutagenesis. A cell line has been constructed in which the MWFE subunit is conditionally expressed, opening a window on the kinetics of assembly of complex I. Its targeting, import into mitochondria, and orientation in the inner membrane have also been investigated. The two proteins have recently been shown to be the targets for a cAMP-dependent kinase [R. Chen, I.M. Fearnley, S.Y. Peak_Chew, J.E. Walker. The phosphorylation of subunits of complex I from bovine heart mitochondria. J. Biol. Chem. xx (2004) xx-xx.]. The epitope-tagged proteins can be cross-linked with other complex I subunits.
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Affiliation(s)
- Immo E Scheffler
- Section of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0322, USA.
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Abdrakhmanova A, Zickermann V, Bostina M, Radermacher M, Schägger H, Kerscher S, Brandt U. Subunit composition of mitochondrial complex I from the yeast Yarrowia lipolytica. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2004; 1658:148-56. [PMID: 15282186 DOI: 10.1016/j.bbabio.2004.04.019] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2004] [Revised: 04/29/2004] [Accepted: 04/29/2004] [Indexed: 12/15/2022]
Abstract
Here we present a first assessment of the subunit inventory of mitochondrial complex I from the obligate aerobic yeast Yarrowia lipolytica. A total of 37 subunits were identified. In addition to the seven central, nuclear coded, and the seven mitochondrially coded subunits, 23 accessory subunits were found based on 2D electrophoretic and mass spectroscopic analysis in combination with sequence information from the Y. lipolytica genome. Nineteen of the 23 accessory subunits are clearly conserved between Y. lipolytica and mammals. The remaining four accessory subunits include NUWM, which has no apparent homologue in any other organism and is predicted to contain a single transmembrane domain bounded by highly charged extramembraneous domains. This structural organization is shared among a group of 7 subunits in the Y. lipolytica and 14 subunits in the mammalian enzyme. Because only five of these subunits display significant evolutionary conservation, their as yet unknown function is proposed to be structure- rather than sequence-specific. The NUWM subunit could be assigned to a hydrophobic subcomplex obtained by fragmentation and sucrose gradient centrifugation. Its position within the membrane arm was determined by electron microscopic single particle analysis of Y. lipolytica complex I decorated with a NUWM-specific monoclonal antibody.
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Affiliation(s)
- Albina Abdrakhmanova
- Fachbereich Medizin, Institut für Biochemie I, ZBC, Universität Frankfurt, Theodor-Stern-Kai 7, Haus 25B, D-60590 Frankfurt am Main, Germany
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Kerscher S, Bénit P, Abdrakhmanova A, Zwicker K, Rais I, Karas M, Rustin P, Brandt U. Processing of the 24 kDa subunit mitochondrial import signal is not required for assembly of functional complex I in Yarrowia lipolytica. ACTA ACUST UNITED AC 2004; 271:3588-95. [PMID: 15317595 DOI: 10.1111/j.0014-2956.2004.04296.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A small deletion in the second intron of human NDUFV2 (IVS2+5_+8delGTAA) has been shown to cause hypertrophic cardiomyopathy and encephalomyopathy [Bénit, P., Beugnot, R., Chretien, D., Giurgea, I., de Lonlay-Debeney, P., Issartel, J.P., Kerscher, S., Rustin, P., Rötig, A. & Munnich, A. (2003) Human Mutat.21, 582-586]. Skipping of exon 2 results in a partial deletion of the mitochondrial targeting sequence of the precursor for the 24 kDa subunit of respiratory chain complex I. Immunoreactivity of the 24 kDa subunit and complex I activity, both present at 30-50% of normal levels in patient mitochondria, raised the question of how the mutant 24 kDa subunit precursor can be imported and assembled into functional complex I. In the present study, we have remodelled the human NDUFV2 mutation by deleting codons 17-32 from the orthologous NUHM gene of the obligate aerobic yeast Yarrowia lipolytica. The resulting mutant enzyme was indistinguishable from parental complex I with regard to activity, inhibitor sensitivity and EPR signature. Size, isoelectric point and presumably also N-terminal acetylation were altered, indicating that the residual targeting sequence was retained on the mature 24 kDa protein. Complete removal of the NUHM presequence resulted in the absence of complex I activity, strongly arguing against the presence of an internal mitochondrial targeting sequence within the 24 kDa protein.
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Affiliation(s)
- Stefan Kerscher
- Universität Frankfurt, Fachbereich Medizin, Institut für Biochemie I, Frankfurt am Main, Germany.
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Papa S, Petruzzella V, Scacco S, Vergari R, Panelli D, Tamborra R, Corsi P, Picciariello M, Lambo R, Bertini E, Santorelli FM. Respiratory complex I in brain development and genetic disease. Neurochem Res 2004; 29:547-60. [PMID: 15038602 DOI: 10.1023/b:nere.0000014825.42365.16] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A study is presented on the expression and activity of complex I, as well as of other complexes of the respiratory chain, in the course of brain development and inherited encephalopathies. Investigations on mouse hippocampal cells show that differentiation of these cells both in vivo and in cell cultures is associated with the expression of a functional complex I, whose activity markedly increases with respect to that of complexes III and IV. Data are presented on genetic defects of complex I in six children with inborn encephalopathy associated with isolated deficiency of the complex. Mutations have been identified in nuclear and mitochondrial genes coding for subunits of the complex. Different mutations were found in the nuclear NDUFS4 gene coding for the 18 kD (IP, AQDQ) subunit of complex I. All the NDUFS4 mutations resulted in impairment of the assembly of a functional complex. The observations presented provide evidence showing a critical role of complex I in differentiation and functional activity of brain cells.
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Affiliation(s)
- Sergio Papa
- Department of Medical Biochemistry and Medical Biology, University of Bari, Piazza G. Cesare 70124 Bari, Italy.
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Marín-García J, Goldenthal MJ. Heart mitochondria signaling pathways: appraisal of an emerging field. J Mol Med (Berl) 2004; 82:565-78. [PMID: 15221079 DOI: 10.1007/s00109-004-0567-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2003] [Accepted: 05/18/2004] [Indexed: 12/22/2022]
Abstract
The contribution that mitochondria make to cardiac function extends well beyond their critical bioenergetic role as a supplier of ATP. The organelle plays an integral part in the regulatory and signaling events that occur in response to physiological stresses, including but not limited to myocardial ischemia and reperfusion, hypoxia, oxidative stress, and hormonal and cytokine stimuli. Research on both intact cardiac muscle tissue and cultured cardiomyocytes has just begun to probe the nature and the extent of mitochondrial involvement in interorganelle communication, hypertropic growth, and cell death. This review covers particular aspects of the newly emerging field of mitochondrial medicine offering a critical guide in the assessment of mitochondrial participation at the molecular and biochemical levels in the multiple and interrelated signaling pathways, gauging the effect that mitochondria have as a receiver, integrator, and transmitter of signals on cardiac phenotype. We also discuss future directions that may impact on the treatment of cardiac diseases.
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Affiliation(s)
- José Marín-García
- Molecular Cardiology and Neuromuscular Institute, 75 Raritan Ave, Highland Park, NJ 08904, USA.
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Abstract
PURPOSE OF REVIEW Disturbances in the mitochondrial oxidative phosphorylation pathway most often lead to devastating disorders with a fatal outcome. Of these, complex I deficiency is the most frequently encountered. Recent characterization of the mitochondrial and nuclear DNA-encoded complex I subunits has allowed mutational analysis and reliable prenatal diagnosis. Nevertheless, complex-I-deficient patients without a mutation in any of the known subunits remain. It is assumed that these patients harbour defects in proteins involved in the assembly of this largest member of the oxidative phosphorylation complexes. This review describes current understanding of complex I assembly, new developments and future perspectives. RECENT FINDINGS The first model of human complex I assembly has been proposed recently. New insights into supercomplex assembly and stability may help to explain combined deficiencies. Recent functional characterization of some of the 32 accessory subunits of the complex may link these subunits to complex I biogenesis and activity regulation. SUMMARY Research on complex I assembly is increasing rapidly. However, comparison between theoretical and experimental models of complex I assembly is still problematic. The growing understanding of complex I assembly at the subunit and supercomplex level will clarify the picture in the future. The elucidation of complex I assembly, by combining patient data with new experimental methods, will facilitate the diagnosis of (and possibly therapy for) many uncharacterized mitochondrial disorders.
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Affiliation(s)
- Rutger Vogel
- Nijmegen Centre for Mitochondrial Disorders at the Department of Paediatrics, University Medical Centre Nijmegen, Nijmegen, The Netherlands
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Nijtmans LG, Ugalde C, van den Heuvel LP, Smeitink JA. Function and dysfunction of the oxidative phosphorylation system. MITOCHONDRIAL FUNCTION AND BIOGENESIS 2004. [DOI: 10.1007/b95715] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Scacco S, Petruzzella V, Budde S, Vergari R, Tamborra R, Panelli D, van den Heuvel LP, Smeitink JA, Papa S. Pathological mutations of the human NDUFS4 gene of the 18-kDa (AQDQ) subunit of complex I affect the expression of the protein and the assembly and function of the complex. J Biol Chem 2003; 278:44161-7. [PMID: 12944388 DOI: 10.1074/jbc.m307615200] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Presented is a study of the impact on the structure and function of human complex I of three different homozygous mutations in the NDUFS4 gene coding for the 18-kDa subunit of respiratory complex I, inherited by autosomal recessive mode in three children affected by a fatal neurological Leigh-like syndrome. The mutations consisted, respectively, of a AAGTC duplication at position 466-470 of the coding sequence, a single base deletion at position 289/290, and a G44A nonsense mutation in the first exon of the gene. All three mutations were found to be associated with a defect of the assembly of a functional complex in the inner mitochondrial membrane. In all the mutations, in addition to destruction of the carboxyl-terminal segment of the 18-kDa subunit, the amino-terminal segment of the protein was also missing. In the mutation that was expected to produce a truncated subunit, the disappearance of the protein was associated with an almost complete disappearance of the NDUFS4 transcript. These observations show the essential role of the NDUFS4 gene in the structure and function of complex I and give insight into the pathogenic mechanism of NDUFS4 gene mutations in a severe defect of complex I.
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Affiliation(s)
- Salvatore Scacco
- Department of Medical Biochemistry and Medical Biology, University of Bari, 70124 Bari, Italy
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Maklashina E, Kotlyar AB, Cecchini G. Active/de-active transition of respiratory complex I in bacteria, fungi, and animals. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2003; 1606:95-103. [PMID: 14507430 DOI: 10.1016/s0005-2728(03)00087-2] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mammalian complex I (NADH:ubiquinone oxidoreductase) exists as a mixture of interconvertible active (A) and de-activated (D) forms. The A-form is capable of NADH:quinone-reductase catalysis, but not the D-form. Complex I from the bacterium Paracoccus denitrificans, by contrast, exists only in the A-form. This bacterial complex contains 32 fewer subunits than the mammalian complex. The question arises therefore if the structural complexity of complex I from higher organisms correlates with its ability to undergo the A/D transition. In the present study, it was found that complex I from the bacterium Escherichia coli and from non-vertebrate organisms (earthworm, lobster, and cricket) did not show the A/D transitions. Vertebrate organisms (carp, frog, chicken), however, underwent similar A/D transitions to those of the well-characterized bovine complex I. Further studies showed that complex I from the lower eukaryotes, Neurospora crassa and Yarrowia lipolytica, exhibited very distinct A/D transitions with much lower activation barriers compared to the bovine enzyme. The A/D transitions of complex I as they relate to structure and regulation of enzymatic activity are discussed.
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Affiliation(s)
- Elena Maklashina
- Molecular Biology Division (151-S), VA Medical Center, San Francisco, CA 94121, USA.
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Lasorsa FM, Pinton P, Palmieri L, Fiermonte G, Rizzuto R, Palmieri F. Recombinant expression of the Ca(2+)-sensitive aspartate/glutamate carrier increases mitochondrial ATP production in agonist-stimulated Chinese hamster ovary cells. J Biol Chem 2003; 278:38686-92. [PMID: 12851387 DOI: 10.1074/jbc.m304988200] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Ca(2+)-sensitive dehydrogenases of the mitochondrial matrix are, so far, the only known effectors to allow Ca2+ signals to couple the activation of plasma membrane receptors to the stimulation of aerobic metabolism. In this study, we demonstrate a novel mechanism, based on Ca(2+)-sensitive metabolite carriers of the inner membrane. We expressed in Chinese hamster ovary cells aralar1 and citrin, aspartate/glutamate exchangers that have Ca(2+)-binding sites in their sequence, and measured mitochondrial Ca2+ and ATP levels as well as cytosolic Ca2+ concentration with targeted recombinant probes. The increase in mitochondrial ATP levels caused by cell stimulation with Ca(2+)-mobilizing agonists was markedly larger in cells expressing aralar and citrin (but not truncated mutants lacking the Ca(2+)-binding site) than in control cells. Conversely, the cytosolic and the mitochondrial Ca2+ signals were the same in control cells and cells expressing the different aralar1 and citrin variants, thus ruling out an indirect effect through the Ca(2+)-sensitive dehydrogenases. Together, these data show that the decoding of Ca2+ signals in mitochondria depends on the coordinate activity of mitochondrial enzymes and carriers, which may thus represent useful pharmacological targets in this process of major pathophysiological interest.
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Affiliation(s)
- Francesco Massimo Lasorsa
- Department of Pharmaco-Biology, Laboratory of Biochemistry and Molecular Biology, University of Bari and CNR Institute of Biomembranes and Bioenergetics, Via Orabona 4, 70125 Bari, Italy
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