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Berdún R, Obis È, Mota-Martorell N, Bassols A, Valent D, Serrano JCE, Martín-Garí M, Rodríguez-Palmero M, Moreno-Muñoz JA, Tibau J, Quintanilla R, Pamplona R, Portero-Otín M, Jové M. High-Fat Diet-Induced Obesity Increases Brain Mitochondrial Complex I and Lipoxidation-Derived Protein Damage. Antioxidants (Basel) 2024; 13:161. [PMID: 38397759 PMCID: PMC10886272 DOI: 10.3390/antiox13020161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 01/12/2024] [Accepted: 01/24/2024] [Indexed: 02/25/2024] Open
Abstract
Obesity is a risk factor for highly prevalent age-related neurodegenerative diseases, the pathogenesis of whichinvolves mitochondrial dysfunction and protein oxidative damage. Lipoxidation, driven by high levels of peroxidizable unsaturated fatty acids and low antioxidant protection of the brain, stands out as a significant risk factor. To gain information on the relationship between obesity and brain molecular damage, in a porcine model of obesity we evaluated (1) the level of mitochondrial respiratory chain complexes, as the main source of free radical generation, by Western blot; (2) the fatty acid profile by gas chromatography; and (3) the oxidative modification of proteins by mass spectrometry. The results demonstrate a selectively higher amount of the lipoxidation-derived biomarker malondialdehyde-lysine (MDAL) (34% increase) in the frontal cortex, and positive correlations between MDAL and LDL levels and body weight. No changes were observed in brain fatty acid profile by the high-fat diet, and the increased lipid peroxidative modification was associated with increased levels of mitochondrial complex I (NDUFS3 and NDUFA9 subunits) and complex II (flavoprotein). Interestingly, introducing n3 fatty acids and a probiotic in the high-fat diet prevented the observed changes, suggesting that dietary components can modulate protein oxidative modification at the cerebral level and opening new possibilities in neurodegenerative diseases' prevention.
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Affiliation(s)
- Rebeca Berdún
- Department of Experimental Medicine, Lleida Biomedical Research Institute (IRBLleida), University of Lleida (UdL), 25198 Lleida, Spain; (R.B.); (È.O.); (N.M.-M.); (J.C.E.S.); (M.M.-G.); (R.P.)
| | - Èlia Obis
- Department of Experimental Medicine, Lleida Biomedical Research Institute (IRBLleida), University of Lleida (UdL), 25198 Lleida, Spain; (R.B.); (È.O.); (N.M.-M.); (J.C.E.S.); (M.M.-G.); (R.P.)
| | - Natàlia Mota-Martorell
- Department of Experimental Medicine, Lleida Biomedical Research Institute (IRBLleida), University of Lleida (UdL), 25198 Lleida, Spain; (R.B.); (È.O.); (N.M.-M.); (J.C.E.S.); (M.M.-G.); (R.P.)
| | - Anna Bassols
- Departament de Bioquímica i Biologia Molecular, Facultat de Veterinària, Universitat Autònoma de Barcelona, 08025 Barcelona, Spain; (A.B.); (D.V.)
| | - Daniel Valent
- Departament de Bioquímica i Biologia Molecular, Facultat de Veterinària, Universitat Autònoma de Barcelona, 08025 Barcelona, Spain; (A.B.); (D.V.)
| | - José C. E. Serrano
- Department of Experimental Medicine, Lleida Biomedical Research Institute (IRBLleida), University of Lleida (UdL), 25198 Lleida, Spain; (R.B.); (È.O.); (N.M.-M.); (J.C.E.S.); (M.M.-G.); (R.P.)
| | - Meritxell Martín-Garí
- Department of Experimental Medicine, Lleida Biomedical Research Institute (IRBLleida), University of Lleida (UdL), 25198 Lleida, Spain; (R.B.); (È.O.); (N.M.-M.); (J.C.E.S.); (M.M.-G.); (R.P.)
| | - María Rodríguez-Palmero
- Laboratorios Ordesa S.L., Barcelona Science Park, 08028 Barcelona, Spain; (M.R.-P.); (J.A.M.-M.)
| | | | - Joan Tibau
- Animal Science—Institut de Recerca i Tecnologia Agroalimentàries, IRTA, Monells, 17121 Girona, Spain;
| | - Raquel Quintanilla
- Animal Breeding and Genetics Program, IRTA, Torre Marimon, 08140 Caldes de Montbui, Spain;
| | - Reinald Pamplona
- Department of Experimental Medicine, Lleida Biomedical Research Institute (IRBLleida), University of Lleida (UdL), 25198 Lleida, Spain; (R.B.); (È.O.); (N.M.-M.); (J.C.E.S.); (M.M.-G.); (R.P.)
| | - Manuel Portero-Otín
- Department of Experimental Medicine, Lleida Biomedical Research Institute (IRBLleida), University of Lleida (UdL), 25198 Lleida, Spain; (R.B.); (È.O.); (N.M.-M.); (J.C.E.S.); (M.M.-G.); (R.P.)
| | - Mariona Jové
- Department of Experimental Medicine, Lleida Biomedical Research Institute (IRBLleida), University of Lleida (UdL), 25198 Lleida, Spain; (R.B.); (È.O.); (N.M.-M.); (J.C.E.S.); (M.M.-G.); (R.P.)
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2
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Adams RA, Liu Z, Hsieh C, Marko M, Lederer WJ, Jafri MS, Mannella C. Structural Analysis of Mitochondria in Cardiomyocytes: Insights into Bioenergetics and Membrane Remodeling. Curr Issues Mol Biol 2023; 45:6097-6115. [PMID: 37504301 PMCID: PMC10378267 DOI: 10.3390/cimb45070385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 07/15/2023] [Accepted: 07/18/2023] [Indexed: 07/29/2023] Open
Abstract
Mitochondria in mammalian cardiomyocytes display considerable structural heterogeneity, the significance of which is not currently understood. We use electron microscopic tomography to analyze a dataset of 68 mitochondrial subvolumes to look for correlations among mitochondrial size and shape, crista morphology and membrane density, and organelle location within rat cardiac myocytes. A tomographic analysis guided the definition of four classes of crista morphology: lamellar, tubular, mixed and transitional, the last associated with remodeling between lamellar and tubular cristae. Correlations include an apparent bias for mitochondria with lamellar cristae to be located in the regions between myofibrils and a two-fold larger crista membrane density in mitochondria with lamellar cristae relative to mitochondria with tubular cristae. The examination of individual cristae inside mitochondria reveals local variations in crista topology, such as extent of branching, alignment of fenestrations and progressive changes in membrane morphology and packing density. The findings suggest both a rationale for the interfibrillar location of lamellar mitochondria and a pathway for crista remodeling from lamellar to tubular morphology.
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Affiliation(s)
- Raquel A. Adams
- Krasnow Institute for Advanced Study and School of Systems Biology, George Mason University, Fairfax, VA 22030, USA;
| | - Zheng Liu
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA (M.M.)
| | - Chongere Hsieh
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA (M.M.)
| | - Michael Marko
- Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA (M.M.)
| | - W. Jonathan Lederer
- Department of Physiology, School of Medicine, University of Maryland, Baltimore, MD 21201, USA;
- Center for Biomedical Engineering and Technology, School of Medicine, University of Maryland, Baltimore, MD 21201, USA
| | - M. Saleet Jafri
- Krasnow Institute for Advanced Study and School of Systems Biology, George Mason University, Fairfax, VA 22030, USA;
- Center for Biomedical Engineering and Technology, School of Medicine, University of Maryland, Baltimore, MD 21201, USA
| | - Carmen Mannella
- Department of Physiology, School of Medicine, University of Maryland, Baltimore, MD 21201, USA;
- Center for Biomedical Engineering and Technology, School of Medicine, University of Maryland, Baltimore, MD 21201, USA
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3
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Arroum T, Borowski MT, Marx N, Schmelter F, Scholz M, Psathaki OE, Hippler M, Enriquez JA, Busch KB. Loss of respiratory complex I subunit NDUFB10 affects complex I assembly and supercomplex formation. Biol Chem 2023; 404:399-415. [PMID: 36952351 DOI: 10.1515/hsz-2022-0309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 03/06/2023] [Indexed: 03/24/2023]
Abstract
The orchestrated activity of the mitochondrial respiratory or electron transport chain (ETC) and ATP synthase convert reduction power (NADH, FADH2) into ATP, the cell's energy currency in a process named oxidative phosphorylation (OXPHOS). Three out of the four ETC complexes are found in supramolecular assemblies: complex I, III, and IV form the respiratory supercomplexes (SC). The plasticity model suggests that SC formation is a form of adaptation to changing conditions such as energy supply, redox state, and stress. Complex I, the NADH-dehydrogenase, is part of the largest supercomplex (CI + CIII2 + CIVn). Here, we demonstrate the role of NDUFB10, a subunit of the membrane arm of complex I, in complex I and supercomplex assembly on the one hand and bioenergetics function on the other. NDUFB10 knockout was correlated with a decrease of SCAF1, a supercomplex assembly factor, and a reduction of respiration and mitochondrial membrane potential. This likely is due to loss of proton pumping since the CI P P -module is downregulated and the P D -module is completely abolished in NDUFB10 knock outs.
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Affiliation(s)
- Tasnim Arroum
- Institute of Integrative Cell Biology and Physiology, Bioenergetics and Mitochondrial Dynamics Section, University of Münster, Schloßplatz 5, D-49078 Münster, Germany
| | - Marie-Theres Borowski
- Institute of Integrative Cell Biology and Physiology, Bioenergetics and Mitochondrial Dynamics Section, University of Münster, Schloßplatz 5, D-49078 Münster, Germany
| | - Nico Marx
- Institute of Integrative Cell Biology and Physiology, Bioenergetics and Mitochondrial Dynamics Section, University of Münster, Schloßplatz 5, D-49078 Münster, Germany
| | - Frank Schmelter
- Institute of Integrative Cell Biology and Physiology, Bioenergetics and Mitochondrial Dynamics Section, University of Münster, Schloßplatz 5, D-49078 Münster, Germany
| | - Martin Scholz
- Institute of Plant Biotechnology, University of Münster, Schloßplatz 5, D-49078 Münster, Germany
| | - Olympia Ekaterini Psathaki
- Center of Cellular Nanoanalytics, Integrated Bioimaging Facility, University of Osnabrück, Barbarastr. 11, D-49076 Osnabrück, Germany
| | - Michael Hippler
- Institute of Plant Biotechnology, University of Münster, Schloßplatz 5, D-49078 Münster, Germany
| | - José Antonio Enriquez
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), Melchor Fernández Almagro 3, E-28029 Madrid, Spain
- Centro de Investigaciones Biomédicas en Red en Fraglidad y Envejecimiento Saludable (CIBERFES), Av. Monforte de Lemos, 3-5, Pabellón 11, Planta 0, E-28029 Madrid, Spain
| | - Karin B Busch
- Institute of Integrative Cell Biology and Physiology, Bioenergetics and Mitochondrial Dynamics Section, University of Münster, Schloßplatz 5, D-49078 Münster, Germany
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Markevich NI, Markevich LN. Mathematical Modeling of ROS Production and Diode-like Behavior in the SDHA/SDHB Subcomplex of Succinate Dehydrogenases in Reverse Quinol-Fumarate Reductase Direction. Int J Mol Sci 2022; 23:ijms232415596. [PMID: 36555239 PMCID: PMC9778801 DOI: 10.3390/ijms232415596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 12/06/2022] [Accepted: 12/07/2022] [Indexed: 12/14/2022] Open
Abstract
Succinate dehydrogenase (SDH) plays an important role in reverse electron transfer during hypoxia/anoxia, in particular, in ischemia, when blood supply to an organ is disrupted, and oxygen is not available. It was detected in the voltammetry studies about three decades ago that the SDHA/SDHB subcomplex of SDH can have such a strong nonlinear property as a "tunnel-diode" behavior in reverse quinol-fumarate reductase direction. The molecular and kinetic mechanisms of this phenomenon, that is, a strong drop in the rate of fumarate reduction as the driving force is increased, are still unclear. In order to account for this property of SDH, we developed and analyzed a mechanistic computational model of reverse electron transfer in the SDHA/SDHB subcomplex of SDH. It was shown that a decrease in the rate of succinate release from the active center during fumarate reduction quantitatively explains the experimentally observed tunnel-diode behavior in SDH and threshold values of the electrode potential of about -80 mV. Computational analysis of ROS production in the SDHA/SDHB subcomplex of SDH during reverse electron transfer predicts that the rate of ROS production decreases when the tunnel-diode behavior appears. These results predict a low rate of ROS production by the SDHA/SDHB subcomplex of SDH during ischemia.
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Affiliation(s)
- Nikolay I. Markevich
- Institute of Theoretical and Experimental Biophysics of RAS, 142290 Pushchino, Russia
- Correspondence:
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5
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Probing the Role of Cysteine Thiyl Radicals in Biology: Eminently Dangerous, Difficult to Scavenge. Antioxidants (Basel) 2022; 11:antiox11050885. [PMID: 35624747 PMCID: PMC9137623 DOI: 10.3390/antiox11050885] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 04/21/2022] [Accepted: 04/23/2022] [Indexed: 11/17/2022] Open
Abstract
Thiyl radicals are exceptionally interesting reactive sulfur species (RSS), but rather rarely considered in a biological or medical context. We here review the reactivity of protein thiyl radicals in aqueous and lipid phases and provide an overview of their most relevant reaction partners in biological systems. We deduce that polyunsaturated fatty acids (PUFAs) are their preferred reaction substrates in lipid phases, whereas protein side chains arguably prevail in aqueous phases. In both cellular compartments, a single, dominating thiyl radical-specific antioxidant does not seem to exist. This conclusion is rationalized by the high reaction rate constants of thiyl radicals with several highly concentrated substrates in the cell, precluding effective interception by antioxidants, especially in lipid bilayers. The intractable reactivity of thiyl radicals may account for a series of long-standing, but still startling biochemical observations surrounding the amino acid cysteine: (i) its global underrepresentation on protein surfaces, (ii) its selective avoidance in aerobic lipid bilayers, especially the inner mitochondrial membrane, (iii) the inverse correlation between cysteine usage and longevity in animals, (iv) the mitochondrial synthesis and translational incorporation of cysteine persulfide, and potentially (v) the ex post introduction of selenocysteine into the genetic code.
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Manoj KM, Gideon DA, Jaeken L. Why do cells need oxygen? Insights from mitochondrial composition and function. Cell Biol Int 2021; 46:344-358. [PMID: 34918410 DOI: 10.1002/cbin.11746] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/07/2021] [Accepted: 12/14/2021] [Indexed: 02/03/2023]
Abstract
Mitochondrial membrane-embedded redox proteins are classically perceived as deterministic "electron transport chain" (ETC) arrays cum proton pumps; and oxygen is seen as an "immobile terminal electron acceptor." This is untenable because: (1) there are little free protons to be pumped out of the matrix; (2) proton pumping would be highly endergonic; (3) ETC-chemiosmosis-rotary ATP synthesis proposal is "irreducibly complex"/"non-evolvable" and does not fit with mitochondrial architecture or structural/distribution data of the concerned proteins/components; (4) a plethora of experimental observations do not conform to the postulates/requisites; for example, there is little evidence for viable proton-pumps/pH-gradient in mitochondria, trans-membrane potential (TMP) is non-fluctuating/non-trappable, oxygen is seen to give copious "diffusible reactive (oxygen) species" (DRS/DROS) in milieu, etc. Quite contrarily, the newly proposed murburn model's tenets agree with known principles of energetics/kinetics, and builds on established structural data and reported observations. In this purview, oxygen is needed to make DRS, the principal component of mitochondrial function. Complex V and porins respectively serve as proton-inlet and turgor-based water-exodus portals, thereby achieving organellar homeostasis. Complexes I to IV possess ADP-binding sites and their redox-centers react/interact with O2 /DRS. At/around these complexes, DRS cross-react or activate/oxidize ADP/Pi via fast thermogenic one-electron reaction(s), condensing to form two-electron stabilized products (H2 O2 /H2 O/ATP). The varied architecture and distribution of components in mitochondria validate DRS as (i) the coupling agent of oxidative reactions and phosphorylations, and (ii) the primary reason for manifestation of TMP in steady-state. Explorations along the new precepts stand to provide greater insights on mitochondrial function and pathophysiology.
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Affiliation(s)
- Kelath Murali Manoj
- Department of Biochemistry, Satyamjayatu: The Science & Ethics Foundation, Kerala, India
| | - Daniel Andrew Gideon
- Department of Biochemistry, Satyamjayatu: The Science & Ethics Foundation, Kerala, India
| | - Laurent Jaeken
- Industrial Sciences and Technology, Karel de Grote-Hogeschool, Association University and High Schools Antwerp, Antwerpen, Belgium
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Mookerjee SA, Gerencser AA, Watson MA, Brand MD. Controlled power: how biology manages succinate-driven energy release. Biochem Soc Trans 2021; 49:2929-2939. [PMID: 34882231 PMCID: PMC8786295 DOI: 10.1042/bst20211032] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 11/08/2021] [Accepted: 11/22/2021] [Indexed: 12/13/2022]
Abstract
Oxidation of succinate by mitochondria can generate a higher protonmotive force (pmf) than can oxidation of NADH-linked substrates. Fundamentally, this is because of differences in redox potentials and gearing. Biology adds kinetic constraints that tune the oxidation of NADH and succinate to ensure that the resulting mitochondrial pmf is suitable for meeting cellular needs without triggering pathology. Tuning within an optimal range is used, for example, to shift ATP consumption between different consumers. Conditions that overcome these constraints and allow succinate oxidation to drive pmf too high can cause pathological generation of reactive oxygen species. We discuss the thermodynamic properties that allow succinate oxidation to drive pmf higher than NADH oxidation, and discuss the evidence for kinetic tuning of ATP production and for pathologies resulting from substantial succinate oxidation in vivo.
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Affiliation(s)
- Shona A. Mookerjee
- Department of Biological and Pharmaceutical Sciences, Touro University California College of Pharmacy, Vallejo, CA, U.S.A
- Buck Institute for Research on Aging, Novato, CA, U.S.A
| | | | | | - Martin D. Brand
- Department of Biological and Pharmaceutical Sciences, Touro University California College of Pharmacy, Vallejo, CA, U.S.A
- Buck Institute for Research on Aging, Novato, CA, U.S.A
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8
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Amodeo GF, Krilyuk N, Pavlov EV. Formation of High-Conductive C Subunit Channels upon Interaction with Cyclophilin D. Int J Mol Sci 2021; 22:ijms222011022. [PMID: 34681682 PMCID: PMC8538490 DOI: 10.3390/ijms222011022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/05/2021] [Accepted: 10/10/2021] [Indexed: 12/25/2022] Open
Abstract
The c subunit of the ATP synthase is an inner mitochondrial membrane (IMM) protein. Besides its role as the main component of the rotor of the ATP synthase, c subunit from mammalian mitochondria exhibits ion channel activity. In particular, c subunit may be involved in one of the pathways leading to the formation of the permeability transition pore (PTP) during mitochondrial permeability transition (PT), a phenomenon consisting of the permeabilization of the IMM due to high levels of calcium. Our previous study on the synthetic c subunit showed that high concentrations of calcium induce misfolding into cross-β oligomers that form low-conductance channels in model lipid bilayers of about 400 pS. Here, we studied the effect of cyclophilin D (CypD), a mitochondrial chaperone and major regulator of PTP, on the electrophysiological activity of the c subunit to evaluate its role in the functional properties of c subunit. Our study shows that in presence of CypD, c subunit exhibits a larger conductance, up to 4 nS, that could be related to its potential role in mitochondrial toxicity. Further, our results suggest that CypD is necessary for the formation of c subunit induced PTP but may not be an integral part of the pore.
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9
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Aksu-Menges E, Eylem CC, Nemutlu E, Gizer M, Korkusuz P, Topaloglu H, Talim B, Balci-Hayta B. Reduced mitochondrial fission and impaired energy metabolism in human primary skeletal muscle cells of Megaconial Congenital Muscular Dystrophy. Sci Rep 2021; 11:18161. [PMID: 34518586 PMCID: PMC8438035 DOI: 10.1038/s41598-021-97294-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 08/13/2021] [Indexed: 11/09/2022] Open
Abstract
Megaconial Congenital Muscular Dystrophy (CMD) is a rare autosomal recessive disorder characterized by enlarged mitochondria located mainly at the periphery of muscle fibers and caused by mutations in the Choline Kinase Beta (CHKB) gene. Although the pathogenesis of this disease is not well understood, there is accumulating evidence for the presence of mitochondrial dysfunction. In this study, we aimed to investigate whether imbalanced mitochondrial dynamics affects mitochondrial function and bioenergetic efficiency in skeletal muscle cells of Megaconial CMD. Immunofluorescence, confocal and transmission electron microscopy studies revealed impaired mitochondrial network, morphology, and localization in primary skeletal muscle cells of Megaconial CMD. The organelle disruption was specific only to skeletal muscle cells grown in culture. The expression levels of mitochondrial fission proteins (DRP1, MFF, FIS1) were found to be decreased significantly in both primary skeletal muscle cells and tissue sections of Megaconial CMD by Western blotting and/or immunofluorescence analysis. The metabolomic and fluxomic analysis, which were performed in Megaconial CMD for the first time, revealed decreased levels of phosphonucleotides, Krebs cycle intermediates, ATP, and altered energy metabolism pathways. Our results indicate that reduced mitochondrial fission and altered mitochondrial energy metabolism contribute to mitochondrial dysmorphology and dysfunction in the pathogenesis of Megaconial CMD.
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Affiliation(s)
- Evrim Aksu-Menges
- Department of Medical Biology, Faculty of Medicine, Hacettepe University, 06100, Sihhiye, Ankara, Turkey
| | - Cemil Can Eylem
- Department of Analytical Chemistry, Faculty of Pharmacy, Hacettepe University, 06100, Sihhiye, Ankara, Turkey
| | - Emirhan Nemutlu
- Department of Analytical Chemistry, Faculty of Pharmacy, Hacettepe University, 06100, Sihhiye, Ankara, Turkey
| | - Merve Gizer
- Department of Stem Cell Sciences, Graduate School of Health Sciences, Hacettepe University, 06100, Sihhiye, Ankara, Turkey
| | - Petek Korkusuz
- Department of Histology and Embryology, Faculty of Medicine, Hacettepe University, 06100, Sihhiye, Ankara, Turkey
| | - Haluk Topaloglu
- Department of Pediatrics, Division of Child Neurology, Faculty of Medicine, Hacettepe University, 06100, Sihhiye, Ankara, Turkey.,Department of Pediatrics, Yeditepe University, Istanbul, Turkey
| | - Beril Talim
- Department of Pediatrics, Pathology Unit, Faculty of Medicine, Hacettepe University, 06100, Sihhiye, Ankara, Turkey
| | - Burcu Balci-Hayta
- Department of Medical Biology, Faculty of Medicine, Hacettepe University, 06100, Sihhiye, Ankara, Turkey.
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10
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Afzal N, Lederer WJ, Jafri MS, Mannella CA. Effect of crista morphology on mitochondrial ATP output: A computational study. Curr Res Physiol 2021; 4:163-176. [PMID: 34396153 PMCID: PMC8360328 DOI: 10.1016/j.crphys.2021.03.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Folding of the mitochondrial inner membrane (IM) into cristae greatly increases the ATP-generating surface area, S IM, per unit volume but also creates diffusional bottlenecks that could limit reaction rates inside mitochondria. This study explores possible effects of inner membrane folding on mitochondrial ATP output, using a mathematical model for energy metabolism developed by the Jafri group and two- and three-dimensional spatial models for mitochondria, implemented on the Virtual Cell platform. Simulations demonstrate that cristae are micro-compartments functionally distinct from the cytosol. At physiological steady states, standing gradients of ADP form inside cristae that depend on the size and shape of the compartments, and reduce local flux (rate per unit area) of the adenine nucleotide translocase. This causes matrix ADP levels to drop, which in turn reduces the flux of ATP synthase. The adverse effects of membrane folding on reaction fluxes increase with crista length and are greater for lamellar than tubular crista. However, total ATP output per mitochondrion is the product of flux of ATP synthase and S IM which can be two-fold greater for mitochondria with lamellar than tubular cristae, resulting in greater ATP output for the former. The simulations also demonstrate the crucial role played by intracristal kinases (adenylate kinase, creatine kinase) in maintaining the energy advantage of IM folding.
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Affiliation(s)
- Nasrin Afzal
- Krasnow Institute for Advanced Study and School of Systems Biology, George Mason University, Fairfax, VA, 22030, USA
| | - W Jonathan Lederer
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.,Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - M Saleet Jafri
- Krasnow Institute for Advanced Study and School of Systems Biology, George Mason University, Fairfax, VA, 22030, USA.,Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Carmen A Mannella
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.,Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
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11
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Functional activity of permeability transition pore in energized and deenergized rat liver mitochondria. UKRAINIAN BIOCHEMICAL JOURNAL 2020. [DOI: 10.15407/ubj92.06.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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12
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Neginskaya MA, Strubbe JO, Amodeo GF, West BA, Yakar S, Bazil JN, Pavlov EV. The very low number of calcium-induced permeability transition pores in the single mitochondrion. J Gen Physiol 2020; 152:e202012631. [PMID: 32810269 PMCID: PMC7537349 DOI: 10.1085/jgp.202012631] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 06/22/2020] [Accepted: 07/24/2020] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial permeability transition (PT) is a phenomenon of stress-induced increase in nonspecific permeability of the mitochondrial inner membrane that leads to disruption of oxidative phosphorylation and cell death. Quantitative measurement of the membrane permeability increase during PT is critically important for understanding the PT's impact on mitochondrial function. The elementary unit of PT is a PT pore (PTP), a single channel presumably formed by either ATP synthase or adenine nucleotide translocator (ANT). It is not known how many channels are open in a single mitochondrion during PT, which makes it difficult to quantitatively estimate the overall degree of membrane permeability. Here, we used wide-field microscopy to record mitochondrial swelling and quantitatively measure rates of single-mitochondrion volume increase during PT-induced high-amplitude swelling. PT was quantified by calculating the rates of water flux responsible for measured volume changes. The total water flux through the mitochondrial membrane of a single mitochondrion during PT was in the range of (2.5 ± 0.4) × 10-17 kg/s for swelling in 2 mM Ca2+ and (1.1 ± 0.2) × 10-17 kg/s for swelling in 200 µM Ca2+. Under these experimental conditions, a single PTP channel with ionic conductance of 1.5 nS could allow passage of water at the rate of 0.65 × 10-17 kg/s. Thus, we estimate the integral ionic conductance of the whole mitochondrion during PT to be 5.9 ± 0.9 nS for 2 mM concentration of Ca2+ and 2.6 ± 0.4 nS for 200 µM of Ca2+. The number of PTPs per mitochondrion ranged from one to nine. Due to the uncertainties in PTP structure and model parameters, PTP count results may be slightly underestimated. However, taking into account that each mitochondrion has ∼15,000 copies of ATP synthases and ANTs, our data imply that PTP activation is a rare event that occurs only in a small subpopulation of these proteins.
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Affiliation(s)
- Maria A. Neginskaya
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY
| | - Jasiel O. Strubbe
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI
- Department of Physiology, Michigan State University, East Lansing, MI
| | - Giuseppe F. Amodeo
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY
| | - Benjamin A. West
- Department of Physiology, Michigan State University, East Lansing, MI
| | - Shoshana Yakar
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY
| | - Jason N. Bazil
- Department of Physiology, Michigan State University, East Lansing, MI
| | - Evgeny V. Pavlov
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, NY
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13
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Jadiya P, Tomar D. Mitochondrial Protein Quality Control Mechanisms. Genes (Basel) 2020; 11:genes11050563. [PMID: 32443488 PMCID: PMC7290828 DOI: 10.3390/genes11050563] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 05/14/2020] [Accepted: 05/15/2020] [Indexed: 02/08/2023] Open
Abstract
Mitochondria serve as a hub for many cellular processes, including bioenergetics, metabolism, cellular signaling, redox balance, calcium homeostasis, and cell death. The mitochondrial proteome includes over a thousand proteins, encoded by both the mitochondrial and nuclear genomes. The majority (~99%) of proteins are nuclear encoded that are synthesized in the cytosol and subsequently imported into the mitochondria. Within the mitochondria, polypeptides fold and assemble into their native functional form. Mitochondria health and integrity depend on correct protein import, folding, and regulated turnover termed as mitochondrial protein quality control (MPQC). Failure to maintain these processes can cause mitochondrial dysfunction that leads to various pathophysiological outcomes and the commencement of diseases. Here, we summarize the current knowledge about the role of different MPQC regulatory systems such as mitochondrial chaperones, proteases, the ubiquitin-proteasome system, mitochondrial unfolded protein response, mitophagy, and mitochondria-derived vesicles in the maintenance of mitochondrial proteome and health. The proper understanding of mitochondrial protein quality control mechanisms will provide relevant insights to treat multiple human diseases.
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Affiliation(s)
- Pooja Jadiya
- Correspondence: (P.J.); (D.T.); Tel.: +1-215-707-9144 (D.T.)
| | - Dhanendra Tomar
- Correspondence: (P.J.); (D.T.); Tel.: +1-215-707-9144 (D.T.)
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14
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Rose JJ, Bocian KA, Xu Q, Wang L, DeMartino AW, Chen X, Corey CG, Guimarães DA, Azarov I, Huang XN, Tong Q, Guo L, Nouraie M, McTiernan CF, O'Donnell CP, Tejero J, Shiva S, Gladwin MT. A neuroglobin-based high-affinity ligand trap reverses carbon monoxide-induced mitochondrial poisoning. J Biol Chem 2020; 295:6357-6371. [PMID: 32205448 PMCID: PMC7212636 DOI: 10.1074/jbc.ra119.010593] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 03/16/2020] [Indexed: 12/18/2022] Open
Abstract
Carbon monoxide (CO) remains the most common cause of human poisoning. The consequences of CO poisoning include cardiac dysfunction, brain injury, and death. CO causes toxicity by binding to hemoglobin and by inhibiting mitochondrial cytochrome c oxidase (CcO), thereby decreasing oxygen delivery and inhibiting oxidative phosphorylation. We have recently developed a CO antidote based on human neuroglobin (Ngb-H64Q-CCC). This molecule enhances clearance of CO from red blood cells in vitro and in vivo Herein, we tested whether Ngb-H64Q-CCC can also scavenge CO from CcO and attenuate CO-induced inhibition of mitochondrial respiration. Heart tissue from mice exposed to 3% CO exhibited a 42 ± 19% reduction in tissue respiration rate and a 33 ± 38% reduction in CcO activity compared with unexposed mice. Intravenous infusion of Ngb-H64Q-CCC restored respiration rates to that of control mice correlating with higher electron transport chain CcO activity in Ngb-H64Q-CCC-treated compared with PBS-treated, CO-poisoned mice. Further, using a Clark-type oxygen electrode, we measured isolated rat liver mitochondrial respiration in the presence and absence of saturating solutions of CO (160 μm) and nitric oxide (100 μm). Both CO and NO inhibited respiration, and treatment with Ngb-H64Q-CCC (100 and 50 μm, respectively) significantly reversed this inhibition. These results suggest that Ngb-H64Q-CCC mitigates CO toxicity by scavenging CO from carboxyhemoglobin, improving systemic oxygen delivery and reversing the inhibitory effects of CO on mitochondria. We conclude that Ngb-H64Q-CCC or other CO scavengers demonstrate potential as antidotes that reverse the clinical and molecular effects of CO poisoning.
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Affiliation(s)
- Jason J Rose
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213
- Department of Bioengineering, University of Pittsburgh Swanson School of Engineering, Pittsburgh, Pennsylvania 15261
| | - Kaitlin A Bocian
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213
| | - Qinzi Xu
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213
| | - Ling Wang
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213
| | - Anthony W DeMartino
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213
| | - Xiukai Chen
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213
| | - Catherine G Corey
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213
| | - Danielle A Guimarães
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213
| | - Ivan Azarov
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213
| | - Xueyin N Huang
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213
| | - Qin Tong
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213
| | - Lanping Guo
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213
| | - Mehdi Nouraie
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213
| | - Charles F McTiernan
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213
| | - Christopher P O'Donnell
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213
| | - Jesús Tejero
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213
- Department of Bioengineering, University of Pittsburgh Swanson School of Engineering, Pittsburgh, Pennsylvania 15261
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213
| | - Sruti Shiva
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213
| | - Mark T Gladwin
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213
- Department of Bioengineering, University of Pittsburgh Swanson School of Engineering, Pittsburgh, Pennsylvania 15261
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15
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Kawamura E, Maruyama M, Abe J, Sudo A, Takeda A, Takada S, Yokota T, Kinugawa S, Harashima H, Yamada Y. Validation of Gene Therapy for Mutant Mitochondria by Delivering Mitochondrial RNA Using a MITO-Porter. MOLECULAR THERAPY. NUCLEIC ACIDS 2020; 20:687-698. [PMID: 32388194 PMCID: PMC7210581 DOI: 10.1016/j.omtn.2020.04.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 04/10/2020] [Accepted: 04/15/2020] [Indexed: 10/29/2022]
Abstract
Here, we report on validating a mitochondrial gene therapy by delivering nucleic acids to mitochondria of diseased cells by a MITO-Porter, a liposome-based carrier for mitochondrial delivery. We used cells derived from a patient with a mitochondrial disease with a G625A heteroplasmic mutation in the tRNAPhe of the mitochondrial DNA (mtDNA). It has been reported that some mitochondrial gene diseases are caused by heteroplasmic mutations, in which both mutated and wild-type (WT) genes are present, and the accumulation of pathological mutations leads to serious, intractable, multi-organ diseases. Therefore, the decrease of the mutated gene rate is considered to be a useful gene therapy strategy. To accomplish this, wild-type mitochondrial pre-tRNAPhe (pre-WT-tRNAPhe), prepared by in vitro transcription, was encapsulated in the MITO-Porter. The pre-WT-tRNAPhe encapsulated in the MITO-Porter was transfected into diseased mitochondrial cells, and the resulting mutant levels were examined by an amplification refractory mutation system (ARMS)-quantitative PCR. The mutation rate of tRNAPhe was decreased, and this therapeutic effect was sustained even on the 8th day after transfection. Furthermore, mitochondrial respiratory activity of the disease cells was increased after the transfection of therapeutic pre-WT-tRNAPhe. These results support the conclusion that the mitochondrial delivery of therapeutic nucleic acids represents a viable strategy for mitochondrial gene therapy.
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Affiliation(s)
- Eriko Kawamura
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan
| | - Minako Maruyama
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan
| | - Jiro Abe
- Department of Pediatrics, Hokkaido University Hospital, Kita-15, Nishi-7, Kita-ku, Sapporo 060-8638, Japan
| | - Akira Sudo
- Nire-no-kai Children's Clinic, Atsubetsu-cho Shimonopporo-49, Atsubetsu-ku, Sapporo 004-0007, Japan; Department of Pediatrics, Sapporo City General Hospital, Kita-11, Nishi-13, Chuo-ku, Sapporo 060-8604, Japan
| | - Atsuhito Takeda
- Department of Pediatrics, Hokkaido University Hospital, Kita-15, Nishi-7, Kita-ku, Sapporo 060-8638, Japan
| | - Shingo Takada
- Department of Cardiovascular Medicine, Graduate School of Medicine, Hokkaido University, Kita-15, Nishi-7, Kita-ku, Sapporo 060-8638, Japan
| | - Takashi Yokota
- Department of Cardiovascular Medicine, Graduate School of Medicine, Hokkaido University, Kita-15, Nishi-7, Kita-ku, Sapporo 060-8638, Japan
| | - Shintaro Kinugawa
- Department of Cardiovascular Medicine, Graduate School of Medicine, Hokkaido University, Kita-15, Nishi-7, Kita-ku, Sapporo 060-8638, Japan
| | - Hideyoshi Harashima
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan
| | - Yuma Yamada
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan.
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16
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Kinetic advantage of forming respiratory supercomplexes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148193. [PMID: 32201307 DOI: 10.1016/j.bbabio.2020.148193] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/11/2020] [Accepted: 03/16/2020] [Indexed: 11/22/2022]
Abstract
Components of respiratory chains in mitochondria and some aerobic bacteria assemble into larger, multiprotein membrane-bound supercomplexes. Here, we address the functional significance of supercomplexes composed of respiratory-chain complexes III and IV. Complex III catalyzes oxidation of quinol and reduction of water-soluble cytochrome c (cyt c), while complex IV catalyzes oxidation of the reduced cyt c and reduction of dioxygen to water. We focus on two questions: (i) under which conditions does diffusion of cyt c become rate limiting for electron transfer between these two complexes? (ii) is there a kinetic advantage of forming a supercomplex composed of complexes III and IV? To answer these questions, we use a theoretical approach and assume that cyt c diffuses in the water phase while complexes III and IV either diffuse independently in the two dimensions of the membrane or form supercomplexes. The analysis shows that the electron flux between complexes III and IV is determined by the equilibration time of cyt c within the volume of the intermembrane space, rather than the cyt c diffusion time constant. Assuming realistic relative concentrations of membrane-bound components and cyt c and that all components diffuse independently, the data indicate that electron transfer between complexes III and IV can become rate limiting. Hence, there is a kinetic advantage of bringing complexes III and IV together in the membrane to form supercomplexes.
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17
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Manoj KM, Ramasamy S, Parashar A, Gideon DA, Soman V, Jacob VD, Pakshirajan K. Acute toxicity of cyanide in aerobic respiration: Theoretical and experimental support for murburn explanation. Biomol Concepts 2020; 11:32-56. [PMID: 32187011 DOI: 10.1515/bmc-2020-0004] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 02/19/2020] [Indexed: 12/30/2022] Open
Abstract
The inefficiency of cyanide/HCN (CN) binding with heme proteins (under physiological regimes) is demonstrated with an assessment of thermodynamics, kinetics, and inhibition constants. The acute onset of toxicity and CN's mg/Kg LD50 (μM lethal concentration) suggests that the classical hemeFe binding-based inhibition rationale is untenable to account for the toxicity of CN. In vitro mechanistic probing of CN-mediated inhibition of hemeFe reductionist systems was explored as a murburn model for mitochondrial oxidative phosphorylation (mOxPhos). The effect of CN in haloperoxidase catalyzed chlorine moiety transfer to small organics was considered as an analogous probe for phosphate group transfer in mOxPhos. Similarly, inclusion of CN in peroxidase-catalase mediated one-electron oxidation of small organics was used to explore electron transfer outcomes in mOxPhos, leading to water formation. The free energy correlations from a Hammett study and IC50/Hill slopes analyses and comparison with ligands ( CO/ H 2 S/ N 3 - ) $\left( {\text{CO}}/{{{{\text{H}}_{2}}\text{S}}/{\text{N}_{3}^{\text{-}}}\;}\; \right)$ provide insights into the involvement of diffusible radicals and proton-equilibriums, explaining analogous outcomes in mOxPhos chemistry. Further, we demonstrate that superoxide (diffusible reactive oxygen species, DROS) enables in vitro ATP synthesis from ADP+phosphate, and show that this reaction is inhibited by CN. Therefore, practically instantaneous CN ion-radical interactions with DROS in matrix catalytically disrupt mOxPhos, explaining the acute lethal effect of CN.
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Affiliation(s)
- Kelath Murali Manoj
- Satyamjayatu: The Science & Ethics Foundation Snehatheeram, Kulappully, Shoranur-2 (PO), Kerala, India-679122
| | - Surjith Ramasamy
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India-781039
| | - Abhinav Parashar
- Department of Biotechnology, Vignan's Foundation for Science, Technology & Research, Vadlamudi, Guntur, India-522213
| | - Daniel Andrew Gideon
- Department of Biotechnology, Bishop Heber College, Tiruchirappalli, Tamil Nadu, India-620017
| | - Vidhu Soman
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi, India-110016
| | - Vivian David Jacob
- Satyamjayatu: The Science & Ethics Foundation Snehatheeram, Kulappully, Shoranur-2 (PO), Kerala, India-679122
| | - Kannan Pakshirajan
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India-781039
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18
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Manoj KM, Soman V. Classical and murburn explanations for acute toxicity of cyanide in aerobic respiration: A personal perspective. Toxicology 2020; 432:152369. [PMID: 32007488 DOI: 10.1016/j.tox.2020.152369] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 01/09/2020] [Accepted: 01/14/2020] [Indexed: 01/15/2023]
Affiliation(s)
- Kelath Murali Manoj
- Satyamjayatu: The Science & Ethics Foundation, Snehatheeram, Kulappully, Shoranur-2 (PO), Kerala, 679122, India.
| | - Vidhu Soman
- Satyamjayatu: The Science & Ethics Foundation, Snehatheeram, Kulappully, Shoranur-2 (PO), Kerala, 679122, India
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19
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Fuchs P, Rugen N, Carrie C, Elsässer M, Finkemeier I, Giese J, Hildebrandt TM, Kühn K, Maurino VG, Ruberti C, Schallenberg-Rüdinger M, Steinbeck J, Braun HP, Eubel H, Meyer EH, Müller-Schüssele SJ, Schwarzländer M. Single organelle function and organization as estimated from Arabidopsis mitochondrial proteomics. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 101:420-441. [PMID: 31520498 DOI: 10.1111/tpj.14534] [Citation(s) in RCA: 107] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 08/23/2019] [Accepted: 08/28/2019] [Indexed: 05/14/2023]
Abstract
Mitochondria host vital cellular functions, including oxidative phosphorylation and co-factor biosynthesis, which are reflected in their proteome. At the cellular level plant mitochondria are organized into hundreds of discrete functional entities, which undergo dynamic fission and fusion. It is the individual organelle that operates in the living cell, yet biochemical and physiological assessments have exclusively focused on the characteristics of large populations of mitochondria. Here, we explore the protein composition of an individual average plant mitochondrion to deduce principles of functional and structural organisation. We perform proteomics on purified mitochondria from cultured heterotrophic Arabidopsis cells with intensity-based absolute quantification and scale the dataset to the single organelle based on criteria that are justified by experimental evidence and theoretical considerations. We estimate that a total of 1.4 million protein molecules make up a single Arabidopsis mitochondrion on average. Copy numbers of the individual proteins span five orders of magnitude, ranging from >40 000 for Voltage-Dependent Anion Channel 1 to sub-stoichiometric copy numbers, i.e. less than a single copy per single mitochondrion, for several pentatricopeptide repeat proteins that modify mitochondrial transcripts. For our analysis, we consider the physical and chemical constraints of the single organelle and discuss prominent features of mitochondrial architecture, protein biogenesis, oxidative phosphorylation, metabolism, antioxidant defence, genome maintenance, gene expression, and dynamics. While assessing the limitations of our considerations, we exemplify how our understanding of biochemical function and structural organization of plant mitochondria can be connected in order to obtain global and specific insights into how organelles work.
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Affiliation(s)
- Philippe Fuchs
- Institut für Biologie und Biotechnologie der Pflanzen (IBBP), Westfälische Wilhelms-Universität, Schlossplatz 7-8, 48143, Münster, Germany
- Institut für Nutzpflanzenforschung und Ressourcenschutz (INRES), Rheinische Friedrich-Wilhelms-Universität Bonn, Friedrich-Ebert-Allee 144, 53113, Bonn, Germany
| | - Nils Rugen
- Institut für Pflanzengenetik, Leibniz Universität Hannover, Herrenhäuser Str. 2, 30419, Hannover, Germany
| | - Chris Carrie
- Department Biologie I - Botanik, Ludwig-Maximilians-Universität München, Grosshadernerstr. 2-4, 82152, Planegg-Martinsried, Germany
| | - Marlene Elsässer
- Institut für Biologie und Biotechnologie der Pflanzen (IBBP), Westfälische Wilhelms-Universität, Schlossplatz 7-8, 48143, Münster, Germany
- Institut für Nutzpflanzenforschung und Ressourcenschutz (INRES), Rheinische Friedrich-Wilhelms-Universität Bonn, Friedrich-Ebert-Allee 144, 53113, Bonn, Germany
- Institut für Zelluläre und Molekulare Botanik (IZMB), Rheinische Friedrich-Wilhelms-Universität Bonn, Kirschallee 1, 53115, Bonn, Germany
| | - Iris Finkemeier
- Institut für Biologie und Biotechnologie der Pflanzen (IBBP), Westfälische Wilhelms-Universität, Schlossplatz 7-8, 48143, Münster, Germany
| | - Jonas Giese
- Institut für Biologie und Biotechnologie der Pflanzen (IBBP), Westfälische Wilhelms-Universität, Schlossplatz 7-8, 48143, Münster, Germany
| | - Tatjana M Hildebrandt
- Institut für Pflanzengenetik, Leibniz Universität Hannover, Herrenhäuser Str. 2, 30419, Hannover, Germany
| | - Kristina Kühn
- Institut für Biologie, Martin-Luther-Universität Halle-Wittenberg, Weinbergweg 10, 06120, Halle/Saale, Germany
| | - Veronica G Maurino
- Institute of Developmental and Molecular Biology of Plants, and Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Cristina Ruberti
- Institut für Biologie und Biotechnologie der Pflanzen (IBBP), Westfälische Wilhelms-Universität, Schlossplatz 7-8, 48143, Münster, Germany
| | - Mareike Schallenberg-Rüdinger
- Institut für Zelluläre und Molekulare Botanik (IZMB), Rheinische Friedrich-Wilhelms-Universität Bonn, Kirschallee 1, 53115, Bonn, Germany
| | - Janina Steinbeck
- Institut für Biologie und Biotechnologie der Pflanzen (IBBP), Westfälische Wilhelms-Universität, Schlossplatz 7-8, 48143, Münster, Germany
| | - Hans-Peter Braun
- Institut für Pflanzengenetik, Leibniz Universität Hannover, Herrenhäuser Str. 2, 30419, Hannover, Germany
| | - Holger Eubel
- Institut für Pflanzengenetik, Leibniz Universität Hannover, Herrenhäuser Str. 2, 30419, Hannover, Germany
| | - Etienne H Meyer
- Institut für Biologie, Martin-Luther-Universität Halle-Wittenberg, Weinbergweg 10, 06120, Halle/Saale, Germany
| | - Stefanie J Müller-Schüssele
- Institut für Nutzpflanzenforschung und Ressourcenschutz (INRES), Rheinische Friedrich-Wilhelms-Universität Bonn, Friedrich-Ebert-Allee 144, 53113, Bonn, Germany
| | - Markus Schwarzländer
- Institut für Biologie und Biotechnologie der Pflanzen (IBBP), Westfälische Wilhelms-Universität, Schlossplatz 7-8, 48143, Münster, Germany
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20
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Mitochondrial morphology provides a mechanism for energy buffering at synapses. Sci Rep 2019; 9:18306. [PMID: 31797946 PMCID: PMC6893035 DOI: 10.1038/s41598-019-54159-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 10/24/2019] [Indexed: 01/27/2023] Open
Abstract
Mitochondria as the main energy suppliers of eukaryotic cells are highly dynamic organelles that fuse, divide and are transported along the cytoskeleton to ensure cellular energy homeostasis. While these processes are well established, substantial evidence indicates that the internal structure is also highly variable in dependence on metabolic conditions. However, a quantitative mechanistic understanding of how mitochondrial morphology affects energetic states is still elusive. To address this question, we here present an agent-based multiscale model that integrates three-dimensional morphologies from electron microscopy tomography with the molecular dynamics of the main ATP producing components. We apply our modeling approach to mitochondria at the synapse which is the largest energy consumer within the brain. Interestingly, comparing the spatiotemporal simulations with a corresponding space-independent approach, we find minor spatial effects when the system relaxes toward equilibrium but a qualitative difference in fluctuating environments. These results suggest that internal mitochondrial morphology is not only optimized for ATP production but also provides a mechanism for energy buffering and may represent a mechanism for cellular robustness.
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21
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Manoj KM, Soman V, David Jacob V, Parashar A, Gideon DA, Kumar M, Manekkathodi A, Ramasamy S, Pakshirajan K, Bazhin NM. Chemiosmotic and murburn explanations for aerobic respiration: Predictive capabilities, structure-function correlations and chemico-physical logic. Arch Biochem Biophys 2019; 676:108128. [PMID: 31622585 DOI: 10.1016/j.abb.2019.108128] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 10/03/2019] [Accepted: 10/04/2019] [Indexed: 12/18/2022]
Abstract
Since mid-1970s, the proton-centric proposal of 'chemiosmosis' became the acclaimed explanation for aerobic respiration. Recently, significant theoretical and experimental evidence were presented for an oxygen-centric 'murburn' mechanism of mitochondrial ATP-synthesis. Herein, we compare the predictive capabilities of the two models with respect to the available information on mitochondrial reaction chemistry and the membrane proteins' structure-function correlations. Next, fundamental queries are addressed on thermodynamics of mitochondrial oxidative phosphorylation (mOxPhos): (1) Can the energy of oxygen reduction be utilized for proton transport? (2) Is the trans-membrane proton differential harness-able as a potential energy capable of doing useful work? and (3) Whether the movement of miniscule amounts of mitochondrial protons could give rise to a potential of ~200 mV and if such an electrical energy could sponsor ATP-synthesis. Further, we explore critically if rotary ATPsynthase activity of Complex V can account for physiological ATP-turnovers. We also answer the question- "What is the role of protons in the oxygen-centric murburn scheme of aerobic respiration?" Finally, it is demonstrated that the murburn reaction model explains the fast kinetics, non-integral stoichiometry and high yield of mOxPhos. Strategies are charted to further demarcate the two explanations' relevance in the cellular physiology of aerobic respiration.
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Affiliation(s)
- Kelath Murali Manoj
- Satyamjayatu: The Science & Ethics Foundation, Snehatheeram, Kulappully, Shoranur-2 (PO), Kerala, 679122, India.
| | - Vidhu Soman
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi, 110016, India
| | - Vivian David Jacob
- Satyamjayatu: The Science & Ethics Foundation, Snehatheeram, Kulappully, Shoranur-2 (PO), Kerala, 679122, India
| | - Abhinav Parashar
- Department of Biotechnology, Vignan's Foundation for Science, Technology & Research, Vadlamudi, Guntur, 522213, India
| | - Daniel Andrew Gideon
- Department of Biotechnology & Bioinformatics, Bishop Heber College (Autonomous), Tennur, Tiruchirappalli, 620017, India
| | - Manish Kumar
- Satyamjayatu: The Science & Ethics Foundation, Snehatheeram, Kulappully, Shoranur-2 (PO), Kerala, 679122, India
| | - Afsal Manekkathodi
- Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Al-Rayyan PO Box 34110, Qatar
| | - Surjith Ramasamy
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India
| | - Kannan Pakshirajan
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India
| | - Nikolai Mikhailovich Bazhin
- Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, St. Institutskaya 3, 630090, Novosibirsk, Russia.
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22
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Schneider S, Harant D, Bachmann G, Nägele T, Lang I, Wienkoop S. Subcellular Phenotyping: Using Proteomics to Quantitatively Link Subcellular Leaf Protein and Organelle Distribution Analyses of Pisum sativum Cultivars. FRONTIERS IN PLANT SCIENCE 2019; 10:638. [PMID: 31191569 PMCID: PMC6534152 DOI: 10.3389/fpls.2019.00638] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 04/29/2019] [Indexed: 06/09/2023]
Abstract
Plant phenotyping to date typically comprises morphological and physiological profiling in a high-throughput manner. A powerful method that allows for subcellular characterization of organelle stoichiometric/functional characteristics is still missing. Organelle abundance and crosstalk in cell dynamics and signaling plays an important role for understanding crop growth and stress adaptations. However, microscopy cannot be considered a high-throughput technology. The aim of the present study was to develop an approach that enables the estimation of organelle functional stoichiometry and to determine differential subcellular dynamics within and across cultivars in a high-throughput manner. A combination of subcellular non-aqueous fractionation and liquid chromatography mass spectrometry was applied to assign membrane-marker proteins to cell compartmental abundances and functions of Pisum sativum leaves. Based on specific subcellular affiliation, proteotypic marker peptides of the chloroplast, mitochondria and vacuole membranes were selected and synthesized as heavy isotope labeled standards. The rapid and unbiased Mass Western approach for accurate stoichiometry and targeted absolute protein quantification allowed for a proportional organelle abundances measure linked to their functional properties. A 3D Confocal Laser Scanning Microscopy approach was developed to evaluate the Mass Western. Two P. sativum cultivars of varying morphology and physiology were compared. The Mass Western assay enabled a cultivar specific discrimination of the chloroplast to mitochondria to vacuole relations.
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Affiliation(s)
- Sebastian Schneider
- Division of Molecular Systems Biology, Department of Ecogenomics and Systems Biology, University of Vienna, Vienna, Austria
| | - Dominik Harant
- Core Facility Cell Imaging and Ultrastructure Research, University of Vienna, Vienna, Austria
| | - Gert Bachmann
- Division of Molecular Systems Biology, Department of Ecogenomics and Systems Biology, University of Vienna, Vienna, Austria
| | - Thomas Nägele
- Division of Molecular Systems Biology, Department of Ecogenomics and Systems Biology, University of Vienna, Vienna, Austria
- Department Biology I, Plant Evolutionary Cell Biology, Ludwig-Maximilians Universität, Munich, Germany
| | - Ingeborg Lang
- Core Facility Cell Imaging and Ultrastructure Research, University of Vienna, Vienna, Austria
| | - Stefanie Wienkoop
- Division of Molecular Systems Biology, Department of Ecogenomics and Systems Biology, University of Vienna, Vienna, Austria
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23
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Manoj KM. Aerobic Respiration: Criticism of the Proton-centric Explanation Involving Rotary Adenosine Triphosphate Synthesis, Chemiosmosis Principle, Proton Pumps and Electron Transport Chain. BIOCHEMISTRY INSIGHTS 2018; 11:1178626418818442. [PMID: 30643418 PMCID: PMC6311555 DOI: 10.1177/1178626418818442] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 11/20/2018] [Indexed: 12/17/2022]
Abstract
The acclaimed explanation for mitochondrial oxidative phosphorylation (mOxPhos, or cellular respiration) is a deterministic proton-centric scheme involving four components: Rotary adenosine triphosphate (ATP)-synthesis, Chemiosmosis principle, Proton pumps, and Electron transport chain (abbreviated as RCPE hypothesis). Within this write-up, the RCPE scheme is critically analyzed with respect to mitochondrial architecture, proteins’ distribution, structure-function correlations and their interactive dynamics, overall reaction chemistry, kinetics, thermodynamics, evolutionary logic, and so on. It is found that the RCPE proposal fails to explain key physiological aspects of mOxPhos in several specific issues and also in holistic perspectives. Therefore, it is imperative to look for new explanations for mOxPhos.
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24
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Zischka H, Einer C. Mitochondrial copper homeostasis and its derailment in Wilson disease. Int J Biochem Cell Biol 2018; 102:71-75. [PMID: 29997057 DOI: 10.1016/j.biocel.2018.07.001] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 06/29/2018] [Accepted: 07/03/2018] [Indexed: 01/07/2023]
Abstract
In mitochondria, copper is a Janus-faced trace element. While it is the essential cofactor of the mitochondrial cytochrome c oxidase, a surplus of copper can be highly detrimental to these organelles. On the one hand, mitochondria are strictly dependent on adequate copper supply for proper respiratory function, and the molecular mechanisms for metalation of the cytochrome c oxidase have been largely characterized. On the other hand, copper overload impairs mitochondria and uncertainties exist concerning the molecular mechanisms for mitochondrial metal uptake, storage and release. The latter issue is of fundamental importance in Wilson disease, a genetic disease characterized by dysfunctional copper excretion from the liver. Prime consequences of the progressive copper accumulation in hepatocytes are increasing mitochondrial biophysical and biochemical deficits. Focusing on this two-sided aspect of mitochondrial copper, we review mitochondrial copper homeostasis but also the impact of excessive mitochondrial copper in Wilson disease.
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Affiliation(s)
- Hans Zischka
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Center Munich, German Research Center for Environmental Health, 85764 Neuherberg, Germany; Institute of Toxicology and Environmental Hygiene, Technical University of Munich, 80802 Munich, Germany.
| | - Claudia Einer
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Center Munich, German Research Center for Environmental Health, 85764 Neuherberg, Germany
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25
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Analysis of a Functional Dimer Model of Ubiquinol Cytochrome c Oxidoreductase. Biophys J 2017; 113:1599-1612. [PMID: 28978450 PMCID: PMC5627346 DOI: 10.1016/j.bpj.2017.08.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 08/04/2017] [Accepted: 08/10/2017] [Indexed: 11/21/2022] Open
Abstract
Ubiquinol cytochrome c oxidoreductase (bc1 complex) serves as an important electron junction in many respiratory systems. It funnels electrons coming from NADH and ubiquinol to cytochrome c, but it is also capable of producing significant amounts of the free radical superoxide. In situ and in other experimental systems, the enzyme exists as a dimer. But until recently, it was believed to operate as a functional monomer. Here we show that a functional dimer model is capable of explaining both kinetic and superoxide production rate data. The model consists of six electronic states characterized by the number of electrons deposited on the complex. It is fully reversible and strictly adheres to the thermodynamics governing the reactions. A total of nine independent data sets were used to parameterize the model. To explain the data with a consistent set of parameters, it was necessary to incorporate intramonomer Coulombic effects between hemes bL and bH and intermonomer Coulombic effects between bL hemes. The fitted repulsion energies fall within the theoretical range of electrostatic calculations. In addition, model analysis demonstrates that the Q pool is mostly oxidized under normal physiological operation but can switch to a more reduced state when reverse electron transport conditions are in place.
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26
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Why Do Fast-Growing Bacteria Enter Overflow Metabolism? Testing the Membrane Real Estate Hypothesis. Cell Syst 2017; 5:95-104. [PMID: 28755958 DOI: 10.1016/j.cels.2017.06.005] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 04/13/2017] [Accepted: 06/09/2017] [Indexed: 11/22/2022]
Abstract
Bacteria and other cells show a puzzling behavior. At high growth rates, E. coli switch from respiration (which is ATP-efficient) to using fermentation for additional ATP (which is inefficient). This overflow metabolism results in a several-fold decrease in ATP produced per glucose molecule provided as food. By integrating diverse types of experimental data into a simple biophysical model, we give evidence that this onset is the result of the membrane real estate hypothesis: Fast growth drives cells to be bigger, reducing their surface-to-volume ratios. This decreases the membrane area available for respiratory proteins despite growing demand, causing increased crowding. Only when respiratory proteins reach their crowding limit does the cell activate fermentation, since fermentation allows faster ATP production per unit membrane area. Surface limitation thus creates a Pareto trade-off between membrane efficiency and ATP yield that links metabolic choice to the size and shape of a bacterial cell. By exploring the predictions that emerge from this trade-off, we show how consideration of molecular structures, energetics, rates, and equilibria can provide important insight into cellular behavior.
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27
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Wang MM, Hao LY, Guo F, Zhong B, Zhong XM, Yuan J, Hao YF, Zhao S, Sun XF, Lei M, Jiao GY. Decreased intracellular [Ca 2+ ] coincides with reduced expression of Dhprα1s, RyR1, and diaphragmatic dysfunction in a rat model of sepsis. Muscle Nerve 2017; 56:1128-1136. [PMID: 28044347 DOI: 10.1002/mus.25554] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/30/2016] [Indexed: 12/23/2022]
Abstract
INTRODUCTION Sepsis can cause decreased diaphragmatic contractility. Intracellular calcium as a second messenger is central to diaphragmatic contractility. However, changes in intracellular calcium concentration ([Ca2+ ]) and the distribution and co-localization of relevant calcium channels [dihydropyridine receptors, (DHPRα1s) and ryanodine receptors (RyR1)] remain unclear during sepsis. In this study we investigated the effect of changed intracellular [Ca2+ ] and expression and distribution of DHPRα1s and RyR1 on diaphragm function during sepsis. METHODS We measured diaphragm contractility and isolated diaphragm muscle cells in a rat model of sepsis. The distribution and co-localization of DHPRα1s and RyR1 were determined using immunohistochemistry and immunofluorescence, whereas intracellular [Ca2+ ] was measured by confocal microscopy and fluorescence spectrophotometry. RESULTS Septic rat diaphragm contractility, expression of DHPRα1s and RyR1, and intracellular [Ca2+ ] were significantly decreased in the rat sepsis model compared with controls. DISCUSSION Decreased intracellular [Ca2+ ] coincides with diaphragmatic contractility and decreased expression of DHPRα1s and RyR1 in sepsis. Muscle Nerve 56: 1128-1136, 2017.
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Affiliation(s)
- Meng-Meng Wang
- Department of Respiratory and Intensive Care Unit, Shengjing Hospital of China Medical University, Shenyang, Postal Code 110004, People's Republic of China
| | - Li-Ying Hao
- Department of Pharmaceutical Toxicology, School of Pharmaceutical Sciences, China Medical University, Shenyang, People's Republic of China
| | - Feng Guo
- Department of Pharmaceutical Toxicology, School of Pharmaceutical Sciences, China Medical University, Shenyang, People's Republic of China
| | - Bin Zhong
- Department of Respiratory Medicine, The First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi Province, People's Republic of China
| | - Xiao-Mei Zhong
- Department of Respiratory and Intensive Care Unit, Shengjing Hospital of China Medical University, Shenyang, Postal Code 110004, People's Republic of China
| | - Jing Yuan
- Department of Respiratory and Intensive Care Unit, Shengjing Hospital of China Medical University, Shenyang, Postal Code 110004, People's Republic of China
| | - Yi-Fei Hao
- Department of Orthopedic Surgery, Shengjing Hospital of China Medical University, Shenyang, People's Republic of China
| | - Shuang Zhao
- Department of Respiratory and Intensive Care Unit, Shengjing Hospital of China Medical University, Shenyang, Postal Code 110004, People's Republic of China
| | - Xue-Fei Sun
- Department of Pharmaceutical Toxicology, School of Pharmaceutical Sciences, China Medical University, Shenyang, People's Republic of China
| | - Ming Lei
- Department of Pharmaceutical Toxicology, School of Pharmaceutical Sciences, China Medical University, Shenyang, People's Republic of China
| | - Guang-Yu Jiao
- Department of Respiratory and Intensive Care Unit, Shengjing Hospital of China Medical University, Shenyang, Postal Code 110004, People's Republic of China
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28
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Morgan CP, Krey JF, Grati M, Zhao B, Fallen S, Kannan-Sundhari A, Liu XZ, Choi D, Müller U, Barr-Gillespie PG. PDZD7-MYO7A complex identified in enriched stereocilia membranes. eLife 2016; 5:e18312. [PMID: 27525485 PMCID: PMC5005036 DOI: 10.7554/elife.18312] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 08/14/2016] [Indexed: 12/15/2022] Open
Abstract
While more than 70 genes have been linked to deafness, most of which are expressed in mechanosensory hair cells of the inner ear, a challenge has been to link these genes into molecular pathways. One example is Myo7a (myosin VIIA), in which deafness mutations affect the development and function of the mechanically sensitive stereocilia of hair cells. We describe here a procedure for the isolation of low-abundance protein complexes from stereocilia membrane fractions. Using this procedure, combined with identification and quantitation of proteins with mass spectrometry, we demonstrate that MYO7A forms a complex with PDZD7, a paralog of USH1C and DFNB31. MYO7A and PDZD7 interact in tissue-culture cells, and co-localize to the ankle-link region of stereocilia in wild-type but not Myo7a mutant mice. Our data thus describe a new paradigm for the interrogation of low-abundance protein complexes in hair cell stereocilia and establish an unanticipated link between MYO7A and PDZD7.
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Affiliation(s)
- Clive P Morgan
- Oregon Hearing Research Center and Vollum Institute, Oregon Health and Science University, Portland, United States
| | - Jocelyn F Krey
- Oregon Hearing Research Center and Vollum Institute, Oregon Health and Science University, Portland, United States
| | - M'hamed Grati
- Department of Otolaryngology, Miller School of Medicine, University of Miami, Miami, United States
| | - Bo Zhao
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, United States
| | - Shannon Fallen
- Oregon Hearing Research Center and Vollum Institute, Oregon Health and Science University, Portland, United States
| | | | - Xue Zhong Liu
- Department of Otolaryngology, Miller School of Medicine, University of Miami, Miami, United States
| | - Dongseok Choi
- OHSU-PSU School of Public Health, Oregon Health and Science University, Portland, United States
- Graduate School of Dentistry, Kyung Hee University, Seoul, Korea
| | - Ulrich Müller
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, United States
| | - Peter G Barr-Gillespie
- Oregon Hearing Research Center and Vollum Institute, Oregon Health and Science University, Portland, United States
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29
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Complex I function in mitochondrial supercomplexes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:991-1000. [DOI: 10.1016/j.bbabio.2016.01.013] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 01/20/2016] [Accepted: 01/22/2016] [Indexed: 02/02/2023]
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30
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Houser JR, Busch DJ, Bell DR, Li B, Ren P, Stachowiak JC. The impact of physiological crowding on the diffusivity of membrane bound proteins. SOFT MATTER 2016; 12:2127-34. [PMID: 26751985 PMCID: PMC4749440 DOI: 10.1039/c5sm02572a] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Diffusion of transmembrane and peripheral membrane-bound proteins within the crowded cellular membrane environment is essential to diverse biological processes including cellular signaling, endocytosis, and motility. Nonetheless we presently lack a detailed understanding of the influence of physiological levels of crowding on membrane protein diffusion. Utilizing quantitative in vitro measurements, here we demonstrate that the diffusivities of membrane bound proteins follow a single linearly decreasing trend with increasing membrane coverage by proteins. This trend holds for homogenous protein populations across a range of protein sizes and for heterogeneous mixtures of proteins of different sizes, such that protein diffusivity is controlled by the total coverage of the surrounding membrane. These results demonstrate that steric exclusion within the crowded membrane environment can fundamentally limit the diffusive rate of proteins, regardless of their size. In cells this "speed limit" could be modulated by changes in local membrane coverage, providing a mechanism for tuning the rate of molecular interaction and assembly.
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Affiliation(s)
- Justin R Houser
- Department of Biomedical Engineering, The University of Texas at Austin, TX, Austin, USA.
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31
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Markevich NI, Hoek JB. Computational modeling analysis of mitochondrial superoxide production under varying substrate conditions and upon inhibition of different segments of the electron transport chain. BIOCHIMICA ET BIOPHYSICA ACTA 2015; 1847:656-79. [PMID: 25868872 PMCID: PMC4426091 DOI: 10.1016/j.bbabio.2015.04.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Revised: 03/24/2015] [Accepted: 04/06/2015] [Indexed: 12/13/2022]
Abstract
A computational mechanistic model of superoxide (O2•-) formation in the mitochondrial electron transport chain (ETC) was developed to facilitate the quantitative analysis of factors controlling mitochondrial O2•- production and assist in the interpretation of experimental studies. The model takes into account all individual electron transfer reactions in Complexes I and III. The model accounts for multiple, often seemingly contradictory observations on the effects of ΔΨ and ΔpH, and for the effects of multiple substrate and inhibitor conditions, including differential effects of Complex III inhibitors antimycin A, myxothiazol and stigmatellin. Simulation results confirm that, in addition to O2•- formation in Complex III and at the flavin site of Complex I, the quinone binding site of Complex I is an additional superoxide generating site that accounts for experimental observations on O2•- production during reverse electron transfer. However, our simulation results predict that, when cytochrome c oxidase is inhibited during oxidation of succinate, ROS production at this site is eliminated and almost all superoxide in Complex I is generated by reduced FMN, even when the redox pressure for reverse electron transfer from succinate is strong. In addition, the model indicates that conflicting literature data on the kinetics of electron transfer in Complex III involving the iron-sulfur protein-cytochrome bL complex can be resolved in favor of a dissociation of the protein only after electron transfer to cytochrome bH. The model predictions can be helpful in understanding factors driving mitochondrial superoxide formation in intact cells and tissues.
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Affiliation(s)
- Nikolai I Markevich
- MitoCare Center for Mitochondrial Research, Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA; Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region 14290, Russia.
| | - Jan B Hoek
- MitoCare Center for Mitochondrial Research, Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
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32
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Schmitt S, Schulz S, Schropp EM, Eberhagen C, Simmons A, Beisker W, Aichler M, Zischka H. Why to compare absolute numbers of mitochondria. Mitochondrion 2014; 19 Pt A:113-23. [PMID: 24969531 DOI: 10.1016/j.mito.2014.06.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 06/05/2014] [Accepted: 06/17/2014] [Indexed: 01/01/2023]
Abstract
Prompted by pronounced structural differences between rat liver and rat hepatocellular carcinoma mitochondria, we suspected these mitochondrial populations to differ massively in their molecular composition. Aiming to reveal these mitochondrial differences, we came across the issue on how to normalize such comparisons and decided to focus on the absolute number of mitochondria. To this end, fluorescently stained mitochondria were quantified by flow cytometry. For rat liver mitochondria, this approach resulted in mitochondrial protein contents comparable to earlier reports using alternative methods. We determined similar protein contents for rat liver, heart and kidney mitochondria. In contrast, however, lower protein contents were determined for rat brain mitochondria and for mitochondria from the rat hepatocellular carcinoma cell line McA 7777. This result challenges mitochondrial comparisons that rely on equal protein amounts as a typical normalization method. Exemplarily, we therefore compared the activity and susceptibility toward inhibition of complex II of rat liver and hepatocellular carcinoma mitochondria and obtained significant discrepancies by either normalizing to protein amount or to absolute mitochondrial number. Importantly, the latter normalization, in contrast to the former, demonstrated a lower complex II activity and higher susceptibility toward inhibition in hepatocellular carcinoma mitochondria compared to liver mitochondria. These findings demonstrate that solely normalizing to protein amount may obscure essential molecular differences between mitochondrial populations.
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Affiliation(s)
- Sabine Schmitt
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Center Munich, German Research Center for Environmental Health, D-85764 Neuherberg, Germany
| | - Sabine Schulz
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Center Munich, German Research Center for Environmental Health, D-85764 Neuherberg, Germany
| | - Eva-Maria Schropp
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Center Munich, German Research Center for Environmental Health, D-85764 Neuherberg, Germany
| | - Carola Eberhagen
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Center Munich, German Research Center for Environmental Health, D-85764 Neuherberg, Germany
| | - Alisha Simmons
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Center Munich, German Research Center for Environmental Health, D-85764 Neuherberg, Germany
| | - Wolfgang Beisker
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Center Munich, German Research Center for Environmental Health, D-85764 Neuherberg, Germany
| | - Michaela Aichler
- Research Unit Analytical Pathology-Institute of Pathology, Helmholtz Center Munich, German Research Center for Environmental Health, D-85764 Neuherberg, Germany
| | - Hans Zischka
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Center Munich, German Research Center for Environmental Health, D-85764 Neuherberg, Germany.
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33
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Functional role of mitochondrial respiratory supercomplexes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:427-43. [DOI: 10.1016/j.bbabio.2013.11.002] [Citation(s) in RCA: 224] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 10/30/2013] [Accepted: 11/02/2013] [Indexed: 12/30/2022]
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34
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Analysis of the kinetics and bistability of ubiquinol:cytochrome c oxidoreductase. Biophys J 2014; 105:343-55. [PMID: 23870256 DOI: 10.1016/j.bpj.2013.05.033] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 03/28/2013] [Accepted: 05/13/2013] [Indexed: 11/21/2022] Open
Abstract
Ubiquinol:cytochrome c oxidoreductase, bc1 complex, is the enzyme in the respiratory chain of mitochondria responsible for the transfer reducing potential from ubiquinol to cytochrome c coupled to the movement of charge against the electrostatic potential across the mitochondrial inner membrane. The complex is also implicated in the generation of reactive oxygen species under certain conditions and is thus a contributor to cellular oxidative stress. Here, a biophysically detailed, thermodynamically consistent model of the bc1 complex for mammalian mitochondria is developed. The model incorporates the major redox centers near the Qo- and Qi-site of the enzyme, includes the pH-dependent redox reactions, accounts for the effect of the proton-motive force of the reaction rate, and simulates superoxide production at the Qo-site. The model consists of six distinct states characterized by the mobile electron distribution in the enzyme. Within each state, substates that correspond to various electron localizations exist in a rapid equilibrium distribution. The steady-state equation for the six-state system is parameterized using five independent data sets and validated in comparison to additional experimental data. Model analysis suggests that the pH-dependence on turnover is primarily due to the pKa values of cytochrome bH and Rieske iron sulfur protein. A previously proposed kinetic scheme at the Qi-site where ubiquinone binds to only the reduced enzyme and ubiquinol binds to only the oxidized enzyme is shown to be thermodynamically infeasible. Moreover, the model is able to reproduce the bistability phenomenon where at a given overall flux through the enzyme, different rates of superoxide production are attained when the enzyme is differentially reduced.
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35
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Kane DA, Pavlov EV. Calculation of ion currents across the inner membrane of functionally intact mitochondria. Channels (Austin) 2013; 7:426-31. [PMID: 24037064 DOI: 10.4161/chan.26290] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Mitochondrial ion transport systems play a central role in cell physiology. Rates of Ca (2+) and K(+) transport across the inner mitochondrial membrane have been derived from the measurement of ion accumulation over time within functional isolated mitochondria or mitochondria of cultured cells. Alternatively, the electrical currents generated by ionic flux have been directly measured in purified and swollen mitochondrial samples (mitoplasts) or reconstituted channels, and typically range from 1 pA to several 100s pA. However, the direct electrophysiological approach necessarily requires extensive processing of the mitochondria prior to measurement, which can only be performed on isolated mitoplasts. To compare rates of mitochondrial ion transport measured in electrophysiological experiments to those measured in intact mitochondria and cells, we converted published rates of mitochondrial ion uptake into units of ionic current. We estimate that for monovalent ions, uptake by intact mitochondria at the rate of 1 nmol ∙ mg(-1) protein ∙ min(-1) is equivalent to 0.2 fA of current per whole single mitochondrion (0.4 fA for divalent ions). In intact mitochondria, estimated rates of electrogenic cation uptake are limited to 1-100 fA of integral current per single mitochondrion. These estimates are orders of magnitude lower than the currents through mitochondrial channels directly measured via patch-clamp or artificial lipid bilayer approaches.
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Affiliation(s)
- Daniel A Kane
- Department of Human Kinetics; St. Francis Xavier University; Antigonish, Nova Scotia, Canada
| | - Evgeny V Pavlov
- Department of Physiology and Biophysics; Dalhousie University; Halifax, Nova Scotia, Canada
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36
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Role of polyhydroxybutyrate in mitochondrial calcium uptake. Cell Calcium 2013; 54:86-94. [PMID: 23702223 DOI: 10.1016/j.ceca.2013.04.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 04/11/2013] [Accepted: 04/23/2013] [Indexed: 01/12/2023]
Abstract
Polyhydroxybutyrate (PHB) is a biological polymer which belongs to the class of polyesters and is ubiquitously present in all living organisms. Mammalian mitochondrial membranes contain PHB consisting of up to 120 hydroxybutyrate residues. Roles played by PHB in mammalian mitochondria remain obscure. It was previously demonstrated that PHB of the size similar to one found in mitochondria mediates calcium transport in lipid bilayer membranes. We hypothesized that the presence of PHB in mitochondrial membrane might play a significant role in mitochondrial calcium transport. To test this, we investigated how the induction of PHB hydrolysis affects mitochondrial calcium transport. Mitochondrial PHB was altered enzymatically by targeted expression of bacterial PHB hydrolyzing enzyme (PhaZ7) in mitochondria of mammalian cultured cells. The expression of PhaZ7 induced changes in mitochondrial metabolism resulting in decreased mitochondrial membrane potential in HepG2 but not in U87 and HeLa cells. Furthermore, it significantly inhibited mitochondrial calcium uptake in intact HepG2, U87 and HeLa cells stimulated by the ATP or by the application of increased concentrations of calcium to the digitonin permeabilized cells. Calcium uptake in PhaZ7 expressing cells was restored by mimicking calcium uniporter properties with natural electrogenic calcium ionophore - ferutinin. We propose that PHB is a previously unrecognized important component of the mitochondrial calcium uptake system.
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37
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Schulz S, Schmitt S, Wimmer R, Aichler M, Eisenhofer S, Lichtmannegger J, Eberhagen C, Artmann R, Tookos F, Walch A, Krappmann D, Brenner C, Rust C, Zischka H. Progressive stages of mitochondrial destruction caused by cell toxic bile salts. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2121-33. [PMID: 23685124 DOI: 10.1016/j.bbamem.2013.05.007] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 04/26/2013] [Accepted: 05/07/2013] [Indexed: 11/19/2022]
Abstract
The cell-toxic bile salt glycochenodeoxycholic acid (GCDCA) and taurochenodeoxycholic acid (TCDCA) are responsible for hepatocyte demise in cholestatic liver diseases, while tauroursodeoxycholic acid (TUDCA) is regarded hepatoprotective. We demonstrate the direct mitochondrio-toxicity of bile salts which deplete the mitochondrial membrane potential and induce the mitochondrial permeability transition (MPT). The bile salt mediated mechanistic mode of destruction significantly differs from that of calcium, the prototype MPT inducer. Cell-toxic bile salts initially bind to the mitochondrial outer membrane. Subsequently, the structure of the inner boundary membrane disintegrates. And it is only thereafter that the MPT is induced. This progressive destruction occurs in a dose- and time-dependent way. We demonstrate that GCDCA and TCDCA, but not TUDCA, preferentially permeabilize liposomes containing the mitochondrial membrane protein ANT, a process resembling the MPT induction in whole mitochondria. This suggests that ANT is one decisive target for toxic bile salts. To our knowledge this is the first report unraveling the consecutive steps leading to mitochondrial destruction by cell-toxic bile salts.
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Affiliation(s)
- Sabine Schulz
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Center Munich, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, D-85764 Neuherberg, Germany
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38
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Bazil JN, Blomeyer CA, Pradhan RK, Camara AKS, Dash RK. Modeling the calcium sequestration system in isolated guinea pig cardiac mitochondria. J Bioenerg Biomembr 2012. [PMID: 23180139 DOI: 10.1007/s10863-012-9488-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Under high Ca(2+) load conditions, Ca(2+) concentrations in the extra-mitochondrial and mitochondrial compartments do not display reciprocal dynamics. This is due to a paradoxical increase in the mitochondrial Ca(2+) buffering power as the Ca(2+) load increases. Here we develop and characterize a mechanism of the mitochondrial Ca(2+) sequestration system using an experimental data set from isolated guinea pig cardiac mitochondria. The proposed mechanism elucidates this phenomenon and others in a mathematical framework and is integrated into a previously corroborated model of oxidative phosphorylation including the Na(+)/Ca(2+) cycle. The integrated model reproduces the Ca(2+) dynamics observed in both compartments of the isolated mitochondria respiring on pyruvate after a bolus of CaCl2 followed by ruthenium red and a bolus of NaCl. The model reveals why changes in mitochondrial Ca(2+) concentration of Ca(2+) loaded mitochondria appear significantly mitigated relative to the corresponding extra-mitochondrial Ca(2+) concentration changes after Ca(2+) efflux is initiated. The integrated model was corroborated by simulating the set-point phenomenon. The computational results support the conclusion that the Ca(2+) sequestration system is composed of at least two classes of Ca(2+) buffers. The first class represents prototypical Ca(2+) buffering, and the second class encompasses the complex binding events associated with the formation of amorphous calcium phosphate. With the Ca(2+) sequestration system in mitochondria more precisely defined, computer simulations can aid in the development of innovative therapeutics aimed at addressing the myriad of complications that arise due to mitochondrial Ca(2+) overload.
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Affiliation(s)
- Jason N Bazil
- Biotechnology and Bioengineering Center and Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA
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39
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Seidlmayer LK, Gomez-Garcia MR, Blatter LA, Pavlov E, Dedkova EN. Inorganic polyphosphate is a potent activator of the mitochondrial permeability transition pore in cardiac myocytes. ACTA ACUST UNITED AC 2012; 139:321-31. [PMID: 22547663 PMCID: PMC3343371 DOI: 10.1085/jgp.201210788] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Mitochondrial dysfunction caused by excessive Ca2+ accumulation is a major contributor to cardiac cell and tissue damage during myocardial infarction and ischemia–reperfusion injury (IRI). At the molecular level, mitochondrial dysfunction is induced by Ca2+-dependent opening of the mitochondrial permeability transition pore (mPTP) in the inner mitochondrial membrane, which leads to the dissipation of mitochondrial membrane potential (ΔΨm), disruption of adenosine triphosphate production, and ultimately cell death. Although the role of Ca2+ for induction of mPTP opening is established, the exact molecular mechanism of this process is not understood. The aim of the present study was to test the hypothesis that the adverse effect of mitochondrial Ca2+ accumulation is mediated by its interaction with inorganic polyphosphate (polyP), a polymer of orthophosphates linked by phosphoanhydride bonds. We found that cardiac mitochondria contained significant amounts (280 ± 60 pmol/mg of protein) of short-chain polyP with an average length of 25 orthophosphates. To test the role of polyP for mPTP activity, we investigated kinetics of Ca2+ uptake and release, ΔΨm and Ca2+-induced mPTP opening in polyP-depleted mitochondria. polyP depletion was achieved by mitochondria-targeted expression of a polyP-hydrolyzing enzyme. Depletion of polyP in mitochondria of rabbit ventricular myocytes led to significant inhibition of mPTP opening without affecting mitochondrial Ca2+ concentration by itself. This effect was observed when mitochondrial Ca2+ uptake was stimulated by increasing cytosolic [Ca2+] in permeabilized myocytes mimicking mitochondrial Ca2+ overload observed during IRI. Our findings suggest that inorganic polyP is a previously unrecognized major activator of mPTP. We propose that the adverse effect of polyphosphate might be caused by its ability to form stable complexes with Ca2+ and directly contribute to inner mitochondrial membrane permeabilization.
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Affiliation(s)
- Lea K Seidlmayer
- Department of Molecular Physiology and Biophysics, Rush University Medical Center, Chicago, IL 60612, USA
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40
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Effect of liposomes on energy-dependent uptake of the antioxidant SkQR1 by isolated mitochondria. J Bioenerg Biomembr 2012; 44:453-60. [DOI: 10.1007/s10863-012-9449-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Accepted: 05/21/2012] [Indexed: 12/24/2022]
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41
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Lenaz G, Genova ML. Supramolecular Organisation of the Mitochondrial Respiratory Chain: A New Challenge for the Mechanism and Control of Oxidative Phosphorylation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 748:107-44. [DOI: 10.1007/978-1-4614-3573-0_5] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Bajpeyi S, Pasarica M, Moro C, Conley K, Jubrias S, Sereda O, Burk DH, Zhang Z, Gupta A, Kjems L, Smith SR. Skeletal muscle mitochondrial capacity and insulin resistance in type 2 diabetes. J Clin Endocrinol Metab 2011; 96:1160-8. [PMID: 21307136 PMCID: PMC3070252 DOI: 10.1210/jc.2010-1621] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
OBJECTIVE The objective of this study was to determine the role of maximum mitochondrial capacity on the variation in insulin sensitivity within a population of patients with type 2 diabetes mellitus (T2DM). RESEARCH DESIGN AND METHODS Fifty-eight participants enrolled in a cross-sectional design: eight active controls [maximum aerobic capacity (VO(2max)) > 40 ml/kg · min], 17 healthy sedentary controls without a family history (FH-) and seven with a family history (FH+) of diabetes, four obese participants, and 21 patients with T2DM. Mitochondrial capacity was measured noninvasively using (31)P magnetic resonance spectroscopy of the vastus lateralis. Maximal ATP synthetic rate (ATP(max)) was determined from the rate of phosphocreatine (PCr) recovery after short-term isometric exercise. RESULTS ATP(max) was lower (P < 0.001) in T2DM and higher (P < 0.001) in active as compared with healthy sedentary FH- (active, 1.01 ± 0.2; FH-, 0.7 ± 0.2; FH+, 0.6 ± 0.1; obese, 0.6 ± 0.1; T2DM, 0.5 ± 0.2 mm ATP/sec; ANOVA P < 0.0001). Insulin sensitivity, measured by euglycemic-hyperinsulinemic (80 mIU/m(2) · min) clamp was also reduced in T2DM (P < 0.001) (active, 12.0 ± 3.2; FH-, 7.8 ± 2.2; FH+, 6.8 ± 3.5; obese, 3.1 ± 1.0; T2DM, 3.4 ± 1.6; mg/kg estimated metabolic body size · min; ANOVA P < 0.0001). Unexpectedly, there was a broad range of ATP(max) within the T2DM population where 52% of subjects with T2DM had ATP(max) values that were within the range observed in healthy sedentary controls. In addition, 24% of the T2DM subjects overlapped with the active control group (range, 0.65-1.27 mm ATP/sec). In contrast to the positive correlation between ATP(max) and M-value in the whole population (r(2) = 0.35; P < 0.0001), there was no correlation between ATP(max) and M-value in the patients with T2DM (r(2) = 0.004; P = 0.79). CONCLUSIONS Mitochondrial capacity is not associated with insulin action in T2DM.
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Affiliation(s)
- Sudip Bajpeyi
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge,Louisiana 70808, USA
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Schindeldecker M, Stark M, Behl C, Moosmann B. Differential cysteine depletion in respiratory chain complexes enables the distinction of longevity from aerobicity. Mech Ageing Dev 2011; 132:171-9. [PMID: 21453719 DOI: 10.1016/j.mad.2011.03.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2010] [Revised: 02/19/2011] [Accepted: 03/05/2011] [Indexed: 11/27/2022]
Abstract
Mitochondrially encoded proteins in long-lived animals exhibit a characteristic anomaly on the amino acid usage level: they abstain from the use of cysteine in a lifespan-dependent fashion. Here, we have further investigated this phenomenon by analyzing respiratory chain complex subunits individually. We find that complex I cysteine depletion is the almost exclusive carrier of the cysteine-lifespan correlation, whereas complex IV cysteine depletion is uniform in all aerobic animals, unrelated to longevity, but even more pronounced than complex I cysteine depletion in the longest-lived species. In nuclear encoded subunits of the respiratory chain, we find lifespan-independent cysteine depletion ranging from moderate in complex I to severe in complex V. However, a separate analysis of the transmembrane domains of these proteins unmasks an intramembrane pattern of cysteine usage that significantly correlates with longevity. Hence, cysteine usage in the respiratory chain seems to be governed by two independent molecular mechanisms acting on the protein level: a global trend of cysteine avoidance in all proteins, and a specific effect on transmembrane domain cysteines that reflects longevity. To account for these characteristic patterns, a thiyl radical-based molecular mechanism of intramembrane hydrophobic cross-linking is discussed.
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Affiliation(s)
- Mario Schindeldecker
- Evolutionary Pathobiochemistry Group, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, Mainz, Germany
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45
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Giulivi C, Ross-Inta C, Omanska-Klusek A, Napoli E, Sakaguchi D, Barrientos G, Allen PD, Pessah IN. Basal bioenergetic abnormalities in skeletal muscle from ryanodine receptor malignant hyperthermia-susceptible R163C knock-in mice. J Biol Chem 2011; 286:99-113. [PMID: 20978128 PMCID: PMC3013050 DOI: 10.1074/jbc.m110.153247] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Revised: 10/13/2010] [Indexed: 12/25/2022] Open
Abstract
Malignant hyperthermia (MH) and central core disease in humans have been associated with mutations in the skeletal ryanodine receptor (RyR1). Heterozygous mice expressing the human MH/central core disease RyR1 R163C mutation exhibit MH when exposed to halothane or heat stress. Considering that many MH symptoms resemble those that could ensue from a mitochondrial dysfunction (e.g. metabolic acidosis and hyperthermia) and that MH-susceptible mice or humans have a higher than normal cytoplasmic Ca(2+) concentration at rest, we evaluated the role of mitochondria in skeletal muscle from R163C compared with wild type mice under basal (untriggered) conditions. R163C skeletal muscle exhibited a significant increase in matrix Ca(2+), increased reactive oxygen species production, lower expression of mitochondrial proteins, and higher mtDNA copy number. These changes, in conjunction with lower myoglobin and glycogen contents, Myh4 and GAPDH transcript levels, GAPDH activity, and lower glucose utilization suggested a switch to a compromised bioenergetic state characterized by both low oxidative phosphorylation and glycolysis. The shift in bioenergetic state was accompanied by a dysregulation of Ca(2+)-responsive signaling pathways regulated by calcineurin and ERK1/2. Chronically elevated resting Ca(2+) in R163C skeletal muscle elicited the maintenance of a fast-twitch fiber program and the development of insulin resistance-like phenotype as part of a metabolic adaptation to the R163C RyR1 mutation.
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Affiliation(s)
- Cecilia Giulivi
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, California 95616, USA.
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Böhme R, Mkandawire M, Krause-Buchholz U, Rösch P, Rödel G, Popp J, Deckert V. Characterizing cytochrome c states – TERS studies of whole mitochondria. Chem Commun (Camb) 2011; 47:11453-5. [DOI: 10.1039/c1cc15246g] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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47
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Wojtovich AP, Nehrke KW, Brookes PS. The mitochondrial complex II and ATP-sensitive potassium channel interaction: quantitation of the channel in heart mitochondria. Acta Biochim Pol 2010; 57:431-434. [PMID: 21103454 PMCID: PMC4030432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Revised: 10/31/2010] [Accepted: 11/15/2010] [Indexed: 05/30/2023]
Abstract
The mitochondrial ATP-sensitive potassium channel (mK(ATP)) is important in cardioprotection, although the channel remains molecularly undefined. Several studies have demonstrated that mitochondrial complex II inhibitors activate the mK(ATP), suggesting a potential role for complex II in channel composition or regulation. However, these inhibitors activate mK(ATP) at concentrations which do not affect bulk complex II activity. Using the potent complex II inhibitor Atpenin A5, this relationship was investigated using tight-binding inhibitor theory, to demonstrate that only 0.4 % of total complex II molecules are necessary to activate the mK(ATP). These results estimate the mK(ATP) content at 15 channels per mitochondrion.
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Affiliation(s)
- Andrew P. Wojtovich
- Department of Anesthesiology, University of Rochester Medical Center, Rochester, NY, USA
| | - Keith W. Nehrke
- Department of Medicine, University of Rochester Medical Center, Rochester, NY, USA
| | - Paul S. Brookes
- Department of Anesthesiology, University of Rochester Medical Center, Rochester, NY, USA
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Moosmann B. Respiratory chain cysteine and methionine usage indicate a causal role for thiyl radicals in aging. Exp Gerontol 2010; 46:164-9. [PMID: 20850516 DOI: 10.1016/j.exger.2010.08.034] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2010] [Revised: 08/29/2010] [Accepted: 08/31/2010] [Indexed: 12/19/2022]
Abstract
The identification of longevity-related structural adaptations in biological macromolecules may yield relevant insights into the molecular mechanisms of aging. In screening fully sequenced animal proteomes for signals associated with longevity, it was found that cysteine depletion in respiratory chain complexes was the by far strongest predictor on the amino acid usage level to co-vary with lifespan. This association was though restricted to aerobic animals, whereas anaerobic animals showed variable cysteine accumulation. By contrast, methionine accumulation, a prominent feature of mitochondrially encoded proteins affording competitive antioxidant protection, was not predictive of longevity, but rather paralleled aerobic metabolic capacity. Hence, the easily oxidized sulfur-containing amino acids cysteine (a thiol) and methionine (a thioether) show doubly diametrical behaviour in two central paradigms of respiratory oxidative stress. From this comparison, it is concluded that only the one-electron oxidation of thiols to thiyl radicals contributes to aging, whereas other forms of sulfur oxidation, especially even-electron oxidation of both thiols and thioethers, are less critically involved, presumably as their consequences may be much more easily repaired. Thiyl radicals may yet act as chain-transfer agents to entail an irreversible intramembrane cross-linking ("plastination") of some of the a priori most hydrophobic and insoluble proteins known, the respiratory chain complexes.
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Affiliation(s)
- Bernd Moosmann
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany.
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49
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Lenaz G, Baracca A, Barbero G, Bergamini C, Dalmonte ME, Del Sole M, Faccioli M, Falasca A, Fato R, Genova ML, Sgarbi G, Solaini G. Mitochondrial respiratory chain super-complex I–III in physiology and pathology. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:633-40. [DOI: 10.1016/j.bbabio.2010.01.025] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2009] [Revised: 01/20/2010] [Accepted: 01/20/2010] [Indexed: 11/27/2022]
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50
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Luzikov VN. Principles of control over formation of structures responsible for respiratory functions of mitochondria. BIOCHEMISTRY (MOSCOW) 2010; 74:1443-56. [PMID: 20210702 DOI: 10.1134/s0006297909130021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Topogenesis of mitochondrial proteins includes their synthesis in cytosol and mitochondria, their translocation across the outer and inner membranes, sorting to various mitochondrial compartments, and assembly of different protein complexes. These complexes are involved in transport functions, electron transfer through the respiratory chain, generation of transmembrane electrochemical potential, oxidative phosphorylation of ADP into ATP, etc. To perform these functions, a special stringent control is required over formation of submitochondrial structures and the mitochondrion as a whole. Such control is expected to rigorously eliminate not only misfolded proteins but also incorrectly incorporated subunits and is realized in mitochondria by means of numerous proteases with different functions and localizations. In the case of more complicated protein formations, e.g. supercomplexes, the protein quality is assessed by their ability to realize the integral function of the respiratory chain and, thus, ensure the stability of the whole system. Considering supercomplexes of the mitochondrial respiratory chain, the present review clearly demonstrates that this control is realized by means of various (mainly vacuolar) proteases with different functions and localizations. The contemporary experimental data also confirm the author's original idea that the general mechanism of assembly of subcellular structures is based on the "selection by performance criterion" and "stabilization by functioning".
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Affiliation(s)
- V N Luzikov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.
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