1
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Čunátová K, Fernández-Vizarra E. Pathological variants in nuclear genes causing mitochondrial complex III deficiency: An update. J Inherit Metab Dis 2024. [PMID: 39053894 DOI: 10.1002/jimd.12751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 04/24/2024] [Accepted: 05/02/2024] [Indexed: 07/27/2024]
Abstract
Mitochondrial disorders are a group of clinically and biochemically heterogeneous genetic diseases within the group of inborn errors of metabolism. Primary mitochondrial diseases are mainly caused by defects in one or several components of the oxidative phosphorylation system (complexes I-V). Within these disorders, those associated with complex III deficiencies are the least common. However, thanks to a deeper knowledge about complex III biogenesis, improved clinical diagnosis and the implementation of next-generation sequencing techniques, the number of pathological variants identified in nuclear genes causing complex III deficiency has expanded significantly. This updated review summarizes the current knowledge concerning the genetic basis of complex III deficiency, and the main clinical features associated with these conditions.
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Affiliation(s)
- Kristýna Čunátová
- Department of Biomedical Sciences, University of Padova, Padova, Italy
- Veneto Institute of Molecular Medicine, Padova, Italy
| | - Erika Fernández-Vizarra
- Department of Biomedical Sciences, University of Padova, Padova, Italy
- Veneto Institute of Molecular Medicine, Padova, Italy
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2
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Tikhonov AN. The cytochrome b 6f complex: plastoquinol oxidation and regulation of electron transport in chloroplasts. PHOTOSYNTHESIS RESEARCH 2024; 159:203-227. [PMID: 37369875 DOI: 10.1007/s11120-023-01034-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 06/12/2023] [Indexed: 06/29/2023]
Abstract
In oxygenic photosynthetic systems, the cytochrome b6f (Cytb6f) complex (plastoquinol:plastocyanin oxidoreductase) is a heart of the hub that provides connectivity between photosystems (PS) II and I. In this review, the structure and function of the Cytb6f complex are briefly outlined, being focused on the mechanisms of a bifurcated (two-electron) oxidation of plastoquinol (PQH2). In plant chloroplasts, under a wide range of experimental conditions (pH and temperature), a diffusion of PQH2 from PSII to the Cytb6f does not limit the intersystem electron transport. The overall rate of PQH2 turnover is determined mainly by the first step of the bifurcated oxidation of PQH2 at the catalytic site Qo, i.e., the reaction of electron transfer from PQH2 to the Fe2S2 cluster of the high-potential Rieske iron-sulfur protein (ISP). This point has been supported by the quantum chemical analysis of PQH2 oxidation within the framework of a model system including the Fe2S2 cluster of the ISP and surrounding amino acids, the low-potential heme b6L, Glu78 and 2,3,5-trimethylbenzoquinol (the tail-less analog of PQH2). Other structure-function relationships and mechanisms of electron transport regulation of oxygenic photosynthesis associated with the Cytb6f complex are briefly outlined: pH-dependent control of the intersystem electron transport and the regulatory balance between the operation of linear and cyclic electron transfer chains.
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Affiliation(s)
- Alexander N Tikhonov
- Department of Biophysics, Faculty of Physics, M.V. Lomonosov Moscow State University, Moscow, Russian Federation, 119991.
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3
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Havens J, Su T, Wang Q, Yu CA, Yu L, Durham B, Millett F. Photoinduced electron transfer in cytochrome bc 1: Dynamics of rotation of the Iron-sulfur protein during bifurcated electron transfer from ubiquinol to cytochrome c 1 and cytochrome b L. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148957. [PMID: 36709837 DOI: 10.1016/j.bbabio.2023.148957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Revised: 01/12/2023] [Accepted: 01/20/2023] [Indexed: 01/27/2023]
Abstract
The electron transfer reactions within wild-type Rhodobacter sphaeroides cytochrome bc1 (cyt bc1) were studied using a binuclear ruthenium complex to rapidly photooxidize cyt c1. When cyt c1, the iron‑sulfur center Fe2S2, and cyt bH were reduced before the reaction, photooxidation of cyt c1 led to electron transfer from Fe2S2 to cyt c1 with a rate constant of ka = 80,000 s-1, followed by bifurcated reduction of both Fe2S2 and cyt bL by QH2 in the Qo site with a rate constant of k2 = 3000 s-1. The resulting Q then traveled from the Qo site to the Qi site and oxidized one equivalent each of cyt bL and cyt bH with a rate constant of k3 = 340 s-1. The rate constant ka was decreased in a nonlinear fashion by a factor of 53 as the viscosity was increased to 13.7. A mechanism that is consistent with the effect of viscosity involves rotational diffusion of the iron‑sulfur protein from the b state with reduced Fe2S2 close to cyt bL to one or more intermediate states, followed by rotation to the final c1 state with Fe2S2 close to cyt c1, and rapid electron transfer to cyt c1.
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Affiliation(s)
- Jeffrey Havens
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, United States of America; Vaccines and Therapeutics Division, Chemical and Biological Technologies, Defense Threat Reduction Agency, Fort Belvoir, VA 22060, United States of America
| | - Ting Su
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, United States of America; ABclonal Technology Woburn, MA 01801, United States of America
| | - Qiyu Wang
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, United States of America; Vesigen Therapeutics Cambridge, MA 02139, United States of America
| | - Chang-An Yu
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, United States of America
| | - Linda Yu
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, United States of America
| | - Bill Durham
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, United States of America
| | - Francis Millett
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, United States of America.
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4
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Kinetic Mathematical Modeling of Oxidative Phosphorylation in Cardiomyocyte Mitochondria. Cells 2022; 11:cells11244020. [PMID: 36552784 PMCID: PMC9777548 DOI: 10.3390/cells11244020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 12/05/2022] [Accepted: 12/08/2022] [Indexed: 12/15/2022] Open
Abstract
Oxidative phosphorylation (OXPHOS) is an oxygen-dependent process that consumes catabolized nutrients to produce adenosine triphosphate (ATP) to drive energy-dependent biological processes such as excitation-contraction coupling in cardiomyocytes. In addition to in vivo and in vitro experiments, in silico models are valuable for investigating the underlying mechanisms of OXPHOS and predicting its consequences in both physiological and pathological conditions. Here, we compare several prominent kinetic models of OXPHOS in cardiomyocytes. We examine how their mathematical expressions were derived, how their parameters were obtained, the conditions of their experimental counterparts, and the predictions they generated. We aim to explore the general landscape of energy production mechanisms in cardiomyocytes for future in silico models.
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5
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Szwalec M, Bujnowicz Ł, Sarewicz M, Osyczka A. Unexpected Heme Redox Potential Values Implicate an Uphill Step in Cytochrome b6f. J Phys Chem B 2022; 126:9771-9780. [PMID: 36399615 PMCID: PMC9720722 DOI: 10.1021/acs.jpcb.2c05729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Cytochromes bc, key enzymes of respiration and photosynthesis, contain a highly conserved two-heme motif supporting cross-membrane electron transport (ET) that connects the two catalytic quinone-binding sites (Qn and Qp). Typically, this ET occurs from the low- to high-potential heme b, but in photosynthetic cytochrome b6f, the redox midpoint potentials (Ems) of these hemes remain uncertain. Our systematic redox titration analysis based on three independent and comprehensive low-temperature spectroscopies (continuous wave and pulse electron paramagnetic resonance (EPR) and optical spectroscopies) allowed for unambiguous assignment of spectral components of hemes in cytochrome b6f and revealed that Em of heme bn is unexpectedly low. Consequently, the cross-membrane ET occurs from the high- to low-potential heme introducing an uphill step in the energy landscape for the catalytic reaction. This slows down the ET through a low-potential chain, which can influence the mechanisms of reactions taking place at both Qp and Qn sites and modulate the efficiency of cyclic and linear ET in photosynthesis.
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6
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Robinson DRL, Hock DH, Muellner-Wong L, Kugapreethan R, Reljic B, Surgenor EE, Rodrigues CHM, Caruana NJ, Stroud DA. Applying Sodium Carbonate Extraction Mass Spectrometry to Investigate Defects in the Mitochondrial Respiratory Chain. Front Cell Dev Biol 2022; 10:786268. [PMID: 35300415 PMCID: PMC8921082 DOI: 10.3389/fcell.2022.786268] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 02/03/2022] [Indexed: 12/03/2022] Open
Abstract
Mitochondria are complex organelles containing 13 proteins encoded by mitochondrial DNA and over 1,000 proteins encoded on nuclear DNA. Many mitochondrial proteins are associated with the inner or outer mitochondrial membranes, either peripherally or as integral membrane proteins, while others reside in either of the two soluble mitochondrial compartments, the mitochondrial matrix and the intermembrane space. The biogenesis of the five complexes of the oxidative phosphorylation system are exemplars of this complexity. These large multi-subunit complexes are comprised of more than 80 proteins with both membrane integral and peripheral associations and require soluble, membrane integral and peripherally associated assembly factor proteins for their biogenesis. Mutations causing human mitochondrial disease can lead to defective complex assembly due to the loss or altered function of the affected protein and subsequent destabilization of its interactors. Here we couple sodium carbonate extraction with quantitative mass spectrometry (SCE-MS) to track changes in the membrane association of the mitochondrial proteome across multiple human knockout cell lines. In addition to identifying the membrane association status of over 840 human mitochondrial proteins, we show how SCE-MS can be used to understand the impacts of defective complex assembly on protein solubility, giving insights into how specific subunits and sub-complexes become destabilized.
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Affiliation(s)
- David R L Robinson
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, Australia
| | - Daniella H Hock
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, Australia
| | - Linden Muellner-Wong
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, Australia.,The Royal Children's Hospital, Murdoch Children's Research Institute, Parkville, VIC, Australia
| | - Roopasingam Kugapreethan
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, Australia
| | - Boris Reljic
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, Australia.,Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Elliot E Surgenor
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia.,The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | - Carlos H M Rodrigues
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, Australia.,Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Nikeisha J Caruana
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, Australia.,Institute for Health and Sport (IHES), Victoria University, Melbourne, VIC, Australia
| | - David A Stroud
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, Australia.,The Royal Children's Hospital, Murdoch Children's Research Institute, Parkville, VIC, Australia
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7
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Manoj KM, Gideon DA, Jaeken L. Interaction of membrane-embedded cytochrome b-complexes with quinols: Classical Q-cycle and murburn model. Cell Biochem Funct 2022; 40:118-126. [PMID: 35026863 DOI: 10.1002/cbf.3682] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 12/03/2021] [Accepted: 12/14/2021] [Indexed: 01/07/2023]
Abstract
We recently proposed a diffusible reactive (oxygen) species (DRS/DROS) based function for cytochrome b complexes (CBC) and quinones (Q)/quinols (QH2 ) in the murburn model of bioenergetics. This proposal is in direct conflict with the classical purview of Q-cycle. Via extensive analyses of the structure-function correlations of membrane-quinones/quinols and proteins, we present qualitative and quantitative arguments to infer that the classical model cannot explain the energetics, kinetics, mechanism and probabilistic considerations. Therefore, it is proposed that Q-cycle is neither necessary nor feasible at CBCs. In contrast, we substantiate that the murburn model explains: (a) crucial structural data of CBCs, (b) why quinones/quinols are utilized in bioenergetic membranes, (c) how trans-membrane potential is generated owing to effective charge separation at CBCs, (d) mobility data of O2 , DRS, Q/QH2 , and (e) utility of other reaction/membrane components. Further, the murburn model also accommodates the absence of quinones in anaerobic Archaea, wherein methanophenazines are prevalent. The work mandates that the textbooks and research agendas are refreshed to reflect the new perception. SIGNIFICANCE: The current article must be seen as a critical and detailed analysis of the role and working mechanism of quinone (Q) /quinols (QH2 ) in bioenergetic membranes. In the classical model, QH2 are perceived as highly mobile electron-transport agents that bind and donate electrons to cytochrome b complexes (CBCs), using sophisticated electronic circuitries, in order to recycle Q and pump protons. The classical perception sees radicals (such as Q*-, O2 *-, etc., also called diffusible reactive species, DRS) as wasteful or toxic (patho) physiological manifestations. It is highlighted herein that QH2 has low mobility and matrix has little protons to pump. New insights from the structural analyses of diverse CBCs and quinols, in conjunction with murburn reaction thermodynamics suggest that the electrons from substrates/quinols are effectively utilized via DRS. This perception fits into a much broader analysis of 1 and 2 electron transfers in overall redox metabolism, as recently brought out by the murburn model, wherein DRS are considered obligatory ingredients of physiology. Thus, the findings mandate a reorientation in the pertinent research field.
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Affiliation(s)
- Kelath Murali Manoj
- Biochemistry, Satyamjayatu: The Science & Ethics Foundation, Palakkad, India
| | | | - Laurent Jaeken
- Karel de Grote University College, Antwerp University Association, Campus Hoboken, Hoboken, Belgium
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8
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Capitanio G, Papa F, Papa S. The allosteric protein interactions in the proton-motive function of mammalian redox enzymes of the respiratory chain. Biochimie 2021; 189:1-12. [PMID: 34097987 DOI: 10.1016/j.biochi.2021.05.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/17/2021] [Accepted: 05/31/2021] [Indexed: 12/22/2022]
Abstract
Insight into mammalian respiratory complexes defines the role of allosteric protein interactions in their proton-motive activity. In cytochrome c oxidase (CxIV) conformational change of subunit I, caused by O2 binding to heme a32+-CuB+ and reduction, and stereochemical transitions coupled to oxidation/reduction of heme a and CuA, combined with electrostatic effects, determine the proton pumping activity. In ubiquinone-cytochrome c oxidoreductase (CxIII) conformational movement of Fe-S protein between cytochromes b and c1 is the key element of the proton-motive activity. In NADH-ubiquinone oxidoreductase (CxI) ubiquinone binding and reduction result in conformational changes of subunits in the quinone reaction structure which initiate proton pumping.
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Affiliation(s)
- Giuseppe Capitanio
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari "Aldo Moro", 70124, Bari, Italy.
| | - Francesco Papa
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari "Aldo Moro", 70124, Bari, Italy.
| | - Sergio Papa
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari "Aldo Moro", 70124, Bari, Italy; Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, 80121, Napoli, Italy.
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9
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Leung SW, Baker PL, Redding KE. Deletion of the cytochrome bc complex from Heliobacterium modesticaldum results in viable but non-phototrophic cells. PHOTOSYNTHESIS RESEARCH 2021; 148:137-152. [PMID: 34236566 DOI: 10.1007/s11120-021-00845-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Accepted: 05/04/2021] [Indexed: 06/13/2023]
Abstract
The heliobacteria, a family of anoxygenic phototrophs, possess the simplest known photosynthetic apparatus. Although they are photoheterotrophs in the light, the heliobacteria can also grow chemotrophically via pyruvate metabolism in the dark. In the heliobacteria, the cytochrome bc complex is responsible for oxidizing menaquinol and reducing cytochrome c553 in the electron flow cycle used for phototrophy. However, there is no known electron acceptor for the mobile cytochrome c553 other than the photochemical reaction center. We have, therefore, hypothesized that the cytochrome bc complex is necessary for phototrophy, but unnecessary for chemotrophic growth in the dark. We used a two-step method for CRISPR-based genome editing in Heliobacterium modesticaldum to delete the genes encoding the four major subunits of the cytochrome bc complex. Genotypic analysis verified the deletion of the petCBDA gene cluster encoding the catalytic components of the complex. Spectroscopic studies revealed that re-reduction of cytochrome c553 after flash-induced photo-oxidation was over 100 times slower in the ∆petCBDA mutant compared to the wild-type. Steady-state levels of oxidized P800 (the primary donor of the photochemical reaction center) were much higher in the ∆petCBDA mutant at every light level, consistent with a limitation in electron flow to the reaction center. The ∆petCBDA mutant was unable to grow phototrophically on acetate plus CO2 but could grow chemotrophically on pyruvate as a carbon source similar to the wild-type strain in the dark. The mutants could be complemented by reintroduction of the petCBDA gene cluster on a plasmid expressed from the clostridial eno promoter.
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Affiliation(s)
- Sabrina W Leung
- School of Molecular Sciences, Arizona State University, 1711 S Rural Rd, Box 871604, Tempe, AZ, 85287-1604, USA
| | - Patricia L Baker
- School of Molecular Sciences, Arizona State University, 1711 S Rural Rd, Box 871604, Tempe, AZ, 85287-1604, USA
| | - Kevin E Redding
- School of Molecular Sciences, Arizona State University, 1711 S Rural Rd, Box 871604, Tempe, AZ, 85287-1604, USA.
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10
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Camilo SRG, Curtolo F, Galassi VV, Arantes GM. Tunneling and Nonadiabatic Effects on a Proton-Coupled Electron Transfer Model for the Q o Site in Cytochrome bc1. J Chem Inf Model 2021; 61:1840-1849. [PMID: 33793213 DOI: 10.1021/acs.jcim.1c00008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Cytochrome bc1 is a fundamental enzyme for cellular respiration and photosynthesis. This dimeric protein complex catalyzes a proton-coupled electron transfer (PCET) from the reduced coenzyme-Q substrate (Q) to a bimetallic iron-sulfur cluster in the Qo active site. Herein, we combine molecular dynamics simulations of the complete cytochrome bc1 protein with electronic-structure calculations of truncated models and a semiclassical tunneling theory to investigate the electron-proton adiabaticity of the initial reaction catalyzed in the Qo site. After sampling possible orientations between the Q substrate and a histidine side chain that functions as hydrogen acceptor, we find that a truncated model composed by ubiquinol-methyl and imidazole-iron(III)-sulfide captures the expected changes in oxidation and spin states of the electron donor and acceptor. Diabatic electronic surfaces obtained for this model with multiconfigurational wave function calculations demonstrate that this reaction is electronic nonadiabatic, and proton tunneling is faster than mixing of electronic configurations. These results indicate the formalism that should be used to calculate vibronic couplings and kinetic parameters for the initial reaction in the Qo site of cytochrome bc1. This framework for molecular simulation may also be applied to investigate other PCET reactions in the Q-cycle or in various metalloproteins that catalyze proton translocation coupled to redox processes.
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Affiliation(s)
- Sofia R G Camilo
- Department of Biochemistry, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, 05508-900 São Paulo, SP, Brazil
| | - Felipe Curtolo
- Department of Biochemistry, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, 05508-900 São Paulo, SP, Brazil
| | - Vanesa V Galassi
- Department of Biochemistry, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, 05508-900 São Paulo, SP, Brazil
| | - Guilherme M Arantes
- Department of Biochemistry, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, 05508-900 São Paulo, SP, Brazil
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11
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Crofts AR. The modified Q-cycle: A look back at its development and forward to a functional model. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2021; 1862:148417. [PMID: 33745972 DOI: 10.1016/j.bbabio.2021.148417] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 02/28/2021] [Accepted: 03/11/2021] [Indexed: 11/25/2022]
Abstract
On looking back at a lifetime of research, it is interesting to see, in the light of current progress, how things came to be, and to speculate on how things might be. I am delighted in the context of the Mitchell prize to have that excuse to present this necessarily personal view of developments in areas of my interests. I have focused on the Q-cycle and a few examples showing wider ramifications, since that had been the main interest of the lab in the 20 years since structures became available, - a watershed event in determining our molecular perspective. I have reviewed the evidence for our model for the mechanism of the first electron transfer of the bifurcated reaction at the Qo-site, which I think is compelling. In reviewing progress in understanding the second electron transfer, I have revisited some controversies to justify important conclusions which appear, from the literature, not to have been taken seriously. I hope this does not come over as nitpicking. The conclusions are important to the final section in which I develop an internally consistent mechanism for turnovers of the complex leading to a state similar to that observed in recent rapid-mix/freeze-quench experiments, reported three years ago. The final model is necessarily speculative but is open to test.
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Affiliation(s)
- Antony R Crofts
- Department of Biochemistry, 417 Roger Adams Laboratory, 600 South Mathews Avenue, Urbana, IL 61801, United States of America
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12
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Sarewicz M, Pintscher S, Pietras R, Borek A, Bujnowicz Ł, Hanke G, Cramer WA, Finazzi G, Osyczka A. Catalytic Reactions and Energy Conservation in the Cytochrome bc1 and b6f Complexes of Energy-Transducing Membranes. Chem Rev 2021; 121:2020-2108. [PMID: 33464892 PMCID: PMC7908018 DOI: 10.1021/acs.chemrev.0c00712] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Indexed: 12/16/2022]
Abstract
This review focuses on key components of respiratory and photosynthetic energy-transduction systems: the cytochrome bc1 and b6f (Cytbc1/b6f) membranous multisubunit homodimeric complexes. These remarkable molecular machines catalyze electron transfer from membranous quinones to water-soluble electron carriers (such as cytochromes c or plastocyanin), coupling electron flow to proton translocation across the energy-transducing membrane and contributing to the generation of a transmembrane electrochemical potential gradient, which powers cellular metabolism in the majority of living organisms. Cytsbc1/b6f share many similarities but also have significant differences. While decades of research have provided extensive knowledge on these enzymes, several important aspects of their molecular mechanisms remain to be elucidated. We summarize a broad range of structural, mechanistic, and physiological aspects required for function of Cytbc1/b6f, combining textbook fundamentals with new intriguing concepts that have emerged from more recent studies. The discussion covers but is not limited to (i) mechanisms of energy-conserving bifurcation of electron pathway and energy-wasting superoxide generation at the quinol oxidation site, (ii) the mechanism by which semiquinone is stabilized at the quinone reduction site, (iii) interactions with substrates and specific inhibitors, (iv) intermonomer electron transfer and the role of a dimeric complex, and (v) higher levels of organization and regulation that involve Cytsbc1/b6f. In addressing these topics, we point out existing uncertainties and controversies, which, as suggested, will drive further research in this field.
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Affiliation(s)
- Marcin Sarewicz
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Sebastian Pintscher
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Rafał Pietras
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Arkadiusz Borek
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Łukasz Bujnowicz
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Guy Hanke
- School
of Biological and Chemical Sciences, Queen
Mary University of London, London E1 4NS, U.K.
| | - William A. Cramer
- Department
of Biological Sciences, Purdue University, West Lafayette, Indiana 47907 United States
| | - Giovanni Finazzi
- Laboratoire
de Physiologie Cellulaire et Végétale, Université Grenoble Alpes, Centre National Recherche Scientifique,
Commissariat Energie Atomique et Energies Alternatives, Institut National
Recherche l’agriculture, l’alimentation et l’environnement, 38054 Grenoble Cedex 9, France
| | - Artur Osyczka
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
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13
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Cryo-EM structures of engineered active bc 1-cbb 3 type CIII 2CIV super-complexes and electronic communication between the complexes. Nat Commun 2021; 12:929. [PMID: 33568648 PMCID: PMC7876108 DOI: 10.1038/s41467-021-21051-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 01/06/2021] [Indexed: 01/30/2023] Open
Abstract
Respiratory electron transport complexes are organized as individual entities or combined as large supercomplexes (SC). Gram-negative bacteria deploy a mitochondrial-like cytochrome (cyt) bc1 (Complex III, CIII2), and may have specific cbb3-type cyt c oxidases (Complex IV, CIV) instead of the canonical aa3-type CIV. Electron transfer between these complexes is mediated by soluble (c2) and membrane-anchored (cy) cyts. Here, we report the structure of an engineered bc1-cbb3 type SC (CIII2CIV, 5.2 Å resolution) and three conformers of native CIII2 (3.3 Å resolution). The SC is active in vivo and in vitro, contains all catalytic subunits and cofactors, and two extra transmembrane helices attributed to cyt cy and the assembly factor CcoH. The cyt cy is integral to SC, its cyt domain is mobile and it conveys electrons to CIV differently than cyt c2. The successful production of a native-like functional SC and determination of its structure illustrate the characteristics of membrane-confined and membrane-external respiratory electron transport pathways in Gram-negative bacteria.
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14
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Varricchio C, Beirne K, Aeschlimann P, Heard C, Rozanowska M, Votruba M, Brancale A. Discovery of Novel 2-Aniline-1,4-naphthoquinones as Potential New Drug Treatment for Leber's Hereditary Optic Neuropathy (LHON). J Med Chem 2020; 63:13638-13655. [PMID: 33180495 DOI: 10.1021/acs.jmedchem.0c00942] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Leber's hereditary optic neuropathy (LHON) is a rare genetic mitochondrial disease and the primary cause of chronic visual impairment for at least 1 in 10 000 individuals in the U.K. Treatment options remain limited, with only a few drug candidates and therapeutic approaches, either approved or in development. Recently, idebenone has been investigated as drug therapy in the treatment of LHON, although evidence for the efficacy of idebenone is limited in the literature. NAD(P)H:quinone oxidoreductase 1 (NQO1) and mitochondrial complex III were identified as the major enzymes involved in idebenone activity. Based on this mode of action, computer-aided techniques and structure-activity relationship (SAR) optimization studies led to the discovery of a series naphthoquinone-related small molecules, with comparable adenosine 5'-triphosphate (ATP) rescue activity to idebenone. Among these, three compounds showed activity in the nanomolar range and one, 2-((4-fluoro-3-(trifluoromethyl)phenyl)amino)-3-(methylthio)naphthalene-1,3-dione (1), demonstrated significantly higher potency ex vivo, and significantly lower cytotoxicity, than idebenone.
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Affiliation(s)
- Carmine Varricchio
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, Wales, U.K.,School of Optometry and Vision Sciences, Cardiff University, Cardiff CF10 3NB, Wales, U.K
| | - Kathy Beirne
- School of Optometry and Vision Sciences, Cardiff University, Cardiff CF10 3NB, Wales, U.K
| | - Pascale Aeschlimann
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, Wales, U.K.,School of Optometry and Vision Sciences, Cardiff University, Cardiff CF10 3NB, Wales, U.K
| | - Charles Heard
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, Wales, U.K
| | - Malgorzata Rozanowska
- School of Optometry and Vision Sciences, Cardiff University, Cardiff CF10 3NB, Wales, U.K
| | - Marcela Votruba
- School of Optometry and Vision Sciences, Cardiff University, Cardiff CF10 3NB, Wales, U.K.,Cardiff Eye Unit, University Hospital of Wales, Heath Park, Cardiff CF24 4LU, Wales, U.K
| | - Andrea Brancale
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff CF10 3NB, Wales, U.K
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15
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Fisher N, Meunier B, Biagini GA. The cytochrome bc 1 complex as an antipathogenic target. FEBS Lett 2020; 594:2935-2952. [PMID: 32573760 DOI: 10.1002/1873-3468.13868] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 05/31/2020] [Accepted: 06/10/2020] [Indexed: 12/15/2022]
Abstract
The cytochrome bc1 complex is a key component of the mitochondrial respiratory chains of many eukaryotic microorganisms that are pathogenic for plants or humans, such as fungi responsible for crop diseases and Plasmodium falciparum, which causes human malaria. Cytochrome bc1 is an enzyme that contains two (ubi)quinone/quinol-binding sites, which can be exploited for the development of fungicidal and chemotherapeutic agents. Here, we review recent progress in determination of the structure and mechanism of action of cytochrome bc1 , and the associated development of antimicrobial agents (and associated resistance mechanisms) targeting its activity.
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Affiliation(s)
- Nicholas Fisher
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Brigitte Meunier
- CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, Gif-sur-Yvette, France
| | - Giancarlo A Biagini
- Parasitology Department, Research Centre for Drugs & Diagnostics, Liverpool School of Tropical Medicine, Liverpool, UK
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16
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Mitochondrial OXPHOS Biogenesis: Co-Regulation of Protein Synthesis, Import, and Assembly Pathways. Int J Mol Sci 2020; 21:ijms21113820. [PMID: 32481479 PMCID: PMC7312649 DOI: 10.3390/ijms21113820] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 05/21/2020] [Accepted: 05/25/2020] [Indexed: 02/07/2023] Open
Abstract
The assembly of mitochondrial oxidative phosphorylation (OXPHOS) complexes is an intricate process, which—given their dual-genetic control—requires tight co-regulation of two evolutionarily distinct gene expression machineries. Moreover, fine-tuning protein synthesis to the nascent assembly of OXPHOS complexes requires regulatory mechanisms such as translational plasticity and translational activators that can coordinate mitochondrial translation with the import of nuclear-encoded mitochondrial proteins. The intricacy of OXPHOS complex biogenesis is further evidenced by the requirement of many tightly orchestrated steps and ancillary factors. Early-stage ancillary chaperones have essential roles in coordinating OXPHOS assembly, whilst late-stage assembly factors—also known as the LYRM (leucine–tyrosine–arginine motif) proteins—together with the mitochondrial acyl carrier protein (ACP)—regulate the incorporation and activation of late-incorporating OXPHOS subunits and/or co-factors. In this review, we describe recent discoveries providing insights into the mechanisms required for optimal OXPHOS biogenesis, including the coordination of mitochondrial gene expression with the availability of nuclear-encoded factors entering via mitochondrial protein import systems.
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17
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Mukherjee S, Ghosh A. Molecular mechanism of mitochondrial respiratory chain assembly and its relation to mitochondrial diseases. Mitochondrion 2020; 53:1-20. [PMID: 32304865 DOI: 10.1016/j.mito.2020.04.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 03/28/2020] [Accepted: 04/07/2020] [Indexed: 12/17/2022]
Abstract
The mitochondrial respiratory chain (MRC) is comprised of ~92 nuclear and mitochondrial DNA-encoded protein subunits that are organized into five different multi-subunit respiratory complexes. These complexes produce 90% of the ATP required for cell sustenance. Specific sets of subunits are assembled in a modular or non-modular fashion to construct the MRC complexes. The complete assembly process is gradually chaperoned by a myriad of assembly factors that must coordinate with several other prosthetic groups to reach maturity, makingthe entire processextensively complicated. Further, the individual respiratory complexes can be integrated intovarious giant super-complexes whose functional roles have yet to be explored. Mutations in the MRC subunits and in the related assembly factors often give rise to defects in the proper assembly of the respiratory chain, which then manifests as a group of disorders called mitochondrial diseases, the most common inborn errors of metabolism. This review summarizes the current understanding of the biogenesis of individual MRC complexes and super-complexes, and explores how mutations in the different subunits and assembly factors contribute to mitochondrial disease pathology.
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Affiliation(s)
- Soumyajit Mukherjee
- Department of Biochemistry, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700019, India
| | - Alok Ghosh
- Department of Biochemistry, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700019, India.
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18
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Eberhard N, Balmer V, Müller J, Müller N, Winter R, Pou S, Nilsen A, Riscoe M, Francisco S, Leitao A, Doggett JS, Hemphill A. Activities of Endochin-Like Quinolones Against in vitro Cultured Besnoitia besnoiti Tachyzoites. Front Vet Sci 2020; 7:96. [PMID: 32161765 PMCID: PMC7054222 DOI: 10.3389/fvets.2020.00096] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 02/10/2020] [Indexed: 12/14/2022] Open
Abstract
Endochin-like quinolones (ELQs) potently inhibit the proliferation of Plasmodium, Toxoplasma, Neospora, and Babesia by targeting the cytochrome b Qo and Qi sites and interfering with oxidative phosphorylation and pyrimidine biosynthesis. The activities of 14 different ELQs were assessed against B. besnoiti tachyzoites grown in human foreskin fibroblasts (HFF) by quantitative real time PCR. The values for 50% proliferation inhibition (IC50) of five ELQs were determined in a 3-days growth assay after an initial screen of 12 ELQs at 0.01, 0.1, and 1 μM. The IC50s of ELQ-121, -136, and -316 were 0.49, 2.36, and 7.97 nM, respectively. The IC50s of ELQs tested against B. besnoiti were higher than IC50s previously observed for P. falciparum and T. gondii. However, the B. besnoiti cytochrome b sequence and the predicted Qo and Qi ELQ binding sites in the Toxoplasma, Neospora, and Besnoitia cytochrome b are virtually identical, suggesting that the differences in ELQ susceptibility are not due to variations in the substrate binding sites. TEM of ELQ-treated parasites primarily demonstrated alterations within the parasite mitochondrion, profound thickening of the nuclear membrane, as well as increased vacuolization within the tachyzoite cytoplasm. Long-term treatment assays of intracellular B. besnoiti with ELQs for up to 20 days followed by the release of drug pressure caused a substantial delay in parasite growth and proliferation while ELQs were present, but parasite proliferation resumed days after ELQs were removed. Interestingly, structural alterations persisted after ELQ removal and parasite proliferation was slowed. These findings provide a basis for further in vivo studies of ELQs as therapeutic options against B. besnoiti infection.
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Affiliation(s)
- Naja Eberhard
- Vetsuisse Faculty, Institute of Parasitology, University of Bern, Bern, Switzerland
| | - Vreni Balmer
- Vetsuisse Faculty, Institute of Parasitology, University of Bern, Bern, Switzerland
| | - Joachim Müller
- Vetsuisse Faculty, Institute of Parasitology, University of Bern, Bern, Switzerland
| | - Norbert Müller
- Vetsuisse Faculty, Institute of Parasitology, University of Bern, Bern, Switzerland
| | - Rolf Winter
- VA Portland Health Care System Research and Development Service, Portland, OR, United States
| | - Soviti Pou
- VA Portland Health Care System Research and Development Service, Portland, OR, United States
| | - Aaron Nilsen
- VA Portland Health Care System Research and Development Service, Portland, OR, United States
| | - Mike Riscoe
- VA Portland Health Care System Research and Development Service, Portland, OR, United States
| | - Samuel Francisco
- Faculdade de Medicina Veterinária, CIISA—Centro de Investigação Interdisciplinar em Sanidade Animal, Universidade de Lisboa, Lisbon, Portugal
| | - Alexandre Leitao
- Faculdade de Medicina Veterinária, CIISA—Centro de Investigação Interdisciplinar em Sanidade Animal, Universidade de Lisboa, Lisbon, Portugal
| | - J. Stone Doggett
- VA Portland Health Care System Research and Development Service, Portland, OR, United States
| | - Andrew Hemphill
- Vetsuisse Faculty, Institute of Parasitology, University of Bern, Bern, Switzerland
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19
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Ishibashi T. Therapeutic Efficacy of Molecular Hydrogen: A New Mechanistic Insight. Curr Pharm Des 2020; 25:946-955. [PMID: 31057105 PMCID: PMC6806612 DOI: 10.2174/1381612825666190506123038] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 04/25/2019] [Indexed: 02/02/2023]
Abstract
Background: Molecular hydrogen (H2) is now recognized as a therapeutic gas for the treatment of numerous diseases including neurodegenerative diseases, metabolic disorders, and inflammatory diseases. Non-polar, neutral H2 is assumed to have health benefits facilitated by its passive diffusion across the human body immediately after administration and is considered a safe therapeutic inert gas that does not interfere with physiological enzymatic reactions. The effects of H2 on mammalian cells are assumed to be based on non-enzymatic reactions with Reactive Oxygen Species (ROS) exhibiting extremely high reactivity. However, many reports on therapeutic applications of H2 have the limitation to regard H2 only as a scavenger for the hydroxyl radical and peroxynitrite. Methods: Apart from this proposed principle, a new possible mechanism of H2 activation and consumption in mammalian cells is considered in this review, which is specifically focused on the mitochondrial complex I that has a close evolutionary relationship with energy-converting, membrane-bound [NiFe]-hydrogenases (MBH). Notably, the possibility that H2 may function as both electron and proton donor in the ubiquinone-binding chamber of complex I is discussed. Results: H2 is proposed to act as the rectifier of the mitochondrial electron flow in the disordered or pathological state when the accumulation of electrons leads to ROS production, specifically during the re-supply of O2 after hypoxia in the mitochondria. Conclusion: Furthermore, H2 is proposed to convert the quinone intermediates to the fully reduced ubiquinol, thereby increasing the antioxidant capacity of the quinone pool as well as preventing the generation of ROS.
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Affiliation(s)
- Toru Ishibashi
- Department of Rheumatology, Orthopaedic Surgery and Health Care, Huis Ten Bosch Satellite H2 Clinic Hakata, Fukuoka, Japan
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20
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Gusic M, Schottmann G, Feichtinger RG, Du C, Scholz C, Wagner M, Mayr JA, Lee CY, Yépez VA, Lorenz N, Morales-Gonzalez S, Panneman DM, Rötig A, Rodenburg RJT, Wortmann SB, Prokisch H, Schuelke M. Bi-Allelic UQCRFS1 Variants Are Associated with Mitochondrial Complex III Deficiency, Cardiomyopathy, and Alopecia Totalis. Am J Hum Genet 2020; 106:102-111. [PMID: 31883641 DOI: 10.1016/j.ajhg.2019.12.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 12/05/2019] [Indexed: 01/15/2023] Open
Abstract
Isolated complex III (CIII) deficiencies are among the least frequently diagnosed mitochondrial disorders. Clinical symptoms range from isolated myopathy to severe multi-systemic disorders with early death and disability. To date, we know of pathogenic variants in genes encoding five out of 10 subunits and five out of 13 assembly factors of CIII. Here we describe rare bi-allelic variants in the gene of a catalytic subunit of CIII, UQCRFS1, which encodes the Rieske iron-sulfur protein, in two unrelated individuals. Affected children presented with low CIII activity in fibroblasts, lactic acidosis, fetal bradycardia, hypertrophic cardiomyopathy, and alopecia totalis. Studies in proband-derived fibroblasts showed a deleterious effect of the variants on UQCRFS1 protein abundance, mitochondrial import, CIII assembly, and cellular respiration. Complementation studies via lentiviral transduction and overexpression of wild-type UQCRFS1 restored mitochondrial function and rescued the cellular phenotype, confirming UQCRFS1 variants as causative for CIII deficiency. We demonstrate that mutations in UQCRFS1 can cause mitochondrial disease, and our results thereby expand the clinical and mutational spectrum of CIII deficiencies.
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Affiliation(s)
- Mirjana Gusic
- Institute of Human Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Institute of Human Genetics, Technical University Munich, 81675 Munich, Germany
| | - Gudrun Schottmann
- Charité-Universitätsmedizin Berlin, corporate member of the Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health: NeuroCure Cluster of Excellence, 10117 Berlin, Germany; Charité-Universitätsmedizin Berlin, corporate member of the Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health: Department of Neuropediatrics, 13353 Berlin, Germany
| | - René G Feichtinger
- University Children's Hospital, Salzburger Landeskliniken (SALK) and Paracelsus Medical University (PMU), 5020 Salzburg, Austria
| | - Chen Du
- Institute of Human Genetics, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Caroline Scholz
- Institute of Human Genetics, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Matias Wagner
- Institute of Human Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Institute of Human Genetics, Technical University Munich, 81675 Munich, Germany; Institute of Neurogenomics, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Johannes A Mayr
- University Children's Hospital, Salzburger Landeskliniken (SALK) and Paracelsus Medical University (PMU), 5020 Salzburg, Austria
| | - Chae-Young Lee
- Charité-Universitätsmedizin Berlin, corporate member of the Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health: NeuroCure Cluster of Excellence, 10117 Berlin, Germany; Charité-Universitätsmedizin Berlin, corporate member of the Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health: Department of Neuropediatrics, 13353 Berlin, Germany
| | - Vicente A Yépez
- Department of Informatics, Technical University of Munich, 81371 Garching, Germany
| | - Norbert Lorenz
- Department of Pediatric Cardiology, Municipal Hospital Dresden, 01307 Dresden, Germany
| | - Susanne Morales-Gonzalez
- Charité-Universitätsmedizin Berlin, corporate member of the Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health: NeuroCure Cluster of Excellence, 10117 Berlin, Germany; Charité-Universitätsmedizin Berlin, corporate member of the Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health: Department of Neuropediatrics, 13353 Berlin, Germany
| | - Daan M Panneman
- Radboud Center for Mitochondrial Disorders, Department of Pediatrics, Radboud UMC, Nijmegen 6525, the Netherlands
| | - Agnès Rötig
- UMR 1163, Université Paris Descartes, Sorbonne Paris Cité, Institut IMAGINE, 24 Boulevard du Montparnasse, 75015 Paris, France
| | - Richard J T Rodenburg
- Radboud Center for Mitochondrial Disorders, Department of Pediatrics, Radboud UMC, Nijmegen 6525, the Netherlands
| | - Saskia B Wortmann
- Institute of Human Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Institute of Human Genetics, Technical University Munich, 81675 Munich, Germany; University Children's Hospital, Salzburger Landeskliniken (SALK) and Paracelsus Medical University (PMU), 5020 Salzburg, Austria
| | - Holger Prokisch
- Institute of Human Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Institute of Human Genetics, Technical University Munich, 81675 Munich, Germany
| | - Markus Schuelke
- Charité-Universitätsmedizin Berlin, corporate member of the Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health: NeuroCure Cluster of Excellence, 10117 Berlin, Germany; Charité-Universitätsmedizin Berlin, corporate member of the Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health: Department of Neuropediatrics, 13353 Berlin, Germany.
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21
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Tacchino F, Succurro A, Ebenhöh O, Gerace D. Optimal efficiency of the Q-cycle mechanism around physiological temperatures from an open quantum systems approach. Sci Rep 2019; 9:16657. [PMID: 31723177 PMCID: PMC6853958 DOI: 10.1038/s41598-019-52842-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 10/14/2019] [Indexed: 01/17/2023] Open
Abstract
The Q-cycle mechanism entering the electron and proton transport chain in oxygenic photosynthesis is an example of how biological processes can be efficiently investigated with elementary microscopic models. Here we address the problem of energy transport across the cellular membrane from an open quantum system theoretical perspective. We model the cytochrome \documentclass[12pt]{minimal}
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\begin{document}$${b}_{6}\,f$$\end{document}b6f protein complex under cyclic electron flow conditions starting from a simplified kinetic model, which is hereby revisited in terms of a Markovian quantum master equation formulation and spin-boson Hamiltonian treatment. We apply this model to theoretically demonstrate an optimal thermodynamic efficiency of the Q-cycle around ambient and physiologically relevant temperature conditions. Furthermore, we determine the quantum yield of this complex biochemical process after setting the electrochemical potentials to values well established in the literature. The present work suggests that the theory of quantum open systems can successfully push forward our theoretical understanding of complex biological systems working close to the quantum/classical boundary.
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Affiliation(s)
| | - Antonella Succurro
- Institute of Quantitative and Theoretical Biology, Heinrich Heine University, 40225, Düsseldorf, Germany.,Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University, 40225, Düsseldorf, Germany.,Life and Medical Sciences (LIMES) Institute and West German Genome Center, University of Bonn, Bonn, Germany
| | - Oliver Ebenhöh
- Institute of Quantitative and Theoretical Biology, Heinrich Heine University, 40225, Düsseldorf, Germany.,Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University, 40225, Düsseldorf, Germany
| | - Dario Gerace
- Department of Physics, University of Pavia, I-27100, Pavia, Italy.
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22
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Hoang NH, Strogolova V, Mosley JJ, Stuart RA, Hosler J. Hypoxia-inducible gene domain 1 proteins in yeast mitochondria protect against proton leak through complex IV. J Biol Chem 2019; 294:17669-17677. [PMID: 31591265 DOI: 10.1074/jbc.ra119.010317] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 09/26/2019] [Indexed: 01/27/2023] Open
Abstract
Hypoxia-inducible gene domain 1 (HIGD1) proteins are small integral membrane proteins, conserved from bacteria to humans, that associate with oxidative phosphorylation supercomplexes. Using yeast as a model organism, we have shown previously that its two HIGD1 proteins, Rcf1 and Rcf2, are required for the generation and maintenance of a normal membrane potential (ΔΨ) across the inner mitochondrial membrane (IMM). We postulated that the lower ΔΨ observed in the absence of the HIGD1 proteins may be due to decreased proton pumping by complex IV (CIV) or enhanced leak of protons across the IMM. Here we measured the ΔΨ generated by complex III (CIII) to discriminate between these possibilities. First, we found that the decreased ΔΨ observed in the absence of the HIGD1 proteins cannot be due to decreased proton pumping by CIV because CIII, operating alone, also exhibited a decreased ΔΨ when HIGD1 proteins were absent. Because CIII can neither lower its pumping stoichiometry nor transfer protons completely across the IMM, this result indicates that HIGD1 protein ablation enhances proton leak across the IMM. Second, we demonstrate that this proton leak occurs through CIV because ΔΨ generation by CIII is restored when CIV is removed from the cell. Third, the proton leak appeared to take place through an inactive population of CIV that accumulates when HIGD1 proteins are absent. We conclude that HIGD1 proteins in yeast prevent CIV inactivation, likely by preventing the loss of lipids bound within the Cox3 protein of CIV.
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Affiliation(s)
- Ngoc H Hoang
- Department of Cell and Molecular Biology, University of Mississippi Medical Center, Jackson, Mississippi 39216
| | - Vera Strogolova
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin 53233
| | - Jaramys J Mosley
- Department of Cell and Molecular Biology, University of Mississippi Medical Center, Jackson, Mississippi 39216
| | - Rosemary A Stuart
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin 53233
| | - Jonathan Hosler
- Department of Cell and Molecular Biology, University of Mississippi Medical Center, Jackson, Mississippi 39216
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23
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Cramer WA. Structure-function of the cytochrome b 6f lipoprotein complex: a scientific odyssey and personal perspective. PHOTOSYNTHESIS RESEARCH 2019; 139:53-65. [PMID: 30311133 PMCID: PMC6510485 DOI: 10.1007/s11120-018-0585-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 09/15/2018] [Indexed: 05/04/2023]
Abstract
Structure-function studies of the cytochrome b6f complex, the central hetero-oligomeric membrane protein complex in the electron transport chain of oxygenic photosynthesis, which formed the basis for a high-resolution (2.5 Å) crystallographic solution of the complex, are described. Structure-function differences between the structure of subunits of the bc complexes, b6f, and bc1 from mitochondria and photosynthetic bacteria, which are often assumed to function identically, are discussed. Major differences which suggest that quinone-dependent electron transport pathways can vary in b6f and bc1 complexes are as follows: (a) an additional c-type heme, cn, and bound single copies of chlorophyll a and β-carotene in the b6f complex; and (b) a cyclic electron transport pathway that encompasses the b6f and PSI reaction center complexes. The importance of including lipid in crystallization of the cytochrome complex, or with any hetero-oligomeric membrane protein complex, is emphasized, and consequences to structure-function of b6f being a lipoprotein complex discussed, including intra-protein dielectric heterogeneity and resultant pathways of trans-membrane electron transport. The role of the b6f complex in trans-membrane signal transduction from reductant generated on the p-side of the electron transport chain to the regulation of light energy to the two photosystems by trans-side phosphorylation of the light-harvesting chlorophyll protein is presented. Regarding structure aspects relevant to plastoquinol-quinone entrance-egress: (i) modification of the p-side channel for plastoquinone access to the iron-sulfur protein would change the rate-limiting step in electron transport; (ii) the narrow niche for entry of plastoquinol into b6f from the PSII reaction center complex would seem to require close proximity between the complexes.
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Affiliation(s)
- William A Cramer
- Department of Biological Sciences, Purdue University, Hockmeyer Building for Structural Biology, West Lafayette, IN, 47907, USA.
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24
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Zhang W, Niu C, Liu Y, Storey KB. Positive or negative? The shell alters the relationship among behavioral defense strategy, energy metabolic levels and antioxidant capacity in freshwater turtles. Front Zool 2019; 16:3. [PMID: 30809267 PMCID: PMC6375210 DOI: 10.1186/s12983-019-0301-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 01/23/2019] [Indexed: 11/10/2022] Open
Abstract
Background The relationships among energy metabolic levels, behavioral and other physiological traits help to determine the trade-off of energy allocation between different traits and the evolution of life-history driven by natural selection. However, these relationships may be distinctive in selected animal taxa because of their unique traits. In the present study, the relationships among energy metabolic levels, behavioral defense strategies, and antioxidant capacity were explored in three freshwater turtle species with different shell morphologies, by assessing responses to attack, righting time, shell morphology, whole-organism metabolic rates, tissue metabolic enzyme activities and antioxidant levels. Results The Chinese three-keeled pond turtles, Chinemys reevesii, showed a passive defense strategy, relatively larger shells, a higher resting metabolic rate (RMR) and higher antioxidant levels compared to the snapping turtle, Chelydra serpentina, or the Chinese soft-shelled turtle, Pelodiscus sinensis. These latter two species both showed an active defense strategy, a higher factorial aerobic scope and better muscle anaerobic metabolic capacity but relatively smaller shells, lower RMR and antioxidant capacity. Conclusion Our results indicate a negative relationship between RMR and activity levels in behavioral defense strategies along small-big shell continuum among the three turtle species. We also found a positive relationship between antioxidant capacity and energy metabolism but a negative one between antioxidant capacity and activity levels in defense strategies. The present study indicated a role of turtle shell in forming unique relationship between energy metabolic levels and behaviors in freshwater turtle taxa and a possible trade-off between the maintenance of physiological homeostasis and activity levels in energy allocation.
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Affiliation(s)
- Wenyi Zhang
- 1Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, 100875 China.,2State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102 People's Republic of China
| | - Cuijuan Niu
- 1Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, 100875 China
| | - Yukun Liu
- 1Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, 100875 China
| | - Kenneth B Storey
- 3Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6 Canada
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25
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Mailloux RJ. Cysteine Switches and the Regulation of Mitochondrial Bioenergetics and ROS Production. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1158:197-216. [PMID: 31452142 DOI: 10.1007/978-981-13-8367-0_11] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Mitochondria are dynamic organelles that perform a number of interconnected tasks that are elegantly intertwined with the regulation of cell functions. This includes the provision of ATP, reactive oxygen species (ROS), and building blocks for the biosynthesis of macromolecules while also serving as signaling platforms for the cell. Although the functions executed by mitochondria are complex, at its core these roles are, to a certain degree, fulfilled by electron transfer reactions and the establishment of a protonmotive force (PMF). Indeed, mitochondria are energy conserving organelles that extract electrons from nutrients to establish a PMF, which is then used to drive ATP and NADPH production, solute import, and many other functions including the propagation of cell signals. These same electrons extracted from nutrients are also used to produce ROS, pro-oxidants that can have potentially damaging effects at high levels, but also serve as secondary messengers at low amounts. Mitochondria are also enriched with antioxidant defenses, which are required to buffer cellular ROS. These same redox buffering networks also fulfill another important role; regulation of proteins through the reversible oxidation of cysteine switches. The modification of cysteine switches with the antioxidant glutathione, a process called protein S-glutathionylation, has been found to play an integral role in controlling various mitochondrial functions. In addition, recent findings have demonstrated that disrupting mitochondrial protein S-glutathionylation reactions can have some dire pathological consequences. Accordingly, this chapter focuses on the role of mitochondrial cysteine switches in the modulation of different physiological functions and how defects in these pathways contribute to the development of disease.
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Affiliation(s)
- Ryan J Mailloux
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL, Canada.
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26
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Zhou PK, Huang RX. Targeting of the respiratory chain by toxicants: beyond the toxicities to mitochondrial morphology. Toxicol Res (Camb) 2018; 7:1008-1011. [PMID: 30542598 PMCID: PMC6249626 DOI: 10.1039/c8tx00207j] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 09/25/2018] [Indexed: 12/11/2022] Open
Abstract
The mitochondrion is an important subcellular target of environmental toxicants. With environmental stress, a series of toxic effects on mitochondria are induced, which originate from the dynamic changes of mitochondrial fusion and fission, structure/membrane damage, and respiratory chain dysfunction. The toxic effects of various toxicants on mitochondrial morphology and intact membranes, and their determination of cell fate, have already been broadly studied and reported on. However, their effects on the integrity and function of the mitochondrial respiratory chain (RC) remain incompletely understood. Recently, Fan et al. and Yu et al. approached this topic by closely examining the mitochondrial toxicities, including the effect on the respiratory chain, induced by organic arsenical chemical 2-methoxy-4-(((4-(oxoarsanyl)phenyl)imino)methyl)phenol and thiourea gold(i) complexes (AuTuCl). Obviously, toxicant-induced dysfunction of the respiratory chain can hinder ATP production, and may elevate ROS generation. The increased ROS can further damage mtDNA, and consequently leads to inactivation of some RC protein-encoding mtDNA, generating a vicious circle of amplifying mitochondrial damage. We hope that these studies focused on RC structure and activity will broaden our view of mitochondrial toxicology and draw forth more profound mechanistic studies on the respiratory chain toxicity of environmental toxicants and their application in risk assessment.
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Affiliation(s)
- P K Zhou
- Department of Radiation Biology , Beijing Key Laboratory for Radiobiology , Beijing Institute of Radiation Medicine , AMMS , Beijing 100850 , P. R. China .
| | - R X Huang
- Department of Occupational and Environmental Health , Central south University , Changsha , 410078 , China .
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27
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Signes A, Fernandez-Vizarra E. Assembly of mammalian oxidative phosphorylation complexes I-V and supercomplexes. Essays Biochem 2018; 62:255-270. [PMID: 30030361 PMCID: PMC6056720 DOI: 10.1042/ebc20170098] [Citation(s) in RCA: 141] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 05/08/2018] [Accepted: 05/11/2018] [Indexed: 01/30/2023]
Abstract
The assembly of the five oxidative phosphorylation system (OXPHOS) complexes in the inner mitochondrial membrane is an intricate process. The human enzymes comprise core proteins, performing the catalytic activities, and a large number of 'supernumerary' subunits that play essential roles in assembly, regulation and stability. The correct addition of prosthetic groups as well as chaperoning and incorporation of the structural components require a large number of factors, many of which have been found mutated in cases of mitochondrial disease. Nowadays, the mechanisms of assembly for each of the individual complexes are almost completely understood and the knowledge about the assembly factors involved is constantly increasing. On the other hand, it is now well established that complexes I, III and IV interact with each other, forming the so-called respiratory supercomplexes or 'respirasomes', although the pathways that lead to their formation are still not completely clear. This review is a summary of our current knowledge concerning the assembly of complexes I-V and of the supercomplexes.
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Affiliation(s)
- Alba Signes
- MRC-Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, U.K
| | - Erika Fernandez-Vizarra
- MRC-Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, U.K.
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28
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Fernandez-Vizarra E, Zeviani M. Mitochondrial complex III Rieske Fe-S protein processing and assembly. Cell Cycle 2018; 17:681-687. [PMID: 29243944 DOI: 10.1080/15384101.2017.1417707] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Regulation of the mitochondrial respiratory chain biogenesis is a matter of great interest because of its implications for mitochondrial disease. One of the mitochondrial disease genes recently discovered associated to encephalopathy and mitochondrial complex III (cIII) deficiency is TTC19. Our study of TTC19-deficient human and mouse models, has led us to propose a post-assembly quality control role or 'husbandry' function for this factor that is linked to Rieske Fe-S protein (UQCRFS1). UQCRFS1 is the last incorporated cIII subunit, and its presence is essential for enzymatic activity. During UQCRFS1 assembly, the precursor is cleaved and its N-terminal part remains bound to the complex, between the two core subunits (UQCRC1 and UQCRC2). In the absence of TTC19 there is a prominent accumulation of these UQCRFS1-derived N-terminal fragments that proved to be detrimental for cIII function. In this article we will discuss some ideas around the UQCRFS1 processing and assembly and its importance for the regulation of cIII activity and biogenesis.
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Affiliation(s)
- Erika Fernandez-Vizarra
- a MRC-Mitochondrial Biology Unit , University of Cambridge , Hills Road, CB2 0XY , Cambridge , UK
| | - Massimo Zeviani
- a MRC-Mitochondrial Biology Unit , University of Cambridge , Hills Road, CB2 0XY , Cambridge , UK
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29
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Differential Alterations of the Mitochondrial Morphology and Respiratory Chain Complexes during Postnatal Development of the Mouse Lung. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:9169146. [PMID: 29430286 PMCID: PMC5753018 DOI: 10.1155/2017/9169146] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 09/28/2017] [Indexed: 11/18/2022]
Abstract
Mitochondrial biogenesis and adequate energy production in various organs of mammals are necessary for postnatal adaptation to extrauterine life in an environment with high oxygen content. Even though transgenic mice are frequently used as experimental models, to date, no combined detailed molecular and morphological analysis on the mitochondrial compartment in different lung cell types has been performed during postnatal mouse lung development. In our study, we revealed a significant upregulation of most mitochondrial respiratory complexes at protein and mRNA levels in the lungs of P15 and adult animals in comparison to newborns. The majority of adult animal samples showed the strongest increase, except for succinate dehydrogenase protein (SDHD). Likewise, an increase in mRNA expression for mtDNA transcription machinery genes (Polrmt, Tfam, Tfb1m, and Tfb2m), mitochondrially encoded RNA (mt-Rnr1 and mt-Rnr2), and the nuclear-encoded mitochondrial DNA polymerase (POLG) was observed. The biochemical and molecular results were corroborated by a parallel increase of mitochondrial number, size, cristae number, and complexity, exhibiting heterogeneous patterns in distinct bronchiolar and alveolar epithelial cells. Taken together, our results suggest a specific adaptation and differential maturation of the mitochondrial compartment according to the metabolic needs of individual cell types during postnatal development of the mouse lung.
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30
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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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31
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Letts JA, Sazanov LA. Clarifying the supercomplex: the higher-order organization of the mitochondrial electron transport chain. Nat Struct Mol Biol 2017; 24:800-808. [PMID: 28981073 DOI: 10.1038/nsmb.3460] [Citation(s) in RCA: 220] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 08/03/2017] [Indexed: 12/27/2022]
Abstract
The oxidative phosphorylation electron transport chain (OXPHOS-ETC) of the inner mitochondrial membrane is composed of five large protein complexes, named CI-CV. These complexes convert energy from the food we eat into ATP, a small molecule used to power a multitude of essential reactions throughout the cell. OXPHOS-ETC complexes are organized into supercomplexes (SCs) of defined stoichiometry: CI forms a supercomplex with CIII2 and CIV (SC I+III2+IV, known as the respirasome), as well as with CIII2 alone (SC I+III2). CIII2 forms a supercomplex with CIV (SC III2+IV) and CV forms dimers (CV2). Recent cryo-EM studies have revealed the structures of SC I+III2+IV and SC I+III2. Furthermore, recent work has shed light on the assembly and function of the SCs. Here we review and compare these recent studies and discuss how they have advanced our understanding of mitochondrial electron transport.
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Affiliation(s)
- James A Letts
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Leonid A Sazanov
- Institute of Science and Technology Austria, Klosterneuburg, Austria
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32
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Iommarini L, Ghelli A, Leone G, Tropeano CV, Kurelac I, Amato LB, Gasparre G, Porcelli AM. Mild phenotypes and proper supercomplex assembly in human cells carrying the homoplasmic m.15557G > A mutation in cytochrome b gene. Hum Mutat 2017; 39:92-102. [PMID: 28967163 DOI: 10.1002/humu.23350] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 09/25/2017] [Accepted: 09/27/2017] [Indexed: 12/14/2022]
Abstract
Respiratory complex III (CIII) is the first enzymatic bottleneck of the mitochondrial respiratory chain both in its native dimeric form and in supercomplexes. The mammalian CIII comprises 11 subunits among which cytochrome b is central in the catalytic core, where oxidation of ubiquinol occurs at the Qo site. The Qo- or PEWY-motif of cytochrome b is the most conserved through species. Importantly, the highly conserved glutamate at position 271 (Glu271) has never been studied in higher eukaryotes so far and its role in the Q-cycle remains debated. Here, we showed that the homoplasmic m.15557G > A/MT-CYB, which causes the p.Glu271Lys amino acid substitution predicted to dramatically affect CIII, induces a mild mitochondrial dysfunction in human transmitochondrial cybrids. Indeed, we found that the severity of such mutation is mitigated by the proper assembly of CIII into supercomplexes, which may favor an optimal substrate channeling and buffer superoxide production in vitro.
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Affiliation(s)
- Luisa Iommarini
- Dipartimento di Farmacia e Biotecnologie (FABIT), Università di Bologna, Bologna, Italy
| | - Anna Ghelli
- Dipartimento di Farmacia e Biotecnologie (FABIT), Università di Bologna, Bologna, Italy
| | - Giulia Leone
- Dipartimento di Farmacia e Biotecnologie (FABIT), Università di Bologna, Bologna, Italy
| | | | - Ivana Kurelac
- Dipartimento di Scienze Mediche e Chirurgiche (DIMEC), U.O. Genetica Medica, Pol. Universitario S. Orsola-Malpighi, Università di Bologna, Bologna, Italy
| | - Laura Benedetta Amato
- Dipartimento di Scienze Mediche e Chirurgiche (DIMEC), U.O. Genetica Medica, Pol. Universitario S. Orsola-Malpighi, Università di Bologna, Bologna, Italy
| | - Giuseppe Gasparre
- Dipartimento di Scienze Mediche e Chirurgiche (DIMEC), U.O. Genetica Medica, Pol. Universitario S. Orsola-Malpighi, Università di Bologna, Bologna, Italy
| | - Anna Maria Porcelli
- Dipartimento di Farmacia e Biotecnologie (FABIT), Università di Bologna, Bologna, Italy.,Centro Interdipartimentale di Ricerca Industriale Scienze della Vita e Tecnologie per la Salute, Università di Bologna, Bologna, Italy
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33
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Głombik K, Stachowicz A, Trojan E, Olszanecki R, Ślusarczyk J, Suski M, Chamera K, Budziszewska B, Lasoń W, Basta-Kaim A. Evaluation of the effectiveness of chronic antidepressant drug treatments in the hippocampal mitochondria - A proteomic study in an animal model of depression. Prog Neuropsychopharmacol Biol Psychiatry 2017; 78:51-60. [PMID: 28526399 DOI: 10.1016/j.pnpbp.2017.05.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 05/09/2017] [Accepted: 05/16/2017] [Indexed: 12/31/2022]
Abstract
Several lines of evidence indicate that adverse experience in early life may be a triggering factor for disturbances in the brain mitochondrial proteins and lead to the development of depression in adulthood. On the other hand, little is known about the impact of chronic administration of various antidepressant drugs on the brain mitochondria, as a target for the pharmacotherapy of depression. The purpose of our study was to compare the impact of chronic treatment with two antidepressant drugs with different mechanisms of action, a tricyclic antidepressant (TCA), imipramine, and an antidepressant of the selective serotonin reuptake inhibitor (SSRI) class, fluoxetine, on the mitochondria-enriched subproteome profile in the hippocampus of 3-month-old male rats following a prenatal stress procedure (an animal model of depression). We clearly confirmed that chronic imipramine and fluoxetine administration not only normalized depression-like disturbances evoked by the prenatal stress procedure but also modulated the mitochondria-enriched subproteome profile in the hippocampus of adult offspring rats. In line with this, two-dimensional electrophoresis coupled with mass spectrometry showed a statistically significant down-regulation of 14-3-3 and cytochrome bc1 proteins and an up-regulation of COP9 signalosome expression after chronic imipramine treatment in the hippocampus of prenatally stressed offspring. Fluoxetine administration strongly up-regulated the expression of cathepsin D, one of the key proteins involved in the prevention of the development of neurodegenerative processes. Furthermore, this antidepressant treatment enhanced expression of proteins engaged in the improvement of learning and memory processes (STMN1, Dnm-1) as well as in mitochondrial biogenesis and defense against oxidative stress (DJ-1). These findings provide new evidence that chronic administration of antidepressants exerts a varied impact on the mitochondria-enriched subproteome in the hippocampus of adult rats following a prenatal stress procedure. In particular, the effect of fluoxetine requires additional experiments to elucidate the possible beneficial biological consequences underlying the effects mediated by this antidepressant.
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Affiliation(s)
- Katarzyna Głombik
- Department of Experimental Neuroendocrinology, Institute of Pharmacology, Polish Academy of Sciences, 12 Smętna St, 31-343 Kraków, Poland
| | - Aneta Stachowicz
- Chair of Pharmacology, Jagiellonian University Medical College, 16 Grzegórzecka Street, 31-531 Kraków, Poland
| | - Ewa Trojan
- Department of Experimental Neuroendocrinology, Institute of Pharmacology, Polish Academy of Sciences, 12 Smętna St, 31-343 Kraków, Poland
| | - Rafał Olszanecki
- Chair of Pharmacology, Jagiellonian University Medical College, 16 Grzegórzecka Street, 31-531 Kraków, Poland
| | - Joanna Ślusarczyk
- Department of Experimental Neuroendocrinology, Institute of Pharmacology, Polish Academy of Sciences, 12 Smętna St, 31-343 Kraków, Poland
| | - Maciej Suski
- Chair of Pharmacology, Jagiellonian University Medical College, 16 Grzegórzecka Street, 31-531 Kraków, Poland
| | - Katarzyna Chamera
- Department of Experimental Neuroendocrinology, Institute of Pharmacology, Polish Academy of Sciences, 12 Smętna St, 31-343 Kraków, Poland
| | - Bogusława Budziszewska
- Department of Experimental Neuroendocrinology, Institute of Pharmacology, Polish Academy of Sciences, 12 Smętna St, 31-343 Kraków, Poland
| | - Władysław Lasoń
- Department of Experimental Neuroendocrinology, Institute of Pharmacology, Polish Academy of Sciences, 12 Smętna St, 31-343 Kraków, Poland
| | - Agnieszka Basta-Kaim
- Department of Experimental Neuroendocrinology, Institute of Pharmacology, Polish Academy of Sciences, 12 Smętna St, 31-343 Kraków, Poland.
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34
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Papa S, Capitanio G, Papa F. The mechanism of coupling between oxido-reduction and proton translocation in respiratory chain enzymes. Biol Rev Camb Philos Soc 2017. [DOI: 10.1111/brv.12347] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Sergio Papa
- Department of Basic Medical Sciences, Neurosciences and Sense Organs (BMSNSO), Section of Medical Biochemistry; University of Bari ‘Aldo Moro’; Piazza G. Cesare 11 70124 Bari Italy
- Institute of Biomembranes and Bioenergetics; National Research Council at BMSNSO; Piazza G. Cesare 11 70124 Bari Italy
| | - Giuseppe Capitanio
- Department of Basic Medical Sciences, Neurosciences and Sense Organs (BMSNSO), Section of Medical Biochemistry; University of Bari ‘Aldo Moro’; Piazza G. Cesare 11 70124 Bari Italy
| | - Francesco Papa
- Department of Basic Medical Sciences, Neurosciences and Sense Organs (BMSNSO), Section of Medical Biochemistry; University of Bari ‘Aldo Moro’; Piazza G. Cesare 11 70124 Bari Italy
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35
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Crofts AR, Rose SW, Burton RL, Desai AV, Kenis PJA, Dikanov SA. The Q-Cycle Mechanism of the bc1 Complex: A Biologist’s Perspective on Atomistic Studies. J Phys Chem B 2017; 121:3701-3717. [DOI: 10.1021/acs.jpcb.6b10524] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Antony R. Crofts
- Department
of Biochemistry, University of Illinois at Urbana−Champaign, 419 Roger Adams Lab, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
- Center
for Biophysics and Quantitative Biology, University of Illinois at Urbana−Champaign, 179 Loomis, 1110 West Green Street, Urbana, Illinois 61801, United States
| | - Stuart W. Rose
- Center
for Biophysics and Quantitative Biology, University of Illinois at Urbana−Champaign, 179 Loomis, 1110 West Green Street, Urbana, Illinois 61801, United States
| | - Rodney L. Burton
- Department
of Biochemistry, University of Illinois at Urbana−Champaign, 419 Roger Adams Lab, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Amit V. Desai
- Department of Chemical & Biomolecular Engineering, University of Illinois at Urbana−Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Paul J. A. Kenis
- Department of Chemical & Biomolecular Engineering, University of Illinois at Urbana−Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Sergei A. Dikanov
- Department
of Veterinary Clinical Medicine, University of Illinois at Urbana−Champaign, 1008 West Hazelwood Drive, Urbana, Illinois 61801, United States
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36
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Geiss AF, Khandelwal R, Baurecht D, Bliem C, Reiner-Rozman C, Boersch M, Ullmann GM, Loew LM, Naumann RLC. pH and Potential Transients of the bc 1 Complex Co-Reconstituted in Proteo-Lipobeads with the Reaction Center from Rb. sphaeroides. J Phys Chem B 2017; 121:143-152. [PMID: 27992230 DOI: 10.1021/acs.jpcb.6b11116] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
His-tag technology is employed to bind membrane proteins, such as the bc1 complex and the reaction center (RC) from Rhodobacter sphaeroides, to spherical as well as planar surfaces in a strict orientation. Subsequently, the spherical and planar surfaces are subjected to in situ dialysis to form proteo-lipobeads (PLBs) and protein-tethered bilayer membranes, respectively. PLBs based on Ni-nitrileotriacetic acid-functionalized agarose beads that have diameters ranging from 50 to 150 μm are used to assess proton release and membrane potential parameters by confocal laser-scanning microscopy. The pH and potential transients are thus obtained from bc1 activated by the RC. To assess the turnover of bc1 excited by the RC in a similar setting, we used the planar surface of an attenuated total reflection crystal modified with a thin gold layer to carry out time-resolved surface-enhanced IR absorption spectroscopy triggered by flash lamp excitation. The experiments suggest that both proteins interact in a cyclic manner in both environments. The activity of the proteins seems to be preserved in the same manner as that in chromatophores or reconstituted in liposomes.
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Affiliation(s)
- Andreas F Geiss
- Biosensor Technologies, Austrian Institute of Technology GmbH, AIT , Donau-City Street 1, 1220 Vienna, Austria.,University of Natural Resources and Life Sciences , Gregor-Mendel-Straße 33, 1180 Wien, Austria
| | - Raghav Khandelwal
- Indian Institute of Technology Kanpur , Kalyanpur, Kanpur, Uttar Pradesh 208016, India
| | - Dieter Baurecht
- Faculty of Chemistry, Department of Physical Chemistry, University of Vienna , Währinger Straße 42, 1090 Vienna, Austria
| | - Christina Bliem
- Biosensor Technologies, Austrian Institute of Technology GmbH, AIT , Donau-City Street 1, 1220 Vienna, Austria.,Center of Electrochemical Surface Technology, CEST , Viktor-Kaplan-Str. 2, 2700 Wiener Neustadt, Austria
| | - Ciril Reiner-Rozman
- Biosensor Technologies, Austrian Institute of Technology GmbH, AIT , Donau-City Street 1, 1220 Vienna, Austria.,Center of Electrochemical Surface Technology, CEST , Viktor-Kaplan-Str. 2, 2700 Wiener Neustadt, Austria
| | - Michael Boersch
- Single-Molecule Microscopy Group, Jena University Hospital , Nonnenplan 2-4, 07743 Jena, Germany
| | - G Matthias Ullmann
- Computational Biochemistry Group, University of Bayreuth , Universitätsstraße 30, NWI, 95447 Bayreuth, Germany
| | - Leslie M Loew
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut Health Center , Farmington, Connecticut 06030, United States
| | - Renate L C Naumann
- Biosensor Technologies, Austrian Institute of Technology GmbH, AIT , Donau-City Street 1, 1220 Vienna, Austria
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37
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Salo AB, Husen P, Solov’yov IA. Charge Transfer at the Qo-Site of the Cytochrome bc1 Complex Leads to Superoxide Production. J Phys Chem B 2016; 121:1771-1782. [DOI: 10.1021/acs.jpcb.6b10403] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Adrian Bøgh Salo
- Department of Physics,
Chemistry
and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Peter Husen
- Department of Physics,
Chemistry
and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Ilia A. Solov’yov
- Department of Physics,
Chemistry
and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
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38
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Manickam P, Kaushik A, Karunakaran C, Bhansali S. Recent advances in cytochrome c biosensing technologies. Biosens Bioelectron 2016; 87:654-668. [PMID: 27619529 DOI: 10.1016/j.bios.2016.09.013] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 08/31/2016] [Accepted: 09/02/2016] [Indexed: 11/27/2022]
Abstract
This review is an attempt, for the first time, to describe advancements in sensing technology for cytochrome c (cyt c) detection, at point-of-care (POC) application. Cyt c, a heme containing metalloprotein is located in the intermembrane space of mitochondria and released into bloodstream during pathological conditions. The release of cyt c from mitochondria is a key initiative step in the activation of cell death pathways. Circulating cyt c levels represents a novel in-vivo marker of mitochondrial injury after resuscitation from heart failure and chemotherapy. Thus, cyt c detection is not only serving as an apoptosis biomarker, but also is of great importance to understand certain diseases at cellular level. Various existing techniques such as enzyme-linked immunosorbent assays (ELISA), Western blot, high performance liquid chromatography (HPLC), spectrophotometry and flow cytometry have been used to estimate cyt c. However, the implementation of these techniques at POC application is limited due to longer analysis time, expensive instruments and expertise needed for operation. To overcome these challenges, significant efforts are being made to develop electrochemical biosensing technologies for fast, accurate, selective, and sensitive detection of cyt c. Presented review describes the cutting edge technologies available in the laboratories to detect cyt c. The recent advancements in designing and development of electrochemical cyt c biosensors for the quantification of cyt c are also discussed. This review also highlights the POC cyt c biosensors developed recently, that would prove of interest to biologist and therapist to get real time informatics needed to evaluate death process, diseases progression, therapeutics and processes related with mitochondrial injury.
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Affiliation(s)
- Pandiaraj Manickam
- Bio-MEMS and Microsystems Laboratory, Department of Electrical and Computer Engineering, Florida International University, Miami, FL, USA.
| | - Ajeet Kaushik
- Center for Personalized Nanomedicine, Institute of Neuro immune Pharmacology, Department of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
| | - Chandran Karunakaran
- Biomedical Research Laboratory, Department of Chemistry, VHNSN College (Autonomous), Virudhunagar, Tamil Nadu, India
| | - Shekhar Bhansali
- Bio-MEMS and Microsystems Laboratory, Department of Electrical and Computer Engineering, Florida International University, Miami, FL, USA
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Senge MO, MacGowan SA, O'Brien JM. Conformational control of cofactors in nature - the influence of protein-induced macrocycle distortion on the biological function of tetrapyrroles. Chem Commun (Camb) 2016; 51:17031-63. [PMID: 26482230 DOI: 10.1039/c5cc06254c] [Citation(s) in RCA: 135] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Tetrapyrrole-containing proteins are one of the most fundamental classes of enzymes in nature and it remains an open question to give a chemical rationale for the multitude of biological reactions that can be catalyzed by these pigment-protein complexes. There are many fundamental processes where the same (i.e., chemically identical) porphyrin cofactor is involved in chemically quite distinct reactions. For example, heme is the active cofactor for oxygen transport and storage (hemoglobin, myoglobin) and for the incorporation of molecular oxygen in organic substrates (cytochrome P450). It is involved in the terminal oxidation (cytochrome c oxidase) and the metabolism of H2O2 (catalases and peroxidases) and catalyzes various electron transfer reactions in cytochromes. Likewise, in photosynthesis the same chlorophyll cofactor may function as a reaction center pigment (charge separation) or as an accessory pigment (exciton transfer) in light harvesting complexes (e.g., chlorophyll a). Whilst differences in the apoprotein sequences alone cannot explain the often drastic differences in physicochemical properties encountered for the same cofactor in diverse protein complexes, a critical factor for all biological functions must be the close structural interplay between bound cofactors and the respective apoprotein in addition to factors such as hydrogen bonding or electronic effects. Here, we explore how nature can use the same chemical molecule as a cofactor for chemically distinct reactions using the concept of conformational flexibility of tetrapyrroles. The multifaceted roles of tetrapyrroles are discussed in the context of the current knowledge on distorted porphyrins. Contemporary analytical methods now allow a more quantitative look at cofactors in protein complexes and the development of the field is illustrated by case studies on hemeproteins and photosynthetic complexes. Specific tetrapyrrole conformations are now used to prepare bioengineered designer proteins with specific catalytic or photochemical properties.
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Affiliation(s)
- Mathias O Senge
- School of Chemistry, SFI Tetrapyrrole Laboratory, Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse Street, Dublin 2, Ireland and Medicinal Chemistry, Institute of Molecular Medicine, Trinity Centre for Health Sciences, Trinity College Dublin, St. James's Hospital, Dublin 8, Ireland.
| | - Stuart A MacGowan
- School of Chemistry, SFI Tetrapyrrole Laboratory, Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse Street, Dublin 2, Ireland
| | - Jessica M O'Brien
- Medicinal Chemistry, Institute of Molecular Medicine, Trinity Centre for Health Sciences, Trinity College Dublin, St. James's Hospital, Dublin 8, Ireland.
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40
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Dimer interface of bovine cytochrome c oxidase is influenced by local posttranslational modifications and lipid binding. Proc Natl Acad Sci U S A 2016; 113:8230-5. [PMID: 27364008 DOI: 10.1073/pnas.1600354113] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Bovine cytochrome c oxidase is an integral membrane protein complex comprising 13 protein subunits and associated lipids. Dimerization of the complex has been proposed; however, definitive evidence for the dimer is lacking. We used advanced mass spectrometry methods to investigate the oligomeric state of cytochrome c oxidase and the potential role of lipids and posttranslational modifications in its subunit interfaces. Mass spectrometry of the intact protein complex revealed that both the monomer and the dimer are stabilized by large lipid entities. We identified these lipid species from the purified protein complex, thus implying that they interact specifically with the enzyme. We further identified phosphorylation and acetylation sites of cytochrome c oxidase, located in the peripheral subunits and in the dimer interface, respectively. Comparing our phosphorylation and acetylation sites with those found in previous studies of bovine, mouse, rat, and human cytochrome c oxidase, we found that whereas some acetylation sites within the dimer interface are conserved, suggesting a role for regulation and stabilization of the dimer, phosphorylation sites were less conserved and more transient. Our results therefore provide insights into the locations and interactions of lipids with acetylated residues within the dimer interface of this enzyme, and thereby contribute to a better understanding of its structure in the natural membrane. Moreover dimeric cytochrome c oxidase, comprising 20 transmembrane, six extramembrane subunits, and associated lipids, represents the largest integral membrane protein complex that has been transferred via electrospray intact into the gas phase of a mass spectrometer, representing a significant technological advance.
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Cheng XF, Jiang C, Zhang M, Xia D, Chu LL, Wen YF, Zhu M, Jiang YG. Mycobacterial Interspersed Repetitive Unit Can Predict Drug Resistance of Mycobacterium tuberculosis in China. Front Microbiol 2016; 7:378. [PMID: 27047485 PMCID: PMC4803746 DOI: 10.3389/fmicb.2016.00378] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 03/08/2016] [Indexed: 11/23/2022] Open
Abstract
Background: Recently, Mycobacterial Interspersed Repetitive Unit (MIRU) was supposed to be associated with drug resistance in Mycobacterium tuberculosis (M. tuberculosis), but whether the association exists actually in local strains in China was still unknown. This research was conducted to explore that association and the predictability of MIRU to drug resistance of Tuberculosis (TB). Methods: The clinical isolates were collected and the susceptibility test were conducted with Lowenstein–Jensen (LJ) medium for five anti-TB drug. Based on PCR of MIRU-VNTR (Variable Number of Tandem Repeat) genotyping, we tested the number of the repeat unite of MIRU. Then, we used logistic regression to evaluate the association between 15 MIRU and drug resistance. In addition, we explored the most suitable MIRU locus of identified MIRU loci for drug resistance by multivariate logistic regression. Results: Of the 102 strains, one isolate was resistant to rifampicin and one isolate was resistant to streptomycin. Among these fifteen MIRU, there was a association between MIRU loci polymorphism and anti-tuberculosis drug resistance, ETRB (P = 0.03, OR = 0.19, 95% CI 0.05–0.81) and ETRC (P = 0.01, OR = 0.14, 95% CI 0.03–0.64) were negatively related to isoniazid resistance; MIRU20 (P = 0.05, OR = 2.87, 95% CI 1.01–8.12) was positively associated with ethambutol resistance; and QUB11a (P = 0.02, OR = 0.79, 95% CI 0.65–0.96) was a negative association factor of p-aminosalicylic acid resistance. Conclusion: Our research showed that MIRU loci may predict drug resistance of tuberculosis in China. However, the mechanism still needs further exploration.
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Affiliation(s)
- Xian-Feng Cheng
- School of Public Health, Wannan Medical CollegeWuhu, China; Clinical Laboratory, Institute of Dermatology, Chinese Academy of Medical Sciences - Peking Union Medical CollegeNanjing, China
| | - Chao Jiang
- School of Public Health, Wannan Medical College Wuhu, China
| | - Min Zhang
- Clinical Laboratory, Zhongda Hospital, School of Medicine, Southeast University Nanjing, China
| | - Dan Xia
- School of Public Health, Wannan Medical College Wuhu, China
| | - Li-Li Chu
- Pediatric Research Institute, Nanjing Children's Hospital, Nanjing Medical University Nanjing, China
| | - Yu-Feng Wen
- School of Public Health, Wannan Medical College Wuhu, China
| | - Ming Zhu
- Clinical Laboratory, Ma'anshan Center for Disease Control and Prevention Ma'anshan, China
| | - Yue-Gen Jiang
- Clinical Laboratory, Institute of Dermatology, Chinese Academy of Medical Sciences - Peking Union Medical CollegeNanjing, China; Clinical Laboratory, Ma'anshan Center for Disease Control and PreventionMa'anshan, China
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42
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Structure-Function of the Cytochrome b 6 f Lipoprotein Complex. ADVANCES IN PHOTOSYNTHESIS AND RESPIRATION 2016. [DOI: 10.1007/978-94-017-7481-9_9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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43
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Electron Transfer Reactions at the Qo Site of the Cytochrome bc 1 Complex: The Good, the Bad, and the Ugly. ADVANCES IN PHOTOSYNTHESIS AND RESPIRATION 2016. [DOI: 10.1007/978-94-017-7481-9_21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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44
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Akhmedov AT, Rybin V, Marín-García J. Mitochondrial oxidative metabolism and uncoupling proteins in the failing heart. Heart Fail Rev 2015; 20:227-49. [PMID: 25192828 DOI: 10.1007/s10741-014-9457-4] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Despite significant progress in cardiovascular medicine, myocardial ischemia and infarction, progressing eventually to the final end point heart failure (HF), remain the leading cause of morbidity and mortality in the USA. HF is a complex syndrome that results from any structural or functional impairment in ventricular filling or blood ejection. Ultimately, the heart's inability to supply the body's tissues with enough blood may lead to death. Mechanistically, the hallmarks of the failing heart include abnormal energy metabolism, increased production of reactive oxygen species (ROS) and defects in excitation-contraction coupling. HF is a highly dynamic pathological process, and observed alterations in cardiac metabolism and function depend on the disease progression. In the early stages, cardiac remodeling characterized by normal or slightly increased fatty acid (FA) oxidation plays a compensatory, cardioprotective role. However, upon progression of HF, FA oxidation and mitochondrial oxidative activity are decreased, resulting in a significant drop in cardiac ATP levels. In HF, as a compensatory response to decreased oxidative metabolism, glucose uptake and glycolysis are upregulated, but this upregulation is not sufficient to compensate for a drop in ATP production. Elevated mitochondrial ROS generation and ROS-mediated damage, when they overwhelm the cellular antioxidant defense system, induce heart injury and contribute to the progression of HF. Mitochondrial uncoupling proteins (UCPs), which promote proton leak across the inner mitochondrial membrane, have emerged as essential regulators of mitochondrial membrane potential, respiratory activity and ROS generation. Although the physiological role of UCP2 and UCP3, expressed in the heart, has not been clearly established, increasing evidence suggests that these proteins by promoting mild uncoupling could reduce mitochondrial ROS generation and cardiomyocyte apoptosis and ameliorate thereby myocardial function. Further investigation on the alterations in cardiac UCP activity and regulation will advance our understanding of their physiological roles in the healthy and diseased heart and also may facilitate the development of novel and more efficient therapies.
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Affiliation(s)
- Alexander T Akhmedov
- The Molecular Cardiology and Neuromuscular Institute, 75 Raritan Avenue, Highland Park, NJ, 08904, USA
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45
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Fernández-Vizarra E, Zeviani M. Nuclear gene mutations as the cause of mitochondrial complex III deficiency. Front Genet 2015; 6:134. [PMID: 25914718 PMCID: PMC4391031 DOI: 10.3389/fgene.2015.00134] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Accepted: 03/20/2015] [Indexed: 11/13/2022] Open
Abstract
Complex III (CIII) deficiency is one of the least common oxidative phosphorylation defects associated to mitochondrial disease. CIII constitutes the center of the mitochondrial respiratory chain, as well as a crossroad for several other metabolic pathways. For more than 10 years, of all the potential candidate genes encoding structural subunits and assembly factors, only three were known to be associated to CIII defects in human pathology. Thus, leaving many of these cases unresolved. These first identified genes were MT-CYB, the only CIII subunit encoded in the mitochondrial DNA; BCS1L, encoding an assembly factor, and UQCRB, a nuclear-encoded structural subunit. Nowadays, thanks to the fast progress that has taken place in the last 3-4 years, pathological changes in seven more genes are known to be associated to these conditions. This review will focus on the strategies that have permitted the latest discovery of mutations in factors that are necessary for a correct CIII assembly and activity, in relation with their function. In addition, new data further establishing the molecular role of LYRM7/MZM1L as a chaperone involved in CIII biogenesis are provided.
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Affiliation(s)
| | - Massimo Zeviani
- Mitochondrial Biology Unit, Medical Research Council Cambridge, UK
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46
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Mailloux RJ. Teaching the fundamentals of electron transfer reactions in mitochondria and the production and detection of reactive oxygen species. Redox Biol 2015; 4:381-98. [PMID: 25744690 PMCID: PMC4348434 DOI: 10.1016/j.redox.2015.02.001] [Citation(s) in RCA: 184] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Accepted: 02/01/2015] [Indexed: 12/11/2022] Open
Abstract
Mitochondria fulfill a number of biological functions which inherently depend on ATP and O2(-•)/H2O2 production. Both ATP and O2(-•)/H2O2 are generated by electron transfer reactions. ATP is the product of oxidative phosphorylation whereas O2(-•) is generated by singlet electron reduction of di-oxygen (O2). O2(-•) is then rapidly dismutated by superoxide dismutase (SOD) producing H2O2. O2(-•)/H2O2 were once viewed as unfortunately by-products of aerobic respiration. This characterization is fitting considering over production of O2(-•)/H2O2 by mitochondria is associated with range of pathological conditions and aging. However, O2(-•)/H2O2 are only dangerous in large quantities. If produced in a controlled fashion and maintained at a low concentration, cells can benefit greatly from the redox properties of O2(-•)/H2O2. Indeed, low rates of O2(-•)/H2O2 production are required for intrinsic mitochondrial signaling (e.g. modulation of mitochondrial processes) and communication with the rest of the cell. O2(-•)/H2O2 levels are kept in check by anti-oxidant defense systems that sequester O2(-•)/H2O2 with extreme efficiency. Given the importance of O2(-•)/H2O2 in cellular function, it is imperative to consider how mitochondria produce O2(-•)/H2O2 and how O2(-•)/H2O2 genesis is regulated in conjunction with fluctuations in nutritional and redox states. Here, I discuss the fundamentals of electron transfer reactions in mitochondria and emerging knowledge on the 11 potential sources of mitochondrial O2(-•)/H2O2 in tandem with their significance in contributing to overall O2(-•)/H2O2 emission in health and disease. The potential for classifying these different sites in isopotential groups, which is essentially defined by the redox properties of electron donator involved in O2(-•)/H2O2 production, as originally suggested by Brand and colleagues is also surveyed in detail. In addition, redox signaling mechanisms that control O2(-•)/H2O2 genesis from these sites are discussed. Finally, the current methodologies utilized for measuring O2(-•)/H2O2 in isolated mitochondria, cell culture and in vivo are reviewed.
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Affiliation(s)
- Ryan J Mailloux
- Department of Biology, Faculty of Sciences, University of Ottawa, 30 Marie Curie, Ottawa, ON, Canada K1N 6N5.
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Mohapatra PK, Singh NR. Teaching the Z-Scheme of electron transport in photosynthesis: a perspective. PHOTOSYNTHESIS RESEARCH 2015; 123:105-114. [PMID: 25209177 DOI: 10.1007/s11120-014-0034-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Accepted: 08/01/2014] [Indexed: 06/03/2023]
Abstract
This paper deals with how Govindjee taught the Z-Scheme of electron transport in oxygenic photosynthesis at Ravenshaw University, Cuttack, Odisha, India, in 2014, in a unique and highly effective fashion-using students to act as molecules, representing the entire electron transport chain from water to nicotinamide adenine dinucleotide phosphate (NADP(+)). It culminated in a show by B.Sc. students in the garden of the Department of Botany, Ravenshaw University. The first author (PKM) personally acted as Ferredoxin NADP Reductase (FNR) catalyzing the reduction of NADP(+) to NADPH, taking electrons from reduced ferredoxin at the end of Photosystem I. On the other hand, the Q-cycle was played by M.Sc. students, who acted as molecules running this ingenious cycle that produces extra protons. An interesting event was when a student, acting as a herbicide, who was dressed like a devil (fierce looking, in black clothes with a sword; "Yamaraj: The God of Death", as he called himself), stopped all reactions by throwing out QB, the second plastoquinone molecule of Photosystem II, and that too aggressively, taking its position instead. The second author was the major organizer of the Z-scheme show. We provide here a basic background on the process, a bit on Govindjee's teaching, and some selected pictures from the drama played in March, 2014 at Ravenshaw University. Here, we also recognize the teacher Govindjee for his ingenious and fun-filled teaching methods that touched the hearts and the souls of the students as well as the teachers of Ravenshaw University. He was rated as one of the most-admired teachers of plant biology at our university.
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48
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Sarewicz M, Osyczka A. Electronic connection between the quinone and cytochrome C redox pools and its role in regulation of mitochondrial electron transport and redox signaling. Physiol Rev 2015; 95:219-43. [PMID: 25540143 PMCID: PMC4281590 DOI: 10.1152/physrev.00006.2014] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Mitochondrial respiration, an important bioenergetic process, relies on operation of four membranous enzymatic complexes linked functionally by mobile, freely diffusible elements: quinone molecules in the membrane and water-soluble cytochromes c in the intermembrane space. One of the mitochondrial complexes, complex III (cytochrome bc1 or ubiquinol:cytochrome c oxidoreductase), provides an electronic connection between these two diffusible redox pools linking in a fully reversible manner two-electron quinone oxidation/reduction with one-electron cytochrome c reduction/oxidation. Several features of this homodimeric enzyme implicate that in addition to its well-defined function of contributing to generation of proton-motive force, cytochrome bc1 may be a physiologically important point of regulation of electron flow acting as a sensor of the redox state of mitochondria that actively responds to changes in bioenergetic conditions. These features include the following: the opposing redox reactions at quinone catalytic sites located on the opposite sides of the membrane, the inter-monomer electronic connection that functionally links four quinone binding sites of a dimer into an H-shaped electron transfer system, as well as the potential to generate superoxide and release it to the intermembrane space where it can be engaged in redox signaling pathways. Here we highlight recent advances in understanding how cytochrome bc1 may accomplish this regulatory physiological function, what is known and remains unknown about catalytic and side reactions within the quinone binding sites and electron transfers through the cofactor chains connecting those sites with the substrate redox pools. We also discuss the developed molecular mechanisms in the context of physiology of mitochondria.
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Affiliation(s)
- Marcin Sarewicz
- Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Artur Osyczka
- Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Kraków, Poland
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49
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Hong S, de Almeida W, Taguchi AT, Samoilova R, Gennis RB, O’Malley PJ, Dikanov SA, Crofts AR. The semiquinone at the Qi site of the bc1 complex explored using HYSCORE spectroscopy and specific isotopic labeling of ubiquinone in Rhodobacter sphaeroides via (13)C methionine and construction of a methionine auxotroph. Biochemistry 2014; 53:6022-31. [PMID: 25184535 PMCID: PMC4179594 DOI: 10.1021/bi500654y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 09/02/2014] [Indexed: 11/30/2022]
Abstract
Specific isotopic labeling at the residue or substituent level extends the scope of different spectroscopic approaches to the atomistic level. Here we describe (13)C isotopic labeling of the methyl and methoxy ring substituents of ubiquinone, achieved through construction of a methionine auxotroph in Rhodobacter sphaeroides strain BC17 supplemented with l-methionine with the side chain methyl group (13)C-labeled. Two-dimensional electron spin echo envelope modulation (HYSCORE) was applied to study the (13)C methyl and methoxy hyperfine couplings in the semiquinone generated in situ at the Qi site of the bc1 complex in its membrane environment. The data were used to characterize the distribution of unpaired spin density and the conformations of the methoxy substituents based on density functional theory calculations of (13)C hyperfine tensors in the semiquinone of the geometry-optimized X-ray structure of the bc1 complex (Protein Data Bank entry 1PP9 ) with the highest available resolution. Comparison with other proteins indicates individual orientations of the methoxy groups in each particular case are always different from the methoxy conformations in the anion radical prepared in a frozen alcohol solution. The protocol used in the generation of the methionine auxotroph is more generally applicable and, because it introduces a gene deletion using a suicide plasmid, can be applied repeatedly.
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Affiliation(s)
- Sangjin Hong
- Department
of Biochemistry, University of Illinois
at Urbana-Champaign, Urbana, Illinois 61801, United States
| | | | - Alexander T. Taguchi
- Center
for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Rimma
I. Samoilova
- V.
V. Voevodsky Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, Novosibirsk 630090, Russian Federation
| | - Robert B. Gennis
- Department
of Biochemistry, University of Illinois
at Urbana-Champaign, Urbana, Illinois 61801, United States
| | | | - Sergei A. Dikanov
- Department
of Veterinary Clinical Medicine, University
of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Antony R. Crofts
- Department
of Biochemistry, University of Illinois
at Urbana-Champaign, Urbana, Illinois 61801, United States
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50
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Hasan SS, Zakharov SD, Chauvet A, Stadnytskyi V, Savikhin S, Cramer WA. A map of dielectric heterogeneity in a membrane protein: the hetero-oligomeric cytochrome b6f complex. J Phys Chem B 2014; 118:6614-25. [PMID: 24867491 PMCID: PMC4067154 DOI: 10.1021/jp501165k] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
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The
cytochrome b6f complex,
a member of the cytochrome bc family that
mediates energy transduction in photosynthetic and respiratory membranes,
is a hetero-oligomeric complex that utilizes two pairs of b-hemes in a symmetric dimer to accomplish trans-membrane
electron transfer, quinone oxidation–reduction, and generation
of a proton electrochemical potential. Analysis of electron storage
in this pathway, utilizing simultaneous measurement of heme reduction,
and of circular dichroism (CD) spectra, to assay heme–heme
interactions, implies a heterogeneous distribution of the dielectric
constants that mediate electrostatic interactions between the four
hemes in the complex. Crystallographic information was used to determine
the identity of the interacting hemes. The Soret band CD signal is
dominated by excitonic interaction between the intramonomer b-hemes, bn and bp, on the electrochemically negative and positive sides
of the complex. Kinetic data imply that the most probable pathway
for transfer of the two electrons needed for quinone oxidation–reduction
utilizes this intramonomer heme pair, contradicting the expectation
based on heme redox potentials and thermodynamics, that the two higher
potential hemes bn on different monomers
would be preferentially reduced. Energetically preferred intramonomer
electron storage of electrons on the intramonomer b-hemes is found to require heterogeneity of interheme dielectric
constants. Relative to the medium separating the two higher potential
hemes bn, a relatively large dielectric
constant must exist between the intramonomer b-hemes,
allowing a smaller electrostatic repulsion between the reduced hemes.
Heterogeneity of dielectric constants is an additional structure–function
parameter of membrane protein complexes.
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Affiliation(s)
- S Saif Hasan
- Department of Biological Sciences and ‡Department of Physics, Purdue University , West Lafayette, Indiana 47907, United States
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