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Huang D, Jing G, Zhu S. Regulation of Mitochondrial Respiration by Hydrogen Sulfide. Antioxidants (Basel) 2023; 12:1644. [PMID: 37627639 PMCID: PMC10451548 DOI: 10.3390/antiox12081644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/10/2023] [Accepted: 08/14/2023] [Indexed: 08/27/2023] Open
Abstract
Hydrogen sulfide (H2S), the third gasotransmitter, has positive roles in animals and plants. Mitochondria are the source and the target of H2S and the regulatory hub in metabolism, stress, and disease. Mitochondrial bioenergetics is a vital process that produces ATP and provides energy to support the physiological and biochemical processes. H2S regulates mitochondrial bioenergetic functions and mitochondrial oxidative phosphorylation. The article summarizes the recent knowledge of the chemical and biological characteristics, the mitochondrial biosynthesis of H2S, and the regulatory effects of H2S on the tricarboxylic acid cycle and the mitochondrial respiratory chain complexes. The roles of H2S on the tricarboxylic acid cycle and mitochondrial respiratory complexes in mammals have been widely studied. The biological function of H2S is now a hot topic in plants. Mitochondria are also vital organelles regulating plant processes. The regulation of H2S in plant mitochondrial functions is gaining more and more attention. This paper mainly summarizes the current knowledge on the regulatory effects of H2S on the tricarboxylic acid cycle (TCA) and the mitochondrial respiratory chain. A study of the roles of H2S in mitochondrial respiration in plants to elucidate the botanical function of H2S in plants would be highly desirable.
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Affiliation(s)
| | | | - Shuhua Zhu
- College of Chemistry and Material Science, Shandong Agricultural University, Taian 271018, China; (D.H.); (G.J.)
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2
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van Strien J, Evers F, Lutikurti M, Berendsen SL, Garanto A, van Gemert GJ, Cabrera-Orefice A, Rodenburg RJ, Brandt U, Kooij TWA, Huynen MA. Comparative Clustering (CompaCt) of eukaryote complexomes identifies novel interactions and sheds light on protein complex evolution. PLoS Comput Biol 2023; 19:e1011090. [PMID: 37549177 PMCID: PMC10434966 DOI: 10.1371/journal.pcbi.1011090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 08/17/2023] [Accepted: 07/10/2023] [Indexed: 08/09/2023] Open
Abstract
Complexome profiling allows large-scale, untargeted, and comprehensive characterization of protein complexes in a biological sample using a combined approach of separating intact protein complexes e.g., by native gel electrophoresis, followed by mass spectrometric analysis of the proteins in the resulting fractions. Over the last decade, its application has resulted in a large collection of complexome profiling datasets. While computational methods have been developed for the analysis of individual datasets, methods for large-scale comparative analysis of complexomes from multiple species are lacking. Here, we present Comparative Clustering (CompaCt), that performs fully automated integrative analysis of complexome profiling data from multiple species, enabling systematic characterization and comparison of complexomes. CompaCt implements a novel method for leveraging orthology in comparative analysis to allow systematic identification of conserved as well as taxon-specific elements of the analyzed complexomes. We applied this method to a collection of 53 complexome profiles spanning the major branches of the eukaryotes. We demonstrate the ability of CompaCt to robustly identify the composition of protein complexes, and show that integrated analysis of multiple datasets improves characterization of complexes from specific complexome profiles when compared to separate analyses. We identified novel candidate interactors and complexes in a number of species from previously analyzed datasets, like the emp24, the V-ATPase and mitochondrial ATP synthase complexes. Lastly, we demonstrate the utility of CompaCt for the automated large-scale characterization of the complexome of the mosquito Anopheles stephensi shedding light on the evolution of metazoan protein complexes. CompaCt is available from https://github.com/cmbi/compact-bio.
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Affiliation(s)
- Joeri van Strien
- Department of Medical BioSciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Felix Evers
- Medical Microbiology, Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Madhurya Lutikurti
- Department of Pediatrics, Amalia Children’s Hospital, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Stijn L. Berendsen
- Department of Pediatrics, Amalia Children’s Hospital, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Alejandro Garanto
- Department of Pediatrics, Amalia Children’s Hospital, Radboud University Medical Center, Nijmegen, the Netherlands
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Radboud Center for Mitochondrial Medicine (RCMM), Radboud University Medical Center, Nijmegen, the Netherlands
| | - Geert-Jan van Gemert
- Medical Microbiology, Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Alfredo Cabrera-Orefice
- Department of Medical BioSciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Richard J. Rodenburg
- Radboud Center for Mitochondrial Medicine (RCMM), Radboud University Medical Center, Nijmegen, the Netherlands
- Department of Pediatrics, Translational Metabolic Laboratory, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Ulrich Brandt
- Department of Pediatrics, Amalia Children’s Hospital, Radboud University Medical Center, Nijmegen, the Netherlands
- Radboud Center for Mitochondrial Medicine (RCMM), Radboud University Medical Center, Nijmegen, the Netherlands
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Taco W. A. Kooij
- Medical Microbiology, Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Martijn A. Huynen
- Department of Medical BioSciences, Radboud University Medical Center, Nijmegen, the Netherlands
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3
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Kühlbrandt W. Forty years in cryoEM of membrane proteins. Microscopy (Oxf) 2022; 71:i30-i50. [PMID: 35275191 PMCID: PMC8855526 DOI: 10.1093/jmicro/dfab041] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 10/05/2021] [Accepted: 11/10/2021] [Indexed: 12/13/2022] Open
Abstract
In a surprisingly short time, electron cryo-microscopy (cryoEM) has developed from a niche technique in structural biology to a mainstream method practiced in a rapidly growing number of laboratories around the world. From its beginnings about 40 years ago, cryoEM has had a major impact on the study of membrane proteins, in particular the energy-converting systems from bacterial, mitochondrial and chloroplast membranes. Early work on two-dimensional crystals attained resolutions ∼3.5 Å, but at present, single-particle cryoEM delivers much more detailed structures without crystals. Electron cryo-tomography of membranes and membrane-associated proteins adds valuable context, usually at lower resolution. The review ends with a brief outlook on future prospects.
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Affiliation(s)
- Werner Kühlbrandt
- Department of Structural Biology, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, Frankfurt am Main 60438, Germany
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4
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Bibli SI, Fleming I. Oxidative Post-Translational Modifications: A Focus on Cysteine S-Sulfhydration and the Regulation of Endothelial Fitness. Antioxid Redox Signal 2021; 35:1494-1514. [PMID: 34346251 DOI: 10.1089/ars.2021.0162] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Significance: Changes in the oxidative balance can affect cellular physiology and adaptation through redox signaling. The endothelial cells that line blood vessels are particularly sensitive to reactive oxygen species, which can alter cell function by a number of mechanisms, including the oxidative post-translational modification (oxPTM) of proteins on critical cysteine thiols. Such modifications can act as redox-switches to alter the function of targeted proteins. Recent Advances: Mapping the cysteine oxPTM proteome and characterizing the effects of individual oxPTMs to gain insight into consequences for cellular responses has proven challenging. A recent addition to the list of reversible oxPTMs that contributes to cellular redox homeostasis is persulfidation or S-sulfhydration. Critical Issues: It has been estimated that up to 25% of proteins are S-sulfhydrated, making this modification almost as abundant as phosphorylation. In the endothelium, persulfides are generated by the trans-sulfuration pathway that catabolizes cysteine and cystathionine to generate hydrogen sulfide (H2S) and H2S-related sulfane sulfur compounds (H2Sn). This pathway is of particular importance for the vascular system, as the enzyme cystathionine γ lyase (CSE) in endothelial cells accounts for a significant portion of total vascular H2S/H2Sn production. Future Directions: Impaired CSE activity in endothelial dysfunction has been linked with marked changes in the endothelial cell S-sulfhydrome and can contribute to the development of atherosclerosis and hypertension. It will be interesting to determine how changes in the S-sulfhydration of specific networks of proteins contribute to endothelial cell physiology and pathophysiology. Antioxid. Redox Signal. 35, 1494-1514.
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Affiliation(s)
- Sofia-Iris Bibli
- Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University, Frankfurt am Main, Germany.,German Center of Cardiovascular Research (DZHK), Partner Site RheinMain, Frankfurt am Main, Germany
| | - Ingrid Fleming
- Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University, Frankfurt am Main, Germany.,German Center of Cardiovascular Research (DZHK), Partner Site RheinMain, Frankfurt am Main, Germany
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5
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Olson KR. A Case for Hydrogen Sulfide Metabolism as an Oxygen Sensing Mechanism. Antioxidants (Basel) 2021; 10:antiox10111650. [PMID: 34829521 PMCID: PMC8615108 DOI: 10.3390/antiox10111650] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 10/08/2021] [Accepted: 10/13/2021] [Indexed: 12/30/2022] Open
Abstract
The ability to detect oxygen availability is a ubiquitous attribute of aerobic organisms. However, the mechanism(s) that transduce oxygen concentration or availability into appropriate physiological responses is less clear and often controversial. This review will make the case for oxygen-dependent metabolism of hydrogen sulfide (H2S) and polysulfides, collectively referred to as reactive sulfur species (RSS) as a physiologically relevant O2 sensing mechanism. This hypothesis is based on observations that H2S and RSS metabolism is inversely correlated with O2 tension, exogenous H2S elicits physiological responses identical to those produced by hypoxia, factors that affect H2S production or catabolism also affect tissue responses to hypoxia, and that RSS efficiently regulate downstream effectors of the hypoxic response in a manner consistent with a decrease in O2. H2S-mediated O2 sensing is then compared to the more generally accepted reactive oxygen species (ROS) mediated O2 sensing mechanism and a number of reasons are offered to resolve some of the confusion between the two.
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Affiliation(s)
- Kenneth R Olson
- Department of Physiology, Indiana University School of Medicine-South Bend, South Bend, IN 46617, USA
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6
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Huang D, Jing G, Zhang L, Chen C, Zhu S. Interplay Among Hydrogen Sulfide, Nitric Oxide, Reactive Oxygen Species, and Mitochondrial DNA Oxidative Damage. FRONTIERS IN PLANT SCIENCE 2021; 12:701681. [PMID: 34421950 PMCID: PMC8377586 DOI: 10.3389/fpls.2021.701681] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 07/06/2021] [Indexed: 06/01/2023]
Abstract
Hydrogen sulfide (H2S), nitric oxide (NO), and reactive oxygen species (ROS) play essential signaling roles in cells by oxidative post-translational modification within suitable ranges of concentration. All of them contribute to the balance of redox and are involved in the DNA damage and repair pathways. However, the damage and repair pathways of mitochondrial DNA (mtDNA) are complicated, and the interactions among NO, H2S, ROS, and mtDNA damage are also intricate. This article summarized the current knowledge about the metabolism of H2S, NO, and ROS and their roles in maintaining redox balance and regulating the repair pathway of mtDNA damage in plants. The three reactive species may likely influence each other in their generation, elimination, and signaling actions, indicating a crosstalk relationship between them. In addition, NO and H2S are reported to be involved in epigenetic variations by participating in various cell metabolisms, including (nuclear and mitochondrial) DNA damage and repair. Nevertheless, the research on the details of NO and H2S in regulating DNA damage repair of plants is in its infancy, especially in mtDNA.
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Affiliation(s)
- Dandan Huang
- Food Safety Analysis and Test Engineering Technology Research Center of Shandong Province, College of Chemistry and Material Science, Shandong Agricultural University, Tai’an, China
| | - Guangqin Jing
- Food Safety Analysis and Test Engineering Technology Research Center of Shandong Province, College of Chemistry and Material Science, Shandong Agricultural University, Tai’an, China
- College of Life Sciences, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China
| | - Lili Zhang
- Food Safety Analysis and Test Engineering Technology Research Center of Shandong Province, College of Chemistry and Material Science, Shandong Agricultural University, Tai’an, China
| | - Changbao Chen
- Food Safety Analysis and Test Engineering Technology Research Center of Shandong Province, College of Chemistry and Material Science, Shandong Agricultural University, Tai’an, China
| | - Shuhua Zhu
- Food Safety Analysis and Test Engineering Technology Research Center of Shandong Province, College of Chemistry and Material Science, Shandong Agricultural University, Tai’an, China
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7
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Klusch N, Senkler J, Yildiz Ö, Kühlbrandt W, Braun HP. A ferredoxin bridge connects the two arms of plant mitochondrial complex I. THE PLANT CELL 2021; 33:2072-2091. [PMID: 33768254 PMCID: PMC8290278 DOI: 10.1093/plcell/koab092] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 03/19/2021] [Indexed: 05/23/2023]
Abstract
Mitochondrial complex I is the main site for electron transfer to the respiratory chain and generates much of the proton gradient across the inner mitochondrial membrane. Complex I is composed of two arms, which form a conserved L-shape. We report the structures of the intact, 47-subunit mitochondrial complex I from Arabidopsis thaliana and the 51-subunit complex I from the green alga Polytomella sp., both at around 2.9 Å resolution. In both complexes, a heterotrimeric γ-carbonic anhydrase domain is attached to the membrane arm on the matrix side. Two states are resolved in A. thaliana complex I, with different angles between the two arms and different conformations of the ND1 (NADH dehydrogenase subunit 1) loop near the quinol binding site. The angle appears to depend on a bridge domain, which links the peripheral arm to the membrane arm and includes an unusual ferredoxin. We propose that the bridge domain participates in regulating the activity of plant complex I.
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Affiliation(s)
- Niklas Klusch
- Department of Structural Biology, Max-Planck-Institute of Biophysics, Frankfurt 60438, Germany
| | - Jennifer Senkler
- Institut für Pflanzengenetik, Leibniz Universität Hannover, Hannover 30419, Germany
| | - Özkan Yildiz
- Department of Structural Biology, Max-Planck-Institute of Biophysics, Frankfurt 60438, Germany
| | - Werner Kühlbrandt
- Department of Structural Biology, Max-Planck-Institute of Biophysics, Frankfurt 60438, Germany
| | - Hans-Peter Braun
- Institut für Pflanzengenetik, Leibniz Universität Hannover, Hannover 30419, Germany
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8
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Kell DB. A protet-based, protonic charge transfer model of energy coupling in oxidative and photosynthetic phosphorylation. Adv Microb Physiol 2021; 78:1-177. [PMID: 34147184 DOI: 10.1016/bs.ampbs.2021.01.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Textbooks of biochemistry will explain that the otherwise endergonic reactions of ATP synthesis can be driven by the exergonic reactions of respiratory electron transport, and that these two half-reactions are catalyzed by protein complexes embedded in the same, closed membrane. These views are correct. The textbooks also state that, according to the chemiosmotic coupling hypothesis, a (or the) kinetically and thermodynamically competent intermediate linking the two half-reactions is the electrochemical difference of protons that is in equilibrium with that between the two bulk phases that the coupling membrane serves to separate. This gradient consists of a membrane potential term Δψ and a pH gradient term ΔpH, and is known colloquially as the protonmotive force or pmf. Artificial imposition of a pmf can drive phosphorylation, but only if the pmf exceeds some 150-170mV; to achieve in vivo rates the imposed pmf must reach 200mV. The key question then is 'does the pmf generated by electron transport exceed 200mV, or even 170mV?' The possibly surprising answer, from a great many kinds of experiment and sources of evidence, including direct measurements with microelectrodes, indicates it that it does not. Observable pH changes driven by electron transport are real, and they control various processes; however, compensating ion movements restrict the Δψ component to low values. A protet-based model, that I outline here, can account for all the necessary observations, including all of those inconsistent with chemiosmotic coupling, and provides for a variety of testable hypotheses by which it might be refined.
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Affiliation(s)
- Douglas B Kell
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative, Biology, University of Liverpool, Liverpool, United Kingdom; The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark.
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9
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A conserved arginine residue is critical for stabilizing the N2 FeS cluster in mitochondrial complex I. J Biol Chem 2021; 296:100474. [PMID: 33640456 PMCID: PMC8042128 DOI: 10.1016/j.jbc.2021.100474] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 02/18/2021] [Accepted: 02/24/2021] [Indexed: 11/22/2022] Open
Abstract
Respiratory complex I (NADH:ubiquinone oxidoreductase), the first enzyme of the electron-transport chain, captures the free energy released by NADH oxidation and ubiquinone reduction to translocate protons across an energy-transducing membrane and drive ATP synthesis during oxidative phosphorylation. The cofactor that transfers the electrons directly to ubiquinone is an iron–sulfur cluster (N2) located in the NDUFS2/NUCM subunit. A nearby arginine residue (R121), which forms part of the second coordination sphere of the N2 cluster, is known to be posttranslationally dimethylated but its functional and structural significance are not known. Here, we show that mutations of this arginine residue (R121M/K) abolish the quinone-reductase activity, concomitant with disappearance of the N2 signature from the electron paramagnetic resonance (EPR) spectrum. Analysis of the cryo-EM structure of NDUFS2-R121M complex I at 3.7 Å resolution identified the absence of the cubane N2 cluster as the cause of the dysfunction, within an otherwise intact enzyme. The mutation further induced localized disorder in nearby elements of the quinone-binding site, consistent with the close connections between the cluster and substrate-binding regions. Our results demonstrate that R121 is required for the formation and/or stability of the N2 cluster and highlight the importance of structural analyses for mechanistic interpretation of biochemical and spectroscopic data on complex I variants.
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10
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Abstract
Significance: Oxidative stress in moderation positively affects homeostasis through signaling, while in excess it is associated with adverse health outcomes. Both activities are generally attributed to reactive oxygen species (ROS); hydrogen peroxide as the signal, and cysteines on regulatory proteins as the target. However, using antioxidants to affect signaling or benefit health has not consistently translated into expected outcomes, or when it does, the mechanism is often unclear. Recent Advances: Reactive sulfur species (RSS) were integral in the origin of life and throughout much of evolution. Sophisticated metabolic pathways that evolved to regulate RSS were easily "tweaked" to deal with ROS due to the remarkable similarities between the two. However, unlike ROS, RSS are stored, recycled, and chemically more versatile. Despite these observations, the relevance and regulatory functions of RSS in extant organisms are generally underappreciated. Critical Issues: A number of factors bias observations in favor of ROS over RSS. Research conducted in room air is hyperoxic to cells, and promotes ROS production and RSS oxidation. Metabolic rates of rodent models greatly exceed those of humans; does this favor ROS? Analytical methods designed to detect ROS also respond to RSS. Do these disguise the contributions of RSS? Future Directions: Resolving the ROS/RSS issue is vital to understand biology in general and human health in particular. Improvements in experimental design and analytical methods are crucial. Perhaps the most important is an appreciation of all the attributes of RSS and keeping an open mind.
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Affiliation(s)
- Kenneth R Olson
- Department of Physiology, Indiana University School of Medicine-South Bend, South Bend, Indiana, USA
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11
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Grba DN, Hirst J. Mitochondrial complex I structure reveals ordered water molecules for catalysis and proton translocation. Nat Struct Mol Biol 2020; 27:892-900. [PMID: 32747785 PMCID: PMC7612091 DOI: 10.1038/s41594-020-0473-x] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 06/26/2020] [Indexed: 01/09/2023]
Abstract
Mitochondrial complex I powers ATP synthesis by oxidative phosphorylation, exploiting the energy from ubiquinone reduction by NADH to drive protons across the energy-transducing inner membrane. Recent cryo-EM analyses of mammalian and yeast complex I have revolutionized structural and mechanistic knowledge and defined structures in different functional states. Here, we describe a 2.7-Å-resolution structure of the 42-subunit complex I from the yeast Yarrowia lipolytica containing 275 structured water molecules. We identify a proton-relay pathway for ubiquinone reduction and water molecules that connect mechanistically crucial elements and constitute proton-translocation pathways through the membrane. By comparison with known structures, we deconvolute structural changes governing the mammalian 'deactive transition' (relevant to ischemia-reperfusion injury) and their effects on the ubiquinone-binding site and a connected cavity in ND1. Our structure thus provides important insights into catalysis by this enigmatic respiratory machine.
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Affiliation(s)
- Daniel N Grba
- The Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Judy Hirst
- The Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK.
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12
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Respiratory complex I - Mechanistic insights and advances in structure determination. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148153. [PMID: 31935361 DOI: 10.1016/j.bbabio.2020.148153] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 12/16/2019] [Accepted: 01/08/2020] [Indexed: 12/17/2022]
Abstract
Complex I is the largest and most intricate redox-driven proton pump of the respiratory chain. The structure of bacterial and mitochondrial complex I has been determined by X-ray crystallography and cryo-EM at increasing resolution. The recent cryo-EM structures of the complex I-like NDH complex and membrane bound hydrogenase open a new and more comprehensive perspective on the complex I superfamily. Functional studies and molecular modeling approaches have greatly advanced our understanding of the catalytic cycle of complex I. However, the molecular mechanism by which energy is extracted from the redox reaction and utilized to drive proton translocation is unresolved and a matter of ongoing debate. Here, we review progress in structure determination and functional characterization of complex I and discuss current mechanistic models.
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13
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Olson KR. Hydrogen sulfide, reactive sulfur species and coping with reactive oxygen species. Free Radic Biol Med 2019; 140:74-83. [PMID: 30703482 DOI: 10.1016/j.freeradbiomed.2019.01.020] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 12/19/2018] [Accepted: 01/18/2019] [Indexed: 12/31/2022]
Abstract
Life began in a ferruginous (anoxic and Fe2+ dominated) world around 3.8 billion years ago (bya). Hydrogen sulfide (H2S) and other sulfur molecules from hydrothermal vents and other fissures provided many key necessities for life's origin including catalytic platforms (primordial enzymes) that also served as primitive boundaries (cell walls), substrates for organic synthesis and a continuous source of energy in the form of reducing equivalents. Anoxigenic photosynthesis oxidizing H2S followed within a few hundred million years and laid the metabolic groundwork for oxidative photosynthesis some half-billion years later that slightly and episodically increased atmospheric oxygen around 2.3 bya. This oxidized terrestrial sulfur to sulfate which was washed to the sea where it was reduced creating vast euxinic (anoxic and sulfidic) areas. It was in this environment that eukaryotic cells appeared around 1.5 bya and where they evolved for nearly 1 billion additional years. Oxidative photosynthesis finally oxidized the oceans and around 0.6 bya oxygen levels in the atmosphere and oceans began to rise toward present day levels. This is purported to have been a life-threatening event due to the prevalence of reactive oxygen species (ROS) and thus necessitated the elaboration of chemical and enzymatic antioxidant mechanisms. However, these antioxidants initially appeared around the time of anoxigenic photosynthesis suggesting a commitment to metabolism of reactive sulfur species (RSS). This review examines these events and suggests that many of the biological attributes assigned to ROS may, in fact, be due to RSS. This is underscored by observations that ROS and RSS are chemically similar, often indistinguishable by analytical methods and the fact that the bulk of biochemical and physiological experiments are performed in unphysiologically oxic environments where ROS are artifactually favored over RSS.
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Affiliation(s)
- Kenneth R Olson
- Indiana University School of Medicine-South Bend, Raclin Carmichael Hall, 1234 Notre Dame Ave, South Bend, IN 46617, USA.
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14
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Scherr J, Neuhaus A, Parey K, Klusch N, Murphy BJ, Zickermann V, Kühlbrandt W, Terfort A, Rhinow D. Noncovalent Functionalization of Carbon Substrates with Hydrogels Improves Structural Analysis of Vitrified Proteins by Electron Cryo-Microscopy. ACS NANO 2019; 13:7185-7190. [PMID: 31117383 DOI: 10.1021/acsnano.9b02651] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In electron cryo-microscopy, structure determination of protein molecules is frequently hampered by adsorption of the particles to the support film material, typically amorphous carbon. Here, we report that pyrene derivatives with one or two polyglycerol (PG) side chains bind to the amorphous carbon films, forming a biorepulsive hydrogel layer so that the number of protein particles in the vitreous ice drastically increases. This approach could be extended by adding a hydrogel-functionalized carbon nanotube network (HyCaNet, the hydrogel again being formed from the PG-pyrene derivatives), which stabilized the protein-containing thin ice films during imaging with the electron beam. The stabilization resulted in reduced particle motion by up to 70%. These substrates were instrumental for determining the structure of a large membrane protein complex.
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Affiliation(s)
- Julian Scherr
- Department of Chemistry, Institute of Inorganic and Analytical Chemistry , Goethe-University Frankfurt , Max-von-Laue-Str. 7 , 60438 Frankfurt , Germany
| | - Alexander Neuhaus
- Department of Structural Biology , Max Planck Institute of Biophysics , Max-von-Laue-Str. 3 , 60438 Frankfurt , Germany
| | - Kristian Parey
- Department of Structural Biology , Max Planck Institute of Biophysics , Max-von-Laue-Str. 3 , 60438 Frankfurt , Germany
| | - Niklas Klusch
- Department of Structural Biology , Max Planck Institute of Biophysics , Max-von-Laue-Str. 3 , 60438 Frankfurt , Germany
| | - Bonnie J Murphy
- Department of Structural Biology , Max Planck Institute of Biophysics , Max-von-Laue-Str. 3 , 60438 Frankfurt , Germany
| | - Volker Zickermann
- Structural Bioenergetics Group , Institute of Biochemistry II, Medical School , Max-von-Laue-Str. 9 , 60438 Frankfurt , Germany
| | - Werner Kühlbrandt
- Department of Structural Biology , Max Planck Institute of Biophysics , Max-von-Laue-Str. 3 , 60438 Frankfurt , Germany
| | - Andreas Terfort
- Department of Chemistry, Institute of Inorganic and Analytical Chemistry , Goethe-University Frankfurt , Max-von-Laue-Str. 7 , 60438 Frankfurt , Germany
| | - Daniel Rhinow
- Department of Structural Biology , Max Planck Institute of Biophysics , Max-von-Laue-Str. 3 , 60438 Frankfurt , Germany
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15
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Meyer EH, Welchen E, Carrie C. Assembly of the Complexes of the Oxidative Phosphorylation System in Land Plant Mitochondria. ANNUAL REVIEW OF PLANT BIOLOGY 2019; 70:23-50. [PMID: 30822116 DOI: 10.1146/annurev-arplant-050718-100412] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Plant mitochondria play a major role during respiration by producing the ATP required for metabolism and growth. ATP is produced during oxidative phosphorylation (OXPHOS), a metabolic pathway coupling electron transfer with ADP phosphorylation via the formation and release of a proton gradient across the inner mitochondrial membrane. The OXPHOS system is composed of large, multiprotein complexes coordinating metal-containing cofactors for the transfer of electrons. In this review, we summarize the current state of knowledge about assembly of the OXPHOS complexes in land plants. We present the different steps involved in the formation of functional complexes and the regulatory mechanisms controlling the assembly pathways. Because several assembly steps have been found to be ancestral in plants-compared with those described in fungal and animal models-we discuss the evolutionary dynamics that lead to the conservation of ancestral pathways in land plant mitochondria.
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Affiliation(s)
- Etienne H Meyer
- Organelle Biology and Biotechnology Research Group, Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
- Current affiliation: Institute of Plant Physiology, Martin-Luther-University Halle-Wittenberg, 06120 Halle, Germany;
| | - Elina Welchen
- Cátedra de Biología Celular y Molecular, Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, 3000 Santa Fe, Argentina
| | - Chris Carrie
- Plant Sciences Research Group, Department Biologie I, Ludwig-Maximilians-Universität, 82152 Planegg-Martinsried, Germany
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Parey K, Brandt U, Xie H, Mills DJ, Siegmund K, Vonck J, Kühlbrandt W, Zickermann V. Cryo-EM structure of respiratory complex I at work. eLife 2018; 7:39213. [PMID: 30277212 PMCID: PMC6168287 DOI: 10.7554/elife.39213] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 08/30/2018] [Indexed: 01/08/2023] Open
Abstract
Mitochondrial complex I has a key role in cellular energy metabolism, generating a major portion of the proton motive force that drives aerobic ATP synthesis. The hydrophilic arm of the L-shaped ~1 MDa membrane protein complex transfers electrons from NADH to ubiquinone, providing the energy to drive proton pumping at distant sites in the membrane arm. The critical steps of energy conversion are associated with the redox chemistry of ubiquinone. We report the cryo-EM structure of complete mitochondrial complex I from the aerobic yeast Yarrowia lipolytica both in the deactive form and after capturing the enzyme during steady-state activity. The site of ubiquinone binding observed during turnover supports a two-state stabilization change mechanism for complex I.
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Affiliation(s)
- Kristian Parey
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Ulrich Brandt
- Radboud Institute for Molecular Life Sciences, Department of Pediatrics, Radboud University Medical Centre, Nijmegen, The Netherlands.,Cluster of Excellence Macromolecular Complexes, Goethe University Frankfurt, Frankfurt, Germany
| | - Hao Xie
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Deryck J Mills
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Karin Siegmund
- Medical School, Institute of Biochemistry II, Goethe University Frankfurt, Frankfurt, Germany.,Centre for Biomolecular Magnetic Resonance, Institute for Biophysical Chemistry, Goethe University Frankfurt, Frankfurt, Germany
| | - Janet Vonck
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Werner Kühlbrandt
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt, Germany.,Cluster of Excellence Macromolecular Complexes, Goethe University Frankfurt, Frankfurt, Germany
| | - Volker Zickermann
- Cluster of Excellence Macromolecular Complexes, Goethe University Frankfurt, Frankfurt, Germany.,Medical School, Institute of Biochemistry II, Goethe University Frankfurt, Frankfurt, Germany.,Centre for Biomolecular Magnetic Resonance, Institute for Biophysical Chemistry, Goethe University Frankfurt, Frankfurt, Germany
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Spectral comparisons of mammalian cells and intact organelles by solid-state NMR. J Struct Biol 2018; 206:49-54. [PMID: 29859329 DOI: 10.1016/j.jsb.2018.05.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 03/15/2018] [Accepted: 05/25/2018] [Indexed: 01/18/2023]
Abstract
Whole-cell protein profiling, spatial localization, and quantification of activities such as gene transcription and protein translation are possible with modern biochemical and biophysical techniques. Yet, addressing questions of overall compositional changes within a cell - capturing the relative amounts of protein and ribosomal RNA levels and lipid content simultaneously - would require extractions and purifications with caveats due to isolation yields and detection methods. A holistic view of cellular composition would aid in the study of cellular composition and function. Here, solid state NMR is used to identify 13C NMR signatures for cellular organelles in HeLa cells without the use of any isotopic labeling. Comparisons are made with carbon spectra of subcellular assemblies including DNA, lipids, ribosomes, nuclei and mitochondria. Whole-cell comparisons are made with different mammalian cells lines, with red blood cells that lack nuclei and organelles, and with Gram-negative and Gram-positive bacteria. Furthermore, treatment of mammalian cells with cycloheximide, a commonly used protein synthesis inhibitor, revealed unanticipated changes consistent with a significant increase in protein glycosylation, obvious at the whole cell level. Thus, we demonstrate that solid-state NMR serves as a unique analytical tool to catalog and compare the ratios of distinct carbon types in cells and serves as a discovery tool to reveal the workings of inhibitors such as cycloheximide on whole-cell biochemistry.
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Shimada S, Maeda S, Hikita M, Mieda-Higa K, Uene S, Nariai Y, Shinzawa-Itoh K. Solubilization conditions for bovine heart mitochondrial membranes allow selective purification of large quantities of respiratory complexes I, III, and V. Protein Expr Purif 2018; 150:33-43. [PMID: 29702187 DOI: 10.1016/j.pep.2018.04.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 04/20/2018] [Accepted: 04/23/2018] [Indexed: 11/28/2022]
Abstract
Ascertaining the structure and functions of mitochondrial respiratory chain complexes is essential to understanding the biological mechanisms of energy conversion; therefore, numerous studies have examined these complexes. A fundamental part of that research involves devising a method for purifying samples with good reproducibility; the samples obtained need to be stable and their constituents need to retain the same structure and functions they possess when in mitochondrial membranes. Submitochondrial bovine heart particles were isolated using differential centrifugation to adjust to a membrane concentration of 46.0% (w/v) or 31.5% (w/v) based on weight. After 0.7% (w/v) deoxycholic acid, 0.4% (w/v) decyl maltoside, and 7.2% (w/v) potassium chloride were added to the mitochondrial membranes, those membranes were solubilized. At a membrane concentration of 46%, complex V was selectively solubilized, whereas at a concentration of 31.5% (w/v), complexes I and III were solubilized. Two steps-sucrose density gradient centrifugation and anion-exchange chromatography on a POROS HQ 20 μm column-enabled selective purification of samples that retained their structure and functions. These two steps enabled complexes I, III, and V to be purified in two days with a high yield. Complexes I, III, and V were stabilized with n-decyl-β-D-maltoside. A total of 200 mg-300 mg of those complexes from one bovine heart (1.1 kg muscle) was purified with good reproducibility, and the complexes retained the same functions they possessed while in mitochondrial membranes.
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Affiliation(s)
- Satoru Shimada
- Department of Life Science, Graduate School of Life Science, University of Hyogo, Koto 3-2-1, Kamighori, Ako, Hyogo, 678-1297, Japan
| | - Shintaro Maeda
- Department of Life Science, Graduate School of Life Science, University of Hyogo, Koto 3-2-1, Kamighori, Ako, Hyogo, 678-1297, Japan
| | - Masahide Hikita
- Department of Life Science, Graduate School of Life Science, University of Hyogo, Koto 3-2-1, Kamighori, Ako, Hyogo, 678-1297, Japan
| | - Kaoru Mieda-Higa
- Department of Life Science, Graduate School of Life Science, University of Hyogo, Koto 3-2-1, Kamighori, Ako, Hyogo, 678-1297, Japan
| | - Shigefumi Uene
- Department of Life Science, Graduate School of Life Science, University of Hyogo, Koto 3-2-1, Kamighori, Ako, Hyogo, 678-1297, Japan
| | - Yukiko Nariai
- Department of Life Science, Graduate School of Life Science, University of Hyogo, Koto 3-2-1, Kamighori, Ako, Hyogo, 678-1297, Japan
| | - Kyoko Shinzawa-Itoh
- Department of Life Science, Graduate School of Life Science, University of Hyogo, Koto 3-2-1, Kamighori, Ako, Hyogo, 678-1297, Japan.
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Cossio P, Hummer G. Likelihood-based structural analysis of electron microscopy images. Curr Opin Struct Biol 2018; 49:162-168. [PMID: 29579548 DOI: 10.1016/j.sbi.2018.03.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 01/24/2018] [Accepted: 03/06/2018] [Indexed: 10/17/2022]
Abstract
Likelihood-based analysis of single-particle electron microscopy images has contributed much to the recent improvements in resolution. By treating particle orientations and classes probabilistically, uncertainties in the reconstruction process are explicitly accounted for, and the risk of bias towards the initial model is diminished. As a result, the quality and reliability of the reconstructions have greatly improved at manageable computational cost. Likelihood-based analysis of electron microscopy images also offers a route to direct coordinate refinement for dynamic systems, as an alternative to 3D density reconstruction. Here, we review recent developments in the algorithms used for reconstructions of high-resolution maps, and in the integrative framework of combining likelihood methods with simulations to address conformational variability in cryo-electron microscopy.
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Affiliation(s)
- Pilar Cossio
- Biophysics of Tropical Diseases, Max Planck Tandem Group, University of Antioquia, Medellín, Colombia; Department of Theoretical Biophysics, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany.
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany; Institute of Biophysics, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
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Conserved in situ arrangement of complex I and III 2 in mitochondrial respiratory chain supercomplexes of mammals, yeast, and plants. Proc Natl Acad Sci U S A 2018. [PMID: 29519876 PMCID: PMC5866595 DOI: 10.1073/pnas.1720702115] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
We used electron cryo-tomography and subtomogram averaging to investigate the structure of complex I and its supramolecular assemblies in the inner mitochondrial membrane of mammals, fungi, and plants. Tomographic volumes containing complex I were averaged at ∼4 nm resolution. Principal component analysis indicated that ∼60% of complex I formed a supercomplex with dimeric complex III, while ∼40% were not associated with other respiratory chain complexes. The mutual arrangement of complex I and III2 was essentially conserved in all supercomplexes investigated. In addition, up to two copies of monomeric complex IV were associated with the complex I1III2 assembly in bovine heart and the yeast Yarrowia lipolytica, but their positions varied. No complex IV was detected in the respiratory supercomplex of the plant Asparagus officinalis Instead, an ∼4.5-nm globular protein density was observed on the matrix side of the complex I membrane arm, which we assign to γ-carbonic anhydrase. Our results demonstrate that respiratory chain supercomplexes in situ have a conserved core of complex I and III2, but otherwise their stoichiometry and structure varies. The conserved features of supercomplex assemblies indicate an important role in respiratory electron transfer.
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Filipovic MR, Zivanovic J, Alvarez B, Banerjee R. Chemical Biology of H 2S Signaling through Persulfidation. Chem Rev 2018; 118:1253-1337. [PMID: 29112440 PMCID: PMC6029264 DOI: 10.1021/acs.chemrev.7b00205] [Citation(s) in RCA: 592] [Impact Index Per Article: 98.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Signaling by H2S is proposed to occur via persulfidation, a posttranslational modification of cysteine residues (RSH) to persulfides (RSSH). Persulfidation provides a framework for understanding the physiological and pharmacological effects of H2S. Due to the inherent instability of persulfides, their chemistry is understudied. In this review, we discuss the biologically relevant chemistry of H2S and the enzymatic routes for its production and oxidation. We cover the chemical biology of persulfides and the chemical probes for detecting them. We conclude by discussing the roles ascribed to protein persulfidation in cell signaling pathways.
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Affiliation(s)
- Milos R. Filipovic
- Univeristy of Bordeaux, IBGC, UMR 5095, F-33077 Bordeaux, France
- CNRS, IBGC, UMR 5095, F-33077 Bordeaux, France
| | - Jasmina Zivanovic
- Univeristy of Bordeaux, IBGC, UMR 5095, F-33077 Bordeaux, France
- CNRS, IBGC, UMR 5095, F-33077 Bordeaux, France
| | - Beatriz Alvarez
- Laboratorio de Enzimología, Facultad de Ciencias and Center for Free Radical and Biomedical Research, Universidad de la Republica, 11400 Montevideo, Uruguay
| | - Ruma Banerjee
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109-0600, United States
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Abstract
Mitochondria are the power stations of the eukaryotic cell, using the energy released by the oxidation of glucose and other sugars to produce ATP. Electrons are transferred from NADH, produced in the citric acid cycle in the mitochondrial matrix, to oxygen by a series of large protein complexes in the inner mitochondrial membrane, which create a transmembrane electrochemical gradient by pumping protons across the membrane. The flow of protons back into the matrix via a proton channel in the ATP synthase leads to conformational changes in the nucleotide binding pockets and the formation of ATP. The three proton pumping complexes of the electron transfer chain are NADH-ubiquinone oxidoreductase or complex I, ubiquinone-cytochrome c oxidoreductase or complex III, and cytochrome c oxidase or complex IV. Succinate dehydrogenase or complex II does not pump protons, but contributes reduced ubiquinone. The structures of complex II, III and IV were determined by x-ray crystallography several decades ago, but complex I and ATP synthase have only recently started to reveal their secrets by advances in x-ray crystallography and cryo-electron microscopy. The complexes I, III and IV occur to a certain extent as supercomplexes in the membrane, the so-called respirasomes. Several hypotheses exist about their function. Recent cryo-electron microscopy structures show the architecture of the respirasome with near-atomic detail. ATP synthase occurs as dimers in the inner mitochondrial membrane, which by their curvature are responsible for the folding of the membrane into cristae and thus for the huge increase in available surface that makes mitochondria the efficient energy plants of the eukaryotic cell.
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Affiliation(s)
- Joana S Sousa
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Edoardo D'Imprima
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Janet Vonck
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany.
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Scherr J, Parey K, Klusch N, Murphy BJ, Balser S, Neuhaus A, Zickermann V, Kühlbrandt W, Terfort A, Rhinow D. Self-Perforated Hydrogel Nanomembranes Facilitate Structural Analysis of Proteins by Electron Cryo-Microscopy. ACS NANO 2017; 11:6467-6473. [PMID: 28598595 DOI: 10.1021/acsnano.7b03099] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We developed a method to improve specimen preparation for electron cryo-microscopy of membrane proteins. The method features a perforated hydrogel nanomembrane that stabilizes the thin film of aqueous buffer spanning the holes of holey carbon films, while at the same time preventing the depletion of protein molecules from these holes. The membrane is obtained by cross-linking of thiolated polyglycerol dendrimer films on gold, which self-perforate upon transfer to holey carbon substrates, forming a sub-micron-sized hydrogel network. The perforated nanomembrane improves the distribution of the protein molecules in the ice considerably. This facilitates data acquisition as demonstrated with two eukaryotic membrane protein complexes.
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Affiliation(s)
- Julian Scherr
- Department of Chemistry, Institute of Inorganic and Analytical Chemistry, Goethe-University , Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Kristian Parey
- Department of Structural Biology, Max Planck Institute of Biophysics , Max-von-Laue-Str. 3, 60438 Frankfurt, Germany
| | - Niklas Klusch
- Department of Structural Biology, Max Planck Institute of Biophysics , Max-von-Laue-Str. 3, 60438 Frankfurt, Germany
| | - Bonnie J Murphy
- Department of Structural Biology, Max Planck Institute of Biophysics , Max-von-Laue-Str. 3, 60438 Frankfurt, Germany
| | - Sebastian Balser
- Department of Chemistry, Institute of Inorganic and Analytical Chemistry, Goethe-University , Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Alexander Neuhaus
- Department of Structural Biology, Max Planck Institute of Biophysics , Max-von-Laue-Str. 3, 60438 Frankfurt, Germany
| | - Volker Zickermann
- Structural Bioenergetics Group, Institute of Biochemistry II, Medical School, Goethe-University Frankfurt , Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Werner Kühlbrandt
- Department of Structural Biology, Max Planck Institute of Biophysics , Max-von-Laue-Str. 3, 60438 Frankfurt, Germany
| | - Andreas Terfort
- Department of Chemistry, Institute of Inorganic and Analytical Chemistry, Goethe-University , Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Daniel Rhinow
- Department of Structural Biology, Max Planck Institute of Biophysics , Max-von-Laue-Str. 3, 60438 Frankfurt, Germany
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