1
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Grivennikova VG, Gladyshev GV, Vinogradov AD. Deactivation of mitochondrial NADH:ubiquinone oxidoreductase (respiratory complex I): Extrinsically affecting factors. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148207. [DOI: 10.1016/j.bbabio.2020.148207] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 03/13/2020] [Accepted: 04/14/2020] [Indexed: 12/14/2022]
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2
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Galkin A, Moncada S. Modulation of the conformational state of mitochondrial complex I as a target for therapeutic intervention. Interface Focus 2017; 7:20160104. [PMID: 28382200 DOI: 10.1098/rsfs.2016.0104] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
In recent years, there have been significant advances in our understanding of the functions of mitochondrial complex I other than the generation of energy. These include its role in generation of reactive oxygen species, involvement in the hypoxic tissue response and its possible regulation by nitric oxide (NO) metabolites. In this review, we will focus on the hypoxic conformational change of this mitochondrial enzyme, the so-called active/deactive transition. This conformational change is physiological and relevant to the understanding of certain pathological conditions including, in the cardiovascular system, ischaemia/reperfusion (I/R) damage. We will discuss how complex I can be affected by NO metabolites and will outline some potential mitochondria-targeted therapies in I/R damage.
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Affiliation(s)
- Alexander Galkin
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, 401 East 61st Street, 5th floor, New York, NY 10065, USA; Queens University Belfast, School of Biological Sciences, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Salvador Moncada
- Manchester Cancer Research Centre , University of Manchester , Wilmslow Road, Manchester M20 4QL , UK
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3
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Fiedorczuk K, Letts JA, Degliesposti G, Kaszuba K, Skehel M, Sazanov LA. Atomic structure of the entire mammalian mitochondrial complex I. Nature 2016; 538:406-410. [PMID: 27595392 DOI: 10.1038/nature19794] [Citation(s) in RCA: 359] [Impact Index Per Article: 44.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 08/26/2016] [Indexed: 12/15/2022]
Abstract
Mitochondrial complex I (also known as NADH:ubiquinone oxidoreductase) contributes to cellular energy production by transferring electrons from NADH to ubiquinone coupled to proton translocation across the membrane. It is the largest protein assembly of the respiratory chain with a total mass of 970 kilodaltons. Here we present a nearly complete atomic structure of ovine (Ovis aries) mitochondrial complex I at 3.9 Å resolution, solved by cryo-electron microscopy with cross-linking and mass-spectrometry mapping experiments. All 14 conserved core subunits and 31 mitochondria-specific supernumerary subunits are resolved within the L-shaped molecule. The hydrophilic matrix arm comprises flavin mononucleotide and 8 iron-sulfur clusters involved in electron transfer, and the membrane arm contains 78 transmembrane helices, mostly contributed by antiporter-like subunits involved in proton translocation. Supernumerary subunits form an interlinked, stabilizing shell around the conserved core. Tightly bound lipids (including cardiolipins) further stabilize interactions between the hydrophobic subunits. Subunits with possible regulatory roles contain additional cofactors, NADPH and two phosphopantetheine molecules, which are shown to be involved in inter-subunit interactions. We observe two different conformations of the complex, which may be related to the conformationally driven coupling mechanism and to the active-deactive transition of the enzyme. Our structure provides insight into the mechanism, assembly, maturation and dysfunction of mitochondrial complex I, and allows detailed molecular analysis of disease-causing mutations.
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Affiliation(s)
- Karol Fiedorczuk
- Institute of Science and Technology Austria, Klosterneuburg 3400, Austria.,MRC Mitochondrial Biology Unit, Cambridge CB2 0XY, UK
| | - James A Letts
- Institute of Science and Technology Austria, Klosterneuburg 3400, Austria
| | | | - Karol Kaszuba
- Institute of Science and Technology Austria, Klosterneuburg 3400, Austria
| | - Mark Skehel
- MRC Laboratory of Molecular Biology, Cambridge CB2 OQH, UK
| | - Leonid A Sazanov
- Institute of Science and Technology Austria, Klosterneuburg 3400, Austria
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4
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Bromley M, Johns A, Davies E, Fraczek M, Mabey Gilsenan J, Kurbatova N, Keays M, Kapushesky M, Gut M, Gut I, Denning DW, Bowyer P. Mitochondrial Complex I Is a Global Regulator of Secondary Metabolism, Virulence and Azole Sensitivity in Fungi. PLoS One 2016; 11:e0158724. [PMID: 27438017 PMCID: PMC4954691 DOI: 10.1371/journal.pone.0158724] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 06/21/2016] [Indexed: 12/12/2022] Open
Abstract
Recent estimates of the global burden of fungal disease suggest that that their incidence has been drastically underestimated and that mortality may rival that of malaria or tuberculosis. Azoles are the principal class of antifungal drug and the only available oral treatment for fungal disease. Recent occurrence and increase in azole resistance is a major concern worldwide. Known azole resistance mechanisms include over—expression of efflux pumps and mutation of the gene encoding the target protein cyp51a, however, for one of the most important fungal pathogens of humans, Aspergillus fumigatus, much of the observed azole resistance does not appear to involve such mechanisms. Here we present evidence that azole resistance in A. fumigatus can arise through mutation of components of mitochondrial complex I. Gene deletions of the 29.9KD subunit of this complex are azole resistant, less virulent and exhibit dysregulation of secondary metabolite gene clusters in a manner analogous to deletion mutants of the secondary metabolism regulator, LaeA. Additionally we observe that a mutation leading to an E180D amino acid change in the 29.9 KD subunit is strongly associated with clinical azole resistant A. fumigatus isolates. Evidence presented in this paper suggests that complex I may play a role in the hypoxic response and that one possible mechanism for cell death during azole treatment is a dysfunctional hypoxic response that may be restored by dysregulation of complex I. Both deletion of the 29.9 KD subunit of complex I and azole treatment alone profoundly change expression of gene clusters involved in secondary metabolism and immunotoxin production raising potential concerns about long term azole therapy.
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Affiliation(s)
- Mike Bromley
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, Faculty of Medicine and Human Sciences, University of Manchester, 2.24 Core technology Building, Grafton St., Manchester, M13 9NT, United Kingdom
| | - Anna Johns
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, Faculty of Medicine and Human Sciences, University of Manchester, 2.24 Core technology Building, Grafton St., Manchester, M13 9NT, United Kingdom
| | - Emma Davies
- National Aspergillosis Centre, University Hospital of South Manchester, University of Manchester, School of Translational Medicine, Manchester Academic Health Science Centre, 2nd Floor Education & Research Centre, University of Manchester, Manchester, M23 9LT, United Kingdom
| | - Marcin Fraczek
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, Faculty of Medicine and Human Sciences, University of Manchester, 2.24 Core technology Building, Grafton St., Manchester, M13 9NT, United Kingdom
| | - Jane Mabey Gilsenan
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, Faculty of Medicine and Human Sciences, University of Manchester, 2.24 Core technology Building, Grafton St., Manchester, M13 9NT, United Kingdom
| | - Natalya Kurbatova
- The EMBL-European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, United Kingdom
| | - Maria Keays
- The EMBL-European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, United Kingdom
| | - Misha Kapushesky
- The EMBL-European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, United Kingdom
| | - Marta Gut
- Centro Nacional de Analisis Genomico, Parc Cientific de Barcelona, Baldiri Reixac, 4, PCB - Tower I, 08028 Barcelona, Spain
| | - Ivo Gut
- Centro Nacional de Analisis Genomico, Parc Cientific de Barcelona, Baldiri Reixac, 4, PCB - Tower I, 08028 Barcelona, Spain
| | - David W. Denning
- National Aspergillosis Centre, University Hospital of South Manchester, University of Manchester, School of Translational Medicine, Manchester Academic Health Science Centre, 2nd Floor Education & Research Centre, University of Manchester, Manchester, M23 9LT, United Kingdom
| | - Paul Bowyer
- Manchester Fungal Infection Group, Institute of Inflammation and Repair, Faculty of Medicine and Human Sciences, University of Manchester, 2.24 Core technology Building, Grafton St., Manchester, M13 9NT, United Kingdom
- National Aspergillosis Centre, University Hospital of South Manchester, University of Manchester, School of Translational Medicine, Manchester Academic Health Science Centre, 2nd Floor Education & Research Centre, University of Manchester, Manchester, M23 9LT, United Kingdom
- * E-mail:
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5
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Kroll K, Shekhova E, Mattern DJ, Thywissen A, Jacobsen ID, Strassburger M, Heinekamp T, Shelest E, Brakhage AA, Kniemeyer O. The hypoxia-induced dehydrogenase HorA is required for coenzyme Q10 biosynthesis, azole sensitivity and virulence ofAspergillus fumigatus. Mol Microbiol 2016; 101:92-108. [DOI: 10.1111/mmi.13377] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/14/2016] [Indexed: 12/30/2022]
Affiliation(s)
- Kristin Kroll
- Department of Molecular and Applied Microbiology; Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI); Jena Germany
| | - Elena Shekhova
- Department of Molecular and Applied Microbiology; Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI); Jena Germany
| | - Derek J. Mattern
- Department of Molecular and Applied Microbiology; Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI); Jena Germany
| | - Andreas Thywissen
- Department of Molecular and Applied Microbiology; Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI); Jena Germany
| | - Ilse D. Jacobsen
- Research Group Microbial Immunology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI), Jena, and Friedrich Schiller University Jena; Jena Germany
| | - Maria Strassburger
- Department of Molecular and Applied Microbiology; Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI); Jena Germany
- Transfer Group Anti-Infectives, Leibniz Institute for Natural Product Research and Infection Biology (HKI); Jena Germany
| | - Thorsten Heinekamp
- Department of Molecular and Applied Microbiology; Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI); Jena Germany
- Department of Microbiology and Molecular Biology; Institute of Microbiology, Friedrich Schiller University; Jena Germany
| | - Ekaterina Shelest
- Research Group Systems Biology and Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI), Jena, and Friedrich Schiller University Jena; Jena Germany
| | - Axel A. Brakhage
- Department of Molecular and Applied Microbiology; Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI); Jena Germany
- Department of Microbiology and Molecular Biology; Institute of Microbiology, Friedrich Schiller University; Jena Germany
| | - Olaf Kniemeyer
- Department of Molecular and Applied Microbiology; Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI); Jena Germany
- Department of Microbiology and Molecular Biology; Institute of Microbiology, Friedrich Schiller University; Jena Germany
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6
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Wirth C, Brandt U, Hunte C, Zickermann V. Structure and function of mitochondrial complex I. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:902-14. [PMID: 26921811 DOI: 10.1016/j.bbabio.2016.02.013] [Citation(s) in RCA: 215] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 02/16/2016] [Accepted: 02/17/2016] [Indexed: 12/13/2022]
Abstract
Proton-pumping NADH:ubiquinone oxidoreductase (complex I) is the largest and most complicated enzyme of the respiratory chain. Fourteen central subunits represent the minimal form of complex I and can be assigned to functional modules for NADH oxidation, ubiquinone reduction, and proton pumping. In addition, the mitochondrial enzyme comprises some 30 accessory subunits surrounding the central subunits that are not directly associated with energy conservation. Complex I is known to release deleterious oxygen radicals (ROS) and its dysfunction has been linked to a number of hereditary and degenerative diseases. We here review recent progress in structure determination, and in understanding the role of accessory subunits and functional analysis of mitochondrial complex I. For the central subunits, structures provide insight into the arrangement of functional modules including the substrate binding sites, redox-centers and putative proton channels and pump sites. Only for two of the accessory subunits, detailed structures are available. Nevertheless, many of them could be localized in the overall structure of complex I, but most of these assignments have to be considered tentative. Strikingly, redox reactions and proton pumping machinery are spatially completely separated and the site of reduction for the hydrophobic substrate ubiquinone is found deeply buried in the hydrophilic domain of the complex. The X-ray structure of complex I from Yarrowia lipolytica provides clues supporting the previously proposed two-state stabilization change mechanism, in which ubiquinone redox chemistry induces conformational states and thereby drives proton pumping. The same structural rearrangements may explain the active/deactive transition of complex I implying an integrated mechanistic model for energy conversion and regulation. This article is part of a Special Issue entitled Respiratory complex I, edited by Volker Zickermann and Ulrich Brandt.
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Affiliation(s)
- Christophe Wirth
- Institute for Biochemistry and Molecular Biology, ZBMZ, BIOSS Centre for Biological Signalling Studies, University of Freiburg, Germany
| | - Ulrich Brandt
- Nijmegen Center for Mitochondrial Disorders, Radboud University Medical Center, Nijmegen, The Netherlands; Cluster of Excellence Frankfurt "Macromolecular Complexes, Goethe-University, Germany
| | - Carola Hunte
- Institute for Biochemistry and Molecular Biology, ZBMZ, BIOSS Centre for Biological Signalling Studies, University of Freiburg, Germany.
| | - Volker Zickermann
- Structural Bioenergetics Group, Institute of Biochemistry II, Medical School, Goethe-University, Frankfurt am Main, Germany; Cluster of Excellence Frankfurt "Macromolecular Complexes, Goethe-University, Germany.
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7
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Vinogradov AD, Grivennikova VG. Oxidation of NADH and ROS production by respiratory complex I. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1857:863-71. [PMID: 26571336 DOI: 10.1016/j.bbabio.2015.11.004] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 11/02/2015] [Accepted: 11/07/2015] [Indexed: 12/14/2022]
Abstract
Kinetic characteristics of the proton-pumping NADH:quinone reductases (respiratory complexes I) are reviewed. Unsolved problems of the redox-linked proton translocation activities are outlined. The parameters of complex I-mediated superoxide/hydrogen peroxide generation are summarized, and the physiological significance of mitochondrial ROS production is discussed. This article is part of a Special Issue entitled Respiratory complex I, edited by Volker Zickermann and Ulrich Brandt.
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Affiliation(s)
- Andrei D Vinogradov
- Department of Biochemistry, School of Biology, Moscow State University, Moscow 119991.
| | - Vera G Grivennikova
- Department of Biochemistry, School of Biology, Moscow State University, Moscow 119991
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8
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Molecular mechanism and physiological role of active-deactive transition of mitochondrial complex I. Biochem Soc Trans 2014; 41:1325-30. [PMID: 24059527 PMCID: PMC3990385 DOI: 10.1042/bst20130088] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The unique feature of mitochondrial complex I is the so-called A/D transition (active–deactive transition). The A-form catalyses rapid oxidation of NADH by ubiquinone (k ~104 min−1) and spontaneously converts into the D-form if the enzyme is idle at physiological temperatures. Such deactivation occurs in vitro in the absence of substrates or in vivo during ischaemia, when the ubiquinone pool is reduced. The D-form can undergo reactivation given both NADH and ubiquinone availability during slow (k ~1–10 min−1) catalytic turnover(s). We examined known conformational differences between the two forms and suggested a mechanism exerting A/D transition of the enzyme. In addition, we discuss the physiological role of maintaining the enzyme in the D-form during the ischaemic period. Accumulation of the D-form of the enzyme would prevent reverse electron transfer from ubiquinol to FMN which could lead to superoxide anion generation. Deactivation would also decrease the initial burst of respiration after oxygen reintroduction. Therefore the A/D transition could be an intrinsic protective mechanism for lessening oxidative damage during the early phase of reoxygenation. Exposure of Cys39 of mitochondrially encoded subunit ND3 makes the D-form susceptible for modification by reactive oxygen species and nitric oxide metabolites which arrests the reactivation of the D-form and inhibits the enzyme. The nature of thiol modification defines deactivation reversibility, the reactivation timescale, the status of mitochondrial bioenergetics and therefore the degree of recovery of the ischaemic tissues after reoxygenation.
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9
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Abstract
Mitochondrial complex I has a molecular mass of almost 1 MDa and comprises more than 40 polypeptides. Fourteen central subunits harbour the bioenergetic core functions. We are only beginning to understand the significance of the numerous accessory subunits. The present review addresses the role of accessory subunits for assembly, stability and regulation of complex I and for cellular functions not directly associated with redox-linked proton translocation.
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10
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Ciano M, Fuszard M, Heide H, Botting CH, Galkin A. Conformation-specific crosslinking of mitochondrial complex I. FEBS Lett 2013; 587:867-72. [PMID: 23454639 DOI: 10.1016/j.febslet.2013.02.039] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Revised: 02/11/2013] [Accepted: 02/14/2013] [Indexed: 11/17/2022]
Abstract
Complex I is the only component of the eukaryotic respiratory chain of which no high-resolution structure is yet available. A notable feature of mitochondrial complex I is the so-called active/de-active conformational transition of the idle enzyme from the active (A) to the de-active, (D) form. Using an amine- and sulfhydryl-reactive crosslinker of 6.8Å length (SPDP) we found that in the D-form of complex I the ND3 subunit crosslinked to the 39 kDa (NDUFA9) subunit. These proteins could not be crosslinked in the A-form. Most likely, both subunits are closely located in the critical junction region connecting the peripheral hydrophilic domain to the membrane arm of the enzyme where the entrance path for substrate ubiquinone is and where energy transduction takes place.
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Affiliation(s)
- Margherita Ciano
- Queen's University Belfast, School of Biological Sciences, Medical Biology Centre, Belfast, UK
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11
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Bowyer P, Mosquera J, Anderson M, Birch M, Bromley M, Denning DW. Identification of novel genes conferring altered azole susceptibility in Aspergillus fumigatus. FEMS Microbiol Lett 2012; 332:10-9. [PMID: 22509997 DOI: 10.1111/j.1574-6968.2012.02575.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Revised: 03/28/2012] [Accepted: 03/29/2012] [Indexed: 11/30/2022] Open
Abstract
Azoles are currently the mainstay of antifungal treatment both in agricultural and in clinical settings. Although the target site of azole action is well studied, the basis of azole resistance and the ultimate mode of action of the drug in fungi are poorly understood. To gain a deeper insight into these aspects of azole action, restriction-mediated plasmid integration (REMI) was used to create azole sensitive and resistant strains of the clinically important fungus Aspergillus fumigatus. Four azole sensitive insertions and four azole-resistant insertions were characterized. Three phenotypes could be re-created in wild-type AF210 by reintegration of rescued plasmid and a further four could be confirmed by complementation of the mutant phenotype with a copy of the wild-type gene predicted to be disrupted by the original insertional event. Six insertions were in genes not previously associated with azole sensitivity or resistance. Two insertions occur in transporter genes that may affect drug efflux, whereas others may affect transcriptional regulation of sterol biosynthesis genes and NADH metabolism in the mitochondrion. Two insertions are in genes of unknown function.
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Affiliation(s)
- Paul Bowyer
- Manchester Academic Health Science Centre, NIHR Translational Research Facility in Respiratory Medicine, University Hospital of South Manchester NHS Foundation Trust, The University of Manchester, Manchester, UK.
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12
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Duarte M, Videira A. Effects of mitochondrial complex III disruption in the respiratory chain of Neurospora crassa. Mol Microbiol 2009; 72:246-58. [DOI: 10.1111/j.1365-2958.2009.06643.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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13
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Marques I, Dencher NA, Videira A, Krause F. Supramolecular organization of the respiratory chain in Neurospora crassa mitochondria. EUKARYOTIC CELL 2007; 6:2391-405. [PMID: 17873079 PMCID: PMC2168242 DOI: 10.1128/ec.00149-07] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The existence of specific respiratory supercomplexes in mitochondria of most organisms has gained much momentum. However, its functional significance is still poorly understood. The availability of many deletion mutants in complex I (NADH:ubiquinone oxidoreductase) of Neurospora crassa, distinctly affected in the assembly process, offers unique opportunities to analyze the biogenesis of respiratory supercomplexes. Herein, we describe the role of complex I in assembly of respiratory complexes and supercomplexes as suggested by blue and colorless native polyacrylamide gel electrophoresis and mass spectrometry analyses of mildly solubilized mitochondria from the wild type and eight deletion mutants. As an important refinement of the fungal respirasome model, we found that the standard respiratory chain of N. crassa comprises putative complex I dimers in addition to I-III-IV and III-IV supercomplexes. Three Neurospora mutants able to assemble a complete complex I, lacking only the disrupted subunit, have respiratory supercomplexes, in particular I-III-IV supercomplexes and complex I dimers, like the wild-type strain. Furthermore, we were able to detect the I-III-IV supercomplexes in the nuo51 mutant with no overall enzymatic activity, representing the first example of inactive respirasomes. In addition, III-IV supercomplexes were also present in strains lacking an assembled complex I, namely, in four membrane arm subunit mutants as well as in the peripheral arm nuo30.4 mutant. In membrane arm mutants, high-molecular-mass species of the 30.4-kDa peripheral arm subunit comigrating with III-IV supercomplexes and/or the prohibitin complex were detected. The data presented herein suggest that the biogenesis of complex I is linked with its assembly into supercomplexes.
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Affiliation(s)
- Isabel Marques
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto, Portugal
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Gostimskaya IS, Cecchini G, Vinogradov AD. Topography and chemical reactivity of the active-inactive transition-sensitive SH-group in the mitochondrial NADH:ubiquinone oxidoreductase (Complex I). BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2006; 1757:1155-61. [PMID: 16777054 PMCID: PMC2292829 DOI: 10.1016/j.bbabio.2006.04.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2006] [Revised: 03/27/2006] [Accepted: 04/06/2006] [Indexed: 11/22/2022]
Abstract
The spatial arrangement and chemical reactivity of the activation-dependent thiol in the mitochondrial Complex I was studied using the membrane penetrating N-ethylmaleimide (NEM) and non-penetrating anionic 5,5'-dithiobis-(2-nitrobenzoate) (DTNB) as the specific inhibitors of the enzyme in mitochondria and inside-out submitochondrial particles (SMP). Both NEM and DTNB rapidly inhibited the de-activated Complex I in SMP. In mitochondria NEM caused rapid inhibition of Complex I, whereas the enzyme activity was insensitive to DTNB. In the presence of the channel-forming antibiotic alamethicin, mitochondrial Complex I became sensitive to DTNB. Neither active nor de-activated Complex I in SMP was inhibited by oxidized glutathione (10 mM, pH 8.0, 75 min). The data suggest that the active/de-active transition sulfhydryl group of Complex I which is sensitive to inhibition by NEM is located at the inner membrane-matrix interface. These data include the sidedness dependency of inhibition, effect of pH, ionic strength, and membrane bilayer modification on enzyme reactivity towards DTNB and its neutral analogue.
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Affiliation(s)
- Irina S. Gostimskaya
- Department of Biochemistry, School of Biology, Moscow State University, Moscow 119992, Russian Federation
| | - Gary Cecchini
- Molecular Biology Division, Veterans Affairs Medical Center, San Francisco, CA 94121, USA
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143, USA
| | - Andrei D. Vinogradov
- Department of Biochemistry, School of Biology, Moscow State University, Moscow 119992, Russian Federation
- Corresponding author. Tel./fax: +7 495 939 13 76. E-mail address: (A.D. Vinogradov)
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