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Gupta C, Khaniya U, Chan CK, Dehez F, Shekhar M, Gunner MR, Sazanov L, Chipot C, Singharoy A. Charge Transfer and Chemo-Mechanical Coupling in Respiratory Complex I. J Am Chem Soc 2020; 142:9220-9230. [PMID: 32347721 DOI: 10.1021/jacs.9b13450] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The mitochondrial respiratory chain, formed by five protein complexes, utilizes energy from catabolic processes to synthesize ATP. Complex I, the first and the largest protein complex of the chain, harvests electrons from NADH to reduce quinone, while pumping protons across the mitochondrial membrane. Detailed knowledge of the working principle of such coupled charge-transfer processes remains, however, fragmentary due to bottlenecks in understanding redox-driven conformational transitions and their interplay with the hydrated proton pathways. Complex I from Thermus thermophilus encases 16 subunits with nine iron-sulfur clusters, reduced by electrons from NADH. Here, employing the latest crystal structure of T. thermophilus complex I, we have used microsecond-scale molecular dynamics simulations to study the chemo-mechanical coupling between redox changes of the iron-sulfur clusters and conformational transitions across complex I. First, we identify the redox switches within complex I, which allosterically couple the dynamics of the quinone binding pocket to the site of NADH reduction. Second, our free-energy calculations reveal that the affinity of the quinone, specifically menaquinone, for the binding-site is higher than that of its reduced, menaquinol form-a design essential for menaquinol release. Remarkably, the barriers to diffusive menaquinone dynamics are lesser than that of the more ubiquitous ubiquinone, and the naphthoquinone headgroup of the former furnishes stronger binding interactions with the pocket, favoring menaquinone for charge transport in T. thermophilus. Our computations are consistent with experimentally validated mutations and hierarchize the key residues into three functional classes, identifying new mutation targets. Third, long-range hydrogen-bond networks connecting the quinone-binding site to the transmembrane subunits are found to be responsible for proton pumping. Put together, the simulations reveal the molecular design principles linking redox reactions to quinone turnover to proton translocation in complex I.
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Affiliation(s)
- Chitrak Gupta
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85281, United States.,Biodesign Institute, Arizona State University, Tempe, Arizona 85281, United States
| | - Umesh Khaniya
- Department of Physics, City College of New York, New York, New York 10031, United States.,Department of Physics, City University of New York, New York, New York 10017, United States
| | - Chun Kit Chan
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | | | - Mrinal Shekhar
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - M R Gunner
- Department of Physics, City College of New York, New York, New York 10031, United States.,Department of Physics, City University of New York, New York, New York 10017, United States
| | - Leonid Sazanov
- Institute of Science and Technology, 3400 Klosterneuburg, Austria
| | - Christophe Chipot
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.,University of Lorraine, Nancy 54000, France
| | - Abhishek Singharoy
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85281, United States.,Biodesign Institute, Arizona State University, Tempe, Arizona 85281, United States
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Subrahmanian N, Castonguay AD, Fatnes TA, Hamel PP. Chlamydomonas reinhardtii as a plant model system to study mitochondrial complex I dysfunction. PLANT DIRECT 2020; 4:e00200. [PMID: 32025618 PMCID: PMC6996877 DOI: 10.1002/pld3.200] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 12/13/2019] [Accepted: 01/06/2020] [Indexed: 06/10/2023]
Abstract
Mitochondrial complex I, a proton-pumping NADH: ubiquinone oxidoreductase, is required for oxidative phosphorylation. However, the contribution of several human mutations to complex I deficiency is poorly understood. The unicellular alga Chlamydomonas reinhardtii was utilized to study complex I as, unlike in mammals, mutants with complete loss of the holoenzyme are viable. From a forward genetic screen for complex I-deficient insertional mutants, six mutants exhibiting complex I deficiency with assembly defects were isolated. Chlamydomonas mutants isolated from our screens, lacking the subunits NDUFV2 and NDUFB10, were used to reconstruct and analyze the effect of two human mutations in these subunit-encoding genes. The K209R substitution in NDUFV2, reported in Parkinson's disease patients, did not significantly affect the enzyme activity or assembly. The C107S substitution in the NDUFB10 subunit, reported in a case of fatal infantile cardiomyopathy, is part of a conserved C-(X)11-C motif. The cysteine substitutions, at either one or both positions, still allowed low levels of holoenzyme formation, indicating that this motif is crucial for complex I function but not strictly essential for assembly. We show that the algal mutants provide a simple and useful platform to delineate the consequences of patient mutations on complex I function.
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Affiliation(s)
- Nitya Subrahmanian
- Department of Molecular GeneticsThe Ohio State UniversityColumbusOHUSA
- Plant Cellular and Molecular Biology Graduate ProgramThe Ohio State UniversityColumbusOHUSA
| | - Andrew David Castonguay
- Department of Molecular GeneticsThe Ohio State UniversityColumbusOHUSA
- Molecular Genetics Graduate ProgramThe Ohio State UniversityColumbusOHUSA
| | - Thea Aspelund Fatnes
- Department of Molecular GeneticsThe Ohio State UniversityColumbusOHUSA
- Present address:
Fürst Medical LaboratoryOsloNorway
| | - Patrice Paul Hamel
- Department of Molecular GeneticsThe Ohio State UniversityColumbusOHUSA
- Department of Biological Chemistry and PharmacologyThe Ohio State UniversityColumbusOHUSA
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3
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Involvement of mitochondrial proteins in calcium signaling and cell death induced by staurosporine in Neurospora crassa. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:1064-74. [DOI: 10.1016/j.bbabio.2015.05.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2014] [Revised: 04/23/2015] [Accepted: 05/15/2015] [Indexed: 12/20/2022]
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Varghese F, Atcheson E, Bridges HR, Hirst J. Characterization of clinically identified mutations in NDUFV1, the flavin-binding subunit of respiratory complex I, using a yeast model system. Hum Mol Genet 2015; 24:6350-60. [PMID: 26345448 PMCID: PMC4614703 DOI: 10.1093/hmg/ddv344] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 08/18/2015] [Indexed: 02/02/2023] Open
Abstract
Dysfunctions in mitochondrial complex I (NADH:ubiquinone oxidoreductase) are both genetically and clinically highly diverse and a major cause of human mitochondrial diseases. The genetic determinants of individual clinical cases are increasingly being described, but how these genetic defects affect complex I on the molecular and cellular level, and have different clinical consequences in different individuals, is little understood. Furthermore, without molecular-level information innocent genetic variants may be misassigned as pathogenic. Here, we have used a yeast model system (Yarrowia lipolytica) to study the molecular consequences of 16 single amino acid substitutions, classified as pathogenic, in the NDUFV1 subunit of complex I. NDUFV1 binds the flavin cofactor that oxidizes NADH and is the site of complex I-mediated reactive oxygen species production. Seven mutations caused loss of complex I expression, suggesting they are detrimental but precluding further study. In two variants complex I was fully assembled but did not contain any flavin, and four mutations led to functionally compromised enzymes. Our study provides a molecular rationale for assignment of all these variants as pathogenic. However, three variants provided complex I that was functionally equivalent to the wild-type enzyme, challenging their assignment as pathogenic. By combining structural, bioinformatic and functional data, a simple scoring system for the initial evaluation of future NDUFV1 variants is proposed. Overall, our results broaden understanding of how mutations in this centrally important core subunit of complex I affect its function and provide a basis for understanding the role of NDUFV1 mutations in mitochondrial dysfunction.
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Affiliation(s)
- Febin Varghese
- Medical Research Council Mitochondrial Biology Unit, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK
| | - Erwan Atcheson
- Medical Research Council Mitochondrial Biology Unit, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK
| | - Hannah R Bridges
- Medical Research Council Mitochondrial Biology Unit, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK
| | - Judy Hirst
- Medical Research Council Mitochondrial Biology Unit, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK
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Ferreira M, Torraco A, Rizza T, Fattori F, Meschini MC, Castana C, Go NE, Nargang FE, Duarte M, Piemonte F, Dionisi-Vici C, Videira A, Vilarinho L, Santorelli FM, Carrozzo R, Bertini E. Progressive cavitating leukoencephalopathy associated with respiratory chain complex I deficiency and a novel mutation in NDUFS1. Neurogenetics 2011; 12:9-17. [DOI: 10.1007/s10048-010-0265-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Accepted: 11/12/2010] [Indexed: 11/24/2022]
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Blinova K, Levine RL, Boja ES, Griffiths GL, Shi ZD, Ruddy B, Balaban RS. Mitochondrial NADH fluorescence is enhanced by complex I binding. Biochemistry 2008; 47:9636-45. [PMID: 18702505 DOI: 10.1021/bi800307y] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Mitochondrial NADH fluorescence has been a useful tool in evaluating mitochondrial energetics both in vitro and in vivo. Mitochondrial NADH fluorescence is enhanced several-fold in the matrix through extended fluorescence lifetimes (EFL). However, the actual binding sites responsible for NADH EFL are unknown. We tested the hypothesis that NADH binding to Complex I is a significant source of mitochondrial NADH fluorescence enhancement. To test this hypothesis, the effect of Complex I binding on NADH fluorescence efficiency was evaluated in purified protein, and in native gels of the entire porcine heart mitochondria proteome. To avoid the oxidation of NADH in these preparations, we conducted the binding experiments under anoxic conditions in a specially designed apparatus. Purified intact Complex I enhanced NADH fluorescence in native gels approximately 10-fold. However, no enhancement was detected in denatured individual Complex I subunit proteins. In the Clear and Ghost native gels of the entire mitochondrial proteome, NADH fluorescence enhancement was localized to regions where NADH oxidation occurred in the presence of oxygen. Inhibitor and mass spectroscopy studies revealed that the fluorescence enhancement was specific to Complex I proteins. No fluorescence enhancement was detected for MDH or other dehydrogenases in this assay system, at physiological mole fractions of the matrix proteins. These data suggest that NADH associated with Complex I significantly contributes to the overall mitochondrial NADH fluorescence signal and provides an explanation for the well established close correlation of mitochondrial NADH fluorescence and the metabolic state.
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Affiliation(s)
- Ksenia Blinova
- Laboratory of Cardiac Energetics, National Heart Lung and Blood Institute, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, USA
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Koopman WJ, Verkaart S, van Emst-de Vries SE, Grefte S, Smeitink JA, Nijtmans LG, Willems PH. Mitigation of NADH: Ubiquinone oxidoreductase deficiency by chronic Trolox treatment. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2008; 1777:853-9. [DOI: 10.1016/j.bbabio.2008.03.028] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2008] [Revised: 03/04/2008] [Accepted: 03/19/2008] [Indexed: 12/21/2022]
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8
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Eukaryotic complex I: functional diversity and experimental systems to unravel the assembly process. Mol Genet Genomics 2008; 280:93-110. [DOI: 10.1007/s00438-008-0350-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2008] [Accepted: 05/01/2008] [Indexed: 10/21/2022]
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9
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Sazanov LA. Respiratory complex I: mechanistic and structural insights provided by the crystal structure of the hydrophilic domain. Biochemistry 2007; 46:2275-88. [PMID: 17274631 DOI: 10.1021/bi602508x] [Citation(s) in RCA: 171] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Complex I of respiratory chains plays a central role in cellular energy production. Mutations in its subunits lead to many human neurodegenerative diseases. Recently, a first atomic structure of the hydrophilic domain of complex I from Thermus thermophilus was determined. This domain represents a catalytic core of the enzyme. It consists of eight different subunits, contains all the redox centers, and comprises more than half of the entire complex. In this review, novel mechanistic implications of the structure are discussed, and the effects of many known mutations of complex I subunits are interpreted in a structural context.
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Affiliation(s)
- Leonid A Sazanov
- Medical Research Council Dunn Human Nutrition Unit, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 2XY, UK. sazanov@ mrc-dunn.cam.ac.uk
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Abstract
NADH:quinone oxidoreductase (complex I) pumps protons across the inner membrane of mitochondria or the plasma membrane of many bacteria. Human complex I is involved in numerous pathological conditions and degenerative processes. With 14 central and up to 32 accessory subunits, complex I is among the largest membrane-bound protein assemblies. The peripheral arm of the L-shaped molecule contains flavine mononucleotide and eight or nine iron-sulfur clusters as redox prosthetic groups. Seven of the iron-sulfur clusters form a linear electron transfer chain between flavine and quinone. In most organisms, the seven most hydrophobic subunits forming the core of the membrane arm are encoded by the mitochondrial genome. Most central subunits have evolved from subunits of different hydrogenases and bacterial Na+/H+ antiporters. This evolutionary origin is reflected in three functional modules of complex I. The coupling mechanism of complex I most likely involves semiquinone intermediates that drive proton pumping through redox-linked conformational changes.
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Affiliation(s)
- Ulrich Brandt
- Universität Frankfurt, Fachbereich Medizin, Zentrum der Biologischen Chemie, D-60590 Frankfurt am Main, Germany.
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Remacle C, Cardol P, Coosemans N, Gaisne M, Bonnefoy N. High-efficiency biolistic transformation of Chlamydomonas mitochondria can be used to insert mutations in complex I genes. Proc Natl Acad Sci U S A 2006; 103:4771-6. [PMID: 16537419 PMCID: PMC1450245 DOI: 10.1073/pnas.0509501103] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mitochondrial transformation of Chlamydomonas reinhardtii has been optimized by using a particle-gun device and cloned mitochondrial DNA or PCR fragments. A respiratory-deficient strain lacking a 1.2-kb mitochondrial DNA region including the left telomere and part of the cob gene could be rescued as well as a double-frameshift mutant in the mitochondrial cox1 and nd1 genes. High transformation efficiency has been achieved (100-250 transformants per microgram of DNA), the best results being obtained with linearized plasmid DNA. Molecular analysis of the transformants suggests that the right telomere sequence can be copied to reconstruct the left telomere by recombination. In addition, both nondeleterious and deleterious mutations could be introduced. Myxothiazol-resistant transformants have been created by introducing a nucleotide substitution into the cob gene. Similarly, an in-frame deletion of 23 codons has been created in the nd4 mitochondrial gene of both the deleted and frameshift recipient strains. These 23 codons are believed to encode the first transmembrane segment of the ND4 protein. This Deltand4 mutation causes a misassembly of complex I, with the accumulation of a subcomplex that is 250-kDa smaller than the wild-type complex I. The availability of efficient mitochondrial transformation in Chlamydomonas provides an invaluable tool for the study of mitochondrial biogenesis and, more specifically, for site-directed mutagenesis of mitochondrially encoded subunits of complex I, of special interest because the yeast Saccharomyces cerevisiae, whose mitochondrial genome can be manipulated virtually at will, is lacking complex I.
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Affiliation(s)
- Claire Remacle
- Génétique des Microorganismes, Département des Sciences de la Vie, Institut de Botanique B22, Université de Liège, B-4000 Liège, Belgium.
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Grad LI, Lemire BD. Riboflavin enhances the assembly of mitochondrial cytochrome c oxidase in C. elegans NADH-ubiquinone oxidoreductase mutants. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2006; 1757:115-22. [PMID: 16443191 DOI: 10.1016/j.bbabio.2005.11.009] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2005] [Revised: 10/21/2005] [Accepted: 11/28/2005] [Indexed: 12/12/2022]
Abstract
Mitochondrial respiratory chain dysfunction is responsible for a large variety of early and late-onset diseases. NADH-ubiquinone oxidoreductase (complex I) defects constitute the most commonly observed mitochondrial disorders. We have generated Caenorhabditis elegans strains with mutations in the 51 kDa active site subunit of complex I. These strains exhibit decreased NADH-dependent respiration and lactic acidosis, hallmark features of complex I deficiency. Surprisingly, the mutants display a significant decrease in the amount and activity of cytochrome c oxidase (complex IV). The metabolic and reproductive fitness of the mutants is markedly improved by riboflavin. In this study, we have examined how the assembly and activity of complexes I and IV are affected by riboflavin. Our results reveal that the mutations result in variable steady-state levels of different complex I subunits and in a significant reduction in the amount of COXI subunit. Using native gel electrophoresis, we detected assembly intermediates for both complexes I and IV. Riboflavin promotes the assembly of both complexes, resulting in increased catalytic activities. We propose that one primary pathogenic mechanism of some complex I mutations is to destabilize complex IV. Enhancing complex I assembly with riboflavin results in the added benefit of partially reversing the complex IV deficit.
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Affiliation(s)
- Leslie I Grad
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2H7
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Ushakova AV, Duarte M, Vinogradov AD, Videira A. The 29.9 kDa subunit of mitochondrial complex I is involved in the enzyme active/de-active transitions. J Mol Biol 2005; 351:327-33. [PMID: 16005890 DOI: 10.1016/j.jmb.2005.06.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2004] [Revised: 05/31/2005] [Accepted: 06/01/2005] [Indexed: 11/22/2022]
Abstract
Mitochondrial respiratory chain complex I undergoes transitions from active to de-activated forms. We have investigated the phenomenon in sub-mitochondrial particles from Neurospora crassa wild-type and a null-mutant lacking the 29.9 kDa nuclear-coded subunit of complex I. Based on enzymatic activities, genetic crosses and analysis of mitochondrial proteins in sucrose gradients, we found that about one-fifth of complex I with catalytic properties similar to the wild-type enzyme is assembled in the mutant. Mutant complex I still displays active/de-active transitions, indicating that other proteins are involved in the phenomenon. However, the kinetic characteristics of complex I active/de-active transitions in nuo29.9 differ from wild-type. The spontaneous de-activation of the mutant enzyme is much slower, implicating the 29.9 kDa polypeptide in this event. We suggest that the fungal 29.9 kDa protein and its homologues in other organisms may modulate the active/de-active transitions of complex I.
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Affiliation(s)
- Alexandra V Ushakova
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto, Portugal
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