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Esparza-Perusquía M, Langner T, García-Cruz G, Feldbrügge M, Zavala G, Pardo JP, Martínez F, Flores-Herrera O. Deletion of the ATP20 gene in Ustilago maydis produces an unstable dimer of F 1F O-ATP synthase associated with a decrease in mitochondrial ATP synthesis and a high H 2O 2 production. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148950. [PMID: 36509127 DOI: 10.1016/j.bbabio.2022.148950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 11/07/2022] [Accepted: 12/02/2022] [Indexed: 12/13/2022]
Abstract
The F1FO-ATP synthase uses the energy stored in the electrochemical proton gradient to synthesize ATP. This complex is found in the inner mitochondrial membrane as a monomer and dimer. The dimer shows higher ATPase activity than the monomer and is essential for cristae folding. The monomer-monomer interface is constituted by subunits a, i/j, e, g, and k. The role of the subunit g in a strict respiratory organism is unknown. A gene knockout was generated in Ustilago maydis to study the role of subunit g on mitochondrial metabolism and cristae architecture. Deletion of the ATP20 gene, encoding the g subunit, did not affect cell growth or glucose consumption, but biomass production was lower in the mutant strain (gΔ strain). Ultrastructure observations showed that mitochondrial size and cristae shape were similar in wild-type and gΔ strains. The mitochondrial membrane potential in both strains had a similar magnitude, but oxygen consumption was higher in the WT strain. ATP synthesis was 20 % lower in the gΔ strain. Additionally, the mutant strain expressed the alternative oxidase in the early stages of growth (exponential phase), probably as a response to ROS stress. Dimer from mutant strain was unstable to digitonin solubilization, avoiding its isolation and kinetic characterization. The isolated monomeric state activated by n-dodecyl-β-D-maltopyranoside showed similar kinetic constants to the monomer from the WT strain. A decrease in mitochondrial ATP synthesis and the presence of the AOX during the exponential growth phase suggests that deletion of the g gene induces ROS stress.
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Affiliation(s)
- Mercedes Esparza-Perusquía
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Apartado Postal 70-159, Coyoacán, 04510 México, D. F., Mexico
| | - Thorsten Langner
- Institute for Microbiology, Cluster of Excellence on Plant Sciences, Department of Biology, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany; The Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Giovanni García-Cruz
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Apartado Postal 70-159, Coyoacán, 04510 México, D. F., Mexico
| | - Michael Feldbrügge
- The Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Guadalupe Zavala
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001 Chamilpa, 62210 Cuernavaca, Morelos, Mexico
| | - Juan Pablo Pardo
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Apartado Postal 70-159, Coyoacán, 04510 México, D. F., Mexico
| | - Federico Martínez
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Apartado Postal 70-159, Coyoacán, 04510 México, D. F., Mexico
| | - Oscar Flores-Herrera
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Apartado Postal 70-159, Coyoacán, 04510 México, D. F., Mexico.
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2
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Huo LJ, Lu PY, Li DX, Shi XZ. The sORF-Encoded Peptides, ATP Synthase Subunits, Facilitate WSSV Duplication in Shrimp. Viruses 2022; 14:2449. [PMID: 36366547 PMCID: PMC9692589 DOI: 10.3390/v14112449] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 10/28/2022] [Accepted: 11/01/2022] [Indexed: 11/09/2022] Open
Abstract
Short open reading frames (sORFs) are a newly identified family of genes, and the functions of most sORF genes and their encoded peptides (SEPs) are still unknown. In this study, two ATP synthase subunits were identified in kuruma shrimp (Marsupenaeus japonicus) as SEPs, namely MjATP5I and MjATP5L. They were widely distributed in all of the tested tissues of shrimp and upregulated in hemocytes and intestines in response to WSSV challenge. The injection of recombinant proteins (rMjATP5I and rMjATP5L) increased the expression of Ie1 and Vp28, while the knockdown of MjATP5I and MjATP5L decreased the expression of Ie1 and Vp28. All of the results suggest that MjATP5I and MjATP5L were beneficial for WSSV replication. Further exploration found that MjATP5I and MjATP5L RNAi significantly improved the shrimp survival rates, reduced ATP production, and upregulated the expression of antimicrobial peptide genes post viral challenge, and the two ATPase subunits and Relish negatively regulated each other. These results reveal that MjATP5I and MjATP5L facilitated WSSV duplication by regulating the production of ATP contents and the expression of antimicrobial peptide genes in shrimp.
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Affiliation(s)
- Li-Jie Huo
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao 266237, China
| | - Peng-Yuan Lu
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao 266237, China
| | - Dian-Xiang Li
- Department of Biopharmacy, School of Biological Sciences and Biotechnology, University of Jinan, Jinan 250022, China
| | - Xiu-Zhen Shi
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao 266237, China
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3
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Yang G, Zhao T, Lu S, Weng J, Zeng X. T1121G Point Mutation in the Mitochondrial Gene COX1 Suppresses a Null Mutation in ATP23 Required for the Assembly of Yeast Mitochondrial ATP Synthase. Int J Mol Sci 2022; 23:ijms23042327. [PMID: 35216443 PMCID: PMC8877559 DOI: 10.3390/ijms23042327] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/10/2022] [Accepted: 02/16/2022] [Indexed: 02/04/2023] Open
Abstract
Nuclear-encoded Atp23 was previously shown to have dual functions, including processing the yeast Atp6 precursor and assisting the assembly of yeast mitochondrial ATP synthase. However, it remains unknown whether there are genes functionally complementary to ATP23 to rescue atp23 null mutant. In the present paper, we screen and characterize three revertants of atp23 null mutant and reveal a T1121G point mutation in the mitochondrial gene COX1 coding sequence, which leads to Val374Gly mutation in Cox1, the suppressor in the revertants. This was verified further by the partial restoration of mitochondrial ATP synthase assembly in atp23 null mutant transformed with exogenous hybrid COX1 T1121G mutant plasmid. The predicted tertiary structure of the Cox1 p.Val374Gly mutation showed no obvious difference from wild-type Cox1. By further chase labeling with isotope [35S]-methionine, we found that the stability of Atp6 of ATP synthase increased in the revertants compared with the atp23 null mutant. Taking all the data together, we revealed that the T1121G point mutation of mitochondrial gene COX1 could partially restore the unassembly of mitochondrial ATP synthase in atp23 null mutant by increasing the stability of Atp6. Therefore, this study uncovers a gene that is partially functionally complementary to ATP23 to rescue ATP23 deficiency, broadening our understanding of the relationship between yeast the cytochrome c oxidase complex and mitochondrial ATP synthase complex.
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4
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Ukolova IV. VJ21.089The subcompartmented oxphosomic model of the phosphorylating system organization in mitochondria. Vavilovskii Zhurnal Genet Selektsii 2021; 25:778-786. [PMID: 34950849 PMCID: PMC8651570 DOI: 10.18699/vj21.089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 09/17/2021] [Accepted: 09/18/2021] [Indexed: 11/19/2022] Open
Abstract
The oxidative phosphorylation (OXPHOS) system of mitochondria supports all the vitally important energy-consuming processes in eukaryotic cells, providing them with energy in the form of ATP. OXPHOS enzymes (complexes I-V) are located in the inner mitochondrial membrane, mainly in the cristae subcompartment. At present, there is a large body of data evidencing that the respiratory complexes I, III2 and IV under in vivo conditions can physically interact with each other in diverse stoichiometry, thereby forming supercomplexes. Despite active accumulation of knowledge about the structure of the main supercomplexes of the OXPHOS system, its physical and functional organization in vivo remains unclear. Contemporary models of the OXPHOS system's organization in the inner membrane of mitochondria are contradictory and presume the existence of either highly organized respiratory strings, or, by contrast, a set of randomly dispersed respiratory supercomplexes and complexes. Furthermore, it is assumed that ATP-synthase (complex V) does not form associations with respiratory enzymes and operates autonomously. Our latest data obtained on mitochondria of etiolated shoots of pea evidence the possibility of physical association between the respiratory supercomplexes and dimeric ATP-synthase. These data have allowed us to reconsider the contemporary concept of the phosphorylation system organization and propose a new subcompartmented oxphosomic model. According to this model, a substantial number of the OXPHOS complexes form oxphosomes, which in a def inite stoichiometry include complexes I-V and are located predominantly in the cristae subcompartment of mitochondria in the form of highly organized strings or patches. These suprastructures represent "mini-factories" for ATP production. It is assumed that such an organization (1) contributes to increasing the eff iciency of the OXPHOS system operation, (2) involves new levels of activity regulation, and (3) may determine the inner membrane morphology to some extent. The review discusses the proposed model in detail. For a better understanding of the matter, the history of development of concepts concerning the OXPHOS organization with the emphasis on recent contemporary models is brief ly considered. The principal experimental data accumulated over the past 40 years, which conf irm the validity of the oxphosomic hypothesis, are also provided.
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Affiliation(s)
- I V Ukolova
- Сибирский институт физиологии и биохимии растений Сибирского отделения Российской академии наук, Иркутск, Россия
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5
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Quintana-Cabrera R, Manjarrés-Raza I, Vicente-Gutiérrez C, Corrado M, Bolaños JP, Scorrano L. Opa1 relies on cristae preservation and ATP synthase to curtail reactive oxygen species accumulation in mitochondria. Redox Biol 2021; 41:101944. [PMID: 33780775 PMCID: PMC8039725 DOI: 10.1016/j.redox.2021.101944] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 02/26/2021] [Accepted: 03/10/2021] [Indexed: 12/21/2022] Open
Abstract
Reactive oxygen species (ROS) are a common product of active mitochondrial respiration carried in mitochondrial cristae, but whether cristae shape influences ROS levels is unclear. Here we report that the mitochondrial fusion and cristae shape protein Opa1 requires mitochondrial ATP synthase oligomers to reduce ROS accumulation. In cells fueled with galactose to force ATP production by mitochondria, cristae are enlarged, ATP synthase oligomers destabilized, and ROS accumulate. Opa1 prevents both cristae remodeling and ROS generation, without impinging on levels of mitochondrial antioxidant defense enzymes that are unaffected by Opa1 overexpression. Genetic and pharmacologic experiments indicate that Opa1 requires ATP synthase oligomerization and activity to reduce ROS levels upon a blockage of the electron transport chain. Our results indicate that the converging effect of Opa1 and mitochondrial ATP synthase on mitochondrial ultrastructure regulate ROS abundance to sustain cell viability.
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Affiliation(s)
- Rubén Quintana-Cabrera
- Institute of Functional Biology and Genomics (IBFG), University of Salamanca, CSIC, Salamanca, Spain; Institute of Biomedical Research of Salamanca (IBSAL), University Hospital of Salamanca, University of Salamanca, CSIC, Salamanca, Spain; CIBERFES, Institute of Health Carlos III, Madrid, Spain; Department of Biochemistry and Molecular Biology, University of Salamanca, Spain.
| | - Israel Manjarrés-Raza
- Institute of Functional Biology and Genomics (IBFG), University of Salamanca, CSIC, Salamanca, Spain; Institute of Biomedical Research of Salamanca (IBSAL), University Hospital of Salamanca, University of Salamanca, CSIC, Salamanca, Spain; CIBERFES, Institute of Health Carlos III, Madrid, Spain; Department of Biochemistry and Molecular Biology, University of Salamanca, Spain
| | - Carlos Vicente-Gutiérrez
- Institute of Functional Biology and Genomics (IBFG), University of Salamanca, CSIC, Salamanca, Spain; Institute of Biomedical Research of Salamanca (IBSAL), University Hospital of Salamanca, University of Salamanca, CSIC, Salamanca, Spain; CIBERFES, Institute of Health Carlos III, Madrid, Spain
| | - Mauro Corrado
- Department of Immunometabolism, Max Planck Institute of Epigenetics and Immunobiology, Freiburg Im Breisgau, Germany
| | - Juan P Bolaños
- Institute of Functional Biology and Genomics (IBFG), University of Salamanca, CSIC, Salamanca, Spain; Institute of Biomedical Research of Salamanca (IBSAL), University Hospital of Salamanca, University of Salamanca, CSIC, Salamanca, Spain; CIBERFES, Institute of Health Carlos III, Madrid, Spain; Department of Biochemistry and Molecular Biology, University of Salamanca, Spain
| | - Luca Scorrano
- Veneto Institute of Molecular Medicine, Padova, Italy; Department of Biology, University of Padova, Padova, Italy.
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6
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Frankovsky J, Vozáriková V, Nosek J, Tomáška Ľ. Mitochondrial protein phosphorylation in yeast revisited. Mitochondrion 2021; 57:148-162. [PMID: 33412333 DOI: 10.1016/j.mito.2020.12.016] [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] [Received: 10/25/2020] [Revised: 12/23/2020] [Accepted: 12/30/2020] [Indexed: 12/16/2022]
Abstract
Protein phosphorylation is one of the best-known post-translational modifications occurring in all domains of life. In eukaryotes, protein phosphorylation affects all cellular compartments including mitochondria. High-throughput techniques of mass spectrometry combined with cell fractionation and biochemical methods yielded thousands of phospho-sites on hundreds of mitochondrial proteins. We have compiled the information on mitochondrial protein kinases and phosphatases and their substrates in Saccharomyces cerevisiae and provide the current state-of-the-art overview of mitochondrial protein phosphorylation in this model eukaryote. Using several examples, we describe emerging features of the yeast mitochondrial phosphoproteome and present challenges lying ahead in this exciting field.
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Affiliation(s)
- Jan Frankovsky
- Department of Genetics, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, 842 15 Bratislava, Slovakia
| | - Veronika Vozáriková
- Department of Genetics, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, 842 15 Bratislava, Slovakia
| | - Jozef Nosek
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, 842 15 Bratislava, Slovakia
| | - Ľubomír Tomáška
- Department of Genetics, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, 842 15 Bratislava, Slovakia.
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7
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Ukolova IV, Kondakova MA, Kondratov IG, Sidorov AV, Borovskii GB, Voinikov VK. New insights into the organisation of the oxidative phosphorylation system in the example of pea shoot mitochondria. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2020; 1861:148264. [PMID: 32663476 DOI: 10.1016/j.bbabio.2020.148264] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 06/20/2020] [Accepted: 07/06/2020] [Indexed: 12/17/2022]
Abstract
The physical and functional organisation of the OXPHOS system in mitochondria in vivo remains elusive. At present, different models of OXPHOS arrangement, representing either highly ordered respiratory strings or, vice versa, a set of randomly dispersed supercomplexes and respiratory complexes, have been suggested. In the present study, we examined a supramolecular arrangement of the OXPHOS system in pea shoot mitochondria using digitonin solubilisation of its constituents, which were further analysed by classical BN-related techniques and a multidimensional gel electrophoresis system when required. As a result, in addition to supercomplexes I1III2, I1III2IVn and III2IV1-2, dimer V2, and individual complexes I-V previously detected in plant mitochondria, new OXPHOS structures were also revealed. Of them, (1) a megacomplex (IIxIIIyIVz)n including complex II, (2) respirasomes I2III4IVn with two copies of complex I and dimeric complex III2, (3) a minor new supercomplex IV1Va2 comigrating with I1III2, and (4) a second minor form of ATP synthase, Va, were found. The activity of singular complexes I, IV, and V was higher than the activity of the associated forms. The detection of new supercomplex IV1Va2, along with assemblies I1III2 and I1-2III2-4IVn, prompted us to suggest the occurrence of in vivo oxphosomes comprising complexes I, III2, IV, and V. The putative oxphosome's stoichiometry, historical background, assumed functional significance, and subcompartmental location are discussed herein.
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Affiliation(s)
- Irina V Ukolova
- Siberian Institute of Plant Physiology and Biochemistry SB RAS, 132, Lermontov St., Irkutsk 664033, Russia.
| | - Marina A Kondakova
- Siberian Institute of Plant Physiology and Biochemistry SB RAS, 132, Lermontov St., Irkutsk 664033, Russia
| | - Ilya G Kondratov
- Limnological Institute SB RAS, 3, Ulan-Batorskaya St., Irkutsk 664033, Russia
| | - Alexander V Sidorov
- Siberian Institute of Plant Physiology and Biochemistry SB RAS, 132, Lermontov St., Irkutsk 664033, Russia; Irkutsk State Medical University, 1, Krasnogo Vosstaniya St., Irkutsk 664003, Russia
| | - Gennadii B Borovskii
- Siberian Institute of Plant Physiology and Biochemistry SB RAS, 132, Lermontov St., Irkutsk 664033, Russia
| | - Victor K Voinikov
- Siberian Institute of Plant Physiology and Biochemistry SB RAS, 132, Lermontov St., Irkutsk 664033, Russia
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8
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Sunyer-Figueres M, Vázquez J, Mas A, Torija MJ, Beltran G. Transcriptomic Insights into the Effect of Melatonin in Saccharomyces cerevisiae in the Presence and Absence of Oxidative Stress. Antioxidants (Basel) 2020; 9:E947. [PMID: 33019712 PMCID: PMC7650831 DOI: 10.3390/antiox9100947] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 09/25/2020] [Accepted: 09/28/2020] [Indexed: 12/17/2022] Open
Abstract
Melatonin is a ubiquitous indolamine that plays important roles in various aspects of biological processes in mammals. In Saccharomyces cerevisiae, melatonin has been reported to exhibit antioxidant properties and to modulate the expression of some genes involved in endogenous defense systems. The aim of this study was to elucidate the role of supplemented melatonin at the transcriptional level in S. cerevisiae in the presence and absence of oxidative stress. This was achieved by exposing yeast cells pretreated with different melatonin concentrations to hydrogen peroxide and assessing the entry of melatonin into the cell and the yeast response at the transcriptional level (by microarray and qPCR analyses) and the physiological level (by analyzing changes in the lipid composition and mitochondrial activity). We found that exogenous melatonin crossed cellular membranes at nanomolar concentrations and modulated the expression of many genes, mainly downregulating the expression of mitochondrial genes in the absence of oxidative stress, triggering a hypoxia-like response, and upregulating them under stress, mainly the cytochrome complex and electron transport chain. Other categories that were enriched by the effect of melatonin were related to transport, antioxidant activity, signaling, and carbohydrate and lipid metabolism. The overall results suggest that melatonin is able to reprogram the cellular machinery to achieve tolerance to oxidative stress.
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Affiliation(s)
| | | | | | - María-Jesús Torija
- Departament de Bioquímica i Biotecnologia, Grup de Biotecnologia Enològica, Facultat d’Enologia, Universitat Rovira i Virgili, C/Marcel·lí Domingo, 1. 43007 Tarragona, Catalunya, Spain; (M.S.-F.); (J.V.); (A.M.); (G.B.)
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9
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Kinetic coupling of the respiratory chain with ATP synthase, but not proton gradients, drives ATP production in cristae membranes. Proc Natl Acad Sci U S A 2020; 117:2412-2421. [PMID: 31964824 DOI: 10.1073/pnas.1917968117] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Mitochondria have a characteristic ultrastructure with invaginations of the inner membrane called cristae that contain the protein complexes of the oxidative phosphorylation system. How this particular morphology of the respiratory membrane impacts energy conversion is currently unknown. One proposed role of cristae formation is to facilitate the establishment of local proton gradients to fuel ATP synthesis. Here, we determined the local pH values at defined sublocations within mitochondria of respiring yeast cells by fusing a pH-sensitive GFP to proteins residing in different mitochondrial subcompartments. Only a small proton gradient was detected over the inner membrane in wild type or cristae-lacking cells. Conversely, the obtained pH values did barely permit ATP synthesis in a reconstituted system containing purified yeast F1F0 ATP synthase, although, thermodynamically, a sufficiently high driving force was applied. At higher driving forces, where robust ATP synthesis was observed, a P-side pH value of 6 increased the ATP synthesis rate 3-fold compared to pH 7. In contrast, when ATP synthase was coreconstituted with an active proton-translocating cytochrome oxidase, ATP synthesis readily occurred at the measured, physiological pH values. Our study thus reveals that the morphology of the inner membrane does not influence the subcompartmental pH values and is not necessary for robust oxidative phosphorylation in mitochondria. Instead, it is likely that the dense packing of the oxidative phosphorylation complexes in the cristae membranes assists kinetic coupling between proton pumping and ATP synthesis.
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10
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Li XL, Huang WL, Yang HH, Jiang RC, Sun F, Wang HC, Zhao J, Xu CH, Tan BC. EMP18 functions in mitochondrial atp6 and cox2 transcript editing and is essential to seed development in maize. THE NEW PHYTOLOGIST 2019; 221:896-907. [PMID: 30168136 DOI: 10.1111/nph.15425] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 08/02/2018] [Indexed: 05/02/2023]
Abstract
RNA editing plays an important role in organellar gene expression in plants, and pentatricopeptide repeat (PPR) proteins are involved in this function. Because of its large family size, many PPR proteins are not known for their function and roles in plant growth and development. Through genetic and molecular analyses of the empty pericarp18 (emp18) mutant in maize (Zea mays), we cloned the Emp18 gene, revealed its molecular function, and defined its role in the mitochondrial complex assembly and seed development. Emp18 encodes a mitochondrial-localized DYW-PPR protein. Null mutation of Emp18 arrests embryo and endosperm development at an early stage in maize, resulting in embryo lethality. Mutants are deficient in the cytidine (C)-to-uridine (U) editing at atp6-635 and cox2-449, which converts a Leu to Pro in ATP6 and a Met to Thr in Cox2. The atp6 gene encodes the subunit a of F1 Fo -ATPase. The Leu to Pro alteration disrupts an α-helix of subunit a, resulting in a dramatic reduction in assembly and activity of F1 Fo -ATPase holoenzyme and an accumulation of free F1 -subcomplex. These results demonstrate that EMP18 functions in the C-to-U editing of atp6 and cox2, and is essential to mitochondrial biogenesis and seed development in maize.
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Affiliation(s)
- Xiu-Lan Li
- Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Wen-Long Huang
- Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Huan-Huan Yang
- Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Rui-Cheng Jiang
- Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Feng Sun
- Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Hong-Chun Wang
- Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Jiao Zhao
- Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Chun-Hui Xu
- Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Bao-Cai Tan
- Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, China
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11
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Quintana-Cabrera R, Quirin C, Glytsou C, Corrado M, Urbani A, Pellattiero A, Calvo E, Vázquez J, Enríquez JA, Gerle C, Soriano ME, Bernardi P, Scorrano L. The cristae modulator Optic atrophy 1 requires mitochondrial ATP synthase oligomers to safeguard mitochondrial function. Nat Commun 2018; 9:3399. [PMID: 30143614 PMCID: PMC6109181 DOI: 10.1038/s41467-018-05655-x] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 07/18/2018] [Indexed: 12/16/2022] Open
Abstract
It is unclear how the mitochondrial fusion protein Optic atrophy 1 (OPA1), which inhibits cristae remodeling, protects from mitochondrial dysfunction. Here we identify the mitochondrial F1Fo-ATP synthase as the effector of OPA1 in mitochondrial protection. In OPA1 overexpressing cells, the loss of proton electrochemical gradient caused by respiratory chain complex III inhibition is blunted and this protection is abolished by the ATP synthase inhibitor oligomycin. Mechanistically, OPA1 and ATP synthase can interact, but recombinant OPA1 fails to promote oligomerization of purified ATP synthase reconstituted in liposomes, suggesting that OPA1 favors ATP synthase oligomerization and reversal activity by modulating cristae shape. When ATP synthase oligomers are genetically destabilized by silencing the key dimerization subunit e, OPA1 is no longer able to preserve mitochondrial function and cell viability upon complex III inhibition. Thus, OPA1 protects mitochondria from respiratory chain inhibition by stabilizing cristae shape and favoring ATP synthase oligomerization. Mitochondrial cristae shape influences apoptosis and respiration. Here the authors show that the mitochondrial fusion protein OPA1 protects mitochondria from dysfunction by promoting ATP synthase oligomerization and reversal activity.
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Affiliation(s)
- Rubén Quintana-Cabrera
- Venetian Institute of Molecular Medicine, 35129, Padua, Italy.,Department of Biology, University of Padua, 35121, Padua, Italy.,University of Salamanca, Consejo Superior de Investigaciones Científicas CSIC, Institute of Functional Biology and Genomics, Salamanca, 37007, Spain.,Institute of Biomedical Research of Salamanca, University Hospital of Salamanca, University of Salamanca, CSIC, 37007, Salamanca, Spain.,CIBERFES, Institute of Health Carlos III, Madrid, Spain
| | - Charlotte Quirin
- Venetian Institute of Molecular Medicine, 35129, Padua, Italy.,Department of Biology, University of Padua, 35121, Padua, Italy
| | - Christina Glytsou
- Venetian Institute of Molecular Medicine, 35129, Padua, Italy.,Department of Biology, University of Padua, 35121, Padua, Italy.,Department of Pathology, NYU School of Medicine, 10016, New York, NY, USA
| | - Mauro Corrado
- Venetian Institute of Molecular Medicine, 35129, Padua, Italy.,Department of Biology, University of Padua, 35121, Padua, Italy.,Max Planck Institute of Immunology and Epigenetics, 79108, Freiburg im Breisgau, Germany
| | - Andrea Urbani
- Department of Biomedical Sciences, University of Padua, Padua, 35121, Italy
| | - Anna Pellattiero
- Venetian Institute of Molecular Medicine, 35129, Padua, Italy.,Department of Biology, University of Padua, 35121, Padua, Italy
| | - Enrique Calvo
- Centro Nacional de Investigaciones Cardiovasculares Carlos III, 28029, Madrid, Spain
| | - Jesús Vázquez
- Centro Nacional de Investigaciones Cardiovasculares Carlos III, 28029, Madrid, Spain
| | - José Antonio Enríquez
- Centro Nacional de Investigaciones Cardiovasculares Carlos III, 28029, Madrid, Spain.,CIBERFES, Institute of Health Carlos III, Madrid, Spain
| | - Christoph Gerle
- Institute for Protein Research, Osaka University, Suita, Osaka, Japan.,Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Kawaguchi, Japan
| | | | - Paolo Bernardi
- Department of Biomedical Sciences, University of Padua, Padua, 35121, Italy.,Institute of Neuroscience, Consiglio Nazionale delle Ricerche, Padua, Italy
| | - Luca Scorrano
- Venetian Institute of Molecular Medicine, 35129, Padua, Italy. .,Department of Biology, University of Padua, 35121, Padua, Italy.
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12
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Rampello NG, Stenger M, Westermann B, Osiewacz HD. Impact of F1Fo-ATP-synthase dimer assembly factors on mitochondrial function and organismic aging. MICROBIAL CELL 2018; 5:198-207. [PMID: 29610761 PMCID: PMC5878687 DOI: 10.15698/mic2018.04.625] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In aerobic organisms, mitochondrial F1Fo-ATP-synthase is the major site of ATP production. Beside this fundamental role, the protein complex is involved in shaping and maintenance of cristae. Previous electron microscopic studies identified the dissociation of F1Fo-ATP-synthase dimers and oligomers during organismic aging correlating with a massive remodeling of the mitochondrial inner membrane. Here we report results aimed to experimentally proof this impact and to obtain further insights into the control of these processes. We focused on the role of the two dimer assembly factors PaATPE and PaATPG of the aging model Podospora anserina. Ablation of either protein strongly affects mitochondrial function and leads to an accumulation of senescence markers demonstrating that the inhibition of dimer formation negatively influences vital functions and accelerates organismic aging. Our data validate a model that links mitochondrial membrane remodeling to aging and identify specific molecular components triggering this process.
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Affiliation(s)
- Nadia G Rampello
- Department of Biosciences, Molecular Developmental Biology, Institute of Molecular Biosciences and Cluster of Excellence Frankfurt Macromolecular Complexes, J. W. Goethe University, 60438 Frankfurt, Germany
| | - Maria Stenger
- Cell Biology and Electron Microscopy, University of Bayreuth, 95440 Bayreuth, Germany
| | - Benedikt Westermann
- Cell Biology and Electron Microscopy, University of Bayreuth, 95440 Bayreuth, Germany
| | - Heinz D Osiewacz
- Department of Biosciences, Molecular Developmental Biology, Institute of Molecular Biosciences and Cluster of Excellence Frankfurt Macromolecular Complexes, J. W. Goethe University, 60438 Frankfurt, Germany
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13
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Barbot M, Meinecke M. Reconstitutions of mitochondrial inner membrane remodeling. J Struct Biol 2016; 196:20-28. [DOI: 10.1016/j.jsb.2016.07.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 07/20/2016] [Accepted: 07/21/2016] [Indexed: 02/03/2023]
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14
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Klecker T, Wemmer M, Haag M, Weig A, Böckler S, Langer T, Nunnari J, Westermann B. Interaction of MDM33 with mitochondrial inner membrane homeostasis pathways in yeast. Sci Rep 2015; 5:18344. [PMID: 26669658 PMCID: PMC4680886 DOI: 10.1038/srep18344] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 11/16/2015] [Indexed: 12/31/2022] Open
Abstract
Membrane homeostasis affects mitochondrial dynamics, morphology, and function. Here we report genetic and proteomic data that reveal multiple interactions of Mdm33, a protein essential for normal mitochondrial structure, with components of phospholipid metabolism and mitochondrial inner membrane homeostasis. We screened for suppressors of MDM33 overexpression-induced growth arrest and isolated binding partners by immunoprecipitation of cross-linked cell extracts. These approaches revealed genetic and proteomic interactions of Mdm33 with prohibitins, Phb1 and Phb2, which are key components of mitochondrial inner membrane homeostasis. Lipid profiling by mass spectrometry of mitochondria isolated from Mdm33-overexpressing cells revealed that high levels of Mdm33 affect the levels of phosphatidylethanolamine and cardiolipin, the two key inner membrane phospholipids. Furthermore, we show that cells lacking Mdm33 show strongly decreased mitochondrial fission activity indicating that Mdm33 is critical for mitochondrial membrane dynamics. Our data suggest that MDM33 functionally interacts with components important for inner membrane homeostasis and thereby supports mitochondrial division.
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Affiliation(s)
- Till Klecker
- Universität Bayreuth, Zellbiologie, 95440 Bayreuth, Germany
| | - Megan Wemmer
- University of California Davis, Department of Molecular and Cellular Biology, Davis, CA 95616, USA
| | - Mathias Haag
- Universität zu Köln, Institut für Genetik, 50931 Köln, Germany
| | - Alfons Weig
- Universität Bayreuth, DNA Analytik, 95440 Bayreuth, Germany
| | - Stefan Böckler
- Universität Bayreuth, Zellbiologie, 95440 Bayreuth, Germany
| | - Thomas Langer
- Universität zu Köln, Institut für Genetik, 50931 Köln, Germany
| | - Jodi Nunnari
- University of California Davis, Department of Molecular and Cellular Biology, Davis, CA 95616, USA
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15
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Xu T, Pagadala V, Mueller DM. Understanding structure, function, and mutations in the mitochondrial ATP synthase. MICROBIAL CELL 2015; 2:105-125. [PMID: 25938092 PMCID: PMC4415626 DOI: 10.15698/mic2015.04.197] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The mitochondrial ATP synthase is a multimeric enzyme complex with an overall molecular weight of about 600,000 Da. The ATP synthase is a molecular motor composed of two separable parts: F1 and Fo. The F1 portion contains the catalytic sites for ATP synthesis and protrudes into the mitochondrial matrix. Fo forms a proton turbine that is embedded in the inner membrane and connected to the rotor of F1. The flux of protons flowing down a potential gradient powers the rotation of the rotor driving the synthesis of ATP. Thus, the flow of protons though Fo is coupled to the synthesis of ATP. This review will discuss the structure/function relationship in the ATP synthase as determined by biochemical, crystallographic, and genetic studies. An emphasis will be placed on linking the structure/function relationship with understanding how disease causing mutations or putative single nucleotide polymorphisms (SNPs) in genes encoding the subunits of the ATP synthase, will affect the function of the enzyme and the health of the individual. The review will start by summarizing the current understanding of the subunit composition of the enzyme and the role of the subunits followed by a discussion on known mutations and their effect on the activity of the ATP synthase. The review will conclude with a summary of mutations in genes encoding subunits of the ATP synthase that are known to be responsible for human disease, and a brief discussion on SNPs.
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Affiliation(s)
- Ting Xu
- Department of Biochemistry and Molecular Biology, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064
| | - Vijayakanth Pagadala
- Department of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC
| | - David M Mueller
- Department of Biochemistry and Molecular Biology, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064
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16
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Kühn K, Yin G, Duncan O, Law SR, Kubiszewski-Jakubiak S, Kaur P, Meyer E, Wang Y, Small CCDF, Giraud E, Narsai R, Whelan J. Decreasing electron flux through the cytochrome and/or alternative respiratory pathways triggers common and distinct cellular responses dependent on growth conditions. PLANT PHYSIOLOGY 2015; 167:228-50. [PMID: 25378695 PMCID: PMC4281006 DOI: 10.1104/pp.114.249946] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 10/29/2014] [Indexed: 05/18/2023]
Abstract
Diverse signaling pathways are activated by perturbation of mitochondrial function under different growth conditions.Mitochondria have emerged as an important organelle for sensing and coping with stress in addition to being the sites of important metabolic pathways. Here, responses to moderate light and drought stress were examined in different Arabidopsis (Arabidopsis thaliana) mutant plants lacking a functional alternative oxidase (alternative oxidase1a [aox1a]), those with reduced cytochrome electron transport chain capacity (T3/T7 bacteriophage-type RNA polymerase, mitochondrial, and plastidial [rpoTmp]), and double mutants impaired in both pathways (aox1a:rpoTmp). Under conditions considered optimal for growth, transcriptomes of aox1a and rpoTmp were distinct. Under adverse growth conditions, however, transcriptome changes in aox1a and rpoTmp displayed a highly significant overlap and were indicative of a common mitochondrial stress response and down-regulation of photosynthesis. This suggests that the role of mitochondria to support photosynthesis is provided through either the alternative pathway or the cytochrome pathway, and when either pathway is inhibited, such as under environmental stress, a common, dramatic, and succinct mitochondrial signal is activated to alter energy metabolism in both organelles. aox1a:rpoTmp double mutants grown under optimal conditions showed dramatic reductions in biomass production compared with aox1a and rpoTmp and a transcriptome that was distinct from aox1a or rpoTmp. Transcript data indicating activation of mitochondrial biogenesis in aox1a:rpoTmp were supported by a proteomic analysis of over 200 proteins. Under optimal conditions, aox1a:rpoTmp plants seemed to switch on many of the typical mitochondrial stress regulators. Under adverse conditions, aox1a:rpoTmp turned off these responses and displayed a biotic stress response. Taken together, these results highlight the diverse signaling pathways activated by the perturbation of mitochondrial function under different growth conditions.
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Affiliation(s)
- Kristina Kühn
- Molekulare Zellbiologie der Pflanzen, Institut für Biologie, Humboldt-Universität zu Berlin, D-10115 Berlin, Germany (K.K.);Australian Research Council Centre of Excellence in Plant Energy Biology (G.Y., O.D., S.K.-J., C.C.d.F.S.) andCentre for Plant Genetics and Breeding (P.K.), University of Western Australia, Crawley, Western Australia 6009, Australia;National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China (G.Y.);Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Science, La Trobe University, Bundoora, Victoria 3083, Australia (S.R.L., Y.W., R.N., J.W.);Department of Organelle Biology and Biotechnology, Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany (E.M.); andIllumina, Inc., Scoresby, Victoria 3179, Australia (E.G.)
| | - Guangkun Yin
- Molekulare Zellbiologie der Pflanzen, Institut für Biologie, Humboldt-Universität zu Berlin, D-10115 Berlin, Germany (K.K.);Australian Research Council Centre of Excellence in Plant Energy Biology (G.Y., O.D., S.K.-J., C.C.d.F.S.) andCentre for Plant Genetics and Breeding (P.K.), University of Western Australia, Crawley, Western Australia 6009, Australia;National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China (G.Y.);Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Science, La Trobe University, Bundoora, Victoria 3083, Australia (S.R.L., Y.W., R.N., J.W.);Department of Organelle Biology and Biotechnology, Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany (E.M.); andIllumina, Inc., Scoresby, Victoria 3179, Australia (E.G.)
| | - Owen Duncan
- Molekulare Zellbiologie der Pflanzen, Institut für Biologie, Humboldt-Universität zu Berlin, D-10115 Berlin, Germany (K.K.);Australian Research Council Centre of Excellence in Plant Energy Biology (G.Y., O.D., S.K.-J., C.C.d.F.S.) andCentre for Plant Genetics and Breeding (P.K.), University of Western Australia, Crawley, Western Australia 6009, Australia;National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China (G.Y.);Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Science, La Trobe University, Bundoora, Victoria 3083, Australia (S.R.L., Y.W., R.N., J.W.);Department of Organelle Biology and Biotechnology, Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany (E.M.); andIllumina, Inc., Scoresby, Victoria 3179, Australia (E.G.)
| | - Simon R Law
- Molekulare Zellbiologie der Pflanzen, Institut für Biologie, Humboldt-Universität zu Berlin, D-10115 Berlin, Germany (K.K.);Australian Research Council Centre of Excellence in Plant Energy Biology (G.Y., O.D., S.K.-J., C.C.d.F.S.) andCentre for Plant Genetics and Breeding (P.K.), University of Western Australia, Crawley, Western Australia 6009, Australia;National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China (G.Y.);Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Science, La Trobe University, Bundoora, Victoria 3083, Australia (S.R.L., Y.W., R.N., J.W.);Department of Organelle Biology and Biotechnology, Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany (E.M.); andIllumina, Inc., Scoresby, Victoria 3179, Australia (E.G.)
| | - Szymon Kubiszewski-Jakubiak
- Molekulare Zellbiologie der Pflanzen, Institut für Biologie, Humboldt-Universität zu Berlin, D-10115 Berlin, Germany (K.K.);Australian Research Council Centre of Excellence in Plant Energy Biology (G.Y., O.D., S.K.-J., C.C.d.F.S.) andCentre for Plant Genetics and Breeding (P.K.), University of Western Australia, Crawley, Western Australia 6009, Australia;National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China (G.Y.);Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Science, La Trobe University, Bundoora, Victoria 3083, Australia (S.R.L., Y.W., R.N., J.W.);Department of Organelle Biology and Biotechnology, Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany (E.M.); andIllumina, Inc., Scoresby, Victoria 3179, Australia (E.G.)
| | - Parwinder Kaur
- Molekulare Zellbiologie der Pflanzen, Institut für Biologie, Humboldt-Universität zu Berlin, D-10115 Berlin, Germany (K.K.);Australian Research Council Centre of Excellence in Plant Energy Biology (G.Y., O.D., S.K.-J., C.C.d.F.S.) andCentre for Plant Genetics and Breeding (P.K.), University of Western Australia, Crawley, Western Australia 6009, Australia;National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China (G.Y.);Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Science, La Trobe University, Bundoora, Victoria 3083, Australia (S.R.L., Y.W., R.N., J.W.);Department of Organelle Biology and Biotechnology, Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany (E.M.); andIllumina, Inc., Scoresby, Victoria 3179, Australia (E.G.)
| | - Etienne Meyer
- Molekulare Zellbiologie der Pflanzen, Institut für Biologie, Humboldt-Universität zu Berlin, D-10115 Berlin, Germany (K.K.);Australian Research Council Centre of Excellence in Plant Energy Biology (G.Y., O.D., S.K.-J., C.C.d.F.S.) andCentre for Plant Genetics and Breeding (P.K.), University of Western Australia, Crawley, Western Australia 6009, Australia;National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China (G.Y.);Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Science, La Trobe University, Bundoora, Victoria 3083, Australia (S.R.L., Y.W., R.N., J.W.);Department of Organelle Biology and Biotechnology, Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany (E.M.); andIllumina, Inc., Scoresby, Victoria 3179, Australia (E.G.)
| | - Yan Wang
- Molekulare Zellbiologie der Pflanzen, Institut für Biologie, Humboldt-Universität zu Berlin, D-10115 Berlin, Germany (K.K.);Australian Research Council Centre of Excellence in Plant Energy Biology (G.Y., O.D., S.K.-J., C.C.d.F.S.) andCentre for Plant Genetics and Breeding (P.K.), University of Western Australia, Crawley, Western Australia 6009, Australia;National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China (G.Y.);Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Science, La Trobe University, Bundoora, Victoria 3083, Australia (S.R.L., Y.W., R.N., J.W.);Department of Organelle Biology and Biotechnology, Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany (E.M.); andIllumina, Inc., Scoresby, Victoria 3179, Australia (E.G.)
| | - Catherine Colas des Francs Small
- Molekulare Zellbiologie der Pflanzen, Institut für Biologie, Humboldt-Universität zu Berlin, D-10115 Berlin, Germany (K.K.);Australian Research Council Centre of Excellence in Plant Energy Biology (G.Y., O.D., S.K.-J., C.C.d.F.S.) andCentre for Plant Genetics and Breeding (P.K.), University of Western Australia, Crawley, Western Australia 6009, Australia;National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China (G.Y.);Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Science, La Trobe University, Bundoora, Victoria 3083, Australia (S.R.L., Y.W., R.N., J.W.);Department of Organelle Biology and Biotechnology, Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany (E.M.); andIllumina, Inc., Scoresby, Victoria 3179, Australia (E.G.)
| | - Estelle Giraud
- Molekulare Zellbiologie der Pflanzen, Institut für Biologie, Humboldt-Universität zu Berlin, D-10115 Berlin, Germany (K.K.);Australian Research Council Centre of Excellence in Plant Energy Biology (G.Y., O.D., S.K.-J., C.C.d.F.S.) andCentre for Plant Genetics and Breeding (P.K.), University of Western Australia, Crawley, Western Australia 6009, Australia;National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China (G.Y.);Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Science, La Trobe University, Bundoora, Victoria 3083, Australia (S.R.L., Y.W., R.N., J.W.);Department of Organelle Biology and Biotechnology, Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany (E.M.); andIllumina, Inc., Scoresby, Victoria 3179, Australia (E.G.)
| | - Reena Narsai
- Molekulare Zellbiologie der Pflanzen, Institut für Biologie, Humboldt-Universität zu Berlin, D-10115 Berlin, Germany (K.K.);Australian Research Council Centre of Excellence in Plant Energy Biology (G.Y., O.D., S.K.-J., C.C.d.F.S.) andCentre for Plant Genetics and Breeding (P.K.), University of Western Australia, Crawley, Western Australia 6009, Australia;National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China (G.Y.);Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Science, La Trobe University, Bundoora, Victoria 3083, Australia (S.R.L., Y.W., R.N., J.W.);Department of Organelle Biology and Biotechnology, Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany (E.M.); andIllumina, Inc., Scoresby, Victoria 3179, Australia (E.G.)
| | - James Whelan
- Molekulare Zellbiologie der Pflanzen, Institut für Biologie, Humboldt-Universität zu Berlin, D-10115 Berlin, Germany (K.K.);Australian Research Council Centre of Excellence in Plant Energy Biology (G.Y., O.D., S.K.-J., C.C.d.F.S.) andCentre for Plant Genetics and Breeding (P.K.), University of Western Australia, Crawley, Western Australia 6009, Australia;National Genebank, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China (G.Y.);Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Science, La Trobe University, Bundoora, Victoria 3083, Australia (S.R.L., Y.W., R.N., J.W.);Department of Organelle Biology and Biotechnology, Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany (E.M.); andIllumina, Inc., Scoresby, Victoria 3179, Australia (E.G.)
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17
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Jimenez L, Laporte D, Duvezin-Caubet S, Courtout F, Sagot I. Mitochondrial ATP synthases cluster as discrete domains that reorganize with the cellular demand for oxidative phosphorylation. J Cell Sci 2013; 127:719-26. [PMID: 24338369 DOI: 10.1242/jcs.137141] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Mitochondria are double membrane-bounded organelles that form a dynamic tubular network. Mitochondria energetic functions depend on a complex internal architecture. Cristae, inner membrane invaginations that fold into the matrix space, are proposed to be the site of oxidative phosphorylation, reactions by which ATP synthase produces ATP. ATP synthase is also thought to have a role in crista morphogenesis. To date, the exploration of the processes regulating mitochondrial internal compartmentalization have been mostly limited to electron microscopy. Here, we describe ATP synthase localization in living yeast cells and show that it clusters as discrete inner membrane domains. These domains are dynamic within the mitochondrial network. They are impaired in mutants defective in crista morphology and partially overlap with the crista-associated MICOS-MINOS-MITOS complex. Finally, ATP synthase occupancy increases with the cellular demand for OXPHOS. Overall our data suggest that domains in which ATP synthases are clustered correspond to mitochondrial cristae. Being able to follow mitochondrial sub-compartments in living yeast cells opens new avenues to explore the mechanisms involved in inner membrane remodeling, an architectural feature crucial for mitochondrial activities.
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Affiliation(s)
- Laure Jimenez
- Université de Bordeaux, Institut de Biochimie et Génétique Cellulaires, Unité Mixte de Recherche 5095, Centre National de la Recherche Scientifique, Université Victor Segalen/Bordeaux II, F-33077 Bordeaux Cedex, France
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18
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ATP synthase oligomerization: From the enzyme models to the mitochondrial morphology. Int J Biochem Cell Biol 2013; 45:99-105. [DOI: 10.1016/j.biocel.2012.05.017] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2012] [Revised: 05/18/2012] [Accepted: 05/24/2012] [Indexed: 01/03/2023]
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19
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Structure of the yeast F1Fo-ATP synthase dimer and its role in shaping the mitochondrial cristae. Proc Natl Acad Sci U S A 2012; 109:13602-7. [PMID: 22864911 DOI: 10.1073/pnas.1204593109] [Citation(s) in RCA: 353] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We used electron cryotomography of mitochondrial membranes from wild-type and mutant Saccharomyces cerevisiae to investigate the structure and organization of ATP synthase dimers in situ. Subtomogram averaging of the dimers to 3.7 nm resolution revealed a V-shaped structure of twofold symmetry, with an angle of 86° between monomers. The central and peripheral stalks are well resolved. The monomers interact within the membrane at the base of the peripheral stalks. In wild-type mitochondria ATP synthase dimers are found in rows along the highly curved cristae ridges, and appear to be crucial for membrane morphology. Strains deficient in the dimer-specific subunits e and g or the first transmembrane helix of subunit 4 lack both dimers and lamellar cristae. Instead, cristae are either absent or balloon-shaped, with ATP synthase monomers distributed randomly in the membrane. Computer simulations indicate that isolated dimers induce a plastic deformation in the lipid bilayer, which is partially relieved by their side-by-side association. We propose that the assembly of ATP synthase dimer rows is driven by the reduction in the membrane elastic energy, rather than by direct protein contacts, and that the dimer rows enable the formation of highly curved ridges in mitochondrial cristae.
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20
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Gong L, Ramm G, Devenish RJ, Prescott M. HcRed, a genetically encoded fluorescent binary cross-linking agent for cross-linking of mitochondrial ATP synthase in Saccharomyces cerevisiae. PLoS One 2012; 7:e35095. [PMID: 22496895 PMCID: PMC3319629 DOI: 10.1371/journal.pone.0035095] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 03/08/2012] [Indexed: 12/02/2022] Open
Abstract
Genetically encoded fluorescent cross-linking agents represent powerful tools useful both for visualising and modulating protein interactions in living cells. The far-red fluorescent protein HcRed, which is fluorescent only in a dimer form, can be used to promote the homo-dimerisation of target proteins, and thereby yield useful information about biological processes. We have in yeast cells expressed HcRed fused to a subunit of mitochondrial ATP synthase (mtATPase). This resulted in cross-linking of the large multi-subunit mtATPase complex within the inner-membrane of the mitochondrion. Fluorescence microscopy revealed aberrant mitochondrial morphology, and mtATPase complexes isolated from mitochondria were recovered as fluorescent dimers under conditions where complexes from control mitochondria were recovered as monomers. When viewed by electron microscopy normal cristae were absent from mitochondria in cells in which mATPase complexes were cross-linked. mtATPase dimers are believed to be the building blocks that are assembled into supramolecular mtATPase ribbons that promote the formation of mitochondrial cristae. We propose that HcRed cross-links mATPase complexes in the mitochondrial membrane hindering the normal assembly/disassembly of the supramolecular forms of mtATPase.
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Affiliation(s)
- Lan Gong
- Department of Biochemistry and Molecular Biology, Monash University, Clayton Campus, Victoria, Australia
- ARC Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Clayton Campus, Victoria, Australia
| | - Georg Ramm
- Department of Biochemistry and Molecular Biology, Monash University, Clayton Campus, Victoria, Australia
| | - Rodney J. Devenish
- Department of Biochemistry and Molecular Biology, Monash University, Clayton Campus, Victoria, Australia
- ARC Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Clayton Campus, Victoria, Australia
| | - Mark Prescott
- Department of Biochemistry and Molecular Biology, Monash University, Clayton Campus, Victoria, Australia
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21
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ATP synthase superassemblies in animals and plants: Two or more are better. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2011; 1807:1185-97. [PMID: 21679683 DOI: 10.1016/j.bbabio.2011.05.023] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 05/30/2011] [Accepted: 05/31/2011] [Indexed: 12/11/2022]
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22
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Proton transport coupled ATP synthesis by the purified yeast H+ -ATP synthase in proteoliposomes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:1828-37. [PMID: 20691145 DOI: 10.1016/j.bbabio.2010.07.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Revised: 07/27/2010] [Accepted: 07/29/2010] [Indexed: 11/20/2022]
Abstract
The H(+)/ATP synthase from yeast mitochondria, MF₀F₁, was purified and reconstituted into liposomes prepared from phosphatidylcholine and phosphatidic acid. Analysis by mass spectrometry revealed the presence of all subunits of the yeast enzyme with the exception of the K-subunit. The MF₀F₁ liposomes were energized by acid-base transitions (DeltapH) and a K(+)/valinomycin diffusion potential (Deltaphi). ATP synthesis was completely abolished by the addition of uncouplers as well as by the inhibitor oligomycin. The rate of ATP synthesis was optimized as a function of various parameters and reached a maximum value (turnover number) of 120s⁻¹ at a transmembrane pH difference of 3.2 units (at pH(in)=4.8 and pH(out)=8.0) and a Deltaphi of 133mV (Nernst potential). Functional studies showed that the monomeric MF₀F₁, was fully active in ATP synthesis. The turnover increased in a sigmoidal way with increasing internal and decreasing external proton concentration. The dependence of the turnover on the phosphate concentration and the dependence of K(M) on pH(out) indicated that the substrate for ATP synthesis is the monoanionic phosphate species H₂PO⁻₄.
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Lenaz G, Genova ML. Structural and functional organization of the mitochondrial respiratory chain: a dynamic super-assembly. Int J Biochem Cell Biol 2009; 41:1750-1772. [PMID: 19711505 DOI: 10.1016/j.biocel.2009.04.003] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The structural organization of the mitochondrial oxidative phosphorylation (OXPHOS) system has received large attention in the past and most investigations led to the conclusion that the respiratory enzymatic complexes are randomly dispersed in the lipid bilayer of the inner membrane and functionally connected by fast diffusion of smaller redox components, Coenzyme Q and cytochrome c. More recent investigations by native gel electrophoresis, however, have shown the existence of supramolecular associations of the respiratory complexes, confirmed by electron microscopy analysis and single particle image processing. Flux control analysis has demonstrated that Complexes I and III in mammalian mitochondria and Complexes I, III, and IV in plant mitochondria kinetically behave as single units with control coefficients approaching unity for each single component, suggesting the existence of substrate channelling within the supercomplexes. The reasons why the presence of substrate channelling for Coenzyme Q and cytochrome c was overlooked in the past are analytically discussed. The review also discusses the forces and the conditions responsible for the formation of the supramolecular units. The function of the supercomplexes appears not to be restricted to kinetic advantages in electron transfer: we discuss evidence on their role in the stability and assembly of the individual complexes and in preventing excess oxygen radical formation. Finally, there is increasing evidence that disruption of the supercomplex organization leads to functional derangements responsible for pathological changes.
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Affiliation(s)
- Giorgio Lenaz
- Dipartimento di Biochimica G. Moruzzi, Università di Bologna, Via Irnerio 48, 40126 Bologna, Italy.
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Supramolecular organization of ATP synthase and respiratory chain in mitochondrial membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2009; 1787:672-80. [DOI: 10.1016/j.bbabio.2008.12.016] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2008] [Revised: 12/29/2008] [Accepted: 12/29/2008] [Indexed: 01/05/2023]
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Boyle GM, Roucou X, Nagley P, Devenish RJ, Prescott M. Modulation at a distance of proton conductance through the Saccharomyces cerevisiae mitochondrial F1F0-ATP synthase by variants of the oligomycin sensitivity-conferring protein containing substitutions near the C-terminus. J Bioenerg Biomembr 2009; 32:595-607. [PMID: 15254373 DOI: 10.1023/a:1005674628249] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We have sought to elucidate how the oligomycin sensitivity-conferring protein (OSCP) of the mitochondrial F(1)F(0)-ATP synthase (mtATPase) can influence proton channel function. Variants of OSCP, from the yeast Saccharomyces cerevisiae, having amino acid substitutions at a strictly conserved residue (Gly166) were expressed in place of normal OSCP. Cells expressing the OSCP variants were able to grow on nonfermentable substrates, albeit with some increase in generation time. Moreover, these strains exhibited increased sensitivity to oligomycin, suggestive of modification in functional interactions between the F(1) and F(0) sectors mediated by OSCP. Bioenergetic analysis of mitochondria from cells expressing OSCP variants indicated an increased respiratory rate under conditions of no net ATP synthesis. Using specific inhibitors of mtATPase, in conjunction with measurement of changes in mitochondrial transmembrane potential, it was revealed that this increased respiratory rate was a result of increased proton flux through the F(0) sector. This proton conductance, which is not coupled to phosphorylation, is exquisitely sensitive to inhibition by oligomycin. Nevertheless, the oxidative phosphorylation capacity of these mitochondria from cells expressing OSCP variants was no different to that of the control. These results suggest that the incorporation of OSCP variants into functional ATP synthase complexes can display effects in the control of proton flux through the F(0) sector, most likely mediated through altered protein-protein contacts within the enzyme complex. This conclusion is supported by data indicating impaired stability of solubilized mtATPase complexes that is not, however, reflected in the assembly of functional enzyme complexes in vivo. Given a location for OSCP atop the F(1)-alpha(3)beta(3) hexamer that is distant from the proton channel, then the modulation of proton flux by OSCP must occur "at a distance." We consider how subtle conformational changes in OSCP may be transmitted to F(0).
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Affiliation(s)
- G M Boyle
- Department of Biochemistry and Molecular Biology, PO Box 13D, Monash University, Victoria, 3800, Australia
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26
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Stuart RA. Supercomplex organization of the oxidative phosphorylation enzymes in yeast mitochondria. J Bioenerg Biomembr 2008; 40:411-7. [DOI: 10.1007/s10863-008-9168-4] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2008] [Accepted: 08/01/2008] [Indexed: 12/26/2022]
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Shen H, Walters DE, Mueller DM. Introduction of the chloroplast redox regulatory region in the yeast ATP synthase impairs cytochrome c oxidase. J Biol Chem 2008; 283:32937-43. [PMID: 18819926 DOI: 10.1074/jbc.m805310200] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The ATP synthase is under a number of mechanisms of regulation. The chloroplast ATPase has a unique mode of regulation in which activity is controlled by the redox state in the organelle. This mode of regulation is determined by a small unique region within the gamma-subunit and this region contains two cysteine residues. Introduction of this region within the yeast gamma-subunit causes a defect in oxidative phosphorylation. Oxidative phosphorylation is restored if the cysteine residues are replaced with serine. Biochemical analysis of the chimeric mitochondrial ATPase indicates that the ATP synthase is not largely altered with the cysteine residues in either the oxidized or reduced states. However, the level and activity of cytochrome c oxidase are decreased by about 90%, whereas that of NADH dehydrogenase and cytochrome c reductase are unchanged as compared with the wild-type enzymes. The level and activity of cytochrome c oxidase are restored with replacement of the cysteine residues with serine in the regulatory region. These results indicate that the chimeric ATP synthase containing cysteine, but not serine, decreases the expression or assembly of cytochrome c oxidase with little effect on the activity of the ATP synthase.
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Affiliation(s)
- Hong Shen
- Department of Biochemistry and Molecular Biology, Rosalind Franklin University of Medicine and Science, The Chicago Medical School, North Chicago, Illinois 60064, USA
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28
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Genova M, Baracca A, Biondi A, Casalena G, Faccioli M, Falasca A, Formiggini G, Sgarbi G, Solaini G, Lenaz G. Is supercomplex organization of the respiratory chain required for optimal electron transfer activity? BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2008; 1777:740-6. [DOI: 10.1016/j.bbabio.2008.04.007] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2007] [Revised: 03/31/2008] [Accepted: 04/05/2008] [Indexed: 02/03/2023]
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Saddar S, Dienhart MK, Stuart RA. The F1F0-ATP synthase complex influences the assembly state of the cytochrome bc1-cytochrome oxidase supercomplex and its association with the TIM23 machinery. J Biol Chem 2008; 283:6677-86. [PMID: 18187422 DOI: 10.1074/jbc.m708440200] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The enzyme complexes involved in mitochondrial oxidative phosphorylation are organized into higher ordered assemblies termed supercomplexes. Subunits e and g (Su e and Su g, respectively) are catalytically nonessential subunits of the F1F0-ATP synthase whose presence is required to directly support the stable dimerization of the ATP synthase complex. We report here that Su g and Su e are also important for securing the correct organizational state of the cytochrome bc1-cytochrome oxidase (COX) supercomplex. Mitochondria isolated from the Delta su e and Delta su g null mutant strains exhibit decreased levels of COX enzyme activity but appear to have normal COX subunit protein levels. An altered stoichiometry of the cytochrome bc1-COX supercomplex was observed in mitochondria deficient in Su e and/or Su g, and a perturbation in the association of Cox4, a catalytically important subunit of the COX complex, was also detected. In addition, an increase in the level of the TIM23 translocase associated with the cytochrome bc1-COX supercomplex is observed in the absence of Su e and Su g. Together, our data highlight that a further level of complexity exists between the oxidative phosphorylation supercomplexes, whereby the organizational state of one complex, i.e. the ATP synthase, may influence that of another supercomplex, namely the cytochrome bc1-COX complex.
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Affiliation(s)
- Sonika Saddar
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin 53233, USA
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30
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Devenish RJ, Prescott M, Rodgers AJW. The structure and function of mitochondrial F1F0-ATP synthases. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2008; 267:1-58. [PMID: 18544496 DOI: 10.1016/s1937-6448(08)00601-1] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We review recent advances in understanding of the structure of the F(1)F(0)-ATP synthase of the mitochondrial inner membrane (mtATPase). A significant achievement has been the determination of the structure of the principal peripheral or stator stalk components bringing us closer to achieving the Holy Grail of a complete 3D structure for the complex. A major focus of the field in recent years has been to understand the physiological significance of dimers or other oligomer forms of mtATPase recoverable from membranes and their relationship to the structure of the cristae of the inner mitochondrial membrane. In addition, the association of mtATPase with other membrane proteins has been described and suggests that further levels of functional organization need to be considered. Many reports in recent years have concerned the location and function of ATP synthase complexes or its component subunits on the external surface of the plasma membrane. We consider whether the evidence supports complete complexes being located on the cell surface, the biogenesis of such complexes, and aspects of function especially related to the structure of mtATPase.
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Affiliation(s)
- Rodney J Devenish
- Department of Biochemistry and Molecular Biology, and ARC Centre of Excellence in Microbial Structural and Functional Genomics, Monash University, Clayton Campus, Victoria, 3800, Australia
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31
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Hudder BN, Morales JG, Stubna A, Münck E, Hendrich MP, Lindahl PA. Electron paramagnetic resonance and Mössbauer spectroscopy of intact mitochondria from respiring Saccharomyces cerevisiae. J Biol Inorg Chem 2007; 12:1029-53. [PMID: 17665226 DOI: 10.1007/s00775-007-0275-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2007] [Accepted: 06/27/2007] [Indexed: 11/30/2022]
Abstract
Mitochondria from respiring cells were isolated under anaerobic conditions. Microscopic images were largely devoid of contaminants, and samples consumed O(2) in an NADH-dependent manner. Protein and metal concentrations of packed mitochondria were determined, as was the percentage of external void volume. Samples were similarly packed into electron paramagnetic resonance tubes, either in the as-isolated state or after exposure to various reagents. Analyses revealed two signals originating from species that could be removed by chelation, including rhombic Fe(3+) (g = 4.3) and aqueous Mn(2+) ions (g = 2.00 with Mn-based hyperfine). Three S = 5/2 signals from Fe(3+) hemes were observed, probably arising from cytochrome c peroxidase and the a(3):Cu(b) site of cytochrome c oxidase. Three Fe/S-based signals were observed, with averaged g values of 1.94, 1.90 and 2.01. These probably arise, respectively, from the [Fe(2)S(2)](+) cluster of succinate dehydrogenase, the [Fe(2)S(2)](+) cluster of the Rieske protein of cytochrome bc (1), and the [Fe(3)S(4)](+) cluster of aconitase, homoaconitase or succinate dehydrogenase. Also observed was a low-intensity isotropic g = 2.00 signal arising from organic-based radicals, and a broad signal with g (ave) = 2.02. Mössbauer spectra of intact mitochondria were dominated by signals from Fe(4)S(4) clusters (60-85% of Fe). The major feature in as-isolated samples, and in samples treated with ethylenebis(oxyethylenenitrilo)tetraacetic acid, dithionite or O(2), was a quadrupole doublet with DeltaE (Q) = 1.15 mm/s and delta = 0.45 mm/s, assigned to [Fe(4)S(4)](2+) clusters. Substantial high-spin non-heme Fe(2+) (up to 20%) and Fe(3+) (up to 15%) species were observed. The distribution of Fe was qualitatively similar to that suggested by the mitochondrial proteome.
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Affiliation(s)
- Brandon N Hudder
- Department of Chemistry, Texas A&M University, College Station, TX 77843-3255, USA
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32
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Bornhövd C, Vogel F, Neupert W, Reichert AS. Mitochondrial Membrane Potential Is Dependent on the Oligomeric State of F1F0-ATP Synthase Supracomplexes. J Biol Chem 2006; 281:13990-8. [PMID: 16551625 DOI: 10.1074/jbc.m512334200] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The F1F0-ATP synthase in mitochondria, in addition to its function in energy transduction, has a structural role in determining cristae morphology. This depends on its ability to form dimeric and higher oligomeric supracomplexes. Here we show that mutants of the dimer-specific subunits e and g, which destabilize dimeric and oligomeric F1F0-ATP synthase supracomplexes, have a decreased mitochondrial membrane potential delta psi. The degree of destabilization correlated with the reduction of the membrane potential. The enzymatic activities of F1F0-ATP synthase and cytochrome c oxidase, maximal respiration rate, coupling of oxidative phosphorylation, and tubular mitochondrial morphology were not affected or only to a minor extent. In mutants lacking one or two coiled-coil domains of subunit e, the reduction of the mitochondrial membrane potential was not due to loss of mitochondrial DNA, a reduced capacity of oxidative phosphorylation, or to altered cristae morphology. We propose a role for the supracomplexes of the F1F0-ATP synthase in organizing microdomains within the inner membrane, ensuring optimal bioenergetic competence of mitochondria.
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Affiliation(s)
- Carsten Bornhövd
- Adolf-Butenandt-Institut für Physiologische Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse 5, 81377 München, Germany
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33
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Gavin PD, Prescott M, Devenish RJ. F1F0-ATP synthase complex interactions in vivo can occur in the absence of the dimer specific subunit e. J Bioenerg Biomembr 2005; 37:55-66. [PMID: 15906150 DOI: 10.1007/s10863-005-4128-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2004] [Accepted: 03/02/2005] [Indexed: 10/25/2022]
Abstract
Evidence suggests membrane bound F(1)F(0)-ATPase complexes form stable associations such that dimers can be retrieved from detergent lysates of mitochondria isolated from a range of sources including algae, higher plants, yeast and bovine heart, and plant chloroplasts. The physiological relevance of these interactions is not clear but may be connected with the formation and structure of mitochondrial cristae. We sought to demonstrate, in vivo, the association of F(1)F(0)-ATPases in yeast cells co-expressing two b subunits each fused at its C-terminus to a GFP variant appropriate for fluorescence resonance energy transfer (FRET; BFP as the donor and GFP as the acceptor fluorophore). Both subunit b-GFP and b-BFP fusions were assembled into functional complexes. FRET was observed from enzyme complexes in molecular proximity in respiring cells providing the first demonstration of the association, in vivo, of F(1)F(0)-ATPase complexes. Moreover, FRET was observed within cells lacking the dimer specific subunit e, indicating structured associations can occur within the inner membrane in the absence of subunit e.
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Affiliation(s)
- Paul D Gavin
- Department of Biochemistry and Molecular Biology, and ARC Centre for Structural and Functional Microbial Genomics, Monash University, Clayton Campus, Victoria 3800, Australia
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34
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Everard-Gigot V, Dunn CD, Dolan BM, Brunner S, Jensen RE, Stuart RA. Functional analysis of subunit e of the F1Fo-ATP synthase of the yeast Saccharomyces cerevisiae: importance of the N-terminal membrane anchor region. EUKARYOTIC CELL 2005; 4:346-55. [PMID: 15701797 PMCID: PMC549337 DOI: 10.1128/ec.4.2.346-355.2005] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Mitochondrial F1Fo-ATP synthase complexes do not exist as physically independent entities but rather form dimeric and possibly oligomeric complexes in the inner mitochondrial membrane. Stable dimerization of two F1Fo-monomeric complexes involves the physical association of two membrane-embedded Fo-sectors. Previously, formation of the ATP synthase dimeric-oligomeric network was demonstrated to play a critical role in modulating the morphology of the mitochondrial inner membrane. In Saccharomyces cerevisiae, subunit e (Su e) of the Fo-sector plays a central role in supporting ATP synthase dimerization. The Su e protein is anchored to the inner membrane via a hydrophobic region located at its N-terminal end. The hydrophilic C-terminal region of Su e resides in the intermembrane space and contains a conserved coiled-coil motif. In the present study, we focused on characterizing the importance of these regions for the function of Su e. We created a number of C-terminal-truncated derivatives of the Su e protein and expressed them in the Su e null yeast mutant. Mitochondria were isolated from the resulting transformant strains, and a number of functions of Su e were analyzed. Our results indicate that the N-terminal hydrophobic region plays important roles in the Su e-dependent processes of mitochondrial DNA maintenance, modulation of mitochondrial morphology, and stabilization of the dimer-specific Fo subunits, subunits g and k. Furthermore, we show that the C-terminal coiled-coil region of Su e functions to stabilize the dimeric form of detergent-solubilized ATP synthase complexes. Finally, we propose a model to explain how Su e supports the assembly of the ATP synthase dimers-oligomers in the mitochondrial membrane.
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35
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Hong S, Pedersen PL. Mitochondrial ATP synthase: a bioinformatic approach reveals new insights about the roles of supernumerary subunits g and A6L. J Bioenerg Biomembr 2005; 36:515-23. [PMID: 15692730 DOI: 10.1007/s10863-004-8998-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The mitochondrial ATP synthase is a membrane protein complex which couples the proton gradient across the mitochondrial inner membrane to the synthesis of ATP from ADP+Pi. The complex is composed of essential subunits for its motor functions and supernumerary subunits, the roles of which remain to be elucidated. Subunits g and A6L are supernumerary subunits, and the specific roles of these subunits are still matters of debate. To gain insight into the functions of these two subunits, we carried out the alignment and the homolog search of the protein sequences of the subunits and found the following features: Subunit g appears to have isoforms in animals, and the transmembrane domain of the animal subunit g contains a completely conserved acidic residue in the middle of a helix on the conserved side of the transmembrane helix. This finding implicates the conserved acidic residue as important for the function of subunit g. The alignment of A6L protein sequences shows a conserved aromatic residue at the N-terminal domain with which the N-terminal MPQL sequence comprises a unique MPQLX4Ar motif that can signify the protein A6L. The conserved aromatic residue may also be important for the function of A6L.
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Affiliation(s)
- Sangjin Hong
- Department of Biological Chemistry, Johns Hopkins University, School of Medicine, 725 N. Wolfe Street, Baltimore, Maryland, 21205-2185, USA
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36
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Saddar S, Stuart RA. The yeast F(1)F(0)-ATP synthase: analysis of the molecular organization of subunit g and the importance of a conserved GXXXG motif. J Biol Chem 2005; 280:24435-42. [PMID: 15886192 DOI: 10.1074/jbc.m502804200] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The F(1)F(0)-ATP synthase enzyme is located in the inner mitochondrial membrane, where it forms dimeric complexes. Dimerization of the ATP synthase involves the physical association of the neighboring membrane-embedded F(0)-sectors. In yeast, the F(0)-sector subunits g and e (Su g and Su e, respectively) play a key role in supporting the formation of ATP synthase dimers. In this study we have focused on Su g to gain a better understanding of the function and the molecular organization of this subunit within the ATP synthase complex. Su g proteins contain a GXXXG motif (G is glycine, and X is any amino acid) in their single transmembrane segment. GXXXG can be a dimerization motif that supports helix-helix interactions between neighboring transmembrane segments. We demonstrate here that the GXXXG motif is important for the function and in particular for the stability of Su g within the ATP synthase. Using site-directed mutagenesis and cross-linking approaches, we demonstrate that Su g and Su e interact, and our findings emphasize the importance of the membrane anchor regions of these proteins for their interaction. Su e also contains a conserved GXXXG motif in its membrane anchor. However, data presented here would suggest that an intact GXXXG motif in Su g is not essential for the Su g-Su e interaction. We suggest that the GXXXG motif may not be the sole basis for a Su g-Su e interaction, and possibly these dimerization motifs may enable both Su g and Su e to interact with another mitochondrial protein.
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Affiliation(s)
- Sonika Saddar
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin 53233, USA
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John GB, Shang Y, Li L, Renken C, Mannella CA, Selker JML, Rangell L, Bennett MJ, Zha J. The mitochondrial inner membrane protein mitofilin controls cristae morphology. Mol Biol Cell 2005; 16:1543-54. [PMID: 15647377 PMCID: PMC551514 DOI: 10.1091/mbc.e04-08-0697] [Citation(s) in RCA: 359] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Mitochondria are complex organelles with a highly dynamic distribution and internal organization. Here, we demonstrate that mitofilin, a previously identified mitochondrial protein of unknown function, controls mitochondrial cristae morphology. Mitofilin is enriched in the narrow space between the inner boundary and the outer membranes, where it forms a homotypic interaction and assembles into a large multimeric protein complex. Down-regulation of mitofilin in HeLa cells by using specific small interfering RNA lead to decreased cellular proliferation and increased apoptosis, suggesting abnormal mitochondrial function. Although gross mitochondrial fission and fusion seemed normal, ultrastructural studies revealed disorganized mitochondrial inner membrane. Inner membranes failed to form tubular or vesicular cristae and showed as closely packed stacks of membrane sheets that fused intermittently, resulting in a complex maze of membranous network. Electron microscopic tomography estimated a substantial increase in inner:outer membrane ratio, whereas no cristae junctions were detected. In addition, mitochondria subsequently exhibited increased reactive oxygen species production and membrane potential. Although metabolic flux increased due to mitofilin deficiency, mitochondrial oxidative phosphorylation was not increased accordingly. We propose that mitofilin is a critical organizer of the mitochondrial cristae morphology and thus indispensable for normal mitochondrial function.
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Affiliation(s)
- George B John
- Department of Pathology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
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38
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Gavin PD, Prescott M, Luff SE, Devenish RJ. Cross-linking ATP synthase complexes in vivo eliminates mitochondrial cristae. J Cell Sci 2004; 117:2333-43. [PMID: 15126633 DOI: 10.1242/jcs.01074] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have used the tetrameric nature of the fluorescent protein DsRed to cross-link F1FO-ATPase complexes incorporating a subunit γ-DsRed fusion protein in vivo. Cells expressing such a fusion protein have impaired growth relative to control cells. Strikingly, fluorescence microscopy of these cells revealed aberrant mitochondrial morphology. Electron microscopy of cell sections revealed the absence of cristae and multiple layers of unfolded inner mitochondrial membrane. Complexes recovered from detergent lysates of mitochondria were present largely as tetramers. Co-expression of `free' DsRed targeted to the mitochondria reduced F1FO-ATPase oligomerisation and partially reversed the impaired growth and abnormal mitochondrial morphology. We conclude that the correct arrangement of F1FO-ATPase complexes within the mitochondrial inner membrane is crucial for the genesis and/or maintenance of mitochondrial cristae and morphology. Our findings further suggest that F1FO-ATPase can exist in oligomeric associations within the membrane during respiratory growth.
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Affiliation(s)
- Paul D Gavin
- Department of Biochemistry & Molecular Biology, and ARC Centre for Structural and Functional Microbial Genomics, Monash University, Clayton campus, Victoria 3800, Australia
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39
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Gavin PD, Devenish RJ, Prescott M. FRET reveals changes in the F1–stator stalk interaction during activity of F1F0-ATP synthase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2003; 1607:167-79. [PMID: 14670607 DOI: 10.1016/j.bbabio.2003.09.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A stator is proposed as necessary to prevent futile rotation of the F(1) catalytic sector of mitochondrial ATP synthase (mtATPase) during periods of ATP synthesis or ATP hydrolysis. Although the second stalk of mtATPase is generally believed to fulfil the role of a stator capable of withstanding the stress produced by rotation of the central rotor, there is little evidence to directly support this view. We show that interaction between two candidate proteins of the second stalk, OSCP and subunit b, fused at their C-termini to GFP variants and assembled into functional mtATPase can be monitored in mitochondria using fluorescence resonance energy transfer (FRET). Substitution of native OSCP with a variant containing a glycine 166 to asparagine (G166N) substitution yielded a metastable complex. In contrast to the enzyme containing native OSCP, FRET could be irreversibly lowered for the enzyme containing G166N at a rate that correlated closely with the rate of enzyme activity (ATP hydrolysis). The non-hydrolysable ATP analogue, AMP-PCP did not have this effect. We conclude that two candidate proteins of the stator stalk, OSCP and b, are subject to stresses during enzyme catalytic activity commensurate with their role as a part of a stator stalk.
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Affiliation(s)
- Paul D Gavin
- Department of Biochemistry and Molecular Biology, ARC Center for Structural and Functional Genomics, Monash University, Clayton Campus, Victoria 3800, Australia
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40
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Prescott M, Nowakowski S, Gavin P, Nagley P, Whisstock JC, Devenish RJ. Subunit gamma-green fluorescent protein fusions are functionally incorporated into mitochondrial F1F0-ATP synthase, arguing against a rigid cap structure at the top of F1. J Biol Chem 2003; 278:251-6. [PMID: 12414811 DOI: 10.1074/jbc.m204556200] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have investigated the question of the presence of a cap structure located at the top of the F(1) alpha(3)beta(3) hexamer of the yeast mitochondrial F(1)F(0)-ATP synthase complex. Specifically, we sought to determine whether the putative cap has a rigid structure and occludes the central shaft space formed by the alpha(3)beta(3) hexamer or alternatively whether the cap is more flexible permitting access to the central shaft space under certain conditions. Thus, we sought to establish whether subunit gamma, an essential component of the F(1) central stalk housed within the central shaft space and whose N and C termini would both lie beneath a putative cap, could be fused at its C terminus to green fluorescent protein (GFP) without loss of enzyme function. The GFP moiety serves to report on the integrity and location of fusion proteins containing different length polypeptide linkers between GFP and subunit gamma, as well as being a potential occluding structure in itself. Functional incorporation of subunit gamma-GFP fusions into ATP synthase of yeast cells lacking native subunit gamma was demonstrated by the ability of intact complexes to hydrolyze ATP and retain sensitivity to oligomycin. Our conclusion is that the putative cap structure cannot be an inflexible structure, but must be of a more flexible nature consistent with the accommodation of subunit gamma-GFP fusions within functional ATP synthase complexes.
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Affiliation(s)
- Mark Prescott
- Department of Biochemistry and Molecular Biology, P. O. Box 13D, Monash University, Clayton Campus, Victoria 3800, Australia
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41
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Paumard P, Arselin G, Vaillier J, Chaignepain S, Bathany K, Schmitter JM, Brèthes D, Velours J. Two ATP synthases can be linked through subunits i in the inner mitochondrial membrane of Saccharomyces cerevisiae. Biochemistry 2002; 41:10390-6. [PMID: 12173925 DOI: 10.1021/bi025923g] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cross-linking experiments showed that the supernumerary subunit i is close to the interface between two ATP synthases. These data were used to demonstrate the presence of ATP synthase dimers in the inner mitochondrial membrane of Saccharomyces cerevisiae. A cysteine residue was introduced into the inter-membrane space located C-terminal part of subunit i. Cross-linking experiments revealed a dimerization of subunit i. This cross-linking occurred only with the dimeric form of the enzyme after incubating intact mitochondria with a bis-maleimide reagent, thus indicating an inter-ATP synthase cross-linking, whereas the monomeric form of the enzyme exhibited only an intra-ATP synthase cross-linking with subunit 6, another component of the membranous domain of the ATP synthase.
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Affiliation(s)
- Patrick Paumard
- Institut de Biochimie et Génétique Cellulaires du CNRS, Université Victor Segalen, Bordeaux 2, 1 rue Camille Saint-Saëns 33077 Bordeaux Cedex, France
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42
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Soubannier V, Vaillier J, Paumard P, Coulary B, Schaeffer J, Velours J. In the absence of the first membrane-spanning segment of subunit 4(b), the yeast ATP synthase is functional but does not dimerize or oligomerize. J Biol Chem 2002; 277:10739-45. [PMID: 11799128 DOI: 10.1074/jbc.m111882200] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The N-terminal portion of the mitochondrial b-subunit is anchored in the inner mitochondrial membrane by two hydrophobic segments. We investigated the role of the first membrane-spanning segment, which is absent in prokaryotic and chloroplastic enzymes. In the absence of the first membrane-spanning segment of the yeast subunit (subunit 4), a strong decrease in the amount of subunit g was found. The mutant ATP synthase did not dimerize or oligomerize, and mutant cells displayed anomalous mitochondrial morphologies with onion-like structures. This phenotype is similar to that of the null mutant in the ATP20 gene that encodes subunit g, a component involved in the dimerization/oligomerization of ATP synthase. Our data indicate that the first membrane-spanning segment of the mitochondrial b-subunit is not essential for the function of the enzyme since its removal did not directly alter the oxidative phosphorylation. It is proposed that the unique membrane-spanning segment of subunit g and the first membrane-spanning segment of subunit 4 interact, as shown by cross-linking experiments. We hypothesize that in eukaryotic cells the b-subunit has evolved to accommodate the interaction with the g-subunit, an associated ATP synthase component only present in the mitochondrial enzyme.
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Affiliation(s)
- Vincent Soubannier
- Institut de Biochimie et Génétique Cellulaires du CNRS, Université Victor Segalen, Bordeaux 2, 1, rue Camille Saint Saëns, 33077 Bordeaux cedex, France
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43
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Paumard P, Vaillier J, Coulary B, Schaeffer J, Soubannier V, Mueller DM, Brèthes D, di Rago JP, Velours J. The ATP synthase is involved in generating mitochondrial cristae morphology. EMBO J 2002; 21:221-30. [PMID: 11823415 PMCID: PMC125827 DOI: 10.1093/emboj/21.3.221] [Citation(s) in RCA: 593] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The inner membrane of the mitochondrion folds inwards, forming the cristae. This folding allows a greater amount of membrane to be packed into the mitochondrion. The data in this study demonstrate that subunits e and g of the mitochondrial ATP synthase are involved in generating mitochondrial cristae morphology. These two subunits are non-essential components of ATP synthase and are required for the dimerization and oligomerization of ATP synthase. Mitochondria of yeast cells deficient in either subunits e or g were found to have numerous digitations and onion-like structures that correspond to an uncontrolled biogenesis and/or folding of the inner mitochondrial membrane. The present data show that there is a link between dimerization of the mitochondrial ATP synthase and cristae morphology. A model is proposed of the assembly of ATP synthase dimers, taking into account the oligomerization of the yeast enzyme and earlier data on the ultrastructure of mitochondrial cristae, which suggests that the association of ATP synthase dimers is involved in the control of the biogenesis of the inner mitochondrial membrane.
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Affiliation(s)
| | | | | | | | | | - David M. Mueller
- Institut de Biochimie et Génétique Cellulaires du CNRS, Université Victor Ségalen, Bordeaux 2, 1 rue Camille Saint Saëns, 33077 Bordeaux cedex, France and
Department of Biochemistry and Molecular Biology, The Chicago Medical School, 3333 Greenbay Road, North Chicago, IL 60064, USA Corresponding author e-mail:
| | | | | | - Jean Velours
- Institut de Biochimie et Génétique Cellulaires du CNRS, Université Victor Ségalen, Bordeaux 2, 1 rue Camille Saint Saëns, 33077 Bordeaux cedex, France and
Department of Biochemistry and Molecular Biology, The Chicago Medical School, 3333 Greenbay Road, North Chicago, IL 60064, USA Corresponding author e-mail:
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44
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Grandier-Vazeille X, Bathany K, Chaignepain S, Camougrand N, Manon S, Schmitter JM. Yeast mitochondrial dehydrogenases are associated in a supramolecular complex. Biochemistry 2001; 40:9758-69. [PMID: 11502169 DOI: 10.1021/bi010277r] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Separation of yeast mitochondrial complexes by colorless native polyacrylamide gel electrophoresis led to the identification of a supramolecular structure exhibiting NADH-dehydrogenase activity. Components of this complex were identified by N-terminal Edman degradation and matrix-assisted laser desorption ionization mass spectrometry. The complex was found to contain the five known intermembrane space-facing dehydrogenases, namely two external NADH-dehydrogenases Nde1p and Nde2p, glycerol-3-phosphate dehydrogenase Gut2p, D- and L-lactate-dehydrogenases Dld1p and Cyb2p, the matrix-facing NADH-dehydrogenase Ndi1p, two probable flavoproteins YOR356Wp and YPR004Cp, four tricarboxylic acids cycle enzymes (malate dehydrogenase Mdh1p, citrate synthase Cit1p, succinate dehydrogenase Sdh1p, and fumarate hydratase Fum1p), and the acetaldehyde dehydrogenase Ald4p. The association of these proteins is discussed in terms of NADH-channeling.
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Affiliation(s)
- X Grandier-Vazeille
- UMR5095 C.N.R.S./Université de Bordeaux 2, 1 rue Camille Saint-Saëns, 33077 Bordeaux Cedex, France.
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45
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Devenish RJ, Prescott M, Roucou X, Nagley P. Insights into ATP synthase assembly and function through the molecular genetic manipulation of subunits of the yeast mitochondrial enzyme complex. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1458:428-42. [PMID: 10838056 DOI: 10.1016/s0005-2728(00)00092-x] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Development of an increasingly detailed understanding of the eucaryotic mitochondrial ATP synthase requires a detailed knowledge of the stoichiometry, structure and function of F(0) sector subunits in the contexts of the proton channel and the stator stalk. Still to be resolved are the precise locations and roles of other supernumerary subunits present in mitochondrial ATP synthase complexes, but not found in the bacterial or chloroplast enzymes. The highly developed system of molecular genetic manipulation available in the yeast Saccharomyces cerevisiae, a unicellular eucaryote, permits testing for gene function based on the effects of gene disruption or deletion. In addition, the genes encoding ATP synthase subunits can be manipulated to introduce specific amino acids at desired positions within a subunit, or to add epitope or affinity tags at the C-terminus, enabling questions of stoichiometry, structure and function to be addressed. Newly emerging technologies, such as fusions of subunits with GFP are being applied to probe the dynamic interactions within mitochondrial ATP synthase, between ATP synthase complexes, and between ATP synthase and other mitochondrial enzyme complexes.
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Affiliation(s)
- R J Devenish
- Department of Biochemistry and Molecular Biology, Monash University, P.O. Box 13D, Vic. 3800, Australia
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46
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Paumard P, Vaillier J, Napias C, Arselin G, Brèthes D, Graves PV, Velours J. Environmental study of subunit i, a F(o) component of the yeast ATP synthase. Biochemistry 2000; 39:4199-205. [PMID: 10747812 DOI: 10.1021/bi992438l] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The topology of subunit i, a component of the yeast F(o)F(1)-ATP synthase, was determined by the use of cysteine-substituted mutants. The N(in)-C(out) orientation of this intrinsic subunit was confirmed by chemical modification of unique cysteine residues with 4-acetamido-4'-maleimidylstilbene-2,2'-disulfonic acid. Near-neighbor relationships between subunit i and subunits 6, f, g, and d were demonstrated by cross-link formation following sulfhydryl oxidation or reaction with homobifunctional and heterobifunctional reagents. Our data suggest interactions between the unique membrane-spanning segment of subunit i and the first transmembranous alpha-helix of subunit 6 and a stoichiometry of 1 subunit i per complex. Cross-linked products between mutant subunits i and proteins loosely bound to the F(o)F(1)-ATP synthase suggest that subunit i is located at the periphery of the enzyme and interacts with proteins of the inner mitochondrial membrane that are not involved in the structure of the yeast ATP synthase.
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Affiliation(s)
- P Paumard
- Institut de Biochimie et Génétique Cellulaires du CNRS, Université Victor Segalen, Bordeaux 2,1 rue Camille Saint-Saëns, 33077 Bordeaux Cedex, France
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47
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Abstract
Dynamic pictures of living genomes are now beginning to emerge from systematic studies of gene expression patterns using DNA microarrays. The rich information represented in the variation in each gene's expression provides the basis for a new kind of genomic map.
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Affiliation(s)
- T L Ferea
- Department of Genetics, L311, Stanford University School of Medicine, Stanford 94305-5120, USA.
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Ferea TL, Botstein D, Brown PO, Rosenzweig RF. Systematic changes in gene expression patterns following adaptive evolution in yeast. Proc Natl Acad Sci U S A 1999; 96:9721-6. [PMID: 10449761 PMCID: PMC22277 DOI: 10.1073/pnas.96.17.9721] [Citation(s) in RCA: 372] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Culturing a population of Saccharomyces cerevisiae for many generations under conditions to which it is not optimally adapted selects for fitter genetic variants. This simple experimental design provides a tractable model of adaptive evolution under natural selection. Beginning with a clonal, founding population, independently evolved strains were obtained from three independent cultures after continuous aerobic growth in glucose-limited chemostats for more than 250 generations. DNA microarrays were used to compare genome-wide patterns of gene expression in the evolved strains and the parental strain. Several hundred genes were found to have significantly altered expression in the evolved strains. Many of these genes showed similar alterations in their expression in all three evolved strains. Genes with altered expression in the three evolved strains included genes involved in glycolysis, the tricarboxylic acid cycle, oxidative phosphorylation, and metabolite transport. These results are consistent with physiological observations and indicate that increased fitness is acquired by altering regulation of central metabolism such that less glucose is fermented and more glucose is completely oxidized.
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Affiliation(s)
- T L Ferea
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305-5120, USA
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