1
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Prokopchuk G, Butenko A, Dacks JB, Speijer D, Field MC, Lukeš J. Lessons from the deep: mechanisms behind diversification of eukaryotic protein complexes. Biol Rev Camb Philos Soc 2023; 98:1910-1927. [PMID: 37336550 PMCID: PMC10952624 DOI: 10.1111/brv.12988] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 05/30/2023] [Accepted: 06/05/2023] [Indexed: 06/21/2023]
Abstract
Genetic variation is the major mechanism behind adaptation and evolutionary change. As most proteins operate through interactions with other proteins, changes in protein complex composition and subunit sequence provide potentially new functions. Comparative genomics can reveal expansions, losses and sequence divergence within protein-coding genes, but in silico analysis cannot detect subunit substitutions or replacements of entire protein complexes. Insights into these fundamental evolutionary processes require broad and extensive comparative analyses, from both in silico and experimental evidence. Here, we combine data from both approaches and consider the gamut of possible protein complex compositional changes that arise during evolution, citing examples of complete conservation to partial and total replacement by functional analogues. We focus in part on complexes in trypanosomes as they represent one of the better studied non-animal/non-fungal lineages, but extend insights across the eukaryotes by extensive comparative genomic analysis. We argue that gene loss plays an important role in diversification of protein complexes and hence enhancement of eukaryotic diversity.
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Affiliation(s)
- Galina Prokopchuk
- Institute of Parasitology, Biology Centre, Czech Academy of SciencesBranišovská 1160/31České Budějovice37005Czech Republic
- Faculty of ScienceUniversity of South BohemiaBranišovská 1160/31České Budějovice37005Czech Republic
| | - Anzhelika Butenko
- Institute of Parasitology, Biology Centre, Czech Academy of SciencesBranišovská 1160/31České Budějovice37005Czech Republic
- Faculty of ScienceUniversity of South BohemiaBranišovská 1160/31České Budějovice37005Czech Republic
- Life Science Research Centre, Faculty of ScienceUniversity of OstravaChittussiho 983/10Ostrava71000Czech Republic
| | - Joel B. Dacks
- Institute of Parasitology, Biology Centre, Czech Academy of SciencesBranišovská 1160/31České Budějovice37005Czech Republic
- Division of Infectious Diseases, Department of MedicineUniversity of Alberta1‐124 Clinical Sciences Building, 11350‐83 AvenueEdmontonT6G 2R3AlbertaCanada
- Centre for Life's Origins and Evolution, Department of Genetics, Evolution and the EnvironmentUniversity College LondonDarwin Building, Gower StreetLondonWC1E 6BTUK
| | - Dave Speijer
- Medical Biochemistry, Amsterdam UMCUniversity of AmsterdamMeibergdreef 15Amsterdam1105 AZThe Netherlands
| | - Mark C. Field
- Institute of Parasitology, Biology Centre, Czech Academy of SciencesBranišovská 1160/31České Budějovice37005Czech Republic
- School of Life SciencesUniversity of DundeeDow StreetDundeeDD1 5EHScotlandUK
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of SciencesBranišovská 1160/31České Budějovice37005Czech Republic
- Faculty of ScienceUniversity of South BohemiaBranišovská 1160/31České Budějovice37005Czech Republic
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2
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Abstract
Apicomplexan parasites constitute more than 6,000 species infecting a wide range of hosts. These include important pathogens such as those causing malaria and toxoplasmosis. Their evolutionary emergence coincided with the dawn of animals. Mitochondrial genomes of apicomplexan parasites have undergone dramatic reduction in their coding capacity, with genes for only three proteins and ribosomal RNA genes present in scrambled fragments originating from both strands. Different branches of the apicomplexans have undergone rearrangements of these genes, with Toxoplasma having massive variations in gene arrangements spread over multiple copies. The vast evolutionary distance between the parasite and the host mitochondria has been exploited for the development of antiparasitic drugs, especially those used to treat malaria, wherein inhibition of the parasite mitochondrial respiratory chain is selectively targeted with little toxicity to the host mitochondria. We describe additional unique characteristics of the parasite mitochondria that are being investigated and provide greater insights into these deep-branching eukaryotic pathogens.
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Affiliation(s)
- Ian M Lamb
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA;
| | - Ijeoma C Okoye
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA;
| | - Michael W Mather
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA;
| | - Akhil B Vaidya
- Center for Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA;
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3
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Han F, Hu Y, Wu M, He Z, Tian H, Zhou L. Structures of Tetrahymena thermophila respiratory megacomplexes on the tubular mitochondrial cristae. Nat Commun 2023; 14:2542. [PMID: 37248254 DOI: 10.1038/s41467-023-38158-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 04/19/2023] [Indexed: 05/31/2023] Open
Abstract
Tetrahymena thermophila, a classic ciliate model organism, has been shown to possess tubular mitochondrial cristae and highly divergent electron transport chain involving four transmembrane protein complexes (I-IV). Here we report cryo-EM structures of its ~8 MDa megacomplex IV2 + (I + III2 + II)2, as well as a ~ 10.6 MDa megacomplex (IV2 + I + III2 + II)2 at lower resolution. In megacomplex IV2 + (I + III2 + II)2, each CIV2 protomer associates one copy of supercomplex I + III2 and one copy of CII, forming a half ring-shaped architecture that adapts to the membrane curvature of mitochondrial cristae. Megacomplex (IV2 + I + III2 + II)2 defines the relative position between neighbouring half rings and maintains the proximity between CIV2 and CIII2 cytochrome c binding sites. Our findings expand the current understanding of divergence in eukaryotic electron transport chain organization and how it is related to mitochondrial morphology.
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Affiliation(s)
- Fangzhu Han
- Department of Biophysics, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, 310058, China
- Department of Critical Care Medicine of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, 310058, China
| | - Yiqi Hu
- Department of Biophysics, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, 310058, China
- Department of Critical Care Medicine of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, 310058, China
| | - Mengchen Wu
- Department of Biophysics, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, 310058, China
- Department of Critical Care Medicine of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, 310058, China
| | - Zhaoxiang He
- Department of Biophysics, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, 310058, China
- Department of Critical Care Medicine of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, 310058, China
| | - Hongtao Tian
- Department of Biophysics, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, 310058, China
- Department of Critical Care Medicine of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, 310058, China
| | - Long Zhou
- Department of Biophysics, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, 310058, China.
- Department of Critical Care Medicine of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, 310058, China.
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4
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Sinha SD, Wideman JG. The persistent homology of mitochondrial ATP synthases. iScience 2023; 26:106700. [PMID: 37250340 PMCID: PMC10214729 DOI: 10.1016/j.isci.2023.106700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 01/24/2023] [Accepted: 04/14/2023] [Indexed: 05/31/2023] Open
Abstract
Relatively little is known about ATP synthase structure in protists, and the investigated ones exhibit divergent structures distinct from yeast or animals. To clarify the subunit composition of ATP synthases across all eukaryotic lineages, we used homology detection techniques and molecular modeling tools to identify an ancestral set of 17 ATP synthase subunits. Most eukaryotes possess an ATP synthase comparable to those of animals and fungi, while some have undergone drastic divergence (e.g., ciliates, myzozoans, euglenozoans). Additionally, a ∼1 billion-year-old gene fusion between ATP synthase stator subunits was identified as a synapomorphy of the SAR (Stramenopila, Alveolata, Rhizaria) supergroup (stramenopile, alveolate, rhizaria). Our comparative approach highlights the persistence of ancestral subunits even amidst major structural changes. We conclude by urging that more ATP synthase structures (e.g., from jakobids, heteroloboseans, stramenopiles, rhizarians) are needed to provide a complete picture of the evolution of the structural diversity of this ancient and essential complex.
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Affiliation(s)
- Savar D. Sinha
- Center for Mechanisms of Evolution, Biodesign Institute, School of Life Sciences, Arizona State University, Tempe, AZ 85281, USA
| | - Jeremy G. Wideman
- Center for Mechanisms of Evolution, Biodesign Institute, School of Life Sciences, Arizona State University, Tempe, AZ 85281, USA
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5
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Mühleip A, Flygaard RK, Baradaran R, Haapanen O, Gruhl T, Tobiasson V, Maréchal A, Sharma V, Amunts A. Structural basis of mitochondrial membrane bending by the I-II-III 2-IV 2 supercomplex. Nature 2023; 615:934-938. [PMID: 36949187 PMCID: PMC10060162 DOI: 10.1038/s41586-023-05817-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 02/09/2023] [Indexed: 03/24/2023]
Abstract
Mitochondrial energy conversion requires an intricate architecture of the inner mitochondrial membrane1. Here we show that a supercomplex containing all four respiratory chain components contributes to membrane curvature induction in ciliates. We report cryo-electron microscopy and cryo-tomography structures of the supercomplex that comprises 150 different proteins and 311 bound lipids, forming a stable 5.8-MDa assembly. Owing to subunit acquisition and extension, complex I associates with a complex IV dimer, generating a wedge-shaped gap that serves as a binding site for complex II. Together with a tilted complex III dimer association, it results in a curved membrane region. Using molecular dynamics simulations, we demonstrate that the divergent supercomplex actively contributes to the membrane curvature induction and tubulation of cristae. Our findings highlight how the evolution of protein subunits of respiratory complexes has led to the I-II-III2-IV2 supercomplex that contributes to the shaping of the bioenergetic membrane, thereby enabling its functional specialization.
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Affiliation(s)
- Alexander Mühleip
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Solna, Sweden
- School of Infection and Immunity, University of Glasgow, Wellcome Centre for Integrative Parasitology, Glasgow, UK
| | - Rasmus Kock Flygaard
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Solna, Sweden
- Department of Molecular Biology and Genetics, Danish Research Institute of Translational Neuroscience-DANDRITE, Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus C, Denmark
| | - Rozbeh Baradaran
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Solna, Sweden
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Outi Haapanen
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Thomas Gruhl
- Institute of Structural and Molecular Biology, Birkbeck College, London, UK
| | - Victor Tobiasson
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Solna, Sweden
- MRC Laboratory of Molecular Biology, Cambridge, UK
- National Center for Biotechnology Information, National Library of Medicine, National Institute of Health, Bethesda, MD, USA
| | - Amandine Maréchal
- Institute of Structural and Molecular Biology, Birkbeck College, London, UK
- Institute of Structural and Molecular Biology, University College London, London, UK
| | - Vivek Sharma
- Department of Physics, University of Helsinki, Helsinki, Finland
- HiLIFE Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Alexey Amunts
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Solna, Sweden.
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6
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Lamb IM, Rios KT, Shukla A, Ahiya AI, Morrisey J, Mell JC, Lindner SE, Mather MW, Vaidya AB. Mitochondrially targeted proximity biotinylation and proteomic analysis in Plasmodium falciparum. PLoS One 2022; 17:e0273357. [PMID: 35984838 PMCID: PMC9390924 DOI: 10.1371/journal.pone.0273357] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 08/08/2022] [Indexed: 01/26/2023] Open
Abstract
Despite ongoing efforts to control malaria infection, progress in lowering the number of deaths and infections appears to have stalled. The continued high incidence of malaria infection and mortality is in part due to emergence of parasites resistant to frontline antimalarials. This highlights the need for continued identification of novel protein drug targets. Mitochondrial functions in Plasmodium falciparum, the deadliest species of human malaria parasite, are targets of validated antimalarials including atovaquone and proguanil (Malarone). Thus, there has been great interest in identifying other essential mitochondrial proteins as candidates for novel drug targets. Garnering an increased understanding of the proteomic landscape inside the P. falciparum mitochondrion will also allow us to learn about the basic biology housed within this unique organelle. We employed a proximity biotinylation technique and mass spectrometry to identify novel P. falciparum proteins putatively targeted to the mitochondrion. We fused the leader sequence of a mitochondrially targeted chaperone, Hsp60, to the promiscuous biotin ligase TurboID. Through these experiments, we generated a list of 122 "putative mitochondrial" proteins. To verify whether these proteins were indeed mitochondrial, we chose five candidate proteins of interest for localization studies using ectopic expression and tagging of each full-length protein. This allowed us to localize four candidate proteins of unknown function to the mitochondrion, three of which have previously been assessed to be essential. We suggest that phenotypic characterization of these and other proteins from this list of 122 could be fruitful in understanding the basic mitochondrial biology of these parasites and aid antimalarial drug discovery efforts.
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Affiliation(s)
- Ian M. Lamb
- Center for Molecular Parasitology, Institute for Molecular Medicine and Infectious Disease, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States of America
| | - Kelly T. Rios
- Department of Biochemistry and Molecular Biology, The Huck Center for Malaria Research, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Anurag Shukla
- Center for Molecular Parasitology, Institute for Molecular Medicine and Infectious Disease, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States of America
| | - Avantika I. Ahiya
- Center for Molecular Parasitology, Institute for Molecular Medicine and Infectious Disease, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States of America
| | - Joanne Morrisey
- Center for Molecular Parasitology, Institute for Molecular Medicine and Infectious Disease, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States of America
| | - Joshua C. Mell
- Center for Molecular Parasitology, Institute for Molecular Medicine and Infectious Disease, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States of America
| | - Scott E. Lindner
- Department of Biochemistry and Molecular Biology, The Huck Center for Malaria Research, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Michael W. Mather
- Center for Molecular Parasitology, Institute for Molecular Medicine and Infectious Disease, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States of America
| | - Akhil B. Vaidya
- Center for Molecular Parasitology, Institute for Molecular Medicine and Infectious Disease, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States of America
- * E-mail:
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7
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Miranda-Astudillo H, Ostolga-Chavarría M, Cardol P, González-Halphen D. Beyond being an energy supplier, ATP synthase is a sculptor of mitochondrial cristae. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2022; 1863:148569. [PMID: 35577152 DOI: 10.1016/j.bbabio.2022.148569] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 05/06/2022] [Accepted: 05/09/2022] [Indexed: 06/15/2023]
Abstract
Mitochondrial F1FO-ATP synthase plays a key role in cellular bioenergetics; this enzyme is present in all eukaryotic linages except in amitochondriate organisms. Despite its ancestral origin, traceable to the alpha proteobacterial endosymbiotic event, the actual structural diversity of these complexes, due to large differences in their polypeptide composition, reflects an important evolutionary divergence between eukaryotic lineages. We discuss the effect of these structural differences on the oligomerization of the complex and the shape of mitochondrial cristae.
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Affiliation(s)
- Héctor Miranda-Astudillo
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Marcos Ostolga-Chavarría
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Pierre Cardol
- InBios/Phytosystems, Institut de Botanique, Université de Liège, Liège, Belgium
| | - Diego González-Halphen
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico.
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8
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Zhou L, Maldonado M, Padavannil A, Guo F, Letts JA. Structures of Tetrahymena's respiratory chain reveal the diversity of eukaryotic core metabolism. Science 2022; 376:831-839. [PMID: 35357889 PMCID: PMC9169680 DOI: 10.1126/science.abn7747] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Respiration is a core biological energy-converting process whose last steps are carried out by a chain of multisubunit complexes in the inner mitochondrial membrane. To probe the functional and structural diversity of eukaryotic respiration, we examined the respiratory chain of the ciliate Tetrahymena thermophila (Tt). Using cryo-electron microscopy on a mixed sample, we solved structures of a supercomplex between Tt complex I (Tt-CI) and Tt-CIII2 (Tt-SC I+III2) and a structure of Tt-CIV2. Tt-SC I+III2 (~2.3 megadaltons) is a curved assembly with structural and functional symmetry breaking. Tt-CIV2 is a ~2.7-megadalton dimer with more than 50 subunits per protomer, including mitochondrial carriers and a TIM83-TIM133-like domain. Our structural and functional study of the T. thermophila respiratory chain reveals divergence in key components of eukaryotic respiration, thereby expanding our understanding of core metabolism.
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Affiliation(s)
- Long Zhou
- Department of Biophysics and Department of Critical Care Medicine of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - María Maldonado
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - Abhilash Padavannil
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - Fei Guo
- BIOEM Facility, University of California, Davis, CA 95616, USA
| | - James A. Letts
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
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9
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Dewar CE, Oeljeklaus S, Wenger C, Warscheid B, Schneider A. Characterization of a highly diverged mitochondrial ATP synthase F o subunit in Trypanosoma brucei. J Biol Chem 2022; 298:101829. [PMID: 35293314 PMCID: PMC9034290 DOI: 10.1016/j.jbc.2022.101829] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 03/02/2022] [Accepted: 03/04/2022] [Indexed: 11/24/2022] Open
Abstract
The mitochondrial F1Fo ATP synthase of the parasite Trypanosoma brucei has been previously studied in detail. This unusual enzyme switches direction in functionality during the life cycle of the parasite, acting as an ATP synthase in the insect stages, and as an ATPase to generate mitochondrial membrane potential in the mammalian bloodstream stages. Whereas the trypanosome F1 moiety is relatively highly conserved in structure and composition, the Fo subcomplex and the peripheral stalk have been shown to be more variable. Interestingly, a core subunit of the latter, the normally conserved subunit b, has been resistant to identification by sequence alignment or biochemical methods. Here, we identified a 17 kDa mitochondrial protein of the inner membrane, Tb927.8.3070, that is essential for normal growth, efficient oxidative phosphorylation, and membrane potential maintenance. Pull-down experiments and native PAGE analysis indicated that the protein is both associated with the F1Fo ATP synthase and integral to its assembly. In addition, its knockdown reduced the levels of Fo subunits, but not those of F1, and disturbed the cell cycle. Finally, analysis of structural homology using the HHpred algorithm showed that this protein has structural similarities to Fo subunit b of other species, indicating that this subunit may be a highly diverged form of the elusive subunit b.
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Affiliation(s)
- Caroline E Dewar
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
| | - Silke Oeljeklaus
- Department of Biochemistry, Theodor Boveri-Institute, University of Würzburg, Würzburg, Germany
| | - Christoph Wenger
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
| | - Bettina Warscheid
- Department of Biochemistry, Theodor Boveri-Institute, University of Würzburg, Würzburg, Germany; CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
| | - André Schneider
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland.
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10
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Miranda-Astudillo HV, Yadav KNS, Boekema EJ, Cardol P. Supramolecular associations between atypical oxidative phosphorylation complexes of Euglena gracilis. J Bioenerg Biomembr 2021; 53:351-363. [PMID: 33646522 PMCID: PMC8124061 DOI: 10.1007/s10863-021-09882-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 02/11/2021] [Indexed: 11/28/2022]
Abstract
In vivo associations of respiratory complexes forming higher supramolecular structures are generally accepted nowadays. Supercomplexes (SC) built by complexes I, III and IV and the so-called respirasome (I/III2/IV) have been described in mitochondria from several model organisms (yeasts, mammals and green plants), but information is scarce in other lineages. Here we studied the supramolecular associations between the complexes I, III, IV and V from the secondary photosynthetic flagellate Euglena gracilis with an approach that involves the extraction with several mild detergents followed by native electrophoresis. Despite the presence of atypical subunit composition and additional structural domains described in Euglena complexes I, IV and V, canonical associations into III2/IV, III2/IV2 SCs and I/III2/IV respirasome were observed together with two oligomeric forms of the ATP synthase (V2 and V4). Among them, III2/IV SC could be observed by electron microscopy. The respirasome was further purified by two-step liquid chromatography and showed in-vitro oxygen consumption independent of the addition of external cytochrome c.
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Affiliation(s)
- H V Miranda-Astudillo
- InBios/Phytosystems, Institut de Botanique, University of Liège, Liège, Belgium.
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico.
| | - K N S Yadav
- Department of Electron Microscopy, Groningen Biological Sciences and Biotechnology Institute, University of Groningen, Groningen, the Netherlands
- School of Biochemistry, University of Bristol, Bristol, BS8 1TD, UK
| | - E J Boekema
- Department of Electron Microscopy, Groningen Biological Sciences and Biotechnology Institute, University of Groningen, Groningen, the Netherlands
| | - P Cardol
- InBios/Phytosystems, Institut de Botanique, University of Liège, Liège, Belgium.
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11
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Hierro-Yap C, Šubrtová K, Gahura O, Panicucci B, Dewar C, Chinopoulos C, Schnaufer A, Zíková A. Bioenergetic consequences of F oF 1-ATP synthase/ATPase deficiency in two life cycle stages of Trypanosoma brucei. J Biol Chem 2021; 296:100357. [PMID: 33539923 PMCID: PMC7949148 DOI: 10.1016/j.jbc.2021.100357] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 12/23/2020] [Accepted: 01/28/2021] [Indexed: 12/17/2022] Open
Abstract
Mitochondrial ATP synthase is a reversible nanomotor synthesizing or hydrolyzing ATP depending on the potential across the membrane in which it is embedded. In the unicellular parasite Trypanosoma brucei, the direction of the complex depends on the life cycle stage of this digenetic parasite: in the midgut of the tsetse fly vector (procyclic form), the FoF1–ATP synthase generates ATP by oxidative phosphorylation, whereas in the mammalian bloodstream form, this complex hydrolyzes ATP and maintains mitochondrial membrane potential (ΔΨm). The trypanosome FoF1–ATP synthase contains numerous lineage-specific subunits whose roles remain unknown. Here, we seek to elucidate the function of the lineage-specific protein Tb1, the largest membrane-bound subunit. In procyclic form cells, Tb1 silencing resulted in a decrease of FoF1–ATP synthase monomers and dimers, rerouting of mitochondrial electron transfer to the alternative oxidase, reduced growth rate and cellular ATP levels, and elevated ΔΨm and total cellular reactive oxygen species levels. In bloodstream form parasites, RNAi silencing of Tb1 by ∼90% resulted in decreased FoF1–ATPase monomers and dimers, but it had no apparent effect on growth. The same findings were obtained by silencing of the oligomycin sensitivity-conferring protein, a conserved subunit in T. brucei FoF1–ATP synthase. However, as expected, nearly complete Tb1 or oligomycin sensitivity-conferring protein suppression was lethal because of the inability to sustain ΔΨm. The diminishment of FoF1–ATPase complexes was further accompanied by a decreased ADP/ATP ratio and reduced oxygen consumption via the alternative oxidase. Our data illuminate the often diametrically opposed bioenergetic consequences of FoF1–ATP synthase loss in insect versus mammalian forms of the parasite.
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Affiliation(s)
- Carolina Hierro-Yap
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Ceske Budejovice, Czech Republic; Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Karolína Šubrtová
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Ceske Budejovice, Czech Republic; Institute of Immunology and Infection Research, University of Edinburgh, United Kingdom
| | - Ondřej Gahura
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Ceske Budejovice, Czech Republic
| | - Brian Panicucci
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Ceske Budejovice, Czech Republic
| | - Caroline Dewar
- Institute of Immunology and Infection Research, University of Edinburgh, United Kingdom
| | | | - Achim Schnaufer
- Institute of Immunology and Infection Research, University of Edinburgh, United Kingdom
| | - Alena Zíková
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Ceske Budejovice, Czech Republic; Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic.
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12
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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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13
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Flygaard RK, Mühleip A, Tobiasson V, Amunts A. Type III ATP synthase is a symmetry-deviated dimer that induces membrane curvature through tetramerization. Nat Commun 2020; 11:5342. [PMID: 33093501 PMCID: PMC7583250 DOI: 10.1038/s41467-020-18993-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 09/24/2020] [Indexed: 01/01/2023] Open
Abstract
Mitochondrial ATP synthases form functional homodimers to induce cristae curvature that is a universal property of mitochondria. To expand on the understanding of this fundamental phenomenon, we characterized the unique type III mitochondrial ATP synthase in its dimeric and tetrameric form. The cryo-EM structure of a ciliate ATP synthase dimer reveals an unusual U-shaped assembly of 81 proteins, including a substoichiometrically bound ATPTT2, 40 lipids, and co-factors NAD and CoQ. A single copy of subunit ATPTT2 functions as a membrane anchor for the dimeric inhibitor IF1. Type III specific linker proteins stably tie the ATP synthase monomers in parallel to each other. The intricate dimer architecture is scaffolded by an extended subunit-a that provides a template for both intra- and inter-dimer interactions. The latter results in the formation of tetramer assemblies, the membrane part of which we determined to 3.1 Å resolution. The structure of the type III ATP synthase tetramer and its associated lipids suggests that it is the intact unit propagating the membrane curvature.
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Affiliation(s)
- Rasmus Kock Flygaard
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, 17165, Solna, Sweden
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, 17177, Stockholm, Sweden
| | - Alexander Mühleip
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, 17165, Solna, Sweden
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, 17177, Stockholm, Sweden
| | - Victor Tobiasson
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, 17165, Solna, Sweden
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, 17177, Stockholm, Sweden
| | - Alexey Amunts
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, 17165, Solna, Sweden.
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, 17177, Stockholm, Sweden.
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14
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Lewis WH, Lind AE, Sendra KM, Onsbring H, Williams TA, Esteban GF, Hirt RP, Ettema TJG, Embley TM. Convergent Evolution of Hydrogenosomes from Mitochondria by Gene Transfer and Loss. Mol Biol Evol 2020; 37:524-539. [PMID: 31647561 PMCID: PMC6993867 DOI: 10.1093/molbev/msz239] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Hydrogenosomes are H2-producing mitochondrial homologs found in some anaerobic microbial eukaryotes that provide a rare intracellular niche for H2-utilizing endosymbiotic archaea. Among ciliates, anaerobic and aerobic lineages are interspersed, demonstrating that the switch to an anaerobic lifestyle with hydrogenosomes has occurred repeatedly and independently. To investigate the molecular details of this transition, we generated genomic and transcriptomic data sets from anaerobic ciliates representing three distinct lineages. Our data demonstrate that hydrogenosomes have evolved from ancestral mitochondria in each case and reveal different degrees of independent mitochondrial genome and proteome reductive evolution, including the first example of complete mitochondrial genome loss in ciliates. Intriguingly, the FeFe-hydrogenase used for generating H2 has a unique domain structure among eukaryotes and appears to have been present, potentially through a single lateral gene transfer from an unknown donor, in the common aerobic ancestor of all three lineages. The early acquisition and retention of FeFe-hydrogenase helps to explain the facility whereby mitochondrial function can be so radically modified within this diverse and ecologically important group of microbial eukaryotes.
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Affiliation(s)
- William H Lewis
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle-Upon-Tyne, United Kingdom.,Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden.,Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen, The Netherlands
| | - Anders E Lind
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Kacper M Sendra
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle-Upon-Tyne, United Kingdom
| | - Henning Onsbring
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden.,Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen, The Netherlands
| | - Tom A Williams
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
| | - Genoveva F Esteban
- Department of Life and Environmental Sciences, Bournemouth University, Poole, United Kingdom
| | - Robert P Hirt
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle-Upon-Tyne, United Kingdom
| | - Thijs J G Ettema
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden.,Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen, The Netherlands
| | - T Martin Embley
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle-Upon-Tyne, United Kingdom
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15
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Johri P, Marinov GK, Doak TG, Lynch M. Population Genetics of Paramecium Mitochondrial Genomes: Recombination, Mutation Spectrum, and Efficacy of Selection. Genome Biol Evol 2019; 11:1398-1416. [PMID: 30980669 PMCID: PMC6505448 DOI: 10.1093/gbe/evz081] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/09/2019] [Indexed: 12/11/2022] Open
Abstract
The evolution of mitochondrial genomes and their population-genetic environment among unicellular eukaryotes are understudied. Ciliate mitochondrial genomes exhibit a unique combination of characteristics, including a linear organization and the presence of multiple genes with no known function or detectable homologs in other eukaryotes. Here we study the variation of ciliate mitochondrial genomes both within and across 13 highly diverged Paramecium species, including multiple species from the P. aurelia species complex, with four outgroup species: P. caudatum, P. multimicronucleatum, and two strains that may represent novel related species. We observe extraordinary conservation of gene order and protein-coding content in Paramecium mitochondria across species. In contrast, significant differences are observed in tRNA content and copy number, which is highly conserved in species belonging to the P. aurelia complex but variable among and even within the other Paramecium species. There is an increase in GC content from ∼20% to ∼40% on the branch leading to the P. aurelia complex. Patterns of polymorphism in population-genomic data and mutation-accumulation experiments suggest that the increase in GC content is primarily due to changes in the mutation spectra in the P. aurelia species. Finally, we find no evidence of recombination in Paramecium mitochondria and find that the mitochondrial genome appears to experience either similar or stronger efficacy of purifying selection than the nucleus.
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Affiliation(s)
- Parul Johri
- Department of Biology, Indiana University, Bloomington
| | - Georgi K Marinov
- Department of Biology, Indiana University, Bloomington.,Department of Genetics, Stanford University School of Medicine, Stanford, CA
| | - Thomas G Doak
- Department of Biology, Indiana University, Bloomington.,National Center for Genome Analysis Support, Indiana University, Bloomington
| | - Michael Lynch
- Department of Biology, Indiana University, Bloomington.,Center for Mechanisms of Evolution, School of Life Sciences, Arizona State University, Tempe
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16
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Huet D, Rajendran E, van Dooren GG, Lourido S. Identification of cryptic subunits from an apicomplexan ATP synthase. eLife 2018; 7:e38097. [PMID: 30204085 PMCID: PMC6133553 DOI: 10.7554/elife.38097] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 08/17/2018] [Indexed: 01/22/2023] Open
Abstract
The mitochondrial ATP synthase is a macromolecular motor that uses the proton gradient to generate ATP. Proper ATP synthase function requires a stator linking the catalytic and rotary portions of the complex. However, sequence-based searches fail to identify genes encoding stator subunits in apicomplexan parasites like Toxoplasma gondii or the related organisms that cause malaria. Here, we identify 11 previously unknown subunits from the Toxoplasma ATP synthase, which lack homologs outside the phylum. Modeling suggests that two of them, ICAP2 and ICAP18, are distantly related to mammalian stator subunits. Our analysis shows that both proteins form part of the ATP synthase complex. Depletion of ICAP2 leads to aberrant mitochondrial morphology, decreased oxygen consumption, and disassembly of the complex, consistent with its role as an essential component of the Toxoplasma ATP synthase. Our findings highlight divergent features of the central metabolic machinery in apicomplexans, which may reveal new therapeutic opportunities.
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Affiliation(s)
- Diego Huet
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
| | - Esther Rajendran
- Research School of BiologyAustralian National UniversityCanberraAustralia
| | - Giel G van Dooren
- Research School of BiologyAustralian National UniversityCanberraAustralia
| | - Sebastian Lourido
- Whitehead Institute for Biomedical ResearchCambridgeUnited States
- Department of BiologyMassachusetts Institute of TechnologyCambridgeMassachusetts, United States
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17
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Colina-Tenorio L, Dautant A, Miranda-Astudillo H, Giraud MF, González-Halphen D. The Peripheral Stalk of Rotary ATPases. Front Physiol 2018; 9:1243. [PMID: 30233414 PMCID: PMC6131620 DOI: 10.3389/fphys.2018.01243] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/16/2018] [Indexed: 12/18/2022] Open
Abstract
Rotary ATPases are a family of enzymes that are thought of as molecular nanomotors and are classified in three types: F, A, and V-type ATPases. Two members (F and A-type) can synthesize and hydrolyze ATP, depending on the energetic needs of the cell, while the V-type enzyme exhibits only a hydrolytic activity. The overall architecture of all these enzymes is conserved and three main sectors are distinguished: a catalytic core, a rotor and a stator or peripheral stalk. The peripheral stalks of the A and V-types are highly conserved in both structure and function, however, the F-type peripheral stalks have divergent structures. Furthermore, the peripheral stalk has other roles beyond its stator function, as evidenced by several biochemical and recent structural studies. This review describes the information regarding the organization of the peripheral stalk components of F, A, and V-ATPases, highlighting the key differences between the studied enzymes, as well as the different processes in which the structure is involved.
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Affiliation(s)
- Lilia Colina-Tenorio
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Alain Dautant
- CNRS, UMR5095, IBGC, Bordeaux, France.,Energy Transducing Systems and Mitochondrial Morphology, Université de Bordeaux, Bordeaux, France
| | - Héctor Miranda-Astudillo
- Genetics and Physiology of Microalgae, InBios, PhytoSYSTEMS, University of Liège, Liège, Belgium
| | - Marie-France Giraud
- CNRS, UMR5095, IBGC, Bordeaux, France.,Energy Transducing Systems and Mitochondrial Morphology, Université de Bordeaux, Bordeaux, France
| | - Diego González-Halphen
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
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18
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Salunke R, Mourier T, Banerjee M, Pain A, Shanmugam D. Highly diverged novel subunit composition of apicomplexan F-type ATP synthase identified from Toxoplasma gondii. PLoS Biol 2018; 16:e2006128. [PMID: 30005062 PMCID: PMC6059495 DOI: 10.1371/journal.pbio.2006128] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 07/25/2018] [Accepted: 06/22/2018] [Indexed: 12/18/2022] Open
Abstract
The mitochondrial F-type ATP synthase, a multisubunit nanomotor, is critical for maintaining cellular ATP levels. In T. gondii and other apicomplexan parasites, many subunit components necessary for proper assembly and functioning of this enzyme appear to be missing. Here, we report the identification of 20 novel subunits of T. gondii F-type ATP synthase from mass spectrometry analysis of partially purified monomeric (approximately 600 kDa) and dimeric (>1 MDa) forms of the enzyme. Despite extreme sequence diversification, key FO subunits a, b, and d can be identified from conserved structural features. Orthologs for these proteins are restricted to apicomplexan, chromerid, and dinoflagellate species. Interestingly, their absence in ciliates indicates a major diversion, with respect to subunit composition of this enzyme, within the alveolate clade. Discovery of these highly diversified novel components of the apicomplexan F-type ATP synthase complex could facilitate the development of novel antiparasitic agents. Structural and functional characterization of this unusual enzyme complex will advance our fundamental understanding of energy metabolism in apicomplexan species.
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Affiliation(s)
- Rahul Salunke
- Biochemical Sciences Division, CSIR-National Chemical Laboratory, Pune, Maharashtra, India
| | - Tobias Mourier
- Pathogen Genomics Laboratory, BESE Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Manidipa Banerjee
- Kusuma School of Biological Sciences, Indian Institute of Technology-Delhi, Hauz Khas, New Delhi, India
| | - Arnab Pain
- Pathogen Genomics Laboratory, BESE Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Dhanasekaran Shanmugam
- Biochemical Sciences Division, CSIR-National Chemical Laboratory, Pune, Maharashtra, India
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19
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Miranda-Astudillo H, Colina-Tenorio L, Jiménez-Suárez A, Vázquez-Acevedo M, Salin B, Giraud MF, Remacle C, Cardol P, González-Halphen D. Oxidative phosphorylation supercomplexes and respirasome reconstitution of the colorless alga Polytomella sp. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018. [PMID: 29540299 DOI: 10.1016/j.bbabio.2018.03.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The proposal that the respiratory complexes can associate with each other in larger structures named supercomplexes (SC) is generally accepted. In the last decades most of the data about this association came from studies in yeasts, mammals and plants, and information is scarce in other lineages. Here we studied the supramolecular association of the F1FO-ATP synthase (complex V) and the respiratory complexes I, III and IV of the colorless alga Polytomella sp. with an approach that involves solubilization using mild detergents, n-dodecyl-β-D-maltoside (DDM) or digitonin, followed by separation of native protein complexes by electrophoresis (BN-PAGE), after which we identified oligomeric forms of complex V (mainly V2 and V4) and different respiratory supercomplexes (I/IV6, I/III4, I/IV). In addition, purification/reconstitution of the supercomplexes by anion exchange chromatography was also performed. The data show that these complexes have the ability to strongly associate with each other and form DDM-stable macromolecular structures. The stable V4 ATPase oligomer was observed by electron-microscopy and the association of the respiratory complexes in the so-called "respirasome" was able to perform in-vitro oxygen consumption.
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Affiliation(s)
- Héctor Miranda-Astudillo
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico; Genetics and Physiology of microalgae, InBioS/Phytosystems, University of Liège, Belgium.
| | - Lilia Colina-Tenorio
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico
| | - Alejandra Jiménez-Suárez
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico
| | - Miriam Vázquez-Acevedo
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico
| | - Bénédicte Salin
- CNRS, UMR5095, IBGC, 1 rue Camille Saint-Saëns, 33077 Bordeaux, France; Université de Bordeaux, Campus Carreire, 146 Rue Léo Saignat, 33077 Bordeaux, France
| | - Marie-France Giraud
- CNRS, UMR5095, IBGC, 1 rue Camille Saint-Saëns, 33077 Bordeaux, France; Université de Bordeaux, Campus Carreire, 146 Rue Léo Saignat, 33077 Bordeaux, France
| | - Claire Remacle
- Genetics and Physiology of microalgae, InBioS/Phytosystems, University of Liège, Belgium
| | - Pierre Cardol
- Genetics and Physiology of microalgae, InBioS/Phytosystems, University of Liège, Belgium
| | - Diego González-Halphen
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico
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20
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ATP synthase from Trypanosoma brucei has an elaborated canonical F 1-domain and conventional catalytic sites. Proc Natl Acad Sci U S A 2018; 115:2102-2107. [PMID: 29440423 DOI: 10.1073/pnas.1720940115] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The structures and functions of the components of ATP synthases, especially those subunits involved directly in the catalytic formation of ATP, are widely conserved in metazoans, fungi, eubacteria, and plant chloroplasts. On the basis of a map at 32.5-Å resolution determined in situ in the mitochondria of Trypanosoma brucei by electron cryotomography, it has been proposed that the ATP synthase in this species has a noncanonical structure and different catalytic sites in which the catalytically essential arginine finger is provided not by the α-subunit adjacent to the catalytic nucleotide-binding site as in all species investigated to date, but rather by a protein, p18, found only in the euglenozoa. A crystal structure at 3.2-Å resolution of the catalytic domain of the same enzyme demonstrates that this proposal is incorrect. In many respects, the structure is similar to the structures of F1-ATPases determined previously. The α3β3-spherical portion of the catalytic domain in which the three catalytic sites are found, plus the central stalk, are highly conserved, and the arginine finger is provided conventionally by the α-subunits adjacent to each of the three catalytic sites found in the β-subunits. Thus, the enzyme has a conventional catalytic mechanism. The structure differs from previous described structures by the presence of a p18 subunit, identified only in the euglenozoa, associated with the external surface of each of the three α-subunits, thereby elaborating the F1-domain. Subunit p18 is a pentatricopeptide repeat (PPR) protein with three PPRs and appears to have no function in the catalytic mechanism of the enzyme.
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21
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Gahura O, Šubrtová K, Váchová H, Panicucci B, Fearnley IM, Harbour ME, Walker JE, Zíková A. The F 1 -ATPase from Trypanosoma brucei is elaborated by three copies of an additional p18-subunit. FEBS J 2017; 285:614-628. [PMID: 29247468 DOI: 10.1111/febs.14364] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 11/16/2017] [Accepted: 12/08/2017] [Indexed: 01/09/2023]
Abstract
The F-ATPases (also called the F1 Fo -ATPases or ATP synthases) are multi-subunit membrane-bound molecular machines that produce ATP in bacteria and in eukaryotic mitochondria and chloroplasts. The structures and enzymic mechanisms of their F1 -catalytic domains are highly conserved in all species investigated hitherto. However, there is evidence that the F-ATPases from the group of protozoa known as Euglenozoa have novel features. Therefore, we have isolated pure and active F1 -ATPase from the euglenozoan parasite, Trypanosoma brucei, and characterized it. All of the usual eukaryotic subunits (α, β, γ, δ, and ε) were present in the enzyme, and, in addition, two unique features were detected. First, each of the three α-subunits in the F1 -domain has been cleaved by proteolysis in vivo at two sites eight residues apart, producing two assembled fragments. Second, the T. brucei F1 -ATPase has an additional subunit, called p18, present in three copies per complex. Suppression of expression of p18 affected in vitro growth of both the insect and infectious mammalian forms of T. brucei. It also reduced the levels of monomeric and multimeric F-ATPase complexes and diminished the in vivo hydrolytic activity of the enzyme significantly. These observations imply that p18 plays a role in the assembly of the F1 domain. These unique features of the F1 -ATPase extend the list of special characteristics of the F-ATPase from T. brucei, and also, demonstrate that the architecture of the F1 -ATPase complex is not strictly conserved in eukaryotes.
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Affiliation(s)
- Ondřej Gahura
- Institute of Parasitology, Biology Centre, Czech Academy of Science, České Budějovice, Czech Republic.,The Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - Karolína Šubrtová
- Institute of Parasitology, Biology Centre, Czech Academy of Science, České Budějovice, Czech Republic
| | - Hana Váchová
- Institute of Parasitology, Biology Centre, Czech Academy of Science, České Budějovice, Czech Republic
| | - Brian Panicucci
- Institute of Parasitology, Biology Centre, Czech Academy of Science, České Budějovice, Czech Republic
| | - Ian M Fearnley
- The Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - Michael E Harbour
- The Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - John E Walker
- The Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK
| | - Alena Zíková
- Institute of Parasitology, Biology Centre, Czech Academy of Science, České Budějovice, Czech Republic.,Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
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22
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+Targeting Mitochondrial Functions as Antimalarial Regime, What Is Next? CURRENT CLINICAL MICROBIOLOGY REPORTS 2017. [DOI: 10.1007/s40588-017-0075-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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23
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Sánchez-Vásquez L, Vázquez-Acevedo M, de la Mora J, Vega-deLuna F, Cardol P, Remacle C, Dreyfus G, González-Halphen D. Near-neighbor interactions of the membrane-embedded subunits of the mitochondrial ATP synthase of a chlorophycean alga. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:497-509. [DOI: 10.1016/j.bbabio.2017.04.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 04/25/2017] [Accepted: 04/29/2017] [Indexed: 12/24/2022]
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24
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Sánchez-Vásquez L, González-Halphen D. TOPOLOGÍA Y FUNCIÓN DE LAS SUBUNIDADES INTRÍNSECAS DE LA MEMBRANA DE LAS F 1 F O -ATP SINTASA MITOCONDRIALES. TIP REVISTA ESPECIALIZADA EN CIENCIAS QUÍMICO-BIOLÓGICAS 2017. [DOI: 10.1016/j.recqb.2017.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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25
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Yadav KS, Miranda-Astudillo HV, Colina-Tenorio L, Bouillenne F, Degand H, Morsomme P, González-Halphen D, Boekema EJ, Cardol P. Atypical composition and structure of the mitochondrial dimeric ATP synthase from Euglena gracilis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:267-275. [DOI: 10.1016/j.bbabio.2017.01.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 12/22/2016] [Accepted: 01/10/2017] [Indexed: 11/26/2022]
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Sawyer EM, Brunner EC, Hwang Y, Ivey LE, Brown O, Bannon M, Akrobetu D, Sheaffer KE, Morgan O, Field CO, Suresh N, Gordon MG, Gunnell ET, Regruto LA, Wood CG, Fuller MT, Hales KG. Testis-specific ATP synthase peripheral stalk subunits required for tissue-specific mitochondrial morphogenesis in Drosophila. BMC Cell Biol 2017; 18:16. [PMID: 28335714 PMCID: PMC5364652 DOI: 10.1186/s12860-017-0132-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 03/15/2017] [Indexed: 12/13/2022] Open
Abstract
Background In Drosophila early post-meiotic spermatids, mitochondria undergo dramatic shaping into the Nebenkern, a spherical body with complex internal structure that contains two interwrapped giant mitochondrial derivatives. The purpose of this study was to elucidate genetic and molecular mechanisms underlying the shaping of this structure. Results The knotted onions (knon) gene encodes an unconventionally large testis-specific paralog of ATP synthase subunit d and is required for internal structure of the Nebenkern as well as its subsequent disassembly and elongation. Knon localizes to spermatid mitochondria and, when exogenously expressed in flight muscle, alters the ratio of ATP synthase complex dimers to monomers. By RNAi knockdown we uncovered mitochondrial shaping roles for other testis-expressed ATP synthase subunits. Conclusions We demonstrate the first known instance of a tissue-specific ATP synthase subunit affecting tissue-specific mitochondrial morphogenesis. Since ATP synthase dimerization is known to affect the degree of inner mitochondrial membrane curvature in other systems, the effect of Knon and other testis-specific paralogs of ATP synthase subunits may be to mediate differential membrane curvature within the Nebenkern.
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Affiliation(s)
- Eric M Sawyer
- Department of Biology, Davidson College, Davidson, NC, USA
| | | | - Yihharn Hwang
- Department of Biology, Davidson College, Davidson, NC, USA
| | - Lauren E Ivey
- Department of Biology, Davidson College, Davidson, NC, USA
| | - Olivia Brown
- Department of Biology, Davidson College, Davidson, NC, USA
| | - Megan Bannon
- Department of Biology, Davidson College, Davidson, NC, USA
| | | | | | - Oshauna Morgan
- Department of Biology, Davidson College, Davidson, NC, USA
| | - Conroy O Field
- Department of Biology, Davidson College, Davidson, NC, USA
| | - Nishita Suresh
- Department of Biology, Davidson College, Davidson, NC, USA
| | - M Grace Gordon
- Department of Biology, Davidson College, Davidson, NC, USA
| | | | | | - Cricket G Wood
- Departments of Developmental Biology and Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Margaret T Fuller
- Departments of Developmental Biology and Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Karen G Hales
- Department of Biology, Davidson College, Davidson, NC, USA. .,Departments of Developmental Biology and Genetics, Stanford University School of Medicine, Stanford, CA, USA.
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In situ structure of trypanosomal ATP synthase dimer reveals a unique arrangement of catalytic subunits. Proc Natl Acad Sci U S A 2017; 114:992-997. [PMID: 28096380 DOI: 10.1073/pnas.1612386114] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
We used electron cryotomography and subtomogram averaging to determine the in situ structures of mitochondrial ATP synthase dimers from two organisms belonging to the phylum euglenozoa: Trypanosoma brucei, a lethal human parasite, and Euglena gracilis, a photosynthetic protist. At a resolution of 32.5 Å and 27.5 Å, respectively, the two structures clearly exhibit a noncanonical F1 head, in which the catalytic (αβ)3 assembly forms a triangular pyramid rather than the pseudo-sixfold ring arrangement typical of all other ATP synthases investigated so far. Fitting of known X-ray structures reveals that this unusual geometry results from a phylum-specific cleavage of the α subunit, in which the C-terminal αC fragments are displaced by ∼20 Å and rotated by ∼30° from their expected positions. In this location, the αC fragment is unable to form the conserved catalytic interface that was thought to be essential for ATP synthesis, and cannot convert γ-subunit rotation into the conformational changes implicit in rotary catalysis. The new arrangement of catalytic subunits suggests that the mechanism of ATP generation by rotary ATPases is less strictly conserved than has been generally assumed. The ATP synthases of these organisms present a unique model system for discerning the individual contributions of the α and β subunits to the fundamental process of ATP synthesis.
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Helical arrays of U-shaped ATP synthase dimers form tubular cristae in ciliate mitochondria. Proc Natl Acad Sci U S A 2016; 113:8442-7. [PMID: 27402755 DOI: 10.1073/pnas.1525430113] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
F1Fo-ATP synthases are universal energy-converting membrane protein complexes that synthesize ATP from ADP and inorganic phosphate. In mitochondria of yeast and mammals, the ATP synthase forms V-shaped dimers, which assemble into rows along the highly curved ridges of lamellar cristae. Using electron cryotomography and subtomogram averaging, we have determined the in situ structure and organization of the mitochondrial ATP synthase dimer of the ciliate Paramecium tetraurelia. The ATP synthase forms U-shaped dimers with parallel monomers. Each complex has a prominent intracrista domain, which links the c-ring of one monomer to the peripheral stalk of the other. Close interaction of intracrista domains in adjacent dimers results in the formation of helical ATP synthase dimer arrays, which differ from the loose dimer rows in all other organisms observed so far. The parameters of the helical arrays match those of the cristae tubes, suggesting the unique features of the P. tetraurelia ATP synthase are directly responsible for generating the helical tubular cristae. We conclude that despite major structural differences between ATP synthase dimers of ciliates and other eukaryotes, the formation of ATP synthase dimer rows is a universal feature of mitochondria and a fundamental determinant of cristae morphology.
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Vargas-Caballero M, Willaime-Morawek S, Gomez-Nicola D, Perry VH, Bulters D, Mudher A. The use of human neurons for novel drug discovery in dementia research. Expert Opin Drug Discov 2016; 11:355-67. [PMID: 26878555 DOI: 10.1517/17460441.2016.1154528] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Although many disease models exist for neurodegenerative disease, the translation of basic research findings to clinic is very limited. Studies using freshly resected human brain tissue, commonly discarded from neurosurgical procedures, should complement on-going work using stem cell-derived human neurons and glia thus increasing the likelihood of success in clinical trials. AREAS COVERED Herein, the authors discuss key issues in the lack of translation from basic research to clinic. They also review the evidence that human neurons, both freshly resected brain tissue and stem cell-derived neurons, such as induced pluripotent stem cells (iPSCs), can be used for analysis of physiological and molecular mechanisms in health and disease. Furthermore, the authors compare and contrast studies using live human brain tissue and studies using induced human stem cell-derived neuron models. Using an example from the area of neurodegeneration, the authors suggest that replicating elements of research findings from animals and stem cell models in resected human brain tissue would strengthen our understanding of disease mechanisms and the therapeutic strategies and aid translation. EXPERT OPINION The use of human brain tissue alongside iPSC-derived neural models can validate molecular mechanisms identified in rodent disease models and strengthen their relevance to humans. If drug target engagement and mechanism of cellular action can be validated in human brain tissue, this will increase the success rate in clinical research. The combined use of resected human brain tissue, alongside iPSC-derived neural models, could be considered a standard step in pre-clinical research and help to bridge the gap to clinical trials.
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Affiliation(s)
- Mariana Vargas-Caballero
- a Centre for Biological Sciences , University of Southampton , Southampton , UK.,b Institute for Life Sciences , University of Southampton , Southampton , UK
| | - Sandrine Willaime-Morawek
- c Clinical Neurosciences and Psychiatry, Faculty of Medicine and Centre for Human Development, Stem Cells and Regeneration , University of Southampton , Southampton , UK
| | - Diego Gomez-Nicola
- a Centre for Biological Sciences , University of Southampton , Southampton , UK
| | - V Hugh Perry
- a Centre for Biological Sciences , University of Southampton , Southampton , UK
| | - Diederik Bulters
- d Wessex Neurological Centre , Southampton General Hospital , Southampton , UK
| | - Amrit Mudher
- a Centre for Biological Sciences , University of Southampton , Southampton , UK
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Vázquez-Acevedo M, Vega-deLuna F, Sánchez-Vásquez L, Colina-Tenorio L, Remacle C, Cardol P, Miranda-Astudillo H, González-Halphen D. Dissecting the peripheral stalk of the mitochondrial ATP synthase of chlorophycean algae. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1183-1190. [PMID: 26873638 DOI: 10.1016/j.bbabio.2016.02.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 01/25/2016] [Accepted: 02/05/2016] [Indexed: 12/13/2022]
Abstract
The algae Chlamydomonas reinhardtii and Polytomella sp., a green and a colorless member of the chlorophycean lineage respectively, exhibit a highly-stable dimeric mitochondrial F1Fo-ATP synthase (complex V), with a molecular mass of 1600 kDa. Polytomella, lacking both chloroplasts and a cell wall, has greatly facilitated the purification of the algal ATP-synthase. Each monomer of the enzyme has 17 polypeptides, eight of which are the conserved, main functional components, and nine polypeptides (Asa1 to Asa9) unique to chlorophycean algae. These atypical subunits form the two robust peripheral stalks observed in the highly-stable dimer of the algal ATP synthase in several electron-microscopy studies. The topological disposition of the components of the enzyme has been addressed with cross-linking experiments in the isolated complex; generation of subcomplexes by limited dissociation of complex V; detection of subunit-subunit interactions using recombinant subunits; in vitro reconstitution of subcomplexes; silencing of the expression of Asa subunits; and modeling of the overall structural features of the complex by EM image reconstruction. Here, we report that the amphipathic polymer Amphipol A8-35 partially dissociates the enzyme, giving rise to two discrete dimeric subcomplexes, whose compositions were characterized. An updated model for the topological disposition of the 17 polypeptides that constitute the algal enzyme is suggested. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi.
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Affiliation(s)
- Miriam Vázquez-Acevedo
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., Mexico
| | - Félix Vega-deLuna
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., Mexico
| | - Lorenzo Sánchez-Vásquez
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., Mexico
| | - Lilia Colina-Tenorio
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., Mexico
| | - Claire Remacle
- Genetics and Physiology of Microalgae, Department of Life Sciences, University of Liège, B-4000 Liège, Belgium
| | - Pierre Cardol
- Genetics and Physiology of Microalgae, Department of Life Sciences, University of Liège, B-4000 Liège, Belgium
| | - Héctor Miranda-Astudillo
- Genetics and Physiology of Microalgae, Department of Life Sciences, University of Liège, B-4000 Liège, Belgium
| | - Diego González-Halphen
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., Mexico.
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Mosaic nature of the mitochondrial proteome: Implications for the origin and evolution of mitochondria. Proc Natl Acad Sci U S A 2015; 112:10133-8. [PMID: 25848019 DOI: 10.1073/pnas.1421379112] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Comparative studies of the mitochondrial proteome have identified a conserved core of proteins descended from the α-proteobacterial endosymbiont that gave rise to the mitochondrion and was the source of the mitochondrial genome in contemporary eukaryotes. A surprising result of phylogenetic analyses is the relatively small proportion (10-20%) of the mitochondrial proteome displaying a clear α-proteobacterial ancestry. A large fraction of mitochondrial proteins typically has detectable homologs only in other eukaryotes and is presumed to represent proteins that emerged specifically within eukaryotes. A further significant fraction of the mitochondrial proteome consists of proteins with homologs in prokaryotes, but without a robust phylogenetic signal affiliating them with specific prokaryotic lineages. The presumptive evolutionary source of these proteins is quite different in contending models of mitochondrial origin.
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Towards structural and functional characterization of photosynthetic and mitochondrial supercomplexes. Micron 2015; 72:39-51. [PMID: 25841081 DOI: 10.1016/j.micron.2015.03.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 01/23/2015] [Accepted: 03/04/2015] [Indexed: 11/23/2022]
Abstract
Bioenergetic reactions in chloroplasts and mitochondria are catalyzed by large multi-subunit membrane proteins. About two decades ago it became clear that several of these large membrane proteins further associate into supercomplexes and since then a number of new ones have been described. In this review we focus on supercomplexes involved in light harvesting and electron transfer in the primary reactions of oxygenic photosynthesis and on the mitochondrial supercomplexes that catalyze electron transfer and ATP synthesis in oxidative phosphorylation. Functional and structural aspects are overviewed. In addition, several relevant technical aspects are discussed, including membrane solubilization with suitable detergents and methods of purification. Some open questions are addressed, such as the lack of high-resolution structures, the outstanding gaps in the knowledge about supercomplexes involved in cyclic electron transport in photosynthesis and the unusual mitochondrial protein complexes of protists and in particular of ciliates.
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Šubrtová K, Panicucci B, Zíková A. ATPaseTb2, a unique membrane-bound FoF1-ATPase component, is essential in bloodstream and dyskinetoplastic trypanosomes. PLoS Pathog 2015; 11:e1004660. [PMID: 25714685 PMCID: PMC4340940 DOI: 10.1371/journal.ppat.1004660] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 01/06/2015] [Indexed: 12/21/2022] Open
Abstract
In the infectious stage of Trypanosoma brucei, an important parasite of humans and livestock, the mitochondrial (mt) membrane potential (Δψm) is uniquely maintained by the ATP hydrolytic activity and subsequent proton pumping of the essential FoF1-ATPase. Intriguingly, this multiprotein complex contains several trypanosome-specific subunits of unknown function. Here, we demonstrate that one of the largest novel subunits, ATPaseTb2, is membrane-bound and localizes with monomeric and multimeric assemblies of the FoF1-ATPase. Moreover, RNAi silencing of ATPaseTb2 quickly leads to a significant decrease of the Δψm that manifests as a decreased growth phenotype, indicating that the FoF1-ATPase is impaired. To further explore the function of this protein, we employed a trypanosoma strain that lacks mtDNA (dyskinetoplastic, Dk) and thus subunit a, an essential component of the proton pore in the membrane Fo-moiety. These Dk cells generate the Δψm by combining the hydrolytic activity of the matrix-facing F1-ATPase and the electrogenic exchange of ATP4- for ADP3- by the ATP/ADP carrier (AAC). Surprisingly, in addition to the expected presence of F1-ATPase, the monomeric and multimeric FoF1-ATPase complexes were identified. In fact, the immunoprecipitation of a F1-ATPase subunit demonstrated that ATPaseTb2 was a component of these complexes. Furthermore, RNAi studies established that the membrane-bound ATPaseTb2 subunit is essential for maintaining normal growth and the Δψm of Dk cells. Thus, even in the absence of subunit a, a portion of the FoF1-ATPase is assembled in Dk cells.
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Affiliation(s)
- Karolína Šubrtová
- Institute of Parasitology, Biology Centre, CAS, České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Brian Panicucci
- Institute of Parasitology, Biology Centre, CAS, České Budějovice, Czech Republic
| | - Alena Zíková
- Institute of Parasitology, Biology Centre, CAS, České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
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The ADP/ATP carrier and its relationship to oxidative phosphorylation in ancestral protist trypanosoma brucei. EUKARYOTIC CELL 2015; 14:297-310. [PMID: 25616281 DOI: 10.1128/ec.00238-14] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The highly conserved ADP/ATP carrier (AAC) is a key energetic link between the mitochondrial (mt) and cytosolic compartments of all aerobic eukaryotic cells, as it exchanges the ATP generated inside the organelle for the cytosolic ADP. Trypanosoma brucei, a parasitic protist of medical and veterinary importance, possesses a single functional AAC protein (TbAAC) that is related to the human and yeast ADP/ATP carriers. However, unlike previous studies performed with these model organisms, this study showed that TbAAC is most likely not a stable component of either the respiratory supercomplex III+IV or the ATP synthasome but rather functions as a physically separate entity in this highly diverged eukaryote. Therefore, TbAAC RNA interference (RNAi) ablation in the insect stage of T. brucei does not impair the activity or arrangement of the respiratory chain complexes. Nevertheless, RNAi silencing of TbAAC caused a severe growth defect that coincides with a significant reduction of mt ATP synthesis by both substrate and oxidative phosphorylation. Furthermore, TbAAC downregulation resulted in a decreased level of cytosolic ATP, a higher mt membrane potential, an elevated amount of reactive oxygen species, and a reduced consumption of oxygen in the mitochondria. Interestingly, while TbAAC has previously been demonstrated to serve as the sole ADP/ATP carrier for ADP influx into the mitochondria, our data suggest that a second carrier for ATP influx may be present and active in the T. brucei mitochondrion. Overall, this study provides more insight into the delicate balance of the functional relationship between TbAAC and the oxidative phosphorylation (OXPHOS) pathway in an early diverged eukaryote.
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35
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Kumar U, Saier MH. Comparative Genomic Analysis of Integral Membrane Transport Proteins in Ciliates. J Eukaryot Microbiol 2014; 62:167-87. [DOI: 10.1111/jeu.12156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 04/23/2014] [Accepted: 04/28/2014] [Indexed: 11/25/2022]
Affiliation(s)
- Ujjwal Kumar
- Division of Biological Sciences; University of California at San Diego; La Jolla California
| | - Milton H. Saier
- Division of Biological Sciences; University of California at San Diego; La Jolla California
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Abstract
All aspects of biological diversification ultimately trace to evolutionary modifications at the cellular level. This central role of cells frames the basic questions as to how cells work and how cells come to be the way they are. Although these two lines of inquiry lie respectively within the traditional provenance of cell biology and evolutionary biology, a comprehensive synthesis of evolutionary and cell-biological thinking is lacking. We define evolutionary cell biology as the fusion of these two eponymous fields with the theoretical and quantitative branches of biochemistry, biophysics, and population genetics. The key goals are to develop a mechanistic understanding of general evolutionary processes, while specifically infusing cell biology with an evolutionary perspective. The full development of this interdisciplinary field has the potential to solve numerous problems in diverse areas of biology, including the degree to which selection, effectively neutral processes, historical contingencies, and/or constraints at the chemical and biophysical levels dictate patterns of variation for intracellular features. These problems can now be examined at both the within- and among-species levels, with single-cell methodologies even allowing quantification of variation within genotypes. Some results from this emerging field have already had a substantial impact on cell biology, and future findings will significantly influence applications in agriculture, medicine, environmental science, and synthetic biology.
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The mitochondrial respiratory chain of the secondary green alga Euglena gracilis shares many additional subunits with parasitic Trypanosomatidae. Mitochondrion 2014; 19 Pt B:338-49. [DOI: 10.1016/j.mito.2014.02.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 02/06/2014] [Accepted: 02/07/2014] [Indexed: 11/17/2022]
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Chaban Y, Boekema EJ, Dudkina NV. Structures of mitochondrial oxidative phosphorylation supercomplexes and mechanisms for their stabilisation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:418-26. [DOI: 10.1016/j.bbabio.2013.10.004] [Citation(s) in RCA: 200] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2013] [Revised: 10/01/2013] [Accepted: 10/15/2013] [Indexed: 01/13/2023]
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Respiratory Chain Supercomplexes in Mitochondria. THE STRUCTURAL BASIS OF BIOLOGICAL ENERGY GENERATION 2014. [DOI: 10.1007/978-94-017-8742-0_12] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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41
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Miranda-Astudillo H, Cano-Estrada A, Vázquez-Acevedo M, Colina-Tenorio L, Downie-Velasco A, Cardol P, Remacle C, Domínguez-Ramírez L, González-Halphen D. Interactions of subunits Asa2, Asa4 and Asa7 in the peripheral stalk of the mitochondrial ATP synthase of the chlorophycean alga Polytomella sp. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1837:1-13. [PMID: 23933283 DOI: 10.1016/j.bbabio.2013.08.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 07/24/2013] [Accepted: 08/02/2013] [Indexed: 12/29/2022]
Abstract
Mitochondrial F1FO-ATP synthase of chlorophycean algae is a complex partially embedded in the inner mitochondrial membrane that is isolated as a highly stable dimer of 1600kDa. It comprises 17 polypeptides, nine of which (subunits Asa1 to 9) are not present in classical mitochondrial ATP synthases and appear to be exclusive of the chlorophycean lineage. In particular, subunits Asa2, Asa4 and Asa7 seem to constitute a section of the peripheral stalk of the enzyme. Here, we over-expressed and purified subunits Asa2, Asa4 and Asa7 and the corresponding amino-terminal and carboxy-terminal halves of Asa4 and Asa7 in order to explore their interactions in vitro, using immunochemical techniques, blue native electrophoresis and affinity chromatography. Asa4 and Asa7 interact strongly, mainly through their carboxy-terminal halves. Asa2 interacts with both Asa7 and Asa4, and also with subunit α in the F1 sector. The three Asa proteins form an Asa2/Asa4/Asa7 subcomplex. The entire Asa7 and the carboxy-terminal half of Asa4 seem to be instrumental in the interaction with Asa2. Based on these results and on computer-generated structural models of the three subunits, we propose a model for the Asa2/Asa4/Asa7 subcomplex and for its disposition in the peripheral stalk of the algal ATP synthase.
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Xiong J, Lu Y, Feng J, Yuan D, Tian M, Chang Y, Fu C, Wang G, Zeng H, Miao W. Tetrahymena functional genomics database (TetraFGD): an integrated resource for Tetrahymena functional genomics. DATABASE-THE JOURNAL OF BIOLOGICAL DATABASES AND CURATION 2013; 2013:bat008. [PMID: 23482072 PMCID: PMC3594985 DOI: 10.1093/database/bat008] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
The ciliated protozoan Tetrahymena thermophila is a useful unicellular model organism for studies of eukaryotic cellular and molecular biology. Researches on T. thermophila have contributed to a series of remarkable basic biological principles. After the macronuclear genome was sequenced, substantial progress has been made in functional genomics research on T. thermophila, including genome-wide microarray analysis of the T. thermophila life cycle, a T. thermophila gene network analysis based on the microarray data and transcriptome analysis by deep RNA sequencing. To meet the growing demands for the Tetrahymena research community, we integrated these data to provide a public access database: Tetrahymena functional genomics database (TetraFGD). TetraFGD contains three major resources, including the RNA-Seq transcriptome, microarray and gene networks. The RNA-Seq data define gene structures and transcriptome, with special emphasis on exon-intron boundaries; the microarray data describe gene expression of 20 time points during three major stages of the T. thermophila life cycle; the gene network data identify potential gene-gene interactions of 15 049 genes. The TetraFGD provides user-friendly search functions that assist researchers in accessing gene models, transcripts, gene expression data and gene-gene relationships. In conclusion, the TetraFGD is an important functional genomic resource for researchers who focus on the Tetrahymena or other ciliates. Database URL: http://tfgd.ihb.ac.cn/
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Affiliation(s)
- Jie Xiong
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
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Chung HS, Wang SB, Venkatraman V, Murray CI, Van Eyk JE. Cysteine oxidative posttranslational modifications: emerging regulation in the cardiovascular system. Circ Res 2013; 112:382-92. [PMID: 23329793 PMCID: PMC4340704 DOI: 10.1161/circresaha.112.268680] [Citation(s) in RCA: 206] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2012] [Accepted: 10/05/2012] [Indexed: 12/22/2022]
Abstract
In the cardiovascular system, changes in oxidative balance can affect many aspects of cellular physiology through redox-signaling. Depending on the magnitude, fluctuations in the cell's production of reactive oxygen and nitrogen species can regulate normal metabolic processes, activate protective mechanisms, or be cytotoxic. Reactive oxygen and nitrogen species can have many effects including the posttranslational modification of proteins at critical cysteine thiols. A subset can act as redox-switches, which elicit functional effects in response to changes in oxidative state. Although the general concepts of redox-signaling have been established, the identity and function of many regulatory switches remains unclear. Characterizing the effects of individual modifications is the key to understand how the cell interprets oxidative signals under physiological and pathological conditions. Here, we review the various cysteine oxidative posttranslational modifications and their ability to function as redox-switches that regulate the cell's response to oxidative stimuli. In addition, we discuss how these modifications have the potential to influence other posttranslational modifications' signaling pathways though cross-talk. Finally, we review the increasing number of tools being developed to identify and quantify the various cysteine oxidative posttranslational modifications and how this will advance our understanding of redox-regulation.
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Affiliation(s)
- Heaseung S Chung
- Department of Biological Chemistry, Johns Hopkins University, Baltimore, MD 21224, USA
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Butterfield ER, Howe CJ, Nisbet RER. An analysis of dinoflagellate metabolism using EST data. Protist 2012; 164:218-36. [PMID: 23085481 DOI: 10.1016/j.protis.2012.09.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 09/10/2012] [Accepted: 09/10/2012] [Indexed: 01/03/2023]
Abstract
The dinoflagellates are an important group of eukaryotic, single celled algae. They are the sister group of the Apicomplexa, a group of intracellular parasites and photosynthetic algae including the malaria parasite Plasmodium. Many apicomplexan mitochondria have a number of unusual features, including the lack of a pyruvate dehydrogenase and the existence of a branched TCA cycle. Here, we analyse dinoflagellate EST (expressed sequence tag) data to determine whether these features are apicomplexan-specific, or if they are more widespread. We show that dinoflagellates have replaced a key subunit (E1) of pyruvate dehydrogenase with a subunit of bacterial origin and that transcripts encoding many of the proteins that are essential in a conventional ATP synthase/Complex V are absent, as is the case in Apicomplexa. There is a pathway for synthesis of starch or glycogen as a storage carbohydrate. Transcripts encoding isocitrate lyase and malate synthase are present, consistent with ultrastructural reports of a glyoxysome. Finally, evidence for a conventional haem biosynthesis pathway is found, in contrast to the Apicomplexa, Chromera and early branching dinoflagellates (Perkinsus, Oxyrrhis).
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Affiliation(s)
- Erin R Butterfield
- Sansom Institute for Health Research, University of South Australia, North Terrace, Adelaide, SA 5000, Australia
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Abstract
Viewed through the lens of the genome it contains, the mitochondrion is of unquestioned bacterial ancestry, originating from within the bacterial phylum α-Proteobacteria (Alphaproteobacteria). Accordingly, the endosymbiont hypothesis--the idea that the mitochondrion evolved from a bacterial progenitor via symbiosis within an essentially eukaryotic host cell--has assumed the status of a theory. Yet mitochondrial genome evolution has taken radically different pathways in diverse eukaryotic lineages, and the organelle itself is increasingly viewed as a genetic and functional mosaic, with the bulk of the mitochondrial proteome having an evolutionary origin outside Alphaproteobacteria. New data continue to reshape our views regarding mitochondrial evolution, particularly raising the question of whether the mitochondrion originated after the eukaryotic cell arose, as assumed in the classical endosymbiont hypothesis, or whether this organelle had its beginning at the same time as the cell containing it.
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Huynen MA, Duarte I, Szklarczyk R. Loss, replacement and gain of proteins at the origin of the mitochondria. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1827:224-31. [PMID: 22902511 DOI: 10.1016/j.bbabio.2012.08.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 07/19/2012] [Accepted: 08/05/2012] [Indexed: 01/28/2023]
Abstract
We review what has been inferred about the changes at the level of the proteome that accompanied the evolution of the mitochondrion from an alphaproteobacterium. We regard these changes from an alphaproteobacterial perspective: which proteins were lost during mitochondrial evolution? And, of the proteins that were lost, which ones have been replaced by other, non-orthologous proteins with a similar function? Combining literature-supported replacements with quantitative analyses of mitochondrial proteomics data we infer that most of the loss and replacements that separate current day mitochondria in mammals from alphaproteobacteria took place before the radiation of the eukaryotes. Recent analyses show that also the acquisition of new proteins to the large protein complexes of the oxidative phosphorylation and the mitochondrial ribosome occurred mainly before the divergence of the eukaryotes. These results indicate a significant number of pivotal evolutionary events between the acquisition of the endosymbiont and the radiation of the eukaryotes and therewith support an early acquisition of mitochondria in eukaryotic evolution. Technically, advancements in the reconstruction of the evolutionary trajectories of loss, replacement and gain of mitochondrial proteins depend on using profile-based homology detection methods for sequence analysis. We highlight the mitochondrial Holliday junction resolvase endonuclease, for which such methods have detected new "family members" and in which function differentiation is accompanied by the loss of catalytic residues for the original enzymatic function and the gain of a protein domain for the new function. This article is part of a Special Issue entitled: The evolutionary aspects of bioenergetic systems.
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Affiliation(s)
- Martijn A Huynen
- Centre for Molecular and Biomolecular Informatics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6400 HB Nijmegen, The Netherlands.
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Disparate phenotypic effects from the knockdown of various Trypanosoma brucei cytochrome c oxidase subunits. Mol Biochem Parasitol 2012; 184:90-8. [PMID: 22569586 DOI: 10.1016/j.molbiopara.2012.04.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Revised: 04/27/2012] [Accepted: 04/28/2012] [Indexed: 10/28/2022]
Abstract
The Trypanosoma brucei cytochrome c oxidase (respiratory complex IV) is a very divergent complex containing a surprisingly high number of trypanosomatid-specific subunits with unknown function. To gain insight into the functional organization of this large protein complex, the expression of three novel subunits (TbCOX VII, TbCOX X and TbCOX 6080) were down-regulated by RNA interference. We demonstrate that all three subunits are important for the proper function of complex IV and the growth of the procyclic stage of T. brucei. These phenotypes were manifested by the structural instability of the complex when these indispensible subunits were repressed. Furthermore, the impairment of cytochrome c oxidase resulted in other severe mitochondrial phenotypes, such as a decreased mitochondrial membrane potential, reduced ATP production via oxidative phoshorylation and redirection of oxygen consumption to the trypanosome-specific alternative oxidase, TAO. Interestingly, the inspected subunits revealed some disparate phenotypes, particularly regarding the activity of cytochrome c reductase (respiratory complex III). While the activity of complex III was down-regulated in RNAi induced cells for TbCOX X and TbCOX 6080, the TbCOX VII silenced cell line actually exhibited higher levels of complex III activity and elevated levels of ROS formation. This result suggests that the examined subunits may have different functional roles within complex IV of T. brucei, perhaps involving the ability to communicate between sequential enzymes in the respiratory chain. In summary, by characterizing the function of three hypothetical components of complex IV, we are able to assign these proteins as genuine and indispensable subunits of the procyclic T. brucei cytochrome c oxidase, an essential component of the respiratory chain in these evolutionary ancestral and medically important parasites.
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Wloga D, Frankel J. From Molecules to Morphology: Cellular Organization of Tetrahymena thermophila. Methods Cell Biol 2012; 109:83-140. [DOI: 10.1016/b978-0-12-385967-9.00005-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Abstract
Within the past decade, genomic studies have emerged as essential and highly productive tools to explore the biology of Tetrahymena thermophila. The current major resources, which have been extensively mined by the research community, are the annotated macronuclear genome assembly, transcriptomic data and the databases that house this information. Efforts in progress will soon improve these data sources and expand their scope, including providing annotated micronuclear and comparative genomic sequences. Future studies of Tetrahymena cell and molecular biology, development, physiology, evolution and ecology will benefit greatly from these resources and the advanced genomic technologies they enable.
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Conservation and innovation in Tetrahymena membrane traffic: proteins, lipids, and compartments. Methods Cell Biol 2012; 109:141-75. [PMID: 22444145 DOI: 10.1016/b978-0-12-385967-9.00006-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The past decade has seen a significant expansion in our understanding of membrane traffic in Tetrahymena thermophila, facilitated by the development of new experimental tools and by the availability of the macronuclear genome sequence. Here we review studies on multiple pathways of uptake and secretion, as well as work on metabolism of membrane lipids. We discuss evidence for conservation versus innovation in the mechanisms used in ciliates compared with those in other eukaryotic lineages, and raise the possibility that existing gene expression databases can be exploited to analyze specific pathways of membrane traffic in these cells.
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