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Zítek J, King MS, Peña-Diaz P, Pyrihová E, King AC, Kunji ERS, Hampl V. The free-living flagellate Paratrimastix pyriformis uses a distinct mitochondrial carrier to balance adenine nucleotide pools. Arch Biochem Biophys 2023; 742:109638. [PMID: 37192692 PMCID: PMC10251735 DOI: 10.1016/j.abb.2023.109638] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 05/12/2023] [Accepted: 05/13/2023] [Indexed: 05/18/2023]
Abstract
Paratrimastix pyriformis is a free-living flagellate thriving in low-oxygen freshwater sediments. It belongs to the group Metamonada along with human parasites, such as Giardia and Trichomonas. Like other metamonads, P. pyriformis has a mitochondrion-related organelle (MRO) which in this protist is primarily involved in one-carbon folate metabolism. The MRO contains four members of the solute carrier family 25 (SLC25) responsible for the exchange of metabolites across the mitochondrial inner membrane. Here, we characterise the function of the adenine nucleotide carrier PpMC1 by thermostability shift and transport assays. We show that it transports ATP, ADP and, to a lesser extent, AMP, but not phosphate. The carrier is distinct in function and origin from both ADP/ATP carriers and ATP-Mg/phosphate carriers, and it most likely represents a distinct class of adenine nucleotide carriers.
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Affiliation(s)
- Justyna Zítek
- Charles University, Faculty of Science, Department of Parasitology, BIOCEV, Vestec, 252 50, Czech Republic
| | - Martin S King
- Medical Research Council Mitochondrial Biology Unit, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, United Kingdom
| | - Priscila Peña-Diaz
- Charles University, Faculty of Science, Department of Parasitology, BIOCEV, Vestec, 252 50, Czech Republic
| | - Eva Pyrihová
- Medical Research Council Mitochondrial Biology Unit, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, United Kingdom; University of Stavanger, Department of Chemistry, Bioscience, And Environmental Engineering, Richard Johnsens Gate 4, N-4021, Stavanger, Norway
| | - Alannah C King
- Medical Research Council Mitochondrial Biology Unit, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, United Kingdom
| | - Edmund R S Kunji
- Medical Research Council Mitochondrial Biology Unit, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, United Kingdom.
| | - Vladimír Hampl
- Charles University, Faculty of Science, Department of Parasitology, BIOCEV, Vestec, 252 50, Czech Republic.
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2
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He L, Tronstad KJ, Maheshwari A. Mitochondrial Dynamics during Development. NEWBORN (CLARKSVILLE, MD.) 2023; 2:19-44. [PMID: 37206581 PMCID: PMC10193651 DOI: 10.5005/jp-journals-11002-0053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Mitochondria are dynamic membrane-bound organelles in eukaryotic cells. These are important for the generation of chemical energy needed to power various cellular functions and also support metabolic, energetic, and epigenetic regulation in various cells. These organelles are also important for communication with the nucleus and other cellular structures, to maintain developmental sequences and somatic homeostasis, and for cellular adaptation to stress. Increasing information shows mitochondrial defects as an important cause of inherited disorders in different organ systems. In this article, we provide an extensive review of ontogeny, ultrastructural morphology, biogenesis, functional dynamics, important clinical manifestations of mitochondrial dysfunction, and possibilities for clinical intervention. We present information from our own clinical and laboratory research in conjunction with information collected from an extensive search in the databases PubMed, EMBASE, and Scopus.
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Affiliation(s)
- Ling He
- Department of Pediatrics and Pharmacology, Johns Hopkins University, Baltimore, United States of America
| | | | - Akhil Maheshwari
- Founding Chairman, Global Newborn Society, Clarksville, Maryland, United States of America
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3
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Stabel M, Schweitzer T, Haack K, Gorenflo P, Aliyu H, Ochsenreither K. Isolation and Biochemical Characterization of Six Anaerobic Fungal Strains from Zoo Animal Feces. Microorganisms 2021; 9:1655. [PMID: 34442734 PMCID: PMC8399178 DOI: 10.3390/microorganisms9081655] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 11/30/2022] Open
Abstract
Anaerobic fungi are prime candidates for the conversion of agricultural waste products to biofuels. Despite the increasing interest in these organisms, their growth requirements and metabolism remain largely unknown. The isolation of five strains of anaerobic fungi and their identification as Neocallimastix cameroonii, Caecomyces spec., Orpinomyces joyonii, Pecoramyces ruminantium, and Khoyollomyces ramosus, is described. The phylogeny supports the reassignment of Neocallimastix californiae and Neocallimastix lanati to Neocallimastix cameroonii and points towards the redesignation of Cyllamyces as a species of Caecomyces. All isolated strains including strain A252, which was described previously as Aestipascuomyces dubliciliberans, were further grown on different carbon sources and the produced metabolites were analyzed; hydrogen, acetate, formate, lactate, and succinate were the main products. Orpinomyces joyonii was lacking succinate production and Khoyollomyces ramosus was not able to produce lactate under the studied conditions. The results further suggested a sequential production of metabolites with a preference for hydrogen, acetate, and formate. By comparing fungal growth on monosaccharides or on the straw, a higher hydrogen production was noticed on the latter. Possible reactions to elevated sugar concentrations by anaerobic fungi are discussed.
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Affiliation(s)
- Marcus Stabel
- Process Engineering in Life Sciences 2: Technical Biology, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany; (T.S.); (K.H.); (P.G.); (H.A.); (K.O.)
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4
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Gyimesi G, Hediger MA. Sequence Features of Mitochondrial Transporter Protein Families. Biomolecules 2020; 10:E1611. [PMID: 33260588 PMCID: PMC7761412 DOI: 10.3390/biom10121611] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/20/2020] [Accepted: 11/22/2020] [Indexed: 02/08/2023] Open
Abstract
Mitochondrial carriers facilitate the transfer of small molecules across the inner mitochondrial membrane (IMM) to support mitochondrial function and core cellular processes. In addition to the classical SLC25 (solute carrier family 25) mitochondrial carriers, the past decade has led to the discovery of additional protein families with numerous members that exhibit IMM localization and transporter-like properties. These include mitochondrial pyruvate carriers, sideroflexins, and mitochondrial cation/H+ exchangers. These transport proteins were linked to vital physiological functions and disease. Their structures and transport mechanisms are, however, still largely unknown and understudied. Protein sequence analysis per se can often pinpoint hotspots that are of functional or structural importance. In this review, we summarize current knowledge about the sequence features of mitochondrial transporters with a special focus on the newly included SLC54, SLC55 and SLC56 families of the SLC solute carrier superfamily. Taking a step further, we combine sequence conservation analysis with transmembrane segment and secondary structure prediction methods to extract residue positions and sequence motifs that likely play a role in substrate binding, binding site gating or structural stability. We hope that our review will help guide future experimental efforts by the scientific community to unravel the transport mechanisms and structures of these novel mitochondrial carriers.
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Affiliation(s)
- Gergely Gyimesi
- Membrane Transport Discovery Lab, Department of Nephrology and Hypertension, and Department of Biomedical Research, Inselspital, University of Bern, Kinderklinik, Freiburgstrasse 15, CH-3010 Bern, Switzerland;
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5
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Zhang Y, Fernie AR. On the Detection and Functional Significance of the Protein-Protein Interactions of Mitochondrial Transport Proteins. Biomolecules 2020; 10:E1107. [PMID: 32722450 PMCID: PMC7464641 DOI: 10.3390/biom10081107] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/21/2020] [Accepted: 07/23/2020] [Indexed: 12/23/2022] Open
Abstract
Protein-protein assemblies are highly prevalent in all living cells. Considerable evidence has recently accumulated suggesting that particularly transient association/dissociation of proteins represent an important means of regulation of metabolism. This is true not only in the cytosol and organelle matrices, but also at membrane surfaces where, for example, receptor complexes, as well as those of key metabolic pathways, are common. Transporters also frequently come up in lists of interacting proteins, for example, binding proteins that catalyze the production of their substrates or that act as relays within signal transduction cascades. In this review, we provide an update of technologies that are used in the study of such interactions with mitochondrial transport proteins, highlighting the difficulties that arise in their use for membrane proteins and discussing our current understanding of the biological function of such interactions.
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Affiliation(s)
- Youjun Zhang
- Center of Plant Systems Biology and Biotechnology, 4000 Plovdiv, Bulgaria
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany
| | - Alisdair R. Fernie
- Center of Plant Systems Biology and Biotechnology, 4000 Plovdiv, Bulgaria
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany
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6
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Seppälä S, Yoo JI, Yur D, O'Malley MA. Heterologous transporters from anaerobic fungi bolster fluoride tolerance in Saccharomyces cerevisiae. Metab Eng Commun 2019; 9:e00091. [PMID: 31016136 PMCID: PMC6475669 DOI: 10.1016/j.mec.2019.e00091] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 03/22/2019] [Accepted: 04/09/2019] [Indexed: 12/21/2022] Open
Abstract
Membrane-embedded transporters are crucial for the stability and performance of microbial production strains. Apart from engineering known transporters derived from model systems, it is equally important to identify transporters from nonconventional organisms that confer advantageous traits for biotechnological applications. Here, we transferred genes encoding fluoride exporter (FEX) proteins from three strains of early-branching anaerobic fungi (Neocallimastigomycota) to Saccharomyces cerevisiae. The heterologous transporters are localized to the plasma membrane and complement a fluoride-sensitive yeast strain that is lacking endogenous fluoride transporters up to 10.24 mM fluoride. Furthermore, we show that fusing an amino-terminal leader sequence to FEX proteins in yeast elevates protein yields, yet inadvertently causes a loss of transporter function. Adaptive laboratory evolution of FEX proteins restores fluoride tolerance of these strains, in one case exceeding the solute tolerance observed in wild type S. cerevisiae; however, the underlying molecular mechanisms and cause for the increased tolerance in the evolved strains remain elusive. Our results suggest that microbial cultures can achieve solvent tolerance through different adaptive trajectories, and the study is a promising step towards the identification, production, and biotechnological application of membrane proteins from nonconventional fungi. First report describing the heterologous production of functional ion transport proteins sourced from anaerobic gut fungi. Codon-optimization enables production of functional, gut fungal membrane proteins in S. cerevisiae but not in E. coli. Addition of an N-terminal leader peptide elevates membrane protein yields yet diminishes cellular activity. Adaptive laboratory evolution restores cellular fluoride export activity in yeast to levels exceeding native tolerance.
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Affiliation(s)
- Susanna Seppälä
- Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA
| | - Justin I. Yoo
- Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA
| | - Daniel Yur
- Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA
| | - Michelle A. O'Malley
- Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA
- Corresponding author.
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7
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James TY, Letcher PM, Longcore JE, Mozley-Standridge SE, Porter D, Powell MJ, Griffith GW, Vilgalys R. A molecular phylogeny of the flagellated fungi (Chytridiomycota) and description of a new phylum (Blastocladiomycota). Mycologia 2017. [DOI: 10.1080/15572536.2006.11832616] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Timothy Y. James
- Department of Biology, Duke University, Durham, North Carolina 27708
| | - Peter M. Letcher
- Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama 35487
| | - Joyce E. Longcore
- Department of Biological Sciences, University of Maine, Orono, Maine 04469
| | | | - David Porter
- Department of Plant Biology, University of Georgia, Athens, Georgia 30605
| | - Martha J. Powell
- Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama 35487
| | - Gareth W. Griffith
- Institute of Biological Sciences, University of Wales, Aberystwyth, Ceredigion, Wales SY23 3DA, UK
| | - Rytas Vilgalys
- Department of Biology, Duke University, Durham, North Carolina 27708
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8
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Seppälä S, Solomon KV, Gilmore SP, Henske JK, O'Malley MA. Mapping the membrane proteome of anaerobic gut fungi identifies a wealth of carbohydrate binding proteins and transporters. Microb Cell Fact 2016; 15:212. [PMID: 27998268 PMCID: PMC5168858 DOI: 10.1186/s12934-016-0611-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 12/02/2016] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Engineered cell factories that convert biomass into value-added compounds are emerging as a timely alternative to petroleum-based industries. Although often overlooked, integral membrane proteins such as solute transporters are pivotal for engineering efficient microbial chassis. Anaerobic gut fungi, adapted to degrade raw plant biomass in the intestines of herbivores, are a potential source of valuable transporters for biotechnology, yet very little is known about the membrane constituents of these non-conventional organisms. Here, we mined the transcriptome of three recently isolated strains of anaerobic fungi to identify membrane proteins responsible for sensing and transporting biomass hydrolysates within a competitive and rather extreme environment. RESULTS Using sequence analyses and homology, we identified membrane protein-coding sequences from assembled transcriptomes from three strains of anaerobic gut fungi: Neocallimastix californiae, Anaeromyces robustus, and Piromyces finnis. We identified nearly 2000 transporter components: about half of these are involved in the general secretory pathway and intracellular sorting of proteins; the rest are predicted to be small-solute transporters. Unexpectedly, we found a number of putative sugar binding proteins that are associated with prokaryotic uptake systems; and approximately 100 class C G-protein coupled receptors (GPCRs) with non-canonical putative sugar binding domains. CONCLUSIONS We report the first comprehensive characterization of the membrane protein machinery of biotechnologically relevant anaerobic gut fungi. Apart from identifying conserved machinery for protein sorting and secretion, we identify a large number of putative solute transporters that are of interest for biotechnological applications. Notably, our data suggests that the fungi display a plethora of carbohydrate binding domains at their surface, perhaps as a means to sense and sequester some of the sugars that their biomass degrading, extracellular enzymes produce.
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Affiliation(s)
- Susanna Seppälä
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet Bygning 220, 2800, Kgs. Lyngby, Denmark.,Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA
| | - Kevin V Solomon
- Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA.,Agricultural and Biological Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Sean P Gilmore
- Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA
| | - John K Henske
- Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA
| | - Michelle A O'Malley
- Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA.
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9
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Garg S, Stölting J, Zimorski V, Rada P, Tachezy J, Martin WF, Gould SB. Conservation of Transit Peptide-Independent Protein Import into the Mitochondrial and Hydrogenosomal Matrix. Genome Biol Evol 2015; 7:2716-26. [PMID: 26338186 PMCID: PMC4607531 DOI: 10.1093/gbe/evv175] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The origin of protein import was a key step in the endosymbiotic acquisition of mitochondria. Though the main translocon of the mitochondrial outer membrane, TOM40, is ubiquitous among organelles of mitochondrial ancestry, the transit peptides, or N-terminal targeting sequences (NTSs), recognised by the TOM complex, are not. To better understand the nature of evolutionary conservation in mitochondrial protein import, we investigated the targeting behavior of Trichomonas vaginalis hydrogenosomal proteins in Saccharomyces cerevisiae and vice versa. Hydrogenosomes import yeast mitochondrial proteins even in the absence of their native NTSs, but do not import yeast cytosolic proteins. Conversely, yeast mitochondria import hydrogenosomal proteins with and without their short NTSs. Conservation of an NTS-independent mitochondrial import route from excavates to opisthokonts indicates its presence in the eukaryote common ancestor. Mitochondrial protein import is known to entail electrophoresis of positively charged NTSs across the electrochemical gradient of the inner mitochondrial membrane. Our present findings indicate that mitochondrial transit peptides, which readily arise from random sequences, were initially selected as a signal for charge-dependent protein targeting specifically to the mitochondrial matrix. Evolutionary loss of the electron transport chain in hydrogenosomes and mitosomes lifted the selective constraints that maintain positive charge in NTSs, allowing first the NTS charge, and subsequently the NTS itself, to be lost. This resulted in NTS-independent matrix targeting, which is conserved across the evolutionary divide separating trichomonads and yeast, and which we propose is the ancestral state of mitochondrial protein import.
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Affiliation(s)
- Sriram Garg
- Institute for Molecular Evolution, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Jan Stölting
- Institute for Molecular Evolution, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Verena Zimorski
- Institute for Molecular Evolution, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Petr Rada
- Department of Parasitology, Charles University in Prague, Faculty of Science, Czech Republic
| | - Jan Tachezy
- Department of Parasitology, Charles University in Prague, Faculty of Science, Czech Republic
| | - William F Martin
- Institute for Molecular Evolution, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Sven B Gould
- Institute for Molecular Evolution, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
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Dean P, Major P, Nakjang S, Hirt RP, Embley TM. Transport proteins of parasitic protists and their role in nutrient salvage. FRONTIERS IN PLANT SCIENCE 2014; 5:153. [PMID: 24808897 PMCID: PMC4010794 DOI: 10.3389/fpls.2014.00153] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Accepted: 04/01/2014] [Indexed: 05/02/2023]
Abstract
The loss of key biosynthetic pathways is a common feature of important parasitic protists, making them heavily dependent on scavenging nutrients from their hosts. This is often mediated by specialized transporter proteins that ensure the nutritional requirements of the parasite are met. Over the past decade, the completion of several parasite genome projects has facilitated the identification of parasite transporter proteins. This has been complemented by functional characterization of individual transporters along with investigations into their importance for parasite survival. In this review, we summarize the current knowledge on transporters from parasitic protists and highlight commonalities and differences in the transporter repertoires of different parasitic species, with particular focus on characterized transporters that act at the host-pathogen interface.
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Affiliation(s)
- Paul Dean
- *Correspondence: Paul Dean and T. Martin Embley, The Medical School, Institute for Cell and Molecular Biosciences, Newcastle University, Catherine Cookson Building, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK e-mail: ;
| | | | | | | | - T. Martin Embley
- *Correspondence: Paul Dean and T. Martin Embley, The Medical School, Institute for Cell and Molecular Biosciences, Newcastle University, Catherine Cookson Building, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK e-mail: ;
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Brás XP, Zimorski V, Bolte K, Maier UG, Martin WF, Gould SB. Knockout of the abundant Trichomonas vaginalis
hydrogenosomal membrane protein Tv
HMP23 increases hydrogenosome size but induces no compensatory up-regulation of paralogous copies. FEBS Lett 2013; 587:1333-9. [DOI: 10.1016/j.febslet.2013.03.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 02/28/2013] [Accepted: 03/01/2013] [Indexed: 11/25/2022]
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Müller M, Mentel M, van Hellemond JJ, Henze K, Woehle C, Gould SB, Yu RY, van der Giezen M, Tielens AGM, Martin WF. Biochemistry and evolution of anaerobic energy metabolism in eukaryotes. Microbiol Mol Biol Rev 2012; 76:444-95. [PMID: 22688819 PMCID: PMC3372258 DOI: 10.1128/mmbr.05024-11] [Citation(s) in RCA: 505] [Impact Index Per Article: 42.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Major insights into the phylogenetic distribution, biochemistry, and evolutionary significance of organelles involved in ATP synthesis (energy metabolism) in eukaryotes that thrive in anaerobic environments for all or part of their life cycles have accrued in recent years. All known eukaryotic groups possess an organelle of mitochondrial origin, mapping the origin of mitochondria to the eukaryotic common ancestor, and genome sequence data are rapidly accumulating for eukaryotes that possess anaerobic mitochondria, hydrogenosomes, or mitosomes. Here we review the available biochemical data on the enzymes and pathways that eukaryotes use in anaerobic energy metabolism and summarize the metabolic end products that they generate in their anaerobic habitats, focusing on the biochemical roles that their mitochondria play in anaerobic ATP synthesis. We present metabolic maps of compartmentalized energy metabolism for 16 well-studied species. There are currently no enzymes of core anaerobic energy metabolism that are specific to any of the six eukaryotic supergroup lineages; genes present in one supergroup are also found in at least one other supergroup. The gene distribution across lineages thus reflects the presence of anaerobic energy metabolism in the eukaryote common ancestor and differential loss during the specialization of some lineages to oxic niches, just as oxphos capabilities have been differentially lost in specialization to anoxic niches and the parasitic life-style. Some facultative anaerobes have retained both aerobic and anaerobic pathways. Diversified eukaryotic lineages have retained the same enzymes of anaerobic ATP synthesis, in line with geochemical data indicating low environmental oxygen levels while eukaryotes arose and diversified.
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Affiliation(s)
| | - Marek Mentel
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia
| | - Jaap J. van Hellemond
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Katrin Henze
- Institute of Molecular Evolution, University of Düsseldorf, Düsseldorf, Germany
| | - Christian Woehle
- Institute of Molecular Evolution, University of Düsseldorf, Düsseldorf, Germany
| | - Sven B. Gould
- Institute of Molecular Evolution, University of Düsseldorf, Düsseldorf, Germany
| | - Re-Young Yu
- Institute of Molecular Evolution, University of Düsseldorf, Düsseldorf, Germany
| | - Mark van der Giezen
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - Aloysius G. M. Tielens
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, Netherlands
| | - William F. Martin
- Institute of Molecular Evolution, University of Düsseldorf, Düsseldorf, Germany
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13
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Haferkamp I, Schmitz-Esser S. The plant mitochondrial carrier family: functional and evolutionary aspects. FRONTIERS IN PLANT SCIENCE 2012; 3:2. [PMID: 22639632 PMCID: PMC3355725 DOI: 10.3389/fpls.2012.00002] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Accepted: 01/03/2012] [Indexed: 05/19/2023]
Abstract
Mitochondria play a key role in respiration and energy production and are involved in multiple eukaryotic but also in several plant specific metabolic pathways. Solute carriers in the inner mitochondrial membrane connect the internal metabolism with that of the surrounding cell. Because of their common basic structure, these transport proteins affiliate to the mitochondrial carrier family (MCF). Generally, MCF proteins consist of six membrane spanning helices, exhibit typical conserved domains and appear as homodimers in the native membrane. Although structurally related, MCF proteins catalyze the specific transport of various substrates, such as nucleotides, amino acids, dicarboxylates, cofactors, phosphate or H(+). Recent investigations identified MCF proteins also in several other cellular compartments and therefore their localization and physiological function is not only restricted to mitochondria. MCF proteins are a characteristic feature of eukaryotes and bacterial genomes lack corresponding sequences. Therefore, the evolutionary origin of MCF proteins is most likely associated with the establishment of mitochondria. It is not clear whether the host cell, the symbiont, or the chimerical organism invented the ancient MCF sequence. Here, we try to explain the establishment of different MCF proteins and focus on the characteristics of members from plants, in particular from Arabidopsis thaliana.
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Affiliation(s)
- Ilka Haferkamp
- Zelluläre Physiologie/Membrantransport, Technische Universität KaiserslauternKaiserslautern, Germany
- *Correspondence: Ilka Haferkamp, Biologie, Zelluläre Physiologie/Membrantransport, Technische Universität Kaiserslautern, Erwin-Schrödinger-Str. 22, 67653 Kaiserslautern, Germany. e-mail:
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14
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Tsaousis AD, Leger MM, Stairs CAW, Roger AJ. The Biochemical Adaptations of Mitochondrion-Related Organelles of Parasitic and Free-Living Microbial Eukaryotes to Low Oxygen Environments. CELLULAR ORIGIN, LIFE IN EXTREME HABITATS AND ASTROBIOLOGY 2012. [DOI: 10.1007/978-94-007-1896-8_4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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15
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Saccà A. The Role of Eukaryotes in the Anaerobic Food Web of Stratified Lakes. CELLULAR ORIGIN, LIFE IN EXTREME HABITATS AND ASTROBIOLOGY 2012. [DOI: 10.1007/978-94-007-1896-8_21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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16
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Hydrogenosomes and Mitosomes: Mitochondrial Adaptations to Life in Anaerobic Environments. CELLULAR ORIGIN, LIFE IN EXTREME HABITATS AND ASTROBIOLOGY 2012. [DOI: 10.1007/978-94-007-1896-8_5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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17
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Rada P, Doležal P, Jedelský PL, Bursac D, Perry AJ, Šedinová M, Smíšková K, Novotný M, Beltrán NC, Hrdý I, Lithgow T, Tachezy J. The core components of organelle biogenesis and membrane transport in the hydrogenosomes of Trichomonas vaginalis. PLoS One 2011; 6:e24428. [PMID: 21935410 PMCID: PMC3174187 DOI: 10.1371/journal.pone.0024428] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Accepted: 08/09/2011] [Indexed: 12/02/2022] Open
Abstract
Trichomonas vaginalis is a parasitic protist of the Excavata group. It contains an anaerobic form of mitochondria called hydrogenosomes, which produce hydrogen and ATP; the majority of mitochondrial pathways and the organellar genome were lost during the mitochondrion-to-hydrogenosome transition. Consequently, all hydrogenosomal proteins are encoded in the nucleus and imported into the organelles. However, little is known about the membrane machineries required for biogenesis of the organelle and metabolite exchange. Using a combination of mass spectrometry, immunofluorescence microscopy, in vitro import assays and reverse genetics, we characterized the membrane proteins of the hydrogenosome. We identified components of the outer membrane (TOM) and inner membrane (TIM) protein translocases include multiple paralogs of the core Tom40-type porins and Tim17/22/23 channel proteins, respectively, and uniquely modified small Tim chaperones. The inner membrane proteins TvTim17/22/23-1 and Pam18 were shown to possess conserved information for targeting to mitochondrial inner membranes, but too divergent in sequence to support the growth of yeast strains lacking Tim17, Tim22, Tim23 or Pam18. Full complementation was seen only when the J-domain of hydrogenosomal Pam18 was fused with N-terminal region and transmembrane segment of the yeast homolog. Candidates for metabolite exchange across the outer membrane were identified including multiple isoforms of the β-barrel proteins, Hmp35 and Hmp36; inner membrane MCF-type metabolite carriers were limited to five homologs of the ATP/ADP carrier, Hmp31. Lastly, hydrogenosomes possess a pathway for the assembly of C-tail-anchored proteins into their outer membrane with several new tail-anchored proteins being identified. These results show that hydrogenosomes and mitochondria share common core membrane components required for protein import and metabolite exchange; however, they also reveal remarkable differences that reflect the functional adaptation of hydrogenosomes to anaerobic conditions and the peculiar evolutionary history of the Excavata group.
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Affiliation(s)
- Petr Rada
- Department of Parasitology, Charles University in Prague, Faculty of Science, Prague, Czech Republic
| | - Pavel Doležal
- Department of Parasitology, Charles University in Prague, Faculty of Science, Prague, Czech Republic
| | - Petr L. Jedelský
- Department of Parasitology, Charles University in Prague, Faculty of Science, Prague, Czech Republic
- Laboratory of Mass Spectrometry, Charles University in Prague, Faculty of Science, Prague, Czech Republic
| | - Dejan Bursac
- Department of Biochemistry & Molecular Biology, Monash University, Melbourne, Australia
| | - Andrew J. Perry
- Department of Biochemistry & Molecular Biology, Monash University, Melbourne, Australia
| | - Miroslava Šedinová
- Department of Parasitology, Charles University in Prague, Faculty of Science, Prague, Czech Republic
| | - Kateřina Smíšková
- Department of Parasitology, Charles University in Prague, Faculty of Science, Prague, Czech Republic
| | - Marian Novotný
- Department of Parasitology, Charles University in Prague, Faculty of Science, Prague, Czech Republic
| | - Neritza Campo Beltrán
- Department of Parasitology, Charles University in Prague, Faculty of Science, Prague, Czech Republic
| | - Ivan Hrdý
- Department of Parasitology, Charles University in Prague, Faculty of Science, Prague, Czech Republic
| | - Trevor Lithgow
- Department of Biochemistry & Molecular Biology, Monash University, Melbourne, Australia
| | - Jan Tachezy
- Department of Parasitology, Charles University in Prague, Faculty of Science, Prague, Czech Republic
- * E-mail:
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18
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Traba J, Satrústegui J, del Arco A. Adenine nucleotide transporters in organelles: novel genes and functions. Cell Mol Life Sci 2011; 68:1183-206. [PMID: 21207102 PMCID: PMC11114886 DOI: 10.1007/s00018-010-0612-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 11/16/2010] [Accepted: 12/09/2010] [Indexed: 10/18/2022]
Abstract
In eukaryotes, cellular energy in the form of ATP is produced in the cytosol via glycolysis or in the mitochondria via oxidative phosphorylation and, in photosynthetic organisms, in the chloroplast via photophosphorylation. Transport of adenine nucleotides among cell compartments is essential and is performed mainly by members of the mitochondrial carrier family, among which the ADP/ATP carriers are the best known. This work reviews the carriers that transport adenine nucleotides into the organelles of eukaryotic cells together with their possible functions. We focus on novel mechanisms of adenine nucleotide transport, including mitochondrial carriers found in organelles such as peroxisomes, plastids, or endoplasmic reticulum and also mitochondrial carriers found in the mitochondrial remnants of many eukaryotic parasites of interest. The extensive repertoire of adenine nucleotide carriers highlights an amazing variety of new possible functions of adenine nucleotide transport across eukaryotic organelles.
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Affiliation(s)
- Javier Traba
- Departamento de Biología Molecular, Centro de Biología Molecular Severo Ochoa UAM-CSIC, CIBER de Enfermedades Raras, Universidad Autónoma de Madrid, Madrid, Spain.
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Abstract
The discovery of mitochondrion-type genes in organisms thought to lack mitochondria led to the demonstration that hydrogenosomes share a common ancestry with mitochondria, as well as the discovery of mitosomes in multiple eukaryotic lineages. No examples of examined eukaryotes lacking a mitochondrion-related organelle exist, implying that the endosymbiont that gave rise to the mitochondrion was present in the first eukaryote. These organelles, known as hydrogenosomes, mitosomes, or mitochondrion-like organelles, are typically reduced, both structurally and biochemically, relative to classical mitochondria. However, despite their diversification and adaptation to different niches, all appear to play a role in Fe-S cluster assembly, as observed for mitochondria. Although evidence supports the use of common protein targeting mechanisms in the biogenesis of these diverse organelles, divergent features are also apparent. This review examines the metabolism and biogenesis of these organelles in divergent unicellular microbes, with a focus on parasitic protists.
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Affiliation(s)
- April M Shiflett
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, California 90095-1489, USA
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20
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Allen JF. Why chloroplasts and mitochondria contain genomes. Comp Funct Genomics 2010; 4:31-6. [PMID: 18629105 PMCID: PMC2447392 DOI: 10.1002/cfg.245] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2002] [Accepted: 11/25/2002] [Indexed: 11/05/2022] Open
Abstract
Chloroplasts and mitochondria originated as bacterial symbionts. The larger, host
cells acquired genetic information from their prokaryotic guests by lateral gene
transfer. The prokaryotically-derived genes of the eukaryotic cell nucleus now
function to encode the great majority of chloroplast and mitochondrial proteins,
as well as many proteins of the nucleus and cytosol. Genes are copied and moved
between cellular compartments with relative ease, and there is no established obstacle
to successful import of any protein precursor from the cytosol. Yet chloroplasts and
mitochondria have not abdicated all genes and gene expression to the nucleus and
to cytosolic translation. What, then, do chloroplast- and mitochondrially-encoded
proteins have in common that confers a selective advantage on the cytoplasmic
location of their genes? The proposal advanced here is that co-location of chloroplast
and mitochondrial genes with their gene products is required for rapid and direct
regulatory coupling. Redox control of gene expression is suggested as the common
feature of those chloroplast and mitochondrial proteins that are encoded in situ.
Recent evidence is consistent with this hypothesis, and its underlying assumptions
and predictions are described.
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Affiliation(s)
- John F Allen
- Plant Biochemistry, Center for Chemistry and Chemical Engineering, Lund University, Lund SE-221 00, Sweden.
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Hjort K, Goldberg AV, Tsaousis AD, Hirt RP, Embley TM. Diversity and reductive evolution of mitochondria among microbial eukaryotes. Philos Trans R Soc Lond B Biol Sci 2010; 365:713-27. [PMID: 20124340 DOI: 10.1098/rstb.2009.0224] [Citation(s) in RCA: 137] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
All extant eukaryotes are now considered to possess mitochondria in one form or another. Many parasites or anaerobic protists have highly reduced versions of mitochondria, which have generally lost their genome and the capacity to generate ATP through oxidative phosphorylation. These organelles have been called hydrogenosomes, when they make hydrogen, or remnant mitochondria or mitosomes when their functions were cryptic. More recently, organelles with features blurring the distinction between mitochondria, hydrogenosomes and mitosomes have been identified. These organelles have retained a mitochondrial genome and include the mitochondrial-like organelle of Blastocystis and the hydrogenosome of the anaerobic ciliate Nyctotherus. Studying eukaryotic diversity from the perspective of their mitochondrial variants has yielded important insights into eukaryote molecular cell biology and evolution. These investigations are contributing to understanding the essential functions of mitochondria, defined in the broadest sense, and the limits to which reductive evolution can proceed while maintaining a viable organelle.
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Affiliation(s)
- Karin Hjort
- Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne NE2 4HH, UK
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VAN DER GIEZEN MARK. Hydrogenosomes and Mitosomes: Conservation and Evolution of Functions. J Eukaryot Microbiol 2009; 56:221-31. [DOI: 10.1111/j.1550-7408.2009.00407.x] [Citation(s) in RCA: 137] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Gaston D, Tsaousis AD, Roger AJ. Predicting proteomes of mitochondria and related organelles from genomic and expressed sequence tag data. Methods Enzymol 2009; 457:21-47. [PMID: 19426860 DOI: 10.1016/s0076-6879(09)05002-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In eukaryotes, determination of the subcellular location of a novel protein encoded in genomic or transcriptomic data provides useful clues as to its possible function. However, experimental localization studies are expensive and time-consuming. As a result, accurate in silico prediction of subcellular localization from sequence data alone is an extremely important field of study in bioinformatics. This is especially so as genomic studies expand beyond model system organisms to encompass the full diversity of eukaryotes. Here we review some of the more commonly used programs for prediction of proteins that function in mitochondria, or mitochondrion-related organelles in diverse eukaryotic lineages and provide recommendations on how to apply these methods. Furthermore, we compare the predictive performance of these programs on a mixed set of mitochondrial and non-mitochondrial proteins. Although N-terminal targeting peptide prediction programs tend to have the highest accuracy, they cannot be effectively used for partial coding sequences derived from high-throughput expressed sequence tag surveys where data for the N-terminus of the encoded protein is often missing. Therefore methods that do not rely on the presence of an N-terminal targeting sequence alone are extremely useful, especially for expressed sequence tag data. The best strategy for classification of unknown proteins is to use multiple programs, incorporating a variety of prediction strategies, and closely examine the predictions with an understanding of how each of those programs will likely handle the data.
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Affiliation(s)
- Daniel Gaston
- Centre for Comparative Genomics and Evolutionary Bioinformatics, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
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Protein import into hydrogenosomes of Trichomonas vaginalis involves both N-terminal and internal targeting signals: a case study of thioredoxin reductases. EUKARYOTIC CELL 2008; 7:1750-7. [PMID: 18676956 DOI: 10.1128/ec.00206-08] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The parabasalian flagellate Trichomonas vaginalis harbors mitochondrion-related and H(2)-producing organelles of anaerobic ATP synthesis, called hydrogenosomes, which harbor oxygen-sensitive enzymes essential to its pyruvate metabolism. In the human urogenital tract, however, T. vaginalis is regularly exposed to low oxygen concentrations and therefore must possess antioxidant systems protecting the organellar environment against the detrimental effects of molecular oxygen and reactive oxygen species. We have identified two closely related hydrogenosomal thioredoxin reductases (TrxRs), the hitherto-missing component of a thioredoxin-linked hydrogenosomal antioxidant system. One of the two hydrogenosomal TrxR isoforms, TrxRh1, carried an N-terminal extension resembling known hydrogenosomal targeting signals. Expression of hemagglutinin-tagged TrxRh1 in transfected T. vaginalis cells revealed that its N-terminal extension was necessary to import the protein into the organelles. The second hydrogenosomal TrxR isoform, TrxRh2, had no N-terminal targeting signal but was nonetheless efficiently targeted to hydrogenosomes. N-terminal presequences from hydrogenosomal proteins with known processing sites, i.e., the alpha subunit of succinyl coenzyme A synthetase (SCSalpha) and pyruvate:ferredoxin oxidoreductase A, were investigated for their ability to direct mature TrxRh1 to hydrogenosomes. Neither presequence directed TrxRh1 to hydrogenosomes, indicating that neither extension is, by itself, sufficient for hydrogenosomal targeting. Moreover, SCSalpha lacking its N-terminal extension was efficiently imported into hydrogenosomes, indicating that this extension is not required for import of this major hydrogenosomal protein. The finding that some hydrogenosomal enzymes require N-terminal signals for import but that in others the N-terminal extension is not necessary for targeting indicates the presence of additional targeting signals within the mature subunits of several hydrogenosome-localized proteins.
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Stechmann A, Hamblin K, Pérez-Brocal V, Gaston D, Richmond GS, van der Giezen M, Clark CG, Roger AJ. Organelles in Blastocystis that blur the distinction between mitochondria and hydrogenosomes. Curr Biol 2008; 18:580-5. [PMID: 18403202 PMCID: PMC2428068 DOI: 10.1016/j.cub.2008.03.037] [Citation(s) in RCA: 122] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2007] [Revised: 03/12/2008] [Accepted: 03/13/2008] [Indexed: 11/25/2022]
Abstract
Blastocystis is a unicellular stramenopile of controversial pathogenicity in humans. Although it is a strict anaerobe, Blastocystis has mitochondrion-like organelles with cristae, a transmembrane potential and DNA. An apparent lack of several typical mitochondrial pathways has led some to suggest that these organelles might be hydrogenosomes, anaerobic organelles related to mitochondria. We generated 12,767 expressed sequence tags (ESTs) from Blastocystis and identified 115 clusters that encode putative mitochondrial and hydrogenosomal proteins. Among these is the canonical hydrogenosomal protein iron-only [FeFe] hydrogenase that we show localizes to the organelles. The organelles also have mitochondrial characteristics, including pathways for amino acid metabolism, iron-sulfur cluster biogenesis, and an incomplete tricarboxylic acid cycle as well as a mitochondrial genome. Although complexes I and II of the electron transport chain (ETC) are present, we found no evidence for complexes III and IV or F1Fo ATPases. The Blastocystis organelles have metabolic properties of aerobic and anaerobic mitochondria and of hydrogenosomes. They are convergently similar to organelles recently described in the unrelated ciliate Nyctotherus ovalis. These findings blur the boundaries between mitochondria, hydrogenosomes, and mitosomes, as currently defined, underscoring the disparate selective forces that shape these organelles in eukaryotes.
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Affiliation(s)
- Alexandra Stechmann
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, B3H 1X5, Canada.
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27
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Allen JWA, Jackson AP, Rigden DJ, Willis AC, Ferguson SJ, Ginger ML. Order within a mosaic distribution of mitochondrial c-type cytochrome biogenesis systems? FEBS J 2008; 275:2385-402. [PMID: 18393999 DOI: 10.1111/j.1742-4658.2008.06380.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Mitochondrial cytochromes c and c(1) are present in all eukaryotes that use oxygen as the terminal electron acceptor in the respiratory chain. Maturation of c-type cytochromes requires covalent attachment of the heme cofactor to the protein, and there are at least five distinct biogenesis systems that catalyze this post-translational modification in different organisms and organelles. In this study, we use biochemical data, comparative genomic and structural bioinformatics investigations to provide a holistic view of mitochondrial c-type cytochrome biogenesis and its evolution. There are three pathways for mitochondrial c-type cytochrome maturation, only one of which is present in prokaryotes. We analyze the evolutionary distribution of these biogenesis systems, which include the Ccm system (System I) and the enzyme heme lyase (System III). We conclude that heme lyase evolved once and, in many lineages, replaced the multicomponent Ccm system (present in the proto-mitochondrial endosymbiont), probably as a consequence of lateral gene transfer. We find no evidence of a System III precursor in prokaryotes, and argue that System III is incompatible with multi-heme cytochromes common to bacteria, but absent from eukaryotes. The evolution of the eukaryotic-specific protein heme lyase is strikingly unusual, given that this protein provides a function (thioether bond formation) that is also ubiquitous in prokaryotes. The absence of any known c-type cytochrome biogenesis system from the sequenced genomes of various trypanosome species indicates the presence of a third distinct mitochondrial pathway. Interestingly, this system attaches heme to mitochondrial cytochromes c that contain only one cysteine residue, rather than the usual two, within the heme-binding motif. The isolation of single-cysteine-containing mitochondrial cytochromes c from free-living kinetoplastids, Euglena and the marine flagellate Diplonema papillatum suggests that this unique form of heme attachment is restricted to, but conserved throughout, the protist phylum Euglenozoa.
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28
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Williams BA, Haferkamp I, Keeling PJ. An ADP/ATP-Specific Mitochondrial Carrier Protein in the Microsporidian Antonospora locustae. J Mol Biol 2008; 375:1249-57. [DOI: 10.1016/j.jmb.2007.11.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Revised: 11/01/2007] [Accepted: 11/05/2007] [Indexed: 11/27/2022]
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29
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Hampl V, Silberman JD, Stechmann A, Diaz-Triviño S, Johnson PJ, Roger AJ. Genetic evidence for a mitochondriate ancestry in the 'amitochondriate' flagellate Trimastix pyriformis. PLoS One 2008; 3:e1383. [PMID: 18167542 PMCID: PMC2148110 DOI: 10.1371/journal.pone.0001383] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2007] [Accepted: 12/07/2007] [Indexed: 11/24/2022] Open
Abstract
Most modern eukaryotes diverged from a common ancestor that contained the α-proteobacterial endosymbiont that gave rise to mitochondria. The ‘amitochondriate’ anaerobic protist parasites that have been studied to date, such as Giardia and Trichomonas harbor mitochondrion-related organelles, such as mitosomes or hydrogenosomes. Yet there is one remaining group of mitochondrion-lacking flagellates known as the Preaxostyla that could represent a primitive ‘pre-mitochondrial’ lineage of eukaryotes. To test this hypothesis, we conducted an expressed sequence tag (EST) survey on the preaxostylid flagellate Trimastix pyriformis, a poorly-studied free-living anaerobe. Among the ESTs we detected 19 proteins that, in other eukaryotes, typically function in mitochondria, hydrogenosomes or mitosomes, 12 of which are found exclusively within these organelles. Interestingly, one of the proteins, aconitase, functions in the tricarboxylic acid cycle typical of aerobic mitochondria, whereas others, such as pyruvate:ferredoxin oxidoreductase and [FeFe] hydrogenase, are characteristic of anaerobic hydrogenosomes. Since Trimastix retains genetic evidence of a mitochondriate ancestry, we can now say definitively that all known living eukaryote lineages descend from a common ancestor that had mitochondria.
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Affiliation(s)
- Vladimir Hampl
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jeffrey D. Silberman
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Biological Sciences, University of Arkansas, Fayetteville, Arkansas, United States of America
| | - Alexandra Stechmann
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Sara Diaz-Triviño
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Patricia J. Johnson
- Department of Microbiology, Immunology, and Molecular Genetics, University of California at Los Angeles, Los Angeles, California, United States of America
| | - Andrew J. Roger
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
- * To whom correspondence should be addressed. E-mail:
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30
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van Grinsven KWA, Rosnowsky S, van Weelden SWH, Pütz S, van der Giezen M, Martin W, van Hellemond JJ, Tielens AGM, Henze K. Acetate:succinate CoA-transferase in the hydrogenosomes of Trichomonas vaginalis: identification and characterization. J Biol Chem 2007; 283:1411-1418. [PMID: 18024431 DOI: 10.1074/jbc.m702528200] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Acetate:succinate CoA-transferases (ASCT) are acetate-producing enzymes in hydrogenosomes, anaerobically functioning mitochondria and in the aerobically functioning mitochondria of trypanosomatids. Although acetate is produced in the hydrogenosomes of a number of anaerobic microbial eukaryotes such as Trichomonas vaginalis, no acetate producing enzyme has ever been identified in these organelles. Acetate production is the last unidentified enzymatic reaction of hydrogenosomal carbohydrate metabolism. We identified a gene encoding an enzyme for acetate production in the genome of the hydrogenosome-containing protozoan parasite T. vaginalis. This gene shows high similarity to Saccharomyces cerevisiae acetyl-CoA hydrolase and Clostridium kluyveri succinyl-CoA:CoA-transferase. Here we demonstrate that this protein is expressed and is present in the hydrogenosomes where it functions as the T. vaginalis acetate:succinate CoA-transferase (TvASCT). Heterologous expression of TvASCT in CHO cells resulted in the expression of an active ASCT. Furthermore, homologous overexpression of the TvASCT gene in T. vaginalis resulted in an equivalent increase in ASCT activity. It was shown that the CoA transferase activity is succinate-dependent. These results demonstrate that this acetyl-CoA hydrolase/transferase homolog functions as the hydrogenosomal ASCT of T. vaginalis. This is the first hydrogenosomal acetate-producing enzyme to be identified. Interestingly, TvASCT does not share any similarity with the mitochondrial ASCT from Trypanosoma brucei, the only other eukaryotic succinate-dependent acetyl-CoA-transferase identified so far. The trichomonad enzyme clearly belongs to a distinct class of acetate:succinate CoA-transferases. Apparently, two completely different enzymes for succinate-dependent acetate production have evolved independently in ATP-generating organelles.
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Affiliation(s)
- Koen W A van Grinsven
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 2, 3584 CM Utrecht, The Netherlands
| | - Silke Rosnowsky
- Institute of Botany III, Heinrich Heine University, Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Susanne W H van Weelden
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 2, 3584 CM Utrecht, The Netherlands
| | - Simone Pütz
- Institute of Botany III, Heinrich Heine University, Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Mark van der Giezen
- Centre for Eukaryotic Evolutionary Microbiology, School of Biosciences, University of Exeter, Stocker Road, Exeter EX4 4QD, United Kingdom
| | - William Martin
- Institute of Botany III, Heinrich Heine University, Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Jaap J van Hellemond
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 2, 3584 CM Utrecht, The Netherlands; Department of Medical Microbiology & Infectious Diseases, ErasmusMC University Medical Center, Dr. Molewaterplein 40, 3015 GD Rotterdam, The Netherlands
| | - Aloysius G M Tielens
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 2, 3584 CM Utrecht, The Netherlands; Department of Medical Microbiology & Infectious Diseases, ErasmusMC University Medical Center, Dr. Molewaterplein 40, 3015 GD Rotterdam, The Netherlands
| | - Katrin Henze
- Institute of Botany III, Heinrich Heine University, Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany.
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Vignais PM, Billoud B. Occurrence, Classification, and Biological Function of Hydrogenases: An Overview. Chem Rev 2007; 107:4206-72. [PMID: 17927159 DOI: 10.1021/cr050196r] [Citation(s) in RCA: 1034] [Impact Index Per Article: 60.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Paulette M. Vignais
- CEA Grenoble, Laboratoire de Biochimie et Biophysique des Systèmes Intégrés, UMR CEA/CNRS/UJF 5092, Institut de Recherches en Technologies et Sciences pour le Vivant (iRTSV), 17 rue des Martyrs, 38054 Grenoble cedex 9, France, and Atelier de BioInformatique Université Pierre et Marie Curie (Paris 6), 12 rue Cuvier, 75005 Paris, France
| | - Bernard Billoud
- CEA Grenoble, Laboratoire de Biochimie et Biophysique des Systèmes Intégrés, UMR CEA/CNRS/UJF 5092, Institut de Recherches en Technologies et Sciences pour le Vivant (iRTSV), 17 rue des Martyrs, 38054 Grenoble cedex 9, France, and Atelier de BioInformatique Université Pierre et Marie Curie (Paris 6), 12 rue Cuvier, 75005 Paris, France
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Bamber L, Harding M, Monné M, Slotboom DJ, Kunji ERS. The yeast mitochondrial ADP/ATP carrier functions as a monomer in mitochondrial membranes. Proc Natl Acad Sci U S A 2007; 104:10830-4. [PMID: 17566106 PMCID: PMC1891095 DOI: 10.1073/pnas.0703969104] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2007] [Indexed: 11/18/2022] Open
Abstract
Mitochondrial carriers are believed widely to be dimers both in structure and function. However, the structural fold is a barrel of six transmembrane alpha-helices without an obvious dimerisation interface. Here, we show by negative dominance studies that the yeast mitochondrial ADP/ATP carrier 2 from Saccharomyces cerevisiae (AAC2) is functional as a monomer in the mitochondrial membrane. Adenine nucleotide transport by wild-type AAC2 is inhibited by the sulfhydryl reagent 2-sulfonatoethyl-methanethiosulfonate (MTSES), whereas the activity of a mutant AAC2, devoid of cysteines, is unaffected. Wild-type and cysteine-less AAC2 were coexpressed in different molar ratios in yeast mitochondrial membranes. After addition of MTSES the residual transport activity correlated linearly with the fraction of cysteine-less carrier present in the membranes, and so the two versions functioned independently of each other. Also, the cysteine-less and wild-type carriers were purified separately, mixed in defined ratios and reconstituted into liposomes. Again, the residual transport activity in the presence of MTSES depended linearly on the amount of cysteine-less carrier. Thus, the entire transport cycle for ADP/ATP exchange is carried out by the monomer.
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Affiliation(s)
- Lisa Bamber
- Medical Research Council, Dunn Human Nutrition Unit, Hills Road, Cambridge CB2 2XY, United Kingdom
| | - Marilyn Harding
- Medical Research Council, Dunn Human Nutrition Unit, Hills Road, Cambridge CB2 2XY, United Kingdom
| | - Magnus Monné
- Medical Research Council, Dunn Human Nutrition Unit, Hills Road, Cambridge CB2 2XY, United Kingdom
| | - Dirk-Jan Slotboom
- Medical Research Council, Dunn Human Nutrition Unit, Hills Road, Cambridge CB2 2XY, United Kingdom
| | - Edmund R. S. Kunji
- Medical Research Council, Dunn Human Nutrition Unit, Hills Road, Cambridge CB2 2XY, United Kingdom
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33
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Bamber L, Slotboom DJ, Kunji ERS. Yeast mitochondrial ADP/ATP carriers are monomeric in detergents as demonstrated by differential affinity purification. J Mol Biol 2007; 371:388-95. [PMID: 17572439 DOI: 10.1016/j.jmb.2007.05.072] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2007] [Revised: 05/23/2007] [Accepted: 05/24/2007] [Indexed: 10/23/2022]
Abstract
Most mitochondrial carriers carry out equimolar exchange of substrates and they are believed widely to exist as homo-dimers. Here we show by differential tagging that the yeast mitochondrial ADP/ATP carrier AAC2 is a monomer in mild detergents. Carriers with and without six-histidine or hemagglutinin tags were co-expressed in defined molar ratios in yeast mitochondrial membranes. Their specific transport activity was unaffected by tagging or by co-expression. The co-expressed carriers were extracted from the membranes with mild detergents and purified rapidly by affinity chromatography. All of the untagged carriers were in the flow-through of the affinity column, whereas all of the tagged carriers bound to the column and were eluted subsequently, showing that stable dimers, consisting of associated tagged and untagged carriers, were not present. The specific inhibitors carboxyatractyloside and bongkrekic acid and the substrates ADP, ATP and ADP plus ATP were added during the experiments to determine whether lack of association might have been caused by carriers being prevented from cycling through the various states in the transport cycle where dimers might form. All of the protein was accounted for, but stable dimers were not detected in any of these conditions, showing that yeast ADP/ATP carriers are monomeric in detergents in agreement with their hydrodynamic properties and with their structure. Since strong interactions between monomers were not observed in any part of the transport cycle, it is highly unlikely that the carriers function cooperatively. Therefore, transport mechanisms need to be considered in which the carrier is operational as a monomer.
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Affiliation(s)
- Lisa Bamber
- The Medical Research Council, Dunn Human Nutrition Unit, Hills Road, CB2 2XY, Cambridge, UK
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Mukherjee M, Brown MT, McArthur AG, Johnson PJ. Proteins of the glycine decarboxylase complex in the hydrogenosome of Trichomonas vaginalis. EUKARYOTIC CELL 2007; 5:2062-71. [PMID: 17158739 PMCID: PMC1694811 DOI: 10.1128/ec.00205-06] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Trichomonas vaginalis is a unicellular eukaryote that lacks mitochondria and contains a specialized organelle, the hydrogenosome, involved in carbohydrate metabolism and iron-sulfur cluster assembly. We report the identification of two glycine cleavage H proteins and a dihydrolipoamide dehydrogenase (L protein) of the glycine decarboxylase complex in T. vaginalis with predicted N-terminal hydrogenosomal presequences. Immunofluorescence analyses reveal that both H and L proteins are localized in hydrogenosomes, providing the first evidence for amino acid metabolism in this organelle. All three proteins were expressed in Escherichia coli and purified to homogeneity. The experimental Km of L protein for the two H proteins were 2.6 microM and 3.7 microM, consistent with both H proteins serving as substrates of L protein. Analyses using purified hydrogenosomes showed that endogenous H proteins exist as monomers and endogenous L protein as a homodimer in their native states. Phylogenetic analyses of L proteins revealed that the T. vaginalis homologue shares a common ancestry with dihydrolipoamide dehydrogenases from the firmicute bacteria, indicating its acquisition via a horizontal gene transfer event independent of the origins of mitochondria and hydrogenosomes.
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Affiliation(s)
- Mandira Mukherjee
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, 609 Charles E. Young Drive East, Los Angeles, CA 90095-1489, USA
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Satrústegui J, Pardo B, Del Arco A. Mitochondrial Transporters as Novel Targets for Intracellular Calcium Signaling. Physiol Rev 2007; 87:29-67. [PMID: 17237342 DOI: 10.1152/physrev.00005.2006] [Citation(s) in RCA: 203] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ca2+signaling in mitochondria is important to tune mitochondrial function to a variety of extracellular stimuli. The main mechanism is Ca2+entry in mitochondria via the Ca2+uniporter followed by Ca2+activation of three dehydrogenases in the mitochondrial matrix. This results in increases in mitochondrial NADH/NAD ratios and ATP levels and increased substrate uptake by mitochondria. We review evidence gathered more than 20 years ago and recent work indicating that substrate uptake, mitochondrial NADH/NAD ratios, and ATP levels may be also activated in response to cytosolic Ca2+signals via a mechanism that does not require the entry of Ca2+in mitochondria, a mechanism depending on the activity of Ca2+-dependent mitochondrial carriers (CaMC). CaMCs fall into two groups, the aspartate-glutamate carriers (AGC) and the ATP-Mg/Picarriers, also named SCaMC (for short CaMC). The two mammalian AGCs, aralar and citrin, are members of the malate-aspartate NADH shuttle, and citrin, the liver AGC, is also a member of the urea cycle. Both types of CaMCs are activated by Ca2+in the intermembrane space and function together with the Ca2+uniporter in decoding the Ca2+signal into a mitochondrial response.
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Affiliation(s)
- Jorgina Satrústegui
- Departamento de Biología Molecular Centro de Biología Molecular "Severo Ochoa" UAM-CSIC, Facultad de Ciencias, Universidad Autónoma, Madrid, Spain.
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Burri L, Keeling PJ. Protein targeting in parasites with cryptic mitochondria. Int J Parasitol 2006; 37:265-72. [PMID: 17250838 DOI: 10.1016/j.ijpara.2006.12.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2006] [Revised: 12/05/2006] [Accepted: 12/11/2006] [Indexed: 11/22/2022]
Abstract
Many highly specialised parasites have adapted to their environments by simplifying different aspects of their morphology or biochemistry. One interesting case is the mitochondrion, which has been subject to strong reductive evolution in parallel in several different parasitic groups. In extreme cases, mitochondria have degenerated so much in physical size and functional complexity that they were not immediately recognised as mitochondria, and are now referred to as 'cryptic'. Cryptic mitochondrion-derived organelles can be classified as either hydrogenosomes or mitosomes. In nearly all cases they lack a genome and all organellar proteins are nucleus-encoded and expressed in the cytosol. The same is true for the majority of proteins in canonical mitochondria, where the proteins are directed to the organelle by specific targeting sequences (transit peptides) that are recognised by translocases in the mitochondrial membrane. In this review, we compare targeting sequences of different parasitic systems with highly reduced mitochondria and give an overview of how the import machinery has been modified in hydrogenosomes and mitosomes.
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Affiliation(s)
- Lena Burri
- Canadian Institute for Advanced Research, Department of Botany, University of British Columbia, 3529-6270 University Boulevard, Vancouver, BC, Canada V6T 1Z4
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Embley TM. Multiple secondary origins of the anaerobic lifestyle in eukaryotes. Philos Trans R Soc Lond B Biol Sci 2006; 361:1055-67. [PMID: 16754614 PMCID: PMC1578728 DOI: 10.1098/rstb.2006.1844] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Classical ideas for early eukaryotic evolution often posited a period of anaerobic evolution producing a nucleated phagocytic cell to engulf the mitochondrial endosymbiont, whose presence allowed the host to colonize emerging aerobic environments. This idea was given credence by the existence of contemporary anaerobic eukaryotes that were thought to primitively lack mitochondria, thus providing examples of the type of host cell needed. However, the groups key to this hypothesis have now been shown to contain previously overlooked mitochondrial homologues called hydrogenosomes or mitosomes; organelles that share common ancestry with mitochondria but which do not carry out aerobic respiration. Mapping these data on the unfolding eukaryotic tree reveals that secondary adaptation to anaerobic habitats is a reoccurring theme among eukaryotes. The apparent ubiquity of mitochondrial homologues bears testament to the importance of the mitochondrial endosymbiosis, perhaps as a founding event, in eukaryotic evolution. Comparative study of different mitochondrial homologues is needed to determine their fundamental importance for contemporary eukaryotic cells.
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Affiliation(s)
- T Martin Embley
- The Devonshire Building, University of Newcastle upon Tyne, Division of Biology, NE1 7RU, UK.
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Hackstein JHP, Tjaden J, Huynen M. Mitochondria, hydrogenosomes and mitosomes: products of evolutionary tinkering! Curr Genet 2006; 50:225-45. [PMID: 16897087 DOI: 10.1007/s00294-006-0088-8] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2006] [Revised: 06/29/2006] [Accepted: 07/02/2006] [Indexed: 11/29/2022]
Affiliation(s)
- Johannes H P Hackstein
- Department of Evolutionary Microbiology, Faculty of Science, Radboud University Nijmegen, Toernooiveld 1, 6525, ED Nijmegen, The Netherlands.
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Abstract
Complete or partial genome sequences have recently become available for several medically and evolutionarily important parasitic protozoa. Through the application of bioinformatics complete metabolic repertoires for these parasites can be predicted. For experimentally intractable parasites insight provided by metabolic maps generated in silico has been startling. At its more extreme end, such bioinformatics reckoning facilitated the discovery in some parasites of mitochondria remodelled beyond previous recognition, and the identification of a non-photosynthetic chloroplast relic in malarial parasites. However, for experimentally tractable parasites, mapping of the general metabolic terrain is only a first step in understanding how the parasite modulates its streamlined, yet still often puzzlingly complex, metabolism in order to complete life cycles within host, vector, or environment. This review provides a comparative overview and discussion of metabolic strategies used by several different parasitic protozoa in order to subvert and survive host defences, and illustrates how genomic data contribute to the elucidation of parasite metabolism.
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Affiliation(s)
- Michael L Ginger
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
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41
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Dacks JB, Dyal PL, Embley TM, van der Giezen M. Hydrogenosomal succinyl-CoA synthetase from the rumen-dwelling fungus Neocallimastix patriciarum; an energy-producing enzyme of mitochondrial origin. Gene 2006; 373:75-82. [PMID: 16515848 DOI: 10.1016/j.gene.2006.01.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2005] [Revised: 12/19/2005] [Accepted: 01/10/2006] [Indexed: 10/25/2022]
Abstract
Hydrogenosomes are hydrogen-producing organelles that are related to mitochondria and found in a variety of evolutionarily unrelated anaerobic microbial eukaryotes. Similar to classic mitochondria, hydrogenosomes contain the enzyme catalyzing the only reaction of the citric acid cycle directly producing energy; succinyl-CoA synthetase. We have isolated and characterized the genes encoding both subunits of this enzyme from the anaerobic chytrid fungus Neocallimastix patriciarum, a model organism in hydrogenosome research. Both subunits contain all characteristic features of this enzyme, including predicted hydrogenosomal targeting signals. Phylogenetic analyses of succinyl-CoA synthetase clearly indicate its mitochondrial ancestry, both by affiliation with mitochondrially localized fungal homologues and by the sisterhood of the eukaryotic succinyl-CoA synthetase clade with alpha-proteobacteria. Our analyses of the Trichomonas vaginalis SCS sequences also confirmed the mitochondrial affiliation of these hydrogenosomal enzymes, in contrast to previous results. While both hydrogenosomal and mitochondrial succinyl-CoA synthetase homologues have been identified, no succinyl-CoA synthetase proteins were identifiable in taxa possessing another mitochondrially derived organelle, the mitosome. Our analyses further confirm the mitochondrial ancestry of the Neocallimastix hydrogenosome and sheds light upon the stepwise process by which mitochondria evolve into alternate forms of the organelle.
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Affiliation(s)
- Joel B Dacks
- Department of Zoology, the Natural History Museum, Cromwell Road, London SW7 5BD, UK
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42
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Abstract
The idea that some eukaryotes primitively lacked mitochondria and were true intermediates in the prokaryote-to-eukaryote transition was an exciting prospect. It spawned major advances in understanding anaerobic and parasitic eukaryotes and those with previously overlooked mitochondria. But the evolutionary gap between prokaryotes and eukaryotes is now deeper, and the nature of the host that acquired the mitochondrion more obscure, than ever before.
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Affiliation(s)
- T Martin Embley
- School of Biology, The Devonshire Building, University of Newcastle upon Tyne, Newcastle NE1 7RU, UK.
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Bullerwell CE, Lang BF. Fungal evolution: the case of the vanishing mitochondrion. Curr Opin Microbiol 2005; 8:362-9. [PMID: 15993645 DOI: 10.1016/j.mib.2005.06.009] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2005] [Accepted: 06/20/2005] [Indexed: 11/18/2022]
Abstract
Mitochondria, the energy-producing organelles of the eukaryotic cell, are derived from an ancient endosymbiotic alpha-Proteobacterium. These organelles contain their own genetic system, a remnant of the endosymbiont's genome, which encodes only a fraction of the mitochondrial proteome. The majority of mitochondrial proteins are translated from nuclear genes and are imported into mitochondria. Recent studies of phylogenetically diverse representatives of Fungi reveal that their mitochondrial DNAs are among the most highly derived, encoding only a limited set of genes. Much of the reduction in the coding content of the mitochondrial genome probably occurred early in fungal evolution. Nevertheless, genome reduction is an ongoing process. Fungi in the chytridiomycete order Neocallimastigales and in the pathogenic Microsporidia have taken mitochondrial reduction to the extreme and have permanently lost a mitochondrial genome. These organisms have organelles derived from mitochondria that retain traces of their mitochondrial ancestry.
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Affiliation(s)
- Charles E Bullerwell
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, B3H 1X5, Canada
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van der Giezen M, Tovar J. Degenerate mitochondria. EMBO Rep 2005; 6:525-30. [PMID: 15940286 PMCID: PMC1369098 DOI: 10.1038/sj.embor.7400440] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2004] [Accepted: 04/15/2005] [Indexed: 11/08/2022] Open
Abstract
Mitochondria are the main sites of biological energy generation in eukaryotes. These organelles are remnants of a bacterial endosymbiont that took up residence inside a host cell over 1,500 million years ago. Comparative genomics studies suggest that the mitochondrion is monophyletic in origin. Thus, the original mitochondrial endosymbiont has evolved independently in anaerobic and aerobic environments that are inhabited by diverse eukaryotic lineages. This process has resulted in a collection of morphologically, genetically and functionally heterogeneous organelle variants that include anaerobic and aerobic mitochondria, hydrogenosomes and mitosomes. Current studies aim to determine whether a central common function drives the retention of mitochondrial organelles in different eukaryotic organisms.
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Affiliation(s)
- Mark van der Giezen
- School of Biological Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, UK
| | - Jorge Tovar
- School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK
- Tel: + 44 1784 414159; Fax: +44 1784 434326;
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Dolezal P, Smíd O, Rada P, Zubácová Z, Bursać D, Suták R, Nebesárová J, Lithgow T, Tachezy J. Giardia mitosomes and trichomonad hydrogenosomes share a common mode of protein targeting. Proc Natl Acad Sci U S A 2005; 102:10924-9. [PMID: 16040811 PMCID: PMC1182405 DOI: 10.1073/pnas.0500349102] [Citation(s) in RCA: 126] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mitochondria are archetypal organelles of endosymbiotic origin in eukaryotic cells. Some unicellular eukaryotes (protists) were considered to be primarily amitochondrial organisms that diverged from the eukaryotic lineage before the acquisition of the premitochondrial endosymbiont, but their amitochondrial status was recently challenged by the discovery of mitochondria-like double membrane-bound organelles called mitosomes. Here, we report that proteins targeted into mitosomes of Giardia intestinalis have targeting signals necessary and sufficient to be recognized by the mitosomal protein import machinery. Expression of these mitosomal proteins in Trichomonas vaginalis results in targeting to hydrogenosomes, a hydrogen-producing form of mitochondria. We identify, in Giardia and Trichomonas, proteins related to the component of the translocase in the inner membrane from mitochondria and the processing peptidase. A shared mode of protein targeting supports the hypothesis that mitosomes, hydrogenosomes, and mitochondria represent different forms of the same fundamental organelle having evolved under distinct selection pressures.
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Affiliation(s)
- Pavel Dolezal
- Department of Parasitology, Charles University, Vinicna 7, 128 44 Prague 2, Czech Republic
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Boxma B, de Graaf RM, van der Staay GWM, van Alen TA, Ricard G, Gabaldón T, van Hoek AHAM, Moon-van der Staay SY, Koopman WJH, van Hellemond JJ, Tielens AGM, Friedrich T, Veenhuis M, Huynen MA, Hackstein JHP. An anaerobic mitochondrion that produces hydrogen. Nature 2005; 434:74-9. [PMID: 15744302 DOI: 10.1038/nature03343] [Citation(s) in RCA: 156] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2004] [Accepted: 01/07/2005] [Indexed: 11/09/2022]
Abstract
Hydrogenosomes are organelles that produce ATP and hydrogen, and are found in various unrelated eukaryotes, such as anaerobic flagellates, chytridiomycete fungi and ciliates. Although all of these organelles generate hydrogen, the hydrogenosomes from these organisms are structurally and metabolically quite different, just like mitochondria where large differences also exist. These differences have led to a continuing debate about the evolutionary origin of hydrogenosomes. Here we show that the hydrogenosomes of the anaerobic ciliate Nyctotherus ovalis, which thrives in the hindgut of cockroaches, have retained a rudimentary genome encoding components of a mitochondrial electron transport chain. Phylogenetic analyses reveal that those proteins cluster with their homologues from aerobic ciliates. In addition, several nucleus-encoded components of the mitochondrial proteome, such as pyruvate dehydrogenase and complex II, were identified. The N. ovalis hydrogenosome is sensitive to inhibitors of mitochondrial complex I and produces succinate as a major metabolic end product--biochemical traits typical of anaerobic mitochondria. The production of hydrogen, together with the presence of a genome encoding respiratory chain components, and biochemical features characteristic of anaerobic mitochondria, identify the N. ovalis organelle as a missing link between mitochondria and hydrogenosomes.
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Affiliation(s)
- Brigitte Boxma
- Department of Evolutionary Microbiology, Faculty of Science, Radboud University Nijmegen, Toernooiveld 1, NL-6525 ED Nijmegen, The Netherlands
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Gabaldón T, Huynen MA. Shaping the mitochondrial proteome. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2005; 1659:212-20. [PMID: 15576054 DOI: 10.1016/j.bbabio.2004.07.011] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 06/04/2004] [Revised: 07/15/2004] [Accepted: 07/28/2004] [Indexed: 10/26/2022]
Abstract
Mitochondria are eukaryotic organelles that originated from a single bacterial endosymbiosis some 2 billion years ago. The transition from the ancestral endosymbiont to the modern mitochondrion has been accompanied by major changes in its protein content, the so-called proteome. These changes included complete loss of some bacterial pathways, amelioration of others and gain of completely new complexes of eukaryotic origin such as the ATP/ADP translocase and most of the mitochondrial protein import machinery. This renewal of proteins has been so extensive that only 14-16% of modern mitochondrial proteome has an origin that can be traced back to the bacterial endosymbiont. The rest consists of proteins of diverse origin that were eventually recruited to function in the organelle. This shaping of the proteome content reflects the transformation of mitochondria into a highly specialized organelle that, besides ATP production, comprises a variety of functions within the eukaryotic metabolism. Here we review recent advances in the fields of comparative genomics and proteomics that are throwing light on the origin and evolution of the mitochondrial proteome.
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Affiliation(s)
- Toni Gabaldón
- NCMLS, Nijmegen Center for Molecular Life Sciences, P/O: CMBI, Center for Molecular and Biomolecular Informatics, University of Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands.
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Mentel M, Piskur J, Neuvéglise C, Rycovská A, Cellengová G, Kolarov J. Triplicate genes for mitochondrial ADP/ATP carriers in the aerobic yeast Yarrowia lipolytica are regulated differentially in the absence of oxygen. Mol Genet Genomics 2005; 273:84-91. [PMID: 15688220 DOI: 10.1007/s00438-005-1107-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2004] [Accepted: 01/07/2005] [Indexed: 11/24/2022]
Abstract
Yarrowia lipolytica is a strictly aerobic fungus, which differs from the extensively studied model yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe with respect to its physiology, genetics and dimorphic growth habit. We isolated and sequenced cDNA and genomic clones (YlAAC1) from Y. lipolytica that encode a mitochondrial ADP/ATP carrier. The YlAAC1 gene can complement the S. cerevisiae Deltaaac2 deletion mutant. Southern hybridization, analysis of Yarrowia clones obtained in the course of the Genolevures project, and further sequencing revealed the existence of two paralogs of the YlAAC1 gene, which were named YlAAC2 and YlAAC3, respectively. Phylogenetic analysis showed that YlAAC1 and YlAAC2 were more closely related to each other than to YlAAC3, and are likely to represent the products of a recent gene duplication. All three Y. lipolytica YlAAC genes group together on the phylogenetic tree, suggesting that YlAAC3 is derived from a more ancient duplication within the Y. lipolytica lineage. A similar branching pattern for the three ScAAC paralogs in the facultative anaerobe S. cerevisiae demonstrates that two rounds of duplication of AAC genes occurred independently at least twice in the evolution of hemiascomycetous yeasts. Surprisingly, in both the aerobic Y. lipolytica and the facultative anaerobe S. cerevisiae, the three paralogs are differentially regulated in the absence of oxygen. Apparently, Y. lipolytica can sense hypoxia and down-regulate target genes in response.
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Affiliation(s)
- Marek Mentel
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University, Mlynska dolina CH-I, 842 15 Bratislava, Slovakia
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van der Giezen M, Tovar J, Clark CG. Mitochondrion‐Derived Organelles in Protists and Fungi. INTERNATIONAL REVIEW OF CYTOLOGY 2005; 244:175-225. [PMID: 16157181 DOI: 10.1016/s0074-7696(05)44005-x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
The mitochondrion is generally considered to be a defining feature of eukaryotic cells, yet most anaerobic eukaryotes lack this organelle. Many of these were previously thought to derive from eukaryotes that diverged prior to acquisition of the organelle through endosymbiosis. It is now known that all extant eukaryotes are descended from an ancestor that had a mitochondrion and that in anaerobic eukaryotes the organelle has been modified into either hydrogenosomes, which continue to generate energy for the host cell, or mitosomes, which do not. These organelles have each arisen independently several times. Recent evidence suggests a shared derived characteristic that may be responsible for the retention of the organelles in the absence of the better-known mitochondrial functions--iron-sulfur cluster assembly. This review explores the events leading to this new understanding of mitochondrion-derived organelles in amitochondriate eukaryotes, the current state of our knowledge, and future areas for investigation.
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Affiliation(s)
- Mark van der Giezen
- School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey TW20 0EX, United Kingdom
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50
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Hackstein JHP, Yarlett N. Hydrogenosomes and symbiosis. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2005; 41:117-42. [PMID: 16623392 DOI: 10.1007/3-540-28221-1_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Johannes H P Hackstein
- Department of Evolutionary Microbiology, Faculty of Science, Radboud University Nijmegen, Toernooiveld 1, NL 6525 ED Nijmegen, The Netherlands.
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