1
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Araiso Y, Imai K, Endo T. Role of the TOM Complex in Protein Import into Mitochondria: Structural Views. Annu Rev Biochem 2022; 91:679-703. [PMID: 35287471 DOI: 10.1146/annurev-biochem-032620-104527] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mitochondria are central to energy production, metabolism and signaling, and apoptosis. To make new mitochondria from preexisting mitochondria, the cell needs to import mitochondrial proteins from the cytosol into the mitochondria with the aid of translocators in the mitochondrial membranes. The translocase of the outer membrane (TOM) complex, an outer membrane translocator, functions as an entry gate for most mitochondrial proteins. Although high-resolution structures of the receptor subunits of the TOM complex were deposited in the early 2000s, those of entire TOM complexes became available only in 2019. The structural details of these TOM complexes, consisting of the dimer of the β-barrel import channel Tom40 and four α-helical membrane proteins, revealed the presence of several distinct paths and exits for the translocation of over 1,000 different mitochondrial precursor proteins. High-resolution structures of TOM complexes now open up a new era of studies on the structures, functions, and dynamics of the mitochondrial import system. Expected final online publication date for the Annual Review of Biochemistry, Volume 91 is June 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Yuhei Araiso
- Department of Clinical Laboratory Science, Division of Health Sciences, Graduate School of Medical Science, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Kenichiro Imai
- Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tokyo, Japan
| | - Toshiya Endo
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, Japan; .,Institute for Protein Dynamics, Kyoto Sangyo University, Kyoto, Japan
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2
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Kreimendahl S, Rassow J. The Mitochondrial Outer Membrane Protein Tom70-Mediator in Protein Traffic, Membrane Contact Sites and Innate Immunity. Int J Mol Sci 2020; 21:E7262. [PMID: 33019591 PMCID: PMC7583919 DOI: 10.3390/ijms21197262] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 09/25/2020] [Accepted: 09/28/2020] [Indexed: 02/08/2023] Open
Abstract
Tom70 is a versatile adaptor protein of 70 kDa anchored in the outer membrane of mitochondria in metazoa, fungi and amoeba. The tertiary structure was resolved for the Tom70 of yeast, showing 26 α-helices, most of them participating in the formation of 11 tetratricopeptide repeat (TPR) motifs. Tom70 serves as a docking site for cytosolic chaperone proteins and co-chaperones and is thereby involved in the uptake of newly synthesized chaperone-bound proteins in mitochondrial biogenesis. In yeast, Tom70 additionally mediates ER-mitochondria contacts via binding to sterol transporter Lam6/Ltc1. In mammalian cells, TOM70 promotes endoplasmic reticulum (ER) to mitochondria Ca2+ transfer by association with the inositol-1,4,5-triphosphate receptor type 3 (IP3R3). TOM70 is specifically targeted by the Bcl-2-related protein MCL-1 that acts as an anti-apoptotic protein in macrophages infected by intracellular pathogens, but also in many cancer cells. By participating in the recruitment of PINK1 and the E3 ubiquitin ligase Parkin, TOM70 can be implicated in the development of Parkinson's disease. TOM70 acts as receptor of the mitochondrial antiviral-signaling protein (MAVS) and thereby participates in the corresponding system of innate immunity against viral infections. The protein encoded by Orf9b in the genome of SARS-CoV-2 binds to TOM70, probably compromising the synthesis of type I interferons.
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Affiliation(s)
| | - Joachim Rassow
- Institute for Biochemistry and Pathobiochemistry, Ruhr-University Bochum, 44801 Bochum, Germany;
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3
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Makki A, Rada P, Žárský V, Kereïche S, Kováčik L, Novotný M, Jores T, Rapaport D, Tachezy J. Triplet-pore structure of a highly divergent TOM complex of hydrogenosomes in Trichomonas vaginalis. PLoS Biol 2019; 17:e3000098. [PMID: 30608924 PMCID: PMC6334971 DOI: 10.1371/journal.pbio.3000098] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 01/16/2019] [Accepted: 12/11/2018] [Indexed: 11/30/2022] Open
Abstract
Mitochondria originated from proteobacterial endosymbionts, and their transition to organelles was tightly linked to establishment of the protein import pathways. The initial import of most proteins is mediated by the translocase of the outer membrane (TOM). Although TOM is common to all forms of mitochondria, an unexpected diversity of subunits between eukaryotic lineages has been predicted. However, experimental knowledge is limited to a few organisms, and so far, it remains unsettled whether the triplet-pore or the twin-pore structure is the generic form of TOM complex. Here, we analysed the TOM complex in hydrogenosomes, a metabolically specialised anaerobic form of mitochondria found in the excavate Trichomonas vaginalis. We demonstrate that the highly divergent β-barrel T. vaginalis TOM (TvTom)40-2 forms a translocation channel to conduct hydrogenosomal protein import. TvTom40-2 is present in high molecular weight complexes, and their analysis revealed the presence of four tail-anchored (TA) proteins. Two of them, Tom36 and Tom46, with heat shock protein (Hsp)20 and tetratricopeptide repeat (TPR) domains, can bind hydrogenosomal preproteins and most likely function as receptors. A third subunit, Tom22-like protein, has a short cis domain and a conserved Tom22 transmembrane segment but lacks a trans domain. The fourth protein, hydrogenosomal outer membrane protein 19 (Homp19) has no known homology. Furthermore, our data indicate that TvTOM is associated with sorting and assembly machinery (Sam)50 that is involved in β-barrel assembly. Visualisation of TvTOM by electron microscopy revealed that it forms three pores and has an unconventional skull-like shape. Although TvTOM seems to lack Tom7, our phylogenetic profiling predicted Tom7 in free-living excavates. Collectively, our results suggest that the triplet-pore TOM complex, composed of three conserved subunits, was present in the last common eukaryotic ancestor (LECA), while receptors responsible for substrate binding evolved independently in different eukaryotic lineages. The highly divergent outer membrane translocase (TOM) from the Trichomonas hydrogenosome (an organelle related to mitochondria) is composed of conserved core and lineage-specific subunits, and has an unconventional skull-like triplet-pore structure. Mitochondria carry out many vital functions in the eukaryotic cells, from energy metabolism to programmed cell death. These organelles descended from bacterial endosymbionts, and during their evolution, the cell established a mechanism to transport nuclear-encoded proteins into mitochondria. Embedded in the mitochondrial outer membrane is a molecular machine, known as the translocase of the outer membrane (TOM) complex, that plays a key role in protein import and biogenesis of the organelle. Here, we provide evidence that the TOM complex of hydrogenosomes, a metabolically specialised anaerobic form of mitochondria in Trichomonas vaginalis, is composed of highly divergent core subunits and lineage-specific peripheral subunits. Despite the evolutionary distance, the T. vaginalis TOM (TvTOM) complex has a conserved triplet-pore structure but with a unique skull-like shape suggesting that the TOM in the early mitochondrion could have formed three pores. Our results contribute to a better understanding of the evolution and adaptation of protein import machinery in anaerobic forms of mitochondria.
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Affiliation(s)
- Abhijith Makki
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Prague, Czech Republic
| | - Petr Rada
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Prague, Czech Republic
| | - Vojtěch Žárský
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Prague, Czech Republic
| | - Sami Kereïche
- Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Lubomír Kováčik
- Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Marian Novotný
- Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Tobias Jores
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Doron Rapaport
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Jan Tachezy
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Prague, Czech Republic
- * E-mail:
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4
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Harsman A, Schneider A. Mitochondrial protein import in trypanosomes: Expect the unexpected. Traffic 2017; 18:96-109. [PMID: 27976830 DOI: 10.1111/tra.12463] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 12/01/2016] [Accepted: 12/06/2016] [Indexed: 12/11/2022]
Abstract
Mitochondria have many different functions, the most important one of which is oxidative phosphorylation. They originated from an endosymbiotic event between a bacterium and an archaeal host cell. It was the evolution of a protein import system that marked the boundary between the endosymbiotic ancestor of the mitochondrion and a true organelle that is under the control of the nucleus. In present day mitochondria more than 95% of all proteins are imported from the cytosol in a proces mediated by hetero-oligomeric protein complexes in the outer and inner mitochondrial membranes. In this review we compare mitochondrial protein import in the best studied model system yeast and the parasitic protozoan Trypanosoma brucei. The 2 organisms are phylogenetically only remotely related. Despite the fact that mitochondrial protein import has the same function in both species, only very few subunits of their import machineries are conserved. Moreover, while yeast has 2 inner membrane protein translocases, one specialized for presequence-containing and one for mitochondrial carrier proteins, T. brucei has a single inner membrane translocase only, that mediates import of both types of substrates. The evolutionary implications of these findings are discussed.
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Affiliation(s)
- Anke Harsman
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
| | - André Schneider
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
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5
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Abstract
Mitochondrion-related organelles (MROs) have arisen independently in a wide range of anaerobic protist lineages. Only a few of these organelles and their functions have been investigated in detail, and most of what is known about MROs comes from studies of parasitic organisms such as the parabasalid Trichomonas vaginalis. Here, we describe the MRO of a free-living anaerobic jakobid excavate, Stygiella incarcerata. We report an RNAseq-based reconstruction of S. incarcerata’s MRO proteome, with an associated biochemical map of the pathways predicted to be present in this organelle. The pyruvate metabolism and oxidative stress response pathways are strikingly similar to those found in the MROs of other anaerobic protists, such as Pygsuia and Trichomonas. This elegant example of convergent evolution is suggestive of an anaerobic biochemical ‘module’ of prokaryotic origins that has been laterally transferred among eukaryotes, enabling them to adapt rapidly to anaerobiosis. We also identified genes corresponding to a variety of mitochondrial processes not found in Trichomonas, including intermembrane space components of the mitochondrial protein import apparatus, and enzymes involved in amino acid metabolism and cardiolipin biosynthesis. In this respect, the MROs of S. incarcerata more closely resemble those of the much more distantly related free-living organisms Pygsuia biforma and Cantina marsupialis, likely reflecting these organisms’ shared lifestyle as free-living anaerobes.
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Affiliation(s)
- Michelle M Leger
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada
| | - Laura Eme
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada
| | - Laura A Hug
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada
| | - Andrew J Roger
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada
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6
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Mani J, Meisinger C, Schneider A. Peeping at TOMs-Diverse Entry Gates to Mitochondria Provide Insights into the Evolution of Eukaryotes. Mol Biol Evol 2015; 33:337-51. [PMID: 26474847 DOI: 10.1093/molbev/msv219] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Mitochondria are essential for eukaryotic life and more than 95% of their proteins are imported as precursors from the cytosol. The targeting signals for this posttranslational import are conserved in all eukaryotes. However, this conservation does not hold true for the protein translocase of the mitochondrial outer membrane that serves as entry gate for essentially all precursor proteins. Only two of its subunits, Tom40 and Tom22, are conserved and thus likely were present in the last eukaryotic common ancestor. Tom7 is found in representatives of all supergroups except the Excavates. This suggests that it was added to the core of the translocase after the Excavates segregated from all other eukaryotes. A comparative analysis of the biochemically and functionally characterized outer membrane translocases of yeast, plants, and trypanosomes, which represent three eukaryotic supergroups, shows that the receptors that recognize the conserved import signals differ strongly between the different systems. They present a remarkable example of convergent evolution at the molecular level. The structural diversity of the functionally conserved import receptors therefore provides insight into the early evolutionary history of mitochondria.
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Affiliation(s)
- Jan Mani
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
| | - Chris Meisinger
- Institut für Biochemie und Molekularbiologie, ZBMZ and BIOSS Centre for Biological Signalling Studies, Universität Freiburg, Freiburg, Germany
| | - André Schneider
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
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7
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Wojtkowska M, Buczek D, Stobienia O, Karachitos A, Antoniewicz M, Slocinska M, Makałowski W, Kmita H. The TOM Complex of Amoebozoans: the Cases of the Amoeba Acanthamoeba castellanii and the Slime Mold Dictyostelium discoideum. Protist 2015; 166:349-62. [PMID: 26074248 DOI: 10.1016/j.protis.2015.05.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 05/10/2015] [Accepted: 05/14/2015] [Indexed: 11/29/2022]
Abstract
Protein import into mitochondria requires a wide variety of proteins, forming complexes in both mitochondrial membranes. The TOM complex (translocase of the outer membrane) is responsible for decoding of targeting signals, translocation of imported proteins across or into the outer membrane, and their subsequent sorting. Thus the TOM complex is regarded as the main gate into mitochondria for imported proteins. Available data indicate that mitochondria of representative organisms from across the major phylogenetic lineages of eukaryotes differ in subunit organization of the TOM complex. The subunit organization of the TOM complex in the Amoebozoa is still elusive, so we decided to investigate its organization in the soil amoeba Acanthamoeba castellanii and the slime mold Dictyostelium discoideum. They represent two major subclades of the Amoebozoa: the Lobosa and Conosa, respectively. Our results confirm the presence of Tom70, Tom40 and Tom7 in the A. castellanii and D. discoideum TOM complex, while the presence of Tom22 and Tom20 is less supported. Interestingly, the Tom proteins display the highest similarity to Opisthokonta cognate proteins, with the exception of Tom40. Thus representatives of two major subclades of the Amoebozoa appear to be similar in organization of the TOM complex, despite differences in their lifestyle.
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Affiliation(s)
- Małgorzata Wojtkowska
- Adam Mickiewicz University, Faculty of Biology, Institute of Molecular Biology and Biotechnology, Department of Bioenergetics, Poznań, Poland.
| | - Dorota Buczek
- Adam Mickiewicz University, Faculty of Biology, Institute of Molecular Biology and Biotechnology, Department of Bioenergetics, Poznań, Poland; University of Muenster, Faculty of Medicine Institute of Bioinformatics, Muenster, Germany
| | - Olgierd Stobienia
- Adam Mickiewicz University, Faculty of Biology, Institute of Molecular Biology and Biotechnology, Department of Bioenergetics, Poznań, Poland
| | - Andonis Karachitos
- Adam Mickiewicz University, Faculty of Biology, Institute of Molecular Biology and Biotechnology, Department of Bioenergetics, Poznań, Poland
| | - Monika Antoniewicz
- Adam Mickiewicz University, Faculty of Biology, Institute of Molecular Biology and Biotechnology, Department of Bioenergetics, Poznań, Poland
| | - Małgorzata Slocinska
- Adam Mickiewicz University, Faculty of Biology, Institute of Experimental Biology, Department of Animal Physiology and Development, Poznań, Poland
| | - Wojciech Makałowski
- University of Muenster, Faculty of Medicine Institute of Bioinformatics, Muenster, Germany
| | - Hanna Kmita
- Adam Mickiewicz University, Faculty of Biology, Institute of Molecular Biology and Biotechnology, Department of Bioenergetics, Poznań, Poland
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Mani J, Desy S, Niemann M, Chanfon A, Oeljeklaus S, Pusnik M, Schmidt O, Gerbeth C, Meisinger C, Warscheid B, Schneider A. Mitochondrial protein import receptors in Kinetoplastids reveal convergent evolution over large phylogenetic distances. Nat Commun 2015; 6:6646. [PMID: 25808593 PMCID: PMC4389251 DOI: 10.1038/ncomms7646] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 02/13/2015] [Indexed: 11/09/2022] Open
Abstract
Mitochondrial protein import is essential for all eukaryotes and mediated by hetero-oligomeric protein translocases thought to be conserved within all eukaryotes. We have identified and analysed the function and architecture of the non-conventional outer membrane (OM) protein translocase in the early diverging eukaryote Trypanosoma brucei. It consists of six subunits that show no obvious homology to translocase components of other species. Two subunits are import receptors that have a unique topology and unique protein domains and thus evolved independently of the prototype receptors Tom20 and Tom70. Our study suggests that protein import receptors were recruited to the core of the OM translocase after the divergence of the major eukaryotic supergroups. Moreover, it links the evolutionary history of mitochondrial protein import receptors to the origin of the eukaryotic supergroups.
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Affiliation(s)
- Jan Mani
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern CH-3012, Switzerland
| | - Silvia Desy
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern CH-3012, Switzerland
| | - Moritz Niemann
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern CH-3012, Switzerland
| | - Astrid Chanfon
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern CH-3012, Switzerland
| | - Silke Oeljeklaus
- Department of Biochemistry and Functional Proteomics, Faculty of Biology and BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg 79104, Germany
| | - Mascha Pusnik
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern CH-3012, Switzerland
| | - Oliver Schmidt
- Institut für Biochemie und Molekularbiologie, ZBMZ and BIOSS Centre for Biological Signalling Studies, Universität Freiburg, Freiburg 79104, Germany
| | - Carolin Gerbeth
- Institut für Biochemie und Molekularbiologie, ZBMZ and BIOSS Centre for Biological Signalling Studies, Universität Freiburg, Freiburg 79104, Germany
| | - Chris Meisinger
- Institut für Biochemie und Molekularbiologie, ZBMZ and BIOSS Centre for Biological Signalling Studies, Universität Freiburg, Freiburg 79104, Germany
| | - Bettina Warscheid
- Department of Biochemistry and Functional Proteomics, Faculty of Biology and BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg 79104, Germany
| | - André Schneider
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern CH-3012, Switzerland
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9
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Highly divergent mitochondrion-related organelles in anaerobic parasitic protozoa. Biochimie 2014; 100:3-17. [DOI: 10.1016/j.biochi.2013.11.018] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Accepted: 11/24/2013] [Indexed: 11/20/2022]
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10
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Novel TPR-containing subunit of TOM complex functions as cytosolic receptor for Entamoeba mitosomal transport. Sci Rep 2013; 3:1129. [PMID: 23350036 PMCID: PMC3553487 DOI: 10.1038/srep01129] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 12/27/2012] [Indexed: 11/24/2022] Open
Abstract
Under anaerobic environments, the mitochondria have undergone remarkable reduction and transformation into highly reduced structures, referred as mitochondrion-related organelles (MROs), which include mitosomes and hydrogenosomes. In agreement with the concept of reductive evolution, mitosomes of Entamoeba histolytica lack most of the components of the TOM (translocase of the outer mitochondrial membrane) complex, which is required for the targeting and membrane translocation of preproteins into the canonical aerobic mitochondria. Here we showed, in E. histolytica mitosomes, the presence of a 600-kDa TOM complex composed of Tom40, a conserved pore-forming subunit, and Tom60, a novel lineage-specific receptor protein. Tom60, containing multiple tetratricopeptide repeats, is localized to the mitosomal outer membrane and the cytosol, and serves as a receptor of both mitosomal matrix and membrane preproteins. Our data indicate that Entamoeba has invented a novel lineage-specific shuttle receptor of the TOM complex as a consequence of adaptation to an anaerobic environment.
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11
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Pusnik M, Mani J, Schmidt O, Niemann M, Oeljeklaus S, Schnarwiler F, Warscheid B, Lithgow T, Meisinger C, Schneider A. An essential novel component of the noncanonical mitochondrial outer membrane protein import system of trypanosomatids. Mol Biol Cell 2012; 23:3420-8. [PMID: 22787278 PMCID: PMC3431924 DOI: 10.1091/mbc.e12-02-0107] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The mitochondrial outer membrane protein Tom40 is the general entry gate for imported proteins in essentially all eukaryotes. Trypanosomatids lack Tom40, however, and use instead a protein termed the archaic translocase of the outer mitochondrial membrane (ATOM). Here we report the discovery of pATOM36, a novel essential component of the trypanosomal outer membrane protein import system that interacts with ATOM. pATOM36 is not related to known Tom proteins from other organisms and mediates the import of matrix proteins. However, there is a group of precursor proteins whose import is independent of pATOM36. Domain-swapping experiments indicate that the N-terminal presequence-containing domain of the substrate proteins at least in part determines the dependence on pATOM36. Secondary structure profiling suggests that pATOM36 is composed largely of α-helices and its assembly into the outer membrane is independent of the sorting and assembly machinery complex. Taken together, these results show that pATOM36 is a novel component associated with the ATOM complex that promotes the import of a subpopulation of proteins into the mitochondrial matrix.
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Affiliation(s)
- Mascha Pusnik
- Department of Chemistry and Biochemistry, University of Bern, CH-3012 Bern, Switzerland
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12
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Evolution of Fe/S cluster biogenesis in the anaerobic parasite Blastocystis. Proc Natl Acad Sci U S A 2012; 109:10426-31. [PMID: 22699510 DOI: 10.1073/pnas.1116067109] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Iron/sulfur cluster (ISC)-containing proteins are essential components of cells. In most eukaryotes, Fe/S clusters are synthesized by the mitochondrial ISC machinery, the cytosolic iron/sulfur assembly system, and, in photosynthetic species, a plastid sulfur-mobilization (SUF) system. Here we show that the anaerobic human protozoan parasite Blastocystis, in addition to possessing ISC and iron/sulfur assembly systems, expresses a fused version of the SufC and SufB proteins of prokaryotes that it has acquired by lateral transfer from an archaeon related to the Methanomicrobiales, an important lineage represented in the human gastrointestinal tract microbiome. Although components of the Blastocystis ISC system function within its anaerobic mitochondrion-related organelles and can functionally replace homologues in Trypanosoma brucei, its SufCB protein has similar biochemical properties to its prokaryotic homologues, functions within the parasite's cytosol, and is up-regulated under oxygen stress. Blastocystis is unique among eukaryotic pathogens in having adapted to its parasitic lifestyle by acquiring a SUF system from nonpathogenic Archaea to synthesize Fe/S clusters under oxygen stress.
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13
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Lin L, Pan G, Li T, Dang X, Deng Y, Ma C, Chen J, Luo J, Zhou Z. The protein import pore Tom40 in the microsporidian Nosema bombycis. J Eukaryot Microbiol 2012; 59:251-7. [PMID: 22486892 DOI: 10.1111/j.1550-7408.2012.00618.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Revised: 12/11/2012] [Accepted: 12/09/2012] [Indexed: 11/28/2022]
Abstract
Microsporidia, an unusual group of unicellular parasites related to fungi, possess a highly reduced mitochondrion known as the mitosome. Since mitosomes lack an organellar genome, their proteins must be translated in the cytosol before being imported into the mitosome via translocases. We have identified a Tom40 gene (NbTom40), the main component of the translocase of the outer mitochondrial membrane, in the genome of the microsporidian Nosema bombycis. NbTom40 is reduced in size, but it is predicted to form a β-barrel structure composed of 19 β-strands. Phylogenetic analysis confirms that NbTom40 forms a clade with Tom40 sequences from other species, distinct from a related clade of voltage-dependent anion channels (VDACs). The NbTom40 contains a β-signal motif that the polar residue is substituted by glycine. Furthermore, we show that expression of NbTom40, as a GFP fusion protein within yeast cells, directs GFP to mitochondria of yeast. These findings suggest that NbTom40 may serve as an import channel of the microsporidian mitosome and facilitate protein translocation into this organelle.
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Affiliation(s)
- Lipeng Lin
- The State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
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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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Delage L, Leblanc C, Nyvall Collén P, Gschloessl B, Oudot MP, Sterck L, Poulain J, Aury JM, Cock JM. In silico survey of the mitochondrial protein uptake and maturation systems in the brown alga Ectocarpus siliculosus. PLoS One 2011; 6:e19540. [PMID: 21611166 PMCID: PMC3097184 DOI: 10.1371/journal.pone.0019540] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Accepted: 03/31/2011] [Indexed: 01/24/2023] Open
Abstract
The acquisition of mitochondria was a key event in eukaryote evolution. The aim of this study was to identify homologues of the components of the mitochondrial protein import machinery in the brown alga Ectocarpus and to use this information to investigate the evolutionary history of this fundamental cellular process. Detailed searches were carried out both for components of the protein import system and for related peptidases. Comparative and phylogenetic analyses were used to investigate the evolution of mitochondrial proteins during eukaryote diversification. Key observations include phylogenetic evidence for very ancient origins for many protein import components (Tim21, Tim50, for example) and indications of differences between the outer membrane receptors that recognize the mitochondrial targeting signals, suggesting replacement, rearrangement and/or emergence of new components across the major eukaryotic lineages. Overall, the mitochondrial protein import components analysed in this study confirmed a high level of conservation during evolution, indicating that most are derived from very ancient, ancestral proteins. Several of the protein import components identified in Ectocarpus, such as Tim21, Tim50 and metaxin, have also been found in other stramenopiles and this study suggests an early origin during the evolution of the eukaryotes.
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Affiliation(s)
- Ludovic Delage
- Université Pierre et Marie Curie, The Marine Plants and Biomolecules Laboratory, UMR 7139, Station Biologique de Roscoff, Roscoff, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7139, Laboratoire International Associé Dispersal and Adaptation in Marine Species, Station Biologique de Roscoff, Roscoff, France
| | - Catherine Leblanc
- Université Pierre et Marie Curie, The Marine Plants and Biomolecules Laboratory, UMR 7139, Station Biologique de Roscoff, Roscoff, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7139, Laboratoire International Associé Dispersal and Adaptation in Marine Species, Station Biologique de Roscoff, Roscoff, France
| | - Pi Nyvall Collén
- Université Pierre et Marie Curie, The Marine Plants and Biomolecules Laboratory, UMR 7139, Station Biologique de Roscoff, Roscoff, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7139, Laboratoire International Associé Dispersal and Adaptation in Marine Species, Station Biologique de Roscoff, Roscoff, France
| | - Bernhard Gschloessl
- Université Pierre et Marie Curie, The Marine Plants and Biomolecules Laboratory, UMR 7139, Station Biologique de Roscoff, Roscoff, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7139, Laboratoire International Associé Dispersal and Adaptation in Marine Species, Station Biologique de Roscoff, Roscoff, France
| | - Marie-Pierre Oudot
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lieven Sterck
- VIB Department of Plant Systems Biology, Ghent University, Ghent, Belgium
| | - Julie Poulain
- Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, Institut de Génomique, Génoscope, Evry, France
- Centre National de la Recherche Scientifique, UMR 8030, Evry, France
- Université d'Evry, Evry, France
| | - Jean-Marc Aury
- Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, Institut de Génomique, Génoscope, Evry, France
- Centre National de la Recherche Scientifique, UMR 8030, Evry, France
- Université d'Evry, Evry, France
| | - J. Mark Cock
- Université Pierre et Marie Curie, The Marine Plants and Biomolecules Laboratory, UMR 7139, Station Biologique de Roscoff, Roscoff, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7139, Laboratoire International Associé Dispersal and Adaptation in Marine Species, Station Biologique de Roscoff, Roscoff, France
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