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Makki A, Kereïche S, Le T, Kučerová J, Rada P, Žárský V, Hrdý I, Tachezy J. A hybrid TIM complex mediates protein import into hydrogenosomes of Trichomonas vaginalis. BMC Biol 2024; 22:130. [PMID: 38825681 PMCID: PMC11145794 DOI: 10.1186/s12915-024-01928-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 05/22/2024] [Indexed: 06/04/2024] Open
Abstract
BACKGROUND Hydrogenosomes are a specific type of mitochondria that have adapted for life under anaerobiosis. Limited availability of oxygen has resulted in the loss of the membrane-associated respiratory chain, and consequently in the generation of minimal inner membrane potential (Δψ), and inefficient ATP synthesis via substrate-level phosphorylation. The changes in energy metabolism are directly linked with the organelle biogenesis. In mitochondria, proteins are imported across the outer membrane via the Translocase of the Outer Membrane (TOM complex), while two Translocases of the Inner Membrane, TIM22, and TIM23, facilitate import to the inner membrane and matrix. TIM23-mediated steps are entirely dependent on Δψ and ATP hydrolysis, while TIM22 requires only Δψ. The character of the hydrogenosomal inner membrane translocase and the mechanism of translocation is currently unknown. RESULTS We report unprecedented modification of TIM in hydrogenosomes of the human parasite Trichomonas vaginalis (TvTIM). We show that the import of the presequence-containing protein into the hydrogenosomal matrix is mediated by the hybrid TIM22-TIM23 complex that includes three highly divergent core components, TvTim22, TvTim23, and TvTim17-like proteins. The hybrid character of the TvTIM is underlined by the presence of both TvTim22 and TvTim17/23, association with small Tim chaperones (Tim9-10), which in mitochondria are known to facilitate the transfer of substrates to the TIM22 complex, and the coupling with TIM23-specific ATP-dependent presequence translocase-associated motor (PAM). Interactome reconstruction based on co-immunoprecipitation (coIP) and mass spectrometry revealed that hybrid TvTIM is formed with the compositional variations of paralogs. Single-particle electron microscopy for the 132-kDa purified TvTIM revealed the presence of a single ring of small Tims complex, while mitochondrial TIM22 complex bears twin small Tims hexamer. TvTIM is currently the only TIM visualized outside of Opisthokonta, which raised the question of which form is prevailing across eukaryotes. The tight association of the hybrid TvTIM with ADP/ATP carriers (AAC) suggests that AAC may directly supply ATP for the protein import since ATP synthesis is limited in hydrogenosomes. CONCLUSIONS The hybrid TvTIM in hydrogenosomes represents an original structural solution that evolved for protein import when Δψ is negligible and remarkable example of evolutionary adaptation to an anaerobic lifestyle.
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Affiliation(s)
- Abhijith Makki
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, 25250, Vestec, Czech Republic
- Present address: Department of Cellular Biochemistry, University Medical Center Göttingen, D-37073, Göttingen, Germany
| | - Sami Kereïche
- Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University, Albertov 4, 12800, Prague 2, Czech Republic
| | - Tien Le
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, 25250, Vestec, Czech Republic
| | - Jitka Kučerová
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, 25250, Vestec, Czech Republic
| | - Petr Rada
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, 25250, Vestec, Czech Republic
| | - Vojtěch Žárský
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Ivan Hrdý
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, 25250, Vestec, Czech Republic
| | - Jan Tachezy
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, 25250, Vestec, Czech Republic.
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2
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von Känel C, Oeljeklaus S, Wenger C, Stettler P, Harsman A, Warscheid B, Schneider A. Intermembrane space-localized TbTim15 is an essential subunit of the single mitochondrial inner membrane protein translocase of trypanosomes. Mol Microbiol 2024; 121:1112-1126. [PMID: 38622999 DOI: 10.1111/mmi.15262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 03/24/2024] [Accepted: 03/25/2024] [Indexed: 04/17/2024]
Abstract
All mitochondria import >95% of their proteins from the cytosol. This process is mediated by protein translocases in the mitochondrial membranes, whose subunits are generally highly conserved. Most eukaryotes have two inner membrane protein translocases (TIMs) that are specialized to import either presequence-containing or mitochondrial carrier proteins. In contrast, the parasitic protozoan Trypanosoma brucei has a single TIM complex consisting of one conserved and five unique subunits. Here, we identify candidates for new subunits of the TIM or the presequence translocase-associated motor (PAM) using a protein-protein interaction network of previously characterized TIM and PAM subunits. This analysis reveals that the trypanosomal TIM complex contains an additional trypanosomatid-specific subunit, designated TbTim15. TbTim15 is associated with the TIM complex, lacks transmembrane domains, and localizes to the intermembrane space. TbTim15 is essential for procyclic and bloodstream forms of trypanosomes. It contains two twin CX9C motifs and mediates import of both presequence-containing and mitochondrial carrier proteins. While the precise function of TbTim15 in mitochondrial protein import is unknown, our results are consistent with the notion that it may function as an import receptor for the non-canonical trypanosomal TIM complex.
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Affiliation(s)
- Corinne von Känel
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
| | - Silke Oeljeklaus
- Faculty of Chemistry and Pharmacy, Biochemistry II, Theodor Boveri-Institute, University of Würzburg, Würzburg, Germany
| | - Christoph Wenger
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
| | - Philip Stettler
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
| | - Anke Harsman
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
| | - Bettina Warscheid
- Faculty of Chemistry and Pharmacy, Biochemistry II, Theodor Boveri-Institute, University of Würzburg, Würzburg, Germany
| | - André Schneider
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
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3
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Kumar R, Islinger M, Worthy H, Carmichael R, Schrader M. The peroxisome: an update on mysteries 3.0. Histochem Cell Biol 2024; 161:99-132. [PMID: 38244103 PMCID: PMC10822820 DOI: 10.1007/s00418-023-02259-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2023] [Indexed: 01/22/2024]
Abstract
Peroxisomes are highly dynamic, oxidative organelles with key metabolic functions in cellular lipid metabolism, such as the β-oxidation of fatty acids and the synthesis of myelin sheath lipids, as well as the regulation of cellular redox balance. Loss of peroxisomal functions causes severe metabolic disorders in humans. Furthermore, peroxisomes also fulfil protective roles in pathogen and viral defence and immunity, highlighting their wider significance in human health and disease. This has sparked increasing interest in peroxisome biology and their physiological functions. This review presents an update and a continuation of three previous review articles addressing the unsolved mysteries of this remarkable organelle. We continue to highlight recent discoveries, advancements, and trends in peroxisome research, and address novel findings on the metabolic functions of peroxisomes, their biogenesis, protein import, membrane dynamics and division, as well as on peroxisome-organelle membrane contact sites and organelle cooperation. Furthermore, recent insights into peroxisome organisation through super-resolution microscopy are discussed. Finally, we address new roles for peroxisomes in immune and defence mechanisms and in human disorders, and for peroxisomal functions in different cell/tissue types, in particular their contribution to organ-specific pathologies.
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Grants
- BB/W015420/1, BB/V018167/1, BB/T002255/1, BB/R016844/1 Biotechnology and Biological Sciences Research Council
- BB/W015420/1, BB/V018167/1, BB/T002255/1, BB/R016844/1 Biotechnology and Biological Sciences Research Council
- BB/W015420/1, BB/V018167/1, BB/T002255/1, BB/R016844/1 Biotechnology and Biological Sciences Research Council
- European Union’s Horizon 2020 research and innovation programme
- Deutsches Zentrum für Herz-Kreislaufforschung
- German Research Foundation
- Medical Faculty Mannheim, University of Heidelberg
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Affiliation(s)
- Rechal Kumar
- Faculty of Health and Life Sciences, Department of Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK
| | - Markus Islinger
- Institute of Neuroanatomy, Medical Faculty Mannheim, Mannheim Centre for Translational Neuroscience, University of Heidelberg, 68167, Mannheim, Germany
| | - Harley Worthy
- Faculty of Health and Life Sciences, Department of Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK
| | - Ruth Carmichael
- Faculty of Health and Life Sciences, Department of Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK.
| | - Michael Schrader
- Faculty of Health and Life Sciences, Department of Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK.
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4
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Landowski M, Gogoi P, Ikeda S, Ikeda A. Roles of transmembrane protein 135 in mitochondrial and peroxisomal functions - implications for age-related retinal disease. FRONTIERS IN OPHTHALMOLOGY 2024; 4:1355379. [PMID: 38576540 PMCID: PMC10993500 DOI: 10.3389/fopht.2024.1355379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
Aging is the most significant risk factor for age-related diseases in general, which is true for age-related diseases in the eye including age-related macular degeneration (AMD). Therefore, in order to identify potential therapeutic targets for these diseases, it is crucial to understand the normal aging process and how its mis-regulation could cause age-related diseases at the molecular level. Recently, abnormal lipid metabolism has emerged as one major aspect of age-related symptoms in the retina. Animal models provide excellent means to identify and study factors that regulate lipid metabolism in relation to age-related symptoms. Central to this review is the role of transmembrane protein 135 (TMEM135) in the retina. TMEM135 was identified through the characterization of a mutant mouse strain exhibiting accelerated retinal aging and positional cloning of the responsible mutation within the gene, indicating the crucial role of TMEM135 in regulating the normal aging process in the retina. Over the past decade, the molecular functions of TMEM135 have been explored in various models and tissues, providing insights into the regulation of metabolism, particularly lipid metabolism, through its action in multiple organelles. Studies indicated that TMEM135 is a significant regulator of peroxisomes, mitochondria, and their interaction. Here, we provide an overview of the molecular functions of TMEM135 which is crucial for regulating mitochondria, peroxisomes, and lipids. The review also discusses the age-dependent phenotypes in mice with TMEM135 perturbations, emphasizing the importance of a balanced TMEM135 function for the health of the retina and other tissues including the heart, liver, and adipose tissue. Finally, we explore the potential roles of TMEM135 in human age-related retinal diseases, connecting its functions to the pathobiology of AMD.
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Affiliation(s)
- Michael Landowski
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, United States
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, United States
| | - Purnima Gogoi
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, United States
| | - Sakae Ikeda
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, United States
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, United States
| | - Akihiro Ikeda
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, United States
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, United States
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5
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Zhou X, Yang Y, Wang G, Wang S, Sun D, Ou X, Lian Y, Li L. Molecular pathway of mitochondrial preprotein import through the TOM-TIM23 supercomplex. Nat Struct Mol Biol 2023; 30:1996-2008. [PMID: 37696957 DOI: 10.1038/s41594-023-01103-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 08/18/2023] [Indexed: 09/13/2023]
Abstract
Over half of mitochondrial proteins are imported from the cytosol via the pre-sequence pathway, controlled by the TOM complex in the outer membrane and the TIM23 complex in the inner membrane. The mechanisms through which proteins are translocated via the TOM and TIM23 complexes remain unclear. Here we report the assembly of the active TOM-TIM23 supercomplex of Saccharomyces cerevisiae with translocating polypeptide substrates. Electron cryo-microscopy analyses reveal that the polypeptide substrates pass the TOM complex through the center of a Tom40 subunit, interacting with a glutamine-rich region. Structural and biochemical analyses show that the TIM23 complex contains a heterotrimer of the subunits Tim23, Tim17 and Mgr2. The polypeptide substrates are shielded from lipids by Mgr2 and Tim17, which creates a translocation pathway characterized by a negatively charged entrance and a central hydrophobic region. These findings reveal an unexpected pre-sequence pathway through the TOM-TIM23 supercomplex spanning the double membranes of mitochondria.
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Affiliation(s)
- Xueyin Zhou
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Yuqi Yang
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Guopeng Wang
- School of Life Sciences, Peking University, Beijing, China
| | - Shanshan Wang
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Dongjie Sun
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Xiaomin Ou
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Yuke Lian
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Long Li
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China.
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6
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Prokopchuk G, Butenko A, Dacks JB, Speijer D, Field MC, Lukeš J. Lessons from the deep: mechanisms behind diversification of eukaryotic protein complexes. Biol Rev Camb Philos Soc 2023; 98:1910-1927. [PMID: 37336550 PMCID: PMC10952624 DOI: 10.1111/brv.12988] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 05/30/2023] [Accepted: 06/05/2023] [Indexed: 06/21/2023]
Abstract
Genetic variation is the major mechanism behind adaptation and evolutionary change. As most proteins operate through interactions with other proteins, changes in protein complex composition and subunit sequence provide potentially new functions. Comparative genomics can reveal expansions, losses and sequence divergence within protein-coding genes, but in silico analysis cannot detect subunit substitutions or replacements of entire protein complexes. Insights into these fundamental evolutionary processes require broad and extensive comparative analyses, from both in silico and experimental evidence. Here, we combine data from both approaches and consider the gamut of possible protein complex compositional changes that arise during evolution, citing examples of complete conservation to partial and total replacement by functional analogues. We focus in part on complexes in trypanosomes as they represent one of the better studied non-animal/non-fungal lineages, but extend insights across the eukaryotes by extensive comparative genomic analysis. We argue that gene loss plays an important role in diversification of protein complexes and hence enhancement of eukaryotic diversity.
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Affiliation(s)
- Galina Prokopchuk
- Institute of Parasitology, Biology Centre, Czech Academy of SciencesBranišovská 1160/31České Budějovice37005Czech Republic
- Faculty of ScienceUniversity of South BohemiaBranišovská 1160/31České Budějovice37005Czech Republic
| | - Anzhelika Butenko
- Institute of Parasitology, Biology Centre, Czech Academy of SciencesBranišovská 1160/31České Budějovice37005Czech Republic
- Faculty of ScienceUniversity of South BohemiaBranišovská 1160/31České Budějovice37005Czech Republic
- Life Science Research Centre, Faculty of ScienceUniversity of OstravaChittussiho 983/10Ostrava71000Czech Republic
| | - Joel B. Dacks
- Institute of Parasitology, Biology Centre, Czech Academy of SciencesBranišovská 1160/31České Budějovice37005Czech Republic
- Division of Infectious Diseases, Department of MedicineUniversity of Alberta1‐124 Clinical Sciences Building, 11350‐83 AvenueEdmontonT6G 2R3AlbertaCanada
- Centre for Life's Origins and Evolution, Department of Genetics, Evolution and the EnvironmentUniversity College LondonDarwin Building, Gower StreetLondonWC1E 6BTUK
| | - Dave Speijer
- Medical Biochemistry, Amsterdam UMCUniversity of AmsterdamMeibergdreef 15Amsterdam1105 AZThe Netherlands
| | - Mark C. Field
- Institute of Parasitology, Biology Centre, Czech Academy of SciencesBranišovská 1160/31České Budějovice37005Czech Republic
- School of Life SciencesUniversity of DundeeDow StreetDundeeDD1 5EHScotlandUK
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of SciencesBranišovská 1160/31České Budějovice37005Czech Republic
- Faculty of ScienceUniversity of South BohemiaBranišovská 1160/31České Budějovice37005Czech Republic
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7
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Fielden LF, Busch JD, Merkt SG, Ganesan I, Steiert C, Hasselblatt HB, Busto JV, Wirth C, Zufall N, Jungbluth S, Noll K, Dung JM, Butenko L, von der Malsburg K, Koch HG, Hunte C, van der Laan M, Wiedemann N. Central role of Tim17 in mitochondrial presequence protein translocation. Nature 2023; 621:627-634. [PMID: 37527780 PMCID: PMC10511324 DOI: 10.1038/s41586-023-06477-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 07/25/2023] [Indexed: 08/03/2023]
Abstract
The presequence translocase of the mitochondrial inner membrane (TIM23) represents the major route for the import of nuclear-encoded proteins into mitochondria1,2. About 60% of more than 1,000 different mitochondrial proteins are synthesized with amino-terminal targeting signals, termed presequences, which form positively charged amphiphilic α-helices3,4. TIM23 sorts the presequence proteins into the inner membrane or matrix. Various views, including regulatory and coupling functions, have been reported on the essential TIM23 subunit Tim17 (refs. 5-7). Here we mapped the interaction of Tim17 with matrix-targeted and inner membrane-sorted preproteins during translocation in the native membrane environment. We show that Tim17 contains conserved negative charges close to the intermembrane space side of the bilayer, which are essential to initiate presequence protein translocation along a distinct transmembrane cavity of Tim17 for both classes of preproteins. The amphiphilic character of mitochondrial presequences directly matches this Tim17-dependent translocation mechanism. This mechanism permits direct lateral release of transmembrane segments of inner membrane-sorted precursors into the inner membrane.
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Affiliation(s)
- Laura F Fielden
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Jakob D Busch
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Sandra G Merkt
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Iniyan Ganesan
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Conny Steiert
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Hanna B Hasselblatt
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Jon V Busto
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Christophe Wirth
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Nicole Zufall
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Sibylle Jungbluth
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling, PZMS, Saarland University, Homburg, Germany
| | - Katja Noll
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling, PZMS, Saarland University, Homburg, Germany
| | - Julia M Dung
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ludmila Butenko
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Karina von der Malsburg
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling, PZMS, Saarland University, Homburg, Germany
| | - Hans-Georg Koch
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Carola Hunte
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- CIBSS-Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- BIOSS-Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Martin van der Laan
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling, PZMS, Saarland University, Homburg, Germany.
| | - Nils Wiedemann
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
- CIBSS-Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
- BIOSS-Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
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8
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Zhang Y, Hu Y, Wang Z, Lin X, Li Z, Ren Y, Zhao J. The translocase of the inner mitochondrial membrane 22-2 is required for mitochondrial membrane function during Arabidopsis seed development. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:4427-4448. [PMID: 37105529 DOI: 10.1093/jxb/erad141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 04/27/2023] [Indexed: 06/19/2023]
Abstract
The carrier translocase (also known as translocase of the inner membrane 22; TIM22 complex) is an important component of the mitochondrial protein import apparatus. However, the biological functions of AtTIM22-2 in Arabidopsis remain poorly defined. Here, we report studies on two tim22-2 mutants that exhibit defects in embryo and endosperm development, leading to seed abortion. AtTIM22-2, which was localized in mitochondria, was widely expressed in embryos and in various seedling organs. Loss of AtTIM22-2 function resulted in irregular mitochondrial cristae, decreased respiratory activity, and a lower membrane potential, together with changes in gene expression and enzyme activity related to reactive oxygen species (ROS) metabolism, leading to increased accumulation of ROS in the embryo. The levels of transcripts encoding mitochondrial protein import components were also altered in the tim22-2 mutants. Furthermore, mass spectrometry, bimolecular fluorescence complementation and co-immunoprecipitation assays revealed that AtTIM22-2 interacted with AtTIM23-2, AtB14.7 (a member of Arabidopsis OEP16 family encoded by At2G42210), and AT5G27395 (mitochondrial inner membrane translocase complex, subunit TIM44-related protein). Taken together, these results demonstrate that AtTIM22-2 is essential for maintaining mitochondrial membrane functions during seed development. These findings lay the foundations for a new model of the composition and functions of the TIM22 complex in higher plants.
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Affiliation(s)
- Yuqin Zhang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yuanyuan Hu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Zhiqin Wang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Xiaodi Lin
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Zihui Li
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yafang Ren
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Jie Zhao
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
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9
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Kocherlakota S, Swinkels D, Van Veldhoven PP, Baes M. Mouse Models to Study Peroxisomal Functions and Disorders: Overview, Caveats, and Recommendations. Methods Mol Biol 2023; 2643:469-500. [PMID: 36952207 DOI: 10.1007/978-1-0716-3048-8_34] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
During the last three decades many mouse lines were created or identified that are deficient in one or more peroxisomal functions. Different methodologies were applied to obtain global, hypomorph, cell type selective, inducible, and knockin mice. Whereas some models closely mimic pathologies in patients, others strongly deviate or no human counterpart has been reported. Often, mice, apparently endowed with a stronger transcriptional adaptation, have to be challenged with dietary additions or restrictions in order to trigger phenotypic changes. Depending on the inactivated peroxisomal protein, several approaches can be taken to validate the loss-of-function. Here, an overview is given of the available mouse models and their most important characteristics.
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Affiliation(s)
- Sai Kocherlakota
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Daniëlle Swinkels
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Paul P Van Veldhoven
- Laboratory of Peroxisome Biology and Intracellular Communication, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Myriam Baes
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium.
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10
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Reduced mitochondria provide an essential function for the cytosolic methionine cycle. Curr Biol 2022; 32:5057-5068.e5. [PMID: 36347252 PMCID: PMC9746703 DOI: 10.1016/j.cub.2022.10.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 08/15/2022] [Accepted: 10/14/2022] [Indexed: 11/09/2022]
Abstract
The loss of mitochondria in oxymonad protists has been associated with the redirection of the essential Fe-S cluster assembly to the cytosol. Yet as our knowledge of diverse free-living protists broadens, the list of functions of their mitochondrial-related organelles (MROs) expands. We revealed another such function in the closest oxymonad relative, Paratrimastix pyriformis, after we solved the proteome of its MRO with high accuracy, using localization of organelle proteins by isotope tagging (LOPIT). The newly assigned enzymes connect to the glycine cleavage system (GCS) and produce folate derivatives with one-carbon units and formate. These are likely to be used by the cytosolic methionine cycle involved in S-adenosyl methionine recycling. The data provide consistency with the presence of the GCS in MROs of free-living species and its absence in most endobionts, which typically lose the methionine cycle and, in the case of oxymonads, the mitochondria.
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11
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Wang G, Wang Y, Ni J, Li R, Zhu F, Wang R, Tian Q, Shen Q, Yang Q, Tang J, Murcha MW, Wang G. An MCIA-like complex is required for mitochondrial complex I assembly and seed development in maize. MOLECULAR PLANT 2022; 15:1470-1487. [PMID: 35957532 DOI: 10.1016/j.molp.2022.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 05/13/2022] [Accepted: 08/08/2022] [Indexed: 06/15/2023]
Abstract
During adaptive radiation, mitochondria have co-evolved with their hosts, leading to gain or loss of subunits and assembly factors of respiratory complexes. Plant mitochondrial complex I harbors ∼40 nuclear- and 9 mitochondrial-encoded subunits, and is formed by stepwise assembly during which different intermediates are integrated via various assembly factors. In mammals, the mitochondrial complex I intermediate assembly (MCIA) complex is required for building the membrane arm module. However, plants have lost almost all of the MCIA complex components, giving rise to the hypothesis that plants follow an ancestral pathway to assemble the membrane arm subunits. Here, we characterize a maize crumpled seed mutant, crk1, and reveal by map-based cloning that CRK1 encodes an ortholog of human complex I assembly factor 1, zNDUFAF1, the only evolutionarily conserved MCIA subunit in plants. zNDUFAF1 is localized in the mitochondria and accumulates in two intermediate complexes that contain complex I membrane arm subunits. Disruption of zNDUFAF1 results in severe defects in complex I assembly and activity, a cellular bioenergetic shift to aerobic glycolysis, and mitochondrial vacuolation. Moreover, we found that zNDUFAF1, the putative mitochondrial import inner membrane translocase ZmTIM17-1, and the isovaleryl-coenzyme A dehydrogenase ZmIVD1 interact each other, and could be co-precipitated from the mitochondria and co-migrate in the same assembly intermediates. Knockout of either ZmTIM17-1 or ZmIVD1 could lead to the significantly reduced complex I stability and activity as well as defective seeds. These results suggest that zNDUFAF1, ZmTIM17-1 and ZmIVD1 probably form an MCIA-like complex that is essential for the biogenesis of mitochondrial complex I and seed development in maize. Our findings also imply that plants and mammals recruit MCIA subunits independently for mitochondrial complex I assembly, highlighting the importance of parallel evolution in mitochondria adaptation to their hosts.
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Affiliation(s)
- Gang Wang
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yongyan Wang
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT--China Joint Center of Wheat and Maize, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China
| | - Jiacheng Ni
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Rongrong Li
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT--China Joint Center of Wheat and Maize, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China
| | - Fengling Zhu
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT--China Joint Center of Wheat and Maize, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China
| | - Ruyin Wang
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT--China Joint Center of Wheat and Maize, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China
| | - Qiuzhen Tian
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT--China Joint Center of Wheat and Maize, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China
| | - Qingwen Shen
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT--China Joint Center of Wheat and Maize, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China
| | - Qinghua Yang
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT--China Joint Center of Wheat and Maize, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China
| | - Jihua Tang
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT--China Joint Center of Wheat and Maize, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China; The Shennong Laboratory, Zhengzhou, Henan 450002, China
| | - Monika W Murcha
- School of Molecular Sciences & The ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, WA 6009, Australia
| | - Guifeng Wang
- National Key Laboratory of Wheat and Maize Crops Science, CIMMYT--China Joint Center of Wheat and Maize, Center for Crop Genome Engineering, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China.
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12
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Tachezy J, Makki A, Hrdý I. The hydrogenosomes of Trichomonas vaginalis. J Eukaryot Microbiol 2022; 69:e12922. [PMID: 35567536 DOI: 10.1111/jeu.12922] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This review is dedicated to the 50th anniversary of the discovery of hydrogenosomes by Miklós Müller and Donald Lindmark, which we will celebrate the following year. It was a long journey from the first observation of enigmatic rows of granules in trichomonads at the end of the 19th century to their first biochemical characterization in 1973. The key experiments by Müller and Lindmark revealed that the isolated granules contain hydrogen-producing hydrogenase, similar to some anaerobic bacteria-a discovery that gave birth to the field of hydrogenosomes. It is also important to acknowledge the parallel work of the team of Apolena Čerkasovová, Jiří Čerkasov, and Jaroslav Kulda, who demonstrated that these granules, similar to mitochondria, produce ATP. However, the evolutionary origin of hydrogenosomes remained enigmatic until the turn of the millennium, when it was finally accepted that hydrogenosomes and mitochondria evolved from a common ancestor. After a historical introduction, the review provides an overview of hydrogenosome biogenesis, hydrogenosomal protein import, and the relationship between the peculiar structure of membrane translocases and its low inner membrane potential due to the lack of respiratory complexes. Next, it summarizes the current state of knowledge on energy metabolism, the oxygen defense system, and iron/sulfur cluster assembly.
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Affiliation(s)
- Jan Tachezy
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, 25242 Vestec, Czech Republic
| | - Abhijith Makki
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, 25242 Vestec, Czech Republic
| | - Ivan Hrdý
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, 25242 Vestec, Czech Republic
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13
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Schneider A. Evolution and diversification of mitochondrial protein import systems. Curr Opin Cell Biol 2022; 75:102077. [PMID: 35390639 DOI: 10.1016/j.ceb.2022.102077] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 02/22/2022] [Accepted: 02/24/2022] [Indexed: 11/03/2022]
Abstract
More than 95% of mitochondrial proteins are encoded in the nucleus, synthesised in the cytosol and imported into the organelle. The evolution of mitochondrial protein import systems was therefore a prerequisite for the conversion of the α-proteobacterial mitochondrial ancestor into an organelle. Here, I review that the origin of the mitochondrial outer membrane import receptors can best be understood by convergent evolution. Subsequently, I discuss an evolutionary scenario that was proposed to explain the diversification of the inner membrane carrier protein translocases between yeast and mammals. Finally, I illustrate a scenario that can explain how the two specialised inner membrane protein translocase complexes found in most eukaryotes were reduced to a single multifunctional one in trypanosomes.
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Affiliation(s)
- André Schneider
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, Freiestrasse 3, 3012 Bern, Switzerland.
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14
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Kumar A, Matta SK, Vigneshwaran R, D'Silva P. A journey through the gateway of polytopic inner membrane proteins: The carrier translocase machinery. CURRENT OPINION IN PHYSIOLOGY 2022. [DOI: 10.1016/j.cophys.2022.100533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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15
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Jackson TD, Crameri JJ, Muellner-Wong L, Frazier AE, Palmer CS, Formosa LE, Hock DH, Fujihara KM, Stait T, Sharpe AJ, Thorburn DR, Ryan MT, Stroud DA, Stojanovski D. Sideroflexin 4 is a complex I assembly factor that interacts with the MCIA complex and is required for the assembly of the ND2 module. Proc Natl Acad Sci U S A 2022; 119:e2115566119. [PMID: 35333655 PMCID: PMC9060475 DOI: 10.1073/pnas.2115566119] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 02/11/2022] [Indexed: 12/23/2022] Open
Abstract
SignificanceMitochondria are double-membraned eukaryotic organelles that house the proteins required for generation of ATP, the energy currency of cells. ATP generation within mitochondria is performed by five multisubunit complexes (complexes I to V), the assembly of which is an intricate process. Mutations in subunits of these complexes, or the suite of proteins that help them assemble, lead to a severe multisystem condition called mitochondrial disease. We show that SFXN4, a protein that causes mitochondrial disease when mutated, assists with the assembly of complex I. This finding explains why mutations in SFXN4 cause mitochondrial disease and is surprising because SFXN4 belongs to a family of amino acid transporter proteins, suggesting that it has undergone a dramatic shift in function through evolution.
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Affiliation(s)
- Thomas D. Jackson
- Department of Biochemistry and Pharmacology, The University of Melbourne, Parkville, VIC 3010, Australia
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Jordan J. Crameri
- Department of Biochemistry and Pharmacology, The University of Melbourne, Parkville, VIC 3010, Australia
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Linden Muellner-Wong
- Department of Biochemistry and Pharmacology, The University of Melbourne, Parkville, VIC 3010, Australia
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia
- Murdoch Children’s Research Institute, Royal Children’s Hospital, Melbourne, VIC 3052, Australia
| | - Ann E. Frazier
- Murdoch Children’s Research Institute, Royal Children’s Hospital, Melbourne, VIC 3052, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia
| | - Catherine S. Palmer
- Department of Biochemistry and Pharmacology, The University of Melbourne, Parkville, VIC 3010, Australia
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Luke E. Formosa
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC 3168, Australia
| | - Daniella H. Hock
- Department of Biochemistry and Pharmacology, The University of Melbourne, Parkville, VIC 3010, Australia
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Kenji M. Fujihara
- Division of Cancer Research, Peter MacCallum Cancer Centre, Melbourne, VIC 3000, Australia
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Tegan Stait
- Murdoch Children’s Research Institute, Royal Children’s Hospital, Melbourne, VIC 3052, Australia
- Victorian Clinical Genetic Services, Royal Children’s Hospital, Melbourne, VIC 3052, Australia
| | - Alice J. Sharpe
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC 3168, Australia
| | - David R. Thorburn
- Murdoch Children’s Research Institute, Royal Children’s Hospital, Melbourne, VIC 3052, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, VIC 3052, Australia
- Victorian Clinical Genetic Services, Royal Children’s Hospital, Melbourne, VIC 3052, Australia
| | - Michael T. Ryan
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC 3168, Australia
| | - David A. Stroud
- Department of Biochemistry and Pharmacology, The University of Melbourne, Parkville, VIC 3010, Australia
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia
- Murdoch Children’s Research Institute, Royal Children’s Hospital, Melbourne, VIC 3052, Australia
| | - Diana Stojanovski
- Department of Biochemistry and Pharmacology, The University of Melbourne, Parkville, VIC 3010, Australia
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia
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16
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Güngör B, Flohr T, Garg SG, Herrmann JM. The ER membrane complex (EMC) can functionally replace the Oxa1 insertase in mitochondria. PLoS Biol 2022; 20:e3001380. [PMID: 35231030 PMCID: PMC8887752 DOI: 10.1371/journal.pbio.3001380] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 12/17/2021] [Indexed: 12/18/2022] Open
Abstract
Two multisubunit protein complexes for membrane protein insertion were recently identified in the endoplasmic reticulum (ER): the guided entry of tail anchor proteins (GET) complex and ER membrane complex (EMC). The structures of both of their hydrophobic core subunits, which are required for the insertion reaction, revealed an overall similarity to the YidC/Oxa1/Alb3 family members found in bacteria, mitochondria, and chloroplasts. This suggests that these membrane insertion machineries all share a common ancestry. To test whether these ER proteins can functionally replace Oxa1 in yeast mitochondria, we generated strains that express mitochondria-targeted Get2-Get1 and Emc6-Emc3 fusion proteins in Oxa1 deletion mutants. Interestingly, the Emc6-Emc3 fusion was able to complement an Δoxa1 mutant and restored its respiratory competence. The Emc6-Emc3 fusion promoted the insertion of the mitochondrially encoded protein Cox2, as well as of nuclear encoded inner membrane proteins, although was not able to facilitate the assembly of the Atp9 ring. Our observations indicate that protein insertion into the ER is functionally conserved to the insertion mechanism in bacteria and mitochondria and adheres to similar topological principles.
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Affiliation(s)
- Büsra Güngör
- Cell Biology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Tamara Flohr
- Cell Biology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Sriram G. Garg
- Institute for Molecular Evolution, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
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17
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Mice with a deficiency in Peroxisomal Membrane Protein 4 (PXMP4) display mild changes in hepatic lipid metabolism. Sci Rep 2022; 12:2512. [PMID: 35169201 PMCID: PMC8847483 DOI: 10.1038/s41598-022-06479-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 01/31/2022] [Indexed: 11/08/2022] Open
Abstract
Peroxisomes play an important role in the metabolism of a variety of biomolecules, including lipids and bile acids. Peroxisomal Membrane Protein 4 (PXMP4) is a ubiquitously expressed peroxisomal membrane protein that is transcriptionally regulated by peroxisome proliferator-activated receptor α (PPARα), but its function is still unknown. To investigate the physiological function of PXMP4, we generated a Pxmp4 knockout (Pxmp4-/-) mouse model using CRISPR/Cas9-mediated gene editing. Peroxisome function was studied under standard chow-fed conditions and after stimulation of peroxisomal activity using the PPARα ligand fenofibrate or by using phytol, a metabolite of chlorophyll that undergoes peroxisomal oxidation. Pxmp4-/- mice were viable, fertile, and displayed no changes in peroxisome numbers or morphology under standard conditions. Also, no differences were observed in the plasma levels of products from major peroxisomal pathways, including very long-chain fatty acids (VLCFAs), bile acids (BAs), and BA intermediates di- and trihydroxycholestanoic acid. Although elevated levels of the phytol metabolites phytanic and pristanic acid in Pxmp4-/- mice pointed towards an impairment in peroxisomal α-oxidation capacity, treatment of Pxmp4-/- mice with a phytol-enriched diet did not further increase phytanic/pristanic acid levels. Finally, lipidomic analysis revealed that loss of Pxmp4 decreased hepatic levels of the alkyldiacylglycerol class of neutral ether lipids, particularly those containing polyunsaturated fatty acids. Together, our data show that while PXMP4 is not critical for overall peroxisome function under the conditions tested, it may have a role in the metabolism of (ether)lipids.
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18
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Landowski M, Bhute VJ, Takimoto T, Grindel S, Shahi PK, Pattnaik BR, Ikeda S, Ikeda A. A mutation in transmembrane protein 135 impairs lipid metabolism in mouse eyecups. Sci Rep 2022; 12:756. [PMID: 35031662 PMCID: PMC8760256 DOI: 10.1038/s41598-021-04644-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 12/28/2021] [Indexed: 12/13/2022] Open
Abstract
Aging is a significant factor in the development of age-related diseases but how aging disrupts cellular homeostasis to cause age-related retinal disease is unknown. Here, we further our studies on transmembrane protein 135 (Tmem135), a gene involved in retinal aging, by examining the transcriptomic profiles of wild-type, heterozygous and homozygous Tmem135 mutant posterior eyecup samples through RNA sequencing (RNA-Seq). We found significant gene expression changes in both heterozygous and homozygous Tmem135 mutant mouse eyecups that correlate with visual function deficits. Further analysis revealed that expression of many genes involved in lipid metabolism are changed due to the Tmem135 mutation. Consistent with these changes, we found increased lipid accumulation in mutant Tmem135 eyecup samples. Since mutant Tmem135 mice have similar ocular pathologies as human age-related macular degeneration (AMD) eyes, we compared our homozygous Tmem135 mutant eyecup RNA-Seq dataset with transcriptomic datasets of human AMD donor eyes. We found similar changes in genes involved in lipid metabolism between the homozygous Tmem135 mutant eyecups and AMD donor eyes. Our study suggests that the Tmem135 mutation affects lipid metabolism as similarly observed in human AMD eyes, thus Tmem135 mutant mice can serve as a good model for the role of dysregulated lipid metabolism in AMD.
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Affiliation(s)
- Michael Landowski
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, USA
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, USA
| | - Vijesh J Bhute
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, USA
- Department of Chemical Engineering, Imperial College London, South Kensington, London, SW7 2AZ, UK
| | - Tetsuya Takimoto
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, USA
| | - Samuel Grindel
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, USA
| | - Pawan K Shahi
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, USA
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, USA
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Bikash R Pattnaik
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, USA
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, USA
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Sakae Ikeda
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, USA
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, USA
| | - Akihiro Ikeda
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, USA.
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, USA.
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19
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Petrů M, Dohnálek V, Füssy Z, Doležal P. Fates of Sec, Tat, and YidC Translocases in Mitochondria and Other Eukaryotic Compartments. Mol Biol Evol 2021; 38:5241-5254. [PMID: 34436602 PMCID: PMC8662606 DOI: 10.1093/molbev/msab253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Formation of mitochondria by the conversion of a bacterial endosymbiont was a key moment in the evolution of eukaryotes. It was made possible by outsourcing the endosymbiont's genetic control to the host nucleus, while developing the import machinery for proteins synthesized on cytosolic ribosomes. The original protein export machines of the nascent organelle remained to be repurposed or were completely abandoned. This review follows the evolutionary fates of three prokaryotic inner membrane translocases Sec, Tat, and YidC. Homologs of all three translocases can still be found in current mitochondria, but with different importance for mitochondrial function. Although the mitochondrial YidC homolog, Oxa1, became an omnipresent independent insertase, the other two remained only sporadically present in mitochondria. Only a single substrate is known for the mitochondrial Tat and no function has yet been assigned for the mitochondrial Sec. Finally, this review compares these ancestral mitochondrial proteins with their paralogs operating in the plastids and the endomembrane system.
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Affiliation(s)
- Markéta Petrů
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Vít Dohnálek
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Zoltán Füssy
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Pavel Doležal
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
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20
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Dimogkioka AR, Lees J, Lacko E, Tokatlidis K. Protein import in mitochondria biogenesis: guided by targeting signals and sustained by dedicated chaperones. RSC Adv 2021; 11:32476-32493. [PMID: 35495482 PMCID: PMC9041937 DOI: 10.1039/d1ra04497d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 09/25/2021] [Indexed: 12/31/2022] Open
Abstract
Mitochondria have a central role in cellular metabolism; they are responsible for the biosynthesis of amino acids, lipids, iron-sulphur clusters and regulate apoptosis. About 99% of mitochondrial proteins are encoded by nuclear genes, so the biogenesis of mitochondria heavily depends on protein import pathways into the organelle. An intricate system of well-studied import machinery facilitates the import of mitochondrial proteins. In addition, folding of the newly synthesized proteins takes place in a busy environment. A system of folding helper proteins, molecular chaperones and co-chaperones, are present to maintain proper conformation and thus avoid protein aggregation and premature damage. The components of the import machinery are well characterised, but the targeting signals and how they are recognised and decoded remains in some cases unclear. Here we provide some detail on the types of targeting signals involved in the protein import process. Furthermore, we discuss the very elaborate chaperone systems of the intermembrane space that are needed to overcome the particular challenges for the folding process in this compartment. The mechanisms that sustain productive folding in the face of aggregation and damage in mitochondria are critical components of the stress response and play an important role in cell homeostasis.
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Affiliation(s)
- Anna-Roza Dimogkioka
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow University Avenue Glasgow G12 8QQ Scotland UK
| | - Jamie Lees
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow University Avenue Glasgow G12 8QQ Scotland UK
| | - Erik Lacko
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow University Avenue Glasgow G12 8QQ Scotland UK
| | - Kostas Tokatlidis
- Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow University Avenue Glasgow G12 8QQ Scotland UK
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21
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Knapp-Wilson A, Pereira GC, Buzzard E, Ford HC, Richardson A, Corey RA, Neal C, Verkade P, Halestrap AP, Gold VAM, Kuwabara PE, Collinson I. Maintenance of complex I and its supercomplexes by NDUF-11 is essential for mitochondrial structure, function and health. J Cell Sci 2021; 134:jcs258399. [PMID: 34106255 PMCID: PMC8277142 DOI: 10.1242/jcs.258399] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 05/28/2021] [Indexed: 12/22/2022] Open
Abstract
Mitochondrial supercomplexes form around a conserved core of monomeric complex I and dimeric complex III; wherein a subunit of the former, NDUFA11, is conspicuously situated at the interface. We identified nduf-11 (B0491.5) as encoding the Caenorhabditis elegans homologue of NDUFA11. Animals homozygous for a CRISPR-Cas9-generated knockout allele of nduf-11 arrested at the second larval (L2) development stage. Reducing (but not eliminating) expression using RNAi allowed development to adulthood, enabling characterisation of the consequences: destabilisation of complex I and its supercomplexes and perturbation of respiratory function. The loss of NADH dehydrogenase activity was compensated by enhanced complex II activity, with the potential for detrimental reactive oxygen species (ROS) production. Cryo-electron tomography highlighted aberrant morphology of cristae and widening of both cristae junctions and the intermembrane space. The requirement of NDUF-11 for balanced respiration, mitochondrial morphology and development presumably arises due to its involvement in complex I and supercomplex maintenance. This highlights the importance of respiratory complex integrity for health and the potential for its perturbation to cause mitochondrial disease. This article has an associated First Person interview with Amber Knapp-Wilson, joint first author of the paper.
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Affiliation(s)
| | | | - Emma Buzzard
- Living Systems Institute, Stocker Road, University of Exeter, Exeter EX4 4QD, UK
- College of Life and Environmental Sciences,Geoffrey Pope Building, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - Holly C. Ford
- School of Biochemistry, University of Bristol, Bristol BS8 1TD, UK
| | | | - Robin A. Corey
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Chris Neal
- Wolfson Bioimaging Facility, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Paul Verkade
- School of Biochemistry, University of Bristol, Bristol BS8 1TD, UK
| | | | - Vicki A. M. Gold
- Living Systems Institute, Stocker Road, University of Exeter, Exeter EX4 4QD, UK
- College of Life and Environmental Sciences,Geoffrey Pope Building, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | | | - Ian Collinson
- School of Biochemistry, University of Bristol, Bristol BS8 1TD, UK
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22
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Needs HI, Protasoni M, Henley JM, Prudent J, Collinson I, Pereira GC. Interplay between Mitochondrial Protein Import and Respiratory Complexes Assembly in Neuronal Health and Degeneration. Life (Basel) 2021; 11:432. [PMID: 34064758 PMCID: PMC8151517 DOI: 10.3390/life11050432] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/27/2021] [Accepted: 05/02/2021] [Indexed: 12/14/2022] Open
Abstract
The fact that >99% of mitochondrial proteins are encoded by the nuclear genome and synthesised in the cytosol renders the process of mitochondrial protein import fundamental for normal organelle physiology. In addition to this, the nuclear genome comprises most of the proteins required for respiratory complex assembly and function. This means that without fully functional protein import, mitochondrial respiration will be defective, and the major cellular ATP source depleted. When mitochondrial protein import is impaired, a number of stress response pathways are activated in order to overcome the dysfunction and restore mitochondrial and cellular proteostasis. However, prolonged impaired mitochondrial protein import and subsequent defective respiratory chain function contributes to a number of diseases including primary mitochondrial diseases and neurodegeneration. This review focuses on how the processes of mitochondrial protein translocation and respiratory complex assembly and function are interlinked, how they are regulated, and their importance in health and disease.
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Affiliation(s)
- Hope I. Needs
- School of Biochemistry, University of Bristol, Bristol BS8 1TD, UK; (H.I.N.); (J.M.H.)
| | - Margherita Protasoni
- Medical Research Council-Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK; (M.P.); (J.P.)
| | - Jeremy M. Henley
- School of Biochemistry, University of Bristol, Bristol BS8 1TD, UK; (H.I.N.); (J.M.H.)
- Centre for Neuroscience and Regenerative Medicine, Faculty of Science, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Julien Prudent
- Medical Research Council-Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK; (M.P.); (J.P.)
| | - Ian Collinson
- School of Biochemistry, University of Bristol, Bristol BS8 1TD, UK; (H.I.N.); (J.M.H.)
| | - Gonçalo C. Pereira
- Medical Research Council-Mitochondrial Biology Unit, University of Cambridge, Cambridge CB2 0XY, UK; (M.P.); (J.P.)
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23
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Caspari OD, Lafontaine I. The role of antimicrobial peptides in the evolution of endosymbiotic protein import. PLoS Pathog 2021; 17:e1009466. [PMID: 33857255 PMCID: PMC8049325 DOI: 10.1371/journal.ppat.1009466] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- Oliver D. Caspari
- UMR7141, Institut de Biologie Physico-Chimique (CNRS/Sorbonne Université), Paris, France
- * E-mail: (ODC); (IL)
| | - Ingrid Lafontaine
- UMR7141, Institut de Biologie Physico-Chimique (CNRS/Sorbonne Université), Paris, France
- * E-mail: (ODC); (IL)
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24
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Zhang Y, Ou X, Wang X, Sun D, Zhou X, Wu X, Li Q, Li L. Structure of the mitochondrial TIM22 complex from yeast. Cell Res 2021; 31:366-368. [PMID: 32918038 PMCID: PMC8027178 DOI: 10.1038/s41422-020-00399-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 07/24/2020] [Indexed: 01/30/2023] Open
Affiliation(s)
- Yutong Zhang
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking University, Beijing, China ,grid.11135.370000 0001 2256 9319Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China ,grid.11135.370000 0001 2256 9319Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Xiaomin Ou
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking University, Beijing, China ,grid.11135.370000 0001 2256 9319Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Xuezheng Wang
- grid.11135.370000 0001 2256 9319Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China ,grid.11135.370000 0001 2256 9319Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China ,grid.11135.370000 0001 2256 9319State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing, China
| | - Dongjie Sun
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking University, Beijing, China ,grid.11135.370000 0001 2256 9319Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Xueyin Zhou
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking University, Beijing, China ,grid.11135.370000 0001 2256 9319Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China ,grid.11135.370000 0001 2256 9319Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Xiaofei Wu
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking University, Beijing, China ,grid.11135.370000 0001 2256 9319Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Qing Li
- grid.11135.370000 0001 2256 9319Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China ,grid.11135.370000 0001 2256 9319State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing, China
| | - Long Li
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking University, Beijing, China ,grid.11135.370000 0001 2256 9319Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
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25
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Wang H, Liu H, Dai W, Luo S, Amos CI, Lee JE, Li X, Yue Y, Nan H, Wei Q. Association of genetic variants of TMEM135 and PEX5 in the peroxisome pathway with cutaneous melanoma-specific survival. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:396. [PMID: 33842617 PMCID: PMC8033299 DOI: 10.21037/atm-20-2117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Background Peroxisomes are ubiquitous and dynamic organelles that are involved in the metabolism of reactive oxygen species (ROS) and lipids. However, whether genetic variants in the peroxisome pathway genes are associated with survival in patients with melanoma has not been established. Therefore, our aim was to identify additional genetic variants in the peroxisome pathway that may provide new prognostic biomarkers for cutaneous melanoma (CM). Methods We assessed the associations between 8,397 common single-nucleotide polymorphisms (SNPs) in 88 peroxisome pathway genes and CM disease-specific survival (CMSS) in a two-stage analysis. For the discovery, we extracted the data from a published genome-wide association study from The University of Texas MD Anderson Cancer Center (MDACC). We then replicated the results in another dataset from the Nurse Health Study (NHS)/Health Professionals Follow-up Study (HPFS). Results Overall, 95 (11.1%) patients in the MDACC dataset and 48 (11.7%) patients in the NHS/HPFS dataset died of CM. We found 27 significant SNPs in the peroxisome pathway genes to be associated with CMSS in both datasets after multiple comparison correction using the Bayesian false-discovery probability method. In stepwise Cox proportional hazards regression analysis, with adjustment for other covariates and previously published SNPs in the MDACC dataset, we identified 2 independent SNPs (TMEM135 rs567403 C>G and PEX5 rs7969508 A>G) that predicted CMSS (P=0.003 and 0.031, respectively, in an additive genetic model). The expression quantitative trait loci analysis further revealed that the TMEM135 rs567403 GG and PEX5 rs7969508 GG genotypes were associated with increased and decreased levels of mRNA expression of their genes, respectively. Conclusions Once our findings are replicated by other investigators, these genetic variants may serve as novel biomarkers for the prediction of survival in patients with CM.
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Affiliation(s)
- Haijiao Wang
- Department of Gynecology Oncology, The First Hospital of Jilin University, Changchun, Jilin, China.,Duke Cancer Institute, Duke University Medical Center, Durham, NC, USA.,Department of Population Health Sciences, Duke University School of Medicine, Durham, NC, USA
| | - Hongliang Liu
- Duke Cancer Institute, Duke University Medical Center, Durham, NC, USA.,Department of Population Health Sciences, Duke University School of Medicine, Durham, NC, USA
| | - Wei Dai
- Department of Dermatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Sheng Luo
- Department of Biostatistics and Bioinformatics, Duke University School of Medicine, Durham, NC, USA
| | - Christopher I Amos
- Institute for Clinical and Translational Research, Baylor College of Medicine, Houston, TX, USA
| | - Jeffrey E Lee
- Department of Surgical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, TX, USA
| | - Xin Li
- Department of Epidemiology, Richard M. Fairbanks School of Public Health, Indiana University, Indianapolis, IN, USA
| | - Ying Yue
- Department of Gynecology Oncology, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Hongmei Nan
- Department of Epidemiology, Richard M. Fairbanks School of Public Health, Indiana University, Indianapolis, IN, USA
| | - Qingyi Wei
- Duke Cancer Institute, Duke University Medical Center, Durham, NC, USA.,Department of Population Health Sciences, Duke University School of Medicine, Durham, NC, USA.,Department of Medicine, Duke University School of Medicine, Durham, NC, USA
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26
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Jackson TD, Hock DH, Fujihara KM, Palmer CS, Frazier AE, Low YC, Kang Y, Ang CS, Clemons NJ, Thorburn DR, Stroud DA, Stojanovski D. The TIM22 complex mediates the import of sideroflexins and is required for efficient mitochondrial one-carbon metabolism. Mol Biol Cell 2021; 32:475-491. [PMID: 33476211 PMCID: PMC8101445 DOI: 10.1091/mbc.e20-06-0390] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Acylglycerol kinase (AGK) is a mitochondrial lipid kinase that contributes to protein biogenesis as a subunit of the TIM22 complex at the inner mitochondrial membrane. Mutations in AGK cause Sengers syndrome, an autosomal recessive condition characterized by congenital cataracts, hypertrophic cardiomyopathy, skeletal myopathy, and lactic acidosis. We mapped the proteomic changes in Sengers patient fibroblasts and AGKKO cell lines to understand the effects of AGK dysfunction on mitochondria. This uncovered down-regulation of a number of proteins at the inner mitochondrial membrane, including many SLC25 carrier family proteins, which are predicted substrates of the complex. We also observed down-regulation of SFXN proteins, which contain five transmembrane domains, and show that they represent a novel class of TIM22 complex substrate. Perturbed biogenesis of SFXN proteins in cells lacking AGK reduces the proliferative capabilities of these cells in the absence of exogenous serine, suggesting that dysregulation of one-carbon metabolism is a molecular feature in the biology of Sengers syndrome.
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Affiliation(s)
- Thomas D Jackson
- Department of Biochemistry and Pharmacology and The Bio21 Molecular Science and Biotechnology Institute
| | - Daniella H Hock
- Department of Biochemistry and Pharmacology and The Bio21 Molecular Science and Biotechnology Institute
| | - Kenji M Fujihara
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Victoria 3010, Australia.,Division of Cancer Research, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia
| | - Catherine S Palmer
- Department of Biochemistry and Pharmacology and The Bio21 Molecular Science and Biotechnology Institute
| | - Ann E Frazier
- Murdoch Children's Research Institute and.,Department of Paediatrics, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Yau C Low
- Murdoch Children's Research Institute and.,Department of Paediatrics, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Yilin Kang
- Department of Biochemistry and Pharmacology and The Bio21 Molecular Science and Biotechnology Institute
| | - Ching-Seng Ang
- Bio21 Mass Spectrometry and Proteomics Facility, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Nicholas J Clemons
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Victoria 3010, Australia.,Division of Cancer Research, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia
| | - David R Thorburn
- Murdoch Children's Research Institute and.,Victorian Clinical Genetics Services Royal Children's Hospital, Melbourne, Victoria 3052, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - David A Stroud
- Department of Biochemistry and Pharmacology and The Bio21 Molecular Science and Biotechnology Institute
| | - Diana Stojanovski
- Department of Biochemistry and Pharmacology and The Bio21 Molecular Science and Biotechnology Institute
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27
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Chornyi S, IJlst L, van Roermund CWT, Wanders RJA, Waterham HR. Peroxisomal Metabolite and Cofactor Transport in Humans. Front Cell Dev Biol 2021; 8:613892. [PMID: 33505966 PMCID: PMC7829553 DOI: 10.3389/fcell.2020.613892] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Accepted: 12/10/2020] [Indexed: 12/20/2022] Open
Abstract
Peroxisomes are membrane-bound organelles involved in many metabolic pathways and essential for human health. They harbor a large number of enzymes involved in the different pathways, thus requiring transport of substrates, products and cofactors involved across the peroxisomal membrane. Although much progress has been made in understanding the permeability properties of peroxisomes, there are still important gaps in our knowledge about the peroxisomal transport of metabolites and cofactors. In this review, we discuss the different modes of transport of metabolites and essential cofactors, including CoA, NAD+, NADP+, FAD, FMN, ATP, heme, pyridoxal phosphate, and thiamine pyrophosphate across the peroxisomal membrane. This transport can be mediated by non-selective pore-forming proteins, selective transport proteins, membrane contact sites between organelles, and co-import of cofactors with proteins. We also discuss modes of transport mediated by shuttle systems described for NAD+/NADH and NADP+/NADPH. We mainly focus on current knowledge on human peroxisomal metabolite and cofactor transport, but also include knowledge from studies in plants, yeast, fruit fly, zebrafish, and mice, which has been exemplary in understanding peroxisomal transport mechanisms in general.
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Affiliation(s)
- Serhii Chornyi
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC Location AMC, University of Amsterdam, Amsterdam, Netherlands
| | - Lodewijk IJlst
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC Location AMC, University of Amsterdam, Amsterdam, Netherlands
| | - Carlo W T van Roermund
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC Location AMC, University of Amsterdam, Amsterdam, Netherlands
| | - Ronald J A Wanders
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC Location AMC, University of Amsterdam, Amsterdam, Netherlands
| | - Hans R Waterham
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC Location AMC, University of Amsterdam, Amsterdam, Netherlands
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28
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Shikha S, Huot JL, Schneider A, Niemann M. tRNA import across the mitochondrial inner membrane in T. brucei requires TIM subunits but is independent of protein import. Nucleic Acids Res 2020; 48:12269-12281. [PMID: 33231678 PMCID: PMC7708065 DOI: 10.1093/nar/gkaa1098] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 10/20/2020] [Accepted: 11/03/2020] [Indexed: 01/27/2023] Open
Abstract
Mitochondrial tRNA import is widespread, but mechanistic insights of how tRNAs are translocated across mitochondrial membranes remain scarce. The parasitic protozoan T. brucei lacks mitochondrial tRNA genes. Consequently, it imports all organellar tRNAs from the cytosol. Here we investigated the connection between tRNA and protein translocation across the mitochondrial inner membrane. Trypanosomes have a single inner membrane protein translocase that consists of three heterooligomeric submodules, which all are required for import of matrix proteins. In vivo depletion of individual submodules shows that surprisingly only the integral membrane core module, including the protein import pore, but not the presequence-associated import motor are required for mitochondrial tRNA import. Thus we could uncouple import of matrix proteins from import of tRNAs even though both substrates are imported into the same mitochondrial subcompartment. This is reminiscent to the outer membrane where the main protein translocase but not on-going protein translocation is required for tRNA import. We also show that import of tRNAs across the outer and inner membranes are coupled to each other. Taken together, these data support the 'alternate import model', which states that tRNA and protein import while mechanistically independent use the same translocation pores but not at the same time.
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Affiliation(s)
- Shikha Shikha
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Jonathan L Huot
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - André Schneider
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Moritz Niemann
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
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29
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Chaudhuri M, Darden C, Soto Gonzalez F, Singha UK, Quinones L, Tripathi A. Tim17 Updates: A Comprehensive Review of an Ancient Mitochondrial Protein Translocator. Biomolecules 2020; 10:E1643. [PMID: 33297490 PMCID: PMC7762337 DOI: 10.3390/biom10121643] [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: 10/16/2020] [Revised: 12/02/2020] [Accepted: 12/03/2020] [Indexed: 02/06/2023] Open
Abstract
The translocases of the mitochondrial outer and inner membranes, the TOM and TIMs, import hundreds of nucleus-encoded proteins into mitochondria. TOM and TIMs are multi-subunit protein complexes that work in cooperation with other complexes to import proteins in different sub-mitochondrial destinations. The overall architecture of these protein complexes is conserved among yeast/fungi, animals, and plants. Recent studies have revealed unique characteristics of this machinery, particularly in the eukaryotic supergroup Excavata. Despite multiple differences, homologues of Tim17, an essential component of one of the TIM complexes and a member of the Tim17/Tim22/Tim23 family, have been found in all eukaryotes. Here, we review the structure and function of Tim17 and Tim17-containing protein complexes in different eukaryotes, and then compare them to the single homologue of this protein found in Trypanosoma brucei, a unicellular parasitic protozoan.
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Affiliation(s)
- Minu Chaudhuri
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, 1005 Dr. D.B. Todd, Jr., Blvd, Nashville, TN 37208, USA; (C.D.); (F.S.G.); (U.K.S.); (L.Q.); (A.T.)
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30
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Landowski M, Grindel S, Shahi PK, Johnson A, Western D, Race A, Shi F, Benson J, Gao M, Santoirre E, Lee WH, Ikeda S, Pattnaik BR, Ikeda A. Modulation of Tmem135 Leads to Retinal Pigmented Epithelium Pathologies in Mice. Invest Ophthalmol Vis Sci 2020; 61:16. [PMID: 33064130 PMCID: PMC7581492 DOI: 10.1167/iovs.61.12.16] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 09/23/2020] [Indexed: 12/12/2022] Open
Abstract
Purpose Aging is a critical risk factor for the development of retinal diseases, but how aging perturbs ocular homeostasis and contributes to disease is unknown. We identified transmembrane protein 135 (Tmem135) as a gene important for regulating retinal aging and mitochondrial dynamics in mice. Overexpression of Tmem135 causes mitochondrial fragmentation and pathologies in the hearts of mice. In this study, we examine the eyes of mice overexpressing wild-type Tmem135 (Tmem135 TG) and compare their phenotype to Tmem135 mutant mice. Methods Eyes were collected for histology, immunohistochemistry, electron microscopy, quantitative PCR, and Western blot analysis. Before tissue collection, electroretinography (ERG) was performed to assess visual function. Mouse retinal pigmented epithelium (RPE) cultures were established to visualize mitochondria. Results Pathologies were observed only in the RPE of Tmem135 TG mice, including degeneration, migratory cells, vacuolization, dysmorphogenesis, cell enlargement, and basal laminar deposit formation despite similar augmented levels of Tmem135 in the eyecup (RPE/choroid/sclera) and neural retina. We observed reduced mitochondria number and size in the Tmem135 TG RPE. ERG amplitudes were decreased in 365-day-old mice overexpressing Tmem135 that correlated with reduced expression of RPE cell markers. In Tmem135 mutant mice, RPE cells are thicker, smaller, and denser than their littermate controls without any signs of degeneration. Conclusions Overexpression and mutation of Tmem135 cause contrasting RPE abnormalities in mice that correlate with changes in mitochondrial shape and size (overfragmented in TG vs. overfused in mutant). We conclude proper regulation of mitochondrial homeostasis by TMEM135 is critical for RPE health.
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Affiliation(s)
- Michael Landowski
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, Wisconsin, United States
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, Wisconsin, United States
- Department of Pediatrics, Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Samuel Grindel
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Pawan K. Shahi
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, Wisconsin, United States
- Department of Pediatrics, Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Abigail Johnson
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Daniel Western
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Adrienne Race
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Franky Shi
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Jonathan Benson
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Marvin Gao
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Evelyn Santoirre
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Wei-Hua Lee
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Sakae Ikeda
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, Wisconsin, United States
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Bikash R. Pattnaik
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, Wisconsin, United States
- Department of Pediatrics, Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Akihiro Ikeda
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, Wisconsin, United States
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, Wisconsin, United States
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31
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Muñoz-Gómez SA, Snyder SN, Montoya SJ, Wideman JG. Independent accretion of TIM22 complex subunits in the animal and fungal lineages. F1000Res 2020; 9:1060. [PMID: 33014348 PMCID: PMC7523481 DOI: 10.12688/f1000research.25904.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/21/2020] [Indexed: 12/25/2022] Open
Abstract
Background: The mitochondrial protein import complexes arose early in eukaryogenesis. Most of the components of the protein import pathways predate the last eukaryotic common ancestor. For example, the carrier-insertase TIM22 complex comprises the widely conserved Tim22 channel core. However, the auxiliary components of fungal and animal TIM22 complexes are exceptions to this ancient conservation. Methods: Using comparative genomics and phylogenetic approaches, we identified precisely when each TIM22 accretion occurred. Results: In animals, we demonstrate that Tim29 and Tim10b arose early in the holozoan lineage. Tim29 predates the metazoan lineage being present in the animal sister lineages, choanoflagellate and filastereans, whereas the erroneously named Tim10b arose from a duplication of Tim9 at the base of metazoans. In fungi, we show that Tim54 has representatives present in every holomycotan lineage including microsporidians and fonticulids, whereas Tim18 and Tim12 appeared much later in fungal evolution. Specifically, Tim18 and Tim12 arose from duplications of Sdh3 and Tim10, respectively, early in the Saccharomycotina. Surprisingly, we show that Tim54 is distantly related to AGK suggesting that AGK and Tim54 are extremely divergent orthologues and the origin of AGK/Tim54 interaction with Tim22 predates the divergence of animals and fungi. Conclusions: We argue that the evolutionary history of the TIM22 complex is best understood as the neutral structural divergence of an otherwise strongly functionally conserved protein complex. This view suggests that many of the differences in structure/subunit composition of multi-protein complexes are non-adaptive. Instead, most of the phylogenetic variation of functionally conserved molecular machines, which have been under stable selective pressures for vast phylogenetic spans, such as the TIM22 complex, is most likely the outcome of the interplay of random genetic drift and mutation pressure.
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Affiliation(s)
- Sergio A. Muñoz-Gómez
- Biodesign Center for Mechanisms of Evolution, School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Shannon N. Snyder
- Biodesign Center for Mechanisms of Evolution, School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Samantha J. Montoya
- Biodesign Center for Mechanisms of Evolution, School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Jeremy G. Wideman
- Biodesign Center for Mechanisms of Evolution, School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
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32
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Horten P, Colina-Tenorio L, Rampelt H. Biogenesis of Mitochondrial Metabolite Carriers. Biomolecules 2020; 10:E1008. [PMID: 32645990 PMCID: PMC7408425 DOI: 10.3390/biom10071008] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/02/2020] [Accepted: 07/03/2020] [Indexed: 12/28/2022] Open
Abstract
: Metabolite carriers of the mitochondrial inner membrane are crucial for cellular physiology since mitochondria contribute essential metabolic reactions and synthesize the majority of the cellular ATP. Like almost all mitochondrial proteins, carriers have to be imported into mitochondria from the cytosol. Carrier precursors utilize a specialized translocation pathway dedicated to the biogenesis of carriers and related proteins, the carrier translocase of the inner membrane (TIM22) pathway. After recognition and import through the mitochondrial outer membrane via the translocase of the outer membrane (TOM) complex, carrier precursors are ushered through the intermembrane space by hexameric TIM chaperones and ultimately integrated into the inner membrane by the TIM22 carrier translocase. Recent advances have shed light on the mechanisms of TOM translocase and TIM chaperone function, uncovered an unexpected versatility of the machineries, and revealed novel components and functional crosstalk of the human TIM22 translocase.
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Affiliation(s)
- Patrick Horten
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (P.H.); (L.C.-T.)
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Lilia Colina-Tenorio
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (P.H.); (L.C.-T.)
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Heike Rampelt
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (P.H.); (L.C.-T.)
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
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33
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Schneider A. Evolution of mitochondrial protein import – lessons from trypanosomes. Biol Chem 2020; 401:663-676. [DOI: 10.1515/hsz-2019-0444] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 03/02/2020] [Indexed: 01/02/2023]
Abstract
AbstractThe evolution of mitochondrial protein import and the systems that mediate it marks the boundary between the endosymbiotic ancestor of mitochondria and a true organelle that is under the control of the nucleus. Protein import has been studied in great detail inSaccharomyces cerevisiae. More recently, it has also been extensively investigated in the parasitic protozoanTrypanosoma brucei, making it arguably the second best studied system. A comparative analysis of the protein import complexes of yeast and trypanosomes is provided. Together with data from other systems, this allows to reconstruct the ancestral features of import complexes that were present in the last eukaryotic common ancestor (LECA) and to identify which subunits were added later in evolution. How these data can be translated into plausible scenarios is discussed, providing insights into the evolution of (i) outer membrane protein import receptors, (ii) proteins involved in biogenesis of α-helically anchored outer membrane proteins, and (iii) of the intermembrane space import and assembly system. Finally, it is shown that the unusual presequence-associated import motor of trypanosomes suggests a scenario of how the two ancestral inner membrane protein translocases present in LECA evolved into the single bifunctional one found in extant trypanosomes.
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Affiliation(s)
- André Schneider
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
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Günsel U, Paz E, Gupta R, Mathes I, Azem A, Mokranjac D. InVivo Dissection of the Intrinsically Disordered Receptor Domain of Tim23. J Mol Biol 2020; 432:3326-3337. [PMID: 32277989 DOI: 10.1016/j.jmb.2020.03.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/05/2020] [Accepted: 03/31/2020] [Indexed: 01/11/2023]
Abstract
In the intermembrane space (IMS) of mitochondria, the receptor domain of Tim23 has an essential role during translocation of hundreds of different proteins from the cytosol via the TOM and TIM23 complexes in the outer and inner membranes, respectively. This intrinsically disordered domain, which can even extend into the cytosol, was shown, mostly in vitro, to interact with several subunits of the TOM and TIM23 complexes. To obtain molecular understanding of this organizational hub in the IMS, we dissected the IMS domain of Tim23 in vivo. We show that the interaction surface of Tim23 with Tim50 is larger than previously thought and reveal an unexpected interaction of Tim23 with Pam17 in the IMS, impairment of which influences their interaction in the matrix. Furthermore, mutations of two conserved negatively charged residues of Tim23, close to the inner membrane, prevented dimerization of Tim23. The same mutations increased exposure of Tim23 on the mitochondrial surface, whereas dissipation of membrane potential decreased it. Our results reveal an intricate network of Tim23 interactions in the IMS, whose influence is transduced across two mitochondrial membranes, ensuring efficient translocation of proteins into mitochondria.
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Affiliation(s)
- Umut Günsel
- BMC-Physiological Chemistry, LMU Munich, 82152 Martinsried, Germany
| | - Eyal Paz
- Department of Biochemistry and Molecular Biology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ruhita Gupta
- BMC-Physiological Chemistry, LMU Munich, 82152 Martinsried, Germany
| | | | - Abdussalam Azem
- Department of Biochemistry and Molecular Biology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Dejana Mokranjac
- BMC-Physiological Chemistry, LMU Munich, 82152 Martinsried, Germany.
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Matta SK, Kumar A, D'Silva P. Mgr2 regulates mitochondrial preprotein import by associating with channel-forming Tim23 subunit. Mol Biol Cell 2020; 31:1112-1123. [PMID: 32186971 PMCID: PMC7353164 DOI: 10.1091/mbc.e19-12-0677] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Mgr2, a newly identified subunit of the TIM23 complex, functions as a gatekeeper of presequence translocase and thereby maintains quality control of inner membrane preproteins sorting. However, precise recruitment of the Mgr2 subunit to the core channel and how it influences the assembly of the TIM23 complex during lateral sorting of preproteins are poorly understood. Present findings provide insights into a direct association of Mgr2 with the channel-forming Tim23 subunit. Furthermore, the mutational analysis uncovers the TM1 region of Mgr2 critically required for association with Tim23 and Tim21. On the other hand, the TM2 region of Mgr2 is involved in bridging respiratory complexes to the TIM23 complex via Tim21. Importantly, both TM regions of Mgr2 are essential for lateral sorting of preprotein into the inner membrane, as well as maintaining mitochondrial morphology. Together, our findings provide mechanistic insights into the role of Mgr2 in regulating the dynamicity of the TIM23 complex assembly required for preprotein import and coupling of respiratory pathways.
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Affiliation(s)
- Srujan Kumar Matta
- Department of Biochemistry, New Biological Sciences Building, Indian Institute of Science, Bangalore-560012, India
| | - Abhishek Kumar
- Department of Biochemistry, New Biological Sciences Building, Indian Institute of Science, Bangalore-560012, India
| | - Patrick D'Silva
- Department of Biochemistry, New Biological Sciences Building, Indian Institute of Science, Bangalore-560012, India
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36
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Gray MW, Burger G, Derelle R, Klimeš V, Leger MM, Sarrasin M, Vlček Č, Roger AJ, Eliáš M, Lang BF. The draft nuclear genome sequence and predicted mitochondrial proteome of Andalucia godoyi, a protist with the most gene-rich and bacteria-like mitochondrial genome. BMC Biol 2020; 18:22. [PMID: 32122349 PMCID: PMC7050145 DOI: 10.1186/s12915-020-0741-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 01/21/2020] [Indexed: 01/02/2023] Open
Abstract
Background Comparative analyses have indicated that the mitochondrion of the last eukaryotic common ancestor likely possessed all the key core structures and functions that are widely conserved throughout the domain Eucarya. To date, such studies have largely focused on animals, fungi, and land plants (primarily multicellular eukaryotes); relatively few mitochondrial proteomes from protists (primarily unicellular eukaryotic microbes) have been examined. To gauge the full extent of mitochondrial structural and functional complexity and to identify potential evolutionary trends in mitochondrial proteomes, more comprehensive explorations of phylogenetically diverse mitochondrial proteomes are required. In this regard, a key group is the jakobids, a clade of protists belonging to the eukaryotic supergroup Discoba, distinguished by having the most gene-rich and most bacteria-like mitochondrial genomes discovered to date. Results In this study, we assembled the draft nuclear genome sequence for the jakobid Andalucia godoyi and used a comprehensive in silico approach to infer the nucleus-encoded portion of the mitochondrial proteome of this protist, identifying 864 candidate mitochondrial proteins. The A. godoyi mitochondrial proteome has a complexity that parallels that of other eukaryotes, while exhibiting an unusually large number of ancestral features that have been lost particularly in opisthokont (animal and fungal) mitochondria. Notably, we find no evidence that the A. godoyi nuclear genome has or had a gene encoding a single-subunit, T3/T7 bacteriophage-like RNA polymerase, which functions as the mitochondrial transcriptase in all eukaryotes except the jakobids. Conclusions As genome and mitochondrial proteome data have become more widely available, a strikingly punctuate phylogenetic distribution of different mitochondrial components has been revealed, emphasizing that the pathways of mitochondrial proteome evolution are likely complex and lineage-specific. Unraveling this complexity will require comprehensive comparative analyses of mitochondrial proteomes from a phylogenetically broad range of eukaryotes, especially protists. The systematic in silico approach described here offers a valuable adjunct to direct proteomic analysis (e.g., via mass spectrometry), particularly in cases where the latter approach is constrained by sample limitation or other practical considerations.
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Affiliation(s)
- Michael W Gray
- Department of Biochemistry and Molecular Biology and Centre for Comparative Genomics and Evolutionary Bioinformatics, Sir Charles Tupper Medical Building, Dalhousie University, 5850 College Street, Halifax, Nova Scotia, B3H 4R2, Canada.
| | - Gertraud Burger
- Département de Biochimie and Robert-Cedergren Center for Bioinformatics and Genomics, Université de Montréal, Montréal, QC, Canada
| | - Romain Derelle
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Vladimír Klimeš
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Michelle M Leger
- Department of Biochemistry and Molecular Biology and Centre for Comparative Genomics and Evolutionary Bioinformatics, Sir Charles Tupper Medical Building, Dalhousie University, 5850 College Street, Halifax, Nova Scotia, B3H 4R2, Canada.,Institute of Evolutionary Biology (CSIC-UPF), Barcelona, Spain
| | - Matt Sarrasin
- Département de Biochimie and Robert-Cedergren Center for Bioinformatics and Genomics, Université de Montréal, Montréal, QC, Canada
| | - Čestmír Vlček
- Current address: Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Andrew J Roger
- Department of Biochemistry and Molecular Biology and Centre for Comparative Genomics and Evolutionary Bioinformatics, Sir Charles Tupper Medical Building, Dalhousie University, 5850 College Street, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Marek Eliáš
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - B Franz Lang
- Département de Biochimie and Robert-Cedergren Center for Bioinformatics and Genomics, Université de Montréal, Montréal, QC, Canada
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37
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von Känel C, Muñoz-Gómez SA, Oeljeklaus S, Wenger C, Warscheid B, Wideman JG, Harsman A, Schneider A. Homologue replacement in the import motor of the mitochondrial inner membrane of trypanosomes. eLife 2020; 9:52560. [PMID: 32105215 PMCID: PMC7064343 DOI: 10.7554/elife.52560] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 02/26/2020] [Indexed: 01/13/2023] Open
Abstract
Many mitochondrial proteins contain N-terminal presequences that direct them to the organelle. The main driving force for their translocation across the inner membrane is provided by the presequence translocase-associated motor (PAM) which contains the J-protein Pam18. Here, we show that in the PAM of Trypanosoma brucei the function of Pam18 has been replaced by the non-orthologous euglenozoan-specific J-protein TbPam27. TbPam27 is specifically required for the import of mitochondrial presequence-containing but not for carrier proteins. Similar to yeast Pam18, TbPam27 requires an intact J-domain to function. Surprisingly, T. brucei still contains a bona fide Pam18 orthologue that, while essential for normal growth, is not involved in protein import. Thus, during evolution of kinetoplastids, Pam18 has been replaced by TbPam27. We propose that this replacement is linked to the transition from two ancestral and functionally distinct TIM complexes, found in most eukaryotes, to the single bifunctional TIM complex present in trypanosomes.
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Affiliation(s)
- Corinne von Känel
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
| | - Sergio A Muñoz-Gómez
- Center for Mechanisms of Evolution, Biodesign Institute, School of Life Sciences, Arizona State University, Tempe, United States
| | - Silke Oeljeklaus
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology and Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Christoph Wenger
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
| | - Bettina Warscheid
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology and Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Jeremy G Wideman
- Center for Mechanisms of Evolution, Biodesign Institute, School of Life Sciences, Arizona State University, Tempe, United States
| | - Anke Harsman
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
| | - Andre Schneider
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
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Amini MA, Talebi SS, Karimi J. Reactive Oxygen Species Modulator 1 (ROMO1), a New Potential Target for Cancer Diagnosis and Treatment. Chonnam Med J 2019; 55:136-143. [PMID: 31598470 PMCID: PMC6769249 DOI: 10.4068/cmj.2019.55.3.136] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 06/14/2019] [Accepted: 06/19/2019] [Indexed: 02/01/2023] Open
Abstract
Today, the incidence of cancer in the world is rising, and it is expected that in the next several decades, the number of people suffering from cancer or (the cancer rate) will double. Cancer is defined as the excessive and uncontrolled growth of cells; of course (in simple terms), cancer is considered to be a set of other diseases that ultimately causes normal cells to be transformed into neoplastic cells. One of the most important causes of the onset and exacerbation of cancer is excessive oxidative stress. One of the most important proteins in the inner membrane of mitochondria is Reactive Oxygen Species (ROS) Modulator 1 (ROMO1) that interferes with the production of ROS, and with increasing the rate of this protein, oxidative stress will increase, which ultimately leads to some diseases, especially cancer. In this overview, we use some global databases to provide information about ROMO1 cellular signaling pathways, their related proteins and molecules, and some of the diseases associated with the mitochondrial protein, especially cancer.
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Affiliation(s)
- Mohammad Amin Amini
- Department of Clinical Biochemistry, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Seyed Saman Talebi
- Department of Internal Medicine, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Jamshid Karimi
- Department of Clinical Biochemistry, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
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39
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Mitochondrial presequence import: Multiple regulatory knobs fine-tune mitochondrial biogenesis and homeostasis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1866:930-944. [PMID: 30802482 DOI: 10.1016/j.bbamcr.2019.02.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 02/14/2019] [Accepted: 02/19/2019] [Indexed: 12/22/2022]
Abstract
Mitochondria are pivotal organelles for cellular signaling and metabolism, and their dysfunction leads to severe cellular stress. About 60-70% of the mitochondrial proteome consists of preproteins synthesized in the cytosol with an amino-terminal cleavable presequence targeting signal. The TIM23 complex transports presequence signals towards the mitochondrial matrix. Ultimately, the mature protein segments are either transported into the matrix or sorted to the inner membrane. To ensure accurate preprotein import into distinct mitochondrial sub-compartments, the TIM23 machinery adopts specific functional conformations and interacts with different partner complexes. Regulatory subunits modulate the translocase dynamics, tailoring the import reaction to the incoming preprotein. The mitochondrial membrane potential and the ATP generated via oxidative phosphorylation are key energy sources in driving the presequence import pathway. Thus, mitochondrial dysfunctions have rapid repercussions on biogenesis. Cellular mechanisms exploit the presequence import pathway to monitor mitochondrial dysfunctions and mount transcriptional and proteostatic responses to restore functionality.
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40
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Richter F, Dennerlein S, Nikolov M, Jans DC, Naumenko N, Aich A, MacVicar T, Linden A, Jakobs S, Urlaub H, Langer T, Rehling P. ROMO1 is a constituent of the human presequence translocase required for YME1L protease import. J Cell Biol 2018; 218:598-614. [PMID: 30598479 PMCID: PMC6363466 DOI: 10.1083/jcb.201806093] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 10/18/2018] [Accepted: 11/26/2018] [Indexed: 01/15/2023] Open
Abstract
Mitochondria are the powerhouses of eukaryotic cells and rely on protein import from the cytosol. Richter et al. found ROMO1 as a new constituent of the human mitochondrial import machinery linking protein import to quality control and mitochondrial morphology. The mitochondrial presequence translocation machinery (TIM23 complex) is conserved between the yeast Saccharomyces cerevisiae and humans; however, functional characterization has been mainly performed in yeast. Here, we define the constituents of the human TIM23 complex using mass spectrometry and identified ROMO1 as a new translocase constituent with an exceptionally short half-life. Analyses of a ROMO1 knockout cell line revealed aberrant inner membrane structure and altered processing of the GTPase OPA1. We show that in the absence of ROMO1, mitochondria lose the inner membrane YME1L protease, which participates in OPA1 processing and ROMO1 turnover. While ROMO1 is dispensable for general protein import along the presequence pathway, we show that it participates in the dynamics of TIM21 during respiratory chain biogenesis and is specifically required for import of YME1L. This selective import defect can be linked to charge distribution in the unusually long targeting sequence of YME1L. Our analyses establish an unexpected link between mitochondrial protein import and inner membrane protein quality control.
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Affiliation(s)
- Frank Richter
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Sven Dennerlein
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Miroslav Nikolov
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Daniel C Jans
- Department of NanoBiophotonics, Mitochondrial Structure and Dynamics Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Department of Neurology, University Medical Center, Göttingen, Germany
| | - Nataliia Naumenko
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Abhishek Aich
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Thomas MacVicar
- Department of Mitochondrial Proteostasis, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Andreas Linden
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Bioanalytics Group, Department of Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Stefan Jakobs
- Department of NanoBiophotonics, Mitochondrial Structure and Dynamics Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Department of Neurology, University Medical Center, Göttingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Bioanalytics Group, Department of Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Thomas Langer
- Department of Mitochondrial Proteostasis, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Peter Rehling
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany .,Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
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Long non-coding RNA TCF7 contributes to the growth and migration of airway smooth muscle cells in asthma through targeting TIMMDC1/Akt axis. Biochem Biophys Res Commun 2018; 508:749-755. [PMID: 30528236 DOI: 10.1016/j.bbrc.2018.11.187] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 11/28/2018] [Indexed: 01/15/2023]
Abstract
BACKGROUND Long noncoding RNAs (lncRNAs) have been revealed to participate in cellular biological processes in multiple diseases, including asthma. Nevertheless, the role of lncRNA TCF7 (lncTCF7) in airway smooth muscle cells (ASMCs) is still covered. METHODS The expression of lncTCF7 and TIMMDC1 in ASMCs from 12 asthma patients and 12 healthy controls were detected using qRT-PCR. Then MTT assay, EdU assay and transwell assay were conducted respectively to assess the impact of lncTCF7 on ASMCs viability, proliferation and migration. Besides, western blotting was performed to determine the protein levels of TIMMDC1 and AKT/p-AKT. RESULTS We discovered that lncTCF7 and TIMMDC1 were upregulated in asthma groups and lncTCF7 improved ASMCs viability/proliferation and migration. In addition, lncTCF7 regulated TIMMDC1 expression indeed and PDGF-BB treated ASMCs exhibited elevated levels of lncTCF7 and TIMMDC1. Moreover, lncTCF7 suppression diminished both the mRNA and protein levels of TIMMDC1 and markedly reduced p-AKT level which could be enhanced under TIMMDC1 overexpression. Finally, both TIMMDC1 overexpression and AKT activator could restored the inhibitory impacts of lncTCF7 silence on PDGF-BB treated ASMCs. CONCLUSION Our study uncovered that lncTCF7 facilitated human ASMCs growth and migration via targeting TIMMDC1 thus activating AKT signaling, providing a novel possible target for asthma therapy.
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42
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Petrů M, Wideman J, Moore K, Alcock F, Palmer T, Doležal P. Evolution of mitochondrial TAT translocases illustrates the loss of bacterial protein transport machines in mitochondria. BMC Biol 2018; 16:141. [PMID: 30466434 PMCID: PMC6251230 DOI: 10.1186/s12915-018-0607-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 11/01/2018] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Bacteria and mitochondria contain translocases that function to transport proteins across or insert proteins into their inner and outer membranes. Extant mitochondria retain some bacterial-derived translocases but have lost others. While BamA and YidC were integrated into general mitochondrial protein transport pathways (as Sam50 and Oxa1), the inner membrane TAT translocase, which uniquely transports folded proteins across the membrane, was retained sporadically across the eukaryote tree. RESULTS We have identified mitochondrial TAT machinery in diverse eukaryotic lineages and define three different types of eukaryote-encoded TatABC-derived machineries (TatAC, TatBC and TatC-only). Here, we investigate TatAC and TatC-only machineries, which have not been studied previously. We show that mitochondria-encoded TatAC of the jakobid Andalucia godoyi represent the minimal functional pathway capable of substituting for the Escherichia coli TatABC complex and can transport at least one substrate. However, selected TatC-only machineries, from multiple eukaryotic lineages, were not capable of supporting the translocation of this substrate across the bacterial membrane. Despite the multiple losses of the TatC gene from the mitochondrial genome, the gene was never transferred to the cell nucleus. Although the major constraint preventing nuclear transfer of mitochondrial TatC is likely its high hydrophobicity, we show that in chloroplasts, such transfer of TatC was made possible due to modifications of the first transmembrane domain. CONCLUSIONS At its origin, mitochondria inherited three inner membrane translocases Sec, TAT and Oxa1 (YidC) from its bacterial ancestor. Our work shows for the first time that mitochondrial TAT has likely retained its unique function of transporting folded proteins at least in those few eukaryotes with TatA and TatC subunits encoded in the mitochondrial genome. However, mitochondria, in contrast to chloroplasts, abandoned the machinery multiple times in evolution. The overall lower hydrophobicity of the Oxa1 protein was likely the main reason why this translocase was nearly universally retained in mitochondrial biogenesis pathways.
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Affiliation(s)
- Markéta Petrů
- Department of Parasitology, Faculty of Science, BIOCEV, Charles University, Průmyslová 595, 252 50, Vestec, Czech Republic
| | - Jeremy Wideman
- Wissenschaftskolleg zu Berlin, Wallotstrasse 19, 14193, Berlin, Germany
- Department of Biochemistry and Molecular Biology, Dalhousie University, PO Box 15000, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Kristoffer Moore
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Felicity Alcock
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Tracy Palmer
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Pavel Doležal
- Department of Parasitology, Faculty of Science, BIOCEV, Charles University, Průmyslová 595, 252 50, Vestec, Czech Republic.
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Abstract
Peroxisomes are key metabolic organelles, which contribute to cellular lipid metabolism, e.g. the β-oxidation of fatty acids and the synthesis of myelin sheath lipids, as well as cellular redox balance. Peroxisomal dysfunction has been linked to severe metabolic disorders in man, but peroxisomes are now also recognized as protective organelles with a wider significance in human health and potential impact on a large number of globally important human diseases such as neurodegeneration, obesity, cancer, and age-related disorders. Therefore, the interest in peroxisomes and their physiological functions has significantly increased in recent years. In this review, we intend to highlight recent discoveries, advancements and trends in peroxisome research, and present an update as well as a continuation of two former review articles addressing the unsolved mysteries of this astonishing organelle. We summarize novel findings on the biological functions of peroxisomes, their biogenesis, formation, membrane dynamics and division, as well as on peroxisome-organelle contacts and cooperation. Furthermore, novel peroxisomal proteins and machineries at the peroxisomal membrane are discussed. Finally, we address recent findings on the role of peroxisomes in the brain, in neurological disorders, and in the development of cancer.
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Affiliation(s)
- Markus Islinger
- Institute of Neuroanatomy, Center for Biomedicine and Medical Technology Mannheim, Medical Faculty Manheim, University of Heidelberg, 68167, Mannheim, Germany
| | - Alfred Voelkl
- Institute for Anatomy and Cell Biology, University of Heidelberg, 69120, Heidelberg, Germany
| | - H Dariush Fahimi
- Institute for Anatomy and Cell Biology, University of Heidelberg, 69120, Heidelberg, Germany
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Pyrihová E, Motycková A, Voleman L, Wandyszewska N, Fišer R, Seydlová G, Roger A, Kolísko M, Doležal P. A Single Tim Translocase in the Mitosomes of Giardia intestinalis Illustrates Convergence of Protein Import Machines in Anaerobic Eukaryotes. Genome Biol Evol 2018; 10:2813-2822. [PMID: 30265292 PMCID: PMC6200312 DOI: 10.1093/gbe/evy215] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2018] [Indexed: 11/14/2022] Open
Abstract
Mitochondria have evolved diverse forms across eukaryotic diversity in adaptation to anoxia. Mitosomes are the simplest and the least well-studied type of anaerobic mitochondria. Transport of proteins via TIM complexes, composed of three proteins of the Tim17 protein family (Tim17/22/23), is one of the key unifying aspects of mitochondria and mitochondria-derived organelles. However, multiple experimental and bioinformatic attempts have so far failed to identify the nature of TIM in mitosomes of the anaerobic metamonad protist, Giardia intestinalis, one of the few experimental models for mitosome biology. Here, we present the identification of a single G. intestinalis Tim17 protein (GiTim17), made possible only by the implementation of a metamonad-specific hidden Markov model. While very divergent in primary sequence and in predicted membrane topology, experimental data suggest that GiTim17 is an inner membrane mitosomal protein, forming a disulphide-linked dimer. We suggest that the peculiar GiTim17 sequence reflects adaptation to the unusual, detergent resistant, inner mitosomal membrane. Specific pull-down experiments indicate interaction of GiTim17 with mitosomal Tim44, the tethering component of the import motor complex. Analysis of TIM complexes across eukaryote diversity suggests that a "single Tim" translocase is a convergent adaptation of mitosomes in anaerobic protists, with Tim22 and Tim17 (but not Tim23), providing the protein backbone.
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Affiliation(s)
- Eva Pyrihová
- Department of Parasitology, Faculty of Science, Charles University, Vestec, Czech Republic
| | - Alžbeta Motycková
- Department of Parasitology, Faculty of Science, Charles University, Vestec, Czech Republic
| | - Luboš Voleman
- Department of Parasitology, Faculty of Science, Charles University, Vestec, Czech Republic
| | - Natalia Wandyszewska
- Department of Parasitology, Faculty of Science, Charles University, Vestec, Czech Republic
| | - Radovan Fišer
- Department of Genetics and Microbiology, Charles University, Praha 2, Czech Republic
| | - Gabriela Seydlová
- Department of Genetics and Microbiology, Charles University, Praha 2, Czech Republic
| | - Andrew Roger
- Centre for Comparative Genomics and Evolutionary Bioinformatics, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada
| | - Martin Kolísko
- Centre for Comparative Genomics and Evolutionary Bioinformatics, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada.,Biology Centre CAS, České Budějovice, Czech Republic
| | - Pavel Doležal
- Department of Parasitology, Faculty of Science, Charles University, Vestec, Czech Republic
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45
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Plant mitochondrial protein import: the ins and outs. Biochem J 2018; 475:2191-2208. [PMID: 30018142 DOI: 10.1042/bcj20170521] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 06/19/2018] [Accepted: 06/21/2018] [Indexed: 01/29/2023]
Abstract
The majority of the mitochondrial proteome, required to fulfil its diverse range of functions, is cytosolically synthesised and translocated via specialised machinery. The dedicated translocases, receptors, and associated proteins have been characterised in great detail in yeast over the last several decades, yet many of the mechanisms that regulate these processes in higher eukaryotes are still unknown. In this review, we highlight the current knowledge of mitochondrial protein import in plants. Despite the fact that the mechanisms of mitochondrial protein import have remained conserved across species, many unique features have arisen in plants to encompass the developmental, tissue-specific, and stress-responsive regulation in planta. An understanding of unique features and mechanisms in plants provides us with a unique insight into the regulation of mitochondrial biogenesis in higher eukaryotes.
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46
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Backes S, Herrmann JM. Protein Translocation into the Intermembrane Space and Matrix of Mitochondria: Mechanisms and Driving Forces. Front Mol Biosci 2017; 4:83. [PMID: 29270408 PMCID: PMC5725982 DOI: 10.3389/fmolb.2017.00083] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 11/24/2017] [Indexed: 11/17/2022] Open
Abstract
Mitochondria contain two aqueous subcompartments, the matrix and the intermembrane space (IMS). The matrix is enclosed by both the inner and outer mitochondrial membranes, whilst the IMS is sandwiched between the two. Proteins of the matrix are synthesized in the cytosol as preproteins, which contain amino-terminal matrix targeting sequences that mediate their translocation through translocases embedded in the outer and inner membrane. For these proteins, the translocation reaction is driven by the import motor which is part of the inner membrane translocase. The import motor employs matrix Hsp70 molecules and ATP hydrolysis to ratchet proteins into the mitochondrial matrix. Most IMS proteins lack presequences and instead utilize the IMS receptor Mia40, which facilitates their translocation across the outer membrane in a reaction that is coupled to the formation of disulfide bonds within the protein. This process requires neither ATP nor the mitochondrial membrane potential. Mia40 fulfills two roles: First, it acts as a holdase, which is crucial in the import of IMS proteins and second, it functions as a foldase, introducing disulfide bonds into newly imported proteins, which induces and stabilizes their natively folded state. For several Mia40 substrates, oxidative folding is an essential prerequisite for their assembly into oligomeric complexes. Interestingly, recent studies have shown that the two functions of Mia40 can be experimentally separated from each other by the use of specific mutants, hence providing a powerful new way to dissect the different physiological roles of Mia40. In this review we summarize the current knowledge relating to the mitochondrial matrix-targeting and the IMS-targeting/Mia40 pathway. Moreover, we discuss the mechanistic properties by which the mitochondrial import motor on the one hand and Mia40 on the other, drive the translocation of their substrates into the organelle. We propose that the lateral diffusion of Mia40 in the inner membrane and the oxidation-mediated folding of incoming polypeptides supports IMS import.
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Affiliation(s)
- Sandra Backes
- Cell Biology, University of Kaiserslautern, Kaiserslautern, Germany
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Kang Y, Fielden LF, Stojanovski D. Mitochondrial protein transport in health and disease. Semin Cell Dev Biol 2017; 76:142-153. [PMID: 28765093 DOI: 10.1016/j.semcdb.2017.07.028] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 07/18/2017] [Accepted: 07/19/2017] [Indexed: 01/17/2023]
Abstract
Mitochondria are fundamental structures that fulfil important and diverse functions within cells, including cellular respiration and iron-sulfur cluster biogenesis. Mitochondrial function is reliant on the organelles proteome, which is maintained and adjusted depending on cellular requirements. The majority of mitochondrial proteins are encoded by nuclear genes and must be trafficked to, and imported into the organelle following synthesis in the cytosol. These nuclear-encoded mitochondrial precursors utilise dynamic and multimeric translocation machines to traverse the organelles membranes and be partitioned to the appropriate mitochondrial subcompartment. Yeast model systems have been instrumental in establishing the molecular basis of mitochondrial protein import machines and mechanisms, however unique players and mechanisms are apparent in higher eukaryotes. Here, we review our current knowledge on mitochondrial protein import in human cells and how dysfunction in these pathways can lead to disease.
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Affiliation(s)
- Yilin Kang
- Department of Biochemistry and Molecular Biology and The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Laura F Fielden
- Department of Biochemistry and Molecular Biology and The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Diana Stojanovski
- Department of Biochemistry and Molecular Biology and The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, 3010, Australia.
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