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Dinh N, Bonnefoy N. Schizosaccharomyces pombe as a fundamental model for research on mitochondrial gene expression: Progress, achievements and outlooks. IUBMB Life 2023. [PMID: 38117001 DOI: 10.1002/iub.2801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 11/17/2023] [Indexed: 12/21/2023]
Abstract
Schizosaccharomyces pombe (fission yeast) is an attractive model for mitochondrial research. The organism resembles human cells in terms of mitochondrial inheritance, mitochondrial transport, sugar metabolism, mitogenome structure and dependence of viability on the mitogenome (the petite-negative phenotype). Transcriptions of these genomes produce only a few polycistronic transcripts, which then undergo processing as per the tRNA punctuation model. In general, the machinery for mitochondrial gene expression is structurally and functionally conserved between fission yeast and humans. Furthermore, molecular research on S. pombe is supported by a considerable number of experimental techniques and database resources. Owing to these advantages, fission yeast has significantly contributed to biomedical and fundamental research. Here, we review the current state of knowledge regarding S. pombe mitochondrial gene expression, and emphasise the pertinence of fission yeast as both a model and tool, especially for studies on mitochondrial translation.
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Affiliation(s)
- Nhu Dinh
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette cedex, France
| | - Nathalie Bonnefoy
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette cedex, France
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2
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Xin N, Durieux J, Yang C, Wolff S, Kim HE, Dillin A. The UPRmt preserves mitochondrial import to extend lifespan. J Cell Biol 2022; 221:e202201071. [PMID: 35608535 PMCID: PMC9134095 DOI: 10.1083/jcb.202201071] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 04/14/2022] [Accepted: 04/26/2022] [Indexed: 01/07/2023] Open
Abstract
The mitochondrial unfolded protein response (UPRmt) is dedicated to promoting mitochondrial proteostasis and is linked to extreme longevity. The key regulator of this process is the transcription factor ATFS-1, which, upon UPRmt activation, is excluded from the mitochondria and enters the nucleus to regulate UPRmt genes. However, the repair proteins synthesized as a direct result of UPRmt activation must be transported into damaged mitochondria that had previously excluded ATFS-1 owing to reduced import efficiency. To address this conundrum, we analyzed the role of the import machinery when the UPRmt was induced. Using in vitro and in vivo analysis of mitochondrial proteins, we surprisingly find that mitochondrial import increases when the UPRmt is activated in an ATFS-1-dependent manner, despite reduced mitochondrial membrane potential. The import machinery is upregulated, and an intact import machinery is essential for UPRmt-mediated lifespan extension. ATFS-1 has a weak mitochondrial targeting sequence (MTS), allowing for dynamic subcellular localization during the initial stages of UPRmt activation.
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Affiliation(s)
- Nan Xin
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA
- Department of Integrated Biology and Pharmacology, University of Texas, Health Science Center, Houston, TX
| | - Jenni Durieux
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA
| | - Chunxia Yang
- Department of Integrated Biology and Pharmacology, University of Texas, Health Science Center, Houston, TX
| | - Suzanne Wolff
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA
| | - Hyun-Eui Kim
- Department of Integrated Biology and Pharmacology, University of Texas, Health Science Center, Houston, TX
| | - Andrew Dillin
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA
- Howard Hughes Medical Institute, Chevy Chase, MD
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3
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Friedl J, Knopp MR, Groh C, Paz E, Gould SB, Herrmann JM, Boos F. More than just a ticket canceller: the mitochondrial processing peptidase tailors complex precursor proteins at internal cleavage sites. Mol Biol Cell 2020; 31:2657-2668. [PMID: 32997570 PMCID: PMC8734313 DOI: 10.1091/mbc.e20-08-0524] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 09/21/2020] [Accepted: 09/25/2020] [Indexed: 11/11/2022] Open
Abstract
Most mitochondrial proteins are synthesized as precursors that carry N-terminal presequences. After they are imported into mitochondria, these targeting signals are cleaved off by the mitochondrial processing peptidase (MPP). Using the mitochondrial tandem protein Arg5,6 as a model substrate, we demonstrate that MPP has an additional role in preprotein maturation, beyond the removal of presequences. Arg5,6 is synthesized as a polyprotein precursor that is imported into mitochondria and subsequently separated into two distinct enzymes. This internal processing is performed by MPP, which cleaves the Arg5,6 precursor at its N-terminus and at an internal site. The peculiar organization of Arg5,6 is conserved across fungi and reflects the polycistronic arginine operon in prokaryotes. MPP cleavage sites are also present in other mitochondrial fusion proteins from fungi, plants, and animals. Hence, besides its role as a "ticket canceller" for removal of presequences, MPP exhibits a second conserved activity as an internal processing peptidase for complex mitochondrial precursor proteins.
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Affiliation(s)
- Jana Friedl
- Cell Biology, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Michael R. Knopp
- Molecular Evolution, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Carina Groh
- Cell Biology, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Eyal Paz
- Departments of Biochemistry and Molecular Biology, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Sven B. Gould
- Molecular Evolution, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Johannes M. Herrmann
- Cell Biology, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Felix Boos
- Cell Biology, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
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4
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Holič R, Pokorná L, Griač P. Metabolism of phospholipids in the yeast
Schizosaccharomyces pombe. Yeast 2019; 37:73-92. [DOI: 10.1002/yea.3451] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 11/26/2019] [Accepted: 11/27/2019] [Indexed: 12/28/2022] Open
Affiliation(s)
- Roman Holič
- Centre of Biosciences, Slovak Academy of Sciences Institute of Animal Biochemistry and Genetics Dúbravská cesta 9 Bratislava Slovakia
| | - Lucia Pokorná
- Centre of Biosciences, Slovak Academy of Sciences Institute of Animal Biochemistry and Genetics Dúbravská cesta 9 Bratislava Slovakia
| | - Peter Griač
- Centre of Biosciences, Slovak Academy of Sciences Institute of Animal Biochemistry and Genetics Dúbravská cesta 9 Bratislava Slovakia
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5
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Bohovych I, Dietz JV, Swenson S, Zahayko N, Khalimonchuk O. Redox Regulation of the Mitochondrial Quality Control Protease Oma1. Antioxid Redox Signal 2019; 31:429-443. [PMID: 31044600 PMCID: PMC6653804 DOI: 10.1089/ars.2018.7642] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Aims: Normal mitochondrial function and integrity are crucial for cellular physiology. Given the paramount role of mitochondrial quality control proteases in these processes, our study focused on investigating mechanisms by which the activity of a key quality control protease Oma1 is regulated under normal conditions and in response to homeostatic insults. Results: Oma1 was found to be a redox-dependent protein that exists in a semi-oxidized state in yeast and mammalian mitochondria. Biochemical and genetic analyses provide evidence that activity and stability of the Oma1 oligomeric complex can be dynamically tuned in a reduction/oxidation-sensitive manner. Mechanistically, these features appear to be mediated by two intermembrane space (IMS)-exposed highly conserved cysteine residues, Cys272 and Cys332. These residues form a disulfide bond, which likely plays a structural role and influences conformational stability and activity of the Oma1 high-mass complex. Finally, in line with these findings, engineered Oma1 substrate is shown to engage with the protease in a redox-sensitive manner. Innovation: This study provides new insights into the function of the Oma1 protease, a central controller of mitochondrial membrane homeostasis and dynamics, and reveals the novel conserved mechanism of the redox-dependent regulation of Oma1. Conclusion: Disulfide bonds formed by IMS-exposed residues Cys272 and Cys332 play an important evolutionarily conserved role in the regulation of Oma1 function. We propose that the redox status of these cysteines may act as a redox-tunable switch to optimize Oma1 proteolytic function for specific cellular conditions or homeostatic challenges.
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Affiliation(s)
- Iryna Bohovych
- 1 Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska
| | - Jonathan V Dietz
- 1 Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska
| | - Samantha Swenson
- 1 Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska
| | - Nataliya Zahayko
- 1 Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska
| | - Oleh Khalimonchuk
- 1 Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska.,2 Nebraska Redox Biology Center, University of Nebraska-Lincoln, Lincoln, Nebraska.,3 Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, Nebraska.,4 Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska
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6
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Virčíková V, Pokorná L, Tahotná D, Džugasová V, Balážová M, Griač P. Schizosaccharomyces pombe cardiolipin synthase is part of a mitochondrial fusion protein regulated by intron retention. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1863:1331-1344. [PMID: 29958934 DOI: 10.1016/j.bbalip.2018.06.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 06/08/2018] [Accepted: 06/23/2018] [Indexed: 11/29/2022]
Abstract
Cardiolipin (CL) is a unique lipid component of mitochondria in all eukaryotes. It is important for the architecture of mitochondrial membranes and for mitochondrial dynamics. CL also creates a highly specific microenvironment of mitochondrial protein machineries. CL biosynthetic pathway is, however, only partially characterized in the fission yeast Schizosaccharomyces pombe. Here we show that CL synthase is an essential protein in S. pombe. It is encoded by the ORF SPAC22A12.08c as a C terminal part of a tandem fusion protein together with a mitochondrial hydrolase of unknown function. Expression of S. pombe CL synthase is able to complement deletion of the CRD1 gene of Saccharomyces cerevisiae and, vice versa, S. cerevisiae CRD1 gene complements deletion of S. pombe SPAC22A12.08c. The proper expression of CL synthase and its partner in the tandem protein, the mitochondrial hydrolase, is regulated at the level of alternate intron splicing. The first part of the SPAC22A12.08c fusion protein could be translated from both major SPAC22A12.08c derived mRNAs, with and without intron IV. Functional CL synthase, however, is produced only from the minor SPAC22A12.08c derived mRNA that has intron IV retained. Thus, intron retention is a novel mechanism for the differential expression of two proteins that evolved as a fusion protein and are under the control of the same promoter.
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Affiliation(s)
- Veronika Virčíková
- Centre of Biosciences, Institute of Animal Biochemistry and Genetics, Slovak Academy of Sciences, Dúbravská cesta 9, 840 05 Bratislava, Slovakia
| | - Lucia Pokorná
- Centre of Biosciences, Institute of Animal Biochemistry and Genetics, Slovak Academy of Sciences, Dúbravská cesta 9, 840 05 Bratislava, Slovakia
| | - Dana Tahotná
- Centre of Biosciences, Institute of Animal Biochemistry and Genetics, Slovak Academy of Sciences, Dúbravská cesta 9, 840 05 Bratislava, Slovakia
| | - Vladimíra Džugasová
- Department of Genetics, Faculty of Natural Sciences, Comenius University, Ilkovičova 6, 842 15 Bratislava, Slovakia
| | - Mária Balážová
- Centre of Biosciences, Institute of Animal Biochemistry and Genetics, Slovak Academy of Sciences, Dúbravská cesta 9, 840 05 Bratislava, Slovakia
| | - Peter Griač
- Centre of Biosciences, Institute of Animal Biochemistry and Genetics, Slovak Academy of Sciences, Dúbravská cesta 9, 840 05 Bratislava, Slovakia.
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7
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Backes S, Hess S, Boos F, Woellhaf MW, Gödel S, Jung M, Mühlhaus T, Herrmann JM. Tom70 enhances mitochondrial preprotein import efficiency by binding to internal targeting sequences. J Cell Biol 2018; 217:1369-1382. [PMID: 29382700 PMCID: PMC5881500 DOI: 10.1083/jcb.201708044] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 12/12/2017] [Accepted: 01/17/2018] [Indexed: 11/22/2022] Open
Abstract
N-terminal matrix-targeting signals (MTSs) are critical for mitochondrial protein import. Backes et al. identified additional internal MTS-like sequences scattered along the sequences of mitochondrial proteins. By binding to Tom70 on the mitochondrial surface, these sequences support the import process. The biogenesis of mitochondria depends on the import of hundreds of preproteins. N-terminal matrix-targeting signals (MTSs) direct preproteins to the surface receptors Tom20, Tom22, and Tom70. In this study, we show that many preproteins contain additional internal MTS-like signals (iMTS-Ls) in their mature region that share the characteristic properties of presequences. These features allow the in silico prediction of iMTS-Ls. Using Atp1 as model substrate, we show that iMTS-Ls mediate the binding to Tom70 and have the potential to target the protein to mitochondria if they are presented at its N terminus. The import of preproteins with high iMTS-L content is significantly impaired in the absence of Tom70, whereas preproteins with low iMTS-L scores are less dependent on Tom70. We propose a stepping stone model according to which the Tom70-mediated interaction with internal binding sites improves the import competence of preproteins and increases the efficiency of their translocation into the mitochondrial matrix.
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Affiliation(s)
- Sandra Backes
- Cell Biology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Steffen Hess
- Cell Biology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Felix Boos
- Cell Biology, University of Kaiserslautern, Kaiserslautern, Germany
| | | | - Sabrina Gödel
- Computational Systems Biology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Martin Jung
- Medical Biochemistry, Saarland University, Homburg, Germany
| | - Timo Mühlhaus
- Computational Systems Biology, University of Kaiserslautern, Kaiserslautern, Germany
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8
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Xie JL, Bohovych I, Wong EOY, Lambert JP, Gingras AC, Khalimonchuk O, Cowen LE, Leach MD. Ydj1 governs fungal morphogenesis and stress response, and facilitates mitochondrial protein import via Mas1 and Mas2. MICROBIAL CELL 2017; 4:342-361. [PMID: 29082232 PMCID: PMC5657825 DOI: 10.15698/mic2017.10.594] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Mitochondria underpin metabolism, bioenergetics, signalling, development and cell death in eukaryotes. Most of the ~1,000 yeast mitochondrial proteins are encoded in the nucleus and synthesised as precursors in the cytosol, with mitochondrial import facilitated by molecular chaperones. Here, we focus on the Hsp40 chaperone Ydj1 in the fungal pathogen Candida albicans, finding that it is localised to both the cytosol and outer mitochondrial membrane, and is required for cellular stress responses and for filamentation, a key virulence trait. Mapping the Ydj1 protein interaction network highlighted connections with co-chaperones and regulators of filamentation. Furthermore, the mitochondrial processing peptidases Mas1 and Mas2 were highly enriched for interaction with Ydj1. Additional analysis demonstrated that loss of MAS1, MAS2 or YDJ1 perturbs mitochondrial morphology and function. Deletion of YDJ1 impairs import of Su9, a protein that is cleaved to a mature form by Mas1 and Mas2. Thus, we highlight a novel role for Ydj1 in cellular morphogenesis, stress responses, and mitochondrial import in the fungal kingdom.
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Affiliation(s)
- Jinglin L Xie
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Iryna Bohovych
- Department of Biochemistry, University of Nebraska, Lincoln, NE 68588, USA
| | - Erin O Y Wong
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Jean-Philippe Lambert
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, 600 University Avenue, Toronto, ON, M5G 1X5, Canada
| | - Anne-Claude Gingras
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.,Lunenfeld-Tanenbaum Research Institute, Sinai Health System, 600 University Avenue, Toronto, ON, M5G 1X5, Canada
| | - Oleh Khalimonchuk
- Department of Biochemistry, University of Nebraska, Lincoln, NE 68588, USA.,Nebraska Redox Biology Center, University of Nebraska, Lincoln, NE 68588, USA.,Fred & Pamela Buffett Cancer Center, Omaha, NE 68198, USA
| | - Leah E Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Michelle D Leach
- Aberdeen Fungal Group, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen, AB25 2ZD, UK.,Department of Molecular Genetics, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
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9
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Taylor NG, Swenson S, Harris NJ, Germany EM, Fox JL, Khalimonchuk O. The Assembly Factor Pet117 Couples Heme a Synthase Activity to Cytochrome Oxidase Assembly. J Biol Chem 2016; 292:1815-1825. [PMID: 27998984 DOI: 10.1074/jbc.m116.766980] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 12/13/2016] [Indexed: 11/06/2022] Open
Abstract
Heme a is an essential metalloporphyrin cofactor of the mitochondrial respiratory enzyme cytochrome c oxidase (CcO). Its synthesis from heme b requires several enzymes, including the evolutionarily conserved heme a synthase (Cox15). Oligomerization of Cox15 appears to be important for the process of heme a biosynthesis and transfer to maturing CcO. However, the details of this process remain elusive, and the roles of any additional CcO assembly factors that may be involved remain unclear. Here we report the systematic analysis of one such uncharacterized assembly factor, Pet117, and demonstrate in Saccharomyces cerevisiae that this evolutionarily conserved protein is necessary for Cox15 oligomerization and function. Pet117 is shown to reside in the mitochondrial matrix, where it is associated with the inner membrane. Pet117 functions at the later maturation stages of the core CcO subunit Cox1 that precede Cox1 hemylation. Pet117 also physically interacts with Cox15 and specifically mediates the stability of Cox15 oligomeric complexes. This Cox15-Pet117 interaction observed by co-immunoprecipitation persists in the absence of heme a synthase activity, is dependent upon Cox1 synthesis and early maturation steps, and is further dependent upon the presence of the matrix-exposed, unstructured linker region of Cox15 needed for Cox15 oligomerization, suggesting that this region mediates the interaction or that the interaction is lost when Cox15 is unable to oligomerize. Based on these findings, it was concluded that Pet117 mediates coupling of heme a synthesis to the CcO assembly process in eukaryotes.
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Affiliation(s)
- Nicholas G Taylor
- From the Department of Chemistry and Biochemistry, College of Charleston, Charleston, South Carolina 29424
| | - Samantha Swenson
- the Department of Biochemistry and Nebraska Redox Biology Center, University of Nebraska, Lincoln, Nebraska 68588
| | - Nicholas J Harris
- From the Department of Chemistry and Biochemistry, College of Charleston, Charleston, South Carolina 29424
| | - Edward M Germany
- the Department of Biochemistry and Nebraska Redox Biology Center, University of Nebraska, Lincoln, Nebraska 68588
| | - Jennifer L Fox
- From the Department of Chemistry and Biochemistry, College of Charleston, Charleston, South Carolina 29424.
| | - Oleh Khalimonchuk
- the Department of Biochemistry and Nebraska Redox Biology Center, University of Nebraska, Lincoln, Nebraska 68588.
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10
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Woellhaf MW, Sommer F, Schroda M, Herrmann JM. Proteomic profiling of the mitochondrial ribosome identifies Atp25 as a composite mitochondrial precursor protein. Mol Biol Cell 2016; 27:3031-3039. [PMID: 27582385 PMCID: PMC5063612 DOI: 10.1091/mbc.e16-07-0513] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 08/18/2016] [Accepted: 08/23/2016] [Indexed: 11/15/2022] Open
Abstract
Whereas the structure and function of cytosolic ribosomes are well characterized, we only have a limited understanding of the mitochondrial translation apparatus. Using SILAC-based proteomic profiling, we identified 13 proteins that cofractionated with the mitochondrial ribosome, most of which play a role in translation or ribosomal biogenesis. One of these proteins is a homologue of the bacterial ribosome-silencing factor (Rsf). This protein is generated from the composite precursor protein Atp25 upon internal cleavage by the matrix processing peptidase MPP, and in this respect, it differs from all other characterized mitochondrial proteins of baker's yeast. We observed that cytosolic expression of Rsf, but not of noncleaved Atp25 protein, is toxic. Our results suggest that eukaryotic cells face the challenge of avoiding negative interference from the biogenesis of their two distinct translation machineries.
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Affiliation(s)
- Michael W Woellhaf
- Cell Biology, University of Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Frederik Sommer
- Molecular Biotechnology and Systems Biology, University of Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Michael Schroda
- Molecular Biotechnology and Systems Biology, University of Kaiserslautern, 67663 Kaiserslautern, Germany
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11
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Angerer H. Eukaryotic LYR Proteins Interact with Mitochondrial Protein Complexes. BIOLOGY 2015; 4:133-50. [PMID: 25686363 PMCID: PMC4381221 DOI: 10.3390/biology4010133] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 02/04/2015] [Indexed: 01/18/2023]
Abstract
In eukaryotic cells, mitochondria host ancient essential bioenergetic and biosynthetic pathways. LYR (leucine/tyrosine/arginine) motif proteins (LYRMs) of the Complex1_LYR-like superfamily interact with protein complexes of bacterial origin. Many LYR proteins function as extra subunits (LYRM3 and LYRM6) or novel assembly factors (LYRM7, LYRM8, ACN9 and FMC1) of the oxidative phosphorylation (OXPHOS) core complexes. Structural insights into complex I accessory subunits LYRM6 and LYRM3 have been provided by analyses of EM and X-ray structures of complex I from bovine and the yeast Yarrowia lipolytica, respectively. Combined structural and biochemical studies revealed that LYRM6 resides at the matrix arm close to the ubiquinone reduction site. For LYRM3, a position at the distal proton-pumping membrane arm facing the matrix space is suggested. Both LYRMs are supposed to anchor an acyl-carrier protein (ACPM) independently to complex I. The function of this duplicated protein interaction of ACPM with respiratory complex I is still unknown. Analysis of protein-protein interaction screens, genetic analyses and predicted multi-domain LYRMs offer further clues on an interaction network and adaptor-like function of LYR proteins in mitochondria.
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Affiliation(s)
- Heike Angerer
- Goethe University Frankfurt, Medical School, Institute of Biochemistry II, Structural Bioenergetics Group, Max-von-Laue Street 9, Frankfurt am Main 60438, Germany.
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12
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Murai M, Matsunobu K, Kudo S, Ifuku K, Kawamukai M, Miyoshi H. Identification of the Binding Site of the Quinone-Head Group in Mitochondrial Coq10 by Photoaffinity Labeling. Biochemistry 2014; 53:3995-4003. [DOI: 10.1021/bi500347s] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | | | - Makoto Kawamukai
- Faculty of Life and Environmental
Science, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Japan
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13
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Molero C, Petrényi K, González A, Carmona M, Gelis S, Abrie JA, Strauss E, Ramos J, Dombradi V, Hidalgo E, Ariño J. The Schizosaccharomyces pombe fusion gene hal3 encodes three distinct activities. Mol Microbiol 2013; 90:367-82. [PMID: 23962284 DOI: 10.1111/mmi.12370] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2013] [Indexed: 11/30/2022]
Abstract
Saccharomyces cerevisiae Hal3 and Vhs3 are moonlighting proteins, forming an atypical heterotrimeric decarboxylase (PPCDC) required for CoA biosynthesis, and regulating cation homeostasis by inhibition of the Ppz1 phosphatase. The Schizosaccharomyces pombe ORF SPAC15E1.04 (renamed as Sp hal3) encodes a protein whose amino-terminal half is similar to Sc Hal3 whereas its carboxyl-terminal half is related to thymidylate synthase (TS). We show that Sp Hal3 and/or its N-terminal domain retain the ability to bind to and modestly inhibit in vitro S. cerevisiae Ppz1 as well as its S. pombe homolog Pzh1, and also exhibit PPCDC activity in vitro and provide PPCDC function in vivo, indicating that Sp Hal3 is a monogenic PPCDC in fission yeast. Whereas the Sp Hal3 N-terminal domain partially mimics Sc Hal3 functions, the entire protein and its carboxyl-terminal domain rescue the S. cerevisiae cdc21 mutant, thus proving TS function. Additionally, we show that the 70 kDa Sp Hal3 protein is not proteolytically processed under diverse forms of stress and that, as predicted, Sp hal3 is an essential gene. Therefore, Sp hal3 represents a fusion event that joined three different functional activities in the same gene. The possible advantage derived from this surprising combination of essential proteins is discussed.
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Affiliation(s)
- Cristina Molero
- Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
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14
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Transcriptional and cellular responses to defective mitochondrial proteolysis in fission yeast. J Mol Biol 2011; 408:222-37. [PMID: 21354177 DOI: 10.1016/j.jmb.2011.02.044] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Revised: 02/12/2011] [Accepted: 02/17/2011] [Indexed: 11/20/2022]
Abstract
Lon and m-AAA are the principal, regulated proteases required for protein maturation and turnover in the mitochondrial matrix of diverse species. To understand their roles in fission yeast (Schizosaccharomyces pombe) mitochondria, we generated deletion strains lacking Lon and m-AAA, individually (Δlon1 and Δm-AAA) or together, Δlon1Δm-AAA (Δ/Δ). All three strains were viable but incapable of respiratory growth on a non-fermentable carbon source due to mitochondrial dysfunction. Confocal and electron microscopy revealed a decrease in membrane potential and ultrastructural changes in Δlon1, Δm-AAA and Δ/Δ mitochondria, consistent with a respiratory defect and aggregation of proteins in the mitochondrial matrix. To understand the global adaptations required for cell survival in the absence of Lon and m-AAA proteases, we compared genome-wide gene expression signatures of the deletion strains with the isogenic wild-type strain. Deletion of lon1 caused a distinctive transcriptional footprint of just 12 differentially expressed genes, 9 of which were up-regulated genes located on the proximal mitochondrial genome (mitochondrial DNA). In contrast, m-AAA deletion caused a much larger transcriptional response involving 268 almost exclusively nuclear genes. Genes ameliorating stress and iron assimilation were up-regulated, while diverse mitochondrial genes and other metabolic enzymes were down-regulated. The connection with iron dysregulation was further explored using biochemical, chemical and cellular assays. Although Δm-AAA and Δ/Δ contained more cellular iron than the wild-type strain, their transcriptomes strongly resembled a signature normally evoked by iron insufficiency or disrupted assembly of iron-sulfur clusters in mitochondria. Based on these findings, we posit that excess iron accumulation could contribute to the pathology of human neurodegenerative disorders arising from defects in m-AAA function.
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Watts T, Khalimonchuk O, Wolf RZ, Turk EM, Mohr G, Winge DR. Mne1 is a novel component of the mitochondrial splicing apparatus responsible for processing of a COX1 group I intron in yeast. J Biol Chem 2011; 286:10137-46. [PMID: 21257754 DOI: 10.1074/jbc.m110.205625] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Saccharomyces cerevisiae cells lacking Mne1 are deficient in intron splicing in the gene encoding the Cox1 subunit of cytochrome oxidase but contain wild-type levels of the bc(1) complex. Thus, Mne1 has no role in splicing of COB introns or expression of the COB gene. Northern experiments suggest that splicing of the COX1 aI5β intron is dependent on Mne1 in addition to the previously known Mrs1, Mss116, Pet54, and Suv3 factors. Processing of the aI5β intron is similarly impaired in mne1Δ and mrs1Δ cells and overexpression of Mrs1 partially restores the respiratory function of mne1Δ cells. Mrs1 is known to function in the initial transesterification reaction of splicing. Mne1 is a mitochondrial matrix protein loosely associated with the inner membrane and is found in a high mass ribonucleoprotein complex specifically associated with the COX1 mRNA even within an intronless strain. Mne1 does not appear to have a secondary function in COX1 processing or translation, because disruption of MNE1 in cells containing intronless mtDNA does not lead to a respiratory growth defect. Thus, the primary defect in mne1Δ cells is splicing of the aI5β intron in COX1.
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Affiliation(s)
- Talina Watts
- Department of Medicine, University of Utah Health Sciences Center, Salt Lake City, Utah 84132, USA
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Khalimonchuk O, Bird A, Winge DR. Evidence for a pro-oxidant intermediate in the assembly of cytochrome oxidase. J Biol Chem 2007; 282:17442-9. [PMID: 17430883 DOI: 10.1074/jbc.m702379200] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The hydrogen peroxide sensitivity of cells lacking two proteins, Sco1 and Cox11, important in the assembly of cytochrome c oxidase (CcO), is shown to arise from the transient accumulation of a pro-oxidant heme A-Cox1 stalled intermediate. The peroxide sensitivity of these cells is abrogated by a reduction in either Cox1 expression or heme A formation but exacerbated by either enhanced Cox1 expression or heme A production arising from overexpression of COX15. Sco1 and Cox11 are implicated in the formation of the Cu(A) and Cu(B) sites of CcO, respectively. The respective wild-type genes suppress the peroxide sensitivities of sco1Delta and cox11Delta cells, but no cross-complementation is seen with noncognate genes. Copper-binding mutant alleles of Sco1 and Cox11 that are nonfunctional in promoting the assembly of CcO are functional in suppressing the peroxide sensitivity of their respective null mutants. Likewise, human Sco1 that is nonfunctional in yeast CcO assembly is able to suppress the peroxide sensitivity of yeast sco1Delta cells. Thus, a disconnect exists between the respiratory capacity of cells and hydrogen peroxide sensitivity. Hydrogen peroxide sensitivity of sco1Delta and cox11Delta cells is abrogated by overexpression of a novel mitochondrial ATPase Afg1 that promotes the degradation of CcO mitochondrially encoded subunits. Studies on the hydrogen peroxide sensitivity in CcO assembly mutants reveal new aspects of the CcO assembly process.
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Affiliation(s)
- Oleh Khalimonchuk
- University of Utah Health Sciences Center, Department of Medicine, Salt Lake City, Utah 84132, USA
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Current awareness on yeast. Yeast 2007. [DOI: 10.1002/yea.1324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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