1
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Carlström A, Ott M. Insights into conformational changes in cytochrome b during the early steps of its maturation. FEBS Lett 2024; 598:1438-1448. [PMID: 38664235 DOI: 10.1002/1873-3468.14888] [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: 12/12/2023] [Revised: 03/18/2024] [Accepted: 04/03/2024] [Indexed: 06/12/2024]
Abstract
Membrane proteins carrying redox cofactors are key subunits of respiratory chain complexes, yet the exact path of their folding and maturation remains poorly understood. Here, using cryo-EM and structure prediction via Alphafold2, we generated models of early assembly intermediates of cytochrome b (Cytb), a central subunit of complex III. The predicted structure of the first assembly intermediate suggests how the binding of Cytb to the assembly factor Cbp3-Cbp6 imposes an open configuration to facilitate the acquisition of its heme cofactors. Moreover, structure predictions of the second intermediate indicate how hemes get stabilized by binding of the assembly factor Cbp4, with a concomitant weakening of the contact between Cbp3-Cbp6 and Cytb, preparing for the release of the fully hemylated protein from the assembly factors.
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Affiliation(s)
- Andreas Carlström
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Sweden
| | - Martin Ott
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Sweden
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2
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Antolínez-Fernández Á, Esteban-Ramos P, Fernández-Moreno MÁ, Clemente P. Molecular pathways in mitochondrial disorders due to a defective mitochondrial protein synthesis. Front Cell Dev Biol 2024; 12:1410245. [PMID: 38855161 PMCID: PMC11157125 DOI: 10.3389/fcell.2024.1410245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 05/09/2024] [Indexed: 06/11/2024] Open
Abstract
Mitochondria play a central role in cellular metabolism producing the necessary ATP through oxidative phosphorylation. As a remnant of their prokaryotic past, mitochondria contain their own genome, which encodes 13 subunits of the oxidative phosphorylation system, as well as the tRNAs and rRNAs necessary for their translation in the organelle. Mitochondrial protein synthesis depends on the import of a vast array of nuclear-encoded proteins including the mitochondrial ribosome protein components, translation factors, aminoacyl-tRNA synthetases or assembly factors among others. Cryo-EM studies have improved our understanding of the composition of the mitochondrial ribosome and the factors required for mitochondrial protein synthesis and the advances in next-generation sequencing techniques have allowed for the identification of a growing number of genes involved in mitochondrial pathologies with a defective translation. These disorders are often multisystemic, affecting those tissues with a higher energy demand, and often present with neurodegenerative phenotypes. In this article, we review the known proteins required for mitochondrial translation, the disorders that derive from a defective mitochondrial protein synthesis and the animal models that have been established for their study.
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Affiliation(s)
- Álvaro Antolínez-Fernández
- Instituto de Investigaciones Biomédicas Sols-Morreale (IIBM), Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid, Spain
- Departamento de Bioquímica, Universidad Autónoma de Madrid, Madrid, Spain
| | - Paula Esteban-Ramos
- Instituto de Investigaciones Biomédicas Sols-Morreale (IIBM), Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid, Spain
- Departamento de Bioquímica, Universidad Autónoma de Madrid, Madrid, Spain
| | - Miguel Ángel Fernández-Moreno
- Instituto de Investigaciones Biomédicas Sols-Morreale (IIBM), Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid, Spain
- Departamento de Bioquímica, Universidad Autónoma de Madrid, Madrid, Spain
| | - Paula Clemente
- Instituto de Investigaciones Biomédicas Sols-Morreale (IIBM), Universidad Autónoma de Madrid-Consejo Superior de Investigaciones Científicas, Madrid, Spain
- Departamento de Bioquímica, Universidad Autónoma de Madrid, Madrid, Spain
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3
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Singh J, Singh S, Emam EAF, Varshney U. Role of Rmd9p in 3'-end processing of mitochondrial 15S rRNA in Saccharomyces cerevisiae. Mitochondrion 2024; 76:101876. [PMID: 38599301 DOI: 10.1016/j.mito.2024.101876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 02/05/2024] [Accepted: 04/07/2024] [Indexed: 04/12/2024]
Abstract
Ribosome biogenesis, involving processing/assembly of rRNAs and r-proteins is a vital process. In Saccharomyces cerevisiae mitochondria, ribosomal small subunit comprises 15S rRNA (15S). While the 15S 5'-end processing uses Ccm1p and Pet127p, the mechanisms of the 3'-end processing remain unclear. We reveal involvement of Rmd9p in safeguarding/processing 15S 3'-end. Rmd9p deficiency results in a cleavage at a position 183 nucleotides upstream of 15S 3'-end, and in the loss of the 3'-minor domain. Rmd9p binds to the sequences in the 3'-end region of 15S, and a genetic interaction between rmd9 and dss1 indicates that Rmd9p regulates/limits mtEXO activity during the 3'-end spacer processing.
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Affiliation(s)
- Jitendra Singh
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
| | - Sudhir Singh
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
| | - Elhassan Ali Fathi Emam
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
| | - Umesh Varshney
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India; Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India.
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4
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Jung SJ, Sridhara S, Ott M. Early steps in the biogenesis of mitochondrially encoded oxidative phosphorylation subunits. IUBMB Life 2024; 76:125-139. [PMID: 37712772 DOI: 10.1002/iub.2784] [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: 06/19/2023] [Accepted: 08/10/2023] [Indexed: 09/16/2023]
Abstract
The complexes mediating oxidative phosphorylation (OXPHOS) in the inner mitochondrial membrane consist of proteins encoded in the nuclear or the mitochondrial DNA. The mitochondrially encoded membrane proteins (mito-MPs) represent the catalytic core of these complexes and follow complicated pathways for biogenesis. Owing to their overall hydrophobicity, mito-MPs are co-translationally inserted into the inner membrane by the Oxa1 insertase. After insertion, OXPHOS biogenesis factors mediate the assembly of mito-MPs into complexes and participate in the regulation of mitochondrial translation, while protein quality control factors recognize and degrade faulty or excess proteins. This review summarizes the current understanding of these early steps occurring during the assembly of mito-MPs by concentrating on results obtained in the model organism baker's yeast.
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Affiliation(s)
- Sung-Jun Jung
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Sagar Sridhara
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Martin Ott
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
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5
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Sanyal S, Kouznetsova A, Ström L, Björkegren C. A system for inducible mitochondria-specific protein degradation in vivo. Nat Commun 2024; 15:1454. [PMID: 38365818 PMCID: PMC10873288 DOI: 10.1038/s41467-024-45819-6] [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: 02/24/2023] [Accepted: 02/05/2024] [Indexed: 02/18/2024] Open
Abstract
Targeted protein degradation systems developed for eukaryotes employ cytoplasmic machineries to perform proteolysis. This has prevented mitochondria-specific analysis of proteins that localize to multiple locations, for example, the mitochondria and the nucleus. Here, we present an inducible mitochondria-specific protein degradation system in Saccharomyces cerevisiae based on the Mesoplasma florum Lon (mf-Lon) protease and its corresponding ssrA tag (called PDT). We show that mitochondrially targeted mf-Lon protease efficiently and selectively degrades a PDT-tagged reporter protein localized to the mitochondrial matrix. The degradation can be induced by depleting adenine from the medium, and tuned by altering the promoter strength of the MF-LON gene. We furthermore demonstrate that mf-Lon specifically degrades endogenous, PDT-tagged mitochondrial proteins. Finally, we show that mf-Lon-dependent PDT degradation can also be achieved in human mitochondria. In summary, this system provides an efficient tool to selectively analyze the mitochondrial function of dually localized proteins.
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Affiliation(s)
- Swastika Sanyal
- Karolinska Institutet, Department of Biosciences and Nutrition, Neo, Hälsovägen 7c, 141 83, Huddinge, Sweden.
| | - Anna Kouznetsova
- Karolinska Institutet, Department of Cell and Molecular Biology, Biomedicum, Tomtebodavägen 16, 171 77, Stockholm, Sweden
| | - Lena Ström
- Karolinska Institutet, Department of Cell and Molecular Biology, Biomedicum, Tomtebodavägen 16, 171 77, Stockholm, Sweden
| | - Camilla Björkegren
- Karolinska Institutet, Department of Cell and Molecular Biology, Biomedicum, Tomtebodavägen 16, 171 77, Stockholm, Sweden.
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6
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Kohler V, Kohler A, Berglund LL, Hao X, Gersing S, Imhof A, Nyström T, Höög JL, Ott M, Andréasson C, Büttner S. Nuclear Hsp104 safeguards the dormant translation machinery during quiescence. Nat Commun 2024; 15:315. [PMID: 38182580 PMCID: PMC10770042 DOI: 10.1038/s41467-023-44538-8] [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: 06/01/2023] [Accepted: 12/15/2023] [Indexed: 01/07/2024] Open
Abstract
The resilience of cellular proteostasis declines with age, which drives protein aggregation and compromises viability. The nucleus has emerged as a key quality control compartment that handles misfolded proteins produced by the cytosolic protein biosynthesis system. Here, we find that age-associated metabolic cues target the yeast protein disaggregase Hsp104 to the nucleus to maintain a functional nuclear proteome during quiescence. The switch to respiratory metabolism and the accompanying decrease in translation rates direct cytosolic Hsp104 to the nucleus to interact with latent translation initiation factor eIF2 and to suppress protein aggregation. Hindering Hsp104 from entering the nucleus in quiescent cells results in delayed re-entry into the cell cycle due to compromised resumption of protein synthesis. In sum, we report that cytosolic-nuclear partitioning of the Hsp104 disaggregase is a critical mechanism to protect the latent protein synthesis machinery during quiescence in yeast, ensuring the rapid restart of translation once nutrients are replenished.
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Affiliation(s)
- Verena Kohler
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691, Stockholm, Sweden
- Institute of Molecular Biosciences, University of Graz, 8010, Graz, Austria
- Department of Molecular Biology, Umeå University, 90187, Umeå, Sweden
| | - Andreas Kohler
- Institute of Molecular Biosciences, University of Graz, 8010, Graz, Austria
- Department of Biochemistry and Biophysics, Stockholm University, 10691, Stockholm, Sweden
- Department of Medical Biochemistry and Biophysics, Umeå University, 90187, Umeå, Sweden
| | - Lisa Larsson Berglund
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530, Gothenburg, Sweden
| | - Xinxin Hao
- Department of Microbiology and Immunology, University of Gothenburg, 40530, Gothenburg, Sweden
| | - Sarah Gersing
- The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, 1165, Copenhagen, Denmark
| | - Axel Imhof
- Biomedical Center Munich, Faculty of Medicine, Ludwig Maximilian University of Munich, 82152, Planegg-Martinsried, Germany
| | - Thomas Nyström
- Department of Microbiology and Immunology, University of Gothenburg, 40530, Gothenburg, Sweden
| | - Johanna L Höög
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530, Gothenburg, Sweden
| | - Martin Ott
- Department of Biochemistry and Biophysics, Stockholm University, 10691, Stockholm, Sweden
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, 40530, Gothenburg, Sweden
| | - Claes Andréasson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691, Stockholm, Sweden.
| | - Sabrina Büttner
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691, Stockholm, Sweden.
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7
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Kohler A, Barrientos A, Fontanesi F, Ott M. The functional significance of mitochondrial respiratory chain supercomplexes. EMBO Rep 2023; 24:e57092. [PMID: 37828827 PMCID: PMC10626428 DOI: 10.15252/embr.202357092] [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] [Received: 02/28/2023] [Revised: 07/10/2023] [Accepted: 09/14/2023] [Indexed: 10/14/2023] Open
Abstract
The mitochondrial respiratory chain (MRC) is a key energy transducer in eukaryotic cells. Four respiratory chain complexes cooperate in the transfer of electrons derived from various metabolic pathways to molecular oxygen, thereby establishing an electrochemical gradient over the inner mitochondrial membrane that powers ATP synthesis. This electron transport relies on mobile electron carries that functionally connect the complexes. While the individual complexes can operate independently, they are in situ organized into large assemblies termed respiratory supercomplexes. Recent structural and functional studies have provided some answers to the question of whether the supercomplex organization confers an advantage for cellular energy conversion. However, the jury is still out, regarding the universality of these claims. In this review, we discuss the current knowledge on the functional significance of MRC supercomplexes, highlight experimental limitations, and suggest potential new strategies to overcome these obstacles.
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Affiliation(s)
- Andreas Kohler
- Department of Biochemistry and BiophysicsStockholm UniversityStockholmSweden
- Institute of Molecular BiosciencesUniversity of GrazGrazAustria
| | - Antoni Barrientos
- Department of Neurology, Miller School of MedicineUniversity of MiamiMiamiFLUSA
- Department of Biochemistry and Molecular Biology, Miller School of MedicineUniversity of MiamiMiamiFLUSA
| | - Flavia Fontanesi
- Department of Biochemistry and Molecular Biology, Miller School of MedicineUniversity of MiamiMiamiFLUSA
| | - Martin Ott
- Department of Biochemistry and BiophysicsStockholm UniversityStockholmSweden
- Department of Medical Biochemistry and Cell BiologyUniversity of GothenburgGothenburgSweden
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8
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Nieto-Panqueva F, Rubalcava-Gracia D, Hamel PP, González-Halphen D. The constraints of allotopic expression. Mitochondrion 2023; 73:30-50. [PMID: 37739243 DOI: 10.1016/j.mito.2023.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 08/28/2023] [Accepted: 09/18/2023] [Indexed: 09/24/2023]
Abstract
Allotopic expression is the functional transfer of an organellar gene to the nucleus, followed by synthesis of the gene product in the cytosol and import into the appropriate organellar sub compartment. Here, we focus on mitochondrial genes encoding OXPHOS subunits that were naturally transferred to the nucleus, and critically review experimental evidence that claim their allotopic expression. We emphasize aspects that may have been overlooked before, i.e., when modifying a mitochondrial gene for allotopic expression━besides adapting the codon usage and including sequences encoding mitochondrial targeting signals━three additional constraints should be considered: (i) the average apparent free energy of membrane insertion (μΔGapp) of the transmembrane stretches (TMS) in proteins earmarked for the inner mitochondrial membrane, (ii) the final, functional topology attained by each membrane-bound OXPHOS subunit; and (iii) the defined mechanism by which the protein translocator TIM23 sorts cytosol-synthesized precursors. The mechanistic constraints imposed by TIM23 dictate the operation of two pathways through which alpha-helices in TMS are sorted, that eventually determine the final topology of membrane proteins. We used the biological hydrophobicity scale to assign an average apparent free energy of membrane insertion (μΔGapp) and a "traffic light" color code to all TMS of OXPHOS membrane proteins, thereby predicting which are more likely to be internalized into mitochondria if allotopically produced. We propose that the design of proteins for allotopic expression must make allowance for μΔGapp maximization of highly hydrophobic TMS in polypeptides whose corresponding genes have not been transferred to the nucleus in some organisms.
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Affiliation(s)
- Felipe Nieto-Panqueva
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Diana Rubalcava-Gracia
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico; Division of Molecular Metabolism, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Patrice P Hamel
- Department of Molecular Genetics and Department of Biological Chemistry and Pharmacology, Ohio State University, Columbus, OH, USA; Vellore Institute of Technology (VIT), School of BioScience and Technology, Vellore, Tamil Nadu, India
| | - Diego González-Halphen
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico.
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9
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Potter A, Cabrera-Orefice A, Spelbrink JN. Let's make it clear: systematic exploration of mitochondrial DNA- and RNA-protein complexes by complexome profiling. Nucleic Acids Res 2023; 51:10619-10641. [PMID: 37615582 PMCID: PMC10602928 DOI: 10.1093/nar/gkad697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 07/18/2023] [Accepted: 08/11/2023] [Indexed: 08/25/2023] Open
Abstract
Complexome profiling (CP) is a powerful tool for systematic investigation of protein interactors that has been primarily applied to study the composition and dynamics of mitochondrial protein complexes. Here, we further optimized this method to extend its application to survey mitochondrial DNA- and RNA-interacting protein complexes. We established that high-resolution clear native gel electrophoresis (hrCNE) is a better alternative to preserve DNA- and RNA-protein interactions that are otherwise disrupted when samples are separated by the widely used blue native gel electrophoresis (BNE). In combination with enzymatic digestion of DNA, our CP approach improved the identification of a wide range of protein interactors of the mitochondrial gene expression system without compromising the detection of other multiprotein complexes. The utility of this approach was particularly demonstrated by analysing the complexome changes in human mitochondria with impaired gene expression after transient, chemically induced mitochondrial DNA depletion. Effects of RNase on mitochondrial protein complexes were also evaluated and discussed. Overall, our adaptations significantly improved the identification of mitochondrial DNA- and RNA-protein interactions by CP, thereby unlocking the comprehensive analysis of a near-complete mitochondrial complexome in a single experiment.
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Affiliation(s)
- Alisa Potter
- Department of Pediatrics, Amalia Children's Hospital, Radboud University Medical Center, Nijmegen, The Netherlands
- Radboud Center for Mitochondrial Medicine (RCMM), Radboud University Medical Center, Nijmegen, The Netherlands
| | - Alfredo Cabrera-Orefice
- Radboud Center for Mitochondrial Medicine (RCMM), Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Medical BioSciences, Radboud University Medical Center, Nijmegen, The Netherlands
- Functional Proteomics, Institute for Cardiovascular Physiology, Goethe University, Frankfurt am Main, Germany
| | - Johannes N Spelbrink
- Department of Pediatrics, Amalia Children's Hospital, Radboud University Medical Center, Nijmegen, The Netherlands
- Radboud Center for Mitochondrial Medicine (RCMM), Radboud University Medical Center, Nijmegen, The Netherlands
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10
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Kohler A, Carlström A, Nolte H, Kohler V, Jung SJ, Sridhara S, Tatsuta T, Berndtsson J, Langer T, Ott M. Early fate decision for mitochondrially encoded proteins by a molecular triage. Mol Cell 2023; 83:3470-3484.e8. [PMID: 37751741 DOI: 10.1016/j.molcel.2023.09.001] [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: 02/13/2023] [Revised: 07/12/2023] [Accepted: 09/05/2023] [Indexed: 09/28/2023]
Abstract
Folding of newly synthesized proteins poses challenges for a functional proteome. Dedicated protein quality control (PQC) systems either promote the folding of nascent polypeptides at ribosomes or, if this fails, ensure their degradation. Although well studied for cytosolic protein biogenesis, it is not understood how these processes work for mitochondrially encoded proteins, key subunits of the oxidative phosphorylation (OXPHOS) system. Here, we identify dedicated hubs in proximity to mitoribosomal tunnel exits coordinating mitochondrial protein biogenesis and quality control. Conserved prohibitin (PHB)/m-AAA protease supercomplexes and the availability of assembly chaperones determine the fate of newly synthesized proteins by molecular triaging. The localization of these competing activities in the vicinity of the mitoribosomal tunnel exit allows for a prompt decision on whether newly synthesized proteins are fed into OXPHOS assembly or are degraded.
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Affiliation(s)
- Andreas Kohler
- Department of Biochemistry and Biophysics, Stockholm University, 106 91 Stockholm, Sweden; Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Andreas Carlström
- Department of Biochemistry and Biophysics, Stockholm University, 106 91 Stockholm, Sweden
| | - Hendrik Nolte
- Max Planck Institute for Biology of Ageing, 50931 Cologne, Germany
| | - Verena Kohler
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 106 91 Stockholm, Sweden
| | - Sung-Jun Jung
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Sagar Sridhara
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Takashi Tatsuta
- Max Planck Institute for Biology of Ageing, 50931 Cologne, Germany
| | - Jens Berndtsson
- Department of Biochemistry and Biophysics, Stockholm University, 106 91 Stockholm, Sweden
| | - Thomas Langer
- Max Planck Institute for Biology of Ageing, 50931 Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany.
| | - Martin Ott
- Department of Biochemistry and Biophysics, Stockholm University, 106 91 Stockholm, Sweden; Department of Medical Biochemistry and Cell Biology, University of Gothenburg, 405 30 Gothenburg, Sweden.
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11
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Homberg B, Rehling P, Cruz-Zaragoza LD. The multifaceted mitochondrial OXA insertase. Trends Cell Biol 2023; 33:765-772. [PMID: 36863885 DOI: 10.1016/j.tcb.2023.02.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 02/02/2023] [Accepted: 02/03/2023] [Indexed: 03/04/2023]
Abstract
Most mitochondrial proteins are synthesized in the cytosol and transported into mitochondria by protein translocases. Yet, mitochondria contain their own genome and gene expression system, which generates proteins that are inserted in the inner membrane by the oxidase assembly (OXA) insertase. OXA contributes to targeting proteins from both genetic origins. Recent data provides insights into how OXA cooperates with the mitochondrial ribosome during synthesis of mitochondrial-encoded proteins. A picture of OXA emerges in which it coordinates insertion of OXPHOS core subunits and their assembly into protein complexes but also participates in the biogenesis of select imported proteins. These functions position the OXA as a multifunctional protein insertase that facilitates protein transport, assembly, and stability at the inner membrane.
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Affiliation(s)
- Bettina Homberg
- Department of Cellular Biochemistry, University Medical Center Göttingen, 37073 Göttingen, Germany
| | - Peter Rehling
- Department of Cellular Biochemistry, University Medical Center Göttingen, 37073 Göttingen, Germany; Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), 37073 University of Göttingen, Germany; Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Translational Neuroinflammation and Automated Microscopy TNM, 37075 Göttingen, Germany; Max Planck Institute for Multidisciplinary Science, 37077 Göttingen, Germany.
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12
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Sheng J, Li X, Lei J, Gan W, Song J. Mitochondrial quality control in acute kidney disease. J Nephrol 2023; 36:1283-1291. [PMID: 36800104 DOI: 10.1007/s40620-023-01582-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Accepted: 01/13/2023] [Indexed: 02/18/2023]
Abstract
Acute kidney disease (AKD) involves multiple pathogenic mechanisms, including maladaptive repair of renal cells that are rich in mitochondria. Maintenance of mitochondrial homeostasis and quality control is crucial for normal kidney function. Mitochondrial quality control serves to maintain mitochondrial function under various conditions, including mitochondrial bioenergetics, mitochondrial biogenesis, mitochondrial dynamics (fusion and fission) and mitophagy. To date, increasing evidence indicates that mitochondrial quality control is disrupted when acute kidney disease develops. This review describes the mechanisms of mitochondria quality control in acute kidney disease, aiming to provide clues to help design new clinical treatments.
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Affiliation(s)
- Jingyi Sheng
- Department of Pediatric Nephrology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, 210011, China
| | - Xian Li
- Department of Emergency, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Juan Lei
- Department of Pediatric Nephrology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, 210011, China
| | - WeiHua Gan
- Department of Pediatric Nephrology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, 210011, China
| | - Jiayu Song
- Department of Pediatric Nephrology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, 210011, China.
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13
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Chen M, Yan R, Luo J, Ning J, Zhou R, Ding L. The Role of PGC-1α-Mediated Mitochondrial Biogenesis in Neurons. Neurochem Res 2023:10.1007/s11064-023-03934-8. [PMID: 37097395 DOI: 10.1007/s11064-023-03934-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 03/28/2023] [Accepted: 03/31/2023] [Indexed: 04/26/2023]
Abstract
Neurons are highly dependent on mitochondrial ATP production and Ca2+ buffering. Neurons have unique compartmentalized anatomy and energy requirements, and each compartment requires continuously renewed mitochondria to maintain neuronal survival and activity. Peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) is a key factor in the regulation of mitochondrial biogenesis. It is widely accepted that mitochondria are synthesized in the cell body and transported via axons to the distal end. However, axonal mitochondrial biogenesis is necessary to maintain axonal bioenergy supply and mitochondrial density due to limitations in mitochondrial axonal transport rate and mitochondrial protein lifespan. In addition, impaired mitochondrial biogenesis leading to inadequate energy supply and neuronal damage has been observed in neurological disorders. In this review, we focus on the sites where mitochondrial biogenesis occurs in neurons and the mechanisms by which it maintains axonal mitochondrial density. Finally, we summarize several neurological disorders in which mitochondrial biogenesis is affected.
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Affiliation(s)
- Mengjie Chen
- Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing, 100010, China
| | - Ruyu Yan
- Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing, 100010, China
| | - Jiansheng Luo
- Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing, 100010, China
| | - Jiaqi Ning
- Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing, 100010, China
| | - Ruiling Zhou
- Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing, 100010, China
| | - Lingling Ding
- Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing, 100010, China.
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14
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Fenech EJ, Cohen N, Kupervaser M, Gazi Z, Schuldiner M. A toolbox for systematic discovery of stable and transient protein interactors in baker's yeast. Mol Syst Biol 2023; 19:e11084. [PMID: 36651308 PMCID: PMC9912024 DOI: 10.15252/msb.202211084] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 12/19/2022] [Accepted: 12/20/2022] [Indexed: 01/19/2023] Open
Abstract
Identification of both stable and transient interactions is essential for understanding protein function and regulation. While assessing stable interactions is more straightforward, capturing transient ones is challenging. In recent years, sophisticated tools have emerged to improve transient interactor discovery, with many harnessing the power of evolved biotin ligases for proximity labelling. However, biotinylation-based methods have lagged behind in the model eukaryote, Saccharomyces cerevisiae, possibly due to the presence of several abundant, endogenously biotinylated proteins. In this study, we optimised robust biotin-ligation methodologies in yeast and increased their sensitivity by creating a bespoke technique for downregulating endogenous biotinylation, which we term ABOLISH (Auxin-induced BiOtin LIgase diminiSHing). We used the endoplasmic reticulum insertase complex (EMC) to demonstrate our approaches and uncover new substrates. To make these tools available for systematic probing of both stable and transient interactions, we generated five full-genome collections of strains in which every yeast protein is tagged with each of the tested biotinylation machineries, some on the background of the ABOLISH system. This comprehensive toolkit enables functional interactomics of the entire yeast proteome.
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Affiliation(s)
- Emma J Fenech
- Department of Molecular GeneticsWeizmann Institute of ScienceRehovotIsrael
| | - Nir Cohen
- Department of Molecular GeneticsWeizmann Institute of ScienceRehovotIsrael
| | - Meital Kupervaser
- The de Botton Protein Profiling Institute of the Nancy and Stephen Grand Israel National Centre for Personalized MedicineWeizmann Institute of ScienceRehovotIsrael
| | - Zohar Gazi
- Department of Molecular GeneticsWeizmann Institute of ScienceRehovotIsrael
| | - Maya Schuldiner
- Department of Molecular GeneticsWeizmann Institute of ScienceRehovotIsrael
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15
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Hubble KA, Henry MF. DPC29 promotes post-initiation mitochondrial translation in Saccharomyces cerevisiae. Nucleic Acids Res 2023; 51:1260-1276. [PMID: 36620885 PMCID: PMC9943650 DOI: 10.1093/nar/gkac1229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 12/07/2022] [Accepted: 12/09/2022] [Indexed: 01/10/2023] Open
Abstract
Mitochondrial ribosomes synthesize essential components of the oxidative phosphorylation (OXPHOS) system in a tightly regulated process. In the yeast Saccharomyces cerevisiae, mitochondrial mRNAs require specific translational activators, which orchestrate protein synthesis by recognition of their target gene's 5'-untranslated region (UTR). Most of these yeast genes lack orthologues in mammals, and only one such gene-specific translational activator has been proposed in humans-TACO1. The mechanism by which TACO1 acts is unclear because mammalian mitochondrial mRNAs do not have significant 5'-UTRs, and therefore must promote translation by alternative mechanisms. In this study, we examined the role of the TACO1 orthologue in yeast. We found this 29 kDa protein to be a general mitochondrial translation factor, Dpc29, rather than a COX1-specific translational activator. Its activity was necessary for the optimal expression of OXPHOS mtDNA reporters, and mutations within the mitoribosomal large subunit protein gene MRP7 produced a global reduction of mitochondrial translation in dpc29Δ cells, indicative of a general mitochondrial translation factor. Northern-based mitoribosome profiling of dpc29Δ cells showed higher footprint frequencies at the 3' ends of mRNAs, suggesting a role in translation post-initiation. Additionally, human TACO1 expressed at native levels rescued defects in dpc29Δ yeast strains, suggesting that the two proteins perform highly conserved functions.
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Affiliation(s)
- Kyle A Hubble
- Department of Molecular Biology, Rowan University School of Osteopathic Medicine, Stratford, NJ 08084, USA,Graduate School of Biomedical Sciences, Rowan University, Stratford, NJ 08084, USA
| | - Michael F Henry
- To whom correspondence should be addressed. Tel: +1 856 566 6970; Fax: +1 856 566 6291; E-mail:
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16
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Aufschnaiter A, Carlström A, Ott M. Yeast Mitoribosome Purification and Analyses by Sucrose Density Centrifugation and Immunoprecipitation. Methods Mol Biol 2023; 2661:119-132. [PMID: 37166635 DOI: 10.1007/978-1-0716-3171-3_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Mitochondrial protein biosynthesis is maintained by an interplay between the mitochondrial ribosome (mitoribosome) and a large set of protein interaction partners. This interactome regulates a diverse set of functions, including mitochondrial gene expression, translation, protein quality control, and respiratory chain assembly. Hence, robust methods to biochemically and structurally analyze this molecular machinery are required to understand the sophisticated regulation of mitochondrial protein biosynthesis. In this chapter, we present detailed protocols for immunoprecipitation, sucrose cushions, and linear sucrose gradients to purify and analyze mitoribosomes and their interaction partners.
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Affiliation(s)
- Andreas Aufschnaiter
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Andreas Carlström
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Martin Ott
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg, Sweden.
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17
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Bertgen L, Flohr T, Herrmann JM. Methods to Study the Biogenesis of Mitoribosomal Proteins in Yeast. Methods Mol Biol 2023; 2661:143-161. [PMID: 37166637 DOI: 10.1007/978-1-0716-3171-3_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The biogenesis of mitoribosomes is an intricate process that relies on the coordinated synthesis of nuclear-encoded mitoribosomal proteins (MRPs) in the cytosol, their translocation across mitochondrial membranes, the transcription of rRNA molecules in the matrix as well as the assembly of the roughly 80 different constituents of the mitoribosome. Numerous chaperones, translocases, processing peptidases, and assembly factors of the cytosol and in mitochondria support this complex reaction. The budding yeast Saccharomyces cerevisiae served as a powerful model organism to unravel the different steps by which MRPs are imported into mitochondria, fold into their native structures, and assemble into functional ribosomes.In this chapter, we provide established protocols to study these different processes experimentally. In particular, we describe methods to purify mitochondria from yeast cells, to import radiolabeled MRPs into isolated mitochondria, and to elucidate the assembly reaction of MRPs by immunoprecipitation. These protocols and the list of dos and don'ts will enable beginners and experienced scientists to study the import and assembly of MRPs.
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Affiliation(s)
- Lea Bertgen
- Cell Biology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Tamara Flohr
- Cell Biology, University of Kaiserslautern, Kaiserslautern, Germany
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18
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Dickinson Q, Aufschnaiter A, Ott M, Meyer JG. Multi-omic integration by machine learning (MIMaL). Bioinformatics 2022; 38:4908-4918. [PMID: 36106996 PMCID: PMC9801967 DOI: 10.1093/bioinformatics/btac631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 08/17/2022] [Accepted: 09/14/2022] [Indexed: 01/05/2023] Open
Abstract
MOTIVATION Cells respond to environments by regulating gene expression to exploit resources optimally. Recent advances in technologies allow for measuring the abundances of RNA, proteins, lipids and metabolites. These highly complex datasets reflect the states of the different layers in a biological system. Multi-omics is the integration of these disparate methods and data to gain a clearer picture of the biological state. Multi-omic studies of the proteome and metabolome are becoming more common as mass spectrometry technology continues to be democratized. However, knowledge extraction through the integration of these data remains challenging. RESULTS Connections between molecules in different omic layers were discovered through a combination of machine learning and model interpretation. Discovered connections reflected protein control (ProC) over metabolites. Proteins discovered to control citrate were mapped onto known genetic and metabolic networks, revealing that these protein regulators are novel. Further, clustering the magnitudes of ProC over all metabolites enabled the prediction of five gene functions, each of which was validated experimentally. Two uncharacterized genes, YJR120W and YDL157C, were accurately predicted to modulate mitochondrial translation. Functions for three incompletely characterized genes were also predicted and validated, including SDH9, ISC1 and FMP52. A website enables results exploration and also MIMaL analysis of user-supplied multi-omic data. AVAILABILITY AND IMPLEMENTATION The website for MIMaL is at https://mimal.app. Code for the website is at https://github.com/qdickinson/mimal-website. Code to implement MIMaL is at https://github.com/jessegmeyerlab/MIMaL. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Quinn Dickinson
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Department of Computational Biomedicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Andreas Aufschnaiter
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Martin Ott
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Jesse G Meyer
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Department of Computational Biomedicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
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19
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Overexpression of MRX9 impairs processing of RNAs encoding mitochondrial oxidative phosphorylation factors COB and COX1 in yeast. J Biol Chem 2022; 298:102214. [PMID: 35779633 PMCID: PMC9307953 DOI: 10.1016/j.jbc.2022.102214] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 06/20/2022] [Accepted: 06/21/2022] [Indexed: 11/24/2022] Open
Abstract
Mitochondrial translation is a highly regulated process, and newly synthesized mitochondrial products must first associate with several nuclear-encoded auxiliary factors to form oxidative phosphorylation complexes. The output of mitochondrial products should therefore be in stoichiometric equilibrium with the nuclear-encoded products to prevent unnecessary energy expense or the accumulation of pro-oxidant assembly modules. In the mitochondrial DNA of Saccharomyces cerevisiae, COX1 encodes subunit 1 of the cytochrome c oxidase and COB the central core of the cytochrome bc1 electron transfer complex; however, factors regulating the expression of these mitochondrial products are not completely described. Here, we identified Mrx9p as a new factor that controls COX1 and COB expression. We isolated MRX9 in a screen for mitochondrial factors that cause poor accumulation of newly synthesized Cox1p and compromised transition to the respiratory metabolism. Northern analyses indicated lower levels of COX1 and COB mature mRNAs accompanied by an accumulation of unprocessed transcripts in the presence of excess Mrx9p. In a strain devoid of mitochondrial introns, MRX9 overexpression did not affect COX1 and COB translation or respiratory adaptation, implying Mrx9p regulates processing of COX1 and COB RNAs. In addition, we found Mrx9p was localized in the mitochondrial inner membrane, facing the matrix, as a portion of it cosedimented with mitoribosome subunits and its removal or overexpression altered Mss51p sedimentation. Finally, we showed accumulation of newly synthesized Cox1p in the absence of Mrx9p was diminished in cox14 null mutants. Taken together, these data indicate a regulatory role of Mrx9p in COX1 RNA processing.
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20
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Coordination of metal center biogenesis in human cytochrome c oxidase. Nat Commun 2022; 13:3615. [PMID: 35750769 PMCID: PMC9232578 DOI: 10.1038/s41467-022-31413-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 06/16/2022] [Indexed: 01/12/2023] Open
Abstract
Mitochondrial cytochrome c oxidase (CcO) or respiratory chain complex IV is a heme aa3-copper oxygen reductase containing metal centers essential for holo-complex biogenesis and enzymatic function that are assembled by subunit-specific metallochaperones. The enzyme has two copper sites located in the catalytic core subunits. The COX1 subunit harbors the CuB site that tightly associates with heme a3 while the COX2 subunit contains the binuclear CuA site. Here, we report that in human cells the CcO copper chaperones form macromolecular assemblies and cooperate with several twin CX9C proteins to control heme a biosynthesis and coordinate copper transfer sequentially to the CuA and CuB sites. These data on CcO illustrate a mechanism that regulates the biogenesis of macromolecular enzymatic assemblies with several catalytic metal redox centers and prevents the accumulation of cytotoxic reactive assembly intermediates.
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21
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Chojnacka KJ, Elancheliyan P, Mussulini BHM, Mohanraj K, Callegari S, Gosk A, Banach T, Góral T, Szczepanowska K, Rehling P, Serwa RA, Chacińska A. Ovarian carcinoma immunoreactive antigen-like protein 2 (OCIAD2) is a novel complex III specific assembly factor in mitochondria. Mol Biol Cell 2022; 33:ar29. [PMID: 35080992 PMCID: PMC9250361 DOI: 10.1091/mbc.e21-03-0143] [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] [Indexed: 11/11/2022] Open
Abstract
Assembly of the dimeric complex III (CIII2) in the mitochondrial inner membrane is an intricate process in which several accessory proteins are involved as assembly factors. Despite numerous studies, this process has yet to be fully understood. Here we report the identification of human OCIAD2 (ovarian carcinoma immunoreactive antigen–like protein 2) as an assembly factor for CIII2. OCIAD2 was found to be deregulated in several carcinomas and also in some neurogenerative disorders; however, its nonpathological role had not been elucidated. We have shown that OCIAD2 localizes to mitochondria and interacts with electron transport chain (ETC) proteins. Complete loss of OCIAD2 using gene editing in HEK293 cells resulted in abnormal mitochondrial morphology, a substantial decrease of both CIII2 and supercomplex III2+IV, and a reduction in CIII enzymatic activity. Identification of OCIAD2 as a protein required for assembly of functional CIII2 provides a new insight into the biogenesis and architecture of the ETC. Elucidating the mechanism of OCIAD2 action is important both for the understanding of cellular metabolism and for an understanding of its role in malignant transformation.
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Affiliation(s)
| | | | | | - Karthik Mohanraj
- ReMedy International Research Agenda Unit, IMol Polish Academy of Sciences, Warsaw, Poland
| | - Sylvie Callegari
- Ubiquitin Signalling Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Cellular Biochemistry, University Medical Center Göttingen, 37073, Göttingen, Germany
| | - Aleksandra Gosk
- Centre of New Technologies, University of Warsaw, 02-097 Warsaw, Poland
| | - Tomasz Banach
- ReMedy International Research Agenda Unit, IMol Polish Academy of Sciences, Warsaw, Poland
| | - Tomasz Góral
- Centre of New Technologies, University of Warsaw, 02-097 Warsaw, Poland
| | - Karolina Szczepanowska
- ReMedy International Research Agenda Unit, IMol Polish Academy of Sciences, Warsaw, Poland
| | - Peter Rehling
- Department of Cellular Biochemistry, University Medical Center Göttingen, 37073, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Goettingen, Germany.,Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Remigiusz Adam Serwa
- ReMedy International Research Agenda Unit, IMol Polish Academy of Sciences, Warsaw, Poland
| | - Agnieszka Chacińska
- ReMedy International Research Agenda Unit, IMol Polish Academy of Sciences, Warsaw, Poland
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22
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Schell R, Hale JJ, Mullis MN, Matsui T, Foree R, Ehrenreich IM. Genetic basis of a spontaneous mutation’s expressivity. Genetics 2022; 220:6515283. [PMID: 35078232 PMCID: PMC8893249 DOI: 10.1093/genetics/iyac013] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 01/19/2022] [Indexed: 11/12/2022] Open
Abstract
Abstract
Genetic background often influences the phenotypic consequences of mutations, resulting in variable expressivity. How standing genetic variants collectively cause this phenomenon is not fully understood. Here, we comprehensively identify loci in a budding yeast cross that impact the growth of individuals carrying a spontaneous missense mutation in the nuclear-encoded mitochondrial ribosomal gene MRP20. Initial results suggested that a single large effect locus influences the mutation’s expressivity, with one allele causing inviability in mutants. However, further experiments revealed this simplicity was an illusion. In fact, many additional loci shape the mutation’s expressivity, collectively leading to a wide spectrum of mutational responses. These results exemplify how complex combinations of alleles can produce a diversity of qualitative and quantitative responses to the same mutation.
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Affiliation(s)
- Rachel Schell
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Joseph J Hale
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Martin N Mullis
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Takeshi Matsui
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Ryan Foree
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Ian M Ehrenreich
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
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23
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Hijazi I, Wang E, Orozco M, Pelton S, Chang A. Peroxisomal support of mitochondrial respiratory efficiency promotes ER stress survival. J Cell Sci 2022; 135:273605. [PMID: 34854901 PMCID: PMC8767275 DOI: 10.1242/jcs.259254] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 11/18/2021] [Indexed: 01/12/2023] Open
Abstract
Endoplasmic reticulum stress (ERS) occurs when cellular demand for protein folding exceeds the capacity of the organelle. Adaptation and cell survival in response to ERS requires a critical contribution by mitochondria and peroxisomes. During ERS responses, mitochondrial respiration increases to ameliorate reactive oxygen species (ROS) accumulation. We now show in yeast that peroxisome abundance also increases to promote an adaptive response. In pox1Δ cells, which are defective in peroxisomal β-oxidation of fatty acids, the respiratory response to ERS is impaired and ROS accrues. However, the respiratory response to ERS is rescued and ROS production is mitigated in pox1Δ cells overexpressing Mpc1, the mitochondrial pyruvate carrier that provides another source of acetyl CoA to fuel the tricarboxylic acid cycle and oxidative phosphorylation. Using proteomics, select mitochondrial proteins were identified that undergo upregulation upon ERS to remodel the respiratory machinery. The abundance of several peroxisome-based proteins was also increased, corroborating the role of peroxisomes in ERS adaptation. Finally, ERS stimulates assembly of respiratory complexes into higher-order supercomplexes, underlying increased electron transfer efficiency. Our results highlight peroxisomal and mitochondrial support for ERS adaptation to favor cell survival.
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24
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Liu C, Zhou W, Liu Q, Peng Z. Hypoglycemia with lactic acidosis caused by a new MRPS2 gene mutation in a Chinese girl: a case report. BMC Endocr Disord 2022; 22:15. [PMID: 34991560 PMCID: PMC8734237 DOI: 10.1186/s12902-021-00924-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Accepted: 12/21/2021] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Mitochondrial ribosomal protein S2 (MRPS2) gene mutation, which is related to severe hypoglycemia and lactic acidosis, is rarely reported globally. CASE PRESENTATION We report a case of a new MRPS2 gene mutation in a Chinese girl who presented with hypoglycemia and lactic acidosis. A homozygous C.412C > G variant that could cause complex oxidative phosphorylation deficiency and had not been reported before was identified. The clinical manifestations included recurrent vomiting, hypoglycemia, lactic acidosis, sensorineural hearing loss, and gall bladder calculi. Hypoglycemia and lactic acidosis improved after the administration of sugary liquid and supportive treatments. CONCLUSIONS Recurrent hypoglycemia with lactic acidosis and sensorineural hearing loss should lead to suspicion of mitochondrial defects and the early refinement of genetic tests.
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Affiliation(s)
- ChangZhi Liu
- Xiangxi Tujia and Miao Autonomous Prefecture People's Hospital, Jishou, China
| | - WeiRan Zhou
- Jinan Children's Hospital (Qilu Children's Hospital of Shandong University), Jinan, China.
| | - QuanE Liu
- Xiangxi Tujia and Miao Autonomous Prefecture People's Hospital, Jishou, China
| | - ZaiXin Peng
- Xiangxi Tujia and Miao Autonomous Prefecture People's Hospital, Jishou, China
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25
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Herbert CJ, Labarre-Mariotte S, Cornu D, Sophie C, Panozzo C, Michel T, Dujardin G, Bonnefoy N. Translational activators and mitoribosomal isoforms cooperate to mediate mRNA-specific translation in Schizosaccharomyces pombe mitochondria. Nucleic Acids Res 2021; 49:11145-11166. [PMID: 34634819 PMCID: PMC8565316 DOI: 10.1093/nar/gkab789] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 08/24/2021] [Accepted: 10/05/2021] [Indexed: 11/12/2022] Open
Abstract
Mitochondrial mRNAs encode key subunits of the oxidative phosphorylation complexes that produce energy for the cell. In Saccharomyces cerevisiae, mitochondrial translation is under the control of translational activators, specific to each mRNA. In Schizosaccharomyces pombe, which more closely resembles the human system by its mitochondrial DNA structure and physiology, most translational activators appear to be either lacking, or recruited for post-translational functions. By combining bioinformatics, genetic and biochemical approaches we identified two interacting factors, Cbp7 and Cbp8, controlling Cytb production in S. pombe. We show that their absence affects cytb mRNA stability and impairs the detection of the Cytb protein. We further identified two classes of Cbp7/Cbp8 partners and showed that they modulated Cytb or Cox1 synthesis. First, two isoforms of bS1m, a protein of the small mitoribosomal subunit, that appear mutually exclusive and confer translational specificity. Second, a complex of four proteins dedicated to Cox1 synthesis, which includes an RNA helicase that interacts with the mitochondrial ribosome. Our results suggest that S. pombe contains, in addition to complexes of translational activators, a heterogeneous population of mitochondrial ribosomes that could specifically modulate translation depending on the mRNA translated, in order to optimally balance the production of different respiratory complex subunits.
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Affiliation(s)
- Christopher J Herbert
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Sylvie Labarre-Mariotte
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - David Cornu
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Cyrielle Sophie
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Cristina Panozzo
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Thomas Michel
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Geneviève Dujardin
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Nathalie Bonnefoy
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
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26
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Verma Y, Mehra U, Pandey DK, Kar J, Pérez-Martinez X, Jana SS, Datta K. MRX8, the conserved mitochondrial YihA GTPase family member, is required for de novo Cox1 synthesis at suboptimal temperatures in Saccharomyces cerevisiae. Mol Biol Cell 2021; 32:ar16. [PMID: 34432493 PMCID: PMC8693954 DOI: 10.1091/mbc.e20-07-0457] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The synthesis of Cox1, the conserved catalytic-core subunit of Complex IV, a multisubunit machinery of the mitochondrial oxidative phosphorylation (OXPHOS) system under environmental stress, has not been sufficiently addressed. In this study, we show that the putative YihA superfamily GTPase, Mrx8, is a bona fide mitochondrial protein required for Cox1 translation initiation and elongation during suboptimal growth condition at 16°C. Mrx8 was found in a complex with mitochondrial ribosomes, consistent with a role in protein synthesis. Cells expressing mutant Mrx8 predicted to be defective in guanine nucleotide binding and hydrolysis were compromised for robust cellular respiration. We show that the requirement of Pet309 and Mss51 for cellular respiration is not bypassed by overexpression of Mrx8 and vice versa. Consistently the ribosomal association of Mss51 is independent of Mrx8. Significantly, we find that GTPBP8, the human orthologue, complements the loss of cellular respiration in Δmrx8 cells and GTPBP8 localizes to the mitochondria in mammalian cells. This strongly suggests a universal role of the MRX8 family of proteins in regulating mitochondrial function.
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Affiliation(s)
- Yash Verma
- Department of Genetics, University of Delhi South Campus, New Delhi 110021, India
| | - Upasana Mehra
- Department of Genetics, University of Delhi South Campus, New Delhi 110021, India
| | | | - Joy Kar
- School of Biological Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Xochitl Pérez-Martinez
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
| | - Siddhartha S Jana
- School of Biological Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Kaustuv Datta
- Department of Genetics, University of Delhi South Campus, New Delhi 110021, India
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27
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Ng KY, Richter U, Jackson CB, Seneca S, Battersby BJ. Translation of MT-ATP6 pathogenic variants reveals distinct regulatory consequences from the co-translational quality control of mitochondrial protein synthesis. Hum Mol Genet 2021; 31:1230-1241. [PMID: 34718584 PMCID: PMC9029222 DOI: 10.1093/hmg/ddab314] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 10/15/2021] [Accepted: 10/18/2021] [Indexed: 11/16/2022] Open
Abstract
Pathogenic variants that disrupt human mitochondrial protein synthesis are associated with a clinically heterogeneous group of diseases. Despite an impairment in oxidative phosphorylation being a common phenotype, the underlying molecular pathogenesis is more complex than simply a bioenergetic deficiency. Currently, we have limited mechanistic understanding on the scope by which a primary defect in mitochondrial protein synthesis contributes to organelle dysfunction. Since the proteins encoded in the mitochondrial genome are hydrophobic and need co-translational insertion into a lipid bilayer, responsive quality control mechanisms are required to resolve aberrations that arise with the synthesis of truncated and misfolded proteins. Here, we show that defects in the OXA1L-mediated insertion of MT-ATP6 nascent chains into the mitochondrial inner membrane are rapidly resolved by the AFG3L2 protease complex. Using pathogenic MT-ATP6 variants, we then reveal discrete steps in this quality control mechanism and the differential functional consequences to mitochondrial gene expression. The inherent ability of a given cell type to recognize and resolve impairments in mitochondrial protein synthesis may in part contribute at the molecular level to the wide clinical spectrum of these disorders.
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Affiliation(s)
- Kah Ying Ng
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Uwe Richter
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland.,Wellcome Centre for Mitochondrial Research, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Christopher B Jackson
- Department of Biochemistry and Developmental Biology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Sara Seneca
- Center for Medical Genetics/Research Center Reproduction and Genetics, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel (VUB), Brussels, Belgium
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28
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IRC3 regulates mitochondrial translation in response to metabolic cues in Saccharomyces cerevisiae. Mol Cell Biol 2021; 41:e0023321. [PMID: 34398681 DOI: 10.1128/mcb.00233-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mitochondrial oxidative phosphorylation (OXPHOS) enzymes are made up of dual genetic origin. Mechanisms regulating the expression of nuclear-encoded OXPHOS subunits in response to metabolic cues (glucose vs. glycerol), is significantly understood while regulation of mitochondrially encoded OXPHOS subunits is poorly defined. Here, we show that IRC3 a DEAD/H box helicase, previously implicated in mitochondrial DNA maintenance, is central to integrating metabolic cues with mitochondrial translation. Irc3 associates with mitochondrial small ribosomal subunit in cells consistent with its role in regulating translation elongation based on Arg8m reporter system. IRC3 deleted cells retained mitochondrial DNA despite growth defect on glycerol plates. Glucose grown Δirc3ρ+ and irc3 temperature-sensitive cells at 370C have reduced translation rates from majority of mRNAs. In contrast, when galactose was the carbon source, reduction in mitochondrial translation was observed predominantly from Cox1 mRNA in Δirc3ρ+ but no defect was observed in irc3 temperature-sensitive cells, at 370C. In support, of a model whereby IRC3 responds to metabolic cues to regulate mitochondrial translation, suppressors of Δirc3 isolated for restoration of growth on glycerol media restore mitochondrial protein synthesis differentially in presence of glucose vs. glycerol.
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29
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Xu X, Tassone B, Ostano P, Katarkar A, Proust T, Joseph JM, Riganti C, Chiorino G, Kutalik Z, Lefort K, Dotto GP. HSD17B7 gene in self-renewal and oncogenicity of keratinocytes from Black versus White populations. EMBO Mol Med 2021; 13:e14133. [PMID: 34185380 PMCID: PMC8261506 DOI: 10.15252/emmm.202114133] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 05/19/2021] [Accepted: 05/20/2021] [Indexed: 01/09/2023] Open
Abstract
Human populations of Black African ancestry have a relatively high risk of aggressive cancer types, including keratinocyte-derived squamous cell carcinomas (SCCs). We show that primary keratinocytes (HKCs) from Black African (Black) versus White Caucasian (White) individuals have on average higher oncogenic and self-renewal potential, which are inversely related to mitochondrial electron transfer chain activity and ATP and ROS production. HSD17B7 is the top-ranked differentially expressed gene in HKCs and Head/Neck SCCs from individuals of Black African versus Caucasian ancestries, with several ancestry-specific eQTLs linked to its expression. Mirroring the differences between Black and White HKCs, modulation of the gene, coding for an enzyme involved in sex steroid and cholesterol biosynthesis, determines HKC and SCC cell proliferation and oncogenicity as well as mitochondrial OXPHOS activity. Overall, the findings point to a targetable determinant of cancer susceptibility among different human populations, amenable to prevention and management of the disease.
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Affiliation(s)
- Xiaoying Xu
- Department of Biochemistry, University of Lausanne, Epalinges, Switzerland
| | - Beatrice Tassone
- Department of Biochemistry, University of Lausanne, Epalinges, Switzerland
| | - Paola Ostano
- Cancer Genomics Laboratory, Fondazione Edo ed Elvo Tempia, Biella, Italy
| | - Atul Katarkar
- Department of Biochemistry, University of Lausanne, Epalinges, Switzerland
| | - Tatiana Proust
- Department of Biochemistry, University of Lausanne, Epalinges, Switzerland
| | - Jean-Marc Joseph
- Division of Pediatric Surgery, Women-Mother-Child Department, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Chiara Riganti
- Department of Oncology, University of Turin, Turin, Italy
| | - Giovanna Chiorino
- Cancer Genomics Laboratory, Fondazione Edo ed Elvo Tempia, Biella, Italy
| | - Zoltan Kutalik
- University Center for Primary Care and Public Health, University of Lausanne, Lausanne, Switzerland
| | - Karine Lefort
- Department of Biochemistry, University of Lausanne, Epalinges, Switzerland
| | - Gian Paolo Dotto
- Department of Biochemistry, University of Lausanne, Epalinges, Switzerland
- Cutaneous Biology Research Center, Massachusetts General Hospital, Charlestown, MA, USA
- International Cancer Prevention Institute, Epalinges, Switzerland
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30
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Le Vasseur M, Friedman J, Jost M, Xu J, Yamada J, Kampmann M, Horlbeck MA, Salemi MR, Phinney BS, Weissman JS, Nunnari J. Genome-wide CRISPRi screening identifies OCIAD1 as a prohibitin client and regulatory determinant of mitochondrial Complex III assembly in human cells. eLife 2021; 10:67624. [PMID: 34034859 PMCID: PMC8154037 DOI: 10.7554/elife.67624] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 05/10/2021] [Indexed: 01/01/2023] Open
Abstract
Dysfunction of the mitochondrial electron transport chain (mETC) is a major cause of human mitochondrial diseases. To identify determinants of mETC function, we screened a genome-wide human CRISPRi library under oxidative metabolic conditions with selective inhibition of mitochondrial Complex III and identified ovarian carcinoma immunoreactive antigen (OCIA) domain-containing protein 1 (OCIAD1) as a Complex III assembly factor. We find that OCIAD1 is an inner mitochondrial membrane protein that forms a complex with supramolecular prohibitin assemblies. Our data indicate that OCIAD1 is required for maintenance of normal steady-state levels of Complex III and the proteolytic processing of the catalytic subunit cytochrome c1 (CYC1). In OCIAD1 depleted mitochondria, unprocessed CYC1 is hemylated and incorporated into Complex III. We propose that OCIAD1 acts as an adaptor within prohibitin assemblies to stabilize and/or chaperone CYC1 and to facilitate its proteolytic processing by the IMMP2L protease.
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Affiliation(s)
- Maxence Le Vasseur
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of California, Davis, Davis, United States
| | - Jonathan Friedman
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of California, Davis, Davis, United States.,Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Marco Jost
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, United States.,Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, United States.,Department of Microbiology and Immunology, University of California at San Francisco, San Francisco, United States
| | - Jiawei Xu
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of California, Davis, Davis, United States
| | - Justin Yamada
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of California, Davis, Davis, United States
| | - Martin Kampmann
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, United States.,Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, United States.,Institute for Neurodegenerative Diseases and Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, United States.,Chan-Zuckerberg Biohub, San Francisco, United States
| | - Max A Horlbeck
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, United States.,Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, United States
| | - Michelle R Salemi
- Proteomics Core Facility, University of California, Davis, Davis, United States
| | - Brett S Phinney
- Proteomics Core Facility, University of California, Davis, Davis, United States
| | - Jonathan S Weissman
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, United States.,Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, United States.,Whitehead Institute, Cambridge, United States.,Department of Biology, Massachusetts Institute of Technology, Cambridge, United States
| | - Jodi Nunnari
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of California, Davis, Davis, United States
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31
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The pentatricopeptide repeat protein Rmd9 recognizes the dodecameric element in the 3'-UTRs of yeast mitochondrial mRNAs. Proc Natl Acad Sci U S A 2021; 118:2009329118. [PMID: 33876744 DOI: 10.1073/pnas.2009329118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Stabilization of messenger RNA is an important step in posttranscriptional gene regulation. In the nucleus and cytoplasm of eukaryotic cells it is generally achieved by 5' capping and 3' polyadenylation, whereas additional mechanisms exist in bacteria and organelles. The mitochondrial mRNAs in the yeast Saccharomyces cerevisiae comprise a dodecamer sequence element that confers RNA stability and 3'-end processing via an unknown mechanism. Here, we isolated the protein that binds the dodecamer and identified it as Rmd9, a factor that is known to stabilize yeast mitochondrial RNA. We show that Rmd9 associates with mRNA around dodecamer elements in vivo and that recombinant Rmd9 specifically binds the element in vitro. The crystal structure of Rmd9 bound to its dodecamer target reveals that Rmd9 belongs to the family of pentatricopeptide (PPR) proteins and uses a previously unobserved mode of specific RNA recognition. Rmd9 protects RNA from degradation by the mitochondrial 3'-exoribonuclease complex mtEXO in vitro, indicating that recognition and binding of the dodecamer element by Rmd9 confers stability to yeast mitochondrial mRNAs.
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32
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Salvatori R, Aftab W, Forne I, Imhof A, Ott M, Singh AP. Mapping protein networks in yeast mitochondria using proximity-dependent biotin identification coupled to proteomics. STAR Protoc 2020; 1:100219. [PMID: 33377112 PMCID: PMC7757666 DOI: 10.1016/j.xpro.2020.100219] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Proximity-dependent biotin identification (BioID) permits biotinylation of proteins interacting directly, indirectly, or just localized in proximity of a protein of interest (bait). Here, we describe how BioID coupled to proteomics and network biology can be used to map protein proximities in yeast mitochondria, aiding in visualization of complex protein-protein interaction landscapes. For complete information on the use and execution of this protocol, please refer to Singh et al., 2020.
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Affiliation(s)
- Roger Salvatori
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm 10691, Sweden
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg 40530, Sweden
| | - Wasim Aftab
- BioMedical Center, Faculty of Medicine, Ludwig Maximilians University of Munich, Planegg-Martinsried 82152, Germany
- Graduate School for Quantitative Biosciences (QBM), Ludwig Maximilians University of Munich, Munich 81377, Germany
| | - Ignasi Forne
- BioMedical Center, Faculty of Medicine, Ludwig Maximilians University of Munich, Planegg-Martinsried 82152, Germany
| | - Axel Imhof
- BioMedical Center, Faculty of Medicine, Ludwig Maximilians University of Munich, Planegg-Martinsried 82152, Germany
- Corresponding author
| | - Martin Ott
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm 10691, Sweden
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg 40530, Sweden
- Corresponding author
| | - Abeer Prakash Singh
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm 10691, Sweden
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg 40530, Sweden
- Corresponding author
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