1
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Shuvalov A, Klishin A, Biziaev N, Shuvalova E, Alkalaeva E. Functional Activity of Isoform 2 of Human eRF1. Int J Mol Sci 2024; 25:7997. [PMID: 39063238 PMCID: PMC11277123 DOI: 10.3390/ijms25147997] [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: 05/26/2024] [Revised: 06/29/2024] [Accepted: 07/12/2024] [Indexed: 07/28/2024] Open
Abstract
Eukaryotic release factor eRF1, encoded by the ETF1 gene, recognizes stop codons and induces peptide release during translation termination. ETF1 produces several different transcripts as a result of alternative splicing, from which two eRF1 isoforms can be formed. Isoform 1 codes well-studied canonical eRF1, and isoform 2 is 33 amino acid residues shorter than isoform 1 and completely unstudied. Using a reconstituted mammalian in vitro translation system, we showed that the isoform 2 of human eRF1 is also involved in translation. We showed that eRF1iso2 can interact with the ribosomal subunits and pre-termination complex. However, its codon recognition and peptide release activities have decreased. Additionally, eRF1 isoform 2 exhibits unipotency to UGA. We found that eRF1 isoform 2 interacts with eRF3a but stimulated its GTPase activity significantly worse than the main isoform eRF1. Additionally, we studied the eRF1 isoform 2 effect on stop codon readthrough and translation in a cell-free translation system. We observed that eRF1 isoform 2 suppressed stop codon readthrough of the uORFs and decreased the efficiency of translation of long coding sequences. Based on these data, we assumed that human eRF1 isoform 2 can be involved in the regulation of translation termination. Moreover, our data support previously stated hypotheses that the GTS loop is important for the multipotency of eRF1 to all stop codons. Whereas helix α1 of the N-domain eRF1 is proposed to be involved in conformational rearrangements of eRF1 in the A-site of the ribosome that occur after GTP hydrolysis by eRF3, which ensure hydrolysis of peptidyl-tRNA at the P site of the ribosome.
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Affiliation(s)
- Alexey Shuvalov
- Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, 119991 Moscow, Russia; (A.S.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, 119991 Moscow, Russia
| | - Alexandr Klishin
- Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, 119991 Moscow, Russia; (A.S.)
| | - Nikita Biziaev
- Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, 119991 Moscow, Russia; (A.S.)
| | - Ekaterina Shuvalova
- Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, 119991 Moscow, Russia; (A.S.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, 119991 Moscow, Russia
| | - Elena Alkalaeva
- Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, 119991 Moscow, Russia; (A.S.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, 119991 Moscow, Russia
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2
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McGirr T, Onar O, Jafarnejad SM. Dysregulated ribosome quality control in human diseases. FEBS J 2024. [PMID: 38949989 DOI: 10.1111/febs.17217] [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: 02/12/2024] [Revised: 05/31/2024] [Accepted: 06/20/2024] [Indexed: 07/03/2024]
Abstract
Precise regulation of mRNA translation is of fundamental importance for maintaining homeostasis. Conversely, dysregulated general or transcript-specific translation, as well as abnormal translation events, have been linked to a multitude of diseases. However, driven by the misconception that the transient nature of mRNAs renders their abnormalities inconsequential, the importance of mechanisms that monitor the quality and fidelity of the translation process has been largely overlooked. In recent years, there has been a dramatic shift in this paradigm, evidenced by several seminal discoveries on the role of a key mechanism in monitoring the quality of mRNA translation - namely, Ribosome Quality Control (RQC) - in the maintenance of homeostasis and the prevention of diseases. Here, we will review recent advances in the field and emphasize the biological significance of the RQC mechanism, particularly its implications in human diseases.
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Affiliation(s)
- Tom McGirr
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, UK
| | - Okan Onar
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, UK
- Department of Biology, Faculty of Science, Ankara University, Turkey
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3
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Fernandez SG, Ferguson L, Ingolia NT. Ribosome rescue factor PELOTA modulates translation start site choice for C/EBPα protein isoforms. Life Sci Alliance 2024; 7:e202302501. [PMID: 38803235 PMCID: PMC11109482 DOI: 10.26508/lsa.202302501] [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: 11/28/2023] [Revised: 04/15/2024] [Accepted: 04/16/2024] [Indexed: 05/29/2024] Open
Abstract
Translation initiation at alternative start sites can dynamically control the synthesis of two or more functionally distinct protein isoforms from a single mRNA. Alternate isoforms of the developmental transcription factor CCAAT/enhancer-binding protein α (C/EBPα) produced from different start sites exert opposing effects during myeloid cell development. This choice between alternative start sites depends on sequence features of the CEBPA transcript, including a regulatory uORF, but the molecular basis is not fully understood. Here, we identify the factors that affect C/EBPα isoform choice using a sensitive and quantitative two-color fluorescent reporter coupled with CRISPRi screening. Our screen uncovered a role of the ribosome rescue factor PELOTA (PELO) in promoting the expression of the longer C/EBPα isoform by directly removing inhibitory unrecycled ribosomes and through indirect effects mediated by the mechanistic target of rapamycin kinase. Our work uncovers further links between ribosome recycling and translation reinitiation that regulate a key transcription factor, with implications for normal hematopoiesis and leukemogenesis.
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Affiliation(s)
- Samantha G Fernandez
- https://ror.org/01an7q238 Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Lucas Ferguson
- https://ror.org/01an7q238 Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
- https://ror.org/01an7q238 Center for Computational Biology and California Institute for Quantitative Biosciences, University of California, Berkeley, CA, USA
| | - Nicholas T Ingolia
- https://ror.org/01an7q238 Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
- https://ror.org/01an7q238 Center for Computational Biology and California Institute for Quantitative Biosciences, University of California, Berkeley, CA, USA
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4
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Coelho JPL, Yip MCJ, Oltion K, Taunton J, Shao S. The eRF1 degrader SRI-41315 acts as a molecular glue at the ribosomal decoding center. Nat Chem Biol 2024; 20:877-884. [PMID: 38172604 PMCID: PMC11253071 DOI: 10.1038/s41589-023-01521-0] [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: 04/26/2023] [Accepted: 12/04/2023] [Indexed: 01/05/2024]
Abstract
Translation termination is an essential cellular process, which is also of therapeutic interest for diseases that manifest from premature stop codons. In eukaryotes, translation termination requires eRF1, which recognizes stop codons, catalyzes the release of nascent proteins from ribosomes and facilitates ribosome recycling. The small molecule SRI-41315 triggers eRF1 degradation and enhances translational readthrough of premature stop codons. However, the mechanism of action of SRI-41315 on eRF1 and translation is not known. Here we report cryo-EM structures showing that SRI-41315 acts as a metal-dependent molecular glue between the N domain of eRF1 responsible for stop codon recognition and the ribosomal subunit interface near the decoding center. Retention of eRF1 on ribosomes by SRI-41315 leads to ribosome collisions, eRF1 ubiquitylation and a higher frequency of translation termination at near-cognate stop codons. Our findings reveal a new mechanism of release factor inhibition and additional implications for pharmacologically targeting eRF1.
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Affiliation(s)
- João P L Coelho
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Matthew C J Yip
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Keely Oltion
- Chemistry and Chemical Biology Graduate Program, University of California San Francisco, San Francisco, CA, USA
| | - Jack Taunton
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA
| | - Sichen Shao
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
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5
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Turnbull K, Paternoga H, von der Weth E, Egorov AA, Pochopien AA, Zhang Y, Nersisyan L, Margus T, Johansson MJ, Pelechano V, Wilson DN, Hauryliuk V. The ABCF ATPase New1 resolves translation termination defects associated with specific tRNA Arg and tRNA Lys isoacceptors in the P site. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.29.596377. [PMID: 38854126 PMCID: PMC11160720 DOI: 10.1101/2024.05.29.596377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
The efficiency of translation termination is determined by the nature of the stop codon as well as its context. In eukaryotes, recognition of the A-site stop codon and release of the polypeptide are mediated by release factors eRF1 and eRF3, respectively. Translation termination is modulated by other factors which either directly interact with release factors or bind to the E-site and modulate the activity of the peptidyl transferase center. Previous studies suggested that the Saccharomyces cerevisiae ABCF ATPase New1 is involved in translation termination and/or ribosome recycling, however, the exact function remained unclear. Here, we have applied 5PSeq, single-particle cryo-EM and readthrough reporter assays to provide insight into the biological function of New1. We show that the lack of New1 results in ribosomal stalling at stop codons preceded by a lysine or arginine codon and that the stalling is not defined by the nature of the C-terminal amino acid but rather by the identity of the tRNA isoacceptor in the P-site. Collectively, our results suggest that translation termination is inefficient when ribosomes have specific tRNA isoacceptors in the P-site and that the recruitment of New1 rescues ribosomes at these problematic termination contexts.
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Affiliation(s)
- Kathryn Turnbull
- Department of Clinical Microbiology, Rigshospitalet, 2200 Copenhagen, Denmark
| | - Helge Paternoga
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany
| | - Esther von der Weth
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Artyom A. Egorov
- Department of Experimental Medicine, University of Lund, 221 84 Lund, Sweden
| | - Agnieszka A Pochopien
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany
| | - Yujie Zhang
- SciLifeLab, Department of Microbiology, Tumor and Cell Biology. Karolinska Institutet, Solna, Sweden
| | - Lilit Nersisyan
- SciLifeLab, Department of Microbiology, Tumor and Cell Biology. Karolinska Institutet, Solna, Sweden
- Armenian Bioinformatics Institute, Yerevan, Armenia
- Institute of Molecular Biology, National Academy of Sciences of Armenia, Yerevan, Armenia
| | | | | | - Vicent Pelechano
- SciLifeLab, Department of Microbiology, Tumor and Cell Biology. Karolinska Institutet, Solna, Sweden
| | - Daniel N. Wilson
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany
| | - Vasili Hauryliuk
- Department of Experimental Medicine, University of Lund, 221 84 Lund, Sweden
- University of Tartu, Institute of Technology, 50411 Tartu, Estonia
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6
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Jendruchová K, Gaikwad S, Poncová K, Gunišová S, Valášek LS, Hinnebusch AG. Impacts of yeast Tma20/MCTS1, Tma22/DENR and Tma64/eIF2D on translation reinitiation and ribosome recycling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.06.583729. [PMID: 38903097 PMCID: PMC11188067 DOI: 10.1101/2024.03.06.583729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
Recycling of 40S ribosomal subunits following translation termination, entailing release of deacylated tRNA and dissociation of the empty 40S subunit from mRNA, involves yeast Tma20/Tma22 heterodimer and Tma64, counterparts of mammalian MCTS1/DENR and eIF2D. MCTS1/DENR enhance reinitiation at short upstream open reading frames (uORFs) harboring penultimate codons that confer dependence on these factors in bulk 40S recycling. Tma factors, by contrast, inhibited reinitiation at particular uORFs in extracts; however, their roles at regulatory uORFs in vivo were unknown. We examined effects of eliminating Tma proteins on reinitiation at regulatory uORFs mediating translational control of GCN4 optimized for either promoting (uORF1) or preventing (uORF4) reinitiation. We found that the Tma proteins generally impede reinitiation at native uORF4 and uORF4 variants equipped with various penultimate codons regardless of their Tma-dependence in bulk recycling. The Tma factors have no effect on reinitiation at native uORF1, and equipping uORF1 with Tma-dependent penultimate codons generally did not confer Tma-dependent reinitiation; nor did converting the uORFs to AUG-stop elements. Thus, effects of the Tma proteins vary depending on the reinitiation potential of the uORF and the penultimate codon, but unlike in mammals, are not principally dictated by the Tma-dependence of the codon in bulk 40S recycling.
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Affiliation(s)
- Kristína Jendruchová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20, Prague, the Czech Republic
- Faculty of Science, Charles University, Albertov 6, 128 00 Prague, Czech Republic
| | - Swati Gaikwad
- Divsion of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kristýna Poncová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20, Prague, the Czech Republic
| | - Stanislava Gunišová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20, Prague, the Czech Republic
| | - Leoš Shivaya Valášek
- Laboratory of Regulation of Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Videnska 1083, 142 20, Prague, the Czech Republic
| | - Alan G Hinnebusch
- Divsion of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
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7
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Pacheco M, D’Orazio KN, Lessen LN, Veltri AJ, Neiman Z, Loll-Krippleber R, Brown GW, Green R. Genetic screens in Saccharomyces cerevisiae identify a role for 40S ribosome recycling factors Tma20 and Tma22 in nonsense-mediated decay. G3 (BETHESDA, MD.) 2024; 14:jkad295. [PMID: 38198768 PMCID: PMC10917514 DOI: 10.1093/g3journal/jkad295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 08/29/2023] [Accepted: 12/06/2023] [Indexed: 01/12/2024]
Abstract
The decay of messenger RNA with a premature termination codon by nonsense-mediated decay (NMD) is an important regulatory pathway for eukaryotes and an essential pathway in mammals. NMD is typically triggered by the ribosome terminating at a stop codon that is aberrantly distant from the poly-A tail. Here, we use a fluorescence screen to identify factors involved in NMD in Saccharomyces cerevisiae. In addition to the known NMD factors, including the entire UPF family (UPF1, UPF2, and UPF3), as well as NMD4 and EBS1, we identify factors known to function in posttermination recycling and characterize their contribution to NMD. These observations in S. cerevisiae expand on data in mammals indicating that the 60S recycling factor ABCE1 is important for NMD by showing that perturbations in factors implicated in 40S recycling also correlate with a loss of NMD.
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Affiliation(s)
- Miguel Pacheco
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Karole N D’Orazio
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Laura N Lessen
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Anthony J Veltri
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Zachary Neiman
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Raphael Loll-Krippleber
- Department of Biochemistry and Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Grant W Brown
- Department of Biochemistry and Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Rachel Green
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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8
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Williams TD, Rousseau A. Translation regulation in response to stress. FEBS J 2024. [PMID: 38308808 DOI: 10.1111/febs.17076] [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: 11/09/2023] [Revised: 12/07/2023] [Accepted: 01/22/2024] [Indexed: 02/05/2024]
Abstract
Cell stresses occur in a wide variety of settings: in disease, during industrial processes, and as part of normal day-to-day rhythms. Adaptation to these stresses requires cells to alter their proteome. Cells modify the proteins they synthesize to aid proteome adaptation. Changes in both mRNA transcription and translation contribute to altered protein synthesis. Here, we discuss the changes in translational mechanisms that occur following the onset of stress, and the impact these have on stress adaptation.
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Affiliation(s)
- Thomas D Williams
- MRC-PPU, School of Life Sciences, University of Dundee, UK
- Sir William Dunn School of Pathology, University of Oxford, UK
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9
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Sherwood DR, Kenny-Ganzert IW, Balachandar Thendral S. Translational regulation of cell invasion through extracellular matrix-an emerging role for ribosomes. F1000Res 2023; 12:1528. [PMID: 38628976 PMCID: PMC11019292 DOI: 10.12688/f1000research.143519.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/22/2023] [Indexed: 04/19/2024] Open
Abstract
Many developmental and physiological processes require cells to invade and migrate through extracellular matrix barriers. This specialized cellular behavior is also misregulated in many diseases, such as immune disorders and cancer. Cell invasive activity is driven by pro-invasive transcriptional networks that activate the expression of genes encoding numerous different proteins that expand and regulate the cytoskeleton, endomembrane system, cell adhesion, signaling pathways, and metabolic networks. While detailed mechanistic studies have uncovered crucial insights into pro-invasive transcriptional networks and the distinct cell biological attributes of invasive cells, less is known about how invasive cells modulate mRNA translation to meet the robust, dynamic, and unique protein production needs of cell invasion. In this review we outline known modes of translation regulation promoting cell invasion and focus on recent studies revealing elegant mechanisms that expand ribosome biogenesis within invasive cells to meet the increased protein production requirements to invade and migrate through extracellular matrix barriers.
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10
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Alagar Boopathy LR, Beadle E, Garcia-Bueno Rico A, Vera M. Proteostasis regulation through ribosome quality control and no-go-decay. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1809. [PMID: 37488089 DOI: 10.1002/wrna.1809] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 06/14/2023] [Accepted: 06/30/2023] [Indexed: 07/26/2023]
Abstract
Cell functionality relies on the existing pool of proteins and their folding into functional conformations. This is achieved through the regulation of protein synthesis, which requires error-free mRNAs and ribosomes. Ribosomes are quality control hubs for mRNAs and proteins. Problems during translation elongation slow down the decoding rate, leading to ribosome halting and the eventual collision with the next ribosome. Collided ribosomes form a specific disome structure recognized and solved by ribosome quality control (RQC) mechanisms. RQC pathways orchestrate the degradation of the problematic mRNA by no-go decay and the truncated nascent peptide, the repression of translation initiation, and the recycling of the stalled ribosomes. All these events maintain protein homeostasis and return valuable ribosomes to translation. As such, cell homeostasis and function are maintained at the mRNA level by preventing the production of aberrant or unnecessary proteins. It is becoming evident that the crosstalk between RQC and the protein homeostasis network is vital for cell function, as the absence of RQC components leads to the activation of stress response and neurodegenerative diseases. Here, we review the molecular events of RQC discovered through well-designed stalling reporters. Given the impact of RQC in proteostasis, we discuss the relevance of identifying endogenous mRNA regulated by RQC and their preservation in stress conditions. This article is categorized under: RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms Translation > Regulation.
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Affiliation(s)
| | - Emma Beadle
- Department of Biochemistry, McGill University, Montreal, Canada
| | | | - Maria Vera
- Department of Biochemistry, McGill University, Montreal, Canada
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11
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Tomecki R, Drazkowska K, Kobylecki K, Tudek A. SKI complex: A multifaceted cytoplasmic RNA exosome cofactor in mRNA metabolism with links to disease, developmental processes, and antiviral responses. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1795. [PMID: 37384835 DOI: 10.1002/wrna.1795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 04/26/2023] [Accepted: 05/01/2023] [Indexed: 07/01/2023]
Abstract
RNA stability and quality control are integral parts of gene expression regulation. A key factor shaping eukaryotic transcriptomes, mainly via 3'-5' exoribonucleolytic trimming or degradation of diverse transcripts in nuclear and cytoplasmic compartments, is the RNA exosome. Precise exosome targeting to various RNA molecules requires strict collaboration with specialized auxiliary factors, which facilitate interactions with its substrates. The predominant class of cytoplasmic RNA targeted by the exosome are protein-coding transcripts, which are carefully scrutinized for errors during translation. Normal, functional mRNAs are turned over following protein synthesis by the exosome or by Xrn1 5'-3'-exonuclease, acting in concert with Dcp1/2 decapping complex. In turn, aberrant transcripts are eliminated by dedicated surveillance pathways, triggered whenever ribosome translocation is impaired. Cytoplasmic 3'-5' mRNA decay and surveillance are dependent on the tight cooperation between the exosome and its evolutionary conserved co-factor-the SKI (superkiller) complex (SKIc). Here, we summarize recent findings from structural, biochemical, and functional studies of SKIc roles in controlling cytoplasmic RNA metabolism, including links to various cellular processes. Mechanism of SKIc action is illuminated by presentation of its spatial structure and details of its interactions with exosome and ribosome. Furthermore, contribution of SKIc and exosome to various mRNA decay pathways, usually converging on recycling of ribosomal subunits, is delineated. A crucial physiological role of SKIc is emphasized by describing association between its dysfunction and devastating human disease-a trichohepatoenteric syndrome (THES). Eventually, we discuss SKIc functions in the regulation of antiviral defense systems, cell signaling and developmental transitions, emerging from interdisciplinary investigations. This article is categorized under: RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms RNA Turnover and Surveillance > Regulation of RNA Stability RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes.
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Affiliation(s)
- Rafal Tomecki
- Laboratory of RNA Processing and Decay, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Karolina Drazkowska
- Laboratory of Epitranscriptomics, Department of Environmental Microbiology and Biotechnology, Institute of Microbiology, Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland
| | - Kamil Kobylecki
- Laboratory of RNA Processing and Decay, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Agnieszka Tudek
- Laboratory of RNA Processing and Decay, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
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12
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Meydan S, Guydosh NR. Is there a localized role for translational quality control? RNA (NEW YORK, N.Y.) 2023; 29:1623-1643. [PMID: 37582617 PMCID: PMC10578494 DOI: 10.1261/rna.079683.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 07/26/2023] [Indexed: 08/17/2023]
Abstract
It is known that mRNAs and the machinery that translates them are not uniformly distributed throughout the cytoplasm. As a result, the expression of some genes is localized to particular parts of the cell and this makes it possible to carry out important activities, such as growth and signaling, in three-dimensional space. However, the functions of localized gene expression are not fully understood, and the underlying mechanisms that enable localized expression have not been determined in many cases. One consideration that could help in addressing these challenges is the role of quality control (QC) mechanisms that monitor translating ribosomes. On a global level, QC pathways are critical for detecting aberrant translation events, such as a ribosome that stalls while translating, and responding by activating stress pathways and resolving problematic ribosomes and mRNAs at the molecular level. However, it is unclear how these pathways, even when uniformly active throughout the cell, affect local translation. Importantly, some QC pathways have themselves been reported to be enriched in the proximity of particular organelles, but the extent of such localized activity remains largely unknown. Here, we describe the major QC pathways and review studies that have begun to explore their roles in localized translation. Given the limited data in this area, we also pose broad questions about the possibilities and limitations for how QC pathways could facilitate localized gene expression in the cell with the goal of offering ideas for future experimentation.
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Affiliation(s)
- Sezen Meydan
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
- National Institute of General Medical Sciences, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Nicholas R Guydosh
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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13
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Iyer KV, Müller M, Tittel LS, Winz ML. Molecular Highway Patrol for Ribosome Collisions. Chembiochem 2023; 24:e202300264. [PMID: 37382189 DOI: 10.1002/cbic.202300264] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 06/25/2023] [Accepted: 06/28/2023] [Indexed: 06/30/2023]
Abstract
During translation, messenger RNAs (mRNAs) are decoded by ribosomes which can stall for various reasons. These include chemical damage, codon composition, starvation, or translation inhibition. Trailing ribosomes can collide with stalled ribosomes, potentially leading to dysfunctional or toxic proteins. Such aberrant proteins can form aggregates and favor diseases, especially neurodegeneration. To prevent this, both eukaryotes and bacteria have evolved different pathways to remove faulty nascent peptides, mRNAs and defective ribosomes from the collided complex. In eukaryotes, ubiquitin ligases play central roles in triggering downstream responses and several complexes have been characterized that split affected ribosomes and facilitate degradation of the various components. As collided ribosomes signal translation stress to affected cells, in eukaryotes additional stress response pathways are triggered when collisions are sensed. These pathways inhibit translation and modulate cell survival and immune responses. Here, we summarize the current state of knowledge about rescue and stress response pathways triggered by ribosome collisions.
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Affiliation(s)
- Kaushik Viswanathan Iyer
- Institute for Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-University Mainz, Staudingerweg 5, 55128, Mainz, Germany
| | - Max Müller
- Institute for Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-University Mainz, Staudingerweg 5, 55128, Mainz, Germany
| | - Lena Sophie Tittel
- Institute for Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-University Mainz, Staudingerweg 5, 55128, Mainz, Germany
| | - Marie-Luise Winz
- Institute for Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-University Mainz, Staudingerweg 5, 55128, Mainz, Germany
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14
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Yu SX, Hu LQ, Yang LH, Zhang T, Dai RB, Zhang YJ, Xie ZP, Lin WH. RLI2 regulates Arabidopsis female gametophyte and embryo development by facilitating the assembly of the translational machinery. Cell Rep 2023; 42:112741. [PMID: 37421624 DOI: 10.1016/j.celrep.2023.112741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 04/01/2023] [Accepted: 06/20/2023] [Indexed: 07/10/2023] Open
Abstract
Eukaryotic protein translation is a complex process that requires the participation of different proteins. Defects in the translational machinery often result in embryonic lethality or severe growth defects. Here, we report that RNase L inhibitor 2/ATP-BINDING CASSETTE E2 (RLI2/ABCE2) regulates translation in Arabidopsis thaliana. Null mutation of rli2 is gametophytic and embryonic lethal, whereas knockdown of RLI2 causes pleiotropic developmental defects. RLI2 interacts with several translation-related factors. Knockdown of RLI2 affects the translational efficiency of a subset of proteins involved in translation regulation and embryo development, indicating that RLI2 has critical roles in these processes. In particular, RLI2 knockdown mutant exhibits decreased expression of genes involved in auxin signaling and female gametophyte and embryo development. Therefore, our results reveal that RLI2 facilitates assembly of the translational machinery and indirectly modulates auxin signaling to regulate plant growth and development.
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Affiliation(s)
- Shi-Xia Yu
- The Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; Shanghai Collaborative Innovation Center of Agri-Seeds/Joint Center for Single Cell Biology, Shanghai Jiao Tong University, Shanghai 200240, China; School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Li-Qin Hu
- The Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; Shanghai Collaborative Innovation Center of Agri-Seeds/Joint Center for Single Cell Biology, Shanghai Jiao Tong University, Shanghai 200240, China; School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Lu-Han Yang
- The Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Tao Zhang
- The Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ruo-Bing Dai
- Zhiyuan College, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yan-Jie Zhang
- The Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Zhi-Ping Xie
- The Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Wen-Hui Lin
- The Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; Shanghai Collaborative Innovation Center of Agri-Seeds/Joint Center for Single Cell Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
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15
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Sherlock ME, Baquero Galvis L, Vicens Q, Kieft JS, Jagannathan S. Principles, mechanisms, and biological implications of translation termination-reinitiation. RNA (NEW YORK, N.Y.) 2023; 29:865-884. [PMID: 37024263 PMCID: PMC10275272 DOI: 10.1261/rna.079375.122] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 03/28/2023] [Indexed: 06/11/2023]
Abstract
The gene expression pathway from DNA sequence to functional protein is not as straightforward as simple depictions of the central dogma might suggest. Each step is highly regulated, with complex and only partially understood molecular mechanisms at play. Translation is one step where the "one gene-one protein" paradigm breaks down, as often a single mature eukaryotic mRNA leads to more than one protein product. One way this occurs is through translation reinitiation, in which a ribosome starts making protein from one initiation site, translates until it terminates at a stop codon, but then escapes normal recycling steps and subsequently reinitiates at a different downstream site. This process is now recognized as both important and widespread, but we are only beginning to understand the interplay of factors involved in termination, recycling, and initiation that cause reinitiation events. There appear to be several ways to subvert recycling to achieve productive reinitiation, different types of stresses or signals that trigger this process, and the mechanism may depend in part on where the event occurs in the body of an mRNA. This perspective reviews the unique characteristics and mechanisms of reinitiation events, highlights the similarities and differences between three major scenarios of reinitiation, and raises outstanding questions that are promising avenues for future research.
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Affiliation(s)
- Madeline E Sherlock
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Laura Baquero Galvis
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Quentin Vicens
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Jeffrey S Kieft
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Sujatha Jagannathan
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
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16
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Ikeuchi K, Ivic N, Buschauer R, Cheng J, Fröhlich T, Matsuo Y, Berninghausen O, Inada T, Becker T, Beckmann R. Molecular basis for recognition and deubiquitination of 40S ribosomes by Otu2. Nat Commun 2023; 14:2730. [PMID: 37169754 PMCID: PMC10175282 DOI: 10.1038/s41467-023-38161-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 04/19/2023] [Indexed: 05/13/2023] Open
Abstract
In actively translating 80S ribosomes the ribosomal protein eS7 of the 40S subunit is monoubiquitinated by the E3 ligase Not4 and deubiquitinated by Otu2 upon ribosomal subunit recycling. Despite its importance for translation efficiency the exact role and structural basis for this translational reset is poorly understood. Here, structural analysis by cryo-electron microscopy of native and reconstituted Otu2-bound ribosomal complexes reveals that Otu2 engages 40S subunits mainly between ribosome recycling and initiation stages. Otu2 binds to several sites on the intersubunit surface of the 40S that are not occupied by any other 40S-binding factors. This binding mode explains the discrimination against 80S ribosomes via the largely helical N-terminal domain of Otu2 as well as the specificity for mono-ubiquitinated eS7 on 40S. Collectively, this study reveals mechanistic insights into the Otu2-driven deubiquitination steps for translational reset during ribosome recycling/(re)initiation.
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Affiliation(s)
- Ken Ikeuchi
- Department of Biochemistry, Gene Center, Feodor-Lynen-Str. 25, University of Munich, 81377, Munich, Germany
| | - Nives Ivic
- Division of Physical Chemistry, Rudjer Boskovic Institute, Bijenicka cesta 54, 10000, Zagreb, Croatia
| | - Robert Buschauer
- Department of Biochemistry, Gene Center, Feodor-Lynen-Str. 25, University of Munich, 81377, Munich, Germany
| | - Jingdong Cheng
- Department of Biochemistry, Gene Center, Feodor-Lynen-Str. 25, University of Munich, 81377, Munich, Germany
- Institutes of biomedical science, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Fudan university, Dong'an Road 131, 200032, Shanghai, China
| | - Thomas Fröhlich
- LAFUGA, Laboratory for Functional Genome Analysis, Gene Center, Feodor-Lynen-Str. 25, University of Munich, 81377, Munich, Germany
| | - Yoshitaka Matsuo
- Division of RNA and Gene Regulation, Institute of Medical Science, The University of Tokyo, Minato-ku, 108-8639, Japan
| | - Otto Berninghausen
- Department of Biochemistry, Gene Center, Feodor-Lynen-Str. 25, University of Munich, 81377, Munich, Germany
| | - Toshifumi Inada
- Division of RNA and Gene Regulation, Institute of Medical Science, The University of Tokyo, Minato-ku, 108-8639, Japan
| | - Thomas Becker
- Department of Biochemistry, Gene Center, Feodor-Lynen-Str. 25, University of Munich, 81377, Munich, Germany.
| | - Roland Beckmann
- Department of Biochemistry, Gene Center, Feodor-Lynen-Str. 25, University of Munich, 81377, Munich, Germany.
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17
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Reilly CR, Shimamura A. Predisposition to myeloid malignancies in Shwachman-Diamond syndrome: biological insights and clinical advances. Blood 2023; 141:1513-1523. [PMID: 36542827 PMCID: PMC10082379 DOI: 10.1182/blood.2022017739] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 12/08/2022] [Accepted: 12/12/2022] [Indexed: 12/24/2022] Open
Abstract
Shwachman-Diamond syndrome (SDS) is an inherited multisystem ribosomopathy characterized by exocrine pancreatic deficiency, bone marrow failure, and predisposition to myeloid malignancies. The pathobiology of SDS results from impaired ribosomal maturation due to the deficiency of SBDS and the inability to evict the antiassociation factor eIF6 from the 60S ribosomal subunit. Clinical outcomes for patients with SDS who develop myeloid malignancies are extremely poor because of high treatment-related toxicities and a high rate of refractory disease/relapse even after allogeneic hematopoietic stem cell transplant (HSCT). Registry data indicate that outcomes are improved for patients with SDS who undergo routine bone marrow surveillance and receive an HSCT before developing an overt malignancy. However, the optimal approach to hematologic surveillance and the timing of HSCT for patients with SDS is not clearly established. Recent studies have elucidated distinct patterns of somatic blood mutations in patients with SDS that either alleviate the ribosome defect via somatic rescue (heterozygous EIF6 inactivation) or disrupt cellular checkpoints, resulting in increased leukemogenic potential (heterozygous TP53 inactivation). Genomic analysis revealed that most myeloid malignancies in patients with SDS have biallelic loss-of-function TP53 mutations. Single-cell DNA sequencing of SDS bone marrow samples can detect premalignant biallelic TP53-mutated clones before clinical diagnosis, suggesting that molecular surveillance may enhance the detection of incipient myeloid malignancies when HSCT may be most effective. Here, we review the clinical, genetic, and biologic features of SDS. In addition, we present evidence supporting the hematologic surveillance for patients with SDS that incorporates clinical, pathologic, and molecular data to risk stratify patients and prioritize transplant evaluation for patients with SDS with high-risk features.
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Affiliation(s)
- Christopher R. Reilly
- Division of Hematological Malignancies, Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA
| | - Akiko Shimamura
- Department of Pediatric Hematology/Oncology, Dana-Farber/Boston Children’s Cancer and Blood Disorders Center, Boston, MA
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18
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Kobayashi S, Kaji A, Kaji H. A novel function for eukaryotic elongation factor 3: Inhibition of stop codon readthrough in yeast. Arch Biochem Biophys 2023; 740:109580. [PMID: 36948349 DOI: 10.1016/j.abb.2023.109580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 03/16/2023] [Accepted: 03/18/2023] [Indexed: 03/24/2023]
Abstract
Eukaryotic elongation factor 3 (eEF3) is one of the essential yeast ribosome-associated ATP-binding cassette type F (ABCF) ATPases. Previously, we found that eEF3 stimulates release of mRNA from puromycin-treated polysomes. In this study, we used a cell-free cricket paralysis virus (CrPV) internal ribosome entry site (IRES)-mediated firefly luciferase bicistronic mRNA translation system with yeast S30 extract. When eEF3 was partially removed from the crude extract, the product from the downstream ORF was increased by the readthrough of a UAA stop codon in the upstream ORF. eEF3 enhanced the release of luciferase from the polysome by eukaryotic release factor (eRF)1 and eRF3. These results suggest that eEF3 is a factor that assists eRFs in performing normal protein synthesis termination in yeast.
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Affiliation(s)
- Soushi Kobayashi
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, 3610 Hamilton Walk, Philadelphia, PA, 19104, USA; Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA, 19107, USA.
| | - Akira Kaji
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, 3610 Hamilton Walk, Philadelphia, PA, 19104, USA.
| | - Hideko Kaji
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA, 19107, USA
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19
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Fernandez SG, Ferguson L, Ingolia NT. Ribosome rescue factor PELOTA modulates translation start site choice and protein isoform levels of transcription factor C/EBP α. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.16.524343. [PMID: 36711859 PMCID: PMC9882168 DOI: 10.1101/2023.01.16.524343] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Translation initiation at alternative start sites can dynamically control the synthesis of two or more functionally distinct protein isoforms from a single mRNA. Alternate isoforms of the hematopoietic transcription factor CCAAT-enhancer binding protein α (C/EBPα) produced from different start sites exert opposing effects during myeloid cell development. This alternative initiation depends on sequence features of the CEBPA transcript, including a regulatory upstream open reading frame (uORF), but the molecular basis is not fully understood. Here we identify trans-acting factors that affect C/EBPα isoform choice using a sensitive and quantitative two-color fluorescence reporter coupled with CRISPRi screening. Our screen uncovered a role for the ribosome rescue factor PELOTA (PELO) in promoting expression of the longer C/EBPα isoform, by directly removing inhibitory unrecycled ribosomes and through indirect effects mediated by the mechanistic target of rapamycin (mTOR) kinase. Our work provides further mechanistic insights into coupling between ribosome recycling and translation reinitiation in regulation of a key transcription factor, with implications for normal hematopoiesis and leukemiagenesis.
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Affiliation(s)
| | - Lucas Ferguson
- Department of Molecular and Cell Biology, University of California, Berkeley
| | - Nicholas T. Ingolia
- Department of Molecular and Cell Biology, University of California, Berkeley
- Center for Computational Biology and California Institute for Quantitative Biosciences, University of California, Berkeley
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20
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Makeeva DS, Riggs CL, Burakov AV, Ivanov PA, Kushchenko AS, Bykov DA, Popenko VI, Prassolov VS, Ivanov PV, Dmitriev SE. Relocalization of Translation Termination and Ribosome Recycling Factors to Stress Granules Coincides with Elevated Stop-Codon Readthrough and Reinitiation Rates upon Oxidative Stress. Cells 2023; 12:259. [PMID: 36672194 PMCID: PMC9856671 DOI: 10.3390/cells12020259] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 12/27/2022] [Accepted: 01/03/2023] [Indexed: 01/11/2023] Open
Abstract
Upon oxidative stress, mammalian cells rapidly reprogram their translation. This is accompanied by the formation of stress granules (SGs), cytoplasmic ribonucleoprotein condensates containing untranslated mRNA molecules, RNA-binding proteins, 40S ribosomal subunits, and a set of translation initiation factors. Here we show that arsenite-induced stress causes a dramatic increase in the stop-codon readthrough rate and significantly elevates translation reinitiation levels on uORF-containing and bicistronic mRNAs. We also report the recruitment of translation termination factors eRF1 and eRF3, as well as ribosome recycling and translation reinitiation factors ABCE1, eIF2D, MCT-1, and DENR to SGs upon arsenite treatment. Localization of these factors to SGs may contribute to a rapid resumption of mRNA translation after stress relief and SG disassembly. It may also suggest the presence of post-termination, recycling, or reinitiation complexes in SGs. This new layer of translational control under stress conditions, relying on the altered spatial distribution of translation factors between cellular compartments, is discussed.
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Affiliation(s)
- Desislava S. Makeeva
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Claire L. Riggs
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Anton V. Burakov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Pavel A. Ivanov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Artem S. Kushchenko
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Dmitri A. Bykov
- Faculty of Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Vladimir I. Popenko
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Vladimir S. Prassolov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Pavel V. Ivanov
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Sergey E. Dmitriev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 119234 Moscow, Russia
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
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21
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Huang S, Bhattacharya A, Ghelfi MD, Li H, Fritsch C, Chenoweth DM, Goldman YE, Cooperman BS. Ataluren binds to multiple protein synthesis apparatus sites and competitively inhibits release factor-dependent termination. Nat Commun 2022; 13:2413. [PMID: 35523781 PMCID: PMC9076611 DOI: 10.1038/s41467-022-30080-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 04/12/2022] [Indexed: 12/15/2022] Open
Abstract
Genetic diseases are often caused by nonsense mutations, but only one TRID (translation readthrough inducing drug), ataluren, has been approved for clinical use. Ataluren inhibits release factor complex (RFC) termination activity, while not affecting productive binding of near-cognate ternary complex (TC, aa-tRNA.eEF1A.GTP). Here we use photoaffinity labeling to identify two sites of ataluren binding within rRNA, proximal to the decoding center (DC) and the peptidyl transfer center (PTC) of the ribosome, which are directly responsible for ataluren inhibition of termination activity. A third site, within the RFC, has as yet unclear functional consequences. Using single molecule and ensemble fluorescence assays we also demonstrate that termination proceeds via rapid RFC-dependent hydrolysis of peptidyl-tRNA followed by slow release of peptide and tRNA from the ribosome. Ataluren is an apparent competitive inhibitor of productive RFC binding, acting at or before the hydrolysis step. We propose that designing more potent TRIDs which retain ataluren's low toxicity should target areas of the RFC binding site proximal to the DC and PTC which do not overlap the TC binding site.
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Affiliation(s)
- Shijie Huang
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA
- GSK, 14200 Shady Grove Rd, Rockville, MD, 20850, USA
| | - Arpan Bhattacharya
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Mikel D Ghelfi
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Hong Li
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Clark Fritsch
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - David M Chenoweth
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Yale E Goldman
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Barry S Cooperman
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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22
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Filbeck S, Cerullo F, Pfeffer S, Joazeiro CAP. Ribosome-associated quality-control mechanisms from bacteria to humans. Mol Cell 2022; 82:1451-1466. [PMID: 35452614 PMCID: PMC9034055 DOI: 10.1016/j.molcel.2022.03.038] [Citation(s) in RCA: 61] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 03/23/2022] [Accepted: 03/28/2022] [Indexed: 11/16/2022]
Abstract
Ribosome-associated quality-control (RQC) surveys incomplete nascent polypeptides produced by interrupted translation. Central players in RQC are the human ribosome- and tRNA-binding protein, NEMF, and its orthologs, yeast Rqc2 and bacterial RqcH, which sense large ribosomal subunits obstructed with nascent chains and then promote nascent-chain proteolysis. In canonical eukaryotic RQC, NEMF stabilizes the LTN1/Listerin E3 ligase binding to obstructed ribosomal subunits for nascent-chain ubiquitylation. Furthermore, NEMF orthologs across evolution modify nascent chains by mediating C-terminal, untemplated polypeptide elongation. In eukaryotes, this process exposes ribosome-buried nascent-chain lysines, the ubiquitin acceptor sites, to LTN1. Remarkably, in both bacteria and eukaryotes, C-terminal tails also have an extra-ribosomal function as degrons. Here, we discuss recent findings on RQC mechanisms and briefly review how ribosomal stalling is sensed upstream of RQC, including via ribosome collisions, from an evolutionary perspective. Because RQC defects impair cellular fitness and cause neurodegeneration, this knowledge provides a framework for pathway-related biology and disease studies.
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Affiliation(s)
- Sebastian Filbeck
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
| | - Federico Cerullo
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
| | - Stefan Pfeffer
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany.
| | - Claudio A P Joazeiro
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany; Department of Molecular Medicine, Scripps Florida, Jupiter, FL 33458, USA.
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23
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Zhouravleva GA, Bondarev SA, Zemlyanko OM, Moskalenko SE. Role of Proteins Interacting with the eRF1 and eRF3 Release Factors in the Regulation of Translation and Prionization. Mol Biol 2022. [DOI: 10.1134/s0026893322010101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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24
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Jaako P, Faille A, Tan S, Wong CC, Escudero-Urquijo N, Castro-Hartmann P, Wright P, Hilcenko C, Adams DJ, Warren AJ. eIF6 rebinding dynamically couples ribosome maturation and translation. Nat Commun 2022; 13:1562. [PMID: 35322020 PMCID: PMC8943182 DOI: 10.1038/s41467-022-29214-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 03/03/2022] [Indexed: 02/05/2023] Open
Abstract
Protein synthesis is a cyclical process consisting of translation initiation, elongation, termination and ribosome recycling. The release factors SBDS and EFL1—both mutated in the leukemia predisposition disorder Shwachman-Diamond syndrome — license entry of nascent 60S ribosomal subunits into active translation by evicting the anti-association factor eIF6 from the 60S intersubunit face. We find that in mammalian cells, eIF6 holds all free cytoplasmic 60S subunits in a translationally inactive state and that SBDS and EFL1 are the minimal components required to recycle these 60S subunits back into additional rounds of translation by evicting eIF6. Increasing the dose of eIF6 in mice in vivo impairs terminal erythropoiesis by sequestering post-termination 60S subunits in the cytoplasm, disrupting subunit joining and attenuating global protein synthesis. These data reveal that ribosome maturation and recycling are dynamically coupled by a mechanism that is disrupted in an inherited leukemia predisposition disorder. Jaako et al. discover a conserved tier of translational control that dynamically couples ribosome assembly and recycling. This mechanism is corrupted in an inherited bone marrow failure disorder associated with an increased risk of blood cancer.
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Affiliation(s)
- Pekka Jaako
- Cambridge Institute for Medical Research, Cambridge Biomedical Campus, Keith Peters Building, Hills Rd, Cambridge, CB2 0XY, UK.,Wellcome Trust-Medical Research Council Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge Biomedical Campus, Cambridge, CB2 0AW, UK.,Department of Haematology, University of Cambridge School of Clinical Medicine, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge Biomedical Campus, Cambridge, CB2 0AW, UK.,Sahlgrenska Center for Cancer Research, Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, 413 90, Gothenburg, Sweden
| | - Alexandre Faille
- Cambridge Institute for Medical Research, Cambridge Biomedical Campus, Keith Peters Building, Hills Rd, Cambridge, CB2 0XY, UK.,Wellcome Trust-Medical Research Council Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge Biomedical Campus, Cambridge, CB2 0AW, UK.,Department of Haematology, University of Cambridge School of Clinical Medicine, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge Biomedical Campus, Cambridge, CB2 0AW, UK
| | - Shengjiang Tan
- Cambridge Institute for Medical Research, Cambridge Biomedical Campus, Keith Peters Building, Hills Rd, Cambridge, CB2 0XY, UK.,Wellcome Trust-Medical Research Council Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge Biomedical Campus, Cambridge, CB2 0AW, UK.,Department of Haematology, University of Cambridge School of Clinical Medicine, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge Biomedical Campus, Cambridge, CB2 0AW, UK
| | - Chi C Wong
- Cambridge Institute for Medical Research, Cambridge Biomedical Campus, Keith Peters Building, Hills Rd, Cambridge, CB2 0XY, UK.,Department of Pathology, Cambridge University Hospitals, Hills Road, Cambridge, CB2 0QQ, UK
| | - Norberto Escudero-Urquijo
- Cambridge Institute for Medical Research, Cambridge Biomedical Campus, Keith Peters Building, Hills Rd, Cambridge, CB2 0XY, UK.,Wellcome Trust-Medical Research Council Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge Biomedical Campus, Cambridge, CB2 0AW, UK.,Department of Haematology, University of Cambridge School of Clinical Medicine, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge Biomedical Campus, Cambridge, CB2 0AW, UK
| | - Pablo Castro-Hartmann
- Cambridge Institute for Medical Research, Cambridge Biomedical Campus, Keith Peters Building, Hills Rd, Cambridge, CB2 0XY, UK.,Wellcome Trust-Medical Research Council Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge Biomedical Campus, Cambridge, CB2 0AW, UK.,Department of Haematology, University of Cambridge School of Clinical Medicine, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge Biomedical Campus, Cambridge, CB2 0AW, UK
| | - Penny Wright
- Department of Pathology, Cambridge University Hospitals, Hills Road, Cambridge, CB2 0QQ, UK
| | - Christine Hilcenko
- Cambridge Institute for Medical Research, Cambridge Biomedical Campus, Keith Peters Building, Hills Rd, Cambridge, CB2 0XY, UK.,Wellcome Trust-Medical Research Council Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge Biomedical Campus, Cambridge, CB2 0AW, UK.,Department of Haematology, University of Cambridge School of Clinical Medicine, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge Biomedical Campus, Cambridge, CB2 0AW, UK
| | - David J Adams
- Experimental Cancer Genetics, Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
| | - Alan J Warren
- Cambridge Institute for Medical Research, Cambridge Biomedical Campus, Keith Peters Building, Hills Rd, Cambridge, CB2 0XY, UK. .,Wellcome Trust-Medical Research Council Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge Biomedical Campus, Cambridge, CB2 0AW, UK. .,Department of Haematology, University of Cambridge School of Clinical Medicine, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge Biomedical Campus, Cambridge, CB2 0AW, UK.
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25
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Young DJ, Guydosh NR. Rebirth of the translational machinery: The importance of recycling ribosomes. Bioessays 2022; 44:e2100269. [PMID: 35147231 PMCID: PMC9270684 DOI: 10.1002/bies.202100269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 01/26/2022] [Accepted: 01/27/2022] [Indexed: 11/10/2022]
Abstract
Translation of the genetic code occurs in a cycle where ribosomes engage mRNAs, synthesize protein, and then disengage in order to repeat the process again. The final part of this process-ribosome recycling, where ribosomes dissociate from mRNAs-involves a complex molecular choreography of specific protein factors to remove the large and small subunits of the ribosome in a coordinated fashion. Errors in this process can lead to the accumulation of ribosomes at stop codons or translation of downstream open reading frames (ORFs). Ribosome recycling is also critical when a ribosome stalls during the elongation phase of translation and must be rescued to allow continued translation of the mRNA. Here we discuss the molecular interactions that drive ribosome recycling, and their regulation in the cell. We also examine the consequences of inefficient recycling with regards to disease, and its functional roles in synthesis of novel peptides, regulation of gene expression, and control of mRNA-associated proteins. Alterations in ribosome recycling efficiency have the potential to impact many cellular functions but additional work is needed to understand how this regulatory power is utilized.
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Affiliation(s)
- David J Young
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Nicholas R Guydosh
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
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26
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Blanchet S, Ranjan N. In Vitro Assembly of a Fully Reconstituted Yeast Translation System for Studies of Initiation and Elongation Phases of Protein Synthesis. Methods Mol Biol 2022; 2533:259-280. [PMID: 35796994 PMCID: PMC9761531 DOI: 10.1007/978-1-0716-2501-9_16] [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] [Indexed: 06/15/2023]
Abstract
Protein synthesis is an essential and highly regulated cellular process. To facilitate the understanding of eukaryotic translation, we have assembled an in vitro translation system from yeast using purified components to recapitulate the initiation and elongation phases of protein synthesis. Here, we describe methods to express and purify the components of the translation system and the assays for their functional characterization.
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Affiliation(s)
- Sandra Blanchet
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Goettingen, Germany
| | - Namit Ranjan
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Goettingen, Germany.
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27
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Blanchet S, Ranjan N. Translation Phases in Eukaryotes. Methods Mol Biol 2022; 2533:217-228. [PMID: 35796991 PMCID: PMC9761538 DOI: 10.1007/978-1-0716-2501-9_13] [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] [Indexed: 06/15/2023]
Abstract
Protein synthesis in eukaryotes is carried out by 80S ribosomes with the help of many specific translation factors. Translation comprises four major steps: initiation, elongation, termination, and ribosome recycling. In this review, we provide a comprehensive list of translation factors required for protein synthesis in yeast and higher eukaryotes and summarize the mechanisms of each individual phase of eukaryotic translation.
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Affiliation(s)
- Sandra Blanchet
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Goettingen, Germany
| | - Namit Ranjan
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Goettingen, Germany.
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28
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Karki P, Carney TD, Maracci C, Yatsenko AS, Shcherbata HR, Rodnina MV. Tissue-specific regulation of translational readthrough tunes functions of the traffic jam transcription factor. Nucleic Acids Res 2021; 50:6001-6019. [PMID: 34897510 PMCID: PMC9226519 DOI: 10.1093/nar/gkab1189] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 11/05/2021] [Accepted: 12/06/2021] [Indexed: 11/13/2022] Open
Abstract
Translational readthrough (TR) occurs when the ribosome decodes a stop codon as a sense codon, resulting in two protein isoforms synthesized from the same mRNA. TR has been identified in several eukaryotic organisms; however, its biological significance and mechanism remain unclear. Here, we quantify TR of several candidate genes in Drosophila melanogaster and characterize the regulation of TR in the large Maf transcription factor Traffic jam (Tj). Using CRISPR/Cas9-generated mutant flies, we show that the TR-generated Tj isoform is expressed in a subset of neural cells of the central nervous system and is excluded from the somatic cells of gonads. Control of TR in Tj is critical for preservation of neuronal integrity and maintenance of reproductive health. The tissue-specific distribution of a release factor splice variant, eRF1H, plays a critical role in modulating differential TR of leaky stop codon contexts. Fine-tuning of gene regulatory functions of transcription factors by TR provides a potential mechanism for cell-specific regulation of gene expression.
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Affiliation(s)
- Prajwal Karki
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, 37077 Goettingen, Germany
| | - Travis D Carney
- Gene Expression and Signaling Group, Institute of Cell Biochemistry, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Cristina Maracci
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, 37077 Goettingen, Germany
| | - Andriy S Yatsenko
- Gene Expression and Signaling Group, Institute of Cell Biochemistry, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Halyna R Shcherbata
- Gene Expression and Signaling Group, Institute of Cell Biochemistry, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Marina V Rodnina
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, 37077 Goettingen, Germany
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29
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Egorova T, Biziaev N, Shuvalov A, Sokolova E, Mukba S, Evmenov K, Zotova M, Kushchenko A, Shuvalova E, Alkalaeva E. eIF3j facilitates loading of release factors into the ribosome. Nucleic Acids Res 2021; 49:11181-11196. [PMID: 34591963 PMCID: PMC8565342 DOI: 10.1093/nar/gkab854] [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: 05/30/2021] [Revised: 08/23/2021] [Accepted: 09/14/2021] [Indexed: 12/14/2022] Open
Abstract
eIF3j is one of the eukaryotic translation factors originally reported as the labile subunit of the eukaryotic translation initiation factor eIF3. The yeast homolog of this protein, Hcr1, has been implicated in stringent AUG recognition as well as in controlling translation termination and stop codon readthrough. Using a reconstituted mammalian in vitro translation system, we showed that the human protein eIF3j is also important for translation termination. We showed that eIF3j stimulates peptidyl-tRNA hydrolysis induced by a complex of eukaryotic release factors, eRF1-eRF3. Moreover, in combination with the initiation factor eIF3, which also stimulates peptide release, eIF3j activity in translation termination increases. We found that eIF3j interacts with the pre-termination ribosomal complex, and eRF3 destabilises this interaction. In the solution, these proteins bind to each other and to other participants of translation termination, eRF1 and PABP, in the presence of GTP. Using a toe-printing assay, we determined the stage at which eIF3j functions – binding of release factors to the A-site of the ribosome before GTP hydrolysis. Based on these data, we assumed that human eIF3j is involved in the regulation of translation termination by loading release factors into the ribosome.
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Affiliation(s)
- Tatiana Egorova
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia.,Center for Precision Genome Editing and Genetic Technologies for Biomedicine, 119991 Moscow, Russia
| | - Nikita Biziaev
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia
| | - Alexey Shuvalov
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia.,Center for Precision Genome Editing and Genetic Technologies for Biomedicine, 119991 Moscow, Russia
| | - Elizaveta Sokolova
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia.,Center for Precision Genome Editing and Genetic Technologies for Biomedicine, 119991 Moscow, Russia
| | - Sabina Mukba
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia
| | - Konstantin Evmenov
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia
| | - Maria Zotova
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia
| | - Artem Kushchenko
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia
| | - Ekaterina Shuvalova
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia
| | - Elena Alkalaeva
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia.,Center for Precision Genome Editing and Genetic Technologies for Biomedicine, 119991 Moscow, Russia
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30
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Zinshteyn B, Sinha NK, Enam SU, Koleske B, Green R. Translational repression of NMD targets by GIGYF2 and EIF4E2. PLoS Genet 2021; 17:e1009813. [PMID: 34665823 PMCID: PMC8555832 DOI: 10.1371/journal.pgen.1009813] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 10/29/2021] [Accepted: 09/08/2021] [Indexed: 12/26/2022] Open
Abstract
Translation of messenger RNAs (mRNAs) with premature termination codons produces truncated proteins with potentially deleterious effects. This is prevented by nonsense-mediated mRNA decay (NMD) of these mRNAs. NMD is triggered by ribosomes terminating upstream of a splice site marked by an exon-junction complex (EJC), but also acts on many mRNAs lacking a splice junction after their termination codon. We developed a genome-wide CRISPR flow cytometry screen to identify regulators of mRNAs with premature termination codons in K562 cells. This screen recovered essentially all core NMD factors and suggested a role for EJC factors in degradation of PTCs without downstream splicing. Among the strongest hits were the translational repressors GIGYF2 and EIF4E2. GIGYF2 and EIF4E2 mediate translational repression but not mRNA decay of a subset of NMD targets and interact with NMD factors genetically and physically. Our results suggest a model wherein recognition of a stop codon as premature can lead to its translational repression through GIGYF2 and EIF4E2.
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Affiliation(s)
- Boris Zinshteyn
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Niladri K. Sinha
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Syed Usman Enam
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Benjamin Koleske
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Rachel Green
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
- * E-mail:
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31
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Lawson MR, Lessen LN, Wang J, Prabhakar A, Corsepius NC, Green R, Puglisi JD. Mechanisms that ensure speed and fidelity in eukaryotic translation termination. Science 2021; 373:876-882. [PMID: 34413231 PMCID: PMC9017434 DOI: 10.1126/science.abi7801] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 07/07/2021] [Indexed: 11/02/2022]
Abstract
Translation termination, which liberates a nascent polypeptide from the ribosome specifically at stop codons, must occur accurately and rapidly. We established single-molecule fluorescence assays to track the dynamics of ribosomes and two requisite release factors (eRF1 and eRF3) throughout termination using an in vitro-reconstituted yeast translation system. We found that the two eukaryotic release factors bound together to recognize stop codons rapidly and elicit termination through a tightly regulated, multistep process that resembles transfer RNA selection during translation elongation. Because the release factors are conserved from yeast to humans, the molecular events that underlie yeast translation termination are likely broadly fundamental to eukaryotic protein synthesis.
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Affiliation(s)
- Michael R Lawson
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Laura N Lessen
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
- Program in Molecular Biophysics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jinfan Wang
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Arjun Prabhakar
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Nicholas C Corsepius
- Program in Molecular Biophysics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Rachel Green
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA.
- Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Joseph D Puglisi
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA.
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32
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Padmanabhan PK, Ferreira GR, Zghidi-Abouzid O, Oliveira C, Dumas C, Mariz FC, Papadopoulou B. Genetic depletion of the RNA helicase DDX3 leads to impaired elongation of translating ribosomes triggering co-translational quality control of newly synthesized polypeptides. Nucleic Acids Res 2021; 49:9459-9478. [PMID: 34358325 PMCID: PMC8450092 DOI: 10.1093/nar/gkab667] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 07/15/2021] [Accepted: 07/23/2021] [Indexed: 11/29/2022] Open
Abstract
DDX3 is a multifaceted RNA helicase of the DEAD-box family that plays central roles in all aspects of RNA metabolism including translation initiation. Here, we provide evidence that the Leishmania DDX3 ortholog functions in post-initiation steps of translation. We show that genetic depletion of DDX3 slows down ribosome movement resulting in elongation-stalled ribosomes, impaired translation elongation and decreased de novo protein synthesis. We also demonstrate that the essential ribosome recycling factor Rli1/ABCE1 and termination factors eRF3 and GTPBP1 are less recruited to ribosomes upon DDX3 loss, suggesting that arrested ribosomes may be inefficiently dissociated and recycled. Furthermore, we show that prolonged ribosome stalling triggers co-translational ubiquitination of nascent polypeptide chains and a higher recruitment of E3 ubiquitin ligases and proteasome components to ribosomes of DDX3 knockout cells, which further supports that ribosomes are not elongating optimally. Impaired elongation of translating ribosomes also results in the accumulation of cytoplasmic protein aggregates, which implies that defects in translation overwhelm the normal quality controls. The partial recovery of translation by overexpressing Hsp70 supports this possibility. Collectively, these results suggest an important novel contribution of DDX3 to optimal elongation of translating ribosomes by preventing prolonged translation stalls and stimulating recycling of arrested ribosomes.
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Affiliation(s)
- Prasad Kottayil Padmanabhan
- Research Center in Infectious Diseases, Division of Infectious Disease and Immunity CHU de Quebec Research Center-University Laval, Quebec, QC G1V 4G2, Canada.,Department of Microbiology, Infectious Disease and Immunology, Faculty of Medicine, University Laval, Quebec, QC G1V 4G2, Canada
| | - Gabriel Reis Ferreira
- Research Center in Infectious Diseases, Division of Infectious Disease and Immunity CHU de Quebec Research Center-University Laval, Quebec, QC G1V 4G2, Canada.,Department of Microbiology, Infectious Disease and Immunology, Faculty of Medicine, University Laval, Quebec, QC G1V 4G2, Canada
| | - Ouafa Zghidi-Abouzid
- Research Center in Infectious Diseases, Division of Infectious Disease and Immunity CHU de Quebec Research Center-University Laval, Quebec, QC G1V 4G2, Canada.,Department of Microbiology, Infectious Disease and Immunology, Faculty of Medicine, University Laval, Quebec, QC G1V 4G2, Canada
| | - Camila Oliveira
- Research Center in Infectious Diseases, Division of Infectious Disease and Immunity CHU de Quebec Research Center-University Laval, Quebec, QC G1V 4G2, Canada.,Department of Microbiology, Infectious Disease and Immunology, Faculty of Medicine, University Laval, Quebec, QC G1V 4G2, Canada
| | - Carole Dumas
- Research Center in Infectious Diseases, Division of Infectious Disease and Immunity CHU de Quebec Research Center-University Laval, Quebec, QC G1V 4G2, Canada.,Department of Microbiology, Infectious Disease and Immunology, Faculty of Medicine, University Laval, Quebec, QC G1V 4G2, Canada
| | - Filipe Colaço Mariz
- Research Center in Infectious Diseases, Division of Infectious Disease and Immunity CHU de Quebec Research Center-University Laval, Quebec, QC G1V 4G2, Canada.,Department of Microbiology, Infectious Disease and Immunology, Faculty of Medicine, University Laval, Quebec, QC G1V 4G2, Canada
| | - Barbara Papadopoulou
- Research Center in Infectious Diseases, Division of Infectious Disease and Immunity CHU de Quebec Research Center-University Laval, Quebec, QC G1V 4G2, Canada.,Department of Microbiology, Infectious Disease and Immunology, Faculty of Medicine, University Laval, Quebec, QC G1V 4G2, Canada
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33
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Takada H, Crowe-McAuliffe C, Polte C, Sidorova ZY, Murina V, Atkinson GC, Konevega AL, Ignatova Z, Wilson DN, Hauryliuk V. RqcH and RqcP catalyze processive poly-alanine synthesis in a reconstituted ribosome-associated quality control system. Nucleic Acids Res 2021; 49:8355-8369. [PMID: 34255840 PMCID: PMC8373112 DOI: 10.1093/nar/gkab589] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/21/2021] [Accepted: 06/24/2021] [Indexed: 01/13/2023] Open
Abstract
In the cell, stalled ribosomes are rescued through ribosome-associated protein quality-control (RQC) pathways. After splitting of the stalled ribosome, a C-terminal polyalanine 'tail' is added to the unfinished polypeptide attached to the tRNA on the 50S ribosomal subunit. In Bacillus subtilis, polyalanine tailing is catalyzed by the NEMF family protein RqcH, in cooperation with RqcP. However, the mechanistic details of this process remain unclear. Here we demonstrate that RqcH is responsible for tRNAAla selection during RQC elongation, whereas RqcP lacks any tRNA specificity. The ribosomal protein uL11 is crucial for RqcH, but not RqcP, recruitment to the 50S subunit, and B. subtilis lacking uL11 are RQC-deficient. Through mutational mapping, we identify critical residues within RqcH and RqcP that are important for interaction with the P-site tRNA and/or the 50S subunit. Additionally, we have reconstituted polyalanine-tailing in vitro and can demonstrate that RqcH and RqcP are necessary and sufficient for processivity in a minimal system. Moreover, the in vitro reconstituted system recapitulates our in vivo findings by reproducing the importance of conserved residues of RqcH and RqcP for functionality. Collectively, our findings provide mechanistic insight into the role of RqcH and RqcP in the bacterial RQC pathway.
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Affiliation(s)
- Hiraku Takada
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo, Motoyama, Kita-ku, Kyoto 603-8555, Japan.,Department of Molecular Biology, Umeå University, 90187 Umeå, Sweden.,Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, 90187 Umeå, Sweden
| | - Caillan Crowe-McAuliffe
- Institute for Biochemistry and Molecular Biology, University of Hamburg, 20146 Hamburg, Germany
| | - Christine Polte
- Institute for Biochemistry and Molecular Biology, University of Hamburg, 20146 Hamburg, Germany
| | - Zhanna Yu Sidorova
- Petersburg Nuclear Physics Institute named by B.P. Konstantinov of National Research Centre "Kurchatov Institute", 188300 Gatchina, Russia.,Russian Research Institute of Hematology and Transfusiology of FMBA, 191024 Saint Petersburg, Russia
| | - Victoriia Murina
- Department of Molecular Biology, Umeå University, 90187 Umeå, Sweden.,Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, 90187 Umeå, Sweden
| | - Gemma C Atkinson
- National Research Centre "Kurchatov Institute", 123182 Moscow, Russia
| | - Andrey L Konevega
- Petersburg Nuclear Physics Institute named by B.P. Konstantinov of National Research Centre "Kurchatov Institute", 188300 Gatchina, Russia.,Peter the Great St. Petersburg Polytechnic University, 195251 Saint Petersburg, Russia.,National Research Centre "Kurchatov Institute", 123182 Moscow, Russia
| | - Zoya Ignatova
- Institute for Biochemistry and Molecular Biology, University of Hamburg, 20146 Hamburg, Germany
| | - Daniel N Wilson
- Institute for Biochemistry and Molecular Biology, University of Hamburg, 20146 Hamburg, Germany
| | - Vasili Hauryliuk
- Department of Molecular Biology, Umeå University, 90187 Umeå, Sweden.,Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, 90187 Umeå, Sweden.,Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden.,University of Tartu, Institute of Technology, 50411 Tartu, Estonia
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34
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Howard CJ, Frost A. Ribosome-associated quality control and CAT tailing. Crit Rev Biochem Mol Biol 2021; 56:603-620. [PMID: 34233554 DOI: 10.1080/10409238.2021.1938507] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Translation is the set of mechanisms by which ribosomes decode genetic messages as they synthesize polypeptides of a defined amino acid sequence. While the ribosome has been honed by evolution for high-fidelity translation, errors are inevitable. Aberrant mRNAs, mRNA structure, defective ribosomes, interactions between nascent proteins and the ribosomal exit tunnel, and insufficient cellular resources, including low tRNA levels, can lead to functionally irreversible stalls. Life thus depends on quality control mechanisms that detect, disassemble and recycle stalled translation intermediates. Ribosome-associated Quality Control (RQC) recognizes aberrant ribosome states and targets their potentially toxic polypeptides for degradation. Here we review recent advances in our understanding of RQC in bacteria, fungi, and metazoans. We focus in particular on an unusual modification made to the nascent chain known as a "CAT tail", or Carboxy-terminal Alanine and Threonine tail, and the mechanisms by which ancient RQC proteins catalyze CAT-tail synthesis.
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Affiliation(s)
- Conor J Howard
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, USA
| | - Adam Frost
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, USA
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35
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In Vitro Reconstitution of Yeast Translation System Capable of Synthesizing Long Polypeptide and Recapitulating Programmed Ribosome Stalling. Methods Protoc 2021; 4:mps4030045. [PMID: 34287320 PMCID: PMC8293373 DOI: 10.3390/mps4030045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/19/2021] [Accepted: 06/24/2021] [Indexed: 12/27/2022] Open
Abstract
The rates of translation elongation or termination in eukaryotes are modulated through cooperative molecular interactions involving mRNA, the ribosome, aminoacyl- and nascent polypeptidyl-tRNAs, and translation factors. To investigate the molecular mechanisms underlying these processes, we developed an in vitro translation system from yeast, reconstituted with purified translation elongation and termination factors, utilizing CrPV IGR IRES-containing mRNA, which functions in the absence of initiation factors. The system is capable of synthesizing not only short oligopeptides but also long reporter proteins such as nanoluciferase. By setting appropriate translation reaction conditions, such as the Mg2+/polyamine concentration, the arrest of translation elongation by known ribosome-stalling sequences (e.g., polyproline and CGA codon repeats) is properly recapitulated in this system. We describe protocols for the preparation of the system components, manipulation of the system, and detection of the translation products. We also mention critical parameters for setting up the translation reaction conditions. This reconstituted translation system not only facilitates biochemical analyses of translation but is also useful for various applications, such as structural and functional studies with the aim of designing drugs that act on eukaryotic ribosomes, and the development of systems for producing novel functional proteins by incorporating unnatural amino acids by eukaryotic ribosomes.
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36
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Lill R. From the discovery to molecular understanding of cellular iron-sulfur protein biogenesis. Biol Chem 2021; 401:855-876. [PMID: 32229650 DOI: 10.1515/hsz-2020-0117] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 03/10/2020] [Indexed: 12/23/2022]
Abstract
Protein cofactors often are the business ends of proteins, and are either synthesized inside cells or are taken up from the nutrition. A cofactor that strictly needs to be synthesized by cells is the iron-sulfur (Fe/S) cluster. This evolutionary ancient compound performs numerous biochemical functions including electron transfer, catalysis, sulfur mobilization, regulation and protein stabilization. Since the discovery of eukaryotic Fe/S protein biogenesis two decades ago, more than 30 biogenesis factors have been identified in mitochondria and cytosol. They support the synthesis, trafficking and target-specific insertion of Fe/S clusters. In this review, I first summarize what led to the initial discovery of Fe/S protein biogenesis in yeast. I then discuss the function and localization of Fe/S proteins in (non-green) eukaryotes. The major part of the review provides a detailed synopsis of the three major steps of mitochondrial Fe/S protein biogenesis, i.e. the de novo synthesis of a [2Fe-2S] cluster on a scaffold protein, the Hsp70 chaperone-mediated transfer of the cluster and integration into [2Fe-2S] recipient apoproteins, and the reductive fusion of [2Fe-2S] to [4Fe-4S] clusters and their subsequent assembly into target apoproteins. Finally, I summarize the current knowledge of the mechanisms underlying the maturation of cytosolic and nuclear Fe/S proteins.
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Affiliation(s)
- Roland Lill
- Institut für Zytobiologie, Philipps-Universität Marburg, Robert-Koch-Str. 6, D-35032 Marburg, Germany.,SYNMIKRO Center for Synthetic Microbiology, Philipps-Universität Marburg, Hans-Meerwein-Str., D-35043 Marburg, Germany
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37
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Impact of Hydrogen Peroxide on Protein Synthesis in Yeast. Antioxidants (Basel) 2021; 10:antiox10060952. [PMID: 34204720 PMCID: PMC8231629 DOI: 10.3390/antiox10060952] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 06/09/2021] [Accepted: 06/10/2021] [Indexed: 01/03/2023] Open
Abstract
Cells must be able to respond and adapt to different stress conditions to maintain normal function. A common response to stress is the global inhibition of protein synthesis. Protein synthesis is an expensive process consuming much of the cell's energy. Consequently, it must be tightly regulated to conserve resources. One of these stress conditions is oxidative stress, resulting from the accumulation of reactive oxygen species (ROS) mainly produced by the mitochondria but also by other intracellular sources. Cells utilize a variety of antioxidant systems to protect against ROS, directing signaling and adaptation responses at lower levels and/or detoxification as levels increase to preclude the accumulation of damage. In this review, we focus on the role of hydrogen peroxide, H2O2, as a signaling molecule regulating protein synthesis at different levels, including transcription and various parts of the translation process, e.g., initiation, elongation, termination and ribosome recycling.
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38
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Young DJ, Meydan S, Guydosh NR. 40S ribosome profiling reveals distinct roles for Tma20/Tma22 (MCT-1/DENR) and Tma64 (eIF2D) in 40S subunit recycling. Nat Commun 2021; 12:2976. [PMID: 34016977 PMCID: PMC8137927 DOI: 10.1038/s41467-021-23223-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 04/14/2021] [Indexed: 12/21/2022] Open
Abstract
The recycling of ribosomes at stop codons for use in further rounds of translation is critical for efficient protein synthesis. Removal of the 60S subunit is catalyzed by the ATPase Rli1 (ABCE1) while removal of the 40S is thought to require Tma64 (eIF2D), Tma20 (MCT-1), and Tma22 (DENR). However, it remains unclear how these Tma proteins cause 40S removal and control reinitiation of downstream translation. Here we used a 40S ribosome footprinting strategy to directly observe intermediate steps of ribosome recycling in cells. Deletion of the genes encoding these Tma proteins resulted in broad accumulation of unrecycled 40S subunits at stop codons, directly establishing their role in 40S recycling. Furthermore, the Tma20/Tma22 heterodimer was responsible for a majority of 40S recycling events while Tma64 played a minor role. Introduction of an autism-associated mutation into TMA22 resulted in a loss of 40S recycling activity, linking ribosome recycling and neurological disease.
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Affiliation(s)
- David J Young
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Sezen Meydan
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
- Postdoctoral Research Associate Training Program, National Institute of General Medical Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Nicholas R Guydosh
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.
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39
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Iron in Translation: From the Beginning to the End. Microorganisms 2021; 9:microorganisms9051058. [PMID: 34068342 PMCID: PMC8153317 DOI: 10.3390/microorganisms9051058] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 05/10/2021] [Accepted: 05/11/2021] [Indexed: 12/16/2022] Open
Abstract
Iron is an essential element for all eukaryotes, since it acts as a cofactor for many enzymes involved in basic cellular functions, including translation. While the mammalian iron-regulatory protein/iron-responsive element (IRP/IRE) system arose as one of the first examples of translational regulation in higher eukaryotes, little is known about the contribution of iron itself to the different stages of eukaryotic translation. In the yeast Saccharomyces cerevisiae, iron deficiency provokes a global impairment of translation at the initiation step, which is mediated by the Gcn2-eIF2α pathway, while the post-transcriptional regulator Cth2 specifically represses the translation of a subgroup of iron-related transcripts. In addition, several steps of the translation process depend on iron-containing enzymes, including particular modifications of translation elongation factors and transfer RNAs (tRNAs), and translation termination by the ATP-binding cassette family member Rli1 (ABCE1 in humans) and the prolyl hydroxylase Tpa1. The influence of these modifications and their correlation with codon bias in the dynamic control of protein biosynthesis, mainly in response to stress, is emerging as an interesting focus of research. Taking S. cerevisiae as a model, we hereby discuss the relevance of iron in the control of global and specific translation steps.
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40
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Terrey M, Adamson SI, Chuang JH, Ackerman SL. Defects in translation-dependent quality control pathways lead to convergent molecular and neurodevelopmental pathology. eLife 2021; 10:e66904. [PMID: 33899734 PMCID: PMC8075583 DOI: 10.7554/elife.66904] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/05/2021] [Indexed: 12/27/2022] Open
Abstract
Translation-dependent quality control pathways such as no-go decay (NGD), non-stop decay (NSD), and nonsense-mediated decay (NMD) govern protein synthesis and proteostasis by resolving non-translating ribosomes and preventing the production of potentially toxic peptides derived from faulty and aberrant mRNAs. However, how translation is altered and the in vivo defects that arise in the absence of these pathways are poorly understood. Here, we show that the NGD/NSD factors Pelo and Hbs1l are critical in mice for cerebellar neurogenesis but expendable for survival of these neurons after development. Analysis of mutant mouse embryonic fibroblasts revealed translational pauses, alteration of signaling pathways, and translational reprogramming. Similar effects on signaling pathways, including mTOR activation, the translatome and mouse cerebellar development were observed upon deletion of the NMD factor Upf2. Our data reveal that these quality control pathways that function to mitigate errors at distinct steps in translation can evoke similar cellular responses.
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Affiliation(s)
- Markus Terrey
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Section of Neurobiology, Division of Biological Sciences, University of California San DiegoLa JollaUnited States
- Graduate School of Biomedical Sciences and Engineering, University of MaineOronoUnited States
| | - Scott I Adamson
- The Jackson Laboratory for Genomic MedicineFarmingtonUnited States
- Department of Genetics and Genome Sciences, Institute for Systems Genomics, UConn HealthFarmingtonUnited States
| | - Jeffrey H Chuang
- The Jackson Laboratory for Genomic MedicineFarmingtonUnited States
- Department of Genetics and Genome Sciences, Institute for Systems Genomics, UConn HealthFarmingtonUnited States
| | - Susan L Ackerman
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Section of Neurobiology, Division of Biological Sciences, University of California San DiegoLa JollaUnited States
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41
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D'Orazio KN, Green R. Ribosome states signal RNA quality control. Mol Cell 2021; 81:1372-1383. [PMID: 33713598 PMCID: PMC8041214 DOI: 10.1016/j.molcel.2021.02.022] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 02/04/2021] [Accepted: 02/17/2021] [Indexed: 12/18/2022]
Abstract
Eukaryotic cells integrate multiple quality control (QC) responses during protein synthesis in the cytoplasm. These QC responses are signaled by slow or stalled elongating ribosomes. Depending on the nature of the delay, the signal may lead to translational repression, messenger RNA decay, ribosome rescue, and/or nascent protein degradation. Here, we discuss how the structure and composition of an elongating ribosome in a troubled state determine the downstream quality control pathway(s) that ensue. We highlight the intersecting pathways involved in RNA decay and the crosstalk that occurs between RNA decay and ribosome rescue.
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Affiliation(s)
- Karole N D'Orazio
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Rachel Green
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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42
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Abe T, Nagai R, Imataka H, Takeuchi-Tomita N. Reconstitution of yeast translation elongation and termination in vitro utilizing CrPV IRES-containing mRNA. J Biochem 2021; 167:441-450. [PMID: 32053165 DOI: 10.1093/jb/mvaa021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 01/24/2020] [Indexed: 11/13/2022] Open
Abstract
We developed an in vitro translation system from yeast, reconstituted with purified translation elongation and termination factors and programmed by CrPV IGR IRES-containing mRNA, which functions in the absence of initiation factors. The system is capable of synthesizing the active reporter protein, nanoLuciferase, with a molecular weight of 19 kDa. The protein synthesis by the system is appropriately regulated by controlling its composition, including translation factors, amino acids and antibiotics. We found that a high eEF1A concentration relative to the ribosome concentration is critically required for efficient IRES-mediated translation initiation, to ensure its dominance over IRES-independent random internal translation initiation.
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Affiliation(s)
- Taisho Abe
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Riku Nagai
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Hiroaki Imataka
- Department of Materials Science and Chemistry, Graduate School of Engineering, University of Hyogo, Himeji 671-2201, Japan
| | - Nono Takeuchi-Tomita
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
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43
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Mesquita TJB, Sandri JP, de Campos Giordano R, Horta ACL, Zangirolami TC. A High-Throughput Approach for Modeling and Simulation of Homofermentative Microorganisms Applied to Ethanol Fermentation by S. cerevisiae. Ind Biotechnol (New Rochelle N Y) 2021. [DOI: 10.1089/ind.2020.0034] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Affiliation(s)
| | - Juliana Passamani Sandri
- Graduate Program of Chemical Engineering, Federal University of São Carlos, São Carlos, SP, Brazil
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44
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Kratzat H, Mackens-Kiani T, Ameismeier M, Potocnjak M, Cheng J, Dacheux E, Namane A, Berninghausen O, Herzog F, Fromont-Racine M, Becker T, Beckmann R. A structural inventory of native ribosomal ABCE1-43S pre-initiation complexes. EMBO J 2020; 40:e105179. [PMID: 33289941 PMCID: PMC7780240 DOI: 10.15252/embj.2020105179] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 09/21/2020] [Accepted: 09/29/2020] [Indexed: 11/24/2022] Open
Abstract
In eukaryotic translation, termination and ribosome recycling phases are linked to subsequent initiation of a new round of translation by persistence of several factors at ribosomal sub‐complexes. These comprise/include the large eIF3 complex, eIF3j (Hcr1 in yeast) and the ATP‐binding cassette protein ABCE1 (Rli1 in yeast). The ATPase is mainly active as a recycling factor, but it can remain bound to the dissociated 40S subunit until formation of the next 43S pre‐initiation complexes. However, its functional role and native architectural context remains largely enigmatic. Here, we present an architectural inventory of native yeast and human ABCE1‐containing pre‐initiation complexes by cryo‐EM. We found that ABCE1 was mostly associated with early 43S, but also with later 48S phases of initiation. It adopted a novel hybrid conformation of its nucleotide‐binding domains, while interacting with the N‐terminus of eIF3j. Further, eIF3j occupied the mRNA entry channel via its ultimate C‐terminus providing a structural explanation for its antagonistic role with respect to mRNA binding. Overall, the native human samples provide a near‐complete molecular picture of the architecture and sophisticated interaction network of the 43S‐bound eIF3 complex and the eIF2 ternary complex containing the initiator tRNA.
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Affiliation(s)
- Hanna Kratzat
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | - Timur Mackens-Kiani
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | - Michael Ameismeier
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | - Mia Potocnjak
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | - Jingdong Cheng
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | - Estelle Dacheux
- Génétique des Interactions Macromoléculaires, UMR3525 CNRS, Institut Pasteur, Paris, France
| | - Abdelkader Namane
- Génétique des Interactions Macromoléculaires, UMR3525 CNRS, Institut Pasteur, Paris, France
| | - Otto Berninghausen
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | - Franz Herzog
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | | | - Thomas Becker
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
| | - Roland Beckmann
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Munich, Germany
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45
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Terrey M, Adamson SI, Gibson AL, Deng T, Ishimura R, Chuang JH, Ackerman SL. GTPBP1 resolves paused ribosomes to maintain neuronal homeostasis. eLife 2020; 9:e62731. [PMID: 33186095 PMCID: PMC7665888 DOI: 10.7554/elife.62731] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 10/26/2020] [Indexed: 12/14/2022] Open
Abstract
Ribosome-associated quality control pathways respond to defects in translational elongation to recycle arrested ribosomes and degrade aberrant polypeptides and mRNAs. Loss of a tRNA gene leads to ribosomal pausing that is resolved by the translational GTPase GTPBP2, and in its absence causes neuron death. Here, we show that loss of the homologous protein GTPBP1 during tRNA deficiency in the mouse brain also leads to codon-specific ribosome pausing and neurodegeneration, suggesting that these non-redundant GTPases function in the same pathway to mitigate ribosome pausing. As observed in Gtpbp2-/- mice (Ishimura et al., 2016), GCN2-mediated activation of the integrated stress response (ISR) was apparent in the Gtpbp1-/- brain. We observed decreased mTORC1 signaling which increased neuronal death, whereas ISR activation was neuroprotective. Our data demonstrate that GTPBP1 functions as an important quality control mechanism during translation elongation and suggest that translational signaling pathways intricately interact to regulate neuronal homeostasis during defective elongation.
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Affiliation(s)
- Markus Terrey
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Section of Neurobiology, Division of Biological Sciences, University of California, San DiegoSan DiegoUnited States
- Graduate School of Biomedical Sciences and Engineering, University of MaineOronoUnited States
| | - Scott I Adamson
- The Jackson Laboratory for Genomic MedicineFarmingtonUnited States
- Department of Genetics and Genome Sciences, Institute for Systems Genomics, UConn HealthFarmingtonUnited States
| | - Alana L Gibson
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Section of Neurobiology, Division of Biological Sciences, University of California, San DiegoSan DiegoUnited States
| | - Tianda Deng
- Division of Biological Sciences, Section of Molecular Biology, University of California, San DiegoSan DiegoUnited States
| | - Ryuta Ishimura
- The Jackson Laboratory for Mammalian GeneticsBar HarborUnited States
| | - Jeffrey H Chuang
- The Jackson Laboratory for Genomic MedicineFarmingtonUnited States
| | - Susan L Ackerman
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Section of Neurobiology, Division of Biological Sciences, University of California, San DiegoSan DiegoUnited States
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46
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Annibaldis G, Domanski M, Dreos R, Contu L, Carl S, Kläy N, Mühlemann O. Readthrough of stop codons under limiting ABCE1 concentration involves frameshifting and inhibits nonsense-mediated mRNA decay. Nucleic Acids Res 2020; 48:10259-10279. [PMID: 32941650 PMCID: PMC7544199 DOI: 10.1093/nar/gkaa758] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 08/28/2020] [Accepted: 09/09/2020] [Indexed: 12/11/2022] Open
Abstract
To gain insight into the mechanistic link between translation termination and nonsense-mediated mRNA decay (NMD), we depleted the ribosome recycling factor ABCE1 in human cells, resulting in an upregulation of NMD-sensitive mRNAs. Suppression of NMD on these mRNAs occurs prior to their SMG6-mediated endonucleolytic cleavage. ABCE1 depletion caused ribosome stalling at termination codons (TCs) and increased ribosome occupancy in 3′ UTRs, implying enhanced TC readthrough. ABCE1 knockdown indeed increased the rate of readthrough and continuation of translation in different reading frames, providing a possible explanation for the observed NMD inhibition, since enhanced readthrough displaces NMD activating proteins from the 3′ UTR. Our results indicate that stalling at TCs triggers ribosome collisions and activates ribosome quality control. Collectively, we show that improper translation termination can lead to readthrough of the TC, presumably due to ribosome collisions pushing the stalled ribosomes into the 3′ UTR, where it can resume translation in-frame as well as out-of-frame.
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Affiliation(s)
- Giuditta Annibaldis
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Mittelstrasse 43, CH-3012 Bern, Switzerland
| | - Michal Domanski
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - René Dreos
- Center for Integrative Genomics, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Lara Contu
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Mittelstrasse 43, CH-3012 Bern, Switzerland
| | - Sarah Carl
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland
| | - Nina Kläy
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Oliver Mühlemann
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
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47
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Saito K, Green R, Buskirk AR. Ribosome recycling is not critical for translational coupling in Escherichia coli. eLife 2020; 9:59974. [PMID: 32965213 PMCID: PMC7538156 DOI: 10.7554/elife.59974] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 09/22/2020] [Indexed: 12/23/2022] Open
Abstract
We used ribosome profiling to characterize the biological role of ribosome recycling factor (RRF) in Escherichia coli. As expected, RRF depletion leads to enrichment of post-termination 70S complexes in 3′-UTRs. We also observe that elongating ribosomes are unable to complete translation because they are blocked by non-recycled ribosomes at stop codons. Previous studies have suggested a role for recycling in translational coupling within operons; if a ribosome remains bound to an mRNA after termination, it may re-initiate downstream. We found, however, that RRF depletion did not significantly affect coupling efficiency in reporter assays or in ribosome density genome-wide. These findings argue that re-initiation is not a major mechanism of translational coupling in E. coli. Finally, RRF depletion has dramatic effects on the activity of ribosome rescue factors tmRNA and ArfA. Our results provide a global view of the effects of the loss of ribosome recycling on protein synthesis in E. coli.
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Affiliation(s)
- Kazuki Saito
- Department of Molecular Biology and Genetics, Baltimore, United States
| | - Rachel Green
- Department of Molecular Biology and Genetics, Baltimore, United States.,Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Allen R Buskirk
- Department of Molecular Biology and Genetics, Baltimore, United States
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48
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Gouridis G, Hetzert B, Kiosze-Becker K, de Boer M, Heinemann H, Nürenberg-Goloub E, Cordes T, Tampé R. ABCE1 Controls Ribosome Recycling by an Asymmetric Dynamic Conformational Equilibrium. Cell Rep 2020; 28:723-734.e6. [PMID: 31315050 PMCID: PMC6656783 DOI: 10.1016/j.celrep.2019.06.052] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 02/04/2019] [Accepted: 06/14/2019] [Indexed: 11/04/2022] Open
Abstract
The twin-ATPase ABCE1 has a vital function in mRNA translation by recycling terminated or stalled ribosomes. As for other functionally distinct ATP-binding cassette (ABC) proteins, the mechanochemical coupling of ATP hydrolysis to conformational changes remains elusive. Here, we use an integrated biophysical approach allowing direct observation of conformational dynamics and ribosome association of ABCE1 at the single-molecule level. Our results from FRET experiments show that the current static two-state model of ABC proteins has to be expanded because the two ATP sites of ABCE1 are in dynamic equilibrium across three distinct conformational states: open, intermediate, and closed. The interaction of ABCE1 with ribosomes influences the conformational dynamics of both ATP sites asymmetrically and creates a complex network of conformational states. Our findings suggest a paradigm shift to redefine the understanding of the mechanochemical coupling in ABC proteins: from structure-based deterministic models to dynamic-based systems. Both ATP sites of ABCE1 are in an asymmetric conformational equilibrium Each ATP site can adopt three functionally distinct conformational states These equilibria shift during ribosome recycling depending on interaction partners ATP binding, but not hydrolysis, is required for ribosome splitting
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Affiliation(s)
- Giorgos Gouridis
- Molecular Microscopy Research Group, Zernike Institute for Advanced Material, University of Groningen, 9747 AG Groningen, the Netherlands; Physical and Synthetic Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany; Department of Microbiology and Immunology, Rega Institute for Medical Research, Laboratory of Molecular Bacteriology, KU Leuven, 3000 Leuven, Belgium
| | - Bianca Hetzert
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, 60438 Frankfurt a.M., Germany
| | - Kristin Kiosze-Becker
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, 60438 Frankfurt a.M., Germany
| | - Marijn de Boer
- Molecular Microscopy Research Group, Zernike Institute for Advanced Material, University of Groningen, 9747 AG Groningen, the Netherlands
| | - Holger Heinemann
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, 60438 Frankfurt a.M., Germany
| | - Elina Nürenberg-Goloub
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, 60438 Frankfurt a.M., Germany
| | - Thorben Cordes
- Molecular Microscopy Research Group, Zernike Institute for Advanced Material, University of Groningen, 9747 AG Groningen, the Netherlands; Physical and Synthetic Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany.
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, 60438 Frankfurt a.M., Germany.
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49
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Young DJ, Guydosh NR. Hcr1/eIF3j Is a 60S Ribosomal Subunit Recycling Accessory Factor In Vivo. Cell Rep 2020; 28:39-50.e4. [PMID: 31269449 DOI: 10.1016/j.celrep.2019.05.111] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 04/26/2019] [Accepted: 05/30/2019] [Indexed: 02/07/2023] Open
Abstract
Hcr1/eIF3j is a sub-stoichiometric subunit of eukaryotic initiation factor 3 (eIF3) that can dissociate the post-termination 40S ribosomal subunit from mRNA in vitro. We examine this ribosome recycling role in vivo by ribosome profiling and reporter assays and find that loss of Hcr1 leads to reinitiation of translation in 3' UTRs, consistent with a defect in recycling. However, the defect appears to be in the recycling of the 60S subunit, rather than the 40S subunit, because reinitiation does not require an AUG codon and is suppressed by overexpression of the 60S dissociation factor Rli1/ABCE1. Consistent with a 60S recycling role, overexpression of Hcr1 cannot compensate for loss of 40S recycling factors Tma64/eIF2D and Tma20/MCT-1. Intriguingly, loss of Hcr1 triggers greater expression of RLI1 via an apparent feedback loop. These findings suggest Hcr1/eIF3j is recruited to ribosomes at stop codons and may coordinate the transition to a new round of translation.
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Affiliation(s)
- David J Young
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD 20892, USA
| | - Nicholas R Guydosh
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD 20892, USA.
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50
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Juszkiewicz S, Speldewinde SH, Wan L, Svejstrup JQ, Hegde RS. The ASC-1 Complex Disassembles Collided Ribosomes. Mol Cell 2020; 79:603-614.e8. [PMID: 32579943 PMCID: PMC7447978 DOI: 10.1016/j.molcel.2020.06.006] [Citation(s) in RCA: 100] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 06/01/2020] [Accepted: 06/01/2020] [Indexed: 02/03/2023]
Abstract
Translating ribosomes that slow excessively incur collisions with trailing ribosomes. Persistent collisions are detected by ZNF598, a ubiquitin ligase that ubiquitinates sites on the ribosomal 40S subunit to initiate pathways of mRNA and protein quality control. The collided ribosome complex must be disassembled to initiate downstream quality control, but the mechanistic basis of disassembly is unclear. Here, we reconstitute the disassembly of a collided polysome in a mammalian cell-free system. The widely conserved ASC-1 complex (ASCC) containing the ASCC3 helicase disassembles the leading ribosome in an ATP-dependent reaction. Disassembly, but not ribosome association, requires 40S ubiquitination by ZNF598, but not GTP-dependent factors, including the Pelo-Hbs1L ribosome rescue complex. Trailing ribosomes can elongate once the roadblock has been removed and only become targets if they subsequently stall and incur collisions. These findings define the specific role of ASCC during ribosome-associated quality control and identify the molecular target of its activity.
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Affiliation(s)
- Szymon Juszkiewicz
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | | | - Li Wan
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | | | - Ramanujan S Hegde
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK.
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