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Horvath A, Janapala Y, Woodward K, Mahmud S, Cleynen A, Gardiner E, Hannan R, Eyras E, Preiss T, Shirokikh N. Comprehensive translational profiling and STE AI uncover rapid control of protein biosynthesis during cell stress. Nucleic Acids Res 2024; 52:7925-7946. [PMID: 38721779 PMCID: PMC11260467 DOI: 10.1093/nar/gkae365] [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: 01/09/2024] [Revised: 03/21/2024] [Accepted: 04/25/2024] [Indexed: 07/23/2024] Open
Abstract
Translational control is important in all life, but it remains a challenge to accurately quantify. When ribosomes translate messenger (m)RNA into proteins, they attach to the mRNA in series, forming poly(ribo)somes, and can co-localize. Here, we computationally model new types of co-localized ribosomal complexes on mRNA and identify them using enhanced translation complex profile sequencing (eTCP-seq) based on rapid in vivo crosslinking. We detect long disome footprints outside regions of non-random elongation stalls and show these are linked to translation initiation and protein biosynthesis rates. We subject footprints of disomes and other translation complexes to artificial intelligence (AI) analysis and construct a new, accurate and self-normalized measure of translation, termed stochastic translation efficiency (STE). We then apply STE to investigate rapid changes to mRNA translation in yeast undergoing glucose depletion. Importantly, we show that, well beyond tagging elongation stalls, footprints of co-localized ribosomes provide rich insight into translational mechanisms, polysome dynamics and topology. STE AI ranks cellular mRNAs by absolute translation rates under given conditions, can assist in identifying its control elements and will facilitate the development of next-generation synthetic biology designs and mRNA-based therapeutics.
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Affiliation(s)
- Attila Horvath
- Division of Genome Sciences and Cancer, The John Curtin School of Medical Research, and The Shine-Dalgarno Centre for RNA Innovation, The Australian National University, Canberra, ACT 2601, Australia
| | - Yoshika Janapala
- Division of Genome Sciences and Cancer, The John Curtin School of Medical Research, and The Shine-Dalgarno Centre for RNA Innovation, The Australian National University, Canberra, ACT 2601, Australia
| | - Katrina Woodward
- Division of Genome Sciences and Cancer, The John Curtin School of Medical Research, and The Shine-Dalgarno Centre for RNA Innovation, The Australian National University, Canberra, ACT 2601, Australia
| | - Shafi Mahmud
- Division of Genome Sciences and Cancer, The John Curtin School of Medical Research, and The Shine-Dalgarno Centre for RNA Innovation, The Australian National University, Canberra, ACT 2601, Australia
| | - Alice Cleynen
- Division of Genome Sciences and Cancer, The John Curtin School of Medical Research, and The Shine-Dalgarno Centre for RNA Innovation, The Australian National University, Canberra, ACT 2601, Australia
- Institut Montpelliérain Alexander Grothendieck, Université de Montpellier, CNRS, Montpellier, France
| | - Elizabeth E Gardiner
- Division of Genome Sciences and Cancer, The John Curtin School of Medical Research, and The National Platelet Research and Referral Centre, The Australian National University, Canberra, ACT 2601, Australia
| | - Ross D Hannan
- Division of Genome Sciences and Cancer, The John Curtin School of Medical Research, and The Shine-Dalgarno Centre for RNA Innovation, The Australian National University, Canberra, ACT 2601, Australia
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville 3010, Australia
- Peter MacCallum Cancer Centre, Melbourne 3000, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Clayton 3800, Australia
- School of Biomedical Sciences, University of Queensland, St Lucia 4067, Australia
| | - Eduardo Eyras
- Division of Genome Sciences and Cancer, The John Curtin School of Medical Research, and The Shine-Dalgarno Centre for RNA Innovation, The Australian National University, Canberra, ACT 2601, Australia
- Division of Genome Sciences and Cancer, The John Curtin School of Medical Research, and The Centre for Computational Biomedical Sciences, The Australian National University, Canberra, ACT 2601, Australia
- EMBL Australia Partner Laboratory Network at the Australian National University, Canberra, ACT 2601, Australia
| | - Thomas Preiss
- Division of Genome Sciences and Cancer, The John Curtin School of Medical Research, and The Shine-Dalgarno Centre for RNA Innovation, The Australian National University, Canberra, ACT 2601, Australia
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
| | - Nikolay E Shirokikh
- Division of Genome Sciences and Cancer, The John Curtin School of Medical Research, and The Shine-Dalgarno Centre for RNA Innovation, The Australian National University, Canberra, ACT 2601, Australia
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2
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Komar AA, Samatova E, Rodnina MV. Translation Rates and Protein Folding. J Mol Biol 2024; 436:168384. [PMID: 38065274 DOI: 10.1016/j.jmb.2023.168384] [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: 10/20/2023] [Revised: 12/01/2023] [Accepted: 12/02/2023] [Indexed: 12/19/2023]
Abstract
The mRNA coding sequence defines not only the amino acid sequence of the protein, but also the speed at which the ribosomes move along the mRNA while making the protein. The non-uniform local kinetics - denoted as translational rhythm - is similar among mRNAs coding for related protein folds. Deviations from this conserved rhythm can result in protein misfolding. In this review we summarize the experimental evidence demonstrating how local translation rates affect cotranslational protein folding, with the focus on the synonymous codons and patches of charged residues in the nascent peptide as best-studied examples. Alterations in nascent protein conformations due to disturbed translational rhythm can persist off the ribosome, as demonstrated by the effects of synonymous codon variants of several disease-related proteins. Charged amino acid patches in nascent chains also modulate translation and cotranslational protein folding, and can abrogate translation when placed at the N-terminus of the nascent peptide. During cotranslational folding, incomplete nascent chains navigate through a unique conformational landscape in which earlier intermediate states become inaccessible as the nascent peptide grows. Precisely tuned local translation rates, as well as interactions with the ribosome, guide the folding pathway towards the native structure, whereas deviations from the natural translation rhythm may favor pathways leading to trapped misfolded states. Deciphering the 'folding code' of the mRNA will contribute to understanding the diseases caused by protein misfolding and to rational protein design.
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Affiliation(s)
- Anton A Komar
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological and Environmental Sciences, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44115, USA; Department of Biochemistry and Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.
| | - Ekaterina Samatova
- Max Planck Department of Physical Biochemistry, Max Planck Institute for Multidisciplinary Sciences, 37077 Goettingen, Germany
| | - Marina V Rodnina
- Max Planck Department of Physical Biochemistry, Max Planck Institute for Multidisciplinary Sciences, 37077 Goettingen, Germany.
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3
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Chen KY, Park H, Subramaniam AR. Massively parallel identification of sequence motifs triggering ribosome-associated mRNA quality control. Nucleic Acids Res 2024; 52:7171-7187. [PMID: 38647082 PMCID: PMC11229359 DOI: 10.1093/nar/gkae285] [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: 09/21/2023] [Revised: 02/28/2024] [Accepted: 04/04/2024] [Indexed: 04/25/2024] Open
Abstract
Decay of mRNAs can be triggered by ribosome slowdown at stretches of rare codons or positively charged amino acids. However, the full diversity of sequences that trigger co-translational mRNA decay is poorly understood. To comprehensively identify sequence motifs that trigger mRNA decay, we use a massively parallel reporter assay to measure the effect of all possible combinations of codon pairs on mRNA levels in S. cerevisiae. In addition to known mRNA-destabilizing sequences, we identify several dipeptide repeats whose translation reduces mRNA levels. These include combinations of positively charged and bulky residues, as well as proline-glycine and proline-aspartate dipeptide repeats. Genetic deletion of the ribosome collision sensor Hel2 rescues the mRNA effects of these motifs, suggesting that they trigger ribosome slowdown and activate the ribosome-associated quality control (RQC) pathway. Deep mutational scanning of an mRNA-destabilizing dipeptide repeat reveals a complex interplay between the charge, bulkiness, and location of amino acid residues in conferring mRNA instability. Finally, we show that the mRNA effects of codon pairs are predictive of the effects of endogenous sequences. Our work highlights the complexity of sequence motifs driving co-translational mRNA decay in eukaryotes, and presents a high throughput approach to dissect their requirements at the codon level.
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Affiliation(s)
- Katharine Y Chen
- Basic Sciences Division and Computational Biology Section of the Public Health Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
- Molecular and Cellular Biology Program, University of Washington, Seattle, WA 98195, USA
| | - Heungwon Park
- Basic Sciences Division and Computational Biology Section of the Public Health Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Arvind Rasi Subramaniam
- Basic Sciences Division and Computational Biology Section of the Public Health Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, 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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Takada H, Fujiwara K, Atkinson GC, Chiba S, Hauryliuk V. Resolution of ribosomal stalling by EF-P and ABCF ATPases YfmR and YkpA/YbiT. Nucleic Acids Res 2024:gkae556. [PMID: 38943426 DOI: 10.1093/nar/gkae556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 06/11/2024] [Accepted: 06/25/2024] [Indexed: 07/01/2024] Open
Abstract
Efficiency of protein synthesis on the ribosome is strongly affected by the amino acid composition of the assembled amino acid chain. Challenging sequences include proline-rich motifs as well as highly positively and negatively charged amino acid stretches. Members of the F subfamily of ABC ATPases (ABCFs) have been long hypothesised to promote translation of such problematic motifs. In this study we have applied genetics and reporter-based assays to characterise the four housekeeping ABCF ATPases of Bacillus subtilis: YdiF, YfmM, YfmR/Uup and YkpA/YbiT. We show that YfmR cooperates with the translation factor EF-P that promotes translation of Pro-rich motifs. Simultaneous loss of both YfmR and EF-P results in a dramatic growth defect. Surprisingly, this growth defect can be largely suppressed though overexpression of an EF-P variant lacking the otherwise crucial 5-amino-pentanolylated residue K32. Using in vivo reporter assays, we show that overexpression of YfmR can alleviate ribosomal stalling on Asp-Pro motifs. Finally, we demonstrate that YkpA/YbiT promotes translation of positively and negatively charged motifs but is inactive in resolving ribosomal stalls on proline-rich stretches. Collectively, our results provide insights into the function of ABCF translation factors in modulating protein synthesis in B. subtilis.
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Affiliation(s)
- Hiraku Takada
- Faculty of Life Sciences and Institute for Protein Dynamics, Kyoto Sangyo University, Kamigamo, Motoyama, Kita-ku, Kyoto 603-8555, Japan
- Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | - Keigo Fujiwara
- Faculty of Life Sciences and Institute for Protein Dynamics, Kyoto Sangyo University, Kamigamo, Motoyama, Kita-ku, Kyoto 603-8555, Japan
| | - Gemma C Atkinson
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
- Virus Centre, Lund University, Lund, Sweden
| | - Shinobu Chiba
- Faculty of Life Sciences and Institute for Protein Dynamics, Kyoto Sangyo University, Kamigamo, Motoyama, Kita-ku, Kyoto 603-8555, Japan
| | - Vasili Hauryliuk
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
- Virus Centre, Lund University, Lund, Sweden
- University of Tartu, Institute of Technology, 50411 Tartu, Estonia
- Science for Life Laboratory, Lund, Sweden
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6
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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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7
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Miścicka A, Bulakhov AG, Kuroha K, Zinoviev A, Hellen CT, Pestova T. Ribosomal collision is not a prerequisite for ZNF598-mediated ribosome ubiquitination and disassembly of ribosomal complexes by ASCC. Nucleic Acids Res 2024; 52:4627-4643. [PMID: 38366554 PMCID: PMC11077048 DOI: 10.1093/nar/gkae087] [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: 12/01/2023] [Revised: 01/12/2024] [Accepted: 01/29/2024] [Indexed: 02/18/2024] Open
Abstract
Ribosomal stalling induces the ribosome-associated quality control (RQC) pathway targeting aberrant polypeptides. RQC is initiated by K63-polyubiquitination of ribosomal protein uS10 located at the mRNA entrance of stalled ribosomes by the E3 ubiquitin ligase ZNF598 (Hel2 in yeast). Ubiquitinated ribosomes are dissociated by the ASC-1 complex (ASCC) (RQC-Trigger (RQT) complex in yeast). A cryo-EM structure of the ribosome-bound RQT complex suggested the dissociation mechanism, in which the RNA helicase Slh1 subunit of RQT (ASCC3 in mammals) applies a pulling force on the mRNA, inducing destabilizing conformational changes in the 40S subunit, whereas the collided ribosome acts as a wedge, promoting subunit dissociation. Here, using an in vitro reconstitution approach, we found that ribosomal collision is not a strict prerequisite for ribosomal ubiquitination by ZNF598 or for ASCC-mediated ribosome release. Following ubiquitination by ZNF598, ASCC efficiently dissociated all polysomal ribosomes in a stalled queue, monosomes assembled in RRL, in vitro reconstituted 80S elongation complexes in pre- and post-translocated states, and 48S initiation complexes, as long as such complexes contained ≥ 30-35 3'-terminal mRNA nt. downstream from the P site and sufficiently long ubiquitin chains. Dissociation of polysomes and monosomes both involved ribosomal splitting, enabling Listerin-mediated ubiquitination of 60S-associated nascent chains.
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Affiliation(s)
- Anna Miścicka
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
| | - Alexander G Bulakhov
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
| | - Kazushige Kuroha
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
| | - Alexandra Zinoviev
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
| | - Christopher U T Hellen
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
| | - Tatyana V Pestova
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
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8
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Inada T, Beckmann R. Mechanisms of Translation-coupled Quality Control. J Mol Biol 2024; 436:168496. [PMID: 38365086 DOI: 10.1016/j.jmb.2024.168496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 02/05/2024] [Accepted: 02/12/2024] [Indexed: 02/18/2024]
Abstract
Stalling of ribosomes engaged in protein synthesis can lead to significant defects in the function of newly synthesized proteins and thereby impair protein homeostasis. Consequently, partially synthesized polypeptides resulting from translation stalling are recognized and eliminated by several quality control mechanisms. First, if translation elongation reactions are halted prematurely, a quality control mechanism called ribosome-associated quality control (RQC) initiates the ubiquitination of the nascent polypeptide chain and subsequent proteasomal degradation. Additionally, when ribosomes with defective codon recognition or peptide-bond formation stall during translation, a quality control mechanism known as non-functional ribosomal RNA decay (NRD) leads to the degradation of malfunctioning ribosomes. In both of these quality control mechanisms, E3 ubiquitin ligases selectively recognize ribosomes in distinct translation-stalling states and ubiquitinate specific ribosomal proteins. Significant efforts have been devoted to characterize E3 ubiquitin ligase sensing of ribosome 'collision' or 'stalling' and subsequent ribosome is rescued. This article provides an overview of our current understanding of the molecular mechanisms and physiological functions of ribosome dynamics control and quality control of abnormal translation.
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Affiliation(s)
- Toshifumi Inada
- Division of RNA and Gene Regulation, Institute of Medical Science, The University of Tokyo, Minato-Ku, Tokyo 108-8639, Japan.
| | - Roland Beckmann
- Gene Center and Department of Biochemistry, Feodor-Lynen-Str. 25, University of Munich, 81377 Munich, Germany.
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9
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Sng CCT, Kallor AA, Simpson BS, Bedran G, Alfaro J, Litchfield K. Untranslated regions (UTRs) are a potential novel source of neoantigens for personalised immunotherapy. Front Immunol 2024; 15:1347542. [PMID: 38558815 PMCID: PMC10978585 DOI: 10.3389/fimmu.2024.1347542] [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] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 02/19/2024] [Indexed: 04/04/2024] Open
Abstract
Background Neoantigens, mutated tumour-specific antigens, are key targets of anti-tumour immunity during checkpoint inhibitor (CPI) treatment. Their identification is fundamental to designing neoantigen-directed therapy. Non-canonical neoantigens arising from the untranslated regions (UTR) of the genome are an overlooked source of immunogenic neoantigens. Here, we describe the landscape of UTR-derived neoantigens and release a computational tool, PrimeCUTR, to predict UTR neoantigens generated by start-gain and stop-loss mutations. Methods We applied PrimeCUTR to a whole genome sequencing dataset of pre-treatment tumour samples from CPI-treated patients (n = 341). Cancer immunopeptidomic datasets were interrogated to identify MHC class I presentation of UTR neoantigens. Results Start-gain neoantigens were predicted in 72.7% of patients, while stop-loss mutations were found in 19.3% of patients. While UTR neoantigens only accounted 2.6% of total predicted neoantigen burden, they contributed 12.4% of neoantigens with high dissimilarity to self-proteome. More start-gain neoantigens were found in CPI responders, but this relationship was not significant when correcting for tumour mutational burden. While most UTR neoantigens are private, we identified two recurrent start-gain mutations in melanoma. Using immunopeptidomic datasets, we identify two distinct MHC class I-presented UTR neoantigens: one from a recurrent start-gain mutation in melanoma, and one private to Jurkat cells. Conclusion PrimeCUTR is a novel tool which complements existing neoantigen discovery approaches and has potential to increase the detection yield of neoantigens in personalised therapeutics, particularly for neoantigens with high dissimilarity to self. Further studies are warranted to confirm the expression and immunogenicity of UTR neoantigens.
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Affiliation(s)
- Christopher C. T. Sng
- Cancer Research UK Lung Cancer Centre of Excellence, University College London (UCL) Cancer Institute, London, United Kingdom
| | - Ashwin Adrian Kallor
- International Center for Cancer Vaccine Science, University of Gdansk, Gdansk, Poland
| | - Benjamin S. Simpson
- Cancer Research UK Lung Cancer Centre of Excellence, University College London (UCL) Cancer Institute, London, United Kingdom
| | - Georges Bedran
- International Center for Cancer Vaccine Science, University of Gdansk, Gdansk, Poland
| | - Javier Alfaro
- International Center for Cancer Vaccine Science, University of Gdansk, Gdansk, Poland
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
- Institute for Adaptive and Neural Computation, School of Informatics, University of Edinburgh, Edinburgh, United Kingdom
| | - Kevin Litchfield
- Cancer Research UK Lung Cancer Centre of Excellence, University College London (UCL) Cancer Institute, London, United Kingdom
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10
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Geng J, Li S, Li Y, Wu Z, Bhurtel S, Rimal S, Khan D, Ohja R, Brandman O, Lu B. Stalled translation by mitochondrial stress upregulates a CNOT4-ZNF598 ribosomal quality control pathway important for tissue homeostasis. Nat Commun 2024; 15:1637. [PMID: 38388640 PMCID: PMC10883933 DOI: 10.1038/s41467-024-45525-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 01/26/2024] [Indexed: 02/24/2024] Open
Abstract
Translational control exerts immediate effect on the composition, abundance, and integrity of the proteome. Ribosome-associated quality control (RQC) handles ribosomes stalled at the elongation and termination steps of translation, with ZNF598 in mammals and Hel2 in yeast serving as key sensors of translation stalling and coordinators of downstream resolution of collided ribosomes, termination of stalled translation, and removal of faulty translation products. The physiological regulation of RQC in general and ZNF598 in particular in multicellular settings is underexplored. Here we show that ZNF598 undergoes regulatory K63-linked ubiquitination in a CNOT4-dependent manner and is upregulated upon mitochondrial stresses in mammalian cells and Drosophila. ZNF598 promotes resolution of stalled ribosomes and protects against mitochondrial stress in a ubiquitination-dependent fashion. In Drosophila models of neurodegenerative diseases and patient cells, ZNF598 overexpression aborts stalled translation of mitochondrial outer membrane-associated mRNAs, removes faulty translation products causal of disease, and improves mitochondrial and tissue health. These results shed lights on the regulation of ZNF598 and its functional role in mitochondrial and tissue homeostasis.
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Affiliation(s)
- Ji Geng
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
| | - Shuangxi Li
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, 94305, USA
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, 266237, China
| | - Yu Li
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, 94305, USA
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, 266237, China
| | - Zhihao Wu
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Sunil Bhurtel
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Suman Rimal
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Danish Khan
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Rani Ohja
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Onn Brandman
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Bingwei Lu
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
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11
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Acosta-Reyes FJ, Bhattacharjee S, Gottesman M, Frank J. How Dedicated Ribosomes Translate a Leaderless mRNA. J Mol Biol 2024; 436:168423. [PMID: 38185325 PMCID: PMC11003707 DOI: 10.1016/j.jmb.2023.168423] [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: 10/13/2023] [Revised: 12/15/2023] [Accepted: 12/26/2023] [Indexed: 01/09/2024]
Abstract
In bacteriophage λ lysogens, the λcI repressor is encoded by the leaderless transcript (lmRNA) initiated at the λpRM promoter. Translation is enhanced in rpsB mutants deficient in ribosomal protein uS2. Although translation initiation of lmRNA is conserved in bacteria, archaea, and eukaryotes, structural insight of a lmRNA translation initiation complex is missing. Here, we use cryo-EM to solve the structures of the uS2-deficient 70S ribosome of host E. coli mutant rpsB11 and the wild-type 70S complex with λcI lmRNA and fMet-tRNAfMet. Importantly, the uS2-deficient 70S ribosome also lacks protein bS21. The anti-Shine-Dalgarno (aSD) region is structurally supported by bS21, so that the absence of the latter causes the aSD to divert from the normal mRNA exit pathway, easing the exit of lmRNA. A π-stacking interaction between the monitor base A1493 and A(+4) of lmRNA potentially acts as a recognition signal. Coulomb charge flow, along with peristalsis-like dynamics within the mRNA entrance channel due to the increased 30S head rotation caused by the absence of uS2, are likely to facilitate the propagation of lmRNA through the ribosome. These findings lay the groundwork for future research on the mechanism of translation and the co-evolution of lmRNA and mRNA that includes the emergence of a defined ribosome-binding site of the transcript.
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Affiliation(s)
- Francisco J Acosta-Reyes
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Sayan Bhattacharjee
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Max Gottesman
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA; Department of Microbiology & Immunology, Columbia University, New York, NY 10032, USA
| | - Joachim Frank
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA; Department of Biological Sciences, Columbia University, New York, NY 10027, USA
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12
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Svetlov MS, Dunand CF, Nakamoto JA, Atkinson GC, Safdari HA, Wilson DN, Vázquez-Laslop N, Mankin AS. Peptidyl-tRNA hydrolase is the nascent chain release factor in bacterial ribosome-associated quality control. Mol Cell 2024; 84:715-726.e5. [PMID: 38183984 DOI: 10.1016/j.molcel.2023.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 11/08/2023] [Accepted: 12/01/2023] [Indexed: 01/08/2024]
Abstract
Rescuing stalled ribosomes often involves their splitting into subunits. In many bacteria, the resultant large subunits bearing peptidyl-tRNAs are processed by the ribosome-associated quality control (RQC) apparatus that extends the C termini of the incomplete nascent polypeptides with polyalanine tails to facilitate their degradation. Although the tailing mechanism is well established, it is unclear how the nascent polypeptides are cleaved off the tRNAs. We show that peptidyl-tRNA hydrolase (Pth), the known role of which has been to hydrolyze ribosome-free peptidyl-tRNA, acts in concert with RQC factors to release nascent polypeptides from large ribosomal subunits. Dislodging from the ribosomal catalytic center is required for peptidyl-tRNA hydrolysis by Pth. Nascent protein folding may prevent peptidyl-tRNA retraction and interfere with the peptide release. However, oligoalanine tailing makes the peptidyl-tRNA ester bond accessible for Pth-catalyzed hydrolysis. Therefore, the oligoalanine tail serves not only as a degron but also as a facilitator of Pth-catalyzed peptidyl-tRNA hydrolysis.
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Affiliation(s)
- Maxim S Svetlov
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA; Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA.
| | - Clémence F Dunand
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA; Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Jose A Nakamoto
- Department of Experimental Medicine, University of Lund, 221 00 Lund, Sweden
| | - Gemma C Atkinson
- Department of Experimental Medicine, University of Lund, 221 00 Lund, Sweden
| | - Haaris A Safdari
- 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
| | - Nora Vázquez-Laslop
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA; Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Alexander S Mankin
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA; Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA.
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13
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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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14
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Krempl C, Lazzaretti D, Sprangers R. A structural biology view on the enzymes involved in eukaryotic mRNA turnover. Biol Chem 2023; 404:1101-1121. [PMID: 37709756 DOI: 10.1515/hsz-2023-0182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 08/24/2023] [Indexed: 09/16/2023]
Abstract
The cellular environment contains numerous ribonucleases that are dedicated to process mRNA transcripts that have been targeted for degradation. Here, we review the three dimensional structures of the ribonuclease complexes (Pan2-Pan3, Ccr4-Not, Xrn1, exosome) and the mRNA decapping enzymes (Dcp2, DcpS) that are involved in mRNA turnover. Structures of major parts of these proteins have been experimentally determined. These enzymes and factors do not act in isolation, but are embedded in interaction networks which regulate enzyme activity and ensure that the appropriate substrates are recruited. The structural details of the higher order complexes that form can, in part, be accurately deduced from known structural data of sub-complexes. Interestingly, many of the ribonuclease and decapping enzymes have been observed in structurally different conformations. Together with experimental data, this highlights that structural changes are often important for enzyme function. We conclude that the known structural data of mRNA decay factors provide important functional insights, but that static structural data needs to be complemented with information regarding protein motions to complete the picture of how transcripts are turned over. In addition, we highlight multiple aspects that influence mRNA turnover rates, but that have not been structurally characterized so far.
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Affiliation(s)
- Christina Krempl
- Institute of Biophysics and Physical Biochemistry, Regensburg Center for Biochemistry, University of Regensburg, D-93053 Regensburg, Germany
| | - Daniela Lazzaretti
- Institute of Biophysics and Physical Biochemistry, Regensburg Center for Biochemistry, University of Regensburg, D-93053 Regensburg, Germany
| | - Remco Sprangers
- Institute of Biophysics and Physical Biochemistry, Regensburg Center for Biochemistry, University of Regensburg, D-93053 Regensburg, Germany
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15
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Acosta-Reyes FJ, Bhattacharjee S, Gottesman M, Frank J. Structural insight into translation initiation of the λcl leaderless mRNA. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.02.556006. [PMID: 37693525 PMCID: PMC10491246 DOI: 10.1101/2023.09.02.556006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
In bacteriophage λ lysogens, the λcI repressor is encoded by the leaderless transcript (lmRNA) initiated at the λpRM promoter. Translation is enhanced in rpsB mutants deficient in ribosomal protein uS2. Although translation initiation of lmRNA is conserved in bacteria, archaea, and eukaryotes, structural insight of a lmRNA translation initiation complex is missing. Here, we use cryo-EM to solve the structures of the uS2-deficient 70S ribosome of host E. coli mutant rpsB11 and the wild-type 70S complex with λcI lmRNA and fmet-tRNAfMet. Importantly, the uS2-deficient 70S ribosome also lacks protein bS21. The anti-Shine-Dalgarno (aSD) region is structurally supported by bS21, so that the absence of the latter causes the aSD to divert from the normal mRNA exit pathway, easing the exit of lmRNA. A π-stacking interaction between the monitor base A1493 and A(+4) of lmRNA potentially acts as a recognition signal. Coulomb charge flow, along with peristalsis-like dynamics within the mRNA entry channel due to the increased 30S head rotation caused by the absence of uS2, are likely to facilitate the propagation of lmRNA through the ribosome. These findings lay the groundwork for future research on the mechanism of translation and the co-evolution of lmRNA and mRNA that includes the emergence of a defined ribosome-binding site of the transcript.
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Affiliation(s)
- Francisco J Acosta-Reyes
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, 10032, USA
| | - Sayan Bhattacharjee
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, 10032, USA
| | - Max Gottesman
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, 10032, USA
- Department of Microbiology & Immunology, Columbia University, New York, NY, 10032, USA
| | - Joachim Frank
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, 10032, USA
- Department of Biological Sciences, Columbia University, New York, NY, 10027, USA
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16
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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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17
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Monaghan L, Longman D, Cáceres JF. Translation-coupled mRNA quality control mechanisms. EMBO J 2023; 42:e114378. [PMID: 37605642 PMCID: PMC10548175 DOI: 10.15252/embj.2023114378] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 07/24/2023] [Accepted: 08/01/2023] [Indexed: 08/23/2023] Open
Abstract
mRNA surveillance pathways are essential for accurate gene expression and to maintain translation homeostasis, ensuring the production of fully functional proteins. Future insights into mRNA quality control pathways will enable us to understand how cellular mRNA levels are controlled, how defective or unwanted mRNAs can be eliminated, and how dysregulation of these can contribute to human disease. Here we review translation-coupled mRNA quality control mechanisms, including the non-stop and no-go mRNA decay pathways, describing their mechanisms, shared trans-acting factors, and differences. We also describe advances in our understanding of the nonsense-mediated mRNA decay (NMD) pathway, highlighting recent mechanistic findings, the discovery of novel factors, as well as the role of NMD in cellular physiology and its impact on human disease.
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Affiliation(s)
- Laura Monaghan
- MRC Human Genetics Unit, Institute of Genetics and CancerUniversity of EdinburghEdinburghUK
| | - Dasa Longman
- MRC Human Genetics Unit, Institute of Genetics and CancerUniversity of EdinburghEdinburghUK
| | - Javier F Cáceres
- MRC Human Genetics Unit, Institute of Genetics and CancerUniversity of EdinburghEdinburghUK
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18
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Chen KY, Park H, Subramaniam AR. Massively parallel identification of sequence motifs triggering ribosome-associated mRNA quality control. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.27.559793. [PMID: 37808677 PMCID: PMC10557687 DOI: 10.1101/2023.09.27.559793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Decay of mRNAs can be triggered by ribosome slowdown at stretches of rare codons or positively charged amino acids. However, the full diversity of sequences that trigger co-translational mRNA decay is poorly understood. To comprehensively identify sequence motifs that trigger mRNA decay, we use a massively parallel reporter assay to measure the effect of all possible combinations of codon pairs on mRNA levels in S. cerevisiae. In addition to known mRNA-destabilizing sequences, we identify several dipeptide repeats whose translation reduces mRNA levels. These include combinations of positively charged and bulky residues, as well as proline-glycine and proline-aspartate dipeptide repeats. Genetic deletion of the ribosome collision sensor Hel2 rescues the mRNA effects of these motifs, suggesting that they trigger ribosome slowdown and activate the ribosome-associated quality control (RQC) pathway. Deep mutational scanning of an mRNA-destabilizing dipeptide repeat reveals a complex interplay between the charge, bulkiness, and location of amino acid residues in conferring mRNA instability. Finally, we show that the mRNA effects of codon pairs are predictive of the effects of endogenous sequences. Our work highlights the complexity of sequence motifs driving co-translational mRNA decay in eukaryotes, and presents a high throughput approach to dissect their requirements at the codon level.
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Affiliation(s)
- Katharine Y. Chen
- Basic Sciences Division and Computational Biology Section of the Public Health Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
- Molecular and Cellular Biology Program, University of Washington, Seattle, WA 98195, USA
| | - Heungwon Park
- Basic Sciences Division and Computational Biology Section of the Public Health Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Arvind Rasi Subramaniam
- Basic Sciences Division and Computational Biology Section of the Public Health Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
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19
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Absmeier E, Chandrasekaran V, O'Reilly FJ, Stowell JAW, Rappsilber J, Passmore LA. Specific recognition and ubiquitination of translating ribosomes by mammalian CCR4-NOT. Nat Struct Mol Biol 2023; 30:1314-1322. [PMID: 37653243 PMCID: PMC7615087 DOI: 10.1038/s41594-023-01075-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 07/24/2023] [Indexed: 09/02/2023]
Abstract
Translation affects messenger RNA stability and, in yeast, this is mediated by the Ccr4-Not deadenylation complex. The details of this process in mammals remain unclear. Here, we use cryogenic electron microscopy (cryo-EM) and crosslinking mass spectrometry to show that mammalian CCR4-NOT specifically recognizes ribosomes that are stalled during translation elongation in an in vitro reconstituted system with rabbit and human components. Similar to yeast, mammalian CCR4-NOT inserts a helical bundle of its CNOT3 subunit into the empty E site of the ribosome. Our cryo-EM structure shows that CNOT3 also locks the L1 stalk in an open conformation to inhibit further translation. CCR4-NOT is required for stable association of the nonconstitutive subunit CNOT4, which ubiquitinates the ribosome, likely to signal stalled translation elongation. Overall, our work shows that human CCR4-NOT not only detects but also enforces ribosomal stalling to couple translation and mRNA decay.
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Affiliation(s)
- Eva Absmeier
- MRC Laboratory of Molecular Biology (LMB), Cambridge, UK
- Freie University of Berlin, Berlin, Germany
| | | | | | | | - Juri Rappsilber
- Technical University of Berlin, Chair of Bioanalytics, Berlin, Germany
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
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20
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Höpfler M, Hegde RS. Control of mRNA fate by its encoded nascent polypeptide. Mol Cell 2023; 83:2840-2855. [PMID: 37595554 PMCID: PMC10501990 DOI: 10.1016/j.molcel.2023.07.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 07/03/2023] [Accepted: 07/11/2023] [Indexed: 08/20/2023]
Abstract
Cells tightly regulate mRNA processing, localization, and stability to ensure accurate gene expression in diverse cellular states and conditions. Most of these regulatory steps have traditionally been thought to occur before translation by the action of RNA-binding proteins. Several recent discoveries highlight multiple co-translational mechanisms that modulate mRNA translation, localization, processing, and stability. These mechanisms operate by recognition of the nascent protein, which is necessarily coupled to its encoding mRNA during translation. Hence, the distinctive sequence or structure of a particular nascent chain can recruit recognition factors with privileged access to the corresponding mRNA in an otherwise crowded cellular environment. Here, we draw on both well-established and recent examples to provide a conceptual framework for how cells exploit nascent protein recognition to direct mRNA fate. These mechanisms allow cells to dynamically and specifically regulate their transcriptomes in response to changes in cellular states to maintain protein homeostasis.
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21
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Jain S, Koziej L, Poulis P, Kaczmarczyk I, Gaik M, Rawski M, Ranjan N, Glatt S, Rodnina MV. Modulation of translational decoding by m 6A modification of mRNA. Nat Commun 2023; 14:4784. [PMID: 37553384 PMCID: PMC10409866 DOI: 10.1038/s41467-023-40422-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 07/27/2023] [Indexed: 08/10/2023] Open
Abstract
N6-methyladenosine (m6A) is an abundant, dynamic mRNA modification that regulates key steps of cellular mRNA metabolism. m6A in the mRNA coding regions inhibits translation elongation. Here, we show how m6A modulates decoding in the bacterial translation system using a combination of rapid kinetics, smFRET and single-particle cryo-EM. We show that, while the modification does not impair the initial binding of aminoacyl-tRNA to the ribosome, in the presence of m6A fewer ribosomes complete the decoding process due to the lower stability of the complexes and enhanced tRNA drop-off. The mRNA codon adopts a π-stacked codon conformation that is remodeled upon aminoacyl-tRNA binding. m6A does not exclude canonical codon-anticodon geometry, but favors alternative more dynamic conformations that are rejected by the ribosome. These results highlight how modifications outside the Watson-Crick edge can still interfere with codon-anticodon base pairing and complex recognition by the ribosome, thereby modulating the translational efficiency of modified mRNAs.
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Affiliation(s)
- Sakshi Jain
- Max Planck Institute for Multidisciplinary Sciences, Göttingen, 37077, Germany
| | - Lukasz Koziej
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, 30-387, Poland
| | - Panagiotis Poulis
- Max Planck Institute for Multidisciplinary Sciences, Göttingen, 37077, Germany
| | - Igor Kaczmarczyk
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, 30-387, Poland
- Doctoral School of Exact and Natural Sciences, Jagiellonian University, Krakow, 30-387, Poland
| | - Monika Gaik
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, 30-387, Poland
| | - Michal Rawski
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, 30-387, Poland
- National Synchrotron Radiation Centre SOLARIS, Jagiellonian University, Krakow, 30-387, Poland
| | - Namit Ranjan
- Max Planck Institute for Multidisciplinary Sciences, Göttingen, 37077, Germany
| | - Sebastian Glatt
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, 30-387, Poland.
| | - Marina V Rodnina
- Max Planck Institute for Multidisciplinary Sciences, Göttingen, 37077, Germany.
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22
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Kejiou NS, Ilan L, Aigner S, Luo E, Tonn T, Ozadam H, Lee M, Cole G, Rabano I, Rajakulendran N, Yee BA, Najafabadi H, Moraes T, Angers S, Yeo G, Cenik C, Palazzo A. Pyruvate Kinase M (PKM) binds ribosomes in a poly-ADP ribosylation dependent manner to induce translational stalling. Nucleic Acids Res 2023; 51:6461-6478. [PMID: 37224531 PMCID: PMC10325899 DOI: 10.1093/nar/gkad440] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 05/01/2023] [Accepted: 05/10/2023] [Indexed: 05/26/2023] Open
Abstract
In light of the numerous studies identifying post-transcriptional regulators on the surface of the endoplasmic reticulum (ER), we asked whether there are factors that regulate compartment specific mRNA translation in human cells. Using a proteomic survey of spatially regulated polysome interacting proteins, we identified the glycolytic enzyme Pyruvate Kinase M (PKM) as a cytosolic (i.e. ER-excluded) polysome interactor and investigated how it influences mRNA translation. We discovered that the PKM-polysome interaction is directly regulated by ADP levels-providing a link between carbohydrate metabolism and mRNA translation. By performing enhanced crosslinking immunoprecipitation-sequencing (eCLIP-seq), we found that PKM crosslinks to mRNA sequences that are immediately downstream of regions that encode lysine- and glutamate-enriched tracts. Using ribosome footprint protection sequencing, we found that PKM binding to ribosomes causes translational stalling near lysine and glutamate encoding sequences. Lastly, we observed that PKM recruitment to polysomes is dependent on poly-ADP ribosylation activity (PARylation)-and may depend on co-translational PARylation of lysine and glutamate residues of nascent polypeptide chains. Overall, our study uncovers a novel role for PKM in post-transcriptional gene regulation, linking cellular metabolism and mRNA translation.
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Affiliation(s)
- Nevraj S Kejiou
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Lena Ilan
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Stefan Aigner
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
| | - Enching Luo
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
| | - Tori Tonn
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
| | - Hakan Ozadam
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
| | - Muyoung Lee
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
| | - Gregory B Cole
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Ines Rabano
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
| | | | - Brian A Yee
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
| | - Hamed S Najafabadi
- Department of Human Genetics, McGill University, Montreal, QC, Canada
- McGill University and Genome Quebec Innovation Centre, Montreal, QC, Canada
| | - Trevor F Moraes
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Stephane Angers
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, Canada
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, USA
| | - Can Cenik
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
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23
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Viera Ortiz AP, Cajka G, Olatunji OA, Mikytuck B, Shalem O, Lee EB. Impaired ribosome-associated quality control of C9orf72 arginine-rich dipeptide-repeat proteins. Brain 2023; 146:2897-2912. [PMID: 36516294 PMCID: PMC10316761 DOI: 10.1093/brain/awac479] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 11/05/2022] [Accepted: 12/06/2022] [Indexed: 12/15/2022] Open
Abstract
Protein quality control pathways have evolved to ensure the fidelity of protein synthesis and efficiently clear potentially toxic protein species. Defects in ribosome-associated quality control and its associated factors have been implicated in the accumulation of aberrant proteins and neurodegeneration. C9orf72 repeat-associated non-AUG translation has been suggested to involve inefficient translation elongation, lead to ribosomal pausing and activation of ribosome-associated quality control pathways. However, the role of the ribosome-associated quality control complex in the processing of proteins generated through this non-canonical translation is not well understood. Here we use reporter constructs containing the C9orf72-associated hexanucleotide repeat, ribosome-associated quality control complex deficient cell models and stain for ribosome-associated quality control markers in C9orf72-expansion carrier human tissue to understand its role in dipeptide-repeat protein pathology. Our studies show that canonical ribosome-associated quality control substrates products are efficiently cleared by the ribosome-associated quality control complex in mammalian cells. Furthermore, using stalling reporter constructs, we show that repeats associated with the C9orf72-expansion induce ribosomal stalling when arginine (R)-rich dipeptide-repeat proteins are synthesized in a length-dependent manner. However, despite triggering this pathway, these arginine-rich dipeptide-repeat proteins are not efficiently processed by the core components of the ribosome-associated quality control complex (listerin, nuclear-export mediator factor and valosin containing protein) partly due to lack of lysine residues, which precludes ubiquitination. Deficient processing by this complex may be implicated in C9orf72-expansion associated disease as dipeptide-repeat protein inclusions were observed to be predominantly devoid of ubiquitin and co-localize with nuclear-export mediator factor in mutation carriers' frontal cortex and cerebellum tissue. These findings suggest that impaired processing of these arginine-rich dipeptide-repeat proteins derived from repeat-associated non-AUG translation by the ribosome-associated quality control complex may contribute to protein homeostasis dysregulation observed in C9orf72-expansion amyotrophic lateral sclerosis and frontotemporal degeneration neuropathogenesis.
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Affiliation(s)
- Ashley P Viera Ortiz
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Translational Neuropathology Research Laboratory, Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Gregory Cajka
- Center for Cellular and Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Olamide A Olatunji
- Translational Neuropathology Research Laboratory, Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Bailey Mikytuck
- Translational Neuropathology Research Laboratory, Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ophir Shalem
- Center for Cellular and Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Edward B Lee
- Translational Neuropathology Research Laboratory, Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
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24
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Scavone F, Gumbin S, Da Rosa P, Kopito R. RPL26/uL24 UFMylation is essential for ribosome-associated quality control at the endoplasmic reticulum. Proc Natl Acad Sci U S A 2023; 120:e2220340120. [PMID: 37036982 PMCID: PMC10120006 DOI: 10.1073/pnas.2220340120] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 03/14/2023] [Indexed: 04/12/2023] Open
Abstract
Ribosomes that stall while translating cytosolic proteins are incapacitated by incomplete nascent chains, termed "arrest peptides" (APs) that are destroyed by the ubiquitin proteasome system (UPS) via a process known as the ribosome-associated quality control (RQC) pathway. By contrast, APs on ribosomes that stall while translocating secretory proteins into the endoplasmic reticulum (ER-APs) are shielded from cytosol by the ER membrane and the tightly sealed ribosome-translocon junction (RTJ). How this junction is breached to enable access of cytosolic UPS machinery and 26S proteasomes to translocon- and ribosome-obstructing ER-APs is not known. Here, we show that UPS and RQC-dependent degradation of ER-APs strictly requires conjugation of the ubiquitin-like (Ubl) protein UFM1 to 60S ribosomal subunits at the RTJ. Therefore, UFMylation of translocon-bound 60S subunits modulates the RTJ to promote access of proteasomes and RQC machinery to ER-APs.
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Affiliation(s)
| | - Samantha C. Gumbin
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA94305
| | - Paul A. Da Rosa
- Department of Biology, Stanford University, Stanford, CA94305
| | - Ron R. Kopito
- Department of Biology, Stanford University, Stanford, CA94305
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25
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Wu H, Hegde RS. Mechanism of signal-anchor triage during early steps of membrane protein insertion. Mol Cell 2023; 83:961-973.e7. [PMID: 36764302 PMCID: PMC10155758 DOI: 10.1016/j.molcel.2023.01.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 12/08/2022] [Accepted: 01/18/2023] [Indexed: 02/11/2023]
Abstract
Most membrane proteins use their first transmembrane domain, known as a signal anchor (SA), for co-translational targeting to the endoplasmic reticulum (ER) via the signal recognition particle (SRP). The SA then inserts into the membrane using either the Sec61 translocation channel or the ER membrane protein complex (EMC) insertase. How EMC and Sec61 collaborate to ensure SA insertion in the correct topology is not understood. Using site-specific crosslinking, we detect a pre-insertion SA intermediate adjacent to EMC. This intermediate forms after SA release from SRP but before ribosome transfer to Sec61. The polypeptide's N-terminal tail samples a cytosolic vestibule bordered by EMC3, from where it can translocate across the membrane concomitant with SA insertion. The ribosome then docks on Sec61, which has an opportunity to insert those SAs skipped by EMC. These results suggest that EMC acts between SRP and Sec61 to triage SAs for insertion during membrane protein biogenesis.
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Affiliation(s)
- Haoxi Wu
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
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26
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Scavone F, Gumbin SC, DaRosa PA, Kopito RR. RPL26/uL24 UFMylation is essential for ribosome-associated quality control at the endoplasmic reticulum. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.08.531792. [PMID: 36945571 PMCID: PMC10028864 DOI: 10.1101/2023.03.08.531792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
Ribosomes that stall while translating cytosolic proteins are incapacitated by incomplete nascent chains, termed "arrest peptides" (APs) that are destroyed by the ubiquitin proteasome system (UPS) via a process known as the ribosome-associated quality control (RQC) pathway. By contrast, APs on ribosomes that stall while translocating secretory proteins into the endoplasmic reticulum (ER-APs) are shielded from cytosol by the ER membrane and the tightly sealed ribosome-translocon junction (RTJ). How this junction is breached to enable access of cytosolic UPS machinery and 26S proteasomes to translocon- and ribosome-obstructing ER-APs is not known. Here, we show that UPS and RQC-dependent degradation of ER-APs strictly requires conjugation of the ubiquitin-like (Ubl) protein UFM1 to 60S ribosomal subunits at the RTJ. Therefore, UFMylation of translocon-bound 60S subunits modulates the RTJ to promote access of proteasomes and RQC machinery to ER-APs. Significance Statement UFM1 is a ubiquitin-like protein that is selectively conjugated to the large (60S) subunit of ribosomes bound to the endoplasmic reticulum (ER), but the specific biological function of this modification is unclear. Here, we show that UFMylation facilitates proteasome-mediated degradation of arrest polypeptides (APs) which are generated following splitting of ribosomes that stall during co-translational translocation of secretory proteins into the ER. We propose that UFMylation weakens the tightly sealed ribosome-translocon junction, thereby allowing the cytosolic ubiquitin-proteasome and ribosome-associated quality control machineries to access ER-APs.
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Affiliation(s)
| | - Samantha C Gumbin
- Department of Molecular and Cellular Physiology, Stanford School of Medicine, Stanford CA, 94305
| | - Paul A DaRosa
- Department of Biology, Stanford University, Stanford CA, 94305
| | - Ron R Kopito
- Department of Biology, Stanford University, Stanford CA, 94305
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27
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Faille A, Dent KC, Pellegrino S, Jaako P, Warren AJ. The chemical landscape of the human ribosome at 1.67 Å resolution. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.28.530191. [PMID: 36909531 PMCID: PMC10002709 DOI: 10.1101/2023.02.28.530191] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
The ability of ribosomes to translate the genetic code into protein requires a finely tuned ion and solvent ecosystem. However, the lack of high-resolution structures has precluded accurate positioning of all the functional elements of the ribosome and limited our understanding of the specific role of ribosomal RNA chemical modifications in modulating ribosome function in health and disease. Here, using a new sample preparation methodology based on functionalised pristine graphene-coated grids, we solve the cryo-EM structure of the human large ribosomal subunit to a resolution of 1.67 Å. The accurate assignment of water molecules, magnesium and potassium ions in our model highlights the fundamental biological role of ribosomal RNA methylation in harnessing unconventional carbon-oxygen hydrogen bonds to establish chemical interactions with the environment and fine-tune the functional interplay with tRNA. In addition, the structures of three translational inhibitors bound to the human large ribosomal subunit at better than 2 Å resolution provide mechanistic insights into how three key druggable pockets of the ribosome are targeted and illustrate the potential of this methodology to accelerate high-throughput structure-based design of anti-cancer therapeutics.
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28
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Matsuo Y, Inada T. Co-Translational Quality Control Induced by Translational Arrest. Biomolecules 2023; 13:biom13020317. [PMID: 36830686 PMCID: PMC9953336 DOI: 10.3390/biom13020317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/19/2023] [Accepted: 02/06/2023] [Indexed: 02/11/2023] Open
Abstract
Genetic mutations, mRNA processing errors, and lack of availability of charged tRNAs sometimes slow down or completely stall translating ribosomes. Since an incomplete nascent chain derived from stalled ribosomes may function anomalously, such as by forming toxic aggregates, surveillance systems monitor every step of translation and dispose of such products to prevent their accumulation. Over the past decade, yeast models with powerful genetics and biochemical techniques have contributed to uncovering the mechanism of the co-translational quality control system, which eliminates the harmful products generated from aberrant translation. We here summarize the current knowledge of the molecular mechanism of the co-translational quality control systems in yeast, which eliminate the incomplete nascent chain, improper mRNAs, and faulty ribosomes to maintain cellular protein homeostasis.
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29
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Eisenack TJ, Trentini DB. Ending a bad start: Triggers and mechanisms of co-translational protein degradation. Front Mol Biosci 2023; 9:1089825. [PMID: 36660423 PMCID: PMC9846516 DOI: 10.3389/fmolb.2022.1089825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 12/15/2022] [Indexed: 01/05/2023] Open
Abstract
Proteins are versatile molecular machines that control and execute virtually all cellular processes. They are synthesized in a multilayered process requiring transfer of information from DNA to RNA and finally into polypeptide, with many opportunities for error. In addition, nascent proteins must successfully navigate a complex folding-energy landscape, in which their functional native state represents one of many possible outcomes. Consequently, newly synthesized proteins are at increased risk of misfolding and toxic aggregation. To maintain proteostasis-the state of proteome balance-cells employ a plethora of molecular chaperones that guide proteins along a productive folding pathway and quality control factors that direct misfolded species for degradation. Achieving the correct balance between folding and degradation therefore represents a fundamental task for the proteostasis network. While many chaperones act co-translationally, protein quality control is generally considered to be a post-translational process, as the majority of proteins will only achieve their final native state once translation is completed. Nevertheless, it has been observed that proteins can be ubiquitinated during synthesis. The extent and the relevance of co-translational protein degradation, as well as the underlying molecular mechanisms, remain areas of open investigation. Recent studies made seminal advances in elucidating ribosome-associated quality control processes, and how their loss of function can lead to proteostasis failure and disease. Here, we discuss current understanding of the situations leading to the marking of nascent proteins for degradation before synthesis is completed, and the emerging quality controls pathways engaged in this task in eukaryotic cells. We also highlight the methods used to study co-translational quality control.
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Affiliation(s)
- Tom Joshua Eisenack
- University of Cologne, Faculty of Medicine, University Hospital of Cologne, Center for Molecular Medicine Cologne (CMMC), Cologne, Germany
| | - Débora Broch Trentini
- University of Cologne, Faculty of Medicine, University Hospital of Cologne, Center for Molecular Medicine Cologne (CMMC), Cologne, Germany,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany,*Correspondence: Débora Broch Trentini,
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30
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Leesch F, Lorenzo-Orts L, Pribitzer C, Grishkovskaya I, Roehsner J, Chugunova A, Matzinger M, Roitinger E, Belačić K, Kandolf S, Lin TY, Mechtler K, Meinhart A, Haselbach D, Pauli A. A molecular network of conserved factors keeps ribosomes dormant in the egg. Nature 2023; 613:712-720. [PMID: 36653451 PMCID: PMC7614339 DOI: 10.1038/s41586-022-05623-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 12/02/2022] [Indexed: 01/20/2023]
Abstract
Ribosomes are produced in large quantities during oogenesis and are stored in the egg. However, the egg and early embryo are translationally repressed1-4. Here, using mass spectrometry and cryo-electron microscopy analyses of ribosomes isolated from zebrafish (Danio rerio) and Xenopus laevis eggs and embryos, we provide molecular evidence that ribosomes transition from a dormant state to an active state during the first hours of embryogenesis. Dormant ribosomes are associated with four conserved factors that form two modules, consisting of Habp4-eEF2 and death associated protein 1b (Dap1b) or Dap in complex with eIF5a. Both modules occupy functionally important sites and act together to stabilize ribosomes and repress translation. Dap1b (also known as Dapl1 in mammals) is a newly discovered translational inhibitor that stably inserts into the polypeptide exit tunnel. Addition of recombinant zebrafish Dap1b protein is sufficient to block translation and reconstitute the dormant egg ribosome state in a mammalian translation extract in vitro. Thus, a developmentally programmed, conserved ribosome state has a key role in ribosome storage and translational repression in the egg.
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Affiliation(s)
- Friederike Leesch
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Laura Lorenzo-Orts
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria.
| | - Carina Pribitzer
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | - Irina Grishkovskaya
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | - Josef Roehsner
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Anastasia Chugunova
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | - Manuel Matzinger
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | - Elisabeth Roitinger
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | - Katarina Belačić
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Susanne Kandolf
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | - Tzi-Yang Lin
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Karl Mechtler
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | - Anton Meinhart
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | - David Haselbach
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria.
| | - Andrea Pauli
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria.
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31
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Monem PC, Vidyasagar N, Piatt AL, Sehgal E, Arribere JA. Ubiquitination of stalled ribosomes enables mRNA decay via HBS-1 and NONU-1 in vivo. PLoS Genet 2023; 19:e1010577. [PMID: 36626369 PMCID: PMC9870110 DOI: 10.1371/journal.pgen.1010577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 01/23/2023] [Accepted: 12/18/2022] [Indexed: 01/11/2023] Open
Abstract
As ribosomes translate the genetic code, they can encounter a variety of obstacles that hinder their progress. If ribosomes stall for prolonged times, cells suffer due to the loss of translating ribosomes and the accumulation of aberrant protein products. Thus to protect cells, stalled ribosomes experience a series of reactions to relieve the stall and degrade the offending mRNA, a process known as No-Go mRNA Decay (NGD). While much of the machinery for NGD is known, the precise ordering of events and factors along this pathway has not been tested. Here, we deploy C. elegans to unravel the coordinated events comprising NGD. Utilizing a novel reporter and forward and reverse genetics, we identify the machinery required for NGD. Our subsequent molecular analyses define a functional requirement for ubiquitination on at least two ribosomal proteins (eS10 and uS10), and we show that ribosomes lacking ubiquitination sites on eS10 and uS10 fail to perform NGD in vivo. We show that the nuclease NONU-1 acts after the ubiquitin ligase ZNF-598, and discover a novel requirement for the ribosome rescue factors HBS-1/PELO-1 in mRNA decay via NONU-1. Taken together, our work demonstrates mechanisms by which ribosomes signal to effectors of mRNA repression, and we delineate links between repressive factors working toward a well-defined NGD pathway.
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Affiliation(s)
- Parissa C. Monem
- Department of Molecular, Cell, and Developmental Biology, University of California at Santa Cruz, Santa Cruz, California, United States of America
| | - Nitin Vidyasagar
- Department of Molecular, Cell, and Developmental Biology, University of California at Santa Cruz, Santa Cruz, California, United States of America
| | - Audrey L. Piatt
- Department of Molecular, Cell, and Developmental Biology, University of California at Santa Cruz, Santa Cruz, California, United States of America
| | - Enisha Sehgal
- Department of Molecular, Cell, and Developmental Biology, University of California at Santa Cruz, Santa Cruz, California, United States of America
| | - Joshua A. Arribere
- Department of Molecular, Cell, and Developmental Biology, University of California at Santa Cruz, Santa Cruz, California, United States of America
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32
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Deubiquitinase OTUD1 Resolves Stalled Translation on polyA and Rare Codon Rich mRNAs. Mol Cell Biol 2022; 42:e0026522. [PMID: 36445135 PMCID: PMC9753717 DOI: 10.1128/mcb.00265-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
OTUD1 is a deubiquitinating enzyme involved in many cellular processes including cancer and innate, immune signaling pathways. Here, we perform a proximity labeling-based interactome study that identifies OTUD1 largely present in the translation and RNA metabolism protein complexes. Biochemical analysis validates OTUD1 association with ribosome subunits, elongation factors and the E3 ubiquitin ligase ZNF598 but not with the translation initiation machinery. OTUD1 catalytic activity suppresses polyA triggered ribosome stalling through inhibition of ZNF598-mediated RPS10 ubiquitination and stimulates formation of polysomes. Finally, analysis of gene expression suggests that OTUD1 regulates the stability of rare codon rich mRNAs by antagonizing ZNF598.
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33
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Jürgens L, Wethmar K. The Emerging Role of uORF-Encoded uPeptides and HLA uLigands in Cellular and Tumor Biology. Cancers (Basel) 2022; 14:cancers14246031. [PMID: 36551517 PMCID: PMC9776223 DOI: 10.3390/cancers14246031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/29/2022] [Accepted: 11/30/2022] [Indexed: 12/13/2022] Open
Abstract
Recent technological advances have facilitated the detection of numerous non-canonical human peptides derived from regulatory regions of mRNAs, long non-coding RNAs, and other cryptic transcripts. In this review, we first give an overview of the classification of these novel peptides and summarize recent improvements in their annotation and detection by ribosome profiling, mass spectrometry, and individual experimental analysis. A large fraction of the novel peptides originates from translation at upstream open reading frames (uORFs) that are located within the transcript leader sequence of regular mRNA. In humans, uORF-encoded peptides (uPeptides) have been detected in both healthy and malignantly transformed cells and emerge as important regulators in cellular and immunological pathways. In the second part of the review, we focus on various functional implications of uPeptides. As uPeptides frequently act at the transition of translational regulation and individual peptide function, we describe the mechanistic modes of translational regulation through ribosome stalling, the involvement in cellular programs through protein interaction and complex formation, and their role within the human leukocyte antigen (HLA)-associated immunopeptidome as HLA uLigands. We delineate how malignant transformation may lead to the formation of novel uORFs, uPeptides, or HLA uLigands and explain their potential implication in tumor biology. Ultimately, we speculate on a potential use of uPeptides as peptide drugs and discuss how uPeptides and HLA uLigands may facilitate translational inhibition of oncogenic protein messages and immunotherapeutic approaches in cancer therapy.
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34
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Kriachkov V, Ormsby AR, Kusnadi EP, McWilliam HE, Mintern JD, Amarasinghe SL, Ritchie ME, Furic L, Hatters DM. Arginine-rich C9ORF72 ALS proteins stall ribosomes in a manner distinct from a canonical ribosome-associated quality control substrate. J Biol Chem 2022; 299:102774. [PMID: 36481270 PMCID: PMC9830226 DOI: 10.1016/j.jbc.2022.102774] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 11/23/2022] [Accepted: 11/28/2022] [Indexed: 12/12/2022] Open
Abstract
Hexanucleotide expansion mutations in C9ORF72 are a frequent cause of amyotrophic lateral sclerosis. We previously reported that long arginine-rich dipeptide repeats (DPRs), mimicking abnormal proteins expressed from the hexanucleotide expansion, caused translation stalling when expressed in cell culture models. Whether this stalling provides a mechanism of pathogenicity remains to be determined. Here, we explored the molecular features of DPR-induced stalling and examined whether known mechanisms such as ribosome quality control (RQC) regulate translation elongation on sequences that encode arginine-rich DPRs. We demonstrate that arginine-rich DPRs lead to stalling in a length-dependent manner, with lengths longer than 40 repeats invoking severe translation arrest. Mutational screening of 40×Gly-Xxx DPRs shows that stalling is most pronounced when Xxx is a charged amino acid (Arg, Lys, Glu, or Asp). Through a genome-wide knockout screen, we find that genes regulating stalling on polyadenosine mRNA coding for poly-Lys, a canonical RQC substrate, act differently in the case of arginine-rich DPRs. Indeed, these findings point to a limited scope for natural regulatory responses to resolve the arginine-rich DPR stalls, even though the stalls may be sensed, as evidenced by an upregulation of RQC gene expression. These findings therefore implicate arginine-rich DPR-mediated stalled ribosomes as a source of stress and toxicity and may be a crucial component in pathomechanisms.
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Affiliation(s)
- Viacheslav Kriachkov
- Department of Biochemistry and Pharmacology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Victoria, Australia
| | - Angelique R. Ormsby
- Department of Biochemistry and Pharmacology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Victoria, Australia
| | - Eric P. Kusnadi
- Translational Prostate Cancer Research Laboratory, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia,Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria, Australia
| | - Hamish E.G. McWilliam
- Department of Biochemistry and Pharmacology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Victoria, Australia,Department of Microbiology and Immunology, Peter Doherty Institute of Infection and Immunity, The University of Melbourne, Melbourne, Victoria, Australia
| | - Justine D. Mintern
- Department of Biochemistry and Pharmacology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Victoria, Australia
| | | | - Matthew E. Ritchie
- Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
| | - Luc Furic
- Translational Prostate Cancer Research Laboratory, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia,Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria, Australia,Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute Cancer Program, Monash University, Clayton, Victoria, Australia
| | - Danny M. Hatters
- Department of Biochemistry and Pharmacology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Victoria, Australia,For correspondence: Danny M. Hatters
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35
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Burke PC, Park H, Subramaniam AR. A nascent peptide code for translational control of mRNA stability in human cells. Nat Commun 2022; 13:6829. [PMID: 36369503 PMCID: PMC9652226 DOI: 10.1038/s41467-022-34664-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 11/02/2022] [Indexed: 11/13/2022] Open
Abstract
Stability of eukaryotic mRNAs is associated with their codon, amino acid, and GC content. Yet, coding sequence motifs that predictably alter mRNA stability in human cells remain poorly defined. Here, we develop a massively parallel assay to measure mRNA effects of thousands of synthetic and endogenous coding sequence motifs in human cells. We identify several families of simple dipeptide repeats whose translation triggers mRNA destabilization. Rather than individual amino acids, specific combinations of bulky and positively charged amino acids are critical for the destabilizing effects of dipeptide repeats. Remarkably, dipeptide sequences that form extended β strands in silico and in vitro slowdown ribosomes and reduce mRNA levels in vivo. The resulting nascent peptide code underlies the mRNA effects of hundreds of endogenous peptide sequences in the human proteome. Our work suggests an intrinsic role for the ribosome as a selectivity filter against the synthesis of bulky and aggregation-prone peptides.
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Affiliation(s)
- Phillip C. Burke
- grid.270240.30000 0001 2180 1622Basic Sciences Division and Computational Biology Section of the Public Health Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109 USA ,grid.34477.330000000122986657Department of Microbiology, University of Washington, Seattle, WA 98195 USA
| | - Heungwon Park
- grid.270240.30000 0001 2180 1622Basic Sciences Division and Computational Biology Section of the Public Health Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109 USA
| | - Arvind Rasi Subramaniam
- grid.270240.30000 0001 2180 1622Basic Sciences Division and Computational Biology Section of the Public Health Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109 USA ,grid.34477.330000000122986657Department of Microbiology, University of Washington, Seattle, WA 98195 USA
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36
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A distinct mammalian disome collision interface harbors K63-linked polyubiquitination of uS10 to trigger hRQT-mediated subunit dissociation. Nat Commun 2022; 13:6411. [PMID: 36302773 PMCID: PMC9613687 DOI: 10.1038/s41467-022-34097-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 10/13/2022] [Indexed: 12/25/2022] Open
Abstract
Translational stalling events that result in ribosome collisions induce Ribosome-associated Quality Control (RQC) in order to degrade potentially toxic truncated nascent proteins. For RQC induction, the collided ribosomes are first marked by the Hel2/ZNF598 E3 ubiquitin ligase to recruit the RQT complex for subunit dissociation. In yeast, uS10 is polyubiquitinated by Hel2, whereas eS10 is preferentially monoubiquitinated by ZNF598 in human cells for an unknown reason. Here, we characterize the ubiquitination activity of ZNF598 and its importance for human RQT-mediated subunit dissociation using the endogenous XBP1u and poly(A) translation stallers. Cryo-EM analysis of a human collided disome reveals a distinct composite interface, with substantial differences to yeast collided disomes. Biochemical analysis of collided ribosomes shows that ZNF598 forms K63-linked polyubiquitin chains on uS10, which are decisive for mammalian RQC initiation. The human RQT (hRQT) complex composed only of ASCC3, ASCC2 and TRIP4 dissociates collided ribosomes dependent on the ATPase activity of ASCC3 and the ubiquitin-binding capacity of ASCC2. The hRQT-mediated subunit dissociation requires the K63-linked polyubiquitination of uS10, while monoubiquitination of eS10 or uS10 is not sufficient. Therefore, we conclude that ZNF598 functionally marks collided mammalian ribosomes by K63-linked polyubiquitination of uS10 for the trimeric hRQT complex-mediated subunit dissociation.
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RACK1 Regulates Poxvirus Protein Synthesis Independently of Its Role in Ribosome-Based Stress Signaling. J Virol 2022; 96:e0109322. [PMID: 36098514 PMCID: PMC9517738 DOI: 10.1128/jvi.01093-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Receptor for activated C kinase 1 (RACK1) is a small ribosomal subunit protein that is phosphorylated by vaccinia virus (VacV) to maximize translation of postreplicative (PR) mRNAs that harbor 5' polyA leaders. However, RACK1 is a multifunctional protein that both controls translation directly and acts as a scaffold for signaling to and from the ribosome. This includes stress signaling that is activated by ribosome-associated quality control (RQC) and ribotoxic stress response (RSR) pathways. As VacV infection activates RQC and stress signaling, whether RACK1 influences viral protein synthesis through its effects on translation, signaling, or both remains unclear. Examining the effects of genetic knockout of RACK1 on the phosphorylation of key mitogenic and stress-related kinases, we reveal that loss of RACK1 specifically blunts the activation of c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) at late stages of infection. However, RACK1 was not required for JNK recruitment to ribosomes, and unlike RACK1 knockout, JNK inhibitors had no effect on viral protein synthesis. Moreover, reduced JNK activity during infection in RACK1 knockout cells contrasted with the absolute requirement for RACK1 in RSR-induced JNK phosphorylation. Comparing the effects of RACK1 knockout alongside inhibitors of late stage replication, our data suggest that JNK activation is only indirectly affected by the absence of RACK1 due to reduced viral protein accumulation. Cumulatively, our findings in the context of infection add further support for a model whereby RACK1 plays a specific and direct role in controlling translation of PR viral mRNAs that is independent of its role in ribosome-based stress signaling. IMPORTANCE Receptor for activated C kinase 1 (RACK1) is a multifunctional ribosomal protein that regulates translation directly and mediates signaling to and from the ribosome. While recent work has shown that RACK1 is phosphorylated by vaccinia virus (VacV) to stimulate translation of postreplicative viral mRNAs, whether RACK1 also contributes to VacV replication through its roles in ribosome-based stress signaling remains unclear. Here, we characterize the role of RACK1 in infected cells. In doing so, we find that RACK1 is essential for stress signal activation by ribotoxic stress responses but not by VacV infection. Moreover, although the loss of RACK1 reduces the level of stress-associated JNK activation in infected cells, this is an indirect consequence of RACK1's specific requirement for the synthesis of postreplicative viral proteins, the accumulation of which determines the level of cellular stress. Our findings reveal both the specific role of RACK1 and the complex downstream effects of its control of viral protein synthesis in the context of infection.
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Zheng AJL, Thermou A, Daskalogianni C, Malbert-Colas L, Karakostis K, Le Sénéchal R, Trang Dinh V, Tovar Fernandez MC, Apcher S, Chen S, Blondel M, Fahraeus R. The nascent polypeptide-associated complex (NAC) controls translation initiation in cis by recruiting nucleolin to the encoding mRNA. Nucleic Acids Res 2022; 50:10110-10122. [PMID: 36107769 PMCID: PMC9508830 DOI: 10.1093/nar/gkac751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 09/10/2022] [Indexed: 11/20/2022] Open
Abstract
Protein aggregates and abnormal proteins are toxic and associated with neurodegenerative diseases. There are several mechanisms to help cells get rid of aggregates but little is known on how cells prevent aggregate-prone proteins from being synthesised. The EBNA1 of the Epstein-Barr virus (EBV) evades the immune system by suppressing its own mRNA translation initiation in order to minimize the production of antigenic peptides for the major histocompatibility (MHC) class I pathway. Here we show that the emerging peptide of the disordered glycine–alanine repeat (GAr) within EBNA1 dislodges the nascent polypeptide-associated complex (NAC) from the ribosome. This results in the recruitment of nucleolin to the GAr-encoding mRNA and suppression of mRNA translation initiation in cis. Suppressing NAC alpha (NACA) expression prevents nucleolin from binding to the GAr mRNA and overcomes GAr-mediated translation inhibition. Taken together, these observations suggest that EBNA1 exploits a nascent protein quality control pathway to regulate its own rate of synthesis that is based on sensing the nascent GAr peptide by NAC followed by the recruitment of nucleolin to the GAr-encoding RNA sequence.
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Affiliation(s)
- Alice J L Zheng
- Inserm UMRS 1131, Institut de Génétique Moléculaire, Université de Paris, Hôpital St. Louis , F-75010 Paris , France
| | - Aikaterini Thermou
- Inserm UMRS 1131, Institut de Génétique Moléculaire, Université de Paris, Hôpital St. Louis , F-75010 Paris , France
- ICCVS, University of Gdańsk , Science, ul. Wita Stwosza 63 , 80-308 Gdańsk , Poland
| | - Chrysoula Daskalogianni
- Inserm UMRS 1131, Institut de Génétique Moléculaire, Université de Paris, Hôpital St. Louis , F-75010 Paris , France
- ICCVS, University of Gdańsk , Science, ul. Wita Stwosza 63 , 80-308 Gdańsk , Poland
| | - Laurence Malbert-Colas
- Inserm UMRS 1131, Institut de Génétique Moléculaire, Université de Paris, Hôpital St. Louis , F-75010 Paris , France
| | - Konstantinos Karakostis
- Inserm UMRS 1131, Institut de Génétique Moléculaire, Université de Paris, Hôpital St. Louis , F-75010 Paris , France
| | - Ronan Le Sénéchal
- Inserm UMR 1078, Université de Bretagne Occidentale (UBO), Etablissement Français du Sang (EFS) Bretagne, CHRU Brest , 29200 , Brest , France
| | - Van Trang Dinh
- Inserm UMR 1078, Université de Bretagne Occidentale (UBO), Etablissement Français du Sang (EFS) Bretagne, CHRU Brest , 29200 , Brest , France
| | - Maria C Tovar Fernandez
- Inserm UMRS 1131, Institut de Génétique Moléculaire, Université de Paris, Hôpital St. Louis , F-75010 Paris , France
- ICCVS, University of Gdańsk , Science, ul. Wita Stwosza 63 , 80-308 Gdańsk , Poland
| | - Sébastien Apcher
- Institut Gustave Roussy, Université Paris Sud, Unité 1015 département d’immunologie , 114, rue Edouard Vaillant , 94805 Villejuif , France
| | - Sa Chen
- Department of Medical Biosciences, Building 6M, Umeå University , 901 85 Umeå , Sweden
| | - Marc Blondel
- Inserm UMR 1078, Université de Bretagne Occidentale (UBO), Etablissement Français du Sang (EFS) Bretagne, CHRU Brest , 29200 , Brest , France
| | - Robin Fahraeus
- Inserm UMRS 1131, Institut de Génétique Moléculaire, Université de Paris, Hôpital St. Louis , F-75010 Paris , France
- Department of Medical Biosciences, Building 6M, Umeå University , 901 85 Umeå , Sweden
- RECAMO, Masaryk Memorial Cancer Institute , Zluty kopec 7 , 65653 Brno , Czech Republic
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39
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Sfera A, Hazan S, Anton JJ, Sfera DO, Andronescu CV, Sasannia S, Rahman L, Kozlakidis Z. Psychotropic drugs interaction with the lipid nanoparticle of COVID-19 mRNA therapeutics. Front Pharmacol 2022; 13:995481. [PMID: 36160443 PMCID: PMC9503827 DOI: 10.3389/fphar.2022.995481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 08/09/2022] [Indexed: 11/18/2022] Open
Abstract
The messenger RNA (mRNA) vaccines for COVID-19, Pfizer-BioNTech and Moderna, were authorized in the US on an emergency basis in December of 2020. The rapid distribution of these therapeutics around the country and the world led to millions of people being vaccinated in a short time span, an action that decreased hospitalization and death but also heightened the concerns about adverse effects and drug-vaccine interactions. The COVID-19 mRNA vaccines are of particular interest as they form the vanguard of a range of other mRNA therapeutics that are currently in the development pipeline, focusing both on infectious diseases as well as oncological applications. The Vaccine Adverse Event Reporting System (VAERS) has gained additional attention during the COVID-19 pandemic, specifically regarding the rollout of mRNA therapeutics. However, for VAERS, absence of a reporting platform for drug-vaccine interactions left these events poorly defined. For example, chemotherapy, anticonvulsants, and antimalarials were documented to interfere with the mRNA vaccines, but much less is known about the other drugs that could interact with these therapeutics, causing adverse events or decreased efficacy. In addition, SARS-CoV-2 exploitation of host cytochrome P450 enzymes, reported in COVID-19 critical illness, highlights viral interference with drug metabolism. For example, patients with severe psychiatric illness (SPI) in treatment with clozapine often displayed elevated drug levels, emphasizing drug-vaccine interaction.
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Affiliation(s)
- Adonis Sfera
- Patton State Hospital, San Bernardino, CA, United States
- Department of Psychiatry, University of California, Riverside, Riverside, CA, United States
| | - Sabine Hazan
- Department of Psychiatry, University of California, Riverside, Riverside, CA, United States
| | - Jonathan J. Anton
- Patton State Hospital, San Bernardino, CA, United States
- Department of Biology, California Baptist University, Riverside, CA, United States
| | - Dan O. Sfera
- Patton State Hospital, San Bernardino, CA, United States
| | | | | | - Leah Rahman
- Department of Medicine, University of Oregon, Eugene, OR, United States
| | - Zisis Kozlakidis
- International Agency For Research On Cancer (IARC), Lyon, France
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40
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mRNA and tRNA modification states influence ribosome speed and frame maintenance during poly(lysine) peptide synthesis. J Biol Chem 2022; 298:102039. [PMID: 35595100 PMCID: PMC9207662 DOI: 10.1016/j.jbc.2022.102039] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 04/27/2022] [Accepted: 04/28/2022] [Indexed: 12/16/2022] Open
Abstract
Ribosome speed is dictated by multiple factors including substrate availability, cellular conditions, and product (peptide) formation. Translation slows during the synthesis of cationic peptide sequences, potentially influencing the expression of thousands of proteins. Available evidence suggests that ionic interactions between positively charged nascent peptides and the negatively charged ribosome exit tunnel impede translation. However, this hypothesis was difficult to test directly because of inability to decouple the contributions of amino acid charge from mRNA sequence and tRNA identity/abundance in cells. Furthermore, it is unclear if other components of the translation system central to ribosome function (e.g., RNA modification) influence the speed and accuracy of positively charged peptide synthesis. In this study, we used a fully reconstituted Escherichia coli translation system to evaluate the effects of peptide charge, mRNA sequence, and RNA modification status on the translation of lysine-rich peptides. Comparison of translation reactions on poly(lysine)-encoding mRNAs conducted with either Lys-tRNALys or Val-tRNALys reveals that that amino acid charge, while important, only partially accounts for slowed translation on these transcripts. We further find that in addition to peptide charge, mRNA sequence and both tRNA and mRNA modification status influence the rates of amino acid addition and the ribosome’s ability to maintain frame (instead of entering the −2, −1, and +1 frames) during poly(lysine) peptide synthesis. Our observations lead us to expand the model for explaining how the ribosome slows during poly(lysine) peptide synthesis and suggest that posttranscriptional RNA modifications can provide cells a mechanism to precisely control ribosome movements along an mRNA.
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41
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Multi-omics approach reveals posttranscriptionally regulated genes are essential for human pluripotent stem cells. iScience 2022; 25:104289. [PMID: 35573189 PMCID: PMC9097716 DOI: 10.1016/j.isci.2022.104289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 04/01/2022] [Accepted: 04/20/2022] [Indexed: 11/20/2022] Open
Abstract
The effects of transcription factors on the maintenance and differentiation of human-induced or embryonic pluripotent stem cells (iPSCs/ESCs) have been well studied. However, the importance of posttranscriptional regulatory mechanisms, which cause the quantitative dissociation of mRNA and protein expression, has not been explored in detail. Here, by combining transcriptome and proteome profiling, we identified 228 posttranscriptionally regulated genes with strict upregulation of the protein level in iPSCs/ESCs. Among them, we found 84 genes were vital for the survival of iPSCs and HDFs, including 20 genes that were specifically necessary for iPSC survival. These 20 proteins were upregulated only in iPSCs/ESCs and not in differentiated cells derived from the three germ layers. Although there are still unknown mechanisms that downregulate protein levels in HDFs, these results reveal that posttranscriptionally regulated genes have a crucial role in iPSC survival. The posttranscriptionally regulated 20 genes are necessary for iPSC survival The proteins of HSPA8, EIF3D, and NCBP2 are quickly degraded in HDFs mRNA localization affects the protein amounts in most of the 20 genes Translation is repressed in HDFs despite mRNA binding to ribosomes
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42
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Stoneley M, Harvey RF, Mulroney TE, Mordue R, Jukes-Jones R, Cain K, Lilley KS, Sawarkar R, Willis AE. Unresolved stalled ribosome complexes restrict cell-cycle progression after genotoxic stress. Mol Cell 2022; 82:1557-1572.e7. [PMID: 35180429 PMCID: PMC9098122 DOI: 10.1016/j.molcel.2022.01.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 01/24/2022] [Accepted: 01/24/2022] [Indexed: 01/01/2023]
Abstract
During the translation surveillance mechanism known as ribosome-associated quality control, the ASC-1 complex (ASCC) disassembles ribosomes stalled on the mRNA. Here, we show that there are two distinct classes of stalled ribosome. Ribosomes stalled by translation elongation inhibitors or methylated mRNA are short lived in human cells because they are split by the ASCC. In contrast, although ultraviolet light and 4-nitroquinoline 1-oxide induce ribosome stalling by damaging mRNA, and the ASCC is recruited to these stalled ribosomes, we found that they are refractory to the ASCC. Consequently, unresolved UV- and 4NQO-stalled ribosomes persist in human cells. We show that ribosome stalling activates cell-cycle arrest, partly through ZAK-p38MAPK signaling, and that this cell-cycle delay is prolonged when the ASCC cannot resolve stalled ribosomes. Thus, we propose that the sensitivity of stalled ribosomes to the ASCC influences the kinetics of stall resolution, which in turn controls the adaptive stress response.
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Affiliation(s)
- Mark Stoneley
- MRC Toxicology Unit, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK.
| | - Robert F Harvey
- MRC Toxicology Unit, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
| | - Thomas E Mulroney
- MRC Toxicology Unit, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
| | - Ryan Mordue
- MRC Toxicology Unit, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
| | - Rebekah Jukes-Jones
- MRC Toxicology Unit, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
| | - Kelvin Cain
- MRC Toxicology Unit, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
| | - Kathryn S Lilley
- Cambridge Centre for Proteomics, Cambridge Systems Biology Centre, Department of Biochemistry, University of Cambridge, Cambridge CB2 1QR, UK
| | - Ritwick Sawarkar
- MRC Toxicology Unit, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
| | - Anne E Willis
- MRC Toxicology Unit, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK.
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43
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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: 46] [Impact Index Per Article: 23.0] [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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44
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Kolář MH, Nagy G, Kunkel J, Vaiana SM, Bock LV, Grubmüller H. Folding of VemP into translation-arresting secondary structure is driven by the ribosome exit tunnel. Nucleic Acids Res 2022; 50:2258-2269. [PMID: 35150281 PMCID: PMC8887479 DOI: 10.1093/nar/gkac038] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 11/30/2021] [Accepted: 01/25/2022] [Indexed: 01/09/2023] Open
Abstract
The ribosome is a fundamental biomolecular complex that synthesizes proteins in cells. Nascent proteins emerge from the ribosome through a tunnel, where they may interact with the tunnel walls or small molecules such as antibiotics. These interactions can cause translational arrest with notable physiological consequences. Here, we studied the arrest caused by the regulatory peptide VemP, which is known to form α-helices inside the ribosome tunnel near the peptidyl transferase center under specific conditions. We used all-atom molecular dynamics simulations of the entire ribosome and circular dichroism spectroscopy to study the driving forces of helix formation and how VemP causes the translational arrest. To that aim, we compared VemP dynamics in the ribosome tunnel with its dynamics in solution. We show that the VemP peptide has a low helical propensity in water and that the propensity is higher in mixtures of water and trifluorethanol. We propose that helix formation within the ribosome is driven by the interactions of VemP with the tunnel and that a part of VemP acts as an anchor. This anchor might slow down VemP progression through the tunnel enabling α-helix formation, which causes the elongation arrest.
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Affiliation(s)
- Michal H Kolář
- Department of Theoretical and Computational Biophysics, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 370 77 Göttingen, Germany.,Department of Physical Chemistry, University of Chemistry and Technology in Prague, Technická 5, 166 28 Prague, Czech Republic
| | - Gabor Nagy
- Department of Theoretical and Computational Biophysics, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 370 77 Göttingen, Germany
| | - John Kunkel
- Department of Physics and Center for Biological Physics, Arizona State University, Tempe, AZ 85287, USA
| | - Sara M Vaiana
- Department of Physics and Center for Biological Physics, Arizona State University, Tempe, AZ 85287, USA
| | - Lars V Bock
- Department of Theoretical and Computational Biophysics, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 370 77 Göttingen, Germany
| | - Helmut Grubmüller
- Department of Theoretical and Computational Biophysics, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 370 77 Göttingen, Germany
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45
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Dörner K, Badertscher L, Horváth B, Hollandi R, Molnár C, Fuhrer T, Meier R, Sárazová M, van den Heuvel J, Zamboni N, Horvath P, Kutay U. Genome-wide RNAi screen identifies novel players in human 60S subunit biogenesis including key enzymes of polyamine metabolism. Nucleic Acids Res 2022; 50:2872-2888. [PMID: 35150276 PMCID: PMC8934630 DOI: 10.1093/nar/gkac072] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 01/18/2022] [Accepted: 01/25/2022] [Indexed: 12/19/2022] Open
Abstract
Ribosome assembly is an essential process that is linked to human congenital diseases and tumorigenesis. While great progress has been made in deciphering mechanisms governing ribosome biogenesis in eukaryotes, an inventory of factors that support ribosome synthesis in human cells is still missing, in particular regarding the maturation of the large 60S subunit. Here, we performed a genome-wide RNAi screen using an imaging-based, single cell assay to unravel the cellular machinery promoting 60S subunit assembly in human cells. Our screen identified a group of 310 high confidence factors. These highlight the conservation of the process across eukaryotes and reveal the intricate connectivity of 60S subunit maturation with other key cellular processes, including splicing, translation, protein degradation, chromatin organization and transcription. Intriguingly, we also identified a cluster of hits comprising metabolic enzymes of the polyamine synthesis pathway. We demonstrate that polyamines, which have long been used as buffer additives to support ribosome assembly in vitro, are required for 60S maturation in living cells. Perturbation of polyamine metabolism results in early defects in 60S but not 40S subunit maturation. Collectively, our data reveal a novel function for polyamines in living cells and provide a rich source for future studies on ribosome synthesis.
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Affiliation(s)
- Kerstin Dörner
- Institute of Biochemistry, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland.,Molecular Life Sciences Ph.D. Program, 8057 Zurich, Switzerland
| | - Lukas Badertscher
- Institute of Biochemistry, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland.,Molecular Life Sciences Ph.D. Program, 8057 Zurich, Switzerland
| | - Bianka Horváth
- Institute of Biochemistry, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland.,Molecular Life Sciences Ph.D. Program, 8057 Zurich, Switzerland
| | - Réka Hollandi
- Synthetic and Systems Biology Unit, Biological Research Center, 6726 Szeged, Hungary
| | - Csaba Molnár
- Synthetic and Systems Biology Unit, Biological Research Center, 6726 Szeged, Hungary
| | - Tobias Fuhrer
- Institute of Molecular Systems Biology, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland
| | - Roger Meier
- ScopeM, ETH Zürich, 8093 Zürich, Switzerland
| | - Marie Sárazová
- Institute of Biochemistry, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Jasmin van den Heuvel
- Institute of Biochemistry, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Nicola Zamboni
- Institute of Molecular Systems Biology, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland
| | - Peter Horvath
- Synthetic and Systems Biology Unit, Biological Research Center, 6726 Szeged, Hungary.,Institute for Molecular Medicine Finland, University of Helsinki, 00014 Helsinki, Finland
| | - Ulrike Kutay
- Institute of Biochemistry, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
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46
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Roles of mRNA poly(A) tails in regulation of eukaryotic gene expression. Nat Rev Mol Cell Biol 2022; 23:93-106. [PMID: 34594027 PMCID: PMC7614307 DOI: 10.1038/s41580-021-00417-y] [Citation(s) in RCA: 186] [Impact Index Per Article: 93.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2021] [Indexed: 02/06/2023]
Abstract
In eukaryotes, poly(A) tails are present on almost every mRNA. Early experiments led to the hypothesis that poly(A) tails and the cytoplasmic polyadenylate-binding protein (PABPC) promote translation and prevent mRNA degradation, but the details remained unclear. More recent data suggest that the role of poly(A) tails is much more complex: poly(A)-binding protein can stimulate poly(A) tail removal (deadenylation) and the poly(A) tails of stable, highly translated mRNAs at steady state are much shorter than expected. Furthermore, the rate of translation elongation affects deadenylation. Consequently, the interplay between poly(A) tails, PABPC, translation and mRNA decay has a major role in gene regulation. In this Review, we discuss recent work that is revolutionizing our understanding of the roles of poly(A) tails in the cytoplasm. Specifically, we discuss the roles of poly(A) tails in translation and control of mRNA stability and how poly(A) tails are removed by exonucleases (deadenylases), including CCR4-NOT and PAN2-PAN3. We also discuss how deadenylation rate is determined, the integration of deadenylation with other cellular processes and the function of PABPC. We conclude with an outlook for the future of research in this field.
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47
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Jaquet V, Wallerich S, Voegeli S, Túrós D, Viloria EC, Becskei A. Determinants of the temperature adaptation of mRNA degradation. Nucleic Acids Res 2022; 50:1092-1110. [PMID: 35018460 PMCID: PMC8789057 DOI: 10.1093/nar/gkab1261] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 12/04/2021] [Accepted: 12/09/2021] [Indexed: 12/26/2022] Open
Abstract
The rate of chemical reactions increases proportionally with temperature, but the interplay of biochemical reactions permits deviations from this relation and adaptation. The degradation of individual mRNAs in yeast increased to varying degrees with temperature. We examined how these variations are influenced by the translation and codon composition of mRNAs. We developed a method that revealed the existence of a neutral half-life above which mRNAs are stabilized by translation but below which they are destabilized. The proportion of these two mRNA subpopulations remained relatively constant under different conditions, even with slow cell growth due to nutrient limitation, but heat shock reduced the proportion of translationally stabilized mRNAs. At the same time, the degradation of these mRNAs was partially temperature-compensated through Upf1, the mediator of nonsense-mediated decay. Compensation was also promoted by some asparagine and serine codons, whereas tyrosine codons promote temperature sensitization. These codons play an important role in the degradation of mRNAs encoding key cell membrane and cell wall proteins, which promote cell integrity.
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Affiliation(s)
- Vincent Jaquet
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
| | - Sandrine Wallerich
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
| | - Sylvia Voegeli
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
| | - Demeter Túrós
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
| | - Eduardo C Viloria
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
| | - Attila Becskei
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
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48
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Xiao L, Jun YW, Kool ET. DNA Tiling Enables Precise Acylation‐Based Labeling and Control of mRNA. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202112106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Lu Xiao
- Department of Chemistry Stanford University Stanford CA 94305 USA
| | - Yong Woong Jun
- Department of Chemistry Stanford University Stanford CA 94305 USA
| | - Eric T. Kool
- Department of Chemistry Stanford University Stanford CA 94305 USA
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49
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Xiao L, Jun YW, Kool ET. DNA Tiling Enables Precise Acylation-Based Labeling and Control of mRNA. Angew Chem Int Ed Engl 2021; 60:26798-26805. [PMID: 34624169 PMCID: PMC8649056 DOI: 10.1002/anie.202112106] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/04/2021] [Indexed: 12/15/2022]
Abstract
Methods for the site-selective labeling of long, native RNAs are needed for studying mRNA biology and future therapies. Current approaches involve engineering RNA sequences, which may alter folding, or are limited to specific sequences or bases. Here, we describe a versatile strategy for mRNA conjugation via a novel DNA-tiling approach. The method, TRAIL, exploits a pool of "protector" oligodeoxynucleotides to hybridize and block the mRNA, combined with an "inducer" DNA that extrudes a reactive RNA loop for acylation at a predetermined site. Using TRAIL, an azido-acylimidazole reagent was employed for labeling and controlling RNA for multiple applications in vitro and in cells, including analysis of RNA-binding proteins, imaging mRNA in cells, and analysis and control of translation. The TRAIL approach offers an efficient and accessible way to label and manipulate RNAs of virtually any length or origin without altering native sequence.
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Affiliation(s)
- Lu Xiao
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
| | - Yong Woong Jun
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
| | - Eric T Kool
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
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50
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Shen L, Su Z, Yang K, Wu C, Becker T, Bell-Pedersen D, Zhang J, Sachs MS. Structure of the translating Neurospora ribosome arrested by cycloheximide. Proc Natl Acad Sci U S A 2021; 118:e2111862118. [PMID: 34815343 PMCID: PMC8640747 DOI: 10.1073/pnas.2111862118] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/11/2021] [Indexed: 11/18/2022] Open
Abstract
Ribosomes translate RNA into proteins. The protein synthesis inhibitor cycloheximide (CHX) is widely used to inhibit eukaryotic ribosomes engaged in translation elongation. However, the lack of structural data for actively translating polyribosomes stalled by CHX leaves unanswered the question of which elongation step is inhibited. We elucidated CHX's mechanism of action based on the cryo-electron microscopy structure of actively translating Neurospora crassa ribosomes bound with CHX at 2.7-Å resolution. The ribosome structure from this filamentous fungus contains clearly resolved ribosomal protein eL28, like higher eukaryotes but unlike budding yeast, which lacks eL28. Despite some differences in overall structures, the ribosomes from Neurospora, yeast, and humans all contain a highly conserved CHX binding site. We also sequenced classic Neurospora CHX-resistant alleles. These mutations, including one at a residue not previously observed to affect CHX resistance in eukaryotes, were in the large subunit proteins uL15 and eL42 that are part of the CHX-binding pocket. In addition to A-site transfer RNA (tRNA), P-site tRNA, messenger RNA, and CHX that are associated with the translating N. crassa ribosome, spermidine is present near the CHX binding site close to the E site on the large subunit. The tRNAs in the peptidyl transferase center are in the A/A site and the P/P site. The nascent peptide is attached to the A-site tRNA and not to the P-site tRNA. The structural and functional data obtained show that CHX arrests the ribosome in the classical PRE translocation state and does not interfere with A-site reactivity.
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Affiliation(s)
- Lunda Shen
- Department of Biology, Texas A&M University, College Station, TX 77843
| | - Zhaoming Su
- Department of Bioengineering, Stanford University, Stanford, CA 94305
| | - Kailu Yang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843
| | - Cheng Wu
- Department of Biology, Texas A&M University, College Station, TX 77843
| | - Thomas Becker
- Department of Biochemistry, Gene Center, Ludwig-Maximilians University Munich, 80539 Munich, Germany
| | | | - Junjie Zhang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843
| | - Matthew S Sachs
- Department of Biology, Texas A&M University, College Station, TX 77843;
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