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Monroe J, Eyler DE, Mitchell L, Deb I, Bojanowski A, Srinivas P, Dunham CM, Roy B, Frank AT, Koutmou KS. N1-Methylpseudouridine and pseudouridine modifications modulate mRNA decoding during translation. Nat Commun 2024; 15:8119. [PMID: 39284850 PMCID: PMC11405884 DOI: 10.1038/s41467-024-51301-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 08/02/2024] [Indexed: 09/20/2024] Open
Abstract
The ribosome utilizes hydrogen bonding between mRNA codons and aminoacyl-tRNAs to ensure rapid and accurate protein production. Chemical modification of mRNA nucleobases can adjust the strength and pattern of this hydrogen bonding to alter protein synthesis. We investigate how the N1-methylpseudouridine (m1Ψ) modification, commonly incorporated into therapeutic and vaccine mRNA sequences, influences the speed and fidelity of translation. We find that m1Ψ does not substantially change the rate constants for amino acid addition by cognate tRNAs or termination by release factors. However, we also find that m1Ψ can subtly modulate the fidelity of amino acid incorporation in a codon-position and tRNA dependent manner in vitro and in human cells. Our computational modeling shows that altered energetics of mRNA:tRNA interactions largely account for the context dependence of the low levels of miscoding we observe on Ψ and m1Ψ containing codons. The outcome of translation on modified mRNA bases is thus governed by the sequence context in which they occur.
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Affiliation(s)
- Jeremy Monroe
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Daniel E Eyler
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Lili Mitchell
- RNA and Genome Editing, New England Biolabs Inc., Ipswich, MA, USA
| | - Indrajit Deb
- Department of Biophysics, University of Michigan, Ann Arbor, MI, USA
| | | | - Pooja Srinivas
- Department of Chemistry, Emory University, Atlanta, GA, USA
| | | | - Bijoyita Roy
- RNA and Genome Editing, New England Biolabs Inc., Ipswich, MA, USA
| | - Aaron T Frank
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
- Department of Biophysics, University of Michigan, Ann Arbor, MI, USA
- Computational Chemistry, Arrakis Therapeutics, Waltham, MA, USA
| | - Kristin S Koutmou
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA.
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2
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Jones JD, Franco MK, Giles RN, Eyler DE, Tardu M, Smith TJ, Snyder LR, Polikanov YS, Kennedy RT, Niederer RO, Koutmou KS. Conserved 5-methyluridine tRNA modification modulates ribosome translocation. Proc Natl Acad Sci U S A 2024; 121:e2401743121. [PMID: 39159370 PMCID: PMC11363252 DOI: 10.1073/pnas.2401743121] [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: 01/26/2024] [Accepted: 06/05/2024] [Indexed: 08/21/2024] Open
Abstract
While the centrality of posttranscriptional modifications to RNA biology has long been acknowledged, the function of the vast majority of modified sites remains to be discovered. Illustrative of this, there is not yet a discrete biological role assigned for one of the most highly conserved modifications, 5-methyluridine at position 54 in tRNAs (m5U54). Here, we uncover contributions of m5U54 to both tRNA maturation and protein synthesis. Our mass spectrometry analyses demonstrate that cells lacking the enzyme that installs m5U in the T-loop (TrmA in Escherichia coli, Trm2 in Saccharomyces cerevisiae) exhibit altered tRNA modification patterns. Furthermore, m5U54-deficient tRNAs are desensitized to small molecules that prevent translocation in vitro. This finding is consistent with our observations that relative to wild-type cells, trm2Δ cell growth and transcriptome-wide gene expression are less perturbed by translocation inhibitors. Together our data suggest a model in which m5U54 acts as an important modulator of tRNA maturation and translocation of the ribosome during protein synthesis.
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Affiliation(s)
- Joshua D. Jones
- Department of Chemistry, University of Michigan, Ann Arbor, MI48109
| | - Monika K. Franco
- Program in Chemical Biology, University of Michigan, Ann Arbor, MI48109
| | - Rachel N. Giles
- Department of Chemistry, University of Michigan, Ann Arbor, MI48109
| | - Daniel E. Eyler
- Department of Chemistry, University of Michigan, Ann Arbor, MI48109
| | - Mehmet Tardu
- Department of Chemistry, University of Michigan, Ann Arbor, MI48109
| | - Tyler J. Smith
- Department of Chemistry, University of Michigan, Ann Arbor, MI48109
| | - Laura R. Snyder
- Department of Chemistry, University of Michigan, Ann Arbor, MI48109
| | - Yury S. Polikanov
- Department of Biological Sciences, University of Illinois, Chicago, IL60607
| | | | - Rachel O. Niederer
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI48109
| | - Kristin S. Koutmou
- Department of Chemistry, University of Michigan, Ann Arbor, MI48109
- Program in Chemical Biology, University of Michigan, Ann Arbor, MI48109
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI48109
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3
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Jones JD, Franco MK, Tardu M, Smith TJ, Snyder LR, Eyler DE, Polikanov Y, Kennedy RT, Niederer RO, Koutmou KS. Conserved 5-methyluridine tRNA modification modulates ribosome translocation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.12.566704. [PMID: 37986750 PMCID: PMC10659410 DOI: 10.1101/2023.11.12.566704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
While the centrality of post-transcriptional modifications to RNA biology has long been acknowledged, the function of the vast majority of modified sites remains to be discovered. Illustrative of this, there is not yet a discrete biological role assigned for one the most highly conserved modifications, 5-methyluridine at position 54 in tRNAs (m 5 U54). Here, we uncover contributions of m 5 U54 to both tRNA maturation and protein synthesis. Our mass spectrometry analyses demonstrate that cells lacking the enzyme that installs m 5 U in the T-loop (TrmA in E. coli , Trm2 in S. cerevisiae ) exhibit altered tRNA modifications patterns. Furthermore, m 5 U54 deficient tRNAs are desensitized to small molecules that prevent translocation in vitro. This finding is consistent with our observations that, relative to wild-type cells, trm2 Δ cell growth and transcriptome-wide gene expression are less perturbed by translocation inhibitors. Together our data suggest a model in which m 5 U54 acts as an important modulator of tRNA maturation and translocation of the ribosome during protein synthesis.
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Jones JD, Franco MK, Smith TJ, Snyder LR, Anders AG, Ruotolo BT, Kennedy RT, Koutmou KS. Methylated guanosine and uridine modifications in S. cerevisiae mRNAs modulate translation elongation. RSC Chem Biol 2023; 4:363-378. [PMID: 37181630 PMCID: PMC10170649 DOI: 10.1039/d2cb00229a] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 01/15/2023] [Indexed: 02/22/2023] Open
Abstract
Chemical modifications to protein encoding messenger RNAs (mRNAs) influence their localization, translation, and stability within cells. Over 15 different types of mRNA modifications have been observed by sequencing and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) approaches. While LC-MS/MS is arguably the most essential tool available for studying analogous protein post-translational modifications, the high-throughput discovery and quantitative characterization of mRNA modifications by LC-MS/MS has been hampered by the difficulty of obtaining sufficient quantities of pure mRNA and limited sensitivities for modified nucleosides. We have overcome these challenges by improving the mRNA purification and LC-MS/MS pipelines. The methodologies we developed result in no detectable non-coding RNA modifications signals in our purified mRNA samples, quantify 50 ribonucleosides in a single analysis, and provide the lowest limit of detection reported for ribonucleoside modification LC-MS/MS analyses. These advancements enabled the detection and quantification of 13 S. cerevisiae mRNA ribonucleoside modifications and reveal the presence of four new S. cerevisiae mRNA modifications at low to moderate levels (1-methyguanosine, N2-methylguanosine, N2,N2-dimethylguanosine, and 5-methyluridine). We identified four enzymes that incorporate these modifications into S. cerevisiae mRNAs (Trm10, Trm11, Trm1, and Trm2, respectively), though our results suggest that guanosine and uridine nucleobases are also non-enzymatically methylated at low levels. Regardless of whether they are incorporated in a programmed manner or as the result of RNA damage, we reasoned that the ribosome will encounter the modifications that we detect in cells. To evaluate this possibility, we used a reconstituted translation system to investigate the consequences of modifications on translation elongation. Our findings demonstrate that the introduction of 1-methyguanosine, N2-methylguanosine and 5-methyluridine into mRNA codons impedes amino acid addition in a position dependent manner. This work expands the repertoire of nucleoside modifications that the ribosome must decode in S. cerevisiae. Additionally, it highlights the challenge of predicting the effect of discrete modified mRNA sites on translation de novo because individual modifications influence translation differently depending on mRNA sequence context.
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Affiliation(s)
- Joshua D Jones
- Department of Chemistry, University of Michigan, 930 N University Ann Arbor MI 48109 USA +1-734-764-5650
| | - Monika K Franco
- Program in Chemical Biology, University of Michigan, 930 N University Ann Arbor MI 48109 USA
| | - Tyler J Smith
- Department of Chemistry, University of Michigan, 930 N University Ann Arbor MI 48109 USA +1-734-764-5650
| | - Laura R Snyder
- Department of Chemistry, University of Michigan, 930 N University Ann Arbor MI 48109 USA +1-734-764-5650
| | - Anna G Anders
- Department of Chemistry, University of Michigan, 930 N University Ann Arbor MI 48109 USA +1-734-764-5650
| | - Brandon T Ruotolo
- Department of Chemistry, University of Michigan, 930 N University Ann Arbor MI 48109 USA +1-734-764-5650
| | - Robert T Kennedy
- Department of Chemistry, University of Michigan, 930 N University Ann Arbor MI 48109 USA +1-734-764-5650
- Program in Chemical Biology, University of Michigan, 930 N University Ann Arbor MI 48109 USA
| | - Kristin S Koutmou
- Department of Chemistry, University of Michigan, 930 N University Ann Arbor MI 48109 USA +1-734-764-5650
- Program in Chemical Biology, University of Michigan, 930 N University Ann Arbor MI 48109 USA
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Wright SE, Rodriguez CM, Monroe J, Xing J, Krans A, Flores BN, Barsur V, Ivanova MI, Koutmou KS, Barmada SJ, Todd PK. CGG repeats trigger translational frameshifts that generate aggregation-prone chimeric proteins. Nucleic Acids Res 2022; 50:8674-8689. [PMID: 35904811 PMCID: PMC9410890 DOI: 10.1093/nar/gkac626] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 07/13/2022] [Indexed: 11/25/2022] Open
Abstract
CGG repeat expansions in the FMR1 5’UTR cause the neurodegenerative disease Fragile X-associated tremor/ataxia syndrome (FXTAS). These repeats form stable RNA secondary structures that support aberrant translation in the absence of an AUG start codon (RAN translation), producing aggregate-prone peptides that accumulate within intranuclear neuronal inclusions and contribute to neurotoxicity. Here, we show that the most abundant RAN translation product, FMRpolyG, is markedly less toxic when generated from a construct with a non-repetitive alternating codon sequence in place of the CGG repeat. While exploring the mechanism of this differential toxicity, we observed a +1 translational frameshift within the CGG repeat from the arginine to glycine reading frame. Frameshifts occurred within the first few translated repeats and were triggered predominantly by RNA sequence and structural features. Short chimeric R/G peptides form aggregates distinct from those formed by either pure arginine or glycine, and these chimeras induce toxicity in cultured rodent neurons. Together, this work suggests that CGG repeats support translational frameshifting and that chimeric RAN translated peptides may contribute to CGG repeat-associated toxicity in FXTAS and related disorders.
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Affiliation(s)
- Shannon E Wright
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA.,Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - Caitlin M Rodriguez
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA.,Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI 48109, USA.,Department of Genetics, Stanford University School of Medicine, Stanford, CA 84305, USA
| | - Jeremy Monroe
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jiazheng Xing
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Amy Krans
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA.,VA Ann Arbor Healthcare System, Ann Arbor, MI 48105, USA
| | - Brittany N Flores
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA.,Cellular and Molecular Biology Graduate Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - Venkatesha Barsur
- Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Magdalena I Ivanova
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA.,Biophysics Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - Kristin S Koutmou
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Sami J Barmada
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Peter K Todd
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA.,VA Ann Arbor Healthcare System, Ann Arbor, MI 48105, USA
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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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