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Isaacson JR, Berg MD, Yeung W, Villén J, Brandl CJ, Moehring AJ. Impact of tRNA-induced proline-to-serine mistranslation on the transcriptome of Drosophila melanogaster. G3 (BETHESDA, MD.) 2024; 14:jkae151. [PMID: 38989890 PMCID: PMC11373654 DOI: 10.1093/g3journal/jkae151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Revised: 06/16/2024] [Accepted: 07/03/2024] [Indexed: 07/12/2024]
Abstract
Mistranslation is the misincorporation of an amino acid into a polypeptide. Mistranslation has diverse effects on multicellular eukaryotes and is implicated in several human diseases. In Drosophila melanogaster, a serine transfer RNA (tRNA) that misincorporates serine at proline codons (P→S) affects male and female flies differently. The mechanisms behind this discrepancy are currently unknown. Here, we compare the transcriptional response of male and female flies to P→S mistranslation to identify genes and cellular processes that underlie sex-specific differences. Both males and females downregulate genes associated with various metabolic processes in response to P→S mistranslation. Males downregulate genes associated with extracellular matrix organization and response to negative stimuli such as wounding, whereas females downregulate aerobic respiration and ATP synthesis genes. Both sexes upregulate genes associated with gametogenesis, but females also upregulate cell cycle and DNA repair genes. These observed differences in the transcriptional response of male and female flies to P→S mistranslation have important implications for the sex-specific impact of mistranslation on disease and tRNA therapeutics.
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Affiliation(s)
| | - Matthew D Berg
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - William Yeung
- Department of Biology, Western University, London, Canada, N6A 5B7
| | - Judit Villén
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
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Isaacson JR, Berg MD, Jagiello J, Yeung W, Charles B, Villén J, Brandl CJ, Moehring AJ. Mistranslating tRNA variants have anticodon- and sex-specific impacts on Drosophila melanogaster. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.11.598535. [PMID: 38915589 PMCID: PMC11195196 DOI: 10.1101/2024.06.11.598535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Transfer RNAs (tRNAs) are vital in determining the specificity of translation. Mutations in tRNA genes can result in the misincorporation of amino acids into nascent polypeptides in a process known as mistranslation. Since mistranslation has different impacts, depending on the type of amino acid substitution, our goal here was to compare the impact of different mistranslating tRNASer variants on fly development, lifespan, and behaviour. We established two mistranslating fly lines, one with a tRNASer variant that misincorporates serine at valine codons (V→S) and the other that misincorporates serine at threonine codons (T→S). While both mistranslating tRNAs increased development time and developmental lethality, the severity of the impacts differed depending on amino acid substitution and sex. The V→S variant extended embryonic, larval, and pupal development whereas the T→S only extended larval and pupal development. Females, but not males, containing either mistranslating tRNA presented with significantly more anatomical deformities than controls. Mistranslating females also experienced extended lifespan whereas mistranslating male lifespan was unaffected. In addition, mistranslating flies from both sexes showed improved locomotion as they aged, suggesting delayed neurodegeneration. Therefore, although mistranslation causes detrimental effects, we demonstrate that mistranslation also has positive effects on complex traits such as lifespan and locomotion. This has important implications for human health given the prevalence of tRNA variants in humans.
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Affiliation(s)
| | - Matthew D. Berg
- Department of Genome Sciences, University of Washington, Seattle, Washington, 98195
| | - Jessica Jagiello
- Department of Biology, Western University, N6A 5B7, London, Canada
| | - William Yeung
- Department of Biology, Western University, N6A 5B7, London, Canada
| | - Brendan Charles
- Department of Biology, Western University, N6A 5B7, London, Canada
| | - Judit Villén
- Department of Genome Sciences, University of Washington, Seattle, Washington, 98195
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3
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Isaacson JR, Berg MD, Yeung W, Villén J, Brandl CJ, Moehring AJ. Impact of tRNA-induced proline-to-serine mistranslation on the transcriptome of Drosophila melanogaster. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.08.593249. [PMID: 38766246 PMCID: PMC11100759 DOI: 10.1101/2024.05.08.593249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Mistranslation is the misincorporation of an amino acid into a polypeptide. Mistranslation has diverse effects on multicellular eukaryotes and is implicated in several human diseases. In Drosophila melanogaster, a serine transfer RNA (tRNA) that misincorporates serine at proline codons (P→S) affects male and female flies differently. The mechanisms behind this discrepancy are currently unknown. Here, we compare the transcriptional response of male and female flies to P→S mistranslation to identify genes and cellular processes that underlie sex-specific differences. Both males and females downregulate genes associated with various metabolic processes in response to P→S mistranslation. Males downregulate genes associated with extracellular matrix organization and response to negative stimuli such as wounding, whereas females downregulate aerobic respiration and ATP synthesis genes. Both sexes upregulate genes associated with gametogenesis, but females also upregulate cell cycle and DNA repair genes. These observed differences in the transcriptional response of male and female flies to P→S mistranslation have important implications for the sex-specific impact of mistranslation on disease and tRNA therapeutics.
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Affiliation(s)
| | - Matthew D. Berg
- Department of Genome Sciences, University of Washington, Seattle, Washington, 98195
| | - William Yeung
- Department of Biology, Western University, N6A 5B7, London, Canada
| | - Judit Villén
- Department of Genome Sciences, University of Washington, Seattle, Washington, 98195
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Davey-Young J, Hasan F, Tennakoon R, Rozik P, Moore H, Hall P, Cozma E, Genereaux J, Hoffman KS, Chan PP, Lowe TM, Brandl CJ, O’Donoghue P. Mistranslating the genetic code with leucine in yeast and mammalian cells. RNA Biol 2024; 21:1-23. [PMID: 38629491 PMCID: PMC11028032 DOI: 10.1080/15476286.2024.2340297] [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] [Accepted: 04/03/2024] [Indexed: 04/19/2024] Open
Abstract
Translation fidelity relies on accurate aminoacylation of transfer RNAs (tRNAs) by aminoacyl-tRNA synthetases (AARSs). AARSs specific for alanine (Ala), leucine (Leu), serine, and pyrrolysine do not recognize the anticodon bases. Single nucleotide anticodon variants in their cognate tRNAs can lead to mistranslation. Human genomes include both rare and more common mistranslating tRNA variants. We investigated three rare human tRNALeu variants that mis-incorporate Leu at phenylalanine or tryptophan codons. Expression of each tRNALeu anticodon variant in neuroblastoma cells caused defects in fluorescent protein production without significantly increased cytotoxicity under normal conditions or in the context of proteasome inhibition. Using tRNA sequencing and mass spectrometry we confirmed that each tRNALeu variant was expressed and generated mistranslation with Leu. To probe the flexibility of the entire genetic code towards Leu mis-incorporation, we created 64 yeast strains to express all possible tRNALeu anticodon variants in a doxycycline-inducible system. While some variants showed mild or no growth defects, many anticodon variants, enriched with G/C at positions 35 and 36, including those replacing Leu for proline, arginine, alanine, or glycine, caused dramatic reductions in growth. Differential phenotypic defects were observed for tRNALeu mutants with synonymous anticodons and for different tRNALeu isoacceptors with the same anticodon. A comparison to tRNAAla anticodon variants demonstrates that Ala mis-incorporation is more tolerable than Leu at nearly every codon. The data show that the nature of the amino acid substitution, the tRNA gene, and the anticodon are each important factors that influence the ability of cells to tolerate mistranslating tRNAs.
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Affiliation(s)
- Josephine Davey-Young
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Farah Hasan
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Rasangi Tennakoon
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Peter Rozik
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Henry Moore
- Department of Biomolecular Engineering, Baskin School of Engineering & UCSC Genomics Institute, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Peter Hall
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Ecaterina Cozma
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Julie Genereaux
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | | | - Patricia P. Chan
- Department of Biomolecular Engineering, Baskin School of Engineering & UCSC Genomics Institute, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Todd M. Lowe
- Department of Biomolecular Engineering, Baskin School of Engineering & UCSC Genomics Institute, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Christopher J. Brandl
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Patrick O’Donoghue
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
- Department of Chemistry, The University of Western Ontario, London, Ontario, Canada
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5
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Hasan F, Lant JT, O'Donoghue P. Perseverance of protein homeostasis despite mistranslation of glycine codons with alanine. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220029. [PMID: 36633285 PMCID: PMC9835607 DOI: 10.1098/rstb.2022.0029] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 10/05/2022] [Indexed: 01/13/2023] Open
Abstract
By linking amino acids to their codon assignments, transfer RNAs (tRNAs) are essential for protein synthesis and translation fidelity. Some human tRNA variants cause amino acid mis-incorporation at a codon or set of codons. We recently found that a naturally occurring tRNASer variant decodes phenylalanine codons with serine and inhibits protein synthesis. Here, we hypothesized that human tRNA variants that misread glycine (Gly) codons with alanine (Ala) will also disrupt protein homeostasis. The A3G mutation occurs naturally in tRNAGly variants (tRNAGlyCCC, tRNAGlyGCC) and creates an alanyl-tRNA synthetase (AlaRS) identity element (G3 : U70). Because AlaRS does not recognize the anticodon, the human tRNAAlaAGC G35C (tRNAAlaACC) variant may function similarly to mis-incorporate Ala at Gly codons. The tRNAGly and tRNAAla variants had no effect on protein synthesis in mammalian cells under normal growth conditions; however, tRNAGlyGCC A3G depressed protein synthesis in the context of proteasome inhibition. Mass spectrometry confirmed Ala mistranslation at multiple Gly codons caused by the tRNAGlyGCC A3G and tRNAAlaAGC G35C mutants, and in some cases, we observed multiple mistranslation events in the same peptide. The data reveal mistranslation of Ala at Gly codons and defects in protein homeostasis generated by natural human tRNA variants that are tolerated under normal conditions. This article is part of the theme issue 'Reactivity and mechanism in chemical and synthetic biology'.
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MESH Headings
- Humans
- Alanine/genetics
- Alanine/chemistry
- Alanine/metabolism
- Alanine-tRNA Ligase/chemistry
- Alanine-tRNA Ligase/genetics
- Alanine-tRNA Ligase/metabolism
- Codon/genetics
- Glycine/genetics
- Glycine/metabolism
- Protein Biosynthesis
- Proteostasis
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- RNA, Transfer, Ala/chemistry
- RNA, Transfer, Ala/genetics
- RNA, Transfer, Ala/metabolism
- RNA, Transfer, Gly/metabolism
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Affiliation(s)
- Farah Hasan
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada N6A 5C1
| | - Jeremy T. Lant
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada N6A 5C1
| | - Patrick O'Donoghue
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada N6A 5C1
- Department of Chemistry, The University of Western Ontario, London, Ontario, Canada N6A 5C1
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Cozma E, Rao M, Dusick M, Genereaux J, Rodriguez-Mias RA, Villén J, Brandl CJ, Berg MD. Anticodon sequence determines the impact of mistranslating tRNA Ala variants. RNA Biol 2023; 20:791-804. [PMID: 37776539 PMCID: PMC10543346 DOI: 10.1080/15476286.2023.2257471] [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] [Accepted: 08/31/2023] [Indexed: 10/02/2023] Open
Abstract
Transfer RNAs (tRNAs) maintain translation fidelity through accurate charging by their cognate aminoacyl-tRNA synthetase and codon:anticodon base pairing with the mRNA at the ribosome. Mistranslation occurs when an amino acid not specified by the genetic message is incorporated into proteins and has applications in biotechnology, therapeutics and is relevant to disease. Since the alanyl-tRNA synthetase uniquely recognizes a G3:U70 base pair in tRNAAla and the anticodon plays no role in charging, tRNAAla variants with anticodon mutations have the potential to mis-incorporate alanine. Here, we characterize the impact of the 60 non-alanine tRNAAla anticodon variants on the growth of Saccharomyces cerevisiae. Overall, 36 tRNAAla anticodon variants decreased growth in single- or multi-copy. Mass spectrometry analysis of the cellular proteome revealed that 52 of 57 anticodon variants, not decoding alanine or stop codons, induced mistranslation when on single-copy plasmids. Variants with G/C-rich anticodons resulted in larger growth deficits than A/U-rich variants. In most instances, synonymous anticodon variants impact growth differently, with anticodons containing U at base 34 being the least impactful. For anticodons generating the same amino acid substitution, reduced growth generally correlated with the abundance of detected mistranslation events. Differences in decoding specificity, even between synonymous anticodons, resulted in each tRNAAla variant mistranslating unique sets of peptides and proteins. We suggest that these differences in decoding specificity are also important in determining the impact of tRNAAla anticodon variants.
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Affiliation(s)
- Ecaterina Cozma
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Megha Rao
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Madison Dusick
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Julie Genereaux
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | | | - Judit Villén
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Christopher J. Brandl
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Matthew D. Berg
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
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Berg MD, Zhu Y, Loll-Krippleber R, San Luis BJ, Genereaux J, Boone C, Villén J, Brown GW, Brandl CJ. Genetic background and mistranslation frequency determine the impact of mistranslating tRNASerUGG. G3 GENES|GENOMES|GENETICS 2022; 12:6588684. [PMID: 35587152 PMCID: PMC9258585 DOI: 10.1093/g3journal/jkac125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 05/07/2022] [Indexed: 12/02/2022]
Abstract
Transfer RNA variants increase the frequency of mistranslation, the misincorporation of an amino acid not specified by the “standard” genetic code, to frequencies approaching 10% in yeast and bacteria. Cells cope with these variants by having multiple copies of each tRNA isodecoder and through pathways that deal with proteotoxic stress. In this study, we define the genetic interactions of the gene encoding tRNASerUGG,G26A, which mistranslates serine at proline codons. Using a collection of yeast temperature-sensitive alleles, we identify negative synthetic genetic interactions between the mistranslating tRNA and 109 alleles representing 91 genes, with nearly half of the genes having roles in RNA processing or protein folding and turnover. By regulating tRNA expression, we then compare the strength of the negative genetic interaction for a subset of identified alleles under differing amounts of mistranslation. The frequency of mistranslation correlated with the impact on cell growth for all strains analyzed; however, there were notable differences in the extent of the synthetic interaction at different frequencies of mistranslation depending on the genetic background. For many of the strains, the extent of the negative interaction with tRNASerUGG,G26A was proportional to the frequency of mistranslation or only observed at intermediate or high frequencies. For others, the synthetic interaction was approximately equivalent at all frequencies of mistranslation. As humans contain similar mistranslating tRNAs, these results are important when analyzing the impact of tRNA variants on disease, where both the individual’s genetic background and the expression of the mistranslating tRNA variant need to be considered.
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Affiliation(s)
- Matthew D Berg
- Department of Biochemistry, The University of Western Ontario , London, ON N6A 5C1, Canada
- Department of Genome Sciences, University of Washington , Seattle, WA 98195, USA
| | - Yanrui Zhu
- Department of Biochemistry, The University of Western Ontario , London, ON N6A 5C1, Canada
| | - Raphaël Loll-Krippleber
- Department of Biochemistry, Donnelly Centre for Cellular and Biomolecular Research, University of Toronto , Toronto, ON M5S 3E1, Canada
| | - Bryan-Joseph San Luis
- Department of Molecular Genetics, Donnelly Centre for Cellular and Biomolecular Research, University of Toronto , Toronto, ON M5S 1A8, Canada
| | - Julie Genereaux
- Department of Biochemistry, The University of Western Ontario , London, ON N6A 5C1, Canada
| | - Charles Boone
- Department of Molecular Genetics, Donnelly Centre for Cellular and Biomolecular Research, University of Toronto , Toronto, ON M5S 1A8, Canada
| | - Judit Villén
- Department of Genome Sciences, University of Washington , Seattle, WA 98195, USA
| | - Grant W Brown
- Department of Biochemistry, Donnelly Centre for Cellular and Biomolecular Research, University of Toronto , Toronto, ON M5S 3E1, Canada
| | - Christopher J Brandl
- Department of Biochemistry, The University of Western Ontario , London, ON N6A 5C1, Canada
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