Efficient suppression of premature termination codons with alanine by engineered chimeric pyrrolysine tRNAs [Ribo-Seq]
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PROVIDER: PRJNA1160843 | ENA |
REPOSITORIES: ENA
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Project description:Efficient suppression of premature termination codons with alanine by engineered chimeric pyrrolysine tRNAs
| PRJNA1160838 | ENA
Project description:Mutations that introduce premature termination codons (PTCs) within protein-coding genes are associated with incurable and severe genetic diseases. Many PTC-associated disorders are life-threatening and have no approved medical treatment options. Suppressor transfer RNAs (sup-tRNAs) with the capacity to promote translational readthrough of PTCs represent a promising therapeutic strategy to treat these conditions; however, developing novel sup-tRNAs with high efficiency and specificity often requires extensive engineering and screening. Moreover, these efforts are not always successful at producing more efficient sup-tRNAs. Here we show that a pyrrolysine tRNA (tRNAPyl), which naturally translates the UAG stop codon, offers an attractive scaffold for developing effective sup-tRNAs that restore protein synthesis from PTC-containing genes. We created a series of rationally designed Pyrrolysine tRNA Scaffold Suppressor-tRNAs (PASS-tRNAs) that are substrates of bacterial and human alanyl-tRNA synthetase. Using a PTC-containing fluorescent reporter gene, PASS-tRNAs restore protein synthesis to wild-type levels in bacterial cells. In human cells, PASS-tRNAs display robust and consistent PTC suppression in multiple reporter genes, including pathogenic mutations in the tumor suppressor gene BRCA1 associated with breast and ovarian cancer. Moreover, PTC suppression occurred with high codon specificity and no observed cytotoxic effects. Collectively, these results unveil a class of sup-tRNAs with great potential for tRNA-based therapeutics.
2024-12-27 | GSE277130 | GEO
Project description:Mutations that introduce premature termination codons (PTCs) within protein-coding genes are associated with incurable and severe genetic diseases. Many PTC-associated disorders are life-threatening and have no approved medical treatment options. Suppressor transfer RNAs (sup-tRNAs) with the capacity to promote translational readthrough of PTCs represent a promising therapeutic strategy to treat these conditions; however, developing novel sup-tRNAs with high efficiency and specificity often requires extensive engineering and screening. Moreover, these efforts are not always successful at producing more efficient sup-tRNAs. Here we show that a pyrrolysine tRNA (tRNAPyl), which naturally translates the UAG stop codon, offers an attractive scaffold for developing effective sup-tRNAs that restore protein synthesis from PTC-containing genes. We created a series of rationally designed Pyrrolysine tRNA Scaffold Suppressor-tRNAs (PASS-tRNAs) that are substrates of bacterial and human alanyl-tRNA synthetase. Using a PTC-containing fluorescent reporter gene, PASS-tRNAs restore protein synthesis to wild-type levels in bacterial cells. In human cells, PASS-tRNAs display robust and consistent PTC suppression in multiple reporter genes, including pathogenic mutations in the tumor suppressor gene BRCA1 associated with breast and ovarian cancer. Moreover, PTC suppression occurred with high codon specificity and no observed cytotoxic effects. Collectively, these results unveil a class of sup-tRNAs with great potential for tRNA-based therapeutics.
2024-12-27 | GSE277128 | GEO
Project description:By physically linking amino acids to their codon assignments, transfer RNAs (tRNAs) are essential for protein synthesis and translation fidelity. Some natural human tRNA variants cause amino acid mis-incorporation at a codon or set of codons. Recent work showed a naturally occurring tRNASer variant decodes phenylalanine codons with serine and inhibits protein synthesis. We hypothesized that human tRNA variants that mis-read glycine (Gly) codons with alanine (Ala) will 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 several 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.
2024-05-21 | PXD034180 | Pride
Project description:Mistranslation, the mis-incorporation of an amino acid not specified by the “standard” genetic code, occurs in all cells. tRNA variants that increase mistranslation arise spontaneously and engineered tRNAs can achieve mistranslation frequencies approaching 10% in yeast and bacteria. The goal of this study was to assess the transcriptome changes in yeast cells expressing two different mistranslating tRNA variants which mistranslate at similar frequencies (of ~ 3%) but result in different substitutions, namely alanine at proline codons or serine at arginine codons.
2021-05-11 | GSE174145 | GEO
Project description:Nonsense mutations, responsible for ~11% of genetic diseases, create premature stop codons (PTCs) and lead to truncated and often non-functional proteins. Recently, programmable RNA pseudouridylation has emerged as a new type of RNA base editor to suppress PTCs. However, current methods suffer from low efficiency and limited precision. Here, we develop RESTART v3, an updated version of RESTART, which utilizes near-cognate tRNAs to improve the readthrough efficiency of pseudouridine-modified PTCs. We show an average of ~5-fold higher editing efficiency than RESTART v2 in cultured cells, currently the most active RNA pseudouridylation tool to mediate PTC readthrough. Moreover, RESTART v3 achieves functional PTC readthrough in disease cell models of cystic fibrosis and Hurler syndrome. Furthermore, RESTART v3 enables accurate incorporation of the original amino acid for nearly half of the PTC sites, considering the naturally occurring frequencies of sense to nonsense codons. In line with the benign off-target effect of RESTART, RESTART v3 does not change the coding information nor the expression level of transcripts with off-target editing; except for the specifically overexpressed tRNA molecule, it does not alter the expression level of endogenous tRNA pool. Overall, RESTART v3 represents an enhanced RNA base editor with increased efficiency and accuracy.
2024-01-29 | GSE237632 | GEO
Project description:Nonsense mutations, responsible for ~11% of genetic diseases, create premature stop codons (PTCs) and lead to truncated and often non-functional proteins. Recently, programmable RNA pseudouridylation has emerged as a new type of RNA base editor to suppress PTCs. However, current methods suffer from low efficiency and limited precision. Here, we develop RESTART v3, an updated version of RESTART, which utilizes near-cognate tRNAs to improve the readthrough efficiency of pseudouridine-modified PTCs. We show an average of ~5-fold higher editing efficiency than RESTART v2 in cultured cells, currently the most active RNA pseudouridylation tool to mediate PTC readthrough. Moreover, RESTART v3 achieves functional PTC readthrough in disease cell models of cystic fibrosis and Hurler syndrome. Furthermore, RESTART v3 enables accurate incorporation of the original amino acid for nearly half of the PTC sites, considering the naturally occurring frequencies of sense to nonsense codons. In line with the benign off-target effect of RESTART, RESTART v3 does not change the coding information nor the expression level of transcripts with off-target editing; except for the specifically overexpressed tRNA molecule, it does not alter the expression level of endogenous tRNA pool. Overall, RESTART v3 represents an enhanced RNA base editor with increased efficiency and accuracy.
2024-01-29 | GSE237630 | GEO
Project description:Nonsense mutations, responsible for ~11% of genetic diseases, create premature stop codons (PTCs) and lead to truncated and often non-functional proteins. Recently, programmable RNA pseudouridylation has emerged as a new type of RNA base editor to suppress PTCs. However, current methods suffer from low efficiency and limited precision. Here, we develop RESTART v3, an updated version of RESTART, which utilizes near-cognate tRNAs to improve the readthrough efficiency of pseudouridine-modified PTCs. We show an average of ~5-fold higher editing efficiency than RESTART v2 in cultured cells, currently the most active RNA pseudouridylation tool to mediate PTC readthrough. Moreover, RESTART v3 achieves functional PTC readthrough in disease cell models of cystic fibrosis and Hurler syndrome. Furthermore, RESTART v3 enables accurate incorporation of the original amino acid for nearly half of the PTC sites, considering the naturally occurring frequencies of sense to nonsense codons. In line with the benign off-target effect of RESTART, RESTART v3 does not change the coding information nor the expression level of transcripts with off-target editing; except for the specifically overexpressed tRNA molecule, it does not alter the expression level of endogenous tRNA pool. Overall, RESTART v3 represents an enhanced RNA base editor with increased efficiency and accuracy.
2024-01-29 | GSE237631 | GEO
Project description:Nonsense mutations, responsible for ~11% of genetic diseases, create premature stop codons (PTCs) and lead to truncated and often non-functional proteins. Recently, programmable RNA pseudouridylation has emerged as a new type of RNA base editor to suppress PTCs. However, current methods suffer from low efficiency and limited precision. Here, we develop RESTART v3, an updated version of RESTART, which utilizes near-cognate tRNAs to improve the readthrough efficiency of pseudouridine-modified PTCs. We show an average of ~5-fold higher editing efficiency than RESTART v2 in cultured cells, currently the most active RNA pseudouridylation tool to mediate PTC readthrough. Moreover, RESTART v3 achieves functional PTC readthrough in disease cell models of cystic fibrosis and Hurler syndrome. Furthermore, RESTART v3 enables accurate incorporation of the original amino acid for nearly half of the PTC sites, considering the naturally occurring frequencies of sense to nonsense codons. In line with the benign off-target effect of RESTART, RESTART v3 does not change the coding information nor the expression level of transcripts with off-target editing; except for the specifically overexpressed tRNA molecule, it does not alter the expression level of endogenous tRNA pool. Overall, RESTART v3 represents an enhanced RNA base editor with increased efficiency and accuracy.
2024-01-29 | GSE237629 | GEO
Project description:Near-cognate tRNAs increase the efficiency and precision of pseudouridine-mediated readthrough of premature termination codons
| PRJNA996057 | ENA