Potassium tellurite exerts its toxicity on ribosome in Escherichia coli
Ontology highlight
ABSTRACT:
ORGANISM(S): Escherichia coli
PROVIDER: GSE109907 | GEO | 2021/01/29
REPOSITORIES: GEO
Similar Datasets
Project description:Stop codon readthrough (SCR) occurs when the ribosome miscodes at a stop codon. Such readthrough events can be therapeutically desirable when a premature termination codon (PTC) is found in a critical gene. To study SCR in vivo in a genome-wide manner, we treated mammalian cells with aminoglycosides and performed ribosome profiling. We find that in addition to stimulating readthrough of PTCs, aminoglycosides stimulate readthrough of normal termination codons (NTCs) genome-wide. Stop codon identity, the nucleotide following the stop codon, and the surrounding mRNA sequence context all influence the likelihood of SCR. In comparison to NTCs, downstream stop codons in 3′UTRs are recognized less efficiently by ribosomes, suggesting that targeting of critical stop codons for readthrough may be achievable without general disruption of translation termination. Finally, we find that G418 treatment globally alters gene expression with substantial effects on translation of histone genes, selenoprotein genes, and S-adenosylmethionine decarboxylase (AMD1).
2020-01-14 | GSE138641 | GEO
Project description:Stop codon readthrough (SCR) occurs when the ribosome miscodes at a stop codon. Such readthrough events can be therapeutically desirable when a premature termination codon (PTC) is found in a critical gene. To study SCR in vivo in a genome-wide manner, we treated mammalian cells with aminoglycosides and performed ribosome profiling. We find that in addition to stimulating readthrough of PTCs, aminoglycosides stimulate readthrough of normal termination codons (NTCs) genome-wide. Stop codon identity, the nucleotide following the stop codon, and the surrounding mRNA sequence context all influence the likelihood of SCR. In comparison to NTCs, downstream stop codons in 3′UTRs are recognized less efficiently by ribosomes, suggesting that targeting of critical stop codons for readthrough may be achievable without general disruption of translation termination. Finally, we find that G418 treatment globally alters gene expression with substantial effects on translation of histone genes, selenoprotein genes, and S-adenosylmethionine decarboxylase (AMD1).
2020-01-14 | GSE138640 | GEO
Project description:Stop codon readthrough (SCR) occurs when the ribosome miscodes at a stop codon. Such readthrough events can be therapeutically desirable when a premature termination codon (PTC) is found in a critical gene. To study SCR in vivo in a genome-wide manner, we treated mammalian cells with aminoglycosides and performed ribosome profiling. We find that in addition to stimulating readthrough of PTCs, aminoglycosides stimulate readthrough of normal termination codons (NTCs) genome-wide. Stop codon identity, the nucleotide following the stop codon, and the surrounding mRNA sequence context all influence the likelihood of SCR. In comparison to NTCs, downstream stop codons in 3′UTRs are recognized less efficiently by ribosomes, suggesting that targeting of critical stop codons for readthrough may be achievable without general disruption of translation termination. Finally, we find that G418 treatment globally alters gene expression with substantial effects on translation of histone genes, selenoprotein genes, and S-adenosylmethionine decarboxylase (AMD1).
2020-01-14 | GSE138639 | GEO
Project description:Stop codon readthrough (SCR) occurs when the ribosome miscodes at a stop codon. Such readthrough events can be therapeutically desirable when a premature termination codon (PTC) is found in a critical gene. To study SCR in vivo in a genome-wide manner, we treated mammalian cells with aminoglycosides and performed ribosome profiling. We find that in addition to stimulating readthrough of PTCs, aminoglycosides stimulate readthrough of normal termination codons (NTCs) genome-wide. Stop codon identity, the nucleotide following the stop codon, and the surrounding mRNA sequence context all influence the likelihood of SCR. In comparison to NTCs, downstream stop codons in 3′UTRs are recognized less efficiently by ribosomes, suggesting that targeting of critical stop codons for readthrough may be achievable without general disruption of translation termination. Finally, we find that G418 treatment globally alters gene expression with substantial effects on translation of histone genes, selenoprotein genes, and S-adenosylmethionine decarboxylase (AMD1).
2020-01-14 | GSE138638 | GEO
Project description:Stop codon readthrough (SCR) occurs when the ribosome miscodes at a stop codon. Such readthrough events can be therapeutically desirable when a premature termination codon (PTC) is found in a critical gene. To study SCR in vivo in a genome-wide manner, we treated mammalian cells with aminoglycosides and performed ribosome profiling. We find that in addition to stimulating readthrough of PTCs, aminoglycosides stimulate readthrough of normal termination codons (NTCs) genome-wide. Stop codon identity, the nucleotide following the stop codon, and the surrounding mRNA sequence context all influence the likelihood of SCR. In comparison to NTCs, downstream stop codons in 3′UTRs are recognized less efficiently by ribosomes, suggesting that targeting of critical stop codons for readthrough may be achievable without general disruption of translation termination. Finally, we find that G418 treatment globally alters gene expression with substantial effects on translation of histone genes, selenoprotein genes, and S-adenosylmethionine decarboxylase (AMD1).
2020-01-14 | GSE138642 | GEO
Project description:Terminating protein translation accurately and efficiently is critical for both protein fidelity and ribosome recycling for continued translation. The three bacterial release factors (RFs) play key roles: RF1 and 2 recognize stop codons and terminate translation; and RF3 promotes disassociation of bound release factors. Probing release factors mutations with reporter constructs containing programmed frameshifting sequences or premature stop codons had revealed a propensity for readthrough or frameshifting at these specific sites, but their effects on translation genome-wide have not been examined. We performed ribosome profiling on a set of isogenic strains with well-characterized release factor mutations to determine how they alter translation globally. Consistent with their known defects, strains with increasingly severe release factor defects exhibit increasingly severe accumulation of ribosomes over stop codons, indicative of an increased duration of the termination/release phase of translation. Release factor mutant strains also exhibit increased occupancy in the region following the stop codon at a significant number of genes. Our global analysis revealed that, as expected, translation termination is generally efficient and accurate, but that at a significant number of genes (≥ 50) the ribosome signature after the stop codon is suggestive of translation past the stop codon. Even native E. coli K-12 exhibits the ribosome signature suggestive of protein extension, especially at UGA codons, which rely exclusively on the reduced function RF2 allele of the K-12 strain for termination. Deletion of RF3 increases the severity of the defect. We unambiguously demonstrate readthrough and frameshifting protein extensions and their further accumulation in mutant strains for a few select cases. In addition to enhancing recoding, ribosome accumulation over stop codons disrupts attenuation control of biosynthetic operons, and may alter expression of some overlapping genes. Together, these functional alterations may either augment the protein repertoire or produce deleterious proteins.
2017-03-09 | GSE88725 | GEO
Project description:Translation of mRNA into a polypeptide is terminated when the release factor eRF1 recognizes a UAA, UAG, or UGA stop codon in the ribosomal A site and stimulates nascent peptide release. However, stop codon readthrough can occur when a near-cognate tRNA outcompetes eRF1 in decoding the stop codon, resulting in the continuation of the elongation phase of protein synthesis. At the end of a conventional mRNA coding region readthrough allows translation into the mRNA 3’-UTR. Previous studies with reporter systems have shown that the efficiency of termination or readthrough is modulated by cis-acting elements other than stop codon identity, including two nucleotides 5’ of the stop codon, six nucleotides 3’ of the stop codon in the ribosomal mRNA channel, and stem-loop structures in the mRNA 3’-UTR. It is unknown whether these elements are important at a genome-wide level and whether other mRNA features proximal to the stop codon significantly affect termination and readthrough efficiencies in vivo. Accordingly, we carried out ribosome profiling analyses of yeast cells expressing wild-type or temperature-sensitive eRF1 and developed bioinformatics strategies to calculate readthrough efficiency, and to identify mRNA and peptide features which influence that efficiency. We found that the stop codon (nt +1 to +3), the nucleotide after it (nt +4), the codon in the P site (nt -3 to -1), and 3’-UTR length are the most influential features in the control of readthrough efficiency, while nts +5 to +9 and mRNA secondary structure in the 3’-UTR had milder effects. Additionally, we found low readthrough genes to have shorter 3’-UTRs compared to high readthrough genes in cells with thermally inactivated eRF1, while this trend was reversed in wild-type cells. Together, our results demonstrated the general roles of known regulatory elements in genome-wide regulation and identified several new mRNA or peptide features important for translation termination and readthrough.
2020-12-08 | GSE162780 | GEO
Project description:Proline-rich antimicrobial peptide apidaecin (Api) inhibits bacterial protein synthesis in a distinctive way. In vitro biochemical and structural studies showed that Api binds in the nascent peptide exit tunnel of the ribosome that has completed translation of the gene and has released the newly-synthesized protein. Once in the tunnel, Api traps the release factors on the post-termination ribosome leading to cessation of translation. The mode of Api action in the bacterial cell, however, had remained unknow. By analyzing distribution of ribosomes on mRNAs in Api-treated cells using Ribo-seq approach we uncovered a range of effects that stem from the unique mechanism of Api action. Exposure of bacterial cells to Api results in arrest of translation at stop codons, likely in a post-release state, due to the immediate Api action, as well as in a pre-release state due to the depletion of available release factors. In addition, arrest of translation at the end of the open reading frame (ORF) leads to a pronounced queuing of the translating ribosomes behind the one arrested at the stop codon. One of the major consequences of the Api action is a dramatically increased stop codon bypass by the ribosomes paused in a pre-release state, leading to accumulation of proteins with C-terminal extensions, as confirmed by whole-cell proteomics analysis. Stop codon bypass, that occurs either in 0-frame, by misincorporation of a near-cognate aminoacyl-tRNA at the stop codon, or via frameshifting allows for a fraction of the translating ribosomes to reach the 3’ ends of mRNA transcripts. The pervasive stalling of pre-release ribosomes at the stop codons and at the RNA transcripts ends triggers activation of the cellular ribosome rescue systems which, likely due to Api action as well, remain ineffective. While major Api effects are directed towards the ribosome at the end of the ORFs, cells exposed to Api show a somewhat increased ribosome occupancy of the start codons. Understanding the unique mode of Api to inhibit translation termination in the cell can help envisioning the development of treatments for genetic diseases and research tools for genome exploration.
2020-10-05 | PXD019012 | Pride
Project description:The ribosome-associated quality control (RQC) is a surveillance system for aberrant translation, sensing ribosome collisions. Although the molecular mechanism has been extensively studied, the endogenous targets of RQC in human cells were poorly understood. Here, starting from the study of codon specificity of eukaryotic termination factor eRF1, we unexpectedly find that misrecognition of UUA sense codon by eRF1 leads to ribosome collisions and provides the source of RQC substrates in humans. eRF1-selective Monosome-Seq and Disome-Seq reveal that eRF1 recruitment to ribosome was not restricted to the stop codons but also the sub-cognate sense codons, including the UUA codon. The UUA misrecognition by eRF1 causes ribosome collision without termination reaction. Remarkably, Disome-Seq with the depletion of ASCC3 and 4EHP, key factors in RQC, showed that ribosome stalled at UUA codons are the predominant sub-populations rescued by RQC. Failure to resolve ribosome collisions by RQC triggers p38 phosphorylation and upregulation of stress response transcription factor ATF3. This study presents the impact of sense codon misrecognition by the termination factor on translation homeostasis in human cells.
2024-09-18 | GSE275336 | GEO
Project description:The proline-rich antimicrobial peptide apidaecin (Api) inhibits bacterial protein synthesis in a distinctive way. In vitro biochemical and structural studies showed that Api binds in the nascent peptide exit tunnel of a ribosome that has completed translation of a gene and traps the release factors on the ribosome. By analyzing the distribution of ribosomes on mRNAs in Api-treated cells using Ribo-seq, we uncovered a range of effects that stem from the unique mechanism of Api action. Exposure of bacterial cells to Api results in arrest of ribosomes at stop codons, likely in a post-release state due to direct Api action, as well as in a pre-release state due to the depletion of available release factors. In addition, Api action leads to a pronounced queuing of translating ribosomes behind those arrested at stop codons. One of the major consequences of Api action is a dramatically increased level of stop codon bypass by ribosomes paused in a pre-release state, leading to an accumulation of proteins with C-terminal extensions, as confirmed by whole-cell proteomics analysis. Stop codon bypass occurs either in 0-frame, by misincorporation of a near-cognate aminoacyl-tRNA at the stop codon, or via frameshifting, allowing for a fraction of the translating ribosomes to reach the 3’ ends of mRNA transcripts. The pervasive stalling of pre-release ribosomes at the stop codons and at the RNA transcripts ends triggers activation of the cellular ribosome rescue systems which, likely due to Api action as well, remain ineffective. Understanding the unique mode of Api action as translation termination inhibitor in the cell can advance the development of treatments for infection and genetic diseases as well as new research tools for genome exploration.
2020-10-02 | GSE150034 | GEO