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PROVIDER: PRJNA380970 | ENA |
REPOSITORIES: ENA
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Project description:Eukaryotic cells rapidly reduce protein synthesis in response to various stress conditions. This can be achieved by the phosphorylation-mediated inactivation of a key translation initiation factor, eIF2. However, the persistent translation of certain mRNAs is required for deployment of an adequate stress response. We carried out ribosome profiling of cultured human cells under conditions of severe stress induced with sodium arsenite. Although this led to a ~4.5-fold general translational repression, the protein coding ORFs of certain individual mRNAs exhibited resistance to the inhibition. Nearly all resistant transcripts possess at least one efficiently translated uORF that repress translation of the main coding ORF under normal conditions. Site specific mutagenesis of two identified stress resistant mRNAs (PPP1R15B and IFRD1) demonstrated that a single uORF is sufficient for eIF2-mediated translation control in both cases. Phylogenetic analysis suggests that at least two regulatory uORFs (namely in SLC35A4 and MIEF1) encode functional protein products. Ribosome profiling of sodium arsenite treated cells for examination of translational response to induction of eIF2 phosphoylation
2015-01-27 | E-GEOD-55195 | biostudies-arrayexpress
Project description:The eIF2 initiation complex is central to maintaining a functional translation machinery. Extreme stress such as life-threatening sepsis exposes vulnerabilities in this tightly regulated system, resulting in an imbalance between the opposing actions of kinases and phosphatases on the main regulatory subunit eIF2α. Here, we report that translation shutdown is a hallmark of established sepsis-induced kidney injury brought about by excessive eIF2α phosphorylation and sustained by blunted expression of the counterregulatory phosphatase subunit Ppp1r15a. We determined that the blunted Ppp1r15a expression persists because of the presence of an upstream open reading frame (uORF). Overcoming this barrier with genetic approaches enabled the derepression of Ppp1r15a, salvaged translation and improved kidney function in an endotoxemia model. We also found that the loss of this uORF has broad effects on the composition and phosphorylation status of the immunopeptidome that extended beyond the eIF2α axis. Collectively, our findings define the breath and potency of the highly conserved Ppp1r15a uORF and provide a paradigm for the design of uORF-based translation rheostat strategies. The ability to accurately control the dynamics of translation during sepsis will open new paths for the development of therapies at codon level precision.
2021-12-22 | GSE191262 | GEO
Project description:Eukaryotic cells rapidly reduce protein synthesis in response to various stress conditions. This can be achieved by the phosphorylation-mediated inactivation of a key translation initiation factor, eIF2. However, the persistent translation of certain mRNAs is required for deployment of an adequate stress response. We carried out ribosome profiling of cultured human cells under conditions of severe stress induced with sodium arsenite. Although this led to a ~4.5-fold general translational repression, the protein coding ORFs of certain individual mRNAs exhibited resistance to the inhibition. Nearly all resistant transcripts possess at least one efficiently translated uORF that repress translation of the main coding ORF under normal conditions. Site specific mutagenesis of two identified stress resistant mRNAs (PPP1R15B and IFRD1) demonstrated that a single uORF is sufficient for eIF2-mediated translation control in both cases. Phylogenetic analysis suggests that at least two regulatory uORFs (namely in SLC35A4 and MIEF1) encode functional protein products.
2015-01-27 | GSE55195 | GEO
Project description:The eIF2 initiation complex is central to maintaining a functional translation machinery. Extreme stress such as life-threatening sepsis exposes vulnerabilities in this tightly regulated system, resulting in an imbalance between the opposing actions of kinases and phosphatases on the main regulatory subunit eIF2α. Here, we report that translation shutdown is a hallmark of established sepsis-induced kidney injury brought about by excessive eIF2α phosphorylation and sustained by blunted expression of the counterregulatory phosphatase subunit Ppp1r15a. We determined that the blunted Ppp1r15a expression persists because of the presence of an upstream open reading frame (uORF). Overcoming this barrier with genetic approaches enabled the depression of Ppp1r15a, salvaged translation and improved kidney function in an endotoxemia model. We also found that the loss of this uORF has broad effects on the composition and phosphorylation status of the immunopeptidome that extended beyond the eIF2α axis. Collectively, our findings define the breadth and potency of the highly conserved Ppp1r15a uORF and provide a paradigm for the design of uORF-based translation rheostat strategies. The ability to accurately control the dynamics of translation during sepsis will open new paths for the development of therapies at codon level precision.
2022-09-28 | PXD030889 | Pride
Project description:Selective mRNA translation during eIF2 phosphorylation induces expression of IBTKalpha
| PRJNA237061 | ENA
Project description:The aim of this study is to investigate how eIF2 phosphorylation affects mRNA translation in erythroblasts. Ribosome profiling combined with RNA sequencing was used to determine translation initiation sites and ribosome density on individual transcripts.
2019-02-01 | GSE110618 | GEO
Project description:Protein stability buffers the cost of translation attenuation following eIF2⍺ phosphorylation
| PRJNA657554 | ENA
Project description:In times of cellular stress, such as during virus infections, the integrated stress response (ISR) blocks translation initiation through phosphorylation of the essential translation initiation factor eIF2. Phosphorylated eIF2 (p-eIF2) sequesters the eIF2-specific guanidine exchange factor (GEF) eIF2B, thereby preventing eIF2 recycling. Here we describe the first example of a viral ISR antagonist that inhibits the ISR at its most central step: the interplay between p-eIF2 and eIF2B. Using AP-MS, we determine that BW10 binds eIF2B. There, it selectively displaces eIF2B’s inhibitor p-eIF2 without affecting the association of its substrate eIF2. By this mechanism, BW10 renders cellular translation immune to regulation by eIF2 phosphorylation. Thus, under stress conditions BW10 creates the unprecedented situation of high levels of p-eIF2 coinciding with unimpaired translation.
2020-07-24 | PXD011879 | Pride
Project description:The molecular mechanisms linking the stress of unfolded proteins in the endoplasmic reticulum (ER stress) to glucose intolerance in obese animals are poorly understood. In this study enforced expression of a translation initiation 2α (eIF2α)-specific phosphatase, GADD34, was used to selectively compromise signaling in the eIF2(αP)-dependent arm of the ER unfolded protein response in liver of transgenic mice. The transgene resulted in lower liver glycogen levels and susceptibility to fasting hypoglycemia in lean mice and glucose tolerance and diminished hepato-steatosis in animals fed a high fat diet. Attenuated eIF2(αP) correlated with lower expression of the adipogenic nuclear receptor PPARγ and its upstream regulators, the transcription factors C/EBPα and C/EBPβ, in transgenic mouse liver, whereas eIF2α phosphorylation promoted C/EBP translation in cultured cells and primary hepatocytes. These observations suggest that eIF2(αP)-mediated translation of key hepatic transcriptional regulators of intermediary metabolism contributes to the detrimental consequences of nutrient excess. Keywords: genotype comparison The low expressing Ttr::Fv2E-Perk transgene (#58) was bred into the Atf4 knockout strain and the derivative compound heterozygous mice (in the mixed FvB/n; Swiss Webster background) were backcrossed to the Atf4+/- parental stock and Ttr::Fv2E-PERK positive siblings with Atf4+/+ and Atf4-/- genetypes were analyzed.
2011-12-23 | E-GEOD-11116 | biostudies-arrayexpress
Project description:Ribosome profiling uncovers selective mRNA translation associated with eIF2 phosphorylation in erythroid progenitors
| PRJNA434112 | ENA