Crosstalk between eIF2α and eEF2 phosphorylation pathways optimizes translational arrest in response to oxidative stress
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA565395 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:The cellular stress response triggers a cascade of events leading to transcriptional reprogramming and a transient inhibition of global protein synthesis, which is thought to be mediated by phosphorylation of eukaryotic initiation factor-2α (eIF2α). Using mouse embryonic fibroblasts (MEFs) and the fission yeast S. pombe, we report that rapid translational arrest and cell survival in response to hydrogen peroxide-induced oxidative stress do not rely on eIF2a kinases and eIF2a phosphorylation. Rather H2O2 induces a block in elongation through phosphorylation of eukaryotic elongation factor 2 (eEF2). Kinetic and dose-response analyses uncovered crosstalk between the eIF2a and eEF2 phosphorylation pathways, indicating that, in MEFs, eEF2 phosphorylation initiates the acute shutdown in translation, which is maintained by eIF2a phosphorylation. Our results challenge the common conception that eIF2a phosphorylation is the primary trigger of translational arrest in response to oxidative stress and point to integrated control that may facilitate the survival of cancer cells.
2019-09-14 | GSE137409 | GEO
Project description: Not available
| S-EPMC6823656 | biostudies-literature
Project description:The integrated stress response (ISR) is critical for cell survival under stress. In response to diverse environmental cues, eIF2αbecomes phosphorylated, engendering a dramatic change in mRNA translation. The activation of ISR plays a pivotal role in the early embryogenesis but the eIF2-dependent translational landscape in pluripotent embryonic stem cells (ESC) is largely unexplored. We employ a multi-omics approachconsisting of ribosome profiling, proteomics, and metabolomics inwild-type(eIF2α+/+)andphosphorylation-deficient mutant eIF2α(eIF2αA/A)mouse ESCs (mESCs) to investigate phosphorylated (p)-eIF2α-dependent translational control of naïve pluripotency. We show a transient increase in p-eIF2α in the naïve epiblast layer of E4.5 embryos. Absence of eIF2α phosphorylation engenders an exit from naive pluripotency following 2i (two chemical inhibitors of MEK1/2 and GSK3α/β) withdrawal. p-eIF2α controls translation of mRNAs encoding proteins which govern pluripotency, chromatin organization, and glutathione synthesis.Thus, p-eIF2αacts as a key regulator of the naïve pluripotency gene regulatory network.
2023-12-29 | GSE248724 | GEO
Project description:The integrated stress response (ISR) is critical for cell survival under stress. In response to diverse environmental cues, eIF2αbecomes phosphorylated, engendering a dramatic change in mRNA translation. The activation of ISR plays a pivotal role in the early embryogenesis but the eIF2-dependent translational landscape in pluripotent embryonic stem cells (ESC) is largely unexplored. We employ a multi-omics approachconsisting of ribosome profiling, proteomics, and metabolomics inwild-type(eIF2α+/+)andphosphorylation-deficient mutant eIF2α(eIF2αA/A)mouse ESCs (mESCs) to investigate phosphorylated (p)-eIF2α-dependent translational control of naïve pluripotency. We show a transient increase in p-eIF2α in the naïve epiblast layer of E4.5 embryos. Absence of eIF2α phosphorylation engenders an exit from naive pluripotency following 2i (two chemical inhibitors of MEK1/2 and GSK3α/β) withdrawal. p-eIF2α controls translation of mRNAs encoding proteins which govern pluripotency, chromatin organization, and glutathione synthesis.Thus, p-eIF2αacts as a key regulator of the naïve pluripotency gene regulatory network.
2023-12-29 | GSE248725 | GEO
Project description:We recently identified ISRIB as a potent inhibitor of the integrated stress response (ISR). ISRIB renders cells resistant to the effects of eIF2α phosphorylation and enhances long-term memory in rodents (10.7554/eLife.00498). Here we show by genome-wide in vivo ribosome profiling that translation of a restricted subset of mRNAs is induced upon ISR activation. ISRIB substantially reversed the translational effects elicited by phosphorylation of eIF2α and induced no major changes in translation or mRNA levels in unstressed cells. eIF2α phosphorylation-induced stress granule (SG) formation was blocked by ISRIB. Strikingly, ISRIB addition to stressed cells with pre-formed SGs induced their rapid disassembly, liberating mRNAs into the actively translating pool. Restoration of mRNA translation and modulation of SG dynamics may be an effective treatment of neurodegenerative diseases characterized by eIF2α phosphorylation, SG formation and cognitive loss. Ribosome profiling with paired RNA-seq
2015-02-27 | E-GEOD-65778 | biostudies-arrayexpress
Project description:We recently identified ISRIB as a potent inhibitor of the integrated stress response (ISR). ISRIB renders cells resistant to the effects of eIF2α phosphorylation and enhances long-term memory in rodents (10.7554/eLife.00498). Here we show by genome-wide in vivo ribosome profiling that translation of a restricted subset of mRNAs is induced upon ISR activation. ISRIB substantially reversed the translational effects elicited by phosphorylation of eIF2α and induced no major changes in translation or mRNA levels in unstressed cells. eIF2α phosphorylation-induced stress granule (SG) formation was blocked by ISRIB. Strikingly, ISRIB addition to stressed cells with pre-formed SGs induced their rapid disassembly, liberating mRNAs into the actively translating pool. Restoration of mRNA translation and modulation of SG dynamics may be an effective treatment of neurodegenerative diseases characterized by eIF2α phosphorylation, SG formation and cognitive loss.
2015-02-27 | GSE65778 | GEO
Project description:TgIF2K-B is an eIF2α kinase in Toxoplasma gondii that responds to oxidative stress and optimizes pathogenicity
| PRJNA664394 | ENA
Project description:Trypanosomatids regulate gene expression mainly at the post-transcriptional level through processing, exporting and stabilizing mRNA and control of translation. In most eukaryotes, protein synthesis is regulated by phosphorylation of eukaryotic initiation factor 2 (eIF2) at serine 51. Phosphorylation halts overall translation by decreasing availability of initiator tRNAmet to form translating ribosomes. In trypanosomatids the N-terminus of eIF2α is extended with threonine 169 the homologous phosphorylated residue and eIF2α phosphorylation increases in proliferative intracellular forms prior to differentiation into trypomastigotes. Here we analyse the proteome changes in epimatigotes upon eIF2αT169A mutation and knock-out of the kinase TcK11, an ortolog of the general control nonderepressible 2 (GCN2)kinases which have been implicated in eukaryotic eIF2α ser51 phosphorylation.
2020-07-06 | PXD018761 | Pride
Project description:Stress granules are dynamic cytoplasmic ribonucleoprotein granules that assemble in response to cellular stress. Aberrant formation of stress granules has been linked to neurodegenerative diseases. However, the molecular mechanisms underlying the initiation of stress granules remain elusive. Here we report that the brain-enriched protein kinase FAM69C promotes stress granule assembly through phosphorylation of eukaryotic translation initiation factor 2 (eIF2α). FAM69C physically interacts with eIF2α and functions as a stress-specific kinase for eIF2α, leading to stress-induced protein translation arrest and stress granule assembly. Primary microglia derived from Fam69c knockout mice exhibit aberrant stress granule assembly in response to oxidative stress and ATP. Defective stress granule assembly in microglia correlates with the formation of ASC specks and NLRP3 inflammasome activation, whereas induction of stress granule precludes inflammasome formation. Consistently, increased NLRP3 levels, caspase-1 cleavage and Il18 expression corroborate microglia-associated neuroinflammation in aged Fam69c knockout mice. Our study demonstrates that FAM69C is critical for stress granule assembly and suggests its role in the regulation of microglia function.
2023-04-21 | PXD037697 | Pride
Project description:Translational control of gene expression is an important regulator of adult stem cell quiescence, activation and self-renewal. In skeletal muscle, quiescent satellite cells maintain low levels of protein synthesis, mediated in part through the phosphorylation of eIF2α (P-eIF2α). Pharmacological inhibition of the eIF2α phosphatase with the small molecule sal003 maintains P-eIF2α and permits the expansion of satellite cells ex vivo. Paradoxically, P-eIF2α also increases the translation of specific mRNAs, which is mediated by P-eIF2α-dependent read-through of inhibitory upstream open reading frames (uORFs). Here, we ask whether P-eIF2α-dependent mRNA translation enables expansion of satellite cells. Using transcriptomic and proteomic analyses, we show a number of genes associated with the assembly of the spindle pole to be upregulated at the level of protein, without corresponding change in mRNA levels, in satellite cells expanded in the presence of sal003. We show that uORFs in the 5′ UTR of mRNA for the mitotic spindle stability gene Tacc3 direct P-eIF2α-dependent translation. Satellite cells deficient for TACC3 exhibit defects in expansion, self-renewal and regeneration of skeletal muscle.
2021-01-14 | GSE164774 | GEO