Similar Datasets
Project description:Compared protein synthesis in Gcn2 WT vs Gcn2 KO murine PDAC cells (KRPC) in amino acid-replete or leucine-free media.
2022-10-13 | PXD028143 | Pride
Project description:GCN2 adapts the proteome to scavenging-dependent growth
| PRJNA634769 | ENA
Project description:La-related protein 1 (LARP1) has been identified as a key translational inhibitor of terminal oligopyrimidine tract (TOP) mRNAs downstream of the nutrient sensing protein kinase complex, mTORC1. LARP1 exerts this inhibitory effect on TOP mRNA translation by binding to the mRNA cap and the adjacent 5’TOP motif, resulting in the displacement of the eIF4E complex from TOP mRNAs. In the present study, we identify a second nutrient sensing kinase GCN2 that converges on LARP1 to control TOP mRNA translation. GCN2 inhibits TOP mRNA translation via ATF4-dependent transcriptional induction of LARP1 mRNAs and GCN1-mediated recruitment of LARP1 to stalled ribosomes. We performed ATF4 ChIP-seq experiments in both WT and GCN2 KO MEFs with or without leucine deprivation.
2022-08-31 | GSE166590 | GEO
Project description:GCN2 (General Control Nonderepressible 2) is a serine/threonine-protein kinase that controls mRNA translation in response to amino acid availability. Here we show that production and clearance of erythrocytes are controlled by GCN2. Our data highlight the importance of tissue-resident macrophages as the primary cell type mediating this effect. During different stress conditions, such as hemolysis, amino acid deficiency or hypoxia, GCN2 knockout (GCN2-/-) mice displayed resistance to anemia as compared to wild-type (GCN2+/+) mice. GCN2-/- liver macrophages display defective erythrophagocytosis and lysosome maturation. Molecular analysis of GCN2-/- cells indicates that the ATF4-NRF2 pathway is a critical downstream mediator of GCN2 in regulating RBC clearance and iron recycling. We performed NRF2 (Nfe2l2) ChIP-seq experiments in both WT and GCN2 KO MEFs with or without leucine deprivation.
2022-12-01 | GSE188460 | GEO
Project description:Background: Arginine deprivation was shown previously to inhibit retinoblastoma cell proliferation and induce cell death in vitro. However, the mechanisms by which retinoblastoma cells respond to arginine deprivation remain to be elucidated. Methods: Human derived retinoblastoma cell lines Y79 and WERI-Rb-1 were exposed to arginine depletion, and the effects on inhibiting cell growth and survival were evaluated. The study investigated potential mechanisms, including autophagy, cell cycle arrest, and apoptosis. Moreover, the roles of GCN2 and mTOR signaling pathways in these processes were examined. Results: We demonstrated that arginine deprivation effectively inhibited the growth of retinoblastoma cells in vitro. This treatment caused an increase in autophagic response. Additionally, we found that prolonged arginine shortage induced G2 cell cycle arrest and was accompanied by an increase in early apoptotic cells. Importantly, arginine depletion also caused an activation of GCN2 and an inhibition of mTOR signaling. We also discovered that the activation of SLC7A11 was regulated by GCN2 upon arginine deprivation. Knockdown of SLC7A11 rendered retinoblastoma cells partially resistant to arginine deprivation. Furthermore, we found that knockdown of GCN2 led to a decrease in autophagic response in WERI-Rb-1 cells and arrested more cells in S phase, which was accompanied by fewer apoptotic cells. Moreover, knockdown of GCN2 caused constant expression of ATF4, phosphorylation of 70S6K, and 4E-BP1 regardless of arginine deprivation. Conclusions: Collectively, our findings suggest that the GCN2-SLC7A11 axis regulates cell growth and survival upon arginine deprivation through coordinating autophagy, cell cycle arrest, and apoptosis in retinoblastoma cells. This work paves the way for the development of a novel treatment for retinoblastoma.
2024-10-28 | GSE278276 | GEO
Project description:Amino acid availability regulates translation through the action of the GCN2 and mTORC1 pathways. Low amino acids activate the eIF2α kinase GCN2 through binding of uncharged tRNAs to a histidyl-tRNA synthetase−related regulatory domain. Once activated GCN2 phosphorylates eIF2α, inhibiting ternary complex formation and translation initiation. Recent studies show that mTORC1 is particularly sensitive to arginine and leucine status, with a deprivation of these amino acids leading to a strong inhibition of mTORC1 that prevents the phosphorylation and inactivation of the translational repressor 4EBP1. Though amino acids are known regulators of translation, the effects that deficiencies of specific amino acids have on translation have yet to be determined. We demonstrate that deprivation of leucine or methionine results in large inhibitory effects on translation initiation and on polysome formation that are not replicated by overexpressing non-phosphorylatable 4EBP1 or a phosphomimetic eIF2α. Our results demonstrate that a lack of either leucine or methionine has a major impact on mRNA translation, though they act by quite different mechanisms. Leucine deprivation appears to primarily inhibit ribosome loading, whereas methionine deprivation appears to primarily impair start site recognition. These data point to a unique regulatory effect that methionine status has on translation initiation.
2018-04-04 | GSE112643 | GEO
Project description:We analyzed the transcriptomes of Wild-type and GCN2-deficient mouse embryonic stem cells after 3h of arginine or leucine starvation.
2024-01-01 | GSE195470 | GEO
Project description:Diverse environmental insults induce the integrated stress response (ISR), which features eIF2 phosphorylation and translational control that serves to restore protein homeostasis. The eIF2 kinase GCN2 is a first responder in the ISR that is activated by amino acid depletion and other unrelated stresses. Two processes are suggested to trigger an ordered process of GCN2 activation during stress: GCN2 monitoring stress via accumulating uncharged tRNAs or by stalled and colliding ribosomes. Our results suggest that while ribosomal collisions are indeed essential for GCN2 activation in response to translational elongation inhibitors, conditions that trigger deacylation of tRNAs activate GCN2 via its direct association with affected tRNAs. Both process require the GCN2 regulatory domain related to histidyl tRNA synthetases. GCN2 activation by UV irradiation features lowered amino acids and increased uncharged tRNAs and ribosome collisions are dispensable. We conclude that there are multiple mechanisms that activate GCN2 during diverse stresses.
2024-03-06 | GSE239867 | GEO
Project description:General control nonderepressible 2 (GCN2) phosphorylates eIF2α, regulating translation in response to nutritional stress. Here, we show that mammalian ribosomes are potent GCN2 activators. Hydrogen/deuterium exchange–mass spectrometry (HDX-MS) showed GCN2 interacting with domain II of the uL10 P-stalk protein. The P-stalk is a uL10/P12/P22 pentameric complex that is part of the ribosomal GTPase-associated center. Recombinant human P-stalk greatly stimulates GCN2. Both domain II of uL10 and the C-terminal tails of P1 and P2 are necessary for maximal GCN2 activation. On actively translating ribosomes, the C-terminal tails of P1 and P2 are sequestered by elongation factors, suggesting P-stalk availability could link translational stress to GCN2 activation.
2019-05-24 | PXD013051 | Pride
Project description:General translational repression is predicted as a key process to reduce energy consumption under hypoxia. We have previously showed that mRNA loading onto polysome is reduced in Arabidopsis under submergence. Here, we showed that plant stress activated GCN2 (general control nonderepressible 2) can phosphorylate eIF2a (Eukaryotic Initiation Factor 2a) in Arabidopsis under submergence, and this process is reversible after desubmergence. Compared to the wild-type, the reduction in polysome loading during submergence was less severe in the gcn2 mutant. Transgenic lines overexpressing GCN2 had more ATP and conferred better tolerance under submergence, suggesting that GCN2 might modulate the dynamics of translation to adjust the energy homeostasis under hypoxia. Interestingly, GCN2-eIF2a signaling was activated by ethylene under submergence. However, GCN2 activity was not affected in ein2-5 and eil1ein3 under submergence, suggesting that GCN2 activity was regulated by noncanonical ethylene signaling. In addition, the polysome loading was retained in both ein2-5 and etr1-1 under submergence, implying that ethylene modulated the dynamic translation under submergence via EIN2 and GCN2. Notably, our NGS analysis also demonstrated that EIN2 and GCN2 regulated the translation of 23 core hypoxia genes as well as 53% translational repressed genes under submergence. On the other hand, EIN2 and GCN2 also affected the expression of genes involved in hypoxic response, ethylene response, biotic stress and negative regulation of cytokinin signaling. Taken together, these demonstrated that entrapped ethylene triggers GCN2 and EIN2 to ensure the translation of stress required proteins under submergence and also provide a step stone for future investigation how eukaryotic cells modulate the translation to response for the changeable environments.
2022-06-08 | GSE149414 | GEO