Saccharomyces cerevisiae
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ABSTRACT:
PROVIDER: PRJNA345383 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Nat1 (also known as p97/Dap5/Eif4g2) is a ubiquitously expressed cytoplasmic protein that is homologous to the C-terminal two thirds of eukaryotic translation initiation factor 4G (also known as Eif4g1). We previously showed that Nat1-null mouse embryonic stem cells (mESCs) were resistant to differentiation. In the current study, we found that Nat1 and Eif4g1 share many binding proteins, such as Eif3s, Eif4s and ribosomal proteins. However, Nat1 did not bind to Eif4e or poly A binding proteins, which are critical for cap-dependent translation initiation. In contrast, Nat1 binds to Eif2s, Fmr and related proteins, and Prrc2 proteins more preferentially than does Eif4g1. We also found that Nat1-null mESCs possess a status partially similar to ground state, which is established in wild-type mES cells when treated with inhibitors of the ERK and GSK3 signaling pathways. In Nat1-null mESCs, the ERK pathway is suppressed even without inhibitors. Ribosomal profiling revealed that translation of Map3k3 and Sos1 is suppressed in the absence of Nat1. Forced expression of Map3k3 induced differentiation of Nat1-null mESCs. These data collectively showed that Nat1 is involved in translation of proteins that are required for cell differentiation.
2017-01-06 | GSE89011 | GEO
Project description:Nat1 (also known as p97/Dap5/Eif4g2) is a ubiquitously expressed cytoplasmic protein that is homologous to the C-terminal two thirds of eukaryotic translation initiation factor 4G (also known as Eif4g1). We previously showed that Nat1-null mouse embryonic stem cells (mESCs) were resistant to differentiation. In the current study, we found that Nat1 and Eif4g1 share many binding proteins, such as Eif3s, Eif4s and ribosomal proteins. However, Nat1 did not bind to Eif4e or poly A binding proteins, which are critical for cap-dependent translation initiation. In contrast, Nat1 binds to Eif2s, Fmr and related proteins, and Prrc2 proteins more preferentially than does Eif4g1. We also found that Nat1-null mESCs possess a status partially similar to ground state, which is established in wild-type mES cells when treated with inhibitors of the ERK and GSK3 signaling pathways. In Nat1-null mESCs, the ERK pathway is suppressed even without inhibitors. Ribosomal profiling revealed that translation of Map3k3 and Sos1 is suppressed in the absence of Nat1. Forced expression of Map3k3 induced differentiation of Nat1-null mESCs. These data collectively showed that Nat1 is involved in translation of proteins that are required for cell differentiation.
2017-01-06 | GSE89007 | GEO
Project description:Translation factors eIF4E and eIF4G form eIF4F, which binds to mRNAs to promote ribosome recruitment and translation initiation. We were interested in analysing the effects of stresses on eIF4F interactions with individual mRNAs. We used a RIP-seq approach to assess how mRNA associations with eIF4E, eIF4G1 and eIF4G2 change in response to three stresses: 1) addition of hydrogen peroxide; 2) amino acids withdrawal; and, 3) glucose withdrawal. We find that acute stress leads to changes in eIF4FmRNA interactions that are shared among each factor and across the stresses imposed.
2017-10-11 | E-MTAB-5836 | biostudies-arrayexpress
Project description:RNA binding protein LARP1 binds preferentially to mRNAs containing a 5' Tract of Oligo Pyrimidines (5'-TOP) motif
2017-11-30 | GSE99502 | GEO
Project description:Nat1 (also known as p97/Dap5/Eif4g2) is a ubiquitously expressed cytoplasmic protein that is homologous to the c-terminal two thirds of eukaryotic translation initiation factor 4G (also known as Eif4g1). We previously showed that Nat1-null mouse embryonic stem cells (mESCs) were resistant to differentiation. In the current study, we found that NAT1 and eIF4G1 share many binding proteins, such as eIF3, eIF4A and ribosomal proteins. However, NAT1did not bind to eIF4E or poly A binding proteins, which are critical for cap-dependent translation initiation. In contrast, compared to eIF4G1, NAT1 preferentially interacts with eIF2, FMR and related proteins, and especially PRRC2 family members. We also found that Nat1-null mESCs possess a transcriptional profile similar, though not identical, to ground state, which is established in wild-type mES cells when treated with inhibitors of the ERK and GSK3 signaling pathways. In Nat1-null mESCs, the ERK pathway is suppressed even without inhibitors. Ribosome profiling revealed that translation of Map3k3 and Sos1 is suppressed in the absence of Nat1. Forced expression of Map3k3 induced differentiation of Nat1-null mESCs. These data collectively showed that Nat1 is involved in translation of proteins that are required for cell differentiation.
2017-01-06 | GSE89600 | GEO
Project description:Start codon recognition by the 48S complex is a critical step in translation. However, understanding the in vivo initiation and its regulation at a global scale is limited. Here, we analyzed translation complex profiling (TCP-seq) data to determine the impact of eIF4G1-eIF1 inhibition and the 48S organization. Our analysis provides the first global view of leaky scanning and reveal the central roles of mRNA features and eIF4G1-eIF1 in its regulation. Specifically, non-leaky genes are enriched with a Kozak bearing a C at -1 position while those with short 5’ UTR with TISU. Additionally, the stability of the 48S complex and its integrity during scanning are impaired upon eIF4G1-eIF1 inhibition. Detailed analysis of initiation site footprints revealed three main classes conserved from yeast to human. Our analysis provides a general overview of AUG selection and evidence for conformational rearrangements in vivo.
2024-03-27 | GSE226132 | GEO
Project description:Translation initiation factor 4G (eIF4G) is an integral component of the eIF4F complex which is key to translation initiation for most eukaryotic mRNAs. Many eIF4G isoforms have been described in diverse eukaryotic organisms but we currently have a poor understanding of their functional roles and whether they regulate translation in an mRNA specific manner. The yeast Saccharomyces cerevisiae expresses two eIF4G isoforms, eIF4G1 and eIF4G2, that have previously been considered as functionally redundant with any phenotypic differences arising due to alteration in eIF4G expression levels. Using homogenic strains that express eIF4G1 or eIF4G2 as the sole eIF4G isoforms at comparable expression levels to total eIF4G, we show that eIF4G1 is specifically required to mediate the translational response to oxidative stress. We use quantitative proteomics to show that eIF4G1 promotes oxidative stress-specific proteome changes.
2023-10-24 | PXD041682 | Pride
Project description:The cellular response to DNA damage is mediated through multiple pathways that regulate and coordinate DNA repair, cell cycle arrest and cell death. We show that the DNA damage response (DDR) induced by ionizing radiation (IR) is coordinated in breast cancer cells by selective mRNA translation mediated by high levels of translation initiation factor eIF4G1. Increased expression of eIF4G1, common in breast cancers, was found to selectively increase translation of mRNAs involved in cell survival and the DDR, preventing autophagy and apoptosis (Survivin, HIF1α, XIAP), promoting cell cycle arrest (GADD45a, p53, ATRIP, Chk1) and DNA repair (53BP1, BRCA1/2, PARP, Rfc2-5, ATM, MRE-11, others). Reduced expression of eIF4G1, but not its homolog eIF4G2, greatly sensitizes cells to DNA damage by IR, induces cell death by both apoptosis and autophagy, and significantly delays resolution of DNA damage foci with little reduction of overall protein synthesis. While some mRNAs selectively translated by higher levels of eIF4G1 were found to use internal ribosome entry site (IRES)-mediated alternate translation, most do not. The latter group shows significantly reduced dependence on eIF4E for translation, facilitated by an enhanced requirement for eIF4G1. Increased expression of eIF4G1 therefore promotes specialized translation of survival, growth arrest and DDR mRNAs that are important in cell survival and DNA repair following genotoxic DNA damage. The purpose of this study was to identify mRNAs that are selectively increased in translation by high levels of the initiation factor eIF4G1, which occurs in many advanced human cancers, in response to DNA damage caused by ionizing radiation, Polysome isolation was performed by separation of ribosome-bound mRNAs in sucrose gradients. Beckman Ultra-Clear centrifuge tubes were loaded with 5.5 ml of 50% sucrose in low salt buffer (LSB: 200 mM Tris pH7.4 in DEPC H2O, 100 mM NaCl, 30 mM MgCl2) with 1:1000 RNasin (Fermentas) and 100 μg/mL cycloheximide (CHX) in ethanol and incubated at 4°C horizontally overnight. Media was removed from cell cultures, replaced with media containing 100 μg/mL CHX, cells incubated at 37°C for 10 min to halt protein synthesis, and trypsinized in trypsin/EDTA containing 100 μg/mL CHX. Cells were washed twice in PBS containing CHX, RNasin and Roche complete EDTA-free protease inhibitor tablet, lysed in LSB with CHX and RNasin. Lysates were added to a Dounce homogenizer and incubated on ice for 3 min before addition of Triton detergent buffer (1.2% Triton N-100, 0.2M sucrose in LSB) and homogenization. Samples were transferred to cold sterile Eppendorf centrifuge tubes and centrifuged at 13,000 x RPM for 10 min at 4°C. Post-nuclear supernatants were transferred to centrifuge tubes containing 100 μL Heparin solution (10 mg/mL heparin, 1.5M NaCl in LSB) with RNasin and CHX, applied to a sucrose gradient. Gradients were centrifuged at 36K RPM at 4°C for 2 h, and supernatants recovered with an ISCO-UV fractionator. Samples were recovered into Eppendorf centrifuge tubes containing 40 μL RNase-free 0.5M EDTA and kept on ice. One volume acidic phenol-chloroform was added to each sample, which were then mixed and centrifuged at 10,000 x g for 15 min. The acidic phenol-chloroform extraction was repeated with the aqueous phase, which was then extracted twice via chloroform extraction. RNA was precipitated at -20°C overnight by addition of isopropanol with 0.1 vol NaOAc, pH5.2. The following day, RNA pellets were recovered by centrifugation, washed with 70% ethanol, air-dried and resuspended in sterile H2O. RNA from fractions was then pooled based on their relative rate of translation, with fractions containing 4 or more ribosomes considered heavily translated and used for gene chip analysis. The RNA quality was examined via the Agilent Technologies kit.
2012-10-17 | E-GEOD-41627 | biostudies-arrayexpress
Project description:The cellular response to DNA damage is mediated through multiple pathways that regulate and coordinate DNA repair, cell cycle arrest and cell death. We show that the DNA damage response (DDR) induced by ionizing radiation (IR) is coordinated in breast cancer cells by selective mRNA translation mediated by high levels of translation initiation factor eIF4G1. Increased expression of eIF4G1, common in breast cancers, was found to selectively increase translation of mRNAs involved in cell survival and the DDR, preventing autophagy and apoptosis (Survivin, HIF1α, XIAP), promoting cell cycle arrest (GADD45a, p53, ATRIP, Chk1) and DNA repair (53BP1, BRCA1/2, PARP, Rfc2-5, ATM, MRE-11, others). Reduced expression of eIF4G1, but not its homolog eIF4G2, greatly sensitizes cells to DNA damage by IR, induces cell death by both apoptosis and autophagy, and significantly delays resolution of DNA damage foci with little reduction of overall protein synthesis. While some mRNAs selectively translated by higher levels of eIF4G1 were found to use internal ribosome entry site (IRES)-mediated alternate translation, most do not. The latter group shows significantly reduced dependence on eIF4E for translation, facilitated by an enhanced requirement for eIF4G1. Increased expression of eIF4G1 therefore promotes specialized translation of survival, growth arrest and DDR mRNAs that are important in cell survival and DNA repair following genotoxic DNA damage. The purpose of this study was to identify mRNAs that are selectively increased in translation by high levels of the initiation factor eIF4G1, which occurs in many advanced human cancers, in response to DNA damage caused by ionizing radiation,
2012-10-17 | GSE41627 | GEO
Project description:Eukaryotic translation initiation factor (eIF) 4A — a DEAD-box RNA-binding protein — plays an essential role in translation initiation. Recent reports have suggested helicase-dependent and helicase-independent functions for eIF4A, but the multifaceted roles of eIF4A have not been fully explored. Here, we show that eIF4A1 enhances translational repression during the inhibition of mechanistic target of rapamycin complex 1 (mTORC1), an essential kinase complex controlling cell proliferation. RNA pulldown followed by sequencing revealed that eIF4A1 preferentially binds to mRNAs containing terminal oligopyrimidine (TOP) motifs (TOP mRNAs), whose translation is rapidly repressed upon mTORC1 inhibition. This selective interaction depends on a La-related RNA-binding protein, LARP1. Ribosome profiling revealed that deletion of EIF4A1 attenuated the translational repression of TOP mRNAs upon mTORC1 inactivation. Moreover, eIF4A1 increases the affinity between TOP mRNAs and LARP1 and thus ensures stronger translational repression upon mTORC1 inhibition. Our data show the multimodality of eIF4A1 in modulating protein synthesis through an inhibitory binding partner and provide a unique example of the repressive role of a universal translational activator.
2024-02-13 | GSE184247 | GEO