Genome-wide analysis of transcriptome and translatome following eIF4A1 knockdown in MCF7 cells [Array]
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE58080 | GEO | 2014/12/01
SECONDARY ACCESSION(S): PRJNA251349
REPOSITORIES: GEO
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Project description:To identify which genes were regulated by mRNA helicase activity, the effect of eIF4A1 knockdown on the MCF7 cell transcriptome and translatome was determined. eIF4A1-dependent mRNAs were highly enriched for several classes of genes with oncogenic potential, which leads to a model whereby dysregulation of mRNA unwinding contribues to the malignant phenotype in breast cancer cells via preferential translation of a subset of genes.
2014-12-01 | GSE58111 | GEO
Project description:Oncogenic translational programmes are an emerging hallmark of cancer and often driven by dysregulation of signaling pathways including KRAS and mTORC that converge on the eukaryotic translation initiation (eIF) 4F complex. Altered eIF4F activity promotes translation of oncogene mRNAs that typically contain highly structured 5’UTRs rendering their translation strongly dependent on RNA unwinding by DEAD-box helicase eIF4A1 subunit of the eIF4F complex. In addition, eIF4A1 separately functions to load mRNA into the 43S pre-initiation complex (PIC), an essential step for the translation of cellular mRNA. While eIF4A1-dependent mRNAs have been widely investigated, it is still unclear if highly structured mRNAs recruit and activate eIF4A1 unwinding specifically. Here, we uncover that unwinding by eIF4A1 is activated in an RNA sequence-dependent manner in cells. Our data demonstrate that eIF4A1-dependent mRNAs contain specific RNA sequences, particularly enriched for polypurine-motifs, in their 5’UTR which recruit and specifically stimulate unwinding of local repressive RNA structure by eIF4A1 in an RNA sequence-dependent manner to facilitate translation. Mechanistically, we show that polypurine-rich sequences trigger the formation of RNA sequence-specific multimeric eIF4A1-complexes, assembled of catalytically distinct eIF4A1 subunits, the joint activity of which enhances RNA unwinding activity. Together with our structural data, we describe a model in which conformational changes within eIF4A1 and the RNA through the process of eIF4A1 multimerisation, lead to an optimal interaction of eIF4A1-unwinding subunits with the structured RNA region which enhances unwinding. Hence, we conclude that RNA sequences in addition to protein cofactors contribute to the regulation of cellular eIF4A1 function and promotion of translation of eIF4A1-unwinding dependent mRNAs.
2023-01-17 | PXD034343 | Pride
Project description:We subjected MCF7 cells to starvation with 0.5% charcoal treated serum for 48h and then we added 17-beta estradiol (E2) at final concentration of 10 nM, profiling before and after 60 minutes of treatment the transcriptome and the translatome, coming from the polysomal pool of mRNAs after sucrose gradient separation. Comparison of translatome profile changes with corresponding transcriptome profile changes represents a way of studying translational control networks and the degree of concordance between cellular controls affecting mRNA abundance and cellular controls affecting mRNA availability to translation. It is well known that E2 is a strong transcriptional regulator, while its translational control activity is less characterized. To provide a direct experimental evaluation of E2 induced translational regulation, we compared translatome and transcriptome profiles of E2 treated cells. Keywords: polysomal profiling, translatome profiling, polysomal RNA, translational control, translational profiling, polysome profiling, post-transcriptional regulation, estradiol stimulation, estrogen receptor. The comparison between transcriptional and polysomal profiling was used for the discovery of general and mRNA-specific changes in the translation state of the serum starved MCF7 cells transcriptome in response to E2 stimulus. To identify translationally regulated mRNA molecules, gene expression signals derived from the polysomal populations were compared by microarrays analysis to those obtained from unfractionated total RNAs. Polysomal RNA and total RNA were isolated from MCF7 cells serum starved and treated with E2. Cells lysates were collected before (t = 0 min) and after (t = 60 min) E2 treatment. All experiments were run in quadruplicates.
2010-12-31 | E-GEOD-22012 | biostudies-arrayexpress
Project description:Hippuristanol (Hipp) is a natural product that selectively inhibits protein synthesis by targeting eukaryotic initiation factor (eIF) 4A, a DEAD-box RNA helicase required for ribosome recruitmentt o mRNA templates. Using a CRISPR/Cas9-based variomics screen, we identify functional eIF4A1 Hipp-resistant alleles, which in turn allow us to link the translation-inhibitory and cytotoxic properties of Hipp to eIF4A1 target-engagement. Genome-wide translational profiling in the absence or presence of Hipp (~EC50) were undertaken and our validation studies provided insight into structure-activity relationships of eIF4A-dependent mRNAs.
2020-08-05 | GSE151687 | GEO
Project description:Several genome-wide transcriptome analyses that focused on p53-induced cellular responses in many cellular contexts have continued to expand the already vast p53-regulated transcriptional networks. To investigate post-transcriptional controls as an additional dimension of p53-directed gene expression responses we performed translatome analysis by polysomal profiling on MCF7 cells treated with Doxorubicin and Nutlin-3a. A comparison between the transcriptome and the translatome revealed a large number of uncoupled genes, whose transcription changes did not correlate with translation changes. Overall, we establish p53 as a master regulator of translational control and identify many p53 target genes affecting translation that can contribute to p53-dependent cellular responses. Keywords: p53, transcriptome, translatome, polysomal RNA, subpolysomal RNA, uncoupling, Doxorubicin, Nutlin-3a Total RNA (tot) was extracted from MCF7 vector cells after 16h of treatment with Doxorubicin (1.5uM) and Nutlin-3a (10uM) or DMSO (solvent, as control treatment). Polysomal profiling was performed after the same conditions. We collected all subpolysomal mRNA fractions (sub) and the polysomal ones (pol) after sucrose gradient fractionation of cytoplasmic lysates to analyze separately mRNAs that are not actively translated from those that are considered in active translation, respectively. Experiments were performed in three biological replicates.
2014-04-17 | E-GEOD-50650 | biostudies-arrayexpress
Project description:We subjected MCF7 cells to starvation with 0.5% charcoal treated serum for 48h and then we added 17-beta estradiol (E2) at final concentration of 10 nM, profiling before and after 60 minutes of treatment the transcriptome and the translatome, coming from the polysomal pool of mRNAs after sucrose gradient separation. Comparison of translatome profile changes with corresponding transcriptome profile changes represents a way of studying translational control networks and the degree of concordance between cellular controls affecting mRNA abundance and cellular controls affecting mRNA availability to translation. It is well known that E2 is a strong transcriptional regulator, while its translational control activity is less characterized. To provide a direct experimental evaluation of E2 induced translational regulation, we compared translatome and transcriptome profiles of E2 treated cells. Keywords: polysomal profiling, translatome profiling, polysomal RNA, translational control, translational profiling, polysome profiling, post-transcriptional regulation, estradiol stimulation, estrogen receptor.
2010-12-31 | GSE22012 | 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
Project description:Active translatome profiling with RiboLace in MCF7 cells
| PRJNA445552 | ENA
Project description:Several genome-wide transcriptome analyses that focused on p53-induced cellular responses in many cellular contexts have continued to expand the already vast p53-regulated transcriptional networks. To investigate post-transcriptional controls as an additional dimension of p53-directed gene expression responses we performed translatome analysis by polysomal profiling on MCF7 cells treated with Doxorubicin and Nutlin-3a. A comparison between the transcriptome and the translatome revealed a large number of uncoupled genes, whose transcription changes did not correlate with translation changes. Overall, we establish p53 as a master regulator of translational control and identify many p53 target genes affecting translation that can contribute to p53-dependent cellular responses. Keywords: p53, transcriptome, translatome, polysomal RNA, subpolysomal RNA, uncoupling, Doxorubicin, Nutlin-3a
2014-04-17 | GSE50650 | GEO
Project description:Authentication of Hippuristanol-eIF4A1 Target Engagement Facilitates Identification of eIF4A1 Helicase Dependencies within 5’ Leader Regions
| PRJNA636959 | ENA