Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1049869 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR27132528_1.fastq.gz | Fastqsanger.gz | |||
| SRR27132528_2.fastq.gz | Fastqsanger.gz | |||
| SRR27132529_1.fastq.gz | Fastqsanger.gz | |||
| SRR27132529_2.fastq.gz | Fastqsanger.gz | |||
| SRR27132530_1.fastq.gz | Fastqsanger.gz |
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Project description:Translational dysregulation is an emerging hallmark of cancer, and increased activity of the mRNA helicase eIF4A is associated with poor survival in malignancies. This is believed to be due to the unwinding of secondary structures within the 5’UTRs of oncogenic mRNAs, with studies showing that in general eIF4A-dependent mRNAs have longer 5’UTRs with more stable secondary structures, yet our ability to predict eIF4A-dependency from 5’UTR properties alone remains poor. We therefore used Structure-seq 2 to measure transcriptome-wide changes in RNA structure in MCF7 cells, following eIF4A inhibition with hippuristanol. This technique measures the single-strandedness of RNA by specific and rapid methylation of single-stranded adenosines and cytosines with Dimethyl Sulphate (DMS). When paired with polysome profiling data to identify which mRNAs are most translationally repressed, we can identify the structural determinants of eIF4A-dependency. Upon eIF4A inhibition, both 5’UTRs and CDSs become generally more structured, while overall this was not observed for 3’UTRs. This was most pronounced in CDSs, supporting recent findings that the ribosome sculpts RNA structure in this region. 5’UTRs are generally more structured at their 5’ ends and highly translated mRNAs are less structured just upstream of the CDS. Following eIF4A inhibition, the 5’UTR is remodelled. eIF4A-dependent mRNAs have greater localised gains of structure. The degree of these structural changes is strongly correlated with 5’UTR length, explaining why eIF4A-dependent mRNAs have longer 5’UTRs. Crucially, in eIF4A-dependent mRNAs these highly-structured elements are located predominantly at the 3’ end of the 5’UTR, suggesting that increased structure just upstream of the CDS is most inhibitory to translation following eIF4A inhibition and is a key determinant of eIF4A-dependency.
2019-11-26 | GSE134865 | GEO
Project description:We have developed a deep sequencing-based approach, Rec-Seq, that allows simultaneous monitoring of ribosomal 48S pre-initiation complex (PIC) formation on every mRNA in the translatome in an in vitro reconstituted system. Rec-Seq isolates key early steps in translation initiation in the absence of all other cellular components and processes. Using this approach we show that the DEAD-box ATPase Ded1 promotes 48S PIC formation on the start codons of >1000 native mRNAs, most of which have long, structured 5’-untranslated regions (5’UTRs). Remarkably, initiation measured in Rec-Seq was enhanced by Ded1 for most mRNAs previously shown to be highly Ded1-dependent by ribosome profiling of ded1 mutants in vivo, demonstrating that the core translation functions of the factor are recapitulated in the purified system. Our data do not support a model in which Ded1acts by reducing initiation at start codons in 5’UTRs and instead indicate it functions by directly promoting mRNA recruitment to the 43S PIC and scanning to locate the start codon. We also provide evidence that eIF4A, another essential DEAD-box initiation factor, is required for efficient PIC assembly on almost all mRNAs, regardless of their structural complexity, in contrast to the preferential stimulation by Ded1 of initiation on mRNAs with long, structured 5’UTRs.
2023-10-03 | GSE244093 | GEO
Project description:DEAD-box RNA helicases eIF4A and Ded1 promote translation by resolving mRNA secondary structures that impede preinitiation complex (PIC) attachment to mRNA or scanning. eIF4B is a cofactor for eIF4A but might also function independently of eIF4A. Ribosome profiling of mutants lacking eIF4B or with impaired eIF4A or Ded1 activity revealed that eliminating eIF4B reduces the relative translational efficiencies of many more genes than does inactivation of eIF4A, despite comparable reductions in bulk translation, and few genes display unusually strong requirements for both factors. However, either eliminating eIF4B or inactivating eIF4A preferentially impacts mRNAs with longer, more structured 5’UTRs. These findings reveal an eIF4A-independent role for eIF4B in addition to its function as eIF4A cofactor in promoting PIC attachment or scanning on structured mRNAs. eIF4B, eIF4A, and Ded1 mutations also preferentially impair translation of longer mRNAs in a fashion mitigated by the ability to form closed-loop mRNPs via eIF4F-Pab1 association, suggesting cooperation between closed-loop assembly and eIF4B/helicase functions. Remarkably, depleting eIF4G, the scaffold subunit of eIF4F, preferentially impacts short mRNAs with strong closed-loop potential and unstructured 5’UTRs, exactly the opposite features associated with hyperdependence on the eIF4B/helicases. We propose that short, highly efficient mRNAs preferentially depend on the stimulatory effects of eIF4G-dependent closed-loop assembly.
2016-05-27 | GSE81966 | 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 use ribosome footprinting to assess the gene expression changes occuring after 10 minutes of heat stress at either 40°C or 42°C compared to non-stressed yeast cells (30°C). We find that between 40°C and 42°C there is a shift in gene expression from the expression of genes harboring long and structured 5'UTRs to the expression of genes harboring thranscripts with short and unstructure 5'UTRs. We performed these experiments for WT yeast cells as well as for mutant yeast cells in which the RNA helicase Ded1 condensates at lower temperatures (Ded1-IDRm). We find upon comparing mutant and WT cells at 42°C, that Ded1-IDRm has increased expression of genes harboring unstructured 5'UTRs and decreased expression of genes harboring structured 5'UTRs.
2020-04-30 | GSE131176 | GEO
Project description:CUG-binding protein 1 (CUGBP1) and muscleblind-like 1 (MBNL1) are developmentally regulated RNA-binding proteins that are causally associated with myotonic dystrophy type 1. We extensively determined RNA-binding sites of CUGBP1 and MBNL1 to investigate their roles in RNA processing. We also analyzed polypyrimidine tract-binding protein (PTB) as a control. CUGBP1 and MBNL1 preferentially bind to alternatively spliced introns and exons, respectively, and regulate alternative splicing events. Moreover, CUGBP1 and MBNL1 are preferentially bound to the 3' untranslated regions (UTRs), in particular of genes for RNA-binding proteins, and facilitate decay of the bound mRNAs. In addition, CUGBP1 and MBNL1 mutually destabilize mRNA. Precise temporal regulation of CUGBP1 and MBNL1 are likely to be essential for accurate control of destabilization of a broad spectrum of genes as well as of alternative splicing events in cell differentiation and tissue development.
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Project description:RNA helicases constitute a large protein family implicated in cellular RNA homeostasis and disease development. Here we show that the RNA helicase Ighmbp2, linked to the neuromuscular disorder SMARD1 (DSMA1) associates with polysomes and impacts on translation of cellular mRNAs containing short, GC-rich and highly structured 5’UTRs. Absence of Ighmbp2 causes ribosome stalling at the start codon of target mRNAs, leading to their reduced translation efficiency. The main mRNA targets of Ighmbp2-mediated regulation encode for components of the THO complex that links mRNA production and nuclear export. Accordingly, failure of Ighmbp2 regulation of the THO complex causes perturbations of the cellular transcriptome and its encoded proteome. Ablation of essential THO complex subunits phenocopies these perturbations. Thus, Ighmbp2 is an upstream regulator of the THO complex that impacts on cellular mRNA homeostasis. Of note, Ighmbp2 dependent regulation of the THO complex is also observed in astrocytes derived from DSMA1 patients, suggesting that de-regulated mRNA metabolism contributes to SMARD1 etiology.
2024-02-15 | PXD043336 | Pride
Project description:Rocaglamide A (RocA) typifies a class of protein synthesis inhibitors that selectively kill aneuploid tumor cells and repress translation of specific mRNAs. RocA targets eukaryotic initiation factor 4A (eIF4A), an ATP-dependent DEAD-box RNA helicase; its mRNA selectivity is proposed to reflect highly structured 5â² UTRs that depend strongly on eIF4A-mediated unwinding. However, rocaglate treatment may not phenocopy the loss of eIF4A activity, as these drugs actually increase the affinity between eIF4A and RNA. Here, we show that secondary structure in 5â² UTRs is only a minor determinant for RocA selectivity and RocA does not repress translation by reducing eIF4A availability. Rather, in vitro and in cells, RocA specifically clamps eIF4A onto polypurine sequences in an ATP-independent manner. This artificially clamped eIF4A blocks 43S scanning, leading to premature, upstream translation initiation and reducing protein expression from transcripts bearing the RocA-eIF4A target sequence. In elucidating the mechanism of selective translation repression by this lead anti-cancer compound, we provide an example of a drug stabilizing sequence-selective RNA-protein interactions. Bind-n-Seq and iCLIP-Seq
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Project description:The half-life of mRNAs, as well as their translation, increases proportionally to the optimal codons, indicating a tight coupling of codon-dependent differential translation and degradation. Little is known about the regulation of this coupling. We found that the coupling in yeast displays a dichotomous behavior regarding the mRNA coding sequence length. Below a critical length, codon optimality fails to affect the stability of mRNAs even though they can be efficiently translated into short peptides and proteins. Above this threshold length, codon optimality-dependent differential mRNA stability emerges in a switch-like fashion, which coincides with a similar increase in the polysome propensity of the mRNAs. This threshold length can be tuned by the untranslated regions (UTR). Some of these UTRs can destabilize mRNAs without reducing translation, which plays a role in controlling the amplitude of the oscillatory expression of cell-cycle genes. Our findings help understand the translation of short peptides from noncoding RNAs and the translation by localized monosomes in neurons.
2023-09-28 | GSE235627 | GEO
Project description:Nervous system (NS) development relies on coherent up-regulation of extensive sets of genes in a precise spatiotemporal manner. How such transcriptome-wide effects are orchestrated at the molecular level remains an open question. Here we show that 3’-untranslated regions (3’UTRs) of multiple neuronal transcripts contain A/U-rich cis-elements (AREs) recognized by tristetraprolin (TTP/Zfp36), an RNA-binding protein previously reported to destabilize mRNAs encoding predominantly cytokines, growth factors and proto-oncogenes. We further demonstrate that the efficiency of ARE-dependent mRNA degradation declines during neural differentiation due to a decrease in the TTP protein expression mediated by the NS-enriched microRNA miR-9. Our experiments with transgenenic cell lines suggest that TTP down-regulation is essential for proper neuronal differentiation. Moreover, inactivation of TTP in neuroblastoma cells or mouse embryonic fibroblasts induces major changes in their transcriptomes accompanied by significantly elevated expression of NS-specific genes. We conclude that the newly identified miR-9/TTP circuitry limits unscheduled accumulation of neuronal mRNAs in non-neuronal cells and ensures coordinated up-regulation of these transcripts in neurons. 3'READS of undifferentiated and 3.5-day differentiated P19 cells
2015-04-01 | E-GEOD-61098 | biostudies-arrayexpress