Homo sapiens strain:HEK293
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA471492 | ENA |
REPOSITORIES: ENA
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Project description:The exon junction complex (EJC) deposited upstream of mRNA exon junctions shapes structure, composition and fate of spliced mRNA ribonucleoprotein particles (mRNPs). To achieve this, the EJC core nucleates assembly of a dynamic shell of peripheral proteins that function in diverse post-transcriptional processes. In this study we show that EJC exists in two mutually exclusive compositions characterized by peripheral proteins RNPS1 and CASC3. We identified transcriptome-wide binding sites of the two alternate EJCs via RNA:protein immunoprecipitation in tandem followed by deep sequencing (RIPiT-Seq). We show that RNPS1-EJC, which is an SR-rich mega-dalton sized RNP, is the major EJC form in the nucleus. After mRNP export to the cytoplasm and before translation, the EJC undergoes a remarkable compositional and structural remodeling into an SR- and RNPS1-devoid monomeric complex that contains CASC3. The CASC3-EJC is enriched on cytoplasmic RNAs and is the main EJC form that encounters ribosome and undergoes disassembly during translation.
2018-11-19 | GSE115977 | GEO
Project description:Alternative splicing of pre-mRNAs increases the potential for regulation and complexity of gene expression. The exon junction complex (EJC) and its associated splicing factor RNPS1 were recently shown to suppress mis-splicing resulting from the usage of cryptic and reconstituted 5’ and 3’ splice sites in the vicinity of the EJC. Here, we aimed to further investigate the mechanisms underlying splicing regulation by RNPS1. A transcriptome-wide analysis identified hundreds of splice events affected by the knockdown (KD) of RNPS1 in HeLa cells. These included alternative splice site usage as well as intron retention, exon skipping and inclusion. However, only a fraction of these RNPS1-dependent splice events was fully or partially rescued by the expression of the RNPS1 RRM. These results indicated that another domain of RNPS1 is involved in the regulation of the majority of splicing events. Deletion experiments revealed that the N-terminus and S-domain, and in particular the C-terminus of RNPS1 strongly regulate these events. Several splicing factors, including SR proteins and U1 snRNP components, were strongly reduced in the interactome of RNPS1 lacking the C terminus. We conclude that RNPS1 interacts with many splicing factors to direct the assembly of EJC-dependent and-independent splicing complexes.
2022-05-31 | PXD027251 | Pride
Project description:RNPS1 is a splicing regulatory protein and a component of the ASAP/PSAP complex, which is associated with the exon junction complex and modulates alternative splicing. It was previously postulated that the isolated RRM domain of RNPS1 in complex with ASAP/PSAP is able to regulate certain alternative splicing events. We aimed to investigate in HeLa Tet-Off cells which alternative splicing events are rescued by the expression of the isolated RRM domain of RNPS1 in a RNPS1 knockdown background by using RNA-Seq analyses. The rescue construct was stably integrated into the genome using the PiggyBac transposon system. As controls, either Luciferase (Luc) siRNA was used or RNPS1 was knocked down without rescue.
2022-05-06 | E-MTAB-10768 | biostudies-arrayexpress
Project description:RNPS1 is a splicing regulatory protein and a component of the ASAP/PSAP complex, which is associated with the exon junction complex and modulates alternative splicing. It was previously postulated that the isolated RRM domain of RNPS1 in complex with ASAP/PSAP is able to regulate certain alternative splicing events. We aimed to investigate in Flp-In T-REx 293 cells which alternative splicing events are rescued by the expression of the wild type RNPS1 or the isolated RRM domain of RNPS1 in a RNPS1 knockdown background by using RNA-Seq analyses. The rescue construct was stably integrated into the genome using the PiggyBac transposon system. As controls, either Luciferase (Luc) siRNA was used or RNPS1 was knocked down without rescue.
2022-05-06 | E-MTAB-10770 | biostudies-arrayexpress
Project description:The exon junction complex is deposited at 24nt upstream of exon-exon junctions, but not at every junction. The core complex is comprosed of 4 proteins, eIF4A3, Magoh, Y14 and MLN51. Here we performed immunoprecipitation of Y14 with subsequent iCLIP of eIF4A3 in HeLa cells to identify the crosslink sites of the exon junction complex, in particular eIF4A3.
2016-11-24 | E-MTAB-3618 | biostudies-arrayexpress
Project description:We report the knockdown and rescue of RNPS1, a component of the ASAP and PSAP complexes and, hence, an auxiliary component of the exon junction complex. The studied conditions show an extensive change in alternative splicing and the cell's transcriptome. For the knockdown, HeLa cells were transfected with siRNAs targeting RNPS1 or the Luciferase control. Total RNA was extracted with peqGOLD TriFast, underwent ribosomal depletion and strand-specific library preparation (TruSeq R Stranded Total RNA LT). Sequencing occurred in an Illumina HiSeq4000 sequencer with 2×75bp, producing roughly 35 million read-pair per sample.
2018-11-01 | E-MTAB-6564 | biostudies-arrayexpress
Project description:During gene expression, RNA export factors are mainly known for driving nucleocytoplasmic transport. While early studies suggested that the Exon Junction Complex (EJC) may provide a binding platform for them, subsequent work proposed that they are only recruited by the Cap-Binding Complex (CBC) to the 5’ end of RNAs, as part of the TREX complex. Using iCLIP, we show that the export receptor Nxf1 and two TREX subunits, Alyref and Chtop, are actually recruited to the whole mRNA co-transcriptionally via splicing but before 3’-end processing. Consequently, Alyref can alter splicing decisions and Chtop regulates alternative polyadenylation. Surprisingly, we observe that eIF4A3 stimulates Alyref deposition on single exon or spliced RNAs close to EJC sites. Additional experiments suggest that Alyref is recruited to the 5’-end of RNAs by CBC before binding RNAs near EJCs. Our study reveals mechanical insights into the co-transcriptional recruitment of mRNA export factors and how this shapes the human transcriptome.
2019-05-01 | GSE113952 | GEO
Project description:The exon junction complex (EJC) is a highly conserved ribonucleoprotein complex which binds RNAs during splicing and remains associated with them following export to the cytoplasm. While the role of this complex in mRNA localization, translation and degradation has been well characterized, its mechanism of action in splicing a subset of Drosophila and human transcripts remains to be elucidated. Here, we describe a novel function for the EJC and its splicing subunit RnpS1 in preventing transposon accumulation in both Drosophila germline and surrounding somatic follicle cells. This function is mediated specifically through the control of piwi transcript splicing, where in the absence of RnpS1 the fourth intron of piwi is retained. Within this intron the polypyrimidine tract is disrupted by a transposon-adjacent A/T-rich sequence that confers dependence on RnpS1. Finally, we demonstrate that RnpS1-dependent removal of this intron requires splicing of the flanking introns, suggesting a model in which the EJC facilitates the splicing of weak introns following its initial deposition at adjacent exon junctions. These data demonstrate a novel role for the EJC in regulating piwi intron excision and provide a mechanism for its function during splicing. Small-RNA libraries from two control samples and four knockdowns in germline or somatic tissues of the Drosophila melanogaster ovary.
2014-08-14 | E-GEOD-59327 | biostudies-arrayexpress
Project description:The exon junction complex (EJC) is a highly conserved ribonucleoprotein complex which binds RNAs at a late stage of the splicing reaction and remains associated following export to the cytoplasm. This complex is involved in several cellular post-transcriptional processes including mRNA localization, translation and degradation. The EJC plays an additional role in the splicing of a subset of genes in Drosophila and in human cells but the underlying mechanism remains to be elucidated. Here, we have found a novel function for the EJC and its splicing subunit RnpS1 in preventing transposon accumulation in both Drosophila germline and surrounding follicular cells. This function is mediated specifically through the control of the splicing of the piwi transcript. In absence of RnpS1 one of the piwi intron is retained. This intron contains a weak 5’ splice site as well as degenerate transposon fragments, reminiscent of heterochromatic introns. In addition, we identified a small A/T rich region, which alters its polypyrimidine tract (PPT) and confers the RnpS1’s dependency. Finally, we showed that the removal of this intron by RnpS1 requires the initial splicing of the flanking introns, suggesting a model in which the EJC facilitates the splicing of challenging introns following its initial deposition to adjacent exon junctions. In total there are 4 different conditions. Comparisons were made between piwi mutant vs control piwi and rnps1 KD vs controls RnpS1
2014-09-08 | E-GEOD-57710 | biostudies-arrayexpress
Project description:To uncover exon junction complex (EJC) deposition sites on cellular mRNAs, RNA footprints of EJC immuo-purified from HEK293 cells were deep sequenced. The analysis of these data revealed that major “canonical” EJC occupancy site in vivo lies 24 nucleotides upstream of exon junctions (-24 position) and that the majority of exon junctions carry an EJC. Unexpectedly, we find that many sites further upstream of -24 position are also enriched in these EJC footprints. These "non-canonical" sites are binding sites of EJC-interacting proteins with a subset being occupied by SR proteins. Thus, an EJC-SR protein nexus exists within spliced mRNPs and is revealed here.
2012-10-18 | GSE41154 | GEO