Project description:Mitochondria are the central hub of energy and metabolism of the cell,acting as one of the most important organelles of living cells.Under mitochondrial stresses, cells will trigger mitochondrial unfolded protein response (UPRmt) to maintain mitochondrial homeostasis.We have verified that splicing facotrs are required for the activation of UPRmt.Knocking down of splicing fator prp-19 could supresse UPRmt activation.We analysis the differencial alternative splicing of worms on L4440 RNAi or prp-19 RNAi and untreated or treated with atp-2 RNAi, we found that inhibition of prp-19 interrupts splicing homeostasis of c.elegans.
Project description:This SuperSeries is composed of the following subset Series: GSE30995: An Alternative Splicing Switch Regulates Embryonic Stem Cell Pluripotency and Reprogramming [RNA-Seq] GSE31006: An Alternative Splicing Switch Regulates Embryonic Stem Cell Pluripotency and Reprogramming [ChIP-Seq] GSE31007: An Alternative Splicing Switch Regulates Embryonic Stem Cell Pluripotency and Reprogramming [protein binding microarray] GSE31948: An Alternative Splicing Switch Regulates Embryonic Stem Cell Pluripotency and Reprogramming [AS microarray] Refer to individual Series
Project description:Mediator complex is an integrative hub for transcriptional regulation. Here we show that Mediator regulates alternative mRNA processing via its Med23 subunit. Combining tandem affinity purification and mass spectrometry, we identified a number of mRNA processing factors that bind to a soluble recombinant Mediator subunit MED23 but not to several other Mediator components. One of these factors, hnRNP L, specifically interacts with MED23 in vitro and in vivo. Consistently, Mediator partially colocalizes with hnRNP L and the splicing machinery in the cell. Functionally Med23 regulates a subset of hnRNP L-targeted alternative splicing (AS) and alternative cleavage and polyadenylation (APA) events as shown by minigene reporters and exon array analysis. ChIP-seq analysis revealed that Med23 can regulate hnRNP L occupancy at their co-regulated genes. Taken together, these results demonstrate a crosstalk between Mediator and the splicing machinery, suggesting a novel mechanism for coupling mRNA processing to transcription. Examination of hnRNP L and H3K36me3 enrichment in sictrl and si23 Hela cells
Project description:Complex functional coupling exists between transcriptional elongation and pre-mRNA alternative splicing. Pausing sites and changes in the rate of transcription by RNAPII may therefore have a fundamental impact in the regulation of alternative splicing. Here, we show that the elongation and splicing-related factor TCERG1 regulates alternative splicing of the apoptosis gene Bcl-x in a promoter-dependent manner. TCERG1 promotes the splicing of the short isoform of Bcl-x (Bcl-xs) through the SB1 regulatory element located in the first half of exon 2. Consistent with these results, we show evidence for in vitro and in vivo interaction of TCERG1 with the Bcl-x pre-mRNA. Transcription profile analysis reveals that the RNA sequences required for the effect of TCERG1 on Bcl-x alternative splicing coincide with a putative polymerase pause site. Furthermore, TCERG1 modifies the impact of a slow polymerase on Bcl-x alternative splicing. In support of a role for an elongation mechanism in the transcriptional control of Bcl-x alternative splicing, we found that TCERG1 modifies the amount of pre-mRNAs generated at distal regions of the endogenous Bcl-x. Most importantly, TCERG1 affects the rate of RNAPII transcription of endogenous human Bcl-x. We propose that TCERG1 modulates the elongation rate of RNAPII to relieve pausing, thereby activating the pro-apoptotic Bcl-xS 5’ splice site. ChIP-Seq
Project description:CRKL adaptor protein was demonstrated to have important effects in various types of human cancer and contributes to malignant cell growth and chemoresistance as an overexpressed oncoprotein in cervical carcinoma. But the special molecular mechanisms of CRKL in cervical cancer remain unknown. Here we reported that CRKL regulates genes in cervical cancer related pathways via targeting alternative splicing. We analyzed the expression level of CRKL in 300 cervical cancer tissue samples available in TCGA database, showing a significant increase expression in Stage I cancer samples. From these tumor samples, we selected 40 cancer samples with 20 showing high CRKL expression and 20 showing low, which were analyzed for the potential impact of CRKL on alternative splicing regulation of cancer transcriptome. We further explored the potential function of CRKL in promoting cell proliferation and regulating alternative splicing in HeLa cells using shRNA to knock-down CRKL expression. More importantly, we showed that 34 (94%) of CRKL-regulated alternative splicing events detected in HeLa cells could be validated by qPCR approach and more than a half of these validated events detected in HeLa cells were also correlated with the CRKL expression level in cervical cancers. These results together support a conclusion that CRKL adaptor protein extensively regulates alternative splicing of many genes which are important in tumorigenesis and cancer progression, which expands the functional importance of signaling adaptors in coordinating the dynamic activation of signaling pathways with cellular responses at the alternative splicing level.
Project description:The conserved ubiquitin-like protein Hub1/UBL-5 associates with proteins non-covalently. In yeast and human cells, Hub1 promotes splicing of precursor mRNAs with weak introns and alternative splicing, however, its splicing function has remained elusive in multicellular organisms. We demonstrate the splicing function of Hub1/UBL-5 in the free-living nematode Caenorhabditis elegans. UBL-5 binds to the HIND-containing splicing factors Snu66/SART-1 and PRP-38 and associates with other spliceosomal proteins. Caenorhabditis elegans hub1/ubl-5 mutants die at the larval L3 stage, and show accumulation of intron- and outron-containing transcripts. The latter observation adds to UBL-5’s splicing function in trans-RNA splicing. UBL-5 complements splicing defects of hub1-knockout Schizosaccharomyces pombe, confirming its functional conservation. Thus, UBL-5 is important for C. elegans development and cis- and trans-RNA splicing.