Project description:We used RNA sequencing to identify the RBFOX1 splicing network at a genome-wide level in primary human neural stem cells during differentiation. We observe that RBFOX1 regulates a large set of alternative splicing events implicated in neurogenesis and cell maintenance. Subsequent alterations in gene expression define an additional transcriptional network regulated by RBFOX1 involved in neurodevelopmental pathways remarkably parallel to those affected by splicing.
Project description:TCERG1 is a highly conserved human protein implicated in interactions with the transcriptional and splicing machinery. To investigate TCERG1 function, we survey genome-wide changes in transcript and exon levels upon TCERG1 knockdown in HEK293T cells. Our data revealed that TCERG1 regulates different types of alternative spliced events, indicating a broad role in the regulation of alternative splicing.
Project description:Epithelial specific splicing regulatory protein 1 and 2 (ESRP1 and ESRP2) are important regulators of alternative splicing during EMT. To study the alternative splicing events regulated by ESRP1/2 at a genome wide scale, we used lentiviral shRNAs to knockdown ESRP1/2 in H358 cells and performed RNA-seq in biological triplicates.
Project description:We used RNA sequencing to identify the RBFOX1 splicing network at a genome-wide level in primary human neural stem cells during differentiation. We observe that RBFOX1 regulates a large set of alternative splicing events implicated in neurogenesis and cell maintenance. Subsequent alterations in gene expression define an additional transcriptional network regulated by RBFOX1 involved in neurodevelopmental pathways remarkably parallel to those affected by splicing. RNA sequencing at a 75bp single-end read scale was performed using polyA-enriched RNA from 5 biological replicates of primary human neural progenitor cell lines generated by lentiviral-mediated knockdown of GFP (control) or RBFOX1 and differentiated for 4 weeks.
Project description:Alternative polyadenylation has been implicated as an important regulator of gene expression. In some cases, alternative polyadenylation is known to couple with alternative splicing to influence last intron removal. However, it is unknown whether alternative polyadenylation events influence alternative splicing decisions at upstream exons. Knockdown of the polyadenylation factors CFIm25 or CstF64 was used as an approach in identifying alternative polyadenylation and alternative splicing events on a genome-wide scale. Although hundreds of alternative splicing events were found to be differentially spliced in the knockdown of CstF64, genes associated with alternative polyadenylation did not exhibit an increased incidence of alternative splicing. These results demonstrate that the coupling between alternative polyadenylation and alternative splicing is usually limited to defining the last exon. The striking influence of CstF64 knockdown on alternative splicing can be explained through its effects on UTR selection of known splicing regulators such as hnRNP A2/B1, thereby indirectly influencing splice site selection. We conclude that changes in the expression of the polyadenylation factor CstF64 influences alternative splicing through indirect effects. HeLa cell line was stably transfected with shRNA plasmids targeting CstF64. Total RNA was isolated from CstF64 KD cells and wild-type control cells using Trizol according to manufacturerâs protocols. Samples were deep sequenced in duplicate using the Illumina GAIIx system.
Project description:Cancer cells experiencing hypoxic stress employ epithelial-mesenchymal transition (EMT) to undergo metastasis through rewiring of the chromatin landscape, epigenetics and importantly alternative splicing. However, how hypoxia influences expression and genome-wide redistribution of CTCF is still not known. Here, we performed CTCF-ChIP-seq and CUT&RUN assay to analyze differential occupancy of CTCF in normoxic and hypoxic breast cancer cell line. We discovered that hypoxia-induced gain of CTCF occupancy across the genome regulates EMT in hypoxic cells. Specifically, we did 4C-seq experiments on COL5A1 (EMT associated gene) gene loci and showed that CTCF-mediated promoter-exon upstream looping regulates epigenetic mark mainly DNA demethylation at distal alternatively spliced exon 64 and regulates CTCF-mediated RNA Pol II pausing at COL5A1exon64A that decides the outcome of splicing to favor EMT under hypoxia. Overall, we uncover that hypoxia-induced differential CTCF occupancy across the genome is associated with gene expression and alternative splicing events related to cancer progression, similarly to the proposed model.
Project description:Genome wide expression profiling to determine the overlap of Affymetrix-signals with SOLID sequencing RNA was extracted using the Qiagen RNeasy kit following the manufacturers guidelines, arrays were prepared and hybridized following the Affymetrix protocol.
Project description:Alternative splicing generates functional diversity in higher organisms through alternative first and last exons, skipped and included exons, intron retentions and alternative donor and acceptor sites. In large-scale microarray studies in human and mouse, emphasis so far has been placed on exon-skip events, leaving the prevalence and importance of other splice types largely unexplored. Using a new human splice variant database and a genome-wide microarray to probes thousands of splice events of each type, we measured differential expression of splice types across 6 pairs of diverse cell lines and validated the database annotation process. Results suggest that splicing in human is more complex than simple exon skip events, which account for a minority of splicing differences. The relative frequency of differential expression of the splice types correlates with what is found by our annotation efforts. In conclusion, alternative splicing in human cells is considerably more complex than the canonical example of the exon-skip. The complementary approaches of genome-wide annotation of alternative splicing in human and design of genome-wide splicing microarrays to measure differential splicing in biological samples provide a powerful high-throughput tool to study the role of alternative splicing in human biology. Keywords: alternative splicing