Project description:By targeted depletion of Cohesin (RAD21 subunit) or BRD4 alone or together, we have established that cohesin alone or with BRD4 regulates the alternative splicing of a large subset of genes under both physiological and heat shock conditions.
Project description:During heat stress cyto-protective genes including heat shock proteins are transcriptionally up-regulated and post-transcriptional splicing is inhibited. In contrast, co-transcriptional mRNA-splicing is maintained. These factors closely resemble the proteotoxic stress response during tumor development. The bromodomain protein BRD4 has been identified as an integral member of the oxidative stress as well as of the inflammatory response. Furthermore, there is evidence for BRD4's role in splicing regulation; Using RNA-Seq analyses we indeed found a significant increase in splicing inhibition, in particular intron retentions, during heat treatment in BRD4-deficient cells, but not under normal conditions. Subsequent experiments revealed that heat stress leads to the recruitment of BRD4 to nuclear stress bodies, to the interaction with the heat shock factor 1 (HSF1) and to the transcriptional up-regulation of non-coding Sat III RNA transcripts. These findings implicate BRD4 as a central regulator of splicing during heat stress. Since BRD4 is a potent target for anti-cancer therapies, our data linking BRD4 to the splicing machinery and the heat stress response - give additional insight into the mode of action of BRD4 inhibitors. WI38 cells have been treated by heatshock and anti BRD4 siRNA and combination.
Project description:We provide data showing alternative splicing regulation by Muscleblind proteins in MEFs. MEFs lacking functional Muscleblind (DKO MEFs) were stably reconstituted with Muscleblind proteins from Homo sapiens, Ciona intestinalis, Drosophila melanogaster, Caenorhabditis elegans or Trichoplax adhaerens and splicing regulation was explored using RNA-seq analysis followed by MISO (Mixture of Isoforms). Alternative splicing was accessed using RNA-sequencing data from five DKO MEF lines reconstituted with different GFP-tagged Muscleblind homologs or GFP alone and compared to RNA-seq data from three WT MEF lines and three control DKO MEFs (no Muscleblind reconstitution). A total of 12 samples were used for high-throughput sequencing.
Project description:During heat stress cyto-protective genes including heat shock proteins are transcriptionally up-regulated and post-transcriptional splicing is inhibited. In contrast, co-transcriptional mRNA-splicing is maintained. These factors closely resemble the proteotoxic stress response during tumor development. The bromodomain protein BRD4 has been identified as an integral member of the oxidative stress as well as of the inflammatory response. Furthermore, there is evidence for BRD4's role in splicing regulation; Using RNA-Seq analyses we indeed found a significant increase in splicing inhibition, in particular intron retentions, during heat treatment in BRD4-deficient cells, but not under normal conditions. Subsequent experiments revealed that heat stress leads to the recruitment of BRD4 to nuclear stress bodies, to the interaction with the heat shock factor 1 (HSF1) and to the transcriptional up-regulation of non-coding Sat III RNA transcripts. These findings implicate BRD4 as a central regulator of splicing during heat stress. Since BRD4 is a potent target for anti-cancer therapies, our data linking BRD4 to the splicing machinery and the heat stress response - give additional insight into the mode of action of BRD4 inhibitors.
Project description:Genome compartmentalization mediated by the cohesin complex plays an essential role in the maintenance of genome integrity and transcriptional regulation. Recurrent somatic mutations in multiple members of the cohesin complex are frequent genetic drivers in several types of cancer, including acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), but the cellular consequences of cohesin mutations have not been determined and no therapies have been identified with selective efficacy in cohesin-mutant cancers. Using quantitative proteomics and genome-wide genetic screens in genetically engineered models of STAG2-mutant AML, we identify changes in cohesin complex composition and dependency on STAG1, DNA damage repair, master transcription factors, and RNA splicing machinery. Consistent with these findings, loss of STAG2 leads to DNA replication fork stalling and is associated with increased levels of dsDNA breaks and activation of DNA damage checkpoints, as well as aberrant splicing. Genetic or pharmacologic perturbation of DNA damage repair or splicing creates a synthetic vulnerability for cohesin-mutant cells in vitro and in vivo. Finally, STAG2 loss leads to a global reduction in cohesin binding to chromatin and expansion of super-enhancers, and mutant cohesin complexes spatially co-localize with super-enhancer enriched factors, DNA damage and splicing machinery. Our findings inform the biology of cohesins in cancer cells, and highlight novel therapeutic possibilities for cohesin-mutant malignancies.
Project description:This SuperSeries is composed of the following subset Series: GSE23513: Position-dependent alternative splicing activity revealed by global profiling of alternative splicing events regulated by PTB (HJAY) GSE23514: Position-dependent alternative splicing activity revealed by global profiling of alternative splicing events regulated by PTB (Exon array) Refer to individual Series
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:Cohesin, a trimeric complex that establishes sister chromatid cohesion, has additional roles in chromatin organization and transcription. We report that among those roles is the regulation of alternative splicing through direct interactions and in situ colocalization with splicing factors. Degradation of cohesin results in marked changes in splicing, independent of its effects on transcription. Introduction of a single cohesin point mutation in embryonic stem cells alters splicing patterns, demonstrating causality. In primary human acute myeloid leukemia, mutations in cohesin are highly correlated with distinct patterns of alternative splicing. Cohesin also directly interacts with BRD4, another splicing regulator, to generate a pattern of splicing that is distinct from either factor alone, documenting their functional interaction. These findings identify a role for cohesin in regulating alternative splicing in both normal and leukemic cells and provide insights into the role of cohesin mutations in human disease.
Project description:We analyzed alternative splicing with Shh medulloblastoma. This dataset contains bam files of whole genome sequencing from 4 cases. Genomic DNA was isolated from both tumor and matched control specimens. We performed whole genome sequence on Illumina Hiseq.
Project description:Analysis to identify genome-wide differential alternative splicing events in A549 cells in which the levels of the gene SRSF1 were down-regulated with a specific siRNA 9 samples from three independent experiments using A549 cells transfected with lipofectamine alone, scramble siRNA or SRSF1 siRNA