Project description:We isolated snRNP complexes derived from precatalytic A or B-like spliceosomes solubilized from the chromatin pellet of lysed nuclei. These complexes contained U2 snRNP proteins and a portion of the U2 snRNA, bound with intronic branch sites prior to the first catalytic step of splicing. The complexes have similar composition, whether directly isolated from extracted material, or after selection from glycerol gradients. Here we describe sequencing libraries prepared from RNA derived from directly isolated (IP-seq), or gradient-purified complexes (RNP-seq). Libraries from deproteinized RNA were prepared after selective degradation of U2 snRNA, each in a triplicate. An additional library from RBM5-Flag RNP complex was prepared without such degradation. The majority of sequenced pre-mRNA fragments map to intronic branch sites.
Project description:While Argonaute (AGO) proteins play a major role in transcriptional gene silencing (TGS) in many organisms, their role in the nucleus of somatic mammalian cells remains elusive. Here, we have purified AGO1 and AGO2 chromatin-embedded complexes, and found these proteins associated with previously described partners, but also with chromatin modifiers and, rather unexpectedly, with different splicing factors. Using the CD44 gene as a model for alternative splicing, we show that both AGO1 and AGO2 are required for Protein Kinase C (PKC)-dependent variant exon inclusion. AGO proteins facilitate the spliceosome recruitment and modulate the elongation rate of RNA polymerase II (RNAPII). The recruitment of AGO proteins to CD44 transcribed region is dependent on both the endonuclease Dicer and the chromodomain-containing protein HP1g, and results in locally increased levels of histone H3 lysine 9 (H3K9) methylation on variant exons. Genome wide analysis of splicing in either AGO2 or Dicer null cells showed that the two proteins have similar effects on many splicing events. Finally, sRNAs associated with nuclear AGO2 are mostly in sense orientation relative to protein-coding genes, supporting a role for intragenic antisense non-coding RNAs in the recruitment AGO and splicing factors. Together, our data demonstrate for the first time that the endogenous RNAi pathway is involved in alternative splicing decisions, unravelling a new model in which AGO proteins couple RNAPII elongation and chromatin modification. Deep sequencing of small RNAs (approx. 15-80 nucleotides) bound to either cytoplasmic or chromatin-associated AGO2 complex.
Project description:The heterogeneous collection of NuRD complexes can be grouped into the MBD2 or MBD3 containing complexes MBD2-NuRD and MBD3-NuRD. Although functional differences have been described, a direct comparison of MBD2 and MBD3 in respect to genome-wide binding and function has been lacking. Here we show a strong enrichment for MBD2 at methylated CpG sequences, whereas CpGs bound by MBD3 are devoid of methylation. Gene activity of MBD2 bound genes is four fold lower as compared to genes bound by MBD3. When depleting cells for MBD2, the MBD2 bound genes increase their activity, whereas MBD2 plus MBD3 bound genes reduce their activity. Most strikingly, MBD3 is enriched at active promoters, whereas MBD2 is bound at methylated promoters and enriched at exon sequences of active genes. This suggests a functional connection between MBD2 binding to chromatin and splicing. V5 ChIP followed by high throughput sequencing in HeLa cells transiently transfected with either V5-MBD2b, V5-MBD3 or V5.
Project description:Transcriptional profiling of WT and myd88-/- macrophages infected with WT and hly- L. monocytogenes for 30, 60, 120, or 180 minutes Keywords: Timecourse, cell type comparison, bacteria strain comparison.
Project description:Assess chromatin accessibility in WT and mutant ES E14 strains using ATAC-seq. Mutant strains are depleted for subunits of the coactivator complexes SAGA (Supt7l KO) or ATAC (Yeats2, Zzz3) using constitutive knock-out (KO) or the auxin-inducible degron (AID) system.
Project description:The heterogeneous collection of NuRD complexes can be grouped into the MBD2 or MBD3 containing complexes MBD2-NuRD and MBD3-NuRD. Although functional differences have been described, a direct comparison of MBD2 and MBD3 in respect to genome-wide binding and function has been lacking. Here we show a strong enrichment for MBD2 at methylated CpG sequences, whereas CpGs bound by MBD3 are devoid of methylation. Gene activity of MBD2 bound genes is four fold lower as compared to genes bound by MBD3. When depleting cells for MBD2, the MBD2 bound genes increase their activity, whereas MBD2 plus MBD3 bound genes reduce their activity. Most strikingly, MBD3 is enriched at active promoters, whereas MBD2 is bound at methylated promoters and enriched at exon sequences of active genes. This suggests a functional connection between MBD2 binding to chromatin and splicing.
Project description:The heterogeneous collection of NuRD complexes can be grouped into the MBD2 or MBD3 containing complexes MBD2-NuRD and MBD3-NuRD. MBD2 is known to bind to methylated CpG sequences in vitro in contrast to MBD3. Although functional differences have been described, a direct comparison of MBD2 and MBD3 in respect to genome-wide binding and function has been lacking. Here we show when depleting cells for MBD2, the MBD2 bound genes increase their activity, whereas MBD2 plus MBD3 bound genes reduce their activity. Most strikingly, MBD3 is enriched at active promoters, whereas MBD2 is bound at methylated promoters and enriched at exon sequences of active genes. This suggests a functional connection between MBD2 binding to chromatin and splicing.
Project description:Transcriptional profiling of WT and irf3-/- macrophages infected with WT L. monocytogenes for 180 minutes Keywords: Cell type comparison.