Regulation of alternative splicing via chromatin modifications

Alternative splicing (AS) is involved in expansion of transcriptome and proteome during cell growth, cell death, pluripotency, cell differentiation and development. There is increasing evidence to suggest that splicing decisions are made when the nascent RNA is still associated with chromatin. Here, I studied regulation of AS via chromatin modification with main focus on histone acetylation. First, we demonstrate that activity of histone deacetylases (HDACs) influences splice site selection in 700 genes. We provided evidence that HDAC inhibition induces histone H4 acetylation and increases RNA Polymerase II (RNA Pol II) processivity along an alternatively spliced element. In addition, HDAC inhibition reduces co-transcriptional association of the splicing regulator SRp40 with the target fibronectin exon. Further we showed that histone acetylation reader, Brd2 protein, affect transcription of 1450 genes. Besides, almost 290 genes change their AS pattern upon Brd2 depletion. We study distribution of Brd2 along the target and control genes and find that Brd2 is specifically localized at promoters of target genes only. Surprisingly, Brd2 interaction with chromatin cannot be explained solely by histone acetylation, which suggests that other protein-domains (in addition to bromodomains) are important for..