title: Pre-mRNA splicing is a determinant of nucleosome organization.
abstract: Chromatin organization affects alternative splicing and previous studies have shown that exons have increased nucleosome occupancy compared with their flanking introns. To determine whether alternative splicing affects chromatin organization we developed a system in which the alternative splicing pattern switched from inclusion to skipping as a function of time. Changes in nucleosome occupancy were correlated with the change in the splicing pattern. Surprisingly, strengthening of the 5' splice site or strengthening the base pairing of U1 snRNA with an internal exon abrogated the skipping of the internal exons and also affected chromatin organization. Over-expression of splicing regulatory proteins also affected the splicing pattern and changed nucleosome occupancy. A specific splicing inhibitor was used to show that splicing impacts nucleosome organization endogenously. The effect of splicing on the chromatin required a functional U1 snRNA base pairing with the 5' splice site, but U1 pairing was not essential for U1 snRNA enhancement of transcription. Overall, these results suggest that splicing can affect chromatin organization.
authors: Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors: Hadas
authors: H
authors: Keren-Shaul
authors: Galit
authors: G
authors: Lev-Maor
authors: Gil
authors: G
authors: Ast
mesh_terms: D017398:Alternative Splicing / Q000235:genetics*; D057809:HEK293 Cells; D006801:Humans; D009707:Nucleosomes / Q000235:genetics*; D012319:RNA Polymerase II / Q000378:metabolism; D012322:RNA Precursors / Q000235:genetics*
chemical_list: D009707:Nucleosomes; D012322:RNA Precursors; D012319:RNA Polymerase II