| description |
The protein Vezf1 plays multiple roles important for embryonic development. In Vezf1-/- mouse embryonic stem (MES) cells our earlier data showed widespread changes in gene expression profiles, including decreased expression of the full length active isoform of Dnmt3b methyltransferase and concomitant genome wide reduction in DNA methylation. Here we show that, in HeLaS3 cells, there is a strong genome-wide correlation between Vezf1 binding and peaks of elongating Ser2-P Pol ll, reflecting Vezf1 dependent slowing of elongation. In Wt MES cells the elongating form of RNA polymerase II accumulates near Vezf1 binding sites within the dnmt3b gene and at several other Vezf1 sites, and this accumulation is significantly reduced at these sites in Vezf1-/- MES cells. Depending upon genomic location, Vezf1 mediated Pol II pausing can have different regulatory roles in transcription and splicing. We find examples of genes in which Vezf1 binding sites are located near cassette exons, and in which loss of Vezf1 leads to a change in the relative abundance of alternatively spliced messages. We further show that Vezf1 interacts with Mrg15/Mrgbp, a protein that recognizes H3K36 tri-methylation, consistent with the role of histone modifications at alternatively spliced sites.Overall design: Comparison of Vezf1 and RNA Pol II binding in mouse and human cells. |