RNA polymerase II elongation through chromatin
Eukaryotic DNA is organized into structural units called nucleosomes which are comprised of DNA wrapped around histone proteins. Histones are the main protein components of chromatin and not only coordinate DNA packaging, but also play a vital role in gene regulation. RNA polymerase II (Pol II) and pre-initiation complex (PIC) transcription factors bind gene promoters, which are typically devoid of nucleosomes. Once transcription is initiated, Pol II along with DSIF and other elongation factors must navigate through nucleosomes to transcribe DNA into pre-mRNA. The mechanistic details of how transcription elongation is regulated through nucleosomes remains poorly understood. Using a reconstituted in vitro transcription system, I am studying the mechanisms by which different factors contribute to elongation of pre-mRNA transcripts through nucleosomal arrays. Results from these experiments will be probed further in cells.