A Nucleosome Destabilizing Factor that Facilitates Transcription in Chromatin

Our understanding of transcription by RNA polymerase II (Pol II) is limited by our knowledge of the factors that mediate this critically important process. Here we describe the identification of NDF, a nucleosome destabilizing factor that facilitates Pol II transcription in chromatin. NDF has a PWWP motif, interacts with nucleosomes near the dyad, partially disassembles nucleosomes in an ATP-independent manner, and enhances transcription by Pol II through nucleosomes in vitro and in cell nuclei. NDF affects gene expression and co-localizes with H3K36me3 over transcribed regions of a subset of active genes with a preference for longer genes relative to shorter genes. Moreover, induction of transcription leads to the recruitment of NDF over gene bodies. In humans, NDF is present in all tested tissue types, is essential in stem cells, and is frequently overexpressed in breast cancer. Thus, NDF is a factor of primary importance for Pol II transcription in chromatin.