Transcribing through the nucleosome

• Published in: Trends in biochemical sciences (Amsterdam. Regular ed.) Vol. 39; no. 12; pp. 577 - 586
• Main Authors: Teves, Sheila S., Weber, Christopher M., Henikoff, Steven
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.12.2014
• Subjects: Animals; Chromatin Assembly and Disassembly; DNA torsion; Eukaryota; Gene Expression Regulation; histone variants; Humans; Models, Biological; modifications; nucleosome barrier; Nucleosomes - metabolism; remodelers; RNA polymerase II; RNA Polymerase II - metabolism; Transcription, Genetic; histone variants; nucleosome barrier; DNA torsion; RNA polymerase II; remodelers; modifications
• ISSN: 0968-0004; 1362-4326
• DOI: 10.1016/j.tibs.2014.10.004

•Nucleosomes are non-uniform, context specific barriers that affect RNA Polymerase II (Pol II) transit.•Pol II transit affects stability and dynamics of transcribed nucleosomes.•Chromatin modifiers and histone variants modulate the barrier strength.•Transcription-generated torsional stress mediates nucleosome dynamics. The packaging of DNA into chromatin limits sequence accessibility, which affects all DNA-based processes including transcription. Indeed, the fundamental unit of chromatin, the nucleosome, presents a strong barrier to transcription in vitro. Since the discovery of the nucleosome barrier, the question of how the RNA polymerase II (Pol II) machinery overcomes nucleosomes at high speeds in vivo has remained a central question in chromatin biology. In this review, we discuss the nature of the nucleosomal barrier to transcription and highlight recent findings that provide new insights into the mechanism of transcription through nucleosomes.