The adjustable nucleosome: an epigenetic signaling module.

This review examines the proposition that the nucleosome, in addition to its role as a DNA packaging device, is a signaling module through which changing environmental and metabolic conditions can influence genomic functions. The role of enzyme-catalyzed post-translational modifications of the core histones is critically assessed, leading to the conclusion that they play varied, often crucial and sometimes causative roles in this signaling process.