Background
Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. Ubiquitination, a post-translational modification in which the ubiquitin is covalently attached to a substrate protein, occurs on histones H2A and H2B. Histone H2A is mono-ubiquitinated at Lys119 by the Polycomb Repressor Complex 1 (PRC1) and is critical for gene silencing, X chromosome inactivation, and cellular response to DNA damage. Histone H2A is also monoubiquitinated at Lys119 at sites of DNA damage.
Cellular location
Nucleus
