U-Blot® Histone H2B (Acetyl Lys23) Rabbit mAb

Background: Canonical histone H2B heterodimerizes with H2A to assemble the core nucleosome particle. Reversible lysine acetylation on the flexible N-terminal tail of H2B is a classic marker of transcription-permissive chromatin. Acetylation neutralizes positive charges of histone tails, weakens histone-DNA interaction and creates binding sites for bromodomain-containing co-activators. Different lysine sites on H2B tail carry distinct functions in transcription initiation, elongation and post-damage chromatin recovery. H2B Lys23 acetylation (H2B K23ac) is catalyzed by p300/CBP and TIP60, marking housekeeping gene promoters and signal-inducible enhancers. N-terminal multi-acetylation of H2B including K23ac serves as a reliable genome-wide marker for functional enhancers. During cellular senescence and terminal differentiation, H2B K23ac declines to maintain stable repressive chromatin; transient upregulation occurs after DNA repair to recover transcriptional activity.