U-Blot® Histone H2B (Acetyl Lys20) 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 Lys20 acetylation (H2B K20ac) is deposited by p300/CBP at gene promoters and super-enhancers. It cooperates with other H2B acetylation marks to destabilize nucleosomes and enhance gene transcription. Tumor cells exhibit elevated H2B K20ac due to abnormally high p300 activity; HDAC inhibitors reduce this modification to suppress oncogenic transcription. It also participates in restoring normal transcriptional homeostasis after DNA damage repair.