Histone H3 (acetyl K4) Recombinant Rabbit mAb (S-4365)

Histone H3 lysine 4 acetylation (H3K4ac) is a crucial epigenetic modification. It specifically refers to the acetylation of the lysine residue at the fourth position (K4) on the N-terminal tail of histone H3. This modification is primarily catalyzed by histone acetyltransferases (HATs), such as p300/CBP, and can be removed by histone deacetylases (HDACs). Functionally, H3K4ac is strongly associated with transcriptional activation. It is typically enriched at active regulatory regions, including gene promoters and enhancers. By neutralizing the positive charge on the lysine, H3K4ac weakens the interaction between histones and the negatively charged DNA, leading to a more open chromatin structure. This relaxed state facilitates the binding of transcription factors and RNA polymerase II, thereby promoting gene expression. H3K4ac often functions cooperatively with other activating marks (e.g., H3K27ac) and serves as a key signature for defining active promoters and enhancers, playing a central regulatory role in processes such as cell differentiation, development, and disease pathogenesis.