The Histone H3 (dimethylK79) antibody is a specialized tool used to detect the dimethylation of lysine 79 on histone H3 (H3K79me2), a post-translational modification implicated in chromatin regulation and epigenetic signaling. Histone H3 is a core component of nucleosomes, and its methylation at specific residues influences DNA accessibility, transcription, and genome stability. H3K79 methylation occurs within the globular domain of the histone, a region less commonly modified compared to the N-terminal tail. This modification is catalyzed by the methyltransferase DOT1L (Disruptor of Telomeric Silencing 1-like) in mammals, which exclusively targets H3K79 in a methylation gradient (mono-, di-, or trimethylation) depending on cell cycle phase and genomic context.
H3K79me2 plays roles in transcriptional elongation, DNA damage repair, and cell cycle regulation. It is enriched at actively transcribed gene bodies and interacts with proteins involved in chromatin remodeling and mRNA processing. Aberrant H3K79 methylation has been linked to leukemogenesis, particularly in mixed-lineage leukemia (MLL) rearrangements, where DOT1L activity is dysregulated. The Histone H3 (dimethylK79) antibody is widely used in chromatin immunoprecipitation (ChIP), immunofluorescence, and Western blotting to study its spatial and temporal distribution. Specificity validation via knockout/knockdown controls is critical, as cross-reactivity with other methylated histone residues or isoforms can occur. This antibody serves as a key reagent in epigenetics research, helping to unravel mechanisms of gene expression control and disease-associated chromatin states.