Anti-Histone H3.3 G34R from rabbit

Histone H3.3 (UniProt: P84243) is encoded by the H3FA3 (also known as H3.3A, H3F3, PP781, H3F3B, H3.3B) gene (Gene ID: 3020) in human. Histones are basic nuclear proteins that are responsible for the nucleosome structure of chromatin in eukaryotes. Two molecules of each of the four core histones (H2A, H2B, H3, and H4) form an octamer, around which DNA is wrapped in repeating units, called nucleosomes, which limits 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. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling. Histone H3.3 is expressed throughout the cell cycle independently of DNA synthesis. It is a variant histone H3 which replaces conventional H3 in a wide range of nucleosomes in active genes. It is the predominant form of histone H3 in non-dividing cells and is incorporated into chromatin independently of DNA synthesis. While H3.3 can function much the same as canonical H3 as a core part of the nucleosome, H3.3 is also deposited into transcriptionally active regions to replace displaced nucleosomes throughout the cell cycle. In tumor cells, H3.3K27M and H3.3G34R/V mutations are heterozygously expressed, with one allele of H3F3A being wildtype. K27M and G34R/V mutations are mutually exclusive in tumors and display distinct gene expression profiles and DNA methylation patterns. Almost all tumors bearing G34R/V mutations also exhibit mutations in ATRX/DAXX and display alternate lengthening of telomeres, which is a classical phenotype of cancerous cells. (Ref.: Yuen, BT., and Knoepfler PS (2013). Cancer cell 24(5); 567-74).