The Histone H3 is one of the five main histone proteins involved in the structure of chromatin in eukaryotic cells. Featuring a main globular domain and a long N-terminal tail, H3 is involved with the structure of the nucleosomes of the 'beads on a string' structure. The N-terminal tail of histone H3 protrudes from the globular nucleosome core and can undergo several different types of epigenetic modifications that influence cellular processes. These modifications include the covalent attachment of methyl or acetyl groups to lysine and arginine amino acids and the phosphorylation of serine or threonine. Arginine methylation of histones H3 (Arg2, 17, 26) and H4 (Arg3) promotes transcriptional activation and is mediated by a family of protein arginine methyltransferases (PRMTs), including the co-activators PRMT1 and CARM1 (PRMT4). In contrast, a more diverse set of histone lysine methyltransferases have been identified, all but one of which contain a conserved catalytic SET domain origin

Ki67 [EP5]

The antibody labels Ki-67, a proliferation-associated nuclear protein expressed during all active phases of the cell cycle. Quantitative determination of the fraction of cells which stain positive for the Ki-67 nuclear antigen has been demonstrated to be a highly accurate way of assessing the fraction of proliferating cells within a given tissue. Estimation of the cell proliferation index in tumor cells is valuable as a prognostic indicator.

Ki67 [EP5]