U-Blot® Histone H3.1 (Phospho Ser28) Rat mAb

Background: Histone H3 is one of the core components of the nucleosome. The nucleosome is the smallest subunit of chromatin and consists of 147 base pairs of DNA wrapped around an octamer of core histone proteins (two each of Histone H2A, Histone H2B, Histone H3 and Histone H4). Chromatin is subject to a variety of chemical modifications, including post-translational modifications of the histone proteins and the methylation of cytosine residues in the DNA. Reported histone modifications include acetylation, methylation, phosphorylation, ubiquitylation, glycosylation, ADP-ribosylation, carbonylation and SUMOylation; these modifications play a major role in regulating gene expression. There are three protein variants of Histone H3, Histone H3.1, 3.2 and 3.3. The incorporation of Histone H3.1 and H3.2 into nucleosomes is replication dependent, in contrast to Histone H3.3, which is independent of DNA synthesis and occurs throughout the cell cycle. Human Histone H3.1 and H3.3 are identical in amino acid sequences except at position 110 where H3.1 has a cysteine and H3.3 has a serine. Phosphorylation of serine 28 occurs in early mitosis when chromosomes begin to condense and during premature chromosome condensation induced in S-phase cells.