Histone H2B (Ser-36), Phosphospecific Antibody

The nucleosome is a protein complex consisting of four core histones (H2A, H2B, H3, and H4) . Two molecules of each histone forms an octamer that makes up the nucleosome. DNA wraps around repeating nucleosome units to generate chromatin structures. The structure of chromatin determines the accessiblity to transcription factors. Post-translational modification of the amino-terminal tail of histones in nucleosomes alters chromatin structure to promote or inhibit transcription. Complex alterations in acetylation, methylation, ubiquination, and/or phosphorylation determine the chromatin structural changes that occur during specific phases of the cell cycle or in response to cell stimuli. One mode of regulating histone H2B activity is through phosphorylation in the amino terminal region. Important sites of phosphorylation include Ser-14, Ser-32, and Ser-36. AMPK phosphorylates Ser-36 on histone H2B during cell stress leading to increased transcription and cell survival, while ectopic expression of an unphosphorylatable histone H2B during cell stress reduces transcription of AMPK-dependent genes and lowers cell survival.

The antibody detects a 15 kDa* protein corresponding to the molecular mass of Histone H2B on SDS-PAGE immunoblots of human Jurkat cells treated with Calyculin A, and this reactivity is reduced after lambda phosphatase treatment. This sequence is well conserved in most isoforms of rat and mouse histone H2B, and has low homology to other histone family members.