HMGB1 belongs to high mobility group and contains HMG-box domain. Like the histones, HMGB1 is among the most important chromatin proteins. The presence of HMGB1 in the nucleus depends on posttranslational modifications. When the protein is not acetylated, it stays in the nucleus, but hyperacetylation on lysine residues causes it to translocate into the cytosol. HMGB1 is an intracellular protein that can translocate to the nucleus where it binds DNA and regulates gene expression. HMGB1 can interact with TLR ligands and cytokines, and activates cells through the multiple surface receptors including TLR2, TLR4, and RAGE. HMGB1 has been proposed as a target for cancer therapy.
