Histone proteins, the primary protein component of chromatin, are known to be modified by O-GlcNAc. O-GlcNAc has been identified on all core histones (H2A, H2B, H3, and H4). The presence of O-GlcNAc on histones has been suggested to affect gene transcription as well as other histone marks such as acetylation and monoubiquitination. TET2 has been reported to interact with the TPR domain of OGT and facilitate recruitment of OGT to histones. This interaction is associated with H2B S112 O-GlcNAc, which in turn is associated with H2B K120 monoubiquitination. Phosphorylation of OGT T444 via AMPK has been found to inhibit OGT-chromatin association and downregulate H2B S112 O-GlcNAc.