OGT Protein, Human (His)

OGT is an enzyme that catalyzes the transfer of a single N-acetylglucosamine from UDP-GlcNAc to serine or threonine residues in cytoplasmic and nuclear proteins, modifying them with a beta-linked N-acetylglucosamine (O-GlcNAc). It glycosylates a wide range of proteins, including histone H2B, AKT1, AMPK, ATG4B, CAPRIN1, EZH2, and others, regulating their cellular functions through crosstalk between glycosylation and phosphorylation or by affecting proteolytic processing. In muscle and adipocyte cells, OGT contributes to insulin resistance by glycosylating insulin signaling components and inhibiting AKT1 phosphorylation at 'Thr-308' (by similarity). Additionally, OGT regulates glycolysis by mediating the glycosylation of 6-phosphofructokinase PFKL, thereby inhibiting its activity. In chromatin structure, OGT plays a crucial role by mediating O-GlcNAcylation of histone H2B at 'Ser-112' and is recruited to CpG-rich transcription start sites of active genes via interaction with TET proteins (TET1, TET2, or TET3). The mitochondrial isoform (mOGT) exhibits cytotoxicity and induces apoptosis in various cell types, including the insulinoma cell line INS1.