TANK Binding Kinase 1 (TBK1)

The NF-kappa-B (NFKB) complex of proteins is inhibited by I-kappa-B (IKB) proteins, which inactivate NFKB by trapping it in the cytoplasm. TANK-Binding Kinase 1 is similar to IKB kinases and can mediate NFKB activation in response to certain growth factors. For example, the protein can form a complex with the IKB protein TANK and TRAF2 and release the NFKB inhibition caused by TANK.The cDNA encodes a deduced 730-amino acid protein that contains a leucine zipper and a helix-loop-helix motif within its C-terminal half. Unlike IKBKA and IKBKB, which each contain 2 serines in their respective activation loops, NAK contains a glutamic acid (glu168) and a serine, which must be phosphorylated for activation. Northern blot analysis revealed ubiquitous expression of a 2.2-kb transcript, with highest expression in testis.