Protein-Protein Interactions Involving IKKγ (NEMO) That Promote the Activation of NF-κB

Inhibitor of kappa B kinase (IKK) gamma (IKK-gamma), also referred to as nuclear factor kappa B (NF-kappa B) essential modulator (NEMO), is an important regulatory component of the IKK complex. The IKK complex is a signalosome that catalyzes the inducible phosphorylation of I kappa B proteins, which is a key step that leads to the activation of NF-kappa B. The exact functions of IKK-gamma (NEMO) as part of the IKK complex have not yet been fully elucidated. This mini-review covers 16 proteins that have been reported to bind to IKK gamma and lead to the enhancement of the activities of the IKK complex, thus resulting in NF-kappa B activation. The major mechanisms by which these interactions are mediated involve the recognition of ubiquitinated upstream signaling components by IKK gamma or the modification of IKK gamma itself by ubiquitination. Additional mechanisms include the sumoylation or phosphorylation of IKK-gamma and the modification of the tertiary or quaternary structure of IKK-gamma J. Cell. Physiol. 223: 558-561, 2010. (C) 2010 Wiley-Liss, Inc.