NF-κB activation:: nondegradative ubiquitination implicates NEMO

Non-degradative ubiquitination events have been recently demonstrated to have an important role in activating the I kappa B kinase (IKK) complex, the central component of the nuclear factor (NF)-kappa B signaling cascade. Two new papers demonstrate that NF-kappa B essential modulator (NEMO)-IKK gamma, the structural and regulatory component of the IKK complex, specifically recognizes Lys63 polyubiquitin chains attached to the receptor-interacting protein (RIP)1 kinase following tumor necrosis factor treatment, and that this recognition is a requirement for IKK activation.