The IKK complex:: an integrator of all signals that activate NF-κB?

The NF-kappa B family of transcription factors plays a crucial role in the immune, inflammatory and apoptotic responses. These proteins are normally found in the cytoplasm, retained by interaction with an inhibitory molecule called I kappa B. Activation of the NF-kappa B signalling cascade results in phosphorylation and degradation of I kappa B, allowing nuclear translocation of the NF-kappa B complexes. The recent identification of a high-molecular-weight complex containing two kinases and a regulatory subunit has led to a flurry of new results that shed light on some of the most complex mechanisms contributing to the exquisite regulation of NF-kappa B activity.