NF-κB is silenced in the cytoplasm by an inhibitory protein IκB.1 Synthesis of IκBα is autoregulated.2 IκB proteins are phosphorylated by IκB kinase complex consisting of at least three proteins, IKK1/α, IKK2/β, and IKK3/γ.3,4,5,6 External stimuli such as tumor necrosis factor or other cytokines initiates a signal transduction cascade that leads to activation of the IκB-kinase complex that specifically phosphorylates IκBa on serine32 and serine36. Phosphorylation of these sites leads to ubiquitination of IκBα and subsequent degradation by the 26S proteasome. Degradation of IκBα results in unmasking of the nuclear localization signal of NF-κB dimers, which subsequently translocate to the nucleus and activate target genes.7,8 Six members of the IκB family members have been identified.1 one of the first genes induced following NF-κB activation is IκBα.WARNING This product is not for human or veterinary use.
