Background NF-kB is silenced in the cytoplasm by an inhibitory protein, IkB (1). Synthesis of IkBa is autoregulated (2). IkB proteins are phosphorylated by IkB kinase complex consisting of at least three proteins, IKK1/a, IKK2/b, and IKK3/g (3-6). External stimuli such as tumor necrosis factor or other cytokines results in phosphorylation and degradation of IkB releasing NF-kB dimers. NF-kB dimer subsequently translocates to the nucleus and activates target genes. Six members of IkB family members have been identified (1). One of the first gene induced following NF-kB activation is IkBa. |
Reference
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