IκB kinase

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The IκB kinase (IKK) enzyme complex is part of the upstream NF-κB signal transduction cascade. The IκBα (inhibitor of kappa B) protein inactivates the NF-κB transcription factor by masking the nuclear localization signals (NLS) of NF-κB proteins and keep them sequestered in an inactive state in the cytoplasm. IKK specifically phosphorylates the inhibitory IκBα protein. This phosphorylation results in the dissociation of IκBα from NF-κB and thereby activates NF-κB.

Stucture

The IκB kinase complex is comprised of three subunits each encoded by a separate gene:

• IKKα (also known as IKK1) ()
• IKKβ (also known as IKK2) ()
• IKKγ (also known as NEMO) ()

The α- and β-subunits together are catalytically active whereas the γ-subunit serves a regulatory function.

References

External links

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Last updated on Sunday December 16, 2007 at 16:12:45 PST (GMT -0800)
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