Role of Unphosphorylated, Newly Synthesized IκBβ in Persistent Activation of NF-κB
Molecular and Cellular BiologyPublished 1 October 1996Open access
Helena Suyang, Roderick J. Phillips, Iris Douglas, Sankar Ghosh
Citations218
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TL;DR
It appears that during prolonged stimulation, I kappa B beta functions as a chaperone for NF-kappa B by protecting it from I k Kappa B alpha and allowing it to be transported to the nucleus.
Abstract
Stimulation with inducers that cause persistent activation of NF-kappa B results in the degradation of the NF-kappa B inhibitors, I kappa B alpha and I kappa B beta. Despite the rapid resynthesis and accumulation of I kappa B alpha, NF-kappa B remains induced under these conditions. We now report that I kappa B beta is also resynthesized in stimulated cells and appears as an unphosphorylated protein. The unphosphorylated I kappa B beta forms a stable complex with NF-kappa B in the cytosol; however, this binding fails to mask the nuclear localization signal and DNA binding domain on NF-kappa B, and the I kappa B beta-NF-kappa B complex enters the nucleus. It appears therefore that during prolonged stimulation, I kappa B beta functions as a chaperone for NF-kappa B by protecting it from I kappa B alpha and allowing it to be transported to the nucleus.
Keywords
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