Role of Unphosphorylated, Newly Synthesized IκBβ in Persistent Activation of NF-κB
Open Access
- 1 October 1996
- journal article
- Published by Taylor & Francis in Molecular and Cellular Biology
- Vol. 16 (10) , 5444-5449
- https://doi.org/10.1128/mcb.16.10.5444
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
This publication has 23 references indexed in Scilit:
- NF-κB: A lesson in family valuesCell, 1995
- IκB-β regulates the persistent response in a biphasic activation of NF-κBCell, 1995
- Structure of NF-κB p50 homodimer bound to a κB siteNature, 1995
- Function and Activation of NF-kappaB in the Immune SystemAnnual Review of Immunology, 1994
- Rapid proteolysis of IκB-α is necessary for activation of transcription factor NF-κBNature, 1993
- The oncoprotein Bcl-3 directly transactivates through κB motifs via association with DNA-binding p50B homodimersCell, 1993
- I kappa B interacts with the nuclear localization sequences of the subunits of NF-kappa B: a mechanism for cytoplasmic retention.Genes & Development, 1992
- Cytosolic proteins that specifically bind nuclear location signals are receptors for nuclear importCell, 1991
- Purified human IκB can rapidly dissociate the complex of the NF-κB transcription factor with its cognate DNACell, 1990
- Activation of DNA-binding activity in an apparently cytoplasmic precursor of the NF-κB transcription factorCell, 1988