Searching across hundreds of databases

Our searching services are busy right now. Your search will reload in five seconds.

Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.

Direct phosphorylation of IkappaB by IKKalpha and IKKbeta: discrimination between free and NF-kappaB-bound substrate.

Science (New York, N.Y.) | Aug 28, 1998

A large protein complex mediates the phosphorylation of the inhibitor of kappaB (IkappaB), which results in the activation of nuclear factor kappaB (NF-kappaB). Two subunits of this complex, IkappaB kinase alpha (IKKalpha) and IkappaB kinase beta (IKKbeta), are required for NF-kappaB activation. Purified recombinant IKKalpha and IKKbeta expressed in insect cells were used to demonstrate that each protein can directly phosphorylate IkappaB proteins. IKKalpha and IKKbeta were found to form both homodimers and heterodimers. Both IKKalpha and IKKbeta phosphorylated IkappaB bound to NF-kappaB more efficiently than they phosphorylated free IkappaB. This result explains how free IkappaB can accumulate in cells in which IKK is still active and thus can contribute to the termination of NF-kappaB activation.

Pubmed ID: 9721103 RIS Download

Mesh terms: Animals | Cell Line | Dimerization | Enzyme Activation | HeLa Cells | Helix-Loop-Helix Motifs | Humans | I-kappa B Kinase | Leucine Zippers | Mutation | NF-kappa B | Phosphorylation | Protein-Serine-Threonine Kinases | Proto-Oncogene Proteins | Recombinant Fusion Proteins | Recombinant Proteins | Spodoptera | Transcription Factor RelB | Transcription Factors

Publication data is provided by the National Library of Medicine ® and PubMed ®. Data is retrieved from PubMed ® on a weekly schedule. For terms and conditions see the National Library of Medicine Terms and Conditions.

We have not found any resources mentioned in this publication.