IκB Kinase ϵ Interacts with p52 and Promotes Transactivation via p65

Claudia Wietek,Catherine S Cleaver,Valerie Ludbrook,Jonathan Wilde,Julia White,David J Bell,Michael Lee,Marion Dickson,Keith P Ray,Luke A.J O'Neill

doi:10.1074/jbc.m607018200

Abstract

IκB Kinase ϵ Interacts with p52 and Promotes Transactivation via p65

Highlights

The members of the NF-␬B transcription factor family activate defense responses against pathogens and cellular stress
The active NF-␬B subunits are released, translocate to the nucleus as dimers to bind their cognate target sites, and undergo further phosphorylation, which promotes their ability to transactivate gene expression. p50 and p52 are different from the other factors in that their activation is not controlled by I␬B subunits but rather by the inhibitory ankyrin repeats in the C termini of their fulllength forms, p105 and p100
IKK⑀ was immunoprecipitated from HeLa cell lysates prepared before and after stimulation with 10 ng/ml TNF␣ for 24 h

Summary

Introduction

The members of the NF-␬B transcription factor family activate defense responses against pathogens and cellular stress. The canonical p65/p50 heterodimer is activated by IKK␤ in the IKK␣-IKK␤-NEMO (NF-␬B essential modulator) complex (8 –12) and binds to its target sequence usually within 0.5 h after stimulation to induce transcription of immediate response genes such as those encoding interleukin (IL)-1␤ and tumor necrosis factor-␣ (TNF␣). Nuclear extracts were incubated at room temperature for 30 min with 10,000 cpm double-stranded [␥-32P]ATP and NF-␬B binding sequence (5Ј-AGTTGAGGGGACTTTCCCAGGC-3Ј) in hybridization buffer (10 mM Tris-HCl (pH 7.5), 100 mM NaCl, 1 mM EDTA, 5 mM dithiothreitol, 4% glycerol, and 100 ␮g/ml nuclease-free bovine serum albumin) containing 2 ␮g/ml poly(dI-dC) as a nonspecific competitor.

Results

Conclusion