Figure 3.

Hsp27 associates with IKKβ and inhibits IKKβ-induced NF-κB activity. A) WT IKKβ causes a 3-fold increase in NF-κB activation, which is abolished in muscles coinjected with WT IKKβ and Hsp27. Bars represent means ± se; 6 muscles/group. *P < 0.05 vs. control-injected muscles. †P < 0.05 vs. WT IKKβ-injected muscles. B) Immunoprecipitation of Hsp25/27, using an anti-Hsp25/27 antibody, from muscles injected with IKKβ or IKKβ plus Hsp27. Immunoprecipitated samples were separated on a denaturing gel and blotted with anti-FLAG antibody for IKKβ. Endogenous Hsp25 (lane 2) and ectopic Hsp27 (lane 4) both bound in complex with IKKβ-FLAG. A normal IgG antibody was used as negative control for immunoprecipitation. Corresponding samples used for coimmunoprecipitation experiments were subjected to SDS-PAGE and immunoblotted with an anti-FLAG antibody to show that the level of overexpressed IKKβ is similar in each sample.