IκBα interaction with cytoskeletal proteins.

A. Space-filling representation of the predicted binding interaction of IκBα with cytoskeletal proteins spectrin and actin. Two orientations of the complex are shown to illustrate binding interactions between the three molecules. β-spectrin is shown in blue, actin in red and IκBα in yellow. B. HeLa cells were transfected with IκBα-EGFP together with a non-targeting siRNA or TILRR siRNA. Cell lysates were immunoprecipitated with an anti-spectrin antibody, and levels of spectrin and of spectrin-associated IκBα determined by immunoblotting, as described in material and methods. C. Quantitation of spectrin associated IκBα-EGFP from western blots of cells transfected with random siRNA (control) or TILRR siRNA, and stimulated with IL-1β (1nM) over time, as in B. Data are presented as fraction of levels in un-stimulated samples (t = 0) and expressed relative to loading control (Mean ±SEM, n = 5, p<0.05 at 60 min).