FIG. 10.

Western analysis of IRAK as a function of time after stimulation with IL-1. Shown are results for wild-type 293TK/Zeo (WT) cells and I3A cells (A), I1A cells transfected with IRAK or IRAK-K239A (B), and I1A/I3A heterokaryons (C), either untreated or treated with IL-1. Cell extracts were analyzed by the Western procedure with anti-IRAK. P-IRAK, phosphorylated IRAK; U-IRAK, ubiquitinated IRAK. The top portions of panels A and B are short exposures, and the bottom portions are long exposures. The same transfers were probed with anti-IL-1R1 to control for loading. (D and E) Extracts of I1A cells transfected with IRAK or IRAK-K239A, with or without IL-1 stimulation, were either untreated or treated with calf intestinal phosphatase (CIP).