Fig. 7. CD40 stimulation of p100 processing requires NIK activity. (A–C) CD40-293 cells were transfected with plasmids encoding Myc-NIKΔN (NIKΔN) or with no insert as a control (EV). Cells were stimulated as indicated. Lysates (A and B) or cytoplasmic and nuclear fractions (C) were western blotted. Equivalent expression of Myc-NIKΔN was confirmed by western blotting (data not shown). (D and E) Splenic B cells were isolated from aly/aly and aly/+ mice. Cells were stimulated with CD40L for 0.5 or 4 or 5 h, or left unstimulated (0). Cytoplasmic and nuclear fractions were western blotted.