CD40 induces phosphorylation of AKT and ERK in a dose- and time-dependent manner.

Serum-starved MM.1S cells were activated by CD40 by incubation with anti-CD40 mAb (G28.5 or 626.1) at the indicated concentrations for 15 minutes (A) or with G28.5 (2 μg/mL) for 0 to 240 minutes (B). Samples were collected and analyzed by Western blotting with antiphosphorylation-specific Abs. Detection of total AKT on the same blots was used to demonstrate equal loading of samples. Lysates were also probed for pJNK and p38 using specific antiphospho Abs.