FIG. 7.

Expression of TRAF6 restores the CD40 signaling deficiency in TRAF6^−/− CD40 fibroblasts. Cells were infected with a TRAF6 or control (CNTR) retrovirus (rv) in two successive 12-h incubations, as described in Materials and Methods. At 36 h postinfection, cells were reseeded and selected for puromycin resistance during a 2-week period. Antibiotic-resistant clones were expanded and either examined for TRAF6 expression (A) or stimulated with CD40L for 0 or 20 min and analyzed for the activation status of JNK, p38, or Akt or for the levels of endogenous IκBα by immunoblot (B). IVK, in vitro kinase assay.