10.1371/journal.pone.0023061.g004 Figure 4  CD40-induced activation of NF-κB and JNK is defective in HOIP-deficient cells.
CD40-mediated signaling was defective in HOIP-deficient cells (HOIP-/- + pMIP), but intact in parental cells transduced with an empty retroviral vector (A20.2J + pMIP) and in HOIP-deficient cells transduced with a retroviral vector encoding HOIP (HOIP-/- + HOIP). Cells were activated with CD154-expressing insect cells for the times indicated. As a negative control, cells were stimulated with insect cells lacking CD154 (5 minute time point only). Western blots of whole-cell lysates were probed with the indicated antibodies. Phospho-IκBα (pIκBα) and phospho-JNK (pJNK) blots were stripped and reprobed for total IκBα and total JNK, respectively (anti-JNK antibodies recognize p46 and p54 isoforms). IκBα blots were also reprobed for actin to demonstrate equal lane loading. Molecular weights are indicated at right. Similar results were obtained in a second experiment and in two additional experiments with a second HOIP-deficient clone.