Figure 2.

TRAF2 and the cIAPs in receptor-induced activation of the classical and alternative NFκB pathway. The activities of TRAF2 and the cIAPs have opposing qualities in the classical (left panel) and alternative (right panel) NFκB signaling pathway. In the classical NFκB pathway TRAF2 and the cIAPs enable signaling, while in the alternative NFκB pathway they act as inhibitors. Importantly, TNFR-induced recruitment of TRAF2 and the cIAPs, which triggers the classical NFκB pathway, is linked with an “inhibitory” relocation of these molecules away from their cytosolic substrate NIK in the alternative NFκB pathway. Therefore, TNFRs eventually stimulate both NFκB signaling pathways despite the opposing quality they have in these pathways. For more details, refer to main text.