Modulation of the NF-kappa B pathway by virally encoded death effector domains-containing proteins.

Death Effector Domains (DEDs) have been known to mediate the recruitment of Caspase 8 and its homologs to the aggregated death-inducing signaling complex (DISC), consisting of the death domain (DD)-containing receptors and various signaling proteins. In addition, several viruses were recently shown to encode proteins with DEDs (also called FLICE inhibitory proteins or vFLIPs) which have the ability of blocking cell death induced by DD-containing receptors. We provide evidence that vFLIPs can also modulate the NF-kappaB pathway and physically interact with several signaling proteins, such as the TRAFs, RIP, NIK and the IKKs. Modulation of the NF-kappaB pathway may play a role in the natural history of infection by these viruses.