A Tangled Web of Ubiquitin Chains: Breaking News in TNF-R1 Signaling

A flurry of recent revelations is challenging the current dogma on how ubiquitin-dependent processes culminate in the activation of NF-kappa B, by TNF. Here, we integrate these findings into a model for TNF-R1 signaling-and underscore the importance of individual components, including linear ubiquitin chains-which allows for the remarkable versatility of the ubiquitin system.