Viral modulators of cullin RING ubiquitin ligases: culling the host defense.

Cullin RING ubiquitin ligases (CRULs) are found in all eukaryotes and play an essential role in targeting proteins for ubiquitin-mediated destruction, thus regulating a plethora of cellular processes. Viruses manipulate CRULs by redirecting this destruction machinery to eliminate unwanted host cell proteins, thus allowing viruses to slip past host immune barriers. Depending on the host organism, virus-modified CRULs can perform an amazing range of tasks, including the elimination of crucial signal transduction molecules in the human interferon pathway and suppression of virus-induced gene silencing in plants. This Perspective summarizes recent advances in our understanding of how viral proteins manipulate the function of CRULs.