Manipulation of the ubiquitin–proteasome pathway by small DNA tumor viruses

Viruses have evolved to use cellular pathways to their advantage, including the ubiquitin–proteasome pathway of protein degradation. In several cases, viruses produce proteins that highjack cellular E3 ligases to modify their substrate specificity in order to eliminate unwanted cellular proteins, in particular inhibitors of the cell cycle. They can also inhibit E3 ligase to prevent specific protein degradation or even use the system to control the level of expression of their own proteins. In this review we explore the specific ways that small DNA tumor viruses exploit the ubiquitin–proteasome pathway for their own benefit.