Human papillomavirus oncoproteins and post-translational modifications: generating multifunctional hubs for overriding cellular homeostasis

Human papillomaviruses (HPVs) are major human carcinogens, causing around 5% of all human cancers, with cervical cancer being the most important. These tumors are all driven by the two HPV oncoproteins E6 and E7. Whilst their mechanisms of action are becoming increasingly clear through their abilities to target essential cellular tumor suppressor and growth control pathways, the roles that post-translational modifications (PTMs) of E6 and E7 play in the regulation of these activities remain unclear. Here, we discuss the direct consequences of some of the most common PTMs of E6 and E7, and how this impacts upon the multi-functionality of these viral proteins, and thereby contribute to the viral life cycle and to the induction of malignancy. Furthermore, it is becoming increasingly clear that these modifications, may, in some cases, offer novel routes for therapeutic intervention in HPV-induced disease.