Association of E6AP (UBE3A) with human papillomavirus type 11 E6 protein.

The cellular E3 ubiquitin ligase E6AP (UBE3A) interacts with the cancer-associated HPV E6 oncoproteins, where together with the viral E6 oncoprotein it binds and targets the degradation of the p53 tumor suppressor. We find that the HPV-11E6 protein also associates with E6AP in vivo, and thereby can target the degradation of an E6-associated protein. Mutation of an E6-binding LXXLL peptide motif on E6AP eliminated the association, revealing a common mode of interaction between high- and low-risk E6 proteins and E6AP. E6AP was required for the in vivo degradation of DLG1 by both HVP-18 E6 and a chimeric HPV-11E6. The common functional interaction of both cancer-associated and non-cancer-associated E6 proteins with E6AP establishes a common mechanism for E6 proteins trophic to mucosal squamous epithelium.