HPV18 E6 protein (Human papillomavirus type 18 E6 protein) (E6)

The HPV18 E6 protein is a viral oncoprotein from high-risk human papillomavirus type 18, characterized by two zinc-binding domains and a C-terminal PDZ-binding motif (e.g., R-R-R-E-T-Q-V). It plays a principal role in cellular transformation by binding E6AP to ubiquitinate and degrade host proteins like p53, MAGI-1, SAP97/hDlg, and AIF, thereby disrupting apoptosis, cell cycle control, and tumor suppression. This enables cell immortalization and malignancy, particularly in cervical cancer. Structural studies show E6's peptide forms an extended β-sheet with PDZ grooves, with unique residues like R-5 enhancing specificity. High-risk E6 variants exhibit stronger PDZ interactions than low-risk types

Other names

HPV-18 E6HPV18 E6 oncoproteinE6 oncoprotein

Binds PDZ domains of MAGUK proteins (e.g., MAGI-1, SAP97) via C-terminal peptide motif for ubiquitin-mediated degradation Forms complex with E6AP (E3 ubiquitin ligase) to degrade p53 and AIF Targets class I PDZ domain-containing proteins for proteasomal degradation