High-risk HPV types contribute to cervical carcinogenesis through their early proteins. Which action of the E6 protein accounts for its oncogenic role?

• A Binding retinoblastoma protein and releasing E2F transcription factor
• B Inactivating the catalytic subunit of telomerase
• C Recruiting E6-associated protein ligase to ubiquitinate and degrade p53 ✓
• D Hypermethylating the promoter of the CDKN2A gene

Explanation

E6 binds the E6-associated protein (E6AP), an E3 ubiquitin ligase, directing ubiquitination and proteasomal degradation of p53, thereby disabling apoptosis and cell cycle arrest after DNA damage. Option A is the function of E7, which binds hypophosphorylated RB and frees E2F, and it is the single most tempting distractor. E6 also activates telomerase rather than inhibiting it (option B). CDKN2A silencing occurs in other cancers by methylation, not via HPV proteins.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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