In cervical carcinoma caused by human papillomavirus, the viral protein responsible for degradation of the p53 protein acts by:

• A Phosphorylating p53 and preventing its nuclear translocation
• B Binding p53 and recruiting ubiquitin ligase activity that targets it for proteasomal destruction ✓
• C Binding the retinoblastoma protein and releasing E2F transcription factor
• D Inhibiting transcription of the TP53 gene through promoter methylation

Explanation

The HPV E6 oncoprotein complexes with cellular E6-associated protein (E6AP), a ubiquitin ligase, and directs ubiquitination and proteasomal degradation of p53, removing the G1/S checkpoint. Option C describes the action of E7, not E6: E7 binds hypophosphorylated RB and displaces E2F, promoting S-phase entry. Distinguishing E6-p53 from E7-RB is one of the most frequently examined facts in viral carcinogenesis.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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