High-risk human papillomavirus contributes to cervical carcinogenesis through viral oncoproteins that inactivate key cell cycle regulators. The primary action of the E6 protein is:
- A Activation of telomerase reverse transcriptase directly
- B Binding and functional inactivation of RB
- C Binding and degradation of p53 via ubiquitin-mediated proteolysis ✓
- D Inhibition of apoptosis through BCL2 upregulation
Correct answer: C. Binding and degradation of p53 via ubiquitin-mediated proteolysis
Explanation
E6 recruits the cellular E6-associated protein ubiquitin ligase to p53, targeting it for proteasomal degradation and thereby abolishing DNA damage-induced arrest and apoptosis. Inactivation of RB is the function of E7, which kills option B, the most tempting distractor because both proteins act on cell cycle checkpoints. Telomerase activation occurs secondarily as a consequence of p53 loss, not by direct E6 binding.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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