In the extrinsic pathway of apoptosis, binding of Fas ligand to CD95 (Fas) recruits FADD, which then directly activates:
- A Caspase-9 via the apoptosome
- B MLKL via RIPK3 phosphorylation
- C Caspase-3 via cleavage of procaspase-8 ✓
- D Gasdermin D via inflammasome assembly
Correct answer: C. Caspase-3 via cleavage of procaspase-8
Explanation
Fas ligand trimerizes Fas, recruiting FADD through death domains; FADD then binds procaspase-8 via death effector domains, forming the death-inducing signaling complex. Procaspase-8 is activated by induced proximity, cleaves itself, and directly activates executioner caspase-3. Caspase-9 activation via the apoptosome is exclusive to the intrinsic pathway. MLKL and gasdermin D belong to necroptosis and pyroptosis respectively, neither of which involves FADD or caspase-8.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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