During the extrinsic (death receptor) pathway of apoptosis, binding of Fas ligand to the Fas receptor (CD95) directly leads to which of the following events?
- A Oligomerization of BAX and BAK in the mitochondrial outer membrane
- B Recruitment of FADD and procaspase-8 to form the death-inducing signaling complex ✓
- C Formation of the apoptosome with cytochrome c and APAF-1
- D Release of SMAC/DIABLO from mitochondria to inhibit IAPs
Correct answer: B. Recruitment of FADD and procaspase-8 to form the death-inducing signaling complex
Explanation
The extrinsic pathway is initiated when death ligands (FasL, TNF) bind death receptors, recruiting the adaptor FADD and procaspase-8 to form the death-inducing signaling complex (DISC). Caspase-8 is then activated directly. Options A, C, and D describe events in the intrinsic (mitochondrial) pathway of apoptosis.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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