In the intrinsic (mitochondrial) pathway of apoptosis, cytochrome c release from mitochondria is promoted by which pro-apoptotic BCL2 family member acting as a 'BH3-only' sensor?
- A BCL-XL
- B MCL-1
- C BIM ✓
- D XIAP
Correct answer: C. BIM
Explanation
BIM is a BH3-only pro-apoptotic protein that senses cellular stress and antagonizes anti-apoptotic BCL2/BCL-XL, allowing BAX/BAK oligomerization and mitochondrial outer membrane permeabilization with cytochrome c release. BCL-XL and MCL-1 are anti-apoptotic members that sequester BH3-only proteins. XIAP is an inhibitor of apoptosis protein that blocks caspase-3/9.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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