Which pair correctly matches an initiator caspase with its pathway of activation?

• A Caspase-8 with the intrinsic mitochondrial pathway; caspase-9 with the extrinsic death receptor pathway
• B Caspase-12 with both pathways; caspase-3 as the sole initiator
• C Caspase-3 with the intrinsic pathway; caspase-6 with the extrinsic pathway
• D Caspase-9 with the intrinsic mitochondrial pathway; caspase-8 with the extrinsic death receptor pathway ✓

Explanation

In the extrinsic pathway, ligation of Fas or TNF receptors recruits FADD and activates caspase-8, the initiator caspase. In the intrinsic pathway, cytochrome c released from mitochondria binds Apaf-1 to form the apoptosome, which activates caspase-9. Caspase-3 and caspase-7 are executioner caspases activated downstream by either initiator, not initiators themselves. This distinction between initiator and executioner caspases is a standard Robbins fact.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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