Q.34

The component(s) of the apoptosome is/are

(A) cytochrome c

(B) procaspase 9

(C) caspase 3

(D) caspase 8

Apoptosome Components: Cytochrome C and Procaspase 9 Explained

The apoptosome forms a key complex in the intrinsic apoptosis pathway, primarily consisting of cytochrome c and procaspase 9 along with Apaf-1.

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Correct Answer

The components of the apoptosome are (A) cytochrome c and (B) procaspase 9. Cytochrome c release from mitochondria binds Apaf-1, triggering oligomerization into a wheel-like structure that recruits and activates procaspase 9.

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Option Breakdown

Cytochrome C (A)

Cytochrome c acts as the initiator by binding to Apaf-1 in the cytosol with dATP, essential for apoptosome assembly in mammalian cells.

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Procaspase 9 (B)

Procaspase 9 docks onto the apoptosome via CARD domains, undergoing activation to initiate downstream caspase cascade.

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Caspase 3 (C)

Caspase 3 serves as an effector caspase activated by active caspase 9 from the apoptosome, but does not form part of the core complex.

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Caspase 8 (D)

Caspase 8 functions in the extrinsic apoptosis pathway via death receptors, independent of the apoptosome.

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