The Bcl-2 protein was first identified based on its overexpression in a subset of B cell lymphomas, where it was shown to promote the resistance of the tumor cells to apoptosis. Subcellular localization experiments would show that Bcl-2 is present:
A) In the nucleus, where it blocks DNA fragmentation
B) In the cytotoxic granules where it inactivates granzymes
C) In the mitochondria where it blocks cytochrome c release
D) In the cytosol where it blocks caspase activation
E) In the plasma membrane where it blocks death receptor signaling

Question

Quizplus · Accepted Answer

Subcellular localization experiments have shown that Bcl-2 is present in the mitochondria, where it blocks the release of cytochrome c and thus inhibits the initiation of the apoptotic cascade.

The Bcl-2 Protein Was First Identified Based on Its Overexpression