The Bcl2 family is comprised of anti-apoptotic (A), BH3-only (
B), and effector (
E) proteins. In the following diagram representing the regulation of the intrinsic pathway of apoptosis, what class of activated Bcl2 family proteins (A, B, or
E) corresponds to boxes 1 to 3, respectively? Your answer would be a three-letter string composed of letters A, B, and E only, e.g. ABE.

Question

The Bcl2 family is comprised of anti-apoptotic (A), BH3-only (
B), and effector (
E) proteins. In the following diagram representing the regulation of the intrinsic pathway of apoptosis, what class of activated Bcl2 family proteins (A, B, or 
E) corresponds to boxes 1 to 3, respectively? Your answer would be a three-letter string composed of letters A, B, and E only, e.g. ABE.

Quizplus · Accepted Answer

The pro-apoptotic effector Bcl2 family proteins such as Bax and Bak induce the release of cytochrome c and other mitochondrial intermembrane proteins into the cytosol. Anti-apoptotic Bcl2 family proteins, such as Bcl2 and BclXL, inhibit these effector proteins and are in turn inhibited by the pro-apoptotic BH3-only proteins such as Bid and Bim. Some BH3-only proteins may also directly activate Bax and Bak (not shown).

The Bcl2 Family Is Comprised of Anti-Apoptotic (A), BH3-Only (B)