Indicate which of the following mutations would likely promote apoptosis in cell
ID: 79012 • Letter: I
Question
Indicate which of the following mutations would likely promote apoptosis in cells harboring the mutation.
a. Mutations in the pro-apoptotic effector Bcl2 family proteins Bax and Bak that prevent their association with the outer mitochondrial membrane.
b. A mutation in the BIR domain of the IAP protein DIAP1 that prevents binding to either caspases or anti-IAP proteins.
c. A mutation in the anti-IAP protein Reaper that prevents its binding to the IAP proteins.
d. A mutation in the CARD domain of caspase-9 that prevents its binding to Apaf1.
Explanation / Answer
Bax and Bak are proapoptotic proteins with BH 1- 3 domain. Apoptosis by canonical pathway in animal cells is acheived by activation of cell death stimuli either transcriptionally or post-transcriptionally and activation of BH3-only effectors, the multi-domain BH1-3 pro-apoptotic proteins, BAX and BAK. The BH1-3 pro-apoptotic proteins undergo conformational activation leading to oligomerization and insertion in the outer mitochondrial membrane. This process leads to release of apoptogenic factors such as cytochrome c that activate the caspase cascade leading to cellular demise. Option a is correct.