Initiator and Executioner Caspases Share All of the Following Features

Question

Initiator and executioner caspases share all of the following features EXCEPT that ...
A) they are cysteine proteases (they have a cysteine residue at their active site).
B) their inactive form is a monomer.
C) they undergo cleavage during activation.
D) their active form is a dimer.
E) they are inhibited by IAPs.

Accepted Answer

Caspases are cysteine proteases that are normally activated in apoptosis through proteolytic cleavage by other caspase molecules and formation of active dimers. Both initiator and executioner caspases can be inhibited by inhibitors of apoptosis (IAPs). While inactive initiator caspases are monomers, inactive executioner caspases are dimers.