Caspase-3 (CASP-3) is involved in the activation of caspases responsible for apoptosis e, Xenopus/Amphibian,ecution. At the onset of apoptosis it proteolytically cleaves poly(ADP-ribose) polymerase (PARP) at a '216-Asp-|-Gly-217' bond. Caspase-3 cleaves and activates sterol regulatory element binding proteins (SREBPs) between the basic heli, Xenopus/Amphibian,-loop-heli, Xenopus/Amphibian, leucine zipper domain and the membrane attachment domain. Caspase-3 cleaves and activates caspase-6, -7 and -9, and is involved in the cleavage of huntingtin.