A cytochrome ofree fly apoptosome

摘要

The canonical caspase activation pathway, as first elucidated in the worm Caenorhabditis elegans, is largely conserved in metazoans. Recent structural and biochemical data demonstrate that in C. elegans, the caspase CED-3 is activated by a tetrameric CED-4 complex (apoptosome) that is prevented from assembling by interaction with the Bcl-2-like protein CED-9 until the BH-3-only protein EGL-1 sequesters CED-9 away.1 CED-4 and its orthologues thus facilitate the activation of apical caspases (CED-3 and its orthologues) and provide a key regulatory step in the initial activation of caspases. The formation of the caspase-activating apoptosome in mammals is well documented and a recent publication from Christopher Akey's laboratory now reports the assembly and three-dimensional structure of a Drosophila apoptosome.