The nematode worm Caenorhabditis elegans has been used with great success to identify the basic components of the machinery underlying apoptosis (programmed cell death). Indeed, of the three key cell death genes that have been identified in C. elegans, two -
ced-3 and
ced-9 - have mammalian homologues that also function in apoptosis. But the sequence of the third gene,
ced-4, revealed no obvious mammalian homologue, and precious little in terms of possible mechanism of action. A flurry of activity has changed that. A paper by Zou et al., published earlier this month in Cell, provides a homologue. And work by Chinnaiyan et al. (page 728 of this issue) and by Seshagiri and Miller in Current Biology lays down some choreography for the part that CED-4 protein plays in the molecular dance of death.