Caspase activation without death

Since molecular cloning of the C. elegans ced-3 gene revealed its homology with mammalian IL-1 beta-converting enzyme,(1) 14 members of the caspase fa mily have been identified, which have often been involved as mediators of o ne or more phases of the apoptotic process.(2,3) However, an over-simplifie d role of these proteases may be insufficient to explain the usually consti tutive expression of such a large and complex family of enzymes, many of wh ich display overlapping specificity. In addition to the well-established ro le of caspase-1 in the production of active IL-1 beta and IL-18 in inflamma tion,(4) an increasing number of reports has recently suggested that caspas es may have a function outside of apoptosis. In this review, the situations in which cells survive despite the presence of activated caspases in their cytoplasm will be examined and discussed, with the intent to gather all re cent advances in this new field that promises to be a focus for caspase res earch in the near future.