Role of ICE-related and other proteases in Fas-mediated apoptosis.

Interleukin-1beta-converting enzyme (ICE)-like proteases comprise a novel family of unusual cysteine proteases which have been implicated in programmed cell death in both invertebrates and mammals. Current available evidence indicates a role of ICE proteases as central executioners of apoptosis triggered by the cell surface receptor Fas (APO-l). The presence of multiple mammalian ICE proteases with partially overlapping but distinct activities suggests a complex proteolytic cascade which is induced upon Fas ligation. The precise role of single members of the ICE family in Fas-mediated apoptosis, however, is still unclear. Here, we summarize the present knowledge about the relevance of ICE proteases, their potential targets, and interaction with unrelated proteases in cell death mediated by Fas and other apoptotic stimuli.