Caspase inhibitors

Caspases are the key effector molecules of the physiological death process known as apoptosis, although some are involved in activation of cytokines, rather than cell death. They exist in most of our cells as inactive precurs ors (zymogens) that kill the cell once activated. Caspases can be controlle d in two ways. The processing and activation of a caspase can be regulated by molecules such as FADD, APAF-1, Bcl-2 family members, FLIP and IAPs, Act ive caspases can be controlled by a variety of inhibitors that directly int eract with the protease, This review describes the later direct caspase inh ibitors that have been identified, products of both viral and cellular gene s, and artificial caspase inhibitors that have been developed both as resea rch tools and as pharmaceutical agents to inhibit cell death in vivo.