Role of proteases in activation of apoptosis

Programmed cell death, or apoptosis, is a physiological cell suicide mechanism, which is triggered in the cells by different stimuli. It has been shown that proteases play a significant role both in the target cell killing by cytotoxic lymphocytes and in the TNF- or anti-Fas-induced cell death. The proteases involved in the early (induction) and late (cell self-destruction) stages of apoptosis are reviewed. It is suggested that the late stages are connected with the activation of a cascade of intracellular proteases, which leads to massive protein destruction. It is likely that the protein destruction is mainly designed for preventing autoimmune response to proteins released from dying cells.