Cell stress-associated caspase activation: intrinsically complex?
Apoptosis, or programmed cell death, involves the activation of the caspases, a family of cysteine proteases that coordinate the process of cellular demolition. In the intrinsic--or mitochondrial--pathway to apoptosis, which is initiated in response to various types of cell stress, the prevailing view is that caspases become activated in a structure called the apoptosome after cytochrome c is released from the mitochondria. However, recent research challenges this view and suggests that one or more caspases are activated before mitochondrial release of cytochrome c and that the apoptosome acts as an amplifier, rather than as an initiator, of apoptosis-associated caspase activation. Here, we critically discuss the evidence in support of the latter view and suggest that revision of the established pathway may be premature.
Creagh
Emma M
EM
Molecular Cell Biology Laboratory, Department of Genetics, The Smurfit Institute, Trinity College, Dublin 2, Ireland.
Martin
Seamus J
SJ
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D020169:Caspases / Q000502:physiology*; D004789:Enzyme Activation / Q000502:physiology; D006801:Humans; D013312:Stress, Physiological / Q000201:enzymology* / Q000473:pathology
D020169:Caspases