Mechanisms mediating caspase activation in cell death.
The initial activation of a caspase in a caspase cascade is a crucial event that determines whether a cell will ultimately undergo cell death. Although each cell contains a number of different caspases, only a small subset may be required for apoptosis in response to a specific stimulus. It now seems that each caspase cascade has two types of caspases involved, the upstream or class I caspases, and the downstream or class II caspases. Class I caspases are characterised by long amino-terminal prodomains that carry specific protein - protein interaction domains which mediate oligomerisation of caspases, often assisted by specific adaptor molecules. Oligomerisation appears to be sufficient for autocatalytic activation of class I caspases. Once the first caspase in the pathway has been activated, it processes downstream caspases initiating a cascade of amplifying events that lead to the apoptotic death of a cell. This article reviews our current understanding of mechanisms that mediate the activation of caspases.
Kumar
S
S
Hanson Centre for Cancer Research, Institute of Medical and Veterinary Science, Frome Road, Adelaide, Australia. sharad.kumar@imvs.sa.gov.au
D000818:Animals; D017209:Apoptosis; D001665:Binding Sites; D020169:Caspases / Q000378:metabolism*; D016923:Cell Death; D004789:Enzyme Activation; D004792:Enzyme Precursors / Q000378:metabolism; D006801:Humans
D004792:Enzyme Precursors; D020169:Caspases