ABSTRACT

Members of the caspase family of cysteine proteases play key roles in signal transduction cascades in apoptosis (programmed cell death) and inflammation. Caspases are normally expressed as inactive precursor enzymes (zymogens), a subset of which become activated during apoptosis and coordinate the demolition of the cell from within. To date, three major apoptosis-associated pathways to caspase activation have been elucidated. Certain caspases, such as caspases-1, -4, and -5, also play key roles in signaling pathways associated with immune responses to microbial pathogens.