Description
Cysteine-aspartic acid protease 3, also known as Apopain, CPP32, CPP32B, and YAMA, is a member of the cysteine-aspartic acid protease family. Western blot analysis of three cell lines revealed the prominent CASP3 band at 32 kD and 20 kD. Several human cancer cell lines showed coexpression of both variants at the mRNA and protein levels. Overexpression of the catalytically inactive Caspase-3 by human kidney cells offered some resistance to inducers of apoptosis, and CASP3 accumulation could be enhanced with addition of proteasome inhibitors. Sequential activation of caspases plays a central role in the execution-phase of cell apoptosis. Alternative splicing of this gene results in two transcript variants that encode the same protein. Orthologs have been identified in numerous mammals for which complete genome data are available. Unique orthologs are also present in birds, lizards, lissamphibians, and teleosts. Nicholson et al. developed a potent peptide aldehyde inhibitor and showed that it prevented apoptotic events in vitro, suggesting that the protein is important for the initiation of apoptotic cell death