Caspases are activated during apoptosis and cleave specific proteins, resulting in the
irreversible commitment to cell death. The signal transduction proteins MEKK1, p21-
activated kinase 2, and focal adhesion kinase are caspase substrates that contribute to the
cell death response when cleaved. Thirty additional signaling proteins were screened for
their ability to be cleaved during apoptosis. Twenty-two of these proteins were not affected in
Jurkat cells stimulated to undergo apoptosis by Fas ligation, exposure to ultraviolet-C or …