SUPPRESSION OF NEURONAL APOPTOSIS BY S-NITROSYLATION OF CASPASES

S-Nitrosylation (reaction of nitric oxide (NO) species with a critical cysteine sulfhydryl) can regulate the physiological activity of prote ins, including enzymes, ion channels, G-proteins, and transcription fa ctors. Caspases are a family of interleukin-1 beta-converting enzyme-l ike proteases involved in the signaling pathway to apoptotic cell deat h, and each member of this enzyme family contains a critical cysteine residue in its active site. Here we show that S-nitrosylation of caspa ses in human embryonic kidney (HEK)-293 cells and primary cerebrocorti cal neurons decreases enzyme activity and is associated with protectio n from apoptosis. (C) 1997 Elsevier Science Ireland Ltd.