Macromolecular substrates for the ICE-like proteases during apoptosis.
The interleukin-1 beta-converting enzyme (ICE) family of proteases is an important component of the mechanism of the apoptotic process, but the physiologic roles of the different homologs during apoptosis remain unclear. Significant information about the roles of proteolysis in apoptosis will be gained through identification of the distal substrates through which these proteases achieve their pro-apoptotic effects. Identification of these substrates therefore remains an important challenge. A subset of autoantibodies from patients with systemic lupus erythematosus (SLE) recognize molecules that are specifically cleaved early during apoptosis. Several of the identified autoantigens are nuclear proteins (PARP, U1-70 kDa, and DNA-PKcs) that are substrates for CPP32 in vitro and in apoptotic cells. Of note, these substrates are catalytic proteins involved in homeostatic pathways, suggesting that abolition of homeostasis is one fundamental feature ensuring the rapid irreversibility of the apoptotic process. Identification of the other substrates for this protease family will provide the tools to assess the roles of the different proteases in apoptotic death.
Rosen
A
A
Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
Casciola-Rosen
L
L
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D001323:Autoantibodies / Q000378:metabolism; D001665:Binding Sites; D020170:Caspase 1; D053148:Caspase 3; D020169:Caspases; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D051747:DNA-Activated Protein Kinase; D004268:DNA-Binding Proteins; D006801:Humans; D008177:Lupus Vulgaris / Q000276:immunology*; D009687:Nuclear Proteins; D011065:Poly(ADP-ribose) Polymerases / Q000276:immunology / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D013379:Substrate Specificity
D001323:Autoantibodies; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D011065:Poly(ADP-ribose) Polymerases; D051747:DNA-Activated Protein Kinase; C497263:PRKDC protein, human; D017346:Protein Serine-Threonine Kinases; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; D003546:Cysteine Endopeptidases; D020170:Caspase 1