Cleavage of poly(ADP-ribose) polymerase by interleukin-1 beta converting enzyme and its homologs TX and Nedd-2.
The proteolytic cleavage of poly(ADP-ribose) polymerase (PARP) is an early biochemical event, which occurs during apoptosis. A recent study suggested that PARP cleavage can be mediated by a novel cytosolic protease (prICE) that resembles interleukin-1 beta converting enzyme (ICE), but cannot be mediated by ICE itself (Lazebnik, Y.A., Kaufmann, S.H., Desnoyers, S., Poirier, G.G., and Earnshaw, W.C. (1994) Nature 371, 346-347). We have used a COS cell co-transfection assay to investigate if ICE or any known ICE-like protease is active in PARP cleavage within the cell. Here we report that co-expression of human PARP with human ICE, or the ICE homologs TX and Nedd-2, resulted in a cleavage of PARP identical to that observed in apoptotic cells. Experiments with purified recombinant human ICE indicated that PARP polypeptide can be specifically cleaved in vitro by ICE in a time- and enzyme concentration-dependent manner. PARP cleavage, however, requires a 50-100-fold higher ICE concentration than does processing of the interleukin-1 beta precursor at an equivalent substrate concentration. The abilities of ICE, TX, and Nedd-2, when expressed at high intracellular concentrations, to cleave PARP are consistent with their induction of apoptosis in transfected cells.
Gu
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Vertex Pharmaceuticals Incorporated, Cambridge, Massachusetts 02139-4211, USA.
Sarnecki
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C
Aldape
R A
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Livingston
D J
DJ
Su
M S
MS
D000595:Amino Acid Sequence; D001483:Base Sequence; D020170:Caspase 1; D053143:Caspase 2; D020169:Caspases; D053471:Caspases, Initiator; D002478:Cells, Cultured; D003546:Cysteine Endopeptidases / Q000494:pharmacology*; D006801:Humans; D008969:Molecular Sequence Data; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*; D011506:Proteins / Q000494:pharmacology*
D011506:Proteins; D011065:Poly(ADP-ribose) Polymerases; C093516:CASP4 protein, human; D053143:Caspase 2; D020169:Caspases; D053471:Caspases, Initiator; D003546:Cysteine Endopeptidases; D020170:Caspase 1