Abstract |
The poly(ADP-ribose) polymerase (PARP-1), a 113 kDa nuclear enzyme, is cleaved in fragments of 89 and 24 kDa during apoptosis. This cleavage has become a useful hallmark of apoptosis and has been shown to be done by DEVD-ase caspases, a family of proteases activated during apoptosis. Interestingly, PARP-1 is also processed during necrosis but a major fragment of 50 kDa is observed. This event is not inhibited by zVAD-fmk, a broad spectrum caspase inhibitor, suggesting that these proteases are not implicated in the necrotic cleavage of PARP-1. Since lysosomes release their content into the cytosol during necrosis, the proteases liberated could produce the cleavage of PARP-1. We therefore isolated lysosomal rich-fractions from Jurkat T cells. Our results reveal that the in vitro lysosomal proteolytic cleavage of affinity purified bovine PARP-1 is composed of fragments corresponding, in apparent molecular weight and function, to those found in Jurkat T cells treated with necrotic inducers like 0.1% H2O2, 10% EtOH or 100 microM HgCl2. Moreover, we used purified lysosomal proteases ( cathepsins B, D and G) in an in vitro cleavage assay and found that cathepsins B and G cleaved PARP-1 in fragments also found with the lysosomal rich-fractions. These findings suggest that the necrotic cleavage of PARP-1 is caused in part or in totality by lysosomal proteases released during necrosis.
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Authors | S Gobeil, C C Boucher, D Nadeau, G G Poirier |
Journal | Cell death and differentiation
(Cell Death Differ)
Vol. 8
Issue 6
Pg. 588-94
(Jun 2001)
ISSN: 1350-9047 [Print] England |
PMID | 11536009
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Cell Extracts
- Peptide Fragments
- Poly(ADP-ribose) Polymerases
- Cathepsins
- Endopeptidases
- Peptide Hydrolases
- Serine Endopeptidases
- CTSG protein, human
- Cathepsin G
- Caspases
- Cathepsin B
- DEVDase
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Topics |
- Amino Acid Sequence
- Animals
- Apoptosis
- Blotting, Western
- Caspases
(metabolism)
- Cathepsin B
(metabolism)
- Cathepsin G
- Cathepsins
(metabolism)
- Cattle
- Cell Extracts
- Endopeptidases
(metabolism)
- Enzyme Activation
- Humans
- Jurkat Cells
- Lysosomes
(enzymology, metabolism)
- Molecular Weight
- Necrosis
- Peptide Fragments
(chemistry, metabolism)
- Peptide Hydrolases
(metabolism)
- Poly(ADP-ribose) Polymerases
(chemistry, metabolism)
- Protein Structure, Tertiary
- Serine Endopeptidases
- Time Factors
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