Abstract
Activation of c-Jun N-terminal kinase 1/2 (JNK) can delay oxidant-induced cell death, but the mechanism is unknown. We found that oxidant stress of cardiac myocytes activated both JNK and mitochondria-dependent apoptosis and that expression of JNK inhibitory mutants accelerated multiple steps in this pathway, including the cleavage and activation of caspases-3 and -9 and DNA internucleosomal cleavage, without affecting the rate of cytochrome c release; JNK inhibition also increased caspase-3 and -9 cleavage in a cell-free system. On activation by GSNO or H(2)O(2), JNK formed a stable association with oligomeric Apaf-1 in a approximately 1.4-2.0 mDa pre-apoptosome complex. Formation of this complex could be triggered by addition of cytochrome c and ATP to the cell-free cytosol. JNK inhibition abrogated JNK-Apaf-1 association and accelerated the association of procaspase-9 and Apaf-1 in both intact cells and cell-free extracts. We conclude that oxidant-activated JNK associates with Apaf-1 and cytochrome c in a catalytically inactive complex. We propose that this interaction delays formation of the active apoptosome, promoting cell survival during short bursts of oxidative stress.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Adenosine Triphosphate / metabolism
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Animals
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Apoptosomes / genetics
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Apoptosomes / metabolism*
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Apoptotic Protease-Activating Factor 1 / metabolism
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Caspase 3 / genetics
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Caspase 3 / metabolism
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Caspase 9 / genetics
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Caspase 9 / metabolism*
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Cell Survival / drug effects
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Cell Survival / genetics
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Cell-Free System / drug effects
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Cell-Free System / enzymology
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Cytochromes c / metabolism
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DNA Fragmentation / drug effects
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Enzyme Activation / drug effects
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Enzyme Activation / genetics
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Hydrogen Peroxide / pharmacology
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Mitochondria, Heart / enzymology*
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Mitogen-Activated Protein Kinase 8 / genetics
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Mitogen-Activated Protein Kinase 8 / metabolism*
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Mitogen-Activated Protein Kinase 9 / genetics
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Mitogen-Activated Protein Kinase 9 / metabolism*
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Myocytes, Cardiac / enzymology*
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Oxidants / pharmacology
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Oxidative Stress / drug effects
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Oxidative Stress / genetics
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Rats
Substances
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Apaf1 protein, rat
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Apoptosomes
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Apoptotic Protease-Activating Factor 1
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Oxidants
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Adenosine Triphosphate
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Cytochromes c
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Hydrogen Peroxide
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Mitogen-Activated Protein Kinase 9
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Mitogen-Activated Protein Kinase 8
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Casp9 protein, rat
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Caspase 3
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Caspase 9