title: Jun kinase delays caspase-9 activation by interaction with the apoptosome.
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.
authors.affiliation: Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
authors.forename: Thanh H
authors.initials: TH
authors.lastname: Tran
authors.forename: Peter
authors.initials: P
authors.lastname: Andreka
authors.forename: Claudia O
authors.initials: CO
authors.lastname: Rodrigues
authors.forename: Keith A
authors.initials: KA
authors.lastname: Webster
authors.forename: Nanette H
authors.initials: NH
authors.lastname: Bishopric
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D053478:Apoptosomes / Q000235:genetics / Q000378:metabolism*; D053477:Apoptotic Protease-Activating Factor 1 / Q000378:metabolism; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D053453:Caspase 9 / Q000235:genetics / Q000378:metabolism*; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D002474:Cell-Free System / Q000187:drug effects / Q000201:enzymology; D045304:Cytochromes c / Q000378:metabolism; D053938:DNA Fragmentation / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects / Q000235:genetics; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008929:Mitochondria, Heart / Q000201:enzymology*; D048055:Mitogen-Activated Protein Kinase 8 / Q000235:genetics / Q000378:metabolism*; D048056:Mitogen-Activated Protein Kinase 9 / Q000235:genetics / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000201:enzymology*; D016877:Oxidants / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects / Q000235:genetics; D051381:Rats
chemical_list: C506594:Apaf1 protein, rat; D053478:Apoptosomes; D053477:Apoptotic Protease-Activating Factor 1; D016877:Oxidants; D000255:Adenosine Triphosphate; D045304:Cytochromes c; D006861:Hydrogen Peroxide; D048056:Mitogen-Activated Protein Kinase 9; D048055:Mitogen-Activated Protein Kinase 8; C506435:Casp9 protein, rat; D053148:Caspase 3; D053453:Caspase 9