title: 4-Hydroxynonenal self-limits fas-mediated DISC-independent apoptosis by promoting export of Daxx from the nucleus to the cytosol and its binding to Fas.
abstract: Previously, we have shown that 4-hydroxynonenal (4-HNE) induces Fas-mediated apoptosis in HLE B-3 cells through a pathway which is independent of FasL, FADD, procaspase 8, and DISC (Li, J., et al. (2006) Biochemistry 45, 12253-12264). The involvement of Daxx has also been suggested in this pathway, but its role is not clear. Here, we report that Daxx plays an important regulatory role during 4-HNE-induced, Fas-mediated apoptosis in Jurkat cells. 4-HNE induces Fas-dependent apoptosis in procaspase 8-deficient Jurkat cells via the activation of ASK1, JNK, and caspase 3, and the apoptosis can be inhibited by masking Fas with the antagonistic anti-Fas antibodies. We demonstrate that 4-HNE exposure to Jurkat cells leads to the induction of both Fas and Daxx. 4-HNE binds to both Fas and Daxx and promotes the export of Daxx from the nucleus to the cytosol, where it binds to Fas and inhibits apoptosis. Depletion of Daxx results in an increase in the activation of ASK1, JNK, and caspase 3 along with exacerbation of 4-HNE-induced apoptosis, suggesting that Daxx inhibits apoptosis by binding to Fas. 4-HNE-induced translocation of Daxx is also accompanied by the activation of the transcription factor HSF1. The results of these studies are consistent with a model in which, by interacting with Fas, 4-HNE promotes proapoptotic signaling via ASK1, JNK, and caspase 3. In parallel, 4-HNE induces Daxx and promotes its export from the nucleus to the cytosol, where it interacts with Fas to self-limit the extent of apoptosis by inhibiting the downstream proapoptotic signaling. Cytoplasmic translocation of Daxx also results in up-regulation of HSF1-associated stress-responsive genes.
authors: Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas 77555, USA. rsharma@hsc. unt.edu
authors: Rajendra
authors: R
authors: Sharma
authors: Abha
authors: A
authors: Sharma
authors: Seema
authors: S
authors: Dwivedi
authors: Piotr
authors: P
authors: Zimniak
authors: Sanjay
authors: S
authors: Awasthi
authors: Yogesh C
authors: YC
authors: Awasthi
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D000447:Aldehydes / Q000494:pharmacology*; D000873:Anthracenes / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D053148:Caspase 3 / Q000378:metabolism; D053181:Caspase 8 / Q000378:metabolism; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism*; D002470:Cell Survival / Q000187:drug effects; D056970:Co-Repressor Proteins; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D053418:Death Domain Receptor Signaling Adaptor Proteins / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D053222:Fas Ligand Protein / Q000378:metabolism*; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D000076249:Heat Shock Transcription Factors; D006801:Humans; D047468:Immunoprecipitation; D048031:JNK Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors; D019169:Jurkat Cells; D048848:MAP Kinase Kinase Kinase 5 / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D018832:Molecular Chaperones; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects; D034741:RNA, Small Interfering / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000447:Aldehydes; D000873:Anthracenes; D056970:Co-Repressor Proteins; C106985:DAXX protein, human; D004268:DNA-Binding Proteins; D053418:Death Domain Receptor Signaling Adaptor Proteins; D053222:Fas Ligand Protein; C000619706:HSF1 protein, human; D018840:HSP70 Heat-Shock Proteins; D000076249:Heat Shock Transcription Factors; D018832:Molecular Chaperones; D009687:Nuclear Proteins; D034741:RNA, Small Interfering; D014157:Transcription Factors; C432165:pyrazolanthrone; D048031:JNK Mitogen-Activated Protein Kinases; D048848:MAP Kinase Kinase Kinase 5; C482858:MAP3K5 protein, human; D053148:Caspase 3; D053181:Caspase 8; C027576:4-hydroxy-2-nonenal