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Death Domain (death + domain)
Selected AbstractsCaspase-8- and JNK-dependent AP-1 activation is required for Fas ligand-induced IL-8 productionFEBS JOURNAL, Issue 9 2007Norihiko Matsumoto Despite a dogma that apoptosis does not induce inflammation, Fas ligand (FasL), a well-known death factor, possesses pro-inflammatory activity. For example, FasL induces nuclear factor ,B (NF-,B) activity and interleukin 8 (IL-8) production by engagement of Fas in human cells. Here, we found that a dominant negative mutant of c-Jun, a component of the activator protein-1 (AP-1) transcription factor, inhibits FasL-induced AP-1 activity and IL-8 production in HEK293 cells. Selective inhibition of AP-1 did not affect NF-,B activation and vice versa, indicating that their activations were not sequential events. The FasL-induced AP-1 activation could be inhibited by deleting or introducing the lymphoproliferation (lpr) -type point mutation into the Fas death domain (DD), knocking down the Fas-associated DD protein (FADD), abrogating caspase-8 expression with small interfering RNAs, or using inhibitors for pan-caspase and caspase-8 but not caspase-1 or caspase-3. Furthermore, wildtype, but not a catalytically inactive mutant, of caspase-8 reconstituted the FasL-induced AP-1 activation in caspase-8-deficient cells. Fas ligand induced the phosphorylation of two of the three major mitogen-activated protein kinases (MAPKs): extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) but not p38 MAPK. Unexpectedly, an inhibitor for JNK but not for MAPK/ERK kinase inhibited the FasL-induced AP-1 activation and IL-8 production. These results demonstrate that FasL-induced AP-1 activation is required for optimal IL-8 production, and this process is mediated by FADD, caspase-8, and JNK. [source] DAP kinase activity is critical for C2 -ceramide-induced apoptosis in PC12 cellsFEBS JOURNAL, Issue 1 2002Mutsuya Yamamoto Exposure of PC12 cells to C2 -ceramide results in dose-dependent apoptosis. Here, we investigate the involvement of death-associated protein (DAP) kinase, initially identified as a positive mediator of the interferon-,-induced apoptosis of HeLa cells, in the C2 -ceramide-induced apoptosis of PC12 cells. DAP kinase is endogenously expressed in these cells. On exposure of PC12 cells to 30 µm C2 -ceramide, both the total (assayed in the presence of Ca2+/calmodulin) and Ca2+/calmodulin-independent (assayed in the presence of EGTA) DAP kinase activities were transiently increased 5.0- and 12.2-fold, respectively, at 10 min, and then decreased to 1.7- and 3.4-fold at 90 min. After 10 min exposure to 30 µm C2 -ceramide, the Ca2+/calmodulin independent activity/ total activity ratio increased from 0.22 to 0.60. These effects were dependent on the C2 -ceramide concentration. C8 -ceramide, another active ceramide analog, also induced apoptosis and activated DAP kinase, while C2 -dihydroceramide, an inactive ceramide analog, failed to induce apoptosis and increase DAP kinase activity. Furthermore, transfection studies revealed that overexpression of wild-type DAP kinase enhanced the sensitivity to C2 - and C8 -ceramide, while a catalytically inactive DAP kinase mutant and a construct containing the death domain and C-terminal tail of DAP kinase, which act in a dominant-negative manner, rescued cells from C2 -, and C8 -ceramide-induced apoptosis. These findings demonstrate that DAP kinase is an important component of the apoptotic machinery involved in ceramide-induced apoptosis, and that the intrinsic DAP kinase activity is critical for ceramide-induced apoptosis. [source] Structure,activity relationship of the p55 TNF receptor death domain and its lymphoproliferation mutantsFEBS JOURNAL, Issue 5 2001Gert De Wilde Upon stimulation with tumor necrosis factor (TNF), the TNF receptor (TNFR55) mediates a multitude of effects both in normal and in tumor cells. Clustering of the intracellular domain of the receptor, the so-called death domain (DD), is responsible for both the initiation of cell killing and the activation of gene expression. To characterize this domain further, TNFR55 DD was expressed and purified as a thioredoxin fusion protein in Escherichia coli. Circular dichroism, steady-state and time-resolved fluorescence spectroscopy were used to compare TNFR55 DD with DDs of the Fas antigen (Fas), the Fas-associating protein with DD (FADD) and p75 nerve growth factor receptor, for which the 3-dimensional structure are already known. The structural information derived from the measurements strongly suggests that TNFR55 DD adopts a similar fold in solution. This prompted a homology modeling of the TNFR DD 3-D structure using FADD as a template. In vivo studies revealed a difference between the two lymphoproliferation (lpr) mutations. Biophysical techniques were used to analyze the effect of changing Leu351 to Ala and Leu351 to Asn on the global structure and its impact on the overall stability of TNFR55 DD. The results obtained from these experiments in combination with the modeled structure offer an explanation for the in vivo observed difference. [source] The adaptor molecule FADD from Xenopus laevis demonstrates evolutionary conservation of its pro-apoptotic activityGENES TO CELLS, Issue 12 2004Kazuhiro Sakamaki FADD is an adaptor protein that transmits apoptotic signals from death receptors such as Fas to downstream initiator caspases in mammals. We have identified and characterized the Xenopus orthologue of mammalian FADD (xFADD). xFADD contains both a death effector domain (DED) and a death domain (DD) that are structurally homologous to those of mammalian FADD. We observed xFADD binding to Xenopus caspase-8 and caspase-10 as well as to human caspase-8 and Fas through interactions with their homophilic DED and DD domains. When over-expressed, xFADD was also able to induce apoptosis in wild-type mouse embryonic fibroblasts (MEF), but not in caspase-8-deficient MEF cells. In contrast, DED-deficient xFADD (xFADDdn) acted as a dominant-negative mutant and prevented Fas-mediated apoptosis in mammalian cell lines. These results indicate that xFADD transmits apoptotic signals from Fas to caspase-8. Furthermore, we found that transgenic animals expressing xFADD in the developing heart or eye under the control of tissue-specific promoters show abnormal phenotypes. Taken together, these results suggest that xFADD can substitute functionally for its mammalian homologue in death receptor-mediated apoptosis, and we suggest that xFADD functions as a pro-apoptotic adaptor molecule in frogs. Thus, the structural and functional similarities between xFADD and mammalian FADD provide evidence that the apoptotic pathways are evolutionally conserved across vertebrate species. [source] Expression of non-signaling membrane-anchored death receptors protects murine livers in different models of hepatitis,,HEPATOLOGY, Issue 2 2006Delphyne Descamps Fas and tumor necrosis factor receptor 1 (TNFR1) are death receptors involved in various diseases such as hepatitis, sepsis, or graft rejection. Neutralizing antibodies to death ligands or soluble death receptors can inhibit cell death; however, they induce side effects because of their systemic actions. To specifically block death signaling to target cells, we created death domain,deficient (,DD) membrane-anchored receptors, delivered to the liver by either recombinant adenovirus or hydrodynamic pressure of nonviral recombinant plasmids. In anti-Fas antibody-induced fulminant hepatitis, mice expressing recombinant Fas-decoy receptors (Fas,DD) in their livers were completely protected against apoptosis and survived fulminant hepatitis. In T-cell,dependent concanavalin A,induced autoimmune hepatitis, Fas,DD antagonist expression prevented hepatocyte damage and mouse death. Finally, TNFR1,DD effectively protected mice against LPS-induced septic shock. In conclusion, such ,DD-decoy receptors act as dominant-negative receptors exerting local inhibition, while avoiding systemic neutralization of apoptosis ligands, and might have therapeutic potential in hepatitis. (HEPATOLOGY 2006;44:399,409.) [source] Caspase-8 in Apoptosis: The Beginning of "The End"?IUBMB LIFE, Issue 2 2000Marieke Kruidering Abstract Caspase-8 is a member of the cysteine proteases, which are implicated in apoptosis and cytokine processing. Like all caspases, caspase-8 is synthesized as an inactive single polypeptide chain zymogen procaspase and is activated by proteolytic cleavage, through either autoactivation after recruitment into a multimeric complex or trans-cleavage by other caspases. Thus, ligand binding-induced trimerization of death receptors results in recruitment of the receptor-specific adapter protein Fas-associated death domain (FADD), which then recruits caspase-8. Activated caspase-8 is known to propagate the apoptotic signal either by directly cleaving and activating downstream caspases or by cleaving the BH3 Bcl2-interacting protein, which leads to the release of cytochrome c from mitochondria, triggering activation of caspase-9 in a complex with dATP and Apaf-1. Activated caspase-9 then activates further "downstream caspases, " including caspase-8. Knockout data indicate that caspase-8 is required for killing induced by the death receptors Fas, tumor necrosis factor receptor 1, and death receptor 3. Moreover, caspase-8-/- mice die in utero as a result of defective development of heart muscle and display fewer hematopoietic progenitor cells, suggesting that the FADD/caspase-8 pathway is absolutely required for growth and development of specific cell types. [source] DR5-mediated DISC controls caspase-8 cleavage and initiation of apoptosis in human glioblastomasJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 6a 2010Anita C. Bellail Abstract To explore the molecular mechanisms by which glioblastomas are resistant to tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), we examined TRAIL signalling pathways in the tumours. TRAIL has four membrane-anchored receptors, death receptor 4/5 (DR4/5) and decoy receptor 1/2 (DcR1/2). Of these receptors, only DR5 was expressed consistently in glioblastoma cell lines and tumour tissues, ruling out the role of DcR1/2 in TRAIL resistance. Upon TRAIL binding, DR5 was homotrimerized and recruited Fas-associated death domain (FADD) and caspase-8 for the assembly of death-inducing signalling complex (DISC) in the lipid rafts of the plasma membrane. In the DISC, caspase-8 was cleaved and initiated apoptosis by cleaving downstream caspases in TRAIL-sensitive glioblastoma cells. In TRAIL-resistant cells, however, DR5-mediated DISC was modified by receptor-interacting protein (RIP), cellular FADD-like interleukin-1,-converting enzyme inhibitory protein (c-FLIP) and phosphoprotein enriched in diabetes or in astrocyte-15 (PED/PEA-15). This DISC modification occurred in the non-raft fractions of the plasma membrane and resulted in the inhibition of caspase-8 cleavage and activation of nuclear factor-,B (NF-,B). Treatment of resistant cells with parthenolide, an inhibitor of inhibitor of ,B (I-,B), eliminated TRAIL-induced NF-,B activity but not TRAIL resistance. In contrast, however, targeting of RIP, c-FLIP or PED/PEA-15 with small interfering RNA (siRNA) led to the redistribution of the DISC from non-rafts to lipid rafts and eliminated the inhibition of caspase-8 cleavage and thereby TRAIL resistance. Taken together, this study indicates that the DISC modification by RIP, c-FLIP and PED/PEA-15 is the most upstream event in TRAIL resistance in glioblastomas. [source] Expediting the Fmoc solid phase synthesis of long peptides through the application of dimethyloxazolidine dipeptidesJOURNAL OF PEPTIDE SCIENCE, Issue 1 2004Dr Peter White Abstract This paper describes the step-wise Fmoc solid phase synthesis of a 95-residue peptide related to FAS death domain. Attempts to prepare this peptide employing conventional amino acid building blocks failed. However, by the judicious use of dimethyloxazolidine dipeptides of serine and threonine, the peptide could be readily prepared in remarkable purity by applying single 1 h coupling reactions. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd. [source] c-Jun NH2 -terminal kinase-dependent fas activation contributes to etoposide-induced apoptosis in p53-mutated prostate cancer cellsTHE PROSTATE, Issue 4 2003Keiji Shimada Abstract Background The death receptor, Fas, has recently been demonstrated to contribute the chemotherapeutic agents-induced apoptosis, however, the detail mechanisms have yet to be fully understood, especially in prostate cancer cells. Methods PC-3 and DU145 stably transfected with dominant negative form of Fas-associated death domain (FADD) or specific kinase of c-Jun NH2 -terminal kinase (JNK) (mitogen-activated protein kinase kinase, MKK7) were selected in the presence of hygromycin B (Hyg B). Cell viability was examined by (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulphonyl)- 2H-tetrazolium, inner salt (MTS) assay or flowcytometric analysis using green fluorescent protein (GFP). Apoptosis was examined by DNA ladder, Western blotting analysis of cleaved caspases, or morphological analysis. The expression of Fas and JNK activation were investigated by Western blotting/flowcytometric analysis and in vitro kinase assay, respectively. Results Stimulation with etoposide significantly up-regulated Fas, and the death-inducing signaling complex (DISC) was formed in PC-3 and DU145. Stable transfection with dominant-negative FADD inhibited etoposide-induced apoptosis. In addition, stable transfection with dominant-negative MKK7, by which JNK activation was inhibited, canceled both the up-regulation of Fas and the formation of DISC by etoposide. Re-introduction of wild type p53 into PC-3 and DU145 completely suppressed these inhibitory effects. Conclusions These results suggest that, in p53-mutated prostate cancer, JNK-initiated Fas-mediated apoptotic signals may play an important role in chemosensitivity. Prostate 55: 265,280, 2003. © 2003 Wiley-Liss, Inc. [source] Somatic mutation of the death domain of TNF-R1 is rare in common cancersAPMIS, Issue 7 2009MIN SUNG KIM No abstract is available for this article. [source] Novel markers of inflammation identified in tumor necrosis factor receptor,associated periodic syndrome (TRAPS) by transcriptomic analysis of effects of TRAPS-associated tumor necrosis factor receptor type I mutations in an endothelial cell lineARTHRITIS & RHEUMATISM, Issue 1 2009Susana L. Rebelo Objective To analyze the effects of tumor necrosis factor receptor,associated periodic syndrome (TRAPS),associated mutant tumor necrosis factor receptor type I (TNFRI) expression in a cell type directly relevant to the inflammation in TRAPS, and to identify novel markers associated with mutant TNFRI expression. Methods Transcriptome analysis on 30,000 human genes was performed on SK-Hep-1 human endothelial cells transfected with either wild-type (WT) or TRAPS-associated mutant TNFRI. Quantitative reverse transcriptase,polymerase chain reaction and protein expression levels measured by enzyme-linked immunosorbent assay verified transcriptional changes for selected genes both in supernatants from cells expressing mutant TNFRI and in patient plasma. Results Cells expressing mutant TNFRI showed up-regulation of multiple proinflammatory genes relative to WT transfectants, including genes for pentraxin 3, granulocyte,macrophage colony-stimulating factor, granulocyte colony-stimulating factor, CCL2, and CCL5, which were also expressed as proteins. In addition, the expression of most of these markers was increased in the plasma and peripheral blood mononuclear cells from TRAPS patients relative to those from healthy controls. The cysteine mutations (C33Y and C52F), which are associated with a more severe clinical phenotype, induced more genes than the low-penetrance mutation R92Q, which is associated with a milder phenotype. The expression of most genes was induced by a death domain (DD),dependent mechanism, since they were not induced by expression of TNFRI mutants with an inactivated DD. Conclusion TRAPS-associated TNFRI mutants induce the expression of multiple genes encoding inflammatory molecules, cellular receptors, transcription factors, and regulators of apoptosis in endothelial cells that require the cytoplasmic signaling properties of the receptor. Different mutants have specific expression profiles, indicating mutation-specific effects. The expression of some of these markers was also elevated in samples from TRAPS patients. [source] | ||||||||||||||||