101
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Abstract
Ezrin links cortical actin filaments with the cell membrane, and has a critical role in many membrane-initiated events. Fas is directly associated with ezrin, but conflicting results have been reported for the involvement of ezrin in Fas-induced cell death. In this study we show that ezrin was associated with Fas in T cells before stimulation and was released shortly after Fas ligand (FasL) engagement. The knockdown of ezrin moderately increased Fas-triggered or tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-triggered cell death in normal T lymphocytes and in H9 cells, but had no effect on death receptor-induced apoptosis in type II cells, such as Jurkat and CEM. Expression of a dominant-negative form of ezrin also led to an increased Fas-induced apoptosis in H9 cells. Ezrin deficiency did not affect the internalization of Fas after Fas ligation. Instead, an enhanced formation of death-inducing signaling complex (DISC) was observed in H9 cells with ezrin knockdown, leading to accelerated caspase-8 activation. Together, our results suggest that ezrin has a negative role in the recruitment of Fas into signaling complexes in type I T cells. Loss of ezrin likely removes the constraint imposed by ezrin and facilitates the assembly of death receptor complex in T cells.
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102
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Functional analysis of the posttranslational modifications of the death receptor 6. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1793:1579-87. [DOI: 10.1016/j.bbamcr.2009.07.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2009] [Revised: 07/17/2009] [Accepted: 07/27/2009] [Indexed: 11/21/2022]
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103
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CD95 engagement mediates actin-independent and -dependent apoptotic signals. Cell Death Differ 2009; 16:1654-64. [DOI: 10.1038/cdd.2009.111] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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104
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Tardy C, Sabourdy F, Garcia V, Jalanko A, Therville N, Levade T, Andrieu-Abadie N. Palmitoyl protein thioesterase 1 modulates tumor necrosis factor alpha-induced apoptosis. BIOCHIMICA ET BIOPHYSICA ACTA 2009; 1793:1250-8. [PMID: 19345705 DOI: 10.1016/j.bbamcr.2009.03.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2008] [Revised: 03/19/2009] [Accepted: 03/23/2009] [Indexed: 11/22/2022]
Abstract
Induction of apoptosis by TNF has recently been shown to implicate proteases from lysosomal origin, the cathepsins. Here, we investigated the role in apoptosis of palmitoyl protein thioesterase 1 (PPT1), another lysosomal enzyme that depalmitoylates proteins. We show that transformed fibroblasts derived from patients with the infantile form of neuronal ceroid lipofuscinosis (INCL), a neurodegenerative disease due to deficient activity of PPT1, are partially resistant to TNF-induced cell death (57-75% cell viability vs. 15-30% for control fibroblasts). TNF-initiated proteolytic cleavage of caspase-8, Bid and caspase-3, as well as cytochrome c release was strongly attenuated in INCL fibroblasts as compared to control cells. Noteworthy, activation of p42/p44 mitogen-activated protein kinase and of transcription factor NF-kappaB by TNF, and induction of cell death by staurosporine or chemotherapeutic drugs in INCL cells were unaffected by PPT1 deficiency. Resistance to TNF-induced apoptosis was also observed in embryonic fibroblasts derived from Ppt1/Cln1-deficient mice but not from mice with a targeted deletion of Cln3 or Cln5. Finally, reconstitution of PPT1 activity in mutant cells was accompanied by resensitization to TNF-induced caspase activation and toxicity. These observations emphasize for the first time the role of PPT1 and, likely, protein depalmitoylation in the regulation of TNF-induced apoptosis.
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105
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Claudinon J, Gonnord P, Beslard E, Marchetti M, Mitchell K, Boularan C, Johannes L, Eid P, Lamaze C. Palmitoylation of interferon-alpha (IFN-alpha) receptor subunit IFNAR1 is required for the activation of Stat1 and Stat2 by IFN-alpha. J Biol Chem 2009; 284:24328-40. [PMID: 19561067 DOI: 10.1074/jbc.m109.021915] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Type I interferons (IFNs) bind IFNAR receptors and activate Jak kinases and Stat transcription factors to stimulate the transcription of genes downstream from IFN-stimulated response elements. In this study, we analyze the role of protein palmitoylation, a reversible post-translational lipid modification, in the functional properties of IFNAR. We report that pharmacological inhibition of protein palmitoylation results in severe defects of IFN receptor endocytosis and signaling. We generated mutants of the IFNAR1 subunit of the type I IFN receptor, in which each or both of the two cysteines present in the cytoplasmic domain are replaced by alanines. We show that cysteine 463 of IFNAR1, the more proximal of the two cytoplasmic cysteines, is palmitoylated. A thorough microscopic and biochemical analysis of the palmitoylation-deficient IFNAR1 mutant revealed that IFNAR1 palmitoylation is not required for receptor endocytosis, intracellular distribution, or stability at the cell surface. However, the lack of IFNAR1 palmitoylation affects selectively the activation of Stat2, which results in a lack of efficient Stat1 activation and nuclear translocation and IFN-alpha-activated gene transcription. Thus, receptor palmitoylation is a previously undescribed mechanism of regulating signaling activity by type I IFNs in the Jak/Stat pathway.
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Affiliation(s)
- Julie Claudinon
- Institut Curie, Centre de Recherche, Laboratoire Trafic, Signalisation et Ciblage Intracellulaires, 75248 Paris Cedex 05, France
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106
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Palmitoylation of the TRAIL receptor DR4 confers an efficient TRAIL-induced cell death signalling. Biochem J 2009; 419:185-92, 2 p following 192. [DOI: 10.1042/bj20081212] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
S-palmitoylation is a lipid modification that regulates membrane–protein association and influences protein trafficking, stability or aggregation, thus playing an important role in protein signalling. We previously demonstrated that the palmitoylation of Fas, one of the DD (death domain)-containing members of the TNFR [TNF (tumour necrosis factor) receptor] superfamily, is essential for the redistribution of this receptor into lipid rafts, an obligatory step for the death signal transmission. Here we investigate the requirement of protein palmitoylation in the activities of other DD-containing death receptors. We show that DR4 is palmitoylated, whereas DR5 and TNFR1 are not. Furthermore, DR4 palmitoylation is required for its raft localization and its ability to oligomerize, two essential features in TRAIL (TNF-related apoptosis-inducing ligand)-induced death signal transmission.
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107
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Symes J, Evangelou A, Ignatchenko A, Fleshner N, Kislinger T, Medin JA. Multidimensional protein identification technology analysis highlights mitoxantrone-induced expression modulations in the primary prostate cancer cell proteome. Proteomics Clin Appl 2009; 3:347-58. [PMID: 26238752 DOI: 10.1002/prca.200800102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2008] [Indexed: 11/06/2022]
Abstract
Chemotherapeutic agents as they are used today have limited effectiveness against prostate cancer, but may potentially be used in new combinations with more efficacious results. Mitoxantrone, used for palliation of prostate cancer, has recently been found by our group to improve the susceptibility of primary prostate cancer cells to killing through the Fas-mediated death pathway. Here we used a shotgun proteomics approach to first profile the entire prostate cancer proteome and then identify specific factors involved in this mitoxantrone response. Peptides derived from primary prostate cancer cells treated with or without 100 nM mitoxantrone were analyzed by multidimensional protein identification technology (MudPIT). Strict limits and data filtering hierarchies were applied to identify proteins with high confidence. We identified 1498 proteins belonging to the prostate cancer proteome, 83 of which were significantly upregulated and 27 of which were markedly downregulated following mitoxantrone treatment. These proteins perform diverse functions, including ceramide production, tumour suppression, and oxidative reduction. Detailed proteomic analyses of prostate cancer cells and their response to mitoxantrone will further our understanding of its mechanisms of action. Identification of proteins influenced by treatment with mitoxantrone or other compounds may lead to the development of more effective drug combinations against prostate cancer.
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Affiliation(s)
- Juliane Symes
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Andreas Evangelou
- Cancer Genomics and Proteomics, Ontario Cancer Institute, Toronto, Canada
| | - Alex Ignatchenko
- Cancer Genomics and Proteomics, Ontario Cancer Institute, Toronto, Canada
| | - Neil Fleshner
- Division of Urology, University Health Network, Toronto, Canada
| | - Thomas Kislinger
- Department of Medical Biophysics, University of Toronto, Toronto, Canada.,Cancer Genomics and Proteomics, Ontario Cancer Institute, Toronto, Canada
| | - Jeffrey A Medin
- Department of Medical Biophysics, University of Toronto, Toronto, Canada. .,Institute of Medical Sciences, University of Toronto, Toronto, Canada. .,Division of Stem Cell and Developmental Biology, Ontario Cancer Institute, Toronto, Canada.
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108
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Anathy V, Aesif SW, Guala AS, Havermans M, Reynaert NL, Ho YS, Budd RC, Janssen-Heininger YMW. Redox amplification of apoptosis by caspase-dependent cleavage of glutaredoxin 1 and S-glutathionylation of Fas. ACTA ACUST UNITED AC 2009; 184:241-52. [PMID: 19171757 PMCID: PMC2654302 DOI: 10.1083/jcb.200807019] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Reactive oxygen species (ROS) increase ligation of Fas (CD95), a receptor important for regulation of programmed cell death. Glutathionylation of reactive cysteines represents an oxidative modification that can be reversed by glutaredoxins (Grxs). The goal of this study was to determine whether Fas is redox regulated under physiological conditions. In this study, we demonstrate that stimulation with Fas ligand (FasL) induces S-glutathionylation of Fas at cysteine 294 independently of nicotinamide adenine dinucleotide phosphate reduced oxidase-induced ROS. Instead, Fas is S-glutathionylated after caspase-dependent degradation of Grx1, increasing subsequent caspase activation and apoptosis. Conversely, overexpression of Grx1 attenuates S-glutathionylation of Fas and partially protects against FasL-induced apoptosis. Redox-mediated Fas modification promotes its aggregation and recruitment into lipid rafts and enhances binding of FasL. As a result, death-inducing signaling complex formation is also increased, and subsequent activation of caspase-8 and -3 is augmented. These results define a novel redox-based mechanism to propagate Fas-dependent apoptosis.
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Affiliation(s)
- Vikas Anathy
- Department of Pathology, University of Vermont, Burlington, VT 05405, USA
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109
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Zhang S, Liu T, Liang H, Zhang H, Yan D, Wang N, Jiang X, Feng W, Wang J, Li P, Li Z. Lipid rafts uncouple surface expression of transmembrane TNF-alpha from its cytotoxicity associated with ICAM-1 clustering in Raji cells. Mol Immunol 2009; 46:1551-60. [PMID: 19203796 DOI: 10.1016/j.molimm.2009.01.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Accepted: 01/02/2009] [Indexed: 01/20/2023]
Abstract
Since transmembrane tumor necrosis factor-alpha (tmTNF-alpha) has been reported to have a palmitoylated site at Cys(-47), and therefore its functions may be linked to lipid raft membrane microdomains. The present study tested a hypothesis that lipid rafts may serve as a signaling platform to mediate the bioactivity of tmTNF-alpha. We found that destruction of lipid rafts with methyl-beta-cyclodextrin (MCD) in Raji cells almost completely blocked the cytotoxicity of tmTNF-alpha, as did an anti-TNF-alpha antibody. Although a proportion of tmTNF-alpha was colocated with lipid rafts, either the replacement of Cys at -47 by Ala, destructing its possible lipid rafts-attaching site or the displacement of its cytoplasmic domain by the C-terminal sequence (131-157) of caveolin-1, making all tmTNF-alpha target to lipid rafts, had no effect on tmTNF-alpha cytotoxicity. The data suggest that the cytotoxicity of tmTNF-alpha is not associated with its lipid rafts location. Unparallel to decreased cytotoxicity, moreover, MCD significantly increased tmTNF-alpha expression on the cell surface, and these increased tmTNF-alpha molecules were capable of binding to sTNFR1. To further explore the mechanism of lipid rafts-mediated cytotoxicity of tmTNF-alpha, we demonstrated that MCD led to a marked decrease in adhesion of Raji cells to T24 cells, which was due to dissociation of adhesion molecule ICAM-1 from lipid rafts. These results indicate that lipid rafts importantly participate in the cytotoxicity of tmTNF-alpha through ICAM-1 clustering and consequent enhancement of the cell-cell contact. The data suggest that lipid rafts are essential for the killing of tmTNF-alpha through the cell-cell contact mediated by ICAM-1. However, lipid rafts may limit exposure of tmTNF-alpha to the cell surface.
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Affiliation(s)
- Shu Zhang
- Department of Immunology, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, Hubei 430030, China
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110
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Abstract
Death receptors are members of the tumor necrosis factor receptor superfamily characterized by a cytoplasmic region known as the "death domain" that enables the receptors to initiate cytotoxic signals when engaged by cognate ligands. Binding to the ligand results in receptor aggregation and recruitment of adaptor proteins, which, in turn, initiates a proteolytic cascade by recruiting and activating initiator caspases 8 and 10. Death receptors were once thought to primarily induce cytotoxic signaling cascades. However, recent data indicate that they initiate multiple signaling pathways, unveiling a number of nonapoptosis-related functions, including regulation of cell proliferation and differentiation, chemokine production, inflammatory responses, and tumor-promoting activities. These noncytotoxic cascades are not simply a manifestation of inhibiting proapoptotic pathways but are intrinsically regulated by adaptor protein and receptor internalization processes. Insights into these various death receptor signaling pathways provide new therapeutic strategies targeting these receptors in pathophysiological processes.
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Affiliation(s)
- Maria Eugenia Guicciardi
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, 200 First St. SW, Rochester, MN 55905, USA
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111
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Schütze S, Schneider-Brachert W. Impact of TNF-R1 and CD95 internalization on apoptotic and antiapoptotic signaling. Results Probl Cell Differ 2009; 49:63-85. [PMID: 19132322 DOI: 10.1007/400_2008_23] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Internalization of cell surface receptors has long been regarded as a pure means to terminate signaling via receptor degradation. A growing body of information points to the fact that many internalized receptors are still in their active state and that signaling continues along the endocytic pathway. Thus endocytosis orchestrates cell signaling by coupling and integrating different cascades on the surface of endocytic vesicles to control the quality, duration, intensity, and distribution of signaling events. The death receptors tumor necrosis factor-receptor 1 (TNF-R1) and CD95 (Fas, APO-1) are known not only to signal for cell death via apoptosis but are also capable of inducing antiapoptotic signals via transcription factor NF-kappaB induction or activation of the proliferative mitogen-activated protein kinase (MAPK)/ERK (extracellular signal-regulated kinase) protein kinase cascades, resulting in cell protection and tissue regeneration. A clue to the understanding of these contradictory biological phenomena may arise from recent findings which reveal a regulatory role of receptor internalization and intracellular receptor trafficking in selectively transmitting signals, which lead either to apoptosis or to the survival of the cell. In this chapter, we discuss the dichotomy of pro- and antiapoptotic signaling of the death receptors TNF-R1 and CD95. First, we will address the role of lipid rafts and post-translational modifications of death receptors in regulating the formation of receptor complexes. Then, we will discuss the role of internalization in determining the fate of the receptors and subsequently the specificity of signaling events. We propose that fusion of internalized TNF-receptosomes with trans-Golgi vesicles should be recognized as a novel mechanism to transduce death signals along the endocytic route. Finally, the lessons learnt from the strategy of adenovirus to escape apoptosis by targeting death receptor internalization demonstrate the biological significance of TNF receptor compartmentalization for immunosurveillance.
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Affiliation(s)
- Stefan Schütze
- Institute of Immunology, University Hospital of Schleswig-Holstein, Campus Kiel, Michaelisstr. 5, D-24105, Kiel, Germany.
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112
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Ramaswamy M, Cleland SY, Cruz AC, Siegel RM. Many checkpoints on the road to cell death: regulation of Fas-FasL interactions and Fas signaling in peripheral immune responses. Results Probl Cell Differ 2009; 49:17-47. [PMID: 19132321 DOI: 10.1007/400_2008_24] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Interactions between the TNF-family receptor Fas (CD95) and Fas Ligand (FasL, CD178) can efficiently induce apoptosis and are critical for the maintenance of immunological self-tolerance. FasL is kept under strict control by transcriptional and posttranslational regulation. Surface FasL can be cleaved by metalloproteases, resulting in shed extracellular domains, and FasL can also traffic to secretory lysosomes. Each form of FasL has distinct biological functions. Fas is more ubiquitously expressed, but its apoptosis-inducing function is regulated by a number of mechanisms including submembrane localization, efficiency of receptor signaling complex assembly and activation, and bcl-2 family members in some circumstances. When apoptosis is not induced, Fas-FasL interactions can also trigger a number of activating and proinflammatory signals. Harnessing the apoptosis-inducing potential of Fas for therapy of cancer and autoimmune disease has been actively pursued, and despite a number of unexpected side-effects that result from manipulating Fas-FasL interactions, this remains a worthy goal.
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Affiliation(s)
- Madhu Ramaswamy
- Immunoregulation Unit, Autoimmunity Branch, NIAMS, National Institutes of Health, Bethesda MD 20892, USA
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113
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Engedal N, Auberger P, Blomhoff HK. Retinoic acid regulates Fas-induced apoptosis in Jurkat T cells: reversal of mitogen-mediated repression of Fas DISC assembly. J Leukoc Biol 2008; 85:469-80. [DOI: 10.1189/jlb.1107790] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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114
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Chakrabandhu K, Huault S, Hueber AO. Distinctive molecular signaling in triple-negative breast cancer cell death triggered by hexadecylphosphocholine (miltefosine). FEBS Lett 2008; 582:4176-84. [DOI: 10.1016/j.febslet.2008.11.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2008] [Revised: 10/27/2008] [Accepted: 11/14/2008] [Indexed: 11/27/2022]
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115
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Gonnord P, Delarasse C, Auger R, Benihoud K, Prigent M, Cuif MH, Lamaze C, Kanellopoulos JM. Palmitoylation of the P2X7 receptor, an ATP-gated channel, controls its expression and association with lipid rafts. FASEB J 2008; 23:795-805. [PMID: 18971257 DOI: 10.1096/fj.08-114637] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The P2X7 receptor (P2X7R) is an ATP-gated cationic channel expressed by hematopoietic, epithelial, and neuronal cells. Prolonged ATP exposure leads to the formation of a nonselective pore, which can result in cell death. We show that P2X7R is associated with detergent-resistant membranes (DRMs) in both transfected human embryonic kidney (HEK) cells and primary macrophages independently from ATP binding. The DRM association requires the posttranslational modification of P2X7R by palmitic acid. Treatment of cells with the palmitic acid analog 2-bromopalmitate as well as mutations of cysteine to alanine residues abolished P2X7R palmitoylation. Substitution of the 17 intracellular cysteines of P2X7R revealed that 4 regions of the carboxyl terminus domain are involved in palmitoylation. Palmitoylation-defective P2X7R mutants showed a dramatic decrease in cell surface expression because of their retention in the endoplasmic reticulum and proteolytic degradation. Taken together, our data demonstrate that P2X7R palmitoylation plays a critical role in its association with the lipid microdomains of the plasma membrane and in the regulation of its half-life.
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Affiliation(s)
- P Gonnord
- Institut de Biochimie et Biophysique Moléculaire et Cellulaire, CNRS UMR 8619, Université Paris Sud, F-91405 Orsay cedex, France
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116
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Hébert M, Potin S, Sebbagh M, Bertoglio J, Bréard J, Hamelin J. Rho-ROCK-Dependent Ezrin-Radixin-Moesin Phosphorylation Regulates Fas-Mediated Apoptosis in Jurkat Cells. THE JOURNAL OF IMMUNOLOGY 2008; 181:5963-73. [DOI: 10.4049/jimmunol.181.9.5963] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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117
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Patra SK, Szyf M. DNA methylation-mediated nucleosome dynamics and oncogenic Ras signaling: insights from FAS, FAS ligand and RASSF1A. FEBS J 2008; 275:5217-35. [PMID: 18803665 DOI: 10.1111/j.1742-4658.2008.06658.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Cytosine methylation at the 5-carbon position is the only known stable base modification found in the mammalian genome. The organization and modification of chromatin is a key factor in programming gene expression patterns. Recent findings suggest that DNA methylation at the junction of transcription initiation and elongation plays a critical role in suppression of transcription. This effect is mechanistically mediated by the state of chromatin modification. DNA methylation attracts binding of methyl-CpG-binding domain proteins that trigger repression of transcription, whereas DNA demethylation facilitates transcription activation. Understanding the rules that guide differential gene expression, as well as transcription dynamics and transcript abundance, has proven to be a taxing problem for molecular biologists and oncologists alike. The use of novel molecular modeling methods is providing exciting insights into the challenging problem of how methylation mediates chromatin dynamics. New data implicate lipid rafts as the coordinators of signals emanating from the cell membrane and are converging on the mechanisms linking DNA methylation and chromatin dynamics. This review focuses on some of these recent advances and uses lipid-raft-facilitated Ras signaling as a paradigm for understanding DNA methylation, chromatin dynamics and apoptosis.
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118
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He HT, Marguet D. T-cell antigen receptor triggering and lipid rafts: a matter of space and time scales. Talking Point on the involvement of lipid rafts in T-cell activation. EMBO Rep 2008; 9:525-30. [PMID: 18516087 DOI: 10.1038/embor.2008.78] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Accepted: 04/21/2008] [Indexed: 11/09/2022] Open
Abstract
T-cell antigen receptor triggering mechanisms and lipid rafts are of broad interest, but are also controversial topics. Here, we review some recent progress in these two research fields, which has been accomplished mostly in live cells and with the use of advanced technologies. We then discuss the potential relationship between membrane-domain organization and T-cell antigen receptor-triggering mechanisms. On the basis of the relevant experimental observations, we argue that the key to achieving a better understanding of both processes is the ability to monitor the molecular dynamics and interactions taking place in the membrane of T cells at a spatial scale of tens to hundreds of nanometres, with a subsecond-to-second temporal resolution.
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Affiliation(s)
- Hai-Tao He
- Centre d'Immunologie de Marseille-Luminy, Case 906, F13288 Marseille Cedex 09, France.
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119
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Ren J, Wen L, Gao X, Jin C, Xue Y, Yao X. CSS-Palm 2.0: an updated software for palmitoylation sites prediction. Protein Eng Des Sel 2008; 21:639-44. [PMID: 18753194 DOI: 10.1093/protein/gzn039] [Citation(s) in RCA: 425] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Protein palmitoylation is an essential post-translational lipid modification of proteins, and reversibly orchestrates a variety of cellular processes. Identification of palmitoylated proteins with their sites is the foundation for understanding molecular mechanisms and regulatory roles of palmitoylation. Contrasting to the labor-intensive and time-consuming experimental approaches, in silico prediction of palmitoylation sites has attracted much attention as a popular strategy. In this work, we updated our previous CSS-Palm into version 2.0. An updated clustering and scoring strategy (CSS) algorithm was employed with great improvement. The leave-one-out validation and 4-, 6-, 8- and 10-fold cross-validations were adopted to evaluate the prediction performance of CSS-Palm 2.0. Also, an additional new data set not included in training was used to test the robustness of CSS-Palm 2.0. By comparison, the performance of CSS-Palm was much better than previous tools. As an application, we performed a small-scale annotation of palmitoylated proteins in budding yeast. The online service and local packages of CSS-Palm 2.0 were freely available at: http://bioinformatics.lcd-ustc.org/css_palm.
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Affiliation(s)
- Jian Ren
- Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, University of Science & Technology of China, Hefei, Anhui 230027, China
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120
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Salikhova A, Wang L, Lanahan AA, Liu M, Simons M, Leenders WPJ, Mukhopadhyay D, Horowitz A. Vascular endothelial growth factor and semaphorin induce neuropilin-1 endocytosis via separate pathways. Circ Res 2008; 103:e71-9. [PMID: 18723443 DOI: 10.1161/circresaha.108.183327] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The neuropilin (Nrp)1 receptor is essential for both nervous and vascular system development. Nrp1 is unusually versatile, because it transmits both chemoattractive and repulsive signals in response to vascular endothelial growth factor (VEGF)-A and class 3 semaphorins, respectively. Both Nrp1 and VEGF receptor 2 undergo ligand-dependent endocytosis. We sought to establish the endocytic pathway of Nrp1 and to determine whether uptake is required for its signaling. Whereas Nrp1 underwent clathrin-dependent endocytosis in response to VEGFA(165) treatment, semaphorin 3C (sema3C) induced lipid raft-dependent endocytosis. The myosin VI PDZ (postsynaptic density 95, Disk large, Zona occludens-1) adaptor protein synectin was essential for Nrp1 trafficking. Sema3C failed to inhibit migration of synectin(-/-) endothelial cells, mirroring the lower migratory response of these cells to VEGFA(165). These results show that the endocytic pathway of Nrp1 is determined by its ligand and that the trafficking of Nrp1 is essential for its signaling.
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Affiliation(s)
- Anna Salikhova
- Angiogenesis Research Center, Dartmouth Medical School, Lebanon, NH 03756, USA
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121
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Maisse C, Rossin A, Cahuzac N, Paradisi A, Klein C, Haillot ML, Hérincs Z, Mehlen P, Hueber AO. Lipid raft localization and palmitoylation: Identification of two requirements for cell death induction by the tumor suppressors UNC5H. Exp Cell Res 2008; 314:2544-52. [DOI: 10.1016/j.yexcr.2008.06.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2007] [Revised: 06/02/2008] [Accepted: 06/03/2008] [Indexed: 12/27/2022]
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122
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Chakrabandhu K, Huault S, Garmy N, Fantini J, Stebe E, Mailfert S, Marguet D, Hueber AO. The extracellular glycosphingolipid-binding motif of Fas defines its internalization route, mode and outcome of signals upon activation by ligand. Cell Death Differ 2008; 15:1824-37. [DOI: 10.1038/cdd.2008.115] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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123
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Zaman SN, Resek ME, Robbins SM. Dual acylation and lipid raft association of Src-family protein tyrosine kinases are required for SDF-1/CXCL12-mediated chemotaxis in the Jurkat human T cell lymphoma cell line. J Leukoc Biol 2008; 84:1082-91. [PMID: 18632989 DOI: 10.1189/jlb.1007698] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Chemokines play pivotal roles in regulating a wide variety of biological processes by modulating cell migration and recruitment. Deregulation of chemokine signaling can alter cell recruitment, contributing to the pathogenic states associated with autoimmune disease, inflammatory disorders, and sepsis. During chemotaxis, lipid rafts and their resident signaling molecules have been demonstrated to partition to different parts of the cell. Herein, we investigated the role of lipid raft resident Src-family kinases (SFK) in stromal cell-derived factor 1/CXCL12-mediated chemotaxis. We have shown that Lck-deficient J.CaM 1.6 cells are defective in CXCL12-mediated chemotaxis in contrast to their parental counterpart, Jurkat cells. Ectopic expression of the SFK hematopoietic cell kinase (Hck) in J.CaM 1.6 cells reconstituted CXCL12 responsiveness. The requirement of lipid raft association of SFK was assessed using both isoforms of Hck: the dually acylated p59(Hck) isoform that is targeted to lipid rafts and the monoacylated p61(Hck) isoform that is nonraft-associated. We have shown using several gain and loss of acylation alleles that dual acylation of Hck was required for CXCL12-mediated chemotaxis in J.CaM 1.6 cells. These results highlight the importance of the unique microenvironment provided by lipid rafts and their specific contribution in providing specificity to CXCL12 signaling.
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124
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Bénéteau M, Pizon M, Chaigne-Delalande B, Daburon S, Moreau P, De Giorgi F, Ichas F, Rebillard A, Dimanche-Boitrel MT, Taupin JL, Moreau JF, Legembre P. Localization of Fas/CD95 into the lipid rafts on down-modulation of the phosphatidylinositol 3-kinase signaling pathway. Mol Cancer Res 2008; 6:604-13. [PMID: 18403639 DOI: 10.1158/1541-7786.mcr-07-0331] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Activation of the phosphatidylinositol 3-kinase (PI3K) signaling pathway is known to protect tumor cells from apoptosis and more specifically from the Fas-mediated apoptotic signal. The antitumoral agent edelfosine sensitizes leukemic cells to death by inducing the redistribution of the apoptotic receptor Fas into plasma membrane subdomains called lipid rafts. Herein, we show that inhibition of the PI3K signal by edelfosine triggers a Fas-mediated apoptotic signal independently of the Fas/FasL interaction. Furthermore, similarly to edelfosine, blockade of the PI3K activity, using specific inhibitors LY294002 and wortmannin, leads to the clustering of Fas whose supramolecular complex is colocalized within the lipid rafts. These findings indicate that the antitumoral agent edelfosine down-modulates the PI3K signal to sensitize tumor cells to death through the redistribution of Fas into large platform of membrane rafts.
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Affiliation(s)
- Marie Bénéteau
- Centre National de la Recherche Scientifique-Unite Mixte de Recherche 5164, 33076 Bordeaux, France
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125
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Epand RM. Proteins and cholesterol-rich domains. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2008; 1778:1576-82. [DOI: 10.1016/j.bbamem.2008.03.016] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Revised: 03/19/2008] [Accepted: 03/24/2008] [Indexed: 12/21/2022]
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126
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Abstract
T cell cytoarchitecture differs dramatically depending on whether the cell is circulating within the bloodstream, migrating through tissues, or interacting with antigen-presenting cells. The transition between these states requires important signaling-dependent changes in actin cytoskeletal dynamics. Recently, analysis of actin-regulatory proteins associated with T cell activation has provided new insights into how T cells control actin dynamics in response to external stimuli and how actin facilitates downstream signaling events and effector functions. Among the actin-regulatory proteins that have been identified are nucleation-promoting factors such as WASp, WAVE2, and HS1; severing proteins such as cofilin; motor proteins such as myosin II; and linker proteins such as ezrin and moesin. We review the current literature on how signaling pathways leading from diverse cell surface receptors regulate the coordinated activity of these and other actin-regulatory proteins and how these proteins control T cell function.
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Affiliation(s)
- Janis K Burkhardt
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia and University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
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127
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Regulation of TNFR1 and CD95 signalling by receptor compartmentalization. Nat Rev Mol Cell Biol 2008; 9:655-62. [PMID: 18545270 DOI: 10.1038/nrm2430] [Citation(s) in RCA: 212] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The death receptors tumour-necrosis factor receptor-1 (TNFR1) and CD95 (also known as FAS and APO-1) transduce signals that promote cell death by apoptosis. However, these receptors are also capable of inducing anti-apoptotic signals through the activation of the transcription factor nuclear factor-kappaB (NF-kappaB) or through activation of the proliferative mitogen-activated protein kinase (MAPK) cascade. Recent findings reveal a role for receptor internalization and endosomal trafficking in selectively transmitting the signals that lead either to apoptosis or to the survival of the cell.
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128
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Abstract
Death receptors induce apoptosis through either the Type I or II pathway. In Type I cells, the initiator caspase-8 directly activates effector caspases such as caspase-3, whereas in Type II cells, the death signal is amplified through mitochondria thereby activating effector caspases causing cell death. Recently, there have been advances in elucidating the early events in the CD95 signaling pathways and how post-translational modifications regulate CD95 signaling. This review will focus on recent insights into the mechanisms of the two different types of CD95 signaling pathways, and will introduce miRNAs as regulators of death receptor signaling.
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Affiliation(s)
- Sun-Mi Park
- The Ben May Department for Cancer Research, The University of Chicago, 924 E 57th Street, Chicago, IL 60637, Phone: 773-702-4728, FAX: 773-702-3701
| | - Marcus E. Peter
- The Ben May Department for Cancer Research, The University of Chicago, 924 E 57th Street, Chicago, IL 60637, Phone: 773-702-4728, FAX: 773-702-3701
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129
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Chapter Four Methods to Analyze the Palmitoylated CD95 High Molecular Weight Death‐Inducing Signaling Complex. Methods Enzymol 2008. [DOI: 10.1016/s0076-6879(08)01404-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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130
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Koncz G, Kerekes K, Chakrabandhu K, Hueber AO. Regulating Vav1 phosphorylation by the SHP-1 tyrosine phosphatase is a fine-tuning mechanism for the negative regulation of DISC formation and Fas-mediated cell death signaling. Cell Death Differ 2007; 15:494-503. [DOI: 10.1038/sj.cdd.4402282] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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131
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Patra SK. Dissecting lipid raft facilitated cell signaling pathways in cancer. Biochim Biophys Acta Rev Cancer 2007; 1785:182-206. [PMID: 18166162 DOI: 10.1016/j.bbcan.2007.11.002] [Citation(s) in RCA: 142] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2007] [Revised: 11/24/2007] [Accepted: 11/29/2007] [Indexed: 01/09/2023]
Abstract
Cancer is one of the most devastating disorders in our lives. Higher rate of proliferation than death of cells is one of the essential factors for development of cancer. The dynamicity of cell membrane plays some vital roles in cell survival and cell death, including protection, endocytosis, signaling, and increases in mechanical stability during cell division, as well as decrease of shear forces during separation of two cells after division, and cell separation from tissues for cancer metastasis. Within the membrane, there are specialized domains, known as lipid rafts. A raft can coordinate various signaling pathways. Recent data on the proteomics of lipid rafts/caveolae have highlighted the enigmatic role of various signaling proteins in cancer development. Analysis of these data of raft proteome from various tumors, cancer tissues, and cell lines cultured without and with therapeutic agents, as well as from model rafts revealed that there may be two subsets of raft assemblage in cell membrane. One subset of raft is enriched with cholesterol-sphingomyeline-ganglioside-cav-1/Src/EGFR (hereafter, "chol-raft") that is involved in normal cell signaling, and when dysregulated promotes cell transformation and tumor progression; another subset of raft is enriched with ceramide-sphingomyeline-ganglioside-FAS/Ezrin (hereafter, "cer-raft") that generally promotes apoptosis. In view of this, and to focus insight into the cancer cell physiology caused by the lipid rafts mediated signals and their receptors, and the downstream transmitters, either proliferative (for example, EGF and EGFR) or death-inducing (for example, FASL and FAS), and the precise roles of some therapeutic drugs and endogenous acid sphingomylenase in this scenario in in situ transformation of "chol-raft" into "cer-raft" are summarized and discussed in this contribution.
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Affiliation(s)
- Samir Kumar Patra
- Cancer Epigenetics Research, Kalyani (B-7/183), Nadia, West Bengal, India-741235.
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132
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Sharif-Askari E, Gaucher D, Halwani R, Ma J, Jao K, Abdallah A, Haddad EK, Sékaly RP. p56Lck tyrosine kinase enhances the assembly of death-inducing signaling complex during Fas-mediated apoptosis. J Biol Chem 2007; 282:36048-56. [PMID: 17932036 DOI: 10.1074/jbc.m706007200] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Although the death-inducing signaling complex (DISC) is rapidly assembled, several lines of evidence suggest that formation of this complex is not the first consequence of cell surface CD95 (Fas) stimulation but rather a later step in this process. Activation of Fas triggers a cascade of signaling events that culminate in cellular apoptosis. Tyrosine kinases are critical effectors in T cell activation. However, their functional involvement in death receptor-mediated apoptosis is unknown. Here, we used p56(Lck)-deficient cells to show that CD95-induced cell death is highly dependent on p56(Lck) activity and its localization within plasma membrane. We found that p56(Lck) acts upstream of the mitochondria; in the absence of p56(Lck), Bid cleavage and the release of cytochrome c were severely impaired. Moreover, p56(Lck)-deficient cells or cells expressing an inactive form of p56(Lck) displayed defective formation of the DISC post CD95 stimulation. In vivo reconstitution of thymocytes from p56(lck)-deficient mice, which are resistant to apoptosis, with p56(Lck) restored Fas-mediated cell death. Our results support a novel model whereby sensitivity to apoptosis is regulated through quantitative changes in the stoichiometry of DISC components triggered by p56(Lck) activation and localization.
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Affiliation(s)
- Ehssan Sharif-Askari
- Laboratoire d'Immunologie, Centre de Recherche CHUM Saint-Luc, Montréal H2X 1P1, Canada
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133
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Fernández M, Segura MF, Solé C, Colino A, Comella JX, Ceña V. Lifeguard/neuronal membrane protein 35 regulates Fas ligand-mediated apoptosis in neurons via microdomain recruitment. J Neurochem 2007; 103:190-203. [PMID: 17635665 DOI: 10.1111/j.1471-4159.2007.04767.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Fas ligand (FasL)-receptor system plays an essential role in regulating cell death in the developing nervous system, and it has been implicated in neurodegenerative and inflammatory responses in the CNS. Lifeguard (LFG) is a protein highly expressed in the hippocampus and the cerebellum, and it shows a particularly interesting regulation by being up-regulated during postnatal development and in the adult. We show that over-expression of LFG protected cortical neurons from FasL-induced apoptosis and decreased caspase-activation. Reduction of endogenous LFG expression by small interfering RNA sensitized cerebellar granular neurons to FasL-induced cell death and caspase-8 activation, and also increased sensitivity of cortical neurons. In differentiated cerebellar granular neurons, protection from FasL-induced cell death could be attributed exclusively to LFG and appears to be independent of FLICE inhibitor protein. Thus, LFG is an endogenous inhibitor of FasL-mediated neuronal death and it mediates the FasL resistance of CNS differentiated neurons. Finally, we also demonstrate that LFG is detected in lipid rafts microdomains, where it may interact with Fas receptor and regulate FasL-activated signaling pathways.
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Affiliation(s)
- Miriam Fernández
- Unidad Asociada Neurodeath, UCLM-CSIC, Departamento de Ciencias Médicas, Universidad de Castilla-La Mancha, Albacete, Spain
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134
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Abstract
CD95 is the quintessential death receptor and, when it is bound by ligand, cells undergo apoptosis. Recent evidence suggests, however, that CD95 mediates not only apoptosis but also diverse nonapoptotic functions depending on the tissue and the conditions.
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