scholarly journals Head Involution Defective(Hid)-triggered Apoptosis Requires Caspase-8 but Not FADD (Fas-associated Death Domain) and Is Regulated by Erk in Mammalian Cells

2002 ◽  
Vol 277 (38) ◽  
pp. 35097-35104 ◽  
Author(s):  
Jishy Varghese ◽  
Hadassah Sade ◽  
Peter Vandenabeele ◽  
Apurva Sarin
Keyword(s):  
Mammalian Cells ◽  
Caspase 8 ◽  
Death Domain

scholarly journals The flip side of FLIP

2004 ◽  
Vol 382 (2) ◽  
Author(s):  
Marcus E. PETER
Keyword(s):  
Mammalian Cells ◽  
Caspase 8 ◽  
Death Domain ◽  
Extrinsic Pathway ◽  
Inhibitory Protein ◽  
Apoptosis Pathway ◽  
Surface Receptors ◽  
Biochemical Journal ◽  
Initiator Caspases ◽  
Extrinsic Apoptosis

Two major pathways regulate apoptosis induction in mammalian cells. In the extrinsic pathway, apoptosis is induced through specialized surface receptors, whereas in the intrinsic pathway, apoptosis is induced from within the cell, mainly through activation of mitochondria. Shortly after the major mediators of the extrinsic apoptosis pathway, the initiator caspases-8 and -10, were identified, c-FLIP [FLICE-like inhibitory protein; FLICE is FADD (Fas-associated death domain protein)-like interleukin-1β-converting enzyme], a catalytically inactive caspase-8/-10 homologue, was reported. Whether this structure acts as an inhibitor or promoter of the extrinsic apoptosis pathway has been the subject of much debate. In this issue of the Biochemical Journal, Boatright et al. provide further evidence for the long splice form of c-FLIP (c-FLIPL) being an activator of caspase-8/-10, and demonstrate that the resulting heterodimer is enzymically active with a substrate specificity identical with that of the caspase-8 homodimer. Our understanding of the regulators of the extrinsic apoptosis signalling pathway biochemically may provide the means to design drugs to correct the imbalance between apoptosis and proliferation, as found in many diseases.

scholarly journals PCI-24781, a Novel Hydroxamic Acid HDAC Inhibitor, Exerts Cytotoxicity and Histone Alterations via Caspase-8 and FADD in Leukemia Cells

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Nilsa Rivera-Del Valle ◽  
Shan Gao ◽  
Claudia P. Miller ◽  
Joy Fulbright ◽  
Carolina Gonzales ◽  
...  
Keyword(s):  
Hdac Inhibitor ◽  
Hydroxamic Acid ◽  
Histone Deacetylase Inhibitors ◽  
Leukemia Cells ◽  
Ros Generation ◽  
Caspase 8 ◽  
Death Domain ◽  
Apoptosis Induction ◽  
Tumor Types ◽  
Insight Into

Histone deacetylase inhibitors (HDACi) have become a promising new avenue for cancer therapy, and many are currently in Phase I/II clinical trials for various tumor types. In the present study, we show that apoptosis induction and histone alterations by PCI-24781, a novel hydroxamic acid-based HDAC inhibitor, require caspase-8 and the adaptor molecule, Fas-associated death domain (FADD), in acute leukemia cells. PCI-24781 treatment also causes an increase in superoxide levels, which has been reported for other HDACi. However, an antioxidant does not reverse histone alterations caused by PCI-24781, indicating that ROS generation is likely downstream of the effects that PCI-24781 exerts on histone H3. Taken together, these results provide insight into the mechanism of apoptosis induction by PCI-24781 in leukemia by highlighting the roles of caspase-8, FADD and increased superoxide levels.

scholarly journals FADD (Fas-Associated Protein With Death Domain), Caspase-3, and Caspase-8 and Incidence of Ischemic Stroke

Stroke ◽  
2018 ◽  
Vol 49 (9) ◽  
pp. 2224-2226 ◽  
Author(s):  
Iram Faqir Muhammad ◽  
Yan Borné ◽  
Olle Melander ◽  
Marju Orho-Melander ◽  
Jan Nilsson ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Caspase 3 ◽  
Caspase 8 ◽  
Death Domain

scholarly journals Death Receptor-Induced Activation of Initiator Caspase 8 Is Antagonized by Serine/Threonine Kinase PAK4

2003 ◽  
Vol 23 (21) ◽  
pp. 7838-7848 ◽  
Author(s):  
Nerina Gnesutta ◽  
Audrey Minden
Keyword(s):  
Cell Death ◽  
Cell Survival ◽  
Intracellular Signaling ◽  
Death Receptor ◽  
Caspase 8 ◽  
Death Domain ◽  
Serine Threonine Kinase ◽  
Threonine Kinase ◽  
Different Types ◽  
Promote Cell Survival

ABSTRACT Normal cell growth requires a precisely controlled balance between cell death and survival. This involves activation of different types of intracellular signaling cascades within the cell. While some types of signaling proteins regulate apoptosis, or programmed cell death, other proteins within the cell can promote survival. The serine/threonine kinase PAK4 can protect cells from apoptosis in response to several different types of stimuli. As is the case for other members of the p21-activated kinase (PAK) family, one way that PAK4 may promote cell survival is by phosphorylating and thereby inhibiting the proapoptotic protein Bad. This leads in turn to the inhibition of effector caspases such as caspase 3. Here we show that in response to cytokines which activate death domain-containing receptors, such as the tumor necrosis factor and Fas receptors, PAK4 can inhibit the death signal by a different mechanism. Under these conditions, PAK4 inhibits apoptosis early in the caspase cascade, antagonizing the activation of initiator caspase 8. This inhibition, which does not require PAK4's kinase activity, may involve inhibition of caspase 8 recruitment to the death domain receptors. This role in regulating initiator caspases is an entirely novel role for the PAK proteins and suggests a new mechanism by which these proteins promote cell survival.

scholarly journals The lysosomal Rag-Ragulator complex licenses RIPK1– and caspase-8–mediated pyroptosis by Yersinia

Science ◽  
2021 ◽  
Vol 372 (6549) ◽  
pp. eabg0269
Author(s):  
Zengzhang Zheng ◽  
Wanyan Deng ◽  
Yang Bai ◽  
Rui Miao ◽  
Shenglin Mei ◽  
...  
Keyword(s):  
Cell Death ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Host Cells ◽  
Caspase 8 ◽  
Death Domain ◽  
Interacting Protein ◽  
A Genome ◽  
Infection Inhibition ◽  
Guanosine Triphosphatase

Host cells initiate cell death programs to limit pathogen infection. Inhibition of transforming growth factor–β–activated kinase 1 (TAK1) by pathogenic Yersinia in macrophages triggers receptor-interacting serine-threonine protein kinase 1 (RIPK1)–dependent caspase-8 cleavage of gasdermin D (GSDMD) and inflammatory cell death (pyroptosis). A genome-wide CRISPR screen to uncover mediators of caspase-8–dependent pyroptosis identified an unexpected role of the lysosomal folliculin (FLCN)–folliculin-interacting protein 2 (FNIP2)–Rag-Ragulator supercomplex, which regulates metabolic signaling and the mechanistic target of rapamycin complex 1 (mTORC1). In response to Yersinia infection, Fas-associated death domain (FADD), RIPK1, and caspase-8 were recruited to Rag-Ragulator, causing RIPK1 phosphorylation and caspase-8 activation. Pyroptosis activation depended on Rag guanosine triphosphatase activity and lysosomal tethering of Rag-Ragulator but not mTORC1. Thus, the lysosomal metabolic regulator Rag-Ragulator instructs the inflammatory response to Yersinia.

scholarly journals p38-mediated Regulation of an Fas-associated Death Domain Protein-independent Pathway Leading to Caspase-8 Activation during TGFβ-induced Apoptosis in Human Burkitt Lymphoma B Cells BL41

2001 ◽  
Vol 12 (10) ◽  
pp. 3139-3151 ◽  
Author(s):  
Nicolas Schrantz ◽  
Marie-Françoise Bourgeade ◽  
Shahul Mouhamad ◽  
Gérald Leca ◽  
Surendra Sharma ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Transforming Growth Factor ◽  
Dominant Negative ◽  
Dominant Negative Mutant ◽  
Caspase 8 ◽  
Death Domain ◽  
Apoptotic Pathway ◽  
Domain Protein

On binding to its receptor, transforming growth factor β (TGFβ) induces apoptosis in a variety of cells, including human B lymphocytes. We have previously reported that TGFβ-mediated apoptosis is caspase-dependent and associated with activation of caspase-3. We show here that caspase-8 inhibitors strongly decrease TGFβ-mediated apoptosis in BL41 Burkitt's lymphoma cells. These inhibitors act upstream of the mitochondria because they inhibited the loss of mitochondrial membrane potential observed in TGFβ-treated cells. TGFβ induced caspase-8 activation in these cells as shown by the cleavage of specific substrates, including Bid, and the appearance of cleaved fragments of caspase-8. Our data show that TGFβ induces an apoptotic pathway involving sequential caspase-8 activation, loss of mitochondrial membrane potential, and caspase-9 and -3 activation. Caspase-8 activation was Fas-associated death domain protein (FADD)-independent because cells expressing a dominant negative mutant of FADD were still sensitive to TGFβ-induced caspase-8 activation and apoptosis. This FADD-independent pathway of caspase-8 activation is regulated by p38. Indeed, TGFβ-induced activation of p38 and two different inhibitors specific for this mitogen-activated protein kinase pathway (SB203580 and PD169316) prevented TGFβ-mediated caspase-8 activation as well as the loss of mitochondrial membrane potential and apoptosis. Overall, our data show that p38 activation by TGFβ induced an apoptotic pathway via FADD-independent activation of caspase-8.

Interaction with Sug1 enables Ipaf ubiquitination leading to caspase 8 activation and cell death

2010 ◽  
Vol 427 (1) ◽  
pp. 91-104 ◽  
Author(s):  
Yatender Kumar ◽  
Vegesna Radha ◽  
Ghanshyam Swarup
Keyword(s):  
Cell Death ◽  
Mammalian Cells ◽  
Intramolecular Interaction ◽  
Dominant Negative ◽  
26S Proteasome ◽  
Caspase 8 ◽  
Interacting Protein ◽  
Caspase 1 ◽  
Lung Carcinoma Cells ◽  
Lrr Domain

Activation of initiator caspases is dependent on interacting proteins, and Ipaf [ICE (interleukin-1β-converting enzyme)-protease activating factor] {NLRC4 [NLR (Nod-like receptor) family CARD (caspase activation and recruitment domain)-containing 4]} an inflammasome component, is involved in caspase 1 activation and apoptosis. Investigating the mechanisms of Ipaf activation, we found that the C-terminal LRR (leucine-rich repeat) domain of Ipaf, through intramolecular interaction, negatively regulates its apoptosis-inducing function. In A549 lung carcinoma cells, expression of Ac-Ipaf (LRR-domain-deleted Ipaf) induced cell death that was dependent on caspase 8, but not on caspase 1. A yeast two-hybrid screen using Ac-Ipaf as bait identified human Sug1 (suppressor of gal 1), a component of the 26S proteasome, as an interacting protein. In mammalian cells Sug1 interacts and co-localizes with Ipaf. Sug1 binds to amino acids 91–253 of Ipaf, which is also the region that the LRR domain binds to. It potentiates cell death induced by Ipaf and Ac-Ipaf, and co-expression of Sug1 and Ipaf induces caspase-8-dependent cell death. Cellular complexes formed by Ipaf and Sug1 contain caspase 8. Expression of Ac-Ipaf or co-expression of Sug1 with Ipaf results in the formation of cytoplasmic aggregates and caspase 8 activation. Sug1 co-expression enabled modification of Ipaf by ubiquitination. Tagging ubiquitin molecules to Ipaf led to aggregate formation, enhanced caspase 8 interaction and activation, resulting in induction of cell death. Using RNAi (RNA interference) and dominant-negative approaches, we have shown that cell death induced by Ac-Ipaf expression or by treatment with TNF-α (tumour necrosis factor α) or doxorubicin is dependent on Sug1. Our results suggest a role for ubiquitination of Ipaf that is enabled by its interaction with Sug1, leading to caspase 8 activation and cell death.

scholarly journals Distinct Roles of the Antiapoptotic Effectors NleB and NleF from Enteropathogenic Escherichia coli

2017 ◽  
Vol 85 (4) ◽  
Author(s):  
Georgina L. Pollock ◽  
Clare V. L. Oates ◽  
Cristina Giogha ◽  
Tania Wong Fok Lung ◽  
Sze Ying Ong ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fas Ligand ◽  
Death Receptor ◽  
Effector Proteins ◽  
Host Cells ◽  
Caspase 8 ◽  
Death Domain ◽  
Content Type ◽  
Fas Signaling

ABSTRACT During infection, enteropathogenic Escherichia coli (EPEC) translocates effector proteins directly into the cytosol of infected enterocytes using a type III secretion system (T3SS). Once inside the host cell, these effector proteins subvert various immune signaling pathways, including death receptor-induced apoptosis. One such effector protein is the non-locus of enterocyte effacement (LEE)-encoded effector NleB1, which inhibits extrinsic apoptotic signaling via the FAS death receptor. NleB1 transfers a single N-acetylglucosamine (GlcNAc) residue to Arg117 in the death domain of Fas-associated protein with death domain (FADD) and inhibits FAS ligand (FasL)-stimulated caspase-8 cleavage. Another effector secreted by the T3SS is NleF. Previous studies have shown that NleF binds to and inhibits the activity of caspase-4, -8, and -9 in vitro. Here, we investigated a role for NleF in the inhibition of FAS signaling and apoptosis during EPEC infection. We show that NleF prevents the cleavage of caspase-8, caspase-3, and receptor-interacting serine/threonine protein kinase 1 (RIPK1) in response to FasL stimulation. When translocated into host cells by the T3SS or expressed ectopically, NleF also blocked FasL-induced cell death. Using the EPEC-like mouse pathogen Citrobacter rodentium, we found that NleB but not NleF contributed to colonization of mice in the intestine. Hence, despite their shared ability to block FasL/FAS signaling, NleB and NleF have distinct roles during infection.

scholarly journals LIGHT, a Member of the Tumor Necrosis Factor Ligand Superfamily, Prevents Tumor Necrosis Factor-α-mediated Human Primary Hepatocyte Apoptosis, but Not Fas-mediated Apoptosis

2002 ◽  
Vol 277 (51) ◽  
pp. 50054-50061 ◽  
Author(s):  
Hideki Matsui ◽  
Yukiko Hikichi ◽  
Isamu Tsuji ◽  
Takao Yamada ◽  
Yasushi Shintani
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Time Course ◽  
Caspase 3 ◽  
Nuclear Factor Κb ◽  
Caspase 8 ◽  
Death Domain ◽  
Human Primary Hepatocytes ◽  
Induced Apoptosis ◽  
Necrosis Factor

LIGHT is a member of tumor necrosis factor (TNF) superfamily, and its receptors have been identified as lymphotoxin-β receptor (LTβR) and the herpesvirus entry mediator (HVEM)/ATAR/TR2, both of which lack the cytoplasmic sequence termed the “death domain.” The present study has demonstrated that LIGHT inhibits TNFα-mediated apoptosis of human primary hepatocytes sensitized by actinomycin D (ActD), but not Fas- or TRAIL-mediated apoptosis. Furthermore, LIGHT does not prevent some cell lines such as HepG2 or HeLa from undergoing ActD/TNFα-induced apoptosis. This protective effect requires LIGHT pretreatment at least 3 h prior to ActD sensitization. LIGHT stimulates nuclear factor-κB (NF-κB)-dependent transcriptional activity in human hepatocytes like TNFα. The time course of NF-κB activation after LIGHT administration is similar to that of the pretreatment required for the anti-apoptotic effect of LIGHT. LIGHT inhibits caspase-3 processing on the apoptotic protease cascade in TNFα-mediated apoptosis but not Fas-mediated apoptosis. In addition, increased caspase-3 and caspase-8 activities in ActD/TNFα-treated cells are effectively blocked by LIGHT pretreatment. However, LIGHT does not change the expression of TNFRp55, TNFRp75, and Fas. These results indicate that LIGHT may act as an anti-apoptotic agent against TNFα-mediated liver injury by blocking the activation of both caspase-3 and caspase-8.

scholarly journals FLIPL induces caspase 8 activity in the absence of interdomain caspase 8 cleavage and alters substrate specificity

2011 ◽  
Vol 433 (3) ◽  
pp. 447-457 ◽  
Author(s):  
Cristina Pop ◽  
Andrew Oberst ◽  
Marcin Drag ◽  
Bram J. Van Raam ◽  
Stefan J. Riedl ◽  
...  
Keyword(s):  
Catalytic Domain ◽  
Functional Divergence ◽  
Caspase 8 ◽  
Death Domain ◽  
Extrinsic Pathway ◽  
Inhibitory Protein ◽  
Developmental Abnormalities ◽  
Developmental Role ◽  
Apoptotic Pathways

Caspase 8 is an initiator caspase that is activated by death receptors to initiate the extrinsic pathway of apoptosis. Caspase 8 activation involves dimerization and subsequent interdomain autoprocessing of caspase 8 zymogens, and recently published work has established that elimination of the autoprocessing site of caspase 8 abrogates its pro-apoptotic function while leaving its proliferative function intact. The observation that the developmental abnormalities of caspase 8-deficient mice are shared by mice lacking the dimerization adapter FADD (Fas-associated death domain) or the caspase paralogue FLIPL [FLICE (FADD-like interleukin 1β-converting enzyme)-inhibitory protein, long form] has led to the hypothesis that FADD-dependent formation of heterodimers between caspase 8 and FLIPL could mediate the developmental role of caspase 8. In the present study, using an inducible dimerization system we demonstrate that cleavage of the catalytic domain of caspase 8 is crucial for its activity in the context of activation by homodimerization. However, we find that use of FLIPL as a partner for caspase 8 in dimerization-induced activation rescues the requirement for intersubunit linker proteolysis in both protomers. Moreover, before processing, caspase 8 in complex with FLIPL does not generate a fully active enzyme, but an attenuated species able to process only selected natural substrates. Based on these results we propose a mechanism of caspase 8 activation by dimerization in the presence of FLIPL, as well as a mechanism of caspase 8 functional divergence in apoptotic and non-apoptotic pathways.

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