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Query: UNIPROT:P42574 (
caspase-3
)
45,978
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Apoptotic cell suicide initiated by ligation of CD95 (Fas/APO-1) occurs through recruitment, oligomerization and autocatalytic activation of the cysteine protease, caspase-8 (MACH, FLICE, Mch5). An endogenous mammalian regulator of this process, named Usurpin, has been identified (aliases for Usurpin include CASH, Casper, CLARP, FLAME-1, FLIP, I-FLICE and MRIT). This protein is ubiquitously expressed and exists as at least three isoforms arising by alternative mRNA splicing. The Usurpin gene is comprised of 13 exons and is clustered within approximately 200 Kb with the caspase-8 and -10 genes on human chromosome 2q33-34. The Usurpin polypeptide has features in common with pro-caspase-8 and -10, including tandem 'death effector domains' on the N-terminus of a large subunit/small subunit caspase-like domain, but it lacks key residues that are necessary for caspase proteolytic activity, including the
His
and Cys which form the catalytic substrates diad, and residues that stabilize the P1 aspartic acid in substrates. Retro-mutation of these residues to functional caspase counterparts failed to restore proteolytic activity, indicating that other determinants also ensure the absence of catalytic potential. Usurpin heterodimerized with pro-caspase-8 in vitro and precluded pro-caspase-8 recruitment by the FADD/MORT1 adapter protein. Cell death induced by CD95 (Fas/APO-1) ligation was attenuated in cells transfected with Usurpin. In vivo, a Usurpin deficit was found in cardiac infarcts where TUNEL-positive myocytes and active
caspase-3
expression were prominent following ischemia/reperfusion injury. In contrast, abundant Usurpin expression (and a
caspase-3
deficit) occurred in surrounding unaffected cardiac tissue, suggesting reciprocal regulation of these pro- and anti-apoptotic molecules in vivo. Usurpin thus appears to be an endogenous modulator of apoptosis sensitivity in mammalian cells, including the susceptibility of cardiac myocytes to apoptotic death following ischemia/ reperfusion injury.
...
PMID:Cell death attenuation by 'Usurpin', a mammalian DED-caspase homologue that precludes caspase-8 recruitment and activation by the CD-95 (Fas, APO-1) receptor complex. 1020 Apr 73
Many anticancer agents are known to induce apoptosis in cultured cells, but human solid tumor cells are often resistant to apoptosis induction. Human pancreatic adenocarcinoma AsPC-1 cells were found to be resistant to apoptosis. So, we screened microbial culture filtrates and synthetic chemicals for their ability to induce apoptosis in AsPC-1 cells. Polyoxypeptin A was isolated from a Streptomyces culture broth as a potent inducer of apoptosis. Its cyclic hexadepsipeptide structure contains a simple but hitherto unreported amino acid, (2S,3R)-3-hydroxy-3-methylproline. Polyoxypeptin A induced early cell death, apoptotic morphology, and internucleosomal DNA fragmentation in AsPC-1 cells at low concentrations. Polyoxypeptin A can induce
caspase 3
activation in human T cell leukemia Jurkat cells but not in AsPC-1 cells. The mechanism of apoptosis in AsPC-1 cells has not been elucidated yet. Less toxic derivatives of polyoxypeptin A are being prepared. A macrocyclic lactam called BE-14106 was also isolated from Streptomyces as an inducer of apoptosis in AsPC-1 cells.
Histidine
-pyridine-
histidine
-3 (HPH-3) is an oxygen-activating ligand derived from the structure of bleomycin, and it also induced apoptosis in AsPC-1 cells. Induction of apoptosis by HPH-3 was inhibited by zinc and copper ions, indicating that chelation with ferrous ion is responsible for induction of apoptosis, as is chelation by bleomycin to cleave DNA. Bleomycin A2 and its portion having no DNA-binding region, glycopeptide-3(GP-3), did not induce apoptosis in AsPC-1 cells. Thus, among the actions of bleomycin-related compounds, the induction of apoptosis is a unique characteristic of HPH-3.
...
PMID:Screening for inducers of apoptosis in apoptosis-resistant human carcinoma cells. 1047 Mar 71
4-Hydroxynonenal (HNE), a diffusible product of lipid peroxidation, has been suggested to be a key mediator of oxidative stress-induced cell death. In this study, we partially characterized the mechanism of HNE-mediated cytotoxicity. Incubation of human T lymphoma Jurkat cells with 20-50 microM HNE led to cell death accompanied by DNA fragmentation. Western blot analysis showed that HNE-treatment induced time- and dose-dependent activation of caspase-8, caspase-9 and
caspase-3
. HNE-induced
caspase-3
processing was confirmed by a flow cytometric demonstration of increased catalytic activity on the substrate peptide. HNE treatment also led to remarkable cleavage of poly(ADP-ribose) polymerase (PARP), which was prevented by pretreatment of cells with DEVD-FMK as a
caspase-3
inhibitor. The HNE-mediated activation of caspases, cleavage of PARP and DNA fragmentation were blocked by antioxidants cysteine, N-acety-L-cysteine and dithiothreitol, but not by two other HNE-reactive amino acids lysine and
histidine
, or by cystine, the oxidized form of cysteine. HNE rapidly decreased levels of intracellular reduced glutathione (GSH) and its oxidized form GSSG, and these were also attenuated by the reductants. Coincubation of Jurkat cells with a blocking anti-Fas antibody prevented Fas-induced but not HNE-induced activation of
caspase-3
. HNE also activated
caspase-3
in K562 cells that do not express functional Fas. Our results thereby demonstrate that HNE triggers oxidative stress-linked apoptotic cell death through activation of the caspase cascade. The results also suggest a possible mechanism involving a direct scavenge of intracellular GSH by HNE.
...
PMID:4-hydroxynonenal induces a cellular redox status-related activation of the caspase cascade for apoptotic cell death. 1065 56
Apoptosis, or programmed cell death, plays a central role in the development and homeostasis of an organism. The breakdown of cellular proteins in apoptosis is mediated by caspases, which comprise a highly conserved family of cysteine proteases with specificity for aspartic acid residues at the P1 positions of their substrates. Multiple lines of evidence show that caspase-9 is critical for an apoptosis pathway mediated via the mitochondria. In this study, the three-dimensional structure of the catalytic domain of caspase-9 and its interaction with the inhibitor acetyl-Asp-Val-Ala-Asp fluoromethyl ketone (Ac-DVAD-fmk) have been predicted by a segment matching modeling procedure. As expected, the predicted caspase-9 structure shows both a high similarity in the overall folding topology and remarkable differences in the surface loop regions as compared to other caspase family members such as caspase-1, -3 and -8, for which crystal structures have been determined. This kind of comparative analysis reflects the convergence-divergence duality among the caspases. Moreover, some subtle differences have been observed between caspase-9 and
caspase-3
in the subsite contacts with the covalently linked inhibitor Ac-DVAD-fmk. Based on the X-ray structural analysis of caspase-8, a main chain carbonyl oxygen appears to be involved in a catalytic triad with the active site Cys and
His
residues. The corresponding carbonyl oxygen in caspase-9, together with other expected features of the catalytic apparatus, appears in our model. The predicted structure of caspase-9 can serve as a reference for subsite analysis relative to rational design of highly selective caspase inhibitors for therapeutic application.
...
PMID:Prediction of the tertiary structure of a caspase-9/inhibitor complex. 1074 77
Calcium overload is suggested to play a fundamental role in the process of rod apoptosis in chemical-induced and inherited retinal degenerations. However, this hypothesis has not been tested directly. We developed an in vitro model utilizing isolated rat retinas to determine the mechanisms underlying Ca(2+)- and/or Pb(2+)-induced retinal degeneration. Confocal microscopy, histological, and biochemical studies established that the elevated [Ca(2+)] and/or [Pb(2+)] were localized to photoreceptors and produced rod-selective apoptosis. Ca(2+) and/or Pb(2+) induced mitochondrial depolarization, swelling, and cytochrome c release. Subsequently caspase-9 and
caspase-3
were sequentially activated. Caspase-7 and caspase-8 were not activated. The effects of Ca(2+) and Pb(2+) were additive and blocked completely by the mitochondrial permeability transition pore (PTP) inhibitor cyclosporin A, whereas the calcineurin inhibitor FK506 had no effect. The caspase inhibitors carbobenzoxy-Leu-Glu-
His
-Asp-CH(2)F and carbobenzoxy-Asp-Glu-Val-Asp-CH(2)F, but not carbobenzoxy-Ile-Glu-Thr-Asp-CH(2)F, differentially blocked post-mitochondrial events. The levels of reduced and oxidized glutathione and pyridine nucleotides in rods were unchanged. Our results demonstrate that rod mitochondria are the target site for Ca(2+) and Pb(2+). Moreover, they suggest that Ca(2+) and Pb(2+) bind to the internal metal (Me(2+)) binding site of the PTP and subsequently open the PTP, which initiates the cytochrome c-caspase cascade of apoptosis in rods.
...
PMID:Lead and calcium produce rod photoreceptor cell apoptosis by opening the mitochondrial permeability transition pore. 1076 53
The inhibitor of apoptosis proteins (IAPs) regulate the caspase family of cysteine proteases, which play an important role in the execution of programmed cell death. Human X-linked inhibitor of apoptosis protein (XIAP) is a potent inhibitor of caspases-3, -7, and -9. Here we show that the Bir3 domain is the minimal region of XIAP that is needed for potent caspase-9 inhibition. The three-dimensional structure of the Bir3 domain of XIAP, determined by NMR spectroscopy, resembles a classical zinc finger and consists of five alpha-helices, a three-stranded beta-sheet, and a zinc atom chelated to three cysteines and one
histidine
. The structure of the Bir3 domain is similar to that of the Bir2 domain of XIAP but differs from the previously determined structure of the Bir3 domain of MIHB. Based on site-directed mutagenesis, we have identified the regions of the Bir3 domain of XIAP that are important for inhibiting caspase-9. Despite the structural similarities of the Bir2 and Bir3 domain of XIAP, a different set of residues were found to be critical for inhibiting the individual caspases. These results suggest that XIAP inhibits
caspase-3
and caspase-9 in a different manner.
...
PMID:NMR structure and mutagenesis of the third Bir domain of the inhibitor of apoptosis protein XIAP. 1093 9
There is increasing evidence suggesting that chondrocyte death may contribute to the progression of osteoarthritis (OA). This study focused on the characterization of signaling cascade during NO-induced cell death in human OA chondrocytes. The NO generator, sodium nitroprusside (SNP), promoted chondrocyte death in association with DNA fragmentation,
caspase-3
activation, and down-regulation of Bcl-2. Both
caspase-3
inhibitor Z-Asp(OCH3)-Glu(OCH3)-Val-Asp(OCH3)-CH2F and caspase-9 inhibitor Z-Leu-Glu(OCH3)-
His
-Asp(OCH3)-CH2F prevented the chondrocyte death. Blocking the mitogen-activated protein kinase pathway by the mitogen-activated protein kinase kinase 1/2 inhibitor PD98059 or p38 kinase inhibitor SB202190 also inhibited the SNP-mediated cell death, suggesting possible requirements of both extracellular signal-related protein kinase 1/2 and p38 kinase for the NO-induced cell death. Furthermore, the selective inhibition of cyclooxygenase (COX)-2 by NS-398 or the inhibition of COX-1/COX-2 by indomethacin blocked the SNP-induced cell death. The chondrocyte death induced by SNP was associated with an overexpression of COX-2 protein (as determined by Western blotting) and an increase in PGE2 release. PD98059 and SB202190, but neither Z-DEVD FMK nor Z-LEHD FMK completely inhibited the SNP-mediated PGE2 production. Analysis of interactions between PGE2 and the cell death showed that PGE2 enhanced the SNP-mediated cell death, whereas PGE2 alone did not induce the chondrocyte death. These data indicate that NO-induced chondrocyte death signaling includes PGE2 production via COX-2 induction and suggest that both extracellular signal-related protein kinase 1/2 and p38 kinase pathways are upstream signaling of the PGE2 production. The results also demonstrate that exogenous PGE2 may sensitize human OA chondrocytes to the cell death induced by NO.
...
PMID:The induction of cell death in human osteoarthritis chondrocytes by nitric oxide is related to the production of prostaglandin E2 via the induction of cyclooxygenase-2. 1097 59
Photodynamic treatment (PDT) elicits diverse cellular responses and can also cause apoptosis. In the present study the cascade of signalling events involved in PDT-induced apoptosis was investigated using Rose Bengal (RB) as the photosensitizer, and human epidermal carcinoma A431 cells as the cell model. We show that a 36-kDa kinase detected by an in-gel kinase assay is markedly activated during PDT-triggered apoptosis. Immunoblot analysis revealed that this 36-kDa kinase represents the C-terminal catalytic fragment of p21-activated kinase (PAK)2. Generation of this active fragment of PAK2 is mediated by the caspase family of proteases, which are activated by PDT. The specific caspase inhibitors (acetyl-Asp-Glu-Val-Asp-aldehyde and acetyl-Tyr-Val-Ala-Asp-chloromethylketone) block the PDT-induced
caspase-3
activation and subsequent PAK2 cleavage/activation, indicating a major role for the caspase family proteases in PDT-induced apoptosis. Both PDT-induced
caspase-3
activation and PAK2 cleavage/activation can be inhibited by the singlet oxygen scavengers, L-
histidine
and alpha-tocopherol, but not the hydroxyl radical scavenger, mannitol, demonstrating that singlet oxygen is an immediate early-apoptotic signal generated by PDT. In addition, PDT can induce a two-stage activation of the c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) in A431 cells; the early-stage JNK activation is singlet oxygen-dependent, whereas the late-stage JNK activation is mediated by the singlet oxygen-triggered caspase activation. Experiments using anti-sense oligonucleotides against JNK1 and PAK2 further show that during PDT-induced apoptosis the early-stage JNK activation is required for caspase activation, and that the late-stage JNK activation is regulated by the caspase-mediated cleavage/activation of PAK2. Collectively, a model for the PDT-triggered apoptotic signalling cascade with RB is proposed, which involves singlet oxygen, JNK,
caspase-3
and PAK2, sequentially.
...
PMID:Apoptotic signalling cascade in photosensitized human epidermal carcinoma A431 cells: involvement of singlet oxygen, c-Jun N-terminal kinase, caspase-3 and p21-activated kinase 2. 1099 65
Photodynamic therapy (PDT), utilizing a photosensitizer and visible light, causes localized oxidative damage. With the mitochondrial photosensitizer Pc 4, PDT induces apoptosis, yet its molecular targets are not known. Here, the anti-apoptotic protein Bcl-2 is shown to be highly sensitive to PDT, as judged on Western blots by the disappearance of anti-Bcl-2-reactive material from the position of the native 26 kDa protein. The loss of Bcl-2 was PDT dose dependent and was observed for both endogenous and overexpressed Bcl-2 in several cell lines, immediately after PDT, and with chilled cells. It was accompanied by a trace of a 23-kDa cleavage product as well as high-molecular weight products that may result from photochemical crosslinking. PDT-induced Bcl-2 loss occurred in MCF-7 cells that do not express
caspase-3
or in the presence of protease inhibitors, but was prevented, along with the induction of apoptosis, by the singlet oxygen scavenger L-
histidine
. Loss of FLAG-Bcl-2 was observed with both anti-FLAG and anti-Bcl-2 antibodies, indicating loss of native protein rather than simple BCL-2-epitope destruction. Photochemical damage was not observed in Bcl-x(L), Bax, Bad, the voltage-dependent anion channel, or the adenine nucleotide translocator. Therefore, Bcl-2 is one target of PDT with Pc 4, and PDT damage to Bcl-2 contributes to its efficient induction of apoptosis.
...
PMID:Photochemical destruction of the Bcl-2 oncoprotein during photodynamic therapy with the phthalocyanine photosensitizer Pc 4. 1142 92
A conjugate of doxorubicin and glutathione via glutaraldehyde (GSH-DXR) inhibited glutathione S-transferase (GST) activity of rat hepatoma AH66 cells, and treatment of the cells with GSH-DXR induced
caspase-3
activation and DNA fragmentation. After treatment of AH66 cells with 0.1 microM GSH-DXR, GST-P (placental type of rat GST isozymes) mRNA and its protein increased transiently and then decreased thereafter compared with the levels in nontreated cells.
Caspase-3
activation and DNA fragmentation were induced following the suppression of GST-P expression by treatment with GSH-DXR. When the cells were treated with 100 microM ethacrynic acid (ECA), an inhibitor of GST, DNA fragmentation and
caspase-3
activation were observed. In contrast, treatment of AH66 cells with a low concentration of ECA (1 microM) that showed little inhibition of GST activity induced slight, but significantly enhanced expression and activity of GST-P, and consequent prevention of DXR- and GSH-DXR-induced DNA fragmentation. Overexpression of GST-pi (placental type of human GST isozymes) by transfection of GST-pi sense cDNA into AH66 cells decreased sensitivities to DXR and GSH-DXR, and the suppression of GST-P by transfection of the antisense cDNA into the cells increased drug sensitivity. On the other hand, there was little change in drug sensitivity caused by overexpression of site-directedly mutated GST-P in which the active-site residue Tyr39 was replaced with
His
(W39H) or the substrate-binding site residue Cys48 was replaced with Ser (C48S) by transfection of those cDNAs into AH66 cells. These results suggested that the suppression of GST-P in AH66 cells treated with GSH-DXR must play an important role in the induction of apoptosis.
...
PMID:Suppression of GST-P by treatment with glutathione-doxorubicin conjugate induces potent apoptosis in rat hepatoma cells. 1166 94
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