Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.22.56 (caspase-3)
 35,750 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Disintegrins, the snake venom-derived arginine-glycine-aspartic acid-containing peptides, have been demonstrated to inhibit angiogenesis through induction of endothelial cell apoptosis. However, it is not clear how a disintegrin causes endothelial apoptosis. In this study, we elucidated the action mechanism of disintegrin in causing endothelial apoptosis by using rhodostomin as a tool. We showed that cell detachment was observed at the early stage of rhodostomin treatment. It was initiated through the blockade by integrin alphanubeta3 and was accelerated by a mechanical stretch from neighboring cells. Both rhodostomin and poly(HEME) induced a higher percentage of cells at G2-M phase, the cleavage of beta-catenin and poly(ADP-ribose) polymerase during apoptosis, indicating that cell detachment is a prerequisite for rhodostomin-induced apoptosis. Moreover, pp125(FAK) phosphorylation and actin cytoskeleton were affected upon rhodostomin treatment. The activation of caspase-3 but not that of caspase-9 was detected after rhodostomin treatment. In addition, general caspase inhibitors inhibited the cleavage of beta-catenin and poly(ADP-ribose) polymerase, and DNA fragmentation, whereas they did not prevent cell shape change or detachment. According to these results, we concluded that disintegrin-induced endothelial apoptosis is a complex process, not merely caused by a blockade of endothelial integrin alphanubeta3 but also by an accompanied shape change and mechanical stretches among cells.
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PMID:Disintegrin causes proteolysis of beta-catenin and apoptosis of endothelial cells. Involvement of cell-cell and cell-ECM interactions in regulating cell viability. 1272

Caspase-3 is a cysteinyl protease that mediates apoptotic cell death. Its inhibition may have an important impact in the treatment of several degenerative diseases. Since P(1) aspartic acid is a required element of recognition for this enzyme, a library of capped aspartyl aldehydes was synthesized using solid-phase chemistry. The 5-bromonicotinamide derivative of the aspartic acid aldehyde was identified to be an inhibitor of caspase-3. Substitution at the 5-position of the pyridine ring and conversion of the aldehyde to ketones led to a series of potent inhibitors of caspase-3.
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PMID:Nicotinyl aspartyl ketones as inhibitors of caspase-3. 1279 21

The c-Jun N-terminal kinases (JNKs) are a subfamily of the mitogen-activated protein kinases (MAPKs). The JNKs are encoded by three separate genes (jnk1, jnk2, and jnk3), which are spliced alternatively to create 10 JNK isoforms that are either p46 or p54 in size. In this study, we found that the p52 form of JNK emerged in human leukemia MOLT-4 or U937 cells following X-irradiation or heat treatment. The accumulation of p52 coincided with the reduction of p54 JNK. On the other hand, the amounts of p46 JNK did not change by X-irradiation. Induction of the p52 form of JNK also paralleled the appearance of the active form of caspase-3 and was suppressed by a caspase-specific inhibitor, Ac-DEVD-CHO, but not by Ac-YVAD-CHO. In vitro cleavage assays indicated that recombinant human JNK1beta2 and JNK2beta2 were cleaved by caspase-3, and that the mutation of aspartic acid at position 413 of JNK1beta2 or 410 of JNK2beta2 to alanine abolished the cleavage. Altogether, our results demonstrated that p54 JNKs, at least JNK1beta2 and JNK2beta2, were new selective targets of caspases in JNK splicing variants, and suggested that the p52 form could serve as a marker of apoptosis.
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PMID:Caspase-mediated cleavage of JNK during stress-induced apoptosis. 1282 Nov 18

Apoptosis and necrosis are two distinct forms of cell death that can occur in response to different agents and stress conditions. In order to verify if the oxidative stress induced by dietary selenium and vitamin E deficiencies can lead muscle cells to apoptosis, one-day-old chicks were reared using diets differing in their vitamin E (0 or 10 IU/kg) and selenium (0 or 0.15 ppm) supplementation. Chick skeletal muscle tissue was obtained from 28-day-old animals and used to verify apoptosis occurrence based on caspase activity detection and DNA fragmentation. Antioxidant deficiency significantly increased caspase-like activity assessed by the hydrolysis of fluorogenic peptide substrates (Abz-peptidyl-EDDnp) at lambda exc = 320 nm and lambda em = 420 nm. Proteolytic activation was not accompanied by typical internucleosomal DNA fragmentation detected by field inversion gel electrophoresis. Although the general caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp(O-Me) fluoromethyl ketone (Z-VAD-fmk) (0 to 80 muM) did not block caspase-like activity when preincubated for 30 min with muscle homogenates, the hydrolyzed substrates presented the same cleavage profile in HPLC (at the aspartic acid residue) when incubated with the purified recombinant enzyme caspase-3. These data indicate that oxidative stress causes caspase-like activation in muscle cells and suggest that cell death associated with exudative diathesis (dietary deficiency of selenium and vitamin E) can follow the apoptotic pathway.
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PMID:Antioxidant dietary deficiency induces caspase activation in chick skeletal muscle cells. 1288 58

During rat estrous cycle, the endometrium proliferates in response to sex steroids and specific endometrial epithelial cells undergo apoptosis in absence of embryonic factors. The central executioner of apoptosis is a family of aspartic acid-specific cysteine proteases known as caspases. Smac/DIABLO is released from the mitochondria during apoptosis and its stimulation promotes caspases activation by neutralizing members of the inhibitor of apoptosis proteins (IAPs) family, such as X-linked inhibitor of apoptosis protein (XIAP). The aim of this study was to investigate the involvement of Smac/DIABLO and XIAP in the control of caspases activation in endometrium of cycling rats. Polyoestrus female rats were sacrificed at each stage of estrous cycle (diestrus, proestrus, estrus, and metestrus). Endometrial protein extracts were collected to perform Western Blot analysis. Alternatively, uterine horns were sectioned for immunohistochemistry (IHC). We and others showed previously the presence of apoptosis at estrus in rat uterine epithelium. In the present study, cleaved caspase-3, -6, and -7 fragments were detected at estrus. IHC confirmed that caspase-3 was present only in luminal and glandular epithelium at estrus. XIAP was highly expressed at estrus in both epithelial and stromal cells. In contrast, expression of Smac/DIABLO was elevated at diestrus, proestrus and metestrus but was minimal at estrus. Treatment of ovariectomized rats with 17beta-estradiol induced XIAP expression and inhibited Smac/DIABLO protein expression in the endometrium. Cleaved caspase-3, -6, and -7 fragments increased in endometrial protein extracts following 17beta-estradiol treatment. Expression of NF-kappaB and IkappaB proteins, and IkappaB phosphorylation status were detected in the endometrium but were not influenced by the estrous cycle. These findings suggest that Smac/DIABLO and XIAP are regulated differently and may play important roles in the regulation of endometrial cell fate. Moreover, this study confirms a key role for executioner caspases in the control of apoptotic processes at estrus in the rat uterus.
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PMID:Opposite regulation of XIAP and Smac/DIABLO in the rat endometrium in response to 17beta-estradiol at estrus. 1296 50

Although a number of cell adhesion proteins have been identified as caspase substrates, the potential role of differentiation-specific desmosomal cadherins during apoptosis has not been examined. Here, we demonstrate that UV-induced caspase cleavage of the human desmoglein 1 cytoplasmic tail results in distinct 17- and 140- kDa products, whereas metalloproteinase-dependent shedding of the extracellular adhesion domain generates a 75-kDa product. In vitro studies identify caspase-3 as the preferred enzyme that cleaves desmoglein 1 within its unique repeating unit domain at aspartic acid 888, part of a consensus sequence not conserved among the other desmosomal cadherins. Apoptotic processing leads to decreased cell surface expression of desmoglein 1 and re-localization of its C terminus diffusely throughout the cytoplasm over a time course comparable with the processing of other desmosomal proteins and cytoplasmic keratins. Importantly, whereas classic cadherins have been reported to promote cell survival, short hairpin RNA-mediated suppression of desmoglein 1 in differentiated keratinocytes protected cells from UV-induced apoptosis. Collectively, our results identify desmoglein 1 as a novel caspase and metalloproteinase substrate whose cleavage likely contributes to the dismantling of desmosomes during keratinocyte apoptosis and also reveal desmoglein 1 as a previously unrecognized regulator of apoptosis in keratinocytes.
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PMID:The differentiation-dependent desmosomal cadherin desmoglein 1 is a novel caspase-3 target that regulates apoptosis in keratinocytes. 1628 77

Several lines of evidence support a role for protease activation during apoptosis. Herein, we investigated the involvement of several members of the CASP (cysteine aspartic acid-specific protease; CED-3- or ICE-like protease) gene family in fodrin and actin cleavage using mouse ovarian cells and HeLa cells combined with immunoblot analysis. Hormone deprivation-induced apo-ptosis in granulosa cells of mouse antral follicles incubated for 24 h was attenuated by two specific peptide inhibitors of caspases, zVAD-FMK and zDEVD-FMK (50-500 microM), confirming that these enzymes are involved in this paradigm of cell death. Proteolysis of actin was not observed in follicles incubated in vitro while fodrin was cleaved to the 120 kDa fragment that accompanies apoptosis. Fodrin, but not actin, cleavage was also detected in HeLa cells treated with various apoptotic stimuli. These findings suggest that, in contrast to recent data, proteolysis of cytoplasmic actin may not be a component of the cell death cascade. To confirm and extend these data, total cell proteins collected from mouse ovaries or non-apoptotic HeLa cells were incubated without and with recombinant caspase-1 (ICE), caspase-2 (ICH-1) or caspase-3 (CPP32). Immunoblot analysis revealed that caspase-3, but not caspase-1 nor caspase-2, cleaved fodrin to a 120 kDa fragment, wheres both caspases-1 and -3 (but not caspase-2) cleaved actin. We conclude that CASP gene family members participate in granulosa cell apoptosis during ovarian follicular atresia, and that collapse of the granulosa cell cytoskeleton may result from caspase-3-catalyzed fodrin proteolysis. However, the discrepancy in the data obtained using intact cells (actin not cleaved) versus the cell-free extract assays (actin cleaved) raises concern over previous conclusions drawn related to the role of actin cleavage in apoptosis.
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PMID:Cleavage of cytoskeletal proteins by caspases during ovarian cell death: evidence that cell-free systems do not always mimic apoptotic events in intact cells. 1646 83

Caspases are cysteine proteases involved in the signalling cascades of programmed cell death in which caspase-3 plays a central role, since it propagates death signals from intrinsic and extrinsic stimuli to downstream targets. The atomic resolution (1.06 Angstroms) crystal structure of the caspase-3 DEVD-cmk complex reveals the structural basis for substrate selectivity in the S4 pocket. A low-barrier hydrogen bond is observed between the side-chains of the P4 inhibitor aspartic acid and Asp179 of the N-terminal tail of the symmetry related p12 subunit. Site-directed mutagenesis of Asp179 confirmed the significance of this residue in substrate recognition. In the 1.06 Angstroms crystal structure, a radiation damage induced rearrangement of the inhibitor methylketone moiety was observed. The carbon atom that in a substrate would represent the scissile peptide bond carbonyl carbon clearly shows a tetrahedral coordination and resembles the postulated tetrahedral intermediate of the acylation reaction.
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PMID:Extended substrate recognition in caspase-3 revealed by high resolution X-ray structure analysis. 1678 77

Programmed cell death (apoptosis) is a ubiquitous means utilized by multicellular organisms for elimination of unwanted cells during development and homeostasis. Dysregulated apoptosis is implicated in an array of clinical disorders including cancer, autoimmune diseases, neurodegenerative disorders, and ischemia. During programmed cell death, a series of proteases, known as caspases, with different specificities play crucial roles in the apoptotic process. Caspase-3, a group II cysteine aspartate protease, recognizes and cleaves substrates harboring the amino acid sequence aspartic acid-glutamic acid-valine-aspartic acid (DEVD), and it plays an important role in the terminal phase of apoptosis. Here we report the development of a novel imaging platform for sensing the activation of cellular proteases. A recombinant chimeric protein was constructed, composed of a cell-surface-targeted single-chain antibody (sFv) fused to a Golgi retention signal. The DEVD tetrapeptide sequence was included between the single-chain antibody and the Golgi retention signal as a caspase-3 protease cleavage site. When expressed in cultured cells this fusion protein was localized to Golgi bodies and was not detected on the cell surface. Induction of apoptosis resulted in cleavage of the fusion protein releasing the single-chain antibody from the Golgi retention signal in a caspase-dependent manner. As a result, in cells undergoing apoptosis the single-chain antibody was visualized at the cell surface by immunofluorescence microscopy. The expression of sFv on the surface of cells in a protease-dependent manner provides a unique opportunity for real-time imaging through the use of targeted nanoparticles. This methodology may provide for a multimodal noninvasive real-time imaging of apoptosis and a new opportunity for high-throughput screening of cell-death-modulating therapeutic agents.
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PMID:Imaging of proteolytic activity using a conditional cell surface receptor. 1695 27

To investigate the apoptosis effect of SARS coronavirus nucleocapsid protein on cultured cell lines and to explore the possible pathway of apoptosis. pCDNA3.1(-)/his-myc vector containing the SARS coronavirus nucleocapsid gene (N), matric gene (M), spike gene (S) were transfected into COS-1, Huh-7 and HepG2 cells. Apoptosis induced by SARS coronavirus N protein under starvation of serum of COS-1 cells was monitored by Annexin V and electron microscopy assays. Intracellular reactive oxygen species (ROS) and mitochondrial membrane potential (DeltaPsim) were determined by flow cytometric assay. Cytochrome C, cleaved caspase (cysteine aspartic acid protease)-3, 9, and poly (ADP-ribose) polymerase (PARP) were detected by Western blot. After removal of serum in COS-1 cells, we observed the loss of DeltaPsim, the increase of ROS and cytochrome C release into cytosol and subsequent activation of caspase-3 and PARP cleavage. The pan-caspase inhibitor z-VAD-fmk can block the activation of caspase 3, 9 and PARP cleavage. In conclusion, SARS coronavirus N protein can induce apoptosis of COS-1 cells by activating mitochondrial pathway. SARS coronavirus M, S protein can not induce apoptosis in COS-1, HepG2 and Huh-7 and SARS coronavirus N protein can not induce apoptosis in HepG2 and Huh-7 by methods used in this study.
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PMID:SARS-CoV nucleocapsid protein induced apoptosis of COS-1 mediated by the mitochondrial pathway. 1745 7


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