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Wrońska AK, Kaczmarek A, Kazek M, Boguś MI. Infection of Galleria mellonella (Lepidoptera) Larvae With the Entomopathogenic Fungus Conidiobolus coronatus (Entomophthorales) Induces Apoptosis of Hemocytes and Affects the Concentration of Eicosanoids in the Hemolymph. Front Physiol 2022; 12:774086. [PMID: 35069239 PMCID: PMC8769874 DOI: 10.3389/fphys.2021.774086] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 11/03/2021] [Indexed: 01/11/2023] Open
Abstract
Apoptosis and autophagy, the mechanisms of programmed cell death, play critical roles in physiological and pathological processes in both vertebrates and invertebrates. Apoptosis is also known to play an important role in the immune response, particularly in the context of entomopathogenic infection. Of the factors influencing the apoptotic process during infection, two of the lesser known groups are caspases and eicosanoids. The aim of this study was to determine whether infection by the entomopathogenic soil fungus Conidiobolus coronatus is associated with apoptosis and changes in caspase activity in the hemocytes of Galleria mellonella larvae, and to confirm whether fungal infection may affect eicosanoid levels in the host. Larvae were exposed for 24 h to fully grown and sporulating fungus. Hemolymph was collected either immediately after termination of exposure (F24 group) or 24 h later (F48 group). Apoptosis/necrosis tests were performed in hemocytes using fluorescence microscopy and flow cytometry, while ELISA tests were used to measure eicosanoid levels. Apoptosis and necrosis occurred to the same degree in F24, but necrosis predominated in F48. Fungal infection resulted in caspase activation, increased PGE1, PGE2, PGA1, PGF2α, and 8-iso-PGF2α levels and decreased TXB2 levels, but had no effect on TXA2 or 11-dehydro-TXB2 concentrations. In addition, infected larvae demonstrated significantly increased PLA2 activity, known to be involved in eicosanoid biosynthesis. Our findings indicate that fungal infection simultaneously induces apoptosis in insects and stimulates general caspase activity, and this may be correlated with changes in the concentrations of eicosanoids.
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Affiliation(s)
| | - Agata Kaczmarek
- Witold Stefański Institute of Parasitology, Polish Academy of Sciences, Warsaw, Poland
| | - Michalina Kazek
- Witold Stefański Institute of Parasitology, Polish Academy of Sciences, Warsaw, Poland
| | - Mieczysława Irena Boguś
- Witold Stefański Institute of Parasitology, Polish Academy of Sciences, Warsaw, Poland.,BIOMIBO, Warsaw, Poland
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Winter A, Schmid R, Bayliss R. Structural Insights into Separase Architecture and Substrate Recognition through Computational Modelling of Caspase-Like and Death Domains. PLoS Comput Biol 2015; 11:e1004548. [PMID: 26513470 PMCID: PMC4626109 DOI: 10.1371/journal.pcbi.1004548] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 08/31/2015] [Indexed: 11/18/2022] Open
Abstract
Separases are large proteins that mediate sister chromatid disjunction in all eukaryotes. They belong to clan CD of cysteine peptidases and contain a well-conserved C-terminal catalytic protease domain similar to caspases and gingipains. However, unlike other well-characterized groups of clan CD peptidases, there are no high-resolution structures of separases and the details of their regulation and substrate recognition are poorly understood. Here we undertook an in-depth bioinformatical analysis of separases from different species with respect to their similarity in amino acid sequence and protein fold in comparison to caspases, MALT-1 proteins (mucosa-associated lymphoidtissue lymphoma translocation protein 1) and gingipain-R. A comparative model of the single C-terminal caspase-like domain in separase from C. elegans suggests similar binding modes of substrate peptides between these protein subfamilies, and enables differences in substrate specificity of separase proteins to be rationalised. We also modelled a newly identified putative death domain, located N-terminal to the caspase-like domain. The surface features of this domain identify potential sites of protein-protein interactions. Notably, we identified a novel conserved region with the consensus sequence WWxxRxxLD predicted to be exposed on the surface of the death domain, which we termed the WR motif. We envisage that findings from our study will guide structural and functional studies of this important protein family. The separation of sister chromatids is a crucial step in cell division and is triggered by the activation of separase, a protease that cleaves the proteins that maintain the cohesion between sister chromatids. Knowledge of the molecular structure and activation mechanism of separase is limited by the difficulty of obtaining structural information on this large and flexible protein. Sequence conservation between separase homologues from diverse species is limited to the C-terminal region that contains the catalytically active protease domain. We conducted an in-depth bioinformatical analysis of separase and generated structural models of the two conserved domains that comprise the C-terminal region: a caspase-like domain and a putative death domain. This analysis provided insights into substrate recognition and identified potential sites of protein-protein interactions. Both the death domain and caspase-like domain are well-conserved in separases, which suggests an evolutionary pressure to keep these two domains together, perhaps to enable separase activity and/or provide stability. Insights into the molecular structures of separase gained in this study may provide a starting point for experimental structural studies on this protein and may aid therapeutic development against cancers where chromosomes are improperly segregated.
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Affiliation(s)
- Anja Winter
- Department of Biochemistry, University of Leicester, Leicester, United Kingdom
| | - Ralf Schmid
- Department of Biochemistry, University of Leicester, Leicester, United Kingdom
| | - Richard Bayliss
- Department of Biochemistry, University of Leicester, Leicester, United Kingdom
- * E-mail:
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Ying Z, Li A, Lu Z, Wu C, Yin H, Yuan M, Pang Y. The Spodoptera frugiperda effector caspase Sf-caspase-1 becomes unstable following its activation. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2013; 83:195-210. [PMID: 23740663 DOI: 10.1002/arch.21106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Sf-caspase-1 is the principal effector caspase in Spodoptera frugiperda cells. Like the caspases in other organisms, Sf-caspase-1 is processed by upstream caspases to form an active heterotetramer composed of the p19 and p12 subunits. The regulation of active caspases is crucial for cellular viability. In mammal cells, the subunits and the active form of caspase-3 were rapidly degraded relative to its proenzyme form. In the present study, the S. frugiperda Sf9 cells were transiently transfected with plasmids encoding different fragments of Sf-caspase-1: the pro-Sf-caspase-1 (p37), a prodomain deleted fragment (p31), a fragment containing the large subunit and the prodomain (p25), the large subunit (p19), and the small subunit (p12). Flow cytometry and Western blot analysis revealed that p12, p19, and p25 were unstable in the transfected cells, in contrast to p37 and p31. Lactacystin, a proteasome inhibitor, increased the accumulation of the p19 and p12 subunits, suggesting that the degradation is performed by the ubiquitin-proteasome system. During the activation, the Sf-caspase-1 produces an intermediate form and then undergoes proteolytic processing to form active Sf-caspase-1. We found that both the active and the intermediate form were unstable, indicating that once activated or during its activation, the Sf-caspase-1 was unstable.
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Affiliation(s)
- Zhongfu Ying
- State Key Laboratory of Biocontrol, Sun Yat-sen University, Guangzhou, PR China
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Lu MX, Du YZ, Cao SS, Liu P, Li J. Molecular cloning and characterization of the first caspase in the Striped Stem Borer, Chilo suppressalis. Int J Mol Sci 2013; 14:10229-41. [PMID: 23676354 PMCID: PMC3676837 DOI: 10.3390/ijms140510229] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 04/17/2013] [Accepted: 05/03/2013] [Indexed: 11/25/2022] Open
Abstract
Apoptosis is executed through the activity of the caspases that are aspartyl-specific proteases. In this study, we isolated the caspase gene (Cscaspase-1) of Chilo suppressalis (one of the leading pests responsible for destruction of rice crops). It possesses the open reading frame (ORF) of 295 amino acids including prodomain, large subunit and small subunits, and two cleavage sites (Asp23 and Asp194) were found to be located among them. In addition to these profiles, Cscaspase-1 contains two active sites (His134 and Cys176). Genomic analysis demonstrated there was no intron in the genome of Cscaspase-1. The Cscaspase-1 transcripts were found in all tissues of the fifth instar larvae, and higher levels were found in the midgut, hindgut and Malpighian tubules. Examination of Cscaspase-1 expression in different developmental stages indicated low constitutive levels in the eggs and early larvae stages, and higher abundances were exhibited in the last larvae and pupae stages. The relative mRNA levels of Cscaspase-1 were induced by heat and cold temperatures. For example, the highest increase of Cscaspase-1 transcription was at −3 °C and 36 °C respectively. In a word, Cscaspase-1 plays a role of effector in the apoptosis of C. suppressalis. It also correlates with development, metamorphosis and thermotolerance of C. suppreassalis.
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Affiliation(s)
- Ming-Xing Lu
- College of Horticulture and Plant Protection & Institute of Applied Entomology, Yangzhou University, Yangzhou 225009, Jiangsu, China; E-Mails: (M.-X.L.); (S.-S.C.)
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA; E-Mail:
| | - Yu-Zhou Du
- College of Horticulture and Plant Protection & Institute of Applied Entomology, Yangzhou University, Yangzhou 225009, Jiangsu, China; E-Mails: (M.-X.L.); (S.-S.C.)
- Authors to whom correspondence should be addressed; E-Mails: (Y.-Z.D.); (J.L.); Tel./Fax: +86-514-8797-1854 (Y.-Z.D.); Tel.: +1-540-231-1182 (J.L.); Fax: +1-540-231-9070 (J.L.)
| | - Shuang-Shuang Cao
- College of Horticulture and Plant Protection & Institute of Applied Entomology, Yangzhou University, Yangzhou 225009, Jiangsu, China; E-Mails: (M.-X.L.); (S.-S.C.)
| | - Pingyang Liu
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA; E-Mail:
| | - Jianyong Li
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA; E-Mail:
- Authors to whom correspondence should be addressed; E-Mails: (Y.-Z.D.); (J.L.); Tel./Fax: +86-514-8797-1854 (Y.-Z.D.); Tel.: +1-540-231-1182 (J.L.); Fax: +1-540-231-9070 (J.L.)
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de Diego I, Veillard FT, Guevara T, Potempa B, Sztukowska M, Potempa J, Gomis-Rüth FX. Porphyromonas gingivalis virulence factor gingipain RgpB shows a unique zymogenic mechanism for cysteine peptidases. J Biol Chem 2013; 288:14287-14296. [PMID: 23558682 DOI: 10.1074/jbc.m112.444927] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Zymogenicity is a regulatory mechanism that prevents inadequate catalytic activity in the wrong context. It plays a central role in maintaining microbial virulence factors in an inactive form inside the pathogen until secretion. Among these virulence factors is the cysteine peptidase gingipain B (RgpB), which is the major virulence factor secreted by the periodontopathogen Porphyromonas gingivalis that attacks host vasculature and defense proteins. The structure of the complex between soluble mature RgpB, consisting of a catalytic domain and an immunoglobulin superfamily domain, and its 205-residue N-terminal prodomain, the largest structurally characterized to date for a cysteine peptidase, reveals a novel fold for the prodomain that is distantly related to sugar-binding lectins. It attaches laterally to the catalytic domain through a large concave surface. The main determinant for latency is a surface "inhibitory loop," which approaches the active-site cleft of the enzyme on its non-primed side in a substrate-like manner. It inserts an arginine (Arg(126)) into the S1 pocket, thus matching the substrate specificity of the enzyme. Downstream of Arg(126), the polypeptide leaves the cleft, thereby preventing cleavage. Moreover, the carbonyl group of Arg(126) establishes a very strong hydrogen bond with the co-catalytic histidine, His(440), pulling it away from the catalytic cysteine, Cys(473), and toward Glu(381), which probably plays a role in orienting the side chain of His(440) during catalysis. The present results provide the structural determinants of zymogenic inhibition of RgpB by way of a novel inhibitory mechanism for peptidases in general and open the field for the design of novel inhibitory strategies in the treatment of human periodontal disease.
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Affiliation(s)
- Iñaki de Diego
- Proteolysis Laboratory, Molecular Biology Institute of Barcelona, Spanish Research Council (CSIC), Barcelona Science Park, c/Baldiri Reixac, 15-21, 08028 Barcelona, Catalonia, Spain
| | - Florian T Veillard
- University of Louisville School of Dentistry, Louisville, Kentucky 40202
| | - Tibisay Guevara
- Proteolysis Laboratory, Molecular Biology Institute of Barcelona, Spanish Research Council (CSIC), Barcelona Science Park, c/Baldiri Reixac, 15-21, 08028 Barcelona, Catalonia, Spain
| | - Barbara Potempa
- University of Louisville School of Dentistry, Louisville, Kentucky 40202
| | - Maryta Sztukowska
- University of Louisville School of Dentistry, Louisville, Kentucky 40202
| | - Jan Potempa
- University of Louisville School of Dentistry, Louisville, Kentucky 40202; Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland.
| | - F Xavier Gomis-Rüth
- Proteolysis Laboratory, Molecular Biology Institute of Barcelona, Spanish Research Council (CSIC), Barcelona Science Park, c/Baldiri Reixac, 15-21, 08028 Barcelona, Catalonia, Spain.
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Reactive-site cleavage residues confer target specificity to baculovirus P49, a dimeric member of the P35 family of caspase inhibitors. J Virol 2008; 82:7504-14. [PMID: 18508888 DOI: 10.1128/jvi.00231-08] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Baculovirus proteins P49 and P35 are potent suppressors of apoptosis in diverse organisms. Although related, P49 and P35 inhibit initiator and effector caspases, respectively, during infection of permissive insect cells. The molecular basis of this novel caspase specificity is unknown. To advance strategies for selective inhibition of the cell death caspases, we investigated biochemical differences between these baculovirus substrate inhibitors. We report here that P49 and P35 use similar mechanisms for stoichiometric inhibition that require caspase cleavage of their reactive site loops (RSL) and chemical contributions of a conserved N-terminal cysteine to stabilize the resulting inhibitory complex. Our data indicated that P49 functions as a homodimer that simultaneously binds two caspases. In contrast, P35 is a monomeric, monovalent inhibitor. P49 and P35 also differ in their RSL caspase recognition sequences. We tested the role of the P(4)-P(1) recognition motif for caspase specificity by monitoring virus-induced proteolytic processing of Sf-caspase-1, the principal effector caspase of the host insect Spodoptera frugiperda. When P49's TVTD recognition motif was replaced with P35's DQMD motif, P49 was impaired for inhibition of the initiator caspase that cleaves and activates pro-Sf-caspase-1 and instead formed a stable inhibitory complex with active Sf-caspase-1. In contrast, the effector caspase specificity of P35 was unaltered when P35's DQMD motif was replaced with TVTD. We concluded that the TVTD recognition motif is required but not sufficient for initiator caspase inhibition by P49. Our findings demonstrate a critical role for the P(4)-P(1) recognition site in caspase specificity by P49 and P35 and indicate that additional determinants are involved in target selection.
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7
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Lannan E, Vandergaast R, Friesen PD. Baculovirus caspase inhibitors P49 and P35 block virus-induced apoptosis downstream of effector caspase DrICE activation in Drosophila melanogaster cells. J Virol 2007; 81:9319-30. [PMID: 17582002 PMCID: PMC1951404 DOI: 10.1128/jvi.00247-07] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Baculoviruses induce widespread apoptosis in invertebrates. To better understand the pathways by which these DNA viruses trigger apoptosis, we have used a combination of RNA silencing and overexpression of viral and host apoptotic regulators to identify cell death components in the model system of Drosophila melanogaster. Here we report that the principal effector caspase DrICE is required for baculovirus-induced apoptosis of Drosophila DL-1 cells as demonstrated by RNA silencing. proDrICE was proteolytically cleaved and activated during infection. Activation was blocked by overexpression of the cellular inhibitor-of-apoptosis proteins DIAP1 and SfIAP but not by the baculovirus caspase inhibitor P49 or P35. Rather, the substrate inhibitors P49 and P35 prevented virus-induced apoptosis by arresting active DrICE through formation of stable inhibitory complexes. Consistent with a two-step activation mechanism, proDrICE was cleaved at the large/small subunit junction TETD(230)-G by a DIAP1-inhibitable, P49/P35-resistant protease and then at the prodomain junction DHTD(28)-A by a P49/P35-sensitive protease. Confirming that P49 targeted DrICE and not the initiator caspase DRONC, depletion of DrICE by RNA silencing suppressed virus-induced cleavage of P49. Collectively, our findings indicate that whereas DIAP1 functions upstream to block DrICE activation, P49 and P35 act downstream by inhibiting active DrICE. Given that P49 has the potential to inhibit both upstream initiator caspases and downstream effector caspases, we conclude that P49 is a broad-spectrum caspase inhibitor that likely provides a selective advantage to baculoviruses in different cellular backgrounds.
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Affiliation(s)
- Erica Lannan
- Institute for Molecular Virology, University of Wisconsin-Madison, Madison, WI 53706-1596, USA
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Meitzler JL, Gray JJ, Hendrickson TL. Truncation of the caspase-related subunit (Gpi8p) of Saccharomyces cerevisiae GPI transamidase: Dimerization revealed. Arch Biochem Biophys 2007; 462:83-93. [PMID: 17475206 DOI: 10.1016/j.abb.2007.03.035] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2007] [Revised: 03/15/2007] [Accepted: 03/16/2007] [Indexed: 11/24/2022]
Abstract
Eukaryotic proteins can be post-translationally modified with a glycosylphosphatidylinositol (GPI) membrane anchor. This modification reaction is catalyzed by GPI transamidase (GPI-T), a multimeric, membrane-bound enzyme. Gpi8p, an essential component of GPI-T, shares low sequence similarity with caspases and contains all or part of the enzyme's active site [U. Meyer, M. Benghezal, I. Imhof, A. Conzelmann, Biochemistry 39 (2000) 3461-3471]. Structural predictions suggest that the soluble portion of Gpi8p is divided into two domains: a caspase-like domain that contains the active site machinery and a second, smaller domain of unknown function. Based on these predictions, we evaluated a soluble truncation of Gpi8p (Gpi8(23-306)). Dimerization was investigated due to the known proclivity of caspases to homodimerize; a Gpi8(23-306) homodimer was detected by native gel and confirmed by mass spectrometry and N-terminal sequencing. Mutations at the putative caspase-like dimerization interface disrupted dimer formation. When combined, these results demonstrate an organizational similarity between Gpi8p and caspases.
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Affiliation(s)
- Jennifer L Meitzler
- Department of Chemistry, Remsen Hall, Johns Hopkins University, Baltimore, MD 21218, USA
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Bravarenko NI, Onufriev MV, Stepanichev MY, Ierusalimsky VN, Balaban PM, Gulyaeva NV. Caspase-like activity is essential for long-term synaptic plasticity in the terrestrial snail Helix. Eur J Neurosci 2006; 23:129-40. [PMID: 16420423 DOI: 10.1111/j.1460-9568.2005.04549.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Although caspase activity in the nervous system of mollusks has not been described before, we suggested that these cysteine proteases might be involved in the phenomena of neuroplasticity in mollusks. We directly measured caspase-3 (DEVDase) activity in the Helix lucorum central nervous system (CNS) using a fluorometrical approach and showed that the caspase-3-like immunoreactivity is present in the central neurons of Helix. Western blots revealed the presence of caspase-3-immunoreactive proteins with a molecular mass of 29 kDa. Staurosporin application, routinely used to induce apoptosis in mammalian neurons through the activating cleavage of caspase-3, did not result in the appearance of a smaller subunit corresponding to the active caspase in the snail. However, it did increase the enzyme activity in the snail CNS. This suggests differences in the regulation of caspase-3 activity in mammals and snails. In the snail CNS, the caspase homolog seems to possess an active center without activating cleavage typical for mammals. In electrophysiological experiments with identified snail neurons, selective blockade of the caspase-3 with the irreversible and cell-permeable inhibitor of caspase-3 N-benzyloxycarbonyl-Asp(OMe)-Glu(OMe)-Val-Asp-(OMe)-fluoro-methylketone prevented development of the long-term stage of synaptic input sensitization, suggesting that caspase is necessary for normal synaptic plasticity in snails. The results of our study give the first direct evidence that the caspase-3-like activity is essential for long-term plasticity in the invertebrate neurons. This activity is presumably involved in removing inhibitory constraints on the storage of long-term memory.
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Affiliation(s)
- N I Bravarenko
- Institute of Higher Nervous Activity and Neurophysiology, Butlerova 5A, Moscow 117485, Russia
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Liu Q, Chejanovsky N. Activation pathways and signal-mediated upregulation of the insect Spodoptera frugiperda caspase-1. Apoptosis 2006; 11:487-96. [PMID: 16532278 DOI: 10.1007/s10495-006-5059-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Sf-caspase-1 is the most studied effector caspase of Lepidoptera. Its activation is believed to follow a two-step mechanism: The first step requires cleavage by an initiator caspase at D195 (between the large and small subunits) releasing the C-terminal small subunit. This is blocked by the baculovirus caspase inhibitor P49. The second step removes the N-terminal prodomain by cleavage at D28 to generate the large subunit that is blocked by the baculovirus caspase inhibitor P35. In this study, we identified an alternative mechanism of Sf-caspase-1 activation. This additional two-step mechanism involves first cleavage of pro-Sf-caspase-1 at D28 to remove the N-terminal prodomain and subsequently cleavage at D195 to generate the large and small subunits. Both mechanisms are triggered by apoptotic stimuli following a distinct pattern. We also showed that expression of Sf-caspase-1 was upregulated upon reception of apoptotic stimuli. Different from all published data, this upregulation occurred as a post-transcriptional event. Moreover, we proved that the stronger the stimuli, the higher the upregulation. And we demonstrated that P49 and P35 inhibited the cleavage at D28 and D195 respectively, independently of wether the first cleavage was at D195 or at D28.
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Affiliation(s)
- Q Liu
- Entomology Department, Institute of Plant Protection, Agricultural Research Organization, The Volcani Center, POB 6, Bet Dagan, 50250, Israel.
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Liu Q, Qi Y, Chejanovsky N. Spodoptera littoralis caspase-1, a Lepidopteran effector caspase inducible by apoptotic signaling. Apoptosis 2005; 10:787-95. [PMID: 16133869 DOI: 10.1007/s10495-005-0365-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV) can successfully infect Spodoptera frugiperda SF9 cells, but in contrast, in Spodoptera littoralis SL2 cells it induces apoptosis aborting the infection. To understand better the mechanism of induction and execution of apoptosis in SL2 cells, we identified and characterized the first Spodoptera littoralis caspase, Sl-caspase-1. Sl-caspase-1 is an effector caspase that cleaves DEVD but not IETD and LEHD substrates, and the caspase-3 inhibitor DQMD-CHO inhibited this activity. It was involved in two apoptotic pathways induced by UV irradiation and virus infection. Moreover processing of Sl-caspase-1 was a determinant factor for baculovirus induction of apoptosis in SL2 cells. Since very little is known on the regulation of expression of Lepidopteran caspases, we studied Sl-caspase-1 expression after exposure to apoptosis stimuli. We found that triggering apoptosis in SL2 cells increased the steady-state level of Sl-caspase-1 without changing the level of sl-caspase-1 mRNA, suggesting that Sl-caspase-1 was post-transcriptionally up regulated. This regulation might occur as an early event in transduction of the apoptotic signal.
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Affiliation(s)
- Q Liu
- Entomology Department, Institute of Plant Protection, Agricultural Research Organization, The Volcani Center, POB 6, Bet Dagan, 50250 Israel
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Abstract
Caspases, which are the executioners of apoptosis, comprise two distinct classes, the initiators and the effectors. Although general structural features are shared between the initiator and the effector caspases, their activation, inhibition and release of inhibition are differentially regulated. Biochemical and structural studies have led to important advances in understanding the underlying molecular mechanisms of caspase regulation. This article reviews these latest advances and describes our present understanding of caspase regulation during apoptosis.
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Affiliation(s)
- Stefan J Riedl
- Department of Molecular Biology, Princeton University, Lewis Thomas Laboratory, Washington Road, Princeton, New Jersey 08544, USA
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Fuentes-Prior P, Salvesen G. The protein structures that shape caspase activity, specificity, activation and inhibition. Biochem J 2004; 384:201-32. [PMID: 15450003 PMCID: PMC1134104 DOI: 10.1042/bj20041142] [Citation(s) in RCA: 609] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2004] [Revised: 08/31/2004] [Accepted: 09/27/2004] [Indexed: 02/07/2023]
Abstract
The death morphology commonly known as apoptosis results from a post-translational pathway driven largely by specific limited proteolysis. In the last decade the structural basis for apoptosis regulation has moved from nothing to 'quite good', and we now know the fundamental structures of examples from the initiator phase, the pre-mitochondrial regulator phase, the executioner phase, inhibitors and their antagonists, and even the structures of some substrates. The field is as well advanced as the best known of proteolytic pathways, the coagulation cascade. Fundamentally new mechanisms in protease regulation have been disclosed. Structural evidence suggests that caspases have an unusual catalytic mechanism, and that they are activated by apparently unrelated events, depending on which position in the apoptotic pathway they occupy. Some naturally occurring caspase inhibitors have adopted classic inhibition strategies, but other have revealed completely novel mechanisms. All of the structural and mechanistic information can, and is, being applied to drive therapeutic strategies to combat overactivation of apoptosis in degenerative disease, and underactivation in neoplasia. We present a comprehensive review of the caspases, their regulators and inhibitors from a structural and mechanistic point of view, and with an aim to consolidate the many threads that define the rapid growth of this field.
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Key Words
- apoptosis
- caspase
- inhibitor
- inhibitor of apoptosis protein (iap)
- protease
- zymogen
- alps, autoimmune lymphoproliferative syndrome
- apaf-1, apoptotic protease activating factor-1
- asc/pycard, apoptosis-associated speck-like protein containing a card/pyd- and card-containing molecule
- bir, baculoviral iap repeat
- cad, caspase-activated dnase
- card, caspase-recruitment domain
- carp, caspase-associated ring protein
- ced, cell death-defective
- clarp, caspase-like apoptosis-regulatory protein
- cradd/raidd, caspase-2 and ripk1 domain-containing adaptor with death domain/rip-associated protein with a death domain
- crma, cytokine response modifier a
- dd, death domain
- ded, death effector domain
- dff, dna fragmentation factor
- diablo, direct iap-binding protein with low pi
- diap1, drosophila inhibitor of apoptosis 1
- disc, death-inducing signalling complex
- dronc, drosophila nedd2-like caspase
- fadd, fas (tnfrsf6)-associated via death domain
- flice, fadd-like ice
- flip, flice inhibitory protein
- iap, inhibitor of apoptosis protein
- ibm, iap binding motif
- icad, inhibitor of cad
- ice, interleukin-1β-converting enzyme
- ipaf/clan, ice-protease-activating factor/card, lrr and nacht-containing protein
- lrr, leucine-rich repeat
- nacht, ntpase-domain named after naip, ciita, het-e and tp1
- nalp1, nacht, lrr and pyrin domain containing 1
- nbd, nucleotide-binding domain
- nf-κb, nuclear factor-κb
- nod, nucleotide-binding and oligomerization domain-containing protein
- parp, poly(adp-ribose) polymerase
- pidd, p53-induced protein with a death domain
- rick/cardiak, rip-like interacting clarp kinase/card-containing ice-associated kinase
- ring, really interesting new gene
- rip, receptor-interacting protein
- serpin, serine protease inhibitor
- smac, second mitochondrial activator of caspases
- tfpi, tissue factor pathway inhibitor
- tlr, toll-like receptor
- tnf, tumour necrosis factor
- tradd, tnfrsf1a-associated via death domain
- traf, tnf receptor-associated factor
- trail, tnf-related apoptosis-inducing ligand
- xiap/birc4, x-linked iap/baculoviral iap repeat-containing 4
- p1, p2, …pn and p1′, p2′, …pm′ designate the side chains in substrates and inhibitors in the n- and c-terminal direction respectively from the p1–p1′ scissile peptide bond
- s1, s2, …sn and s1′, s2′, …sm′ refer to the cognate pockets on the protease that accept these side chains [1]
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Affiliation(s)
- Pablo Fuentes-Prior
- *Abteilung Strukturforschung, Max-Planck-Institut für Biochemie, Am Klopferspitz 18a, D82152, Planegg-Martinsried, Germany and Cardiovascular Research Center, Sant Antoni Ma. Claret 167, 08025 Barcelona, Spain
| | - Guy S. Salvesen
- †The Program in Apoptosis and Cell Death Research, Burnham Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, U.S.A
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