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Elisabeth Herniou - One of the best experts on this subject based on the ideXlab platform.
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New Insights into the Evolution of Entomopoxvirinae from the Complete Genome Sequences of Four Entomopoxviruses Infecting Adoxophyes honmai, Choristoneura biennis, Choristoneura rosaceana, and Mythimna separata
Journal of Virology, 2013Co-Authors: Julien Thézé, Julie Gallais, Basil Arif, Madoka Nakai, Daniel Doucet, Jun Takatsuka, Zhen Li, Elisabeth HerniouAbstract:Poxviruses are nucleocytoplasmic large DNA viruses encompassing two subfamilies, the Chordopoxvirinae and the Entomopoxvirinae, infecting vertebrates and insects, respectively. While chordopoxvirus genomics have been widely studied, only two entomopoxvirus (EPV) genomes have been entirely sequenced. We report the genome sequences of four EPVs of the Betaentomopoxvirus genus infecting the Lepidoptera: Adoxophyes honmai EPV (AHEV), Choristoneura biennis EPV (CBEV), Choristoneura rosaceana EPV (CREV), and Mythimna separata EPV (MySEV). The genomes are 80% AT rich, are 228 to 307 kbp long, and contain 247 to 334 open reading frames (ORFs). Most genes are homologous to those of Amsacta moorei entomopoxvirus and encode several protein families repeated in tandem in terminal regions. Some genomes also encode proteins of unknown functions with similarity to those of other insect viruses. Comparative genomic analyses highlight a high colinearity among the lepidopteran EPV genomes and little gene order conservation with other poxvirus genomes. As with previously sequenced EPVs, the genomes include a relatively conserved central region flanked by inverted terminal repeats. Protein clustering identified 104 core EPV genes. Among betaentomopoxviruses, 148 core genes were found in relatively high synteny, pointing to low genomic diversity. Whole-genome and spheroidin gene phylogenetic analyses showed that the lepidopteran EPVs group closely in a monophyletic lineage, corroborating their affiliation with the Betaentomopoxvirus genus as well as a clear division of the EPVs according to the orders of insect hosts (Lepidoptera, Coleoptera, and Orthoptera). This suggests an ancient coevolution of EPVs with their insect hosts and the need to revise the current EPV taxonomy to separate orthopteran EPVs from the lepidopteran-specific betaentomopoxviruses so as to form a new genus.
Julien Thézé - One of the best experts on this subject based on the ideXlab platform.
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New Insights into the Evolution of Entomopoxvirinae from the Complete Genome Sequences of Four Entomopoxviruses Infecting Adoxophyes honmai, Choristoneura biennis, Choristoneura rosaceana, and Mythimna separata
Journal of Virology, 2013Co-Authors: Julien Thézé, Julie Gallais, Basil Arif, Madoka Nakai, Daniel Doucet, Jun Takatsuka, Zhen Li, Elisabeth HerniouAbstract:Poxviruses are nucleocytoplasmic large DNA viruses encompassing two subfamilies, the Chordopoxvirinae and the Entomopoxvirinae, infecting vertebrates and insects, respectively. While chordopoxvirus genomics have been widely studied, only two entomopoxvirus (EPV) genomes have been entirely sequenced. We report the genome sequences of four EPVs of the Betaentomopoxvirus genus infecting the Lepidoptera: Adoxophyes honmai EPV (AHEV), Choristoneura biennis EPV (CBEV), Choristoneura rosaceana EPV (CREV), and Mythimna separata EPV (MySEV). The genomes are 80% AT rich, are 228 to 307 kbp long, and contain 247 to 334 open reading frames (ORFs). Most genes are homologous to those of Amsacta moorei entomopoxvirus and encode several protein families repeated in tandem in terminal regions. Some genomes also encode proteins of unknown functions with similarity to those of other insect viruses. Comparative genomic analyses highlight a high colinearity among the lepidopteran EPV genomes and little gene order conservation with other poxvirus genomes. As with previously sequenced EPVs, the genomes include a relatively conserved central region flanked by inverted terminal repeats. Protein clustering identified 104 core EPV genes. Among betaentomopoxviruses, 148 core genes were found in relatively high synteny, pointing to low genomic diversity. Whole-genome and spheroidin gene phylogenetic analyses showed that the lepidopteran EPVs group closely in a monophyletic lineage, corroborating their affiliation with the Betaentomopoxvirus genus as well as a clear division of the EPVs according to the orders of insect hosts (Lepidoptera, Coleoptera, and Orthoptera). This suggests an ancient coevolution of EPVs with their insect hosts and the need to revise the current EPV taxonomy to separate orthopteran EPVs from the lepidopteran-specific betaentomopoxviruses so as to form a new genus.
Richard W. Moyer - One of the best experts on this subject based on the ideXlab platform.
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amsacta moorei entomopoxvirus inhibitor of apoptosis suppresses cell death by binding grim and hid
Journal of Virology, 2005Co-Authors: Qianjun Li, Natasha Schokman, Jenny Mei Ho, Peter Liston, Richard W. MoyerAbstract:Inhibitor of apoptosis (iap) genes have been identified in the genomes of two independent families of insect viruses, the Baculoviridae and the Entomopoxvirinae. In this report, we examined the functional attributes of the Amsacta moorei entomopoxvirus-encoded IAP protein (AMV-IAP). The binding specificity of the individual baculoviral IAP repeat (BIR) domains of AMV-IAP was investigated by using a random-peptide, phage display library, and sequences similar to the amino termini of proapoptotic Drosophila proteins in the Reaper/Hid/Grim family were identified. Furthermore, the BIR domains of AMV-IAP protein were demonstrated to bind the mammalian IAP inhibitor Smac through the AVPI tetrapeptide sequence, suggesting that the peptide binding pocket and groove found in the insect and mammalian IAPs is conserved in this viral protein. Interaction analysis implicated BIR1 as the high-affinity site for Grim, while BIR2 interacted more strongly with Hid. Both Grim and Hid were demonstrated to interact with AMV-IAP in vivo, and Grim- or Hid-induced cell death was suppressed when AMV-IAP was coexpressed.
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Functional Analysis of the Inhibitor of Apoptosis (iap) Gene Carried by the Entomopoxvirus of Amsacta moorei
Journal of Virology, 2005Co-Authors: Qianjun Li, Peter Liston, Richard W. MoyerAbstract:Apoptosis, or programmed cell death, is a well-conserved and integral process necessary for normal organism development which serves to remove unwanted, damaged, mutated, or infected cells (43, 54, 70). Apoptosis can be initiated by both external and internal stimuli such as UV-induced DNA damage, oncogenic transformation, drugs such as actinomycin D, virus infection, and a variety of extracellular signals (68, 71). These various stimuli lead to the activation of either the intrinsic or extrinsic apoptotic pathway (7). The extrinsic pathway is triggered by the binding of external (death) ligands to their cognate (death) receptors as exemplified by members of the tumor necrosis factor (TNF) superfamily. Receptor-ligand engagement then allows transmission of external signals into the cell. The intrinsic pathway is initiated by signals originating within the cell from a series of death-triggering genes, which in insect systems include the hid, grim, and reaper genes of Drosophila and in mammalian cells the Smac/Diablo, GSPT1, and Omi/HtrA2 genes (39, 68). The apoptotic killing of cells by these death-inducing genes can be blocked and regulated by apoptotic suppressor genes, including members of the inhibitor of apoptosis (iap) gene superfamily (26, 59). Both intrinsic and extrinsic apoptotic pathways result in the formation of a cytosolic protein complex that activates a family of aspartic acid-specific cysteine proteases (caspases). Caspases are a diverse family of proteases, and it is through the action of active caspases that apoptotic death occurs. Caspases are divided into “initiator” (caspases 2, 8, 9, and 10) and “executioner” or “terminal” caspases (caspases 3 and 7) (35, 54). Once activated, the initiator caspases are responsible for activating the executioner caspases by proteolytic cleavage. The activated executioner caspases are then responsible for the proteolytic cleavage and degradation of a broad spectrum of cellular targets, eventually leading to apoptosis that is characterized by changes in the cells such as shrinkage, membrane blebbing, chromatin condensation, formation of the apoptosome, and DNA fragmentation (54, 71). Virus infections frequently lead to the induction of apoptosis in host cells. Apoptosis in infected cells can be considered as a host defense mechanism which ultimately results in reduction of virus production (7, 43). However, viruses have developed strategies to block apoptosis allowing more time for progeny virus to be produced (7, 11, 27, 48). One of the first apoptotic suppressor genes, p35, was discovered in Autographa californica M nucleopolyhedrovirus (AcMNPV). The p35 gene is required for virus growth since deletion of p35 from AcMNPV blocks virus production (13). The P35 protein is believed to function in the terminal stages of apoptosis as a caspase inhibitor that acts to block the lethal effects of terminal caspase activation and prevent cell death. In addition to P35, baculoviruses also encode at least two other types of apoptotic suppressor proteins, P49 and IAP (12, 17, 41, 73). The P49 protein, produced by the Spodoptera littoralis nucleopolyhedrosis virus, inhibits the activation of initiator caspases, including human caspase-9 and the other P35-sensitive initiator caspases (17, 46, 73). Thus, P49 functions to inhibit apoptosis by blocking activity of the initiator caspases that serves to prevent activation of the downstream effector caspases. Viral iap genes were first described from the Orgyia pseudotsugata M nucleopolyhedrovirus (OpMNPV), the Op-iap gene, and Cydia pomonella granulosis virus (CpGV), the Cp-iap (8, 15). Structurally, IAPs are characterized by the presence of two signature motifs: the so-called baculovirus IAP repeats (BIRs) and a RING domain (16, 59). RING domains are a specialized form of zinc finger involved in protein-protein interactions. IAP proteins generally act to block apoptosis by interacting through the BIR domain to block the activity of a variety of proapoptotic proteins such as REAPER, HID, and GRIM in insect cells and SMAC/DIABLO in vertebrate cells (34, 63). Op-IAP has been shown to bind to HID, REAPER, and GRIM; to down-regulate Sf-caspase-X; and therefore to inhibit apoptosis induced by various proapoptotic inducers (34, 63). The IAP family of proteins is evolutionarily well conserved, and most IAP proteins appear to be able to function across different species. Unlike p35 and p49 genes, which have only been identified in a few baculoviruses, iap genes have been found widely distributed in most if not all baculoviruses, as well as in eukaryotes, including mammals (16). The Poxviridae comprise a large family of double-stranded DNA-containing viruses, which, unlike baculoviruses, develop in the cytoplasm and include viruses of both vertebrates (Chordopoxvirinae) and invertebrates (Entomopoxvirinae). The vertebrate poxviruses are known to encode a number of proteins that regulate apoptosis, including the serine proteinase inhibitor (serpin), SPI-2/CrmA. The crmA/SPI-2-encoded serpin blocks apoptosis by direct inhibition of initiator caspases, including caspases 1, 8, and 10 (69), as well as granzyme B (40, 47, 58). However, no serpin genes have been identified within the two sequenced insect poxvirus genomes, the entomopoxviruses from Amsacta moorei (AmEPV) (5) and Melanoplus sanguinipes (MsEPV) (1). Furthermore, examination of the genomic sequences suggests none of the many other vertebrate poxvirus apoptosis suppressors exist within AmEPV. AmEPV, a group B (β) entomopoxvirus, has been reported to infect agriculturally important pests, such as Estigmene acrea (24) and Lymantria dispar (5). The 232-kb AmEPV genome was recently sequenced (5) and appears to contain a single iap gene, AMViap (AMV021). As the only candidate apoptotic suppressor gene, it is likely that the single AmEPV iap gene homolog has a role in controlling apoptosis. In this paper, we show that the AMViap gene is active, inhibits apoptosis as expected, and represents one mechanism by which AmEPV can control cell viability.
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The Non-Permissive Infection of Insect (Gypsy Moth) LD-652 Cells by Vaccinia Virus
Virology, 1998Co-Authors: Yi Li, Shala Yuan, Richard W. MoyerAbstract:Abstract The members of Poxviridae family are among the most complex of animal viruses and subfamily members infect both vertebrate ( Chordopoxvirinae ) and invertebrate ( Entomopoxvirinae ) hosts, respectively. Vaccinia virus (VV) is the most commonly studied vertebrate virus and the entomopoxvirus of Amsacta moorei (AmEPV) is the prototypic insect virus. AmEPV, while not able to productively infect vertebrate cells, does enter vertebrate cells and expresses early genes after which the infection aborts although the cells survive (Y. Li, R. L. Hall, and R. W. Moyer. J.Virol. 71(12), 95579562, 1997). We show here that a recombinant VV, containing the lacZ gene regulated by the cowpox virus A-type inclusion (ATI) late promoter, likewise does not productively infect insect cells. Our results suggest that the recombinant VV enters insect cells, host protein synthesis is inhibited, early gene expression is normal, and viral DNA replication occurs as does late protein synthesis. However, little if any proteolytic processing of late viral proteins, typical of morphogenesis, is observed. Electron micrographs of infected cells suggest that while cytoplasmic virosomes (factories) are formed, there is little indication of further morphogenesis or any formation of mature virions. Therefore, while both orthopoxviruses and entomopoxviruses fail to replicate in heterologous hosts, the nature of abortive infections is quite different.
Julie Gallais - One of the best experts on this subject based on the ideXlab platform.
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New Insights into the Evolution of Entomopoxvirinae from the Complete Genome Sequences of Four Entomopoxviruses Infecting Adoxophyes honmai, Choristoneura biennis, Choristoneura rosaceana, and Mythimna separata
Journal of Virology, 2013Co-Authors: Julien Thézé, Julie Gallais, Basil Arif, Madoka Nakai, Daniel Doucet, Jun Takatsuka, Zhen Li, Elisabeth HerniouAbstract:Poxviruses are nucleocytoplasmic large DNA viruses encompassing two subfamilies, the Chordopoxvirinae and the Entomopoxvirinae, infecting vertebrates and insects, respectively. While chordopoxvirus genomics have been widely studied, only two entomopoxvirus (EPV) genomes have been entirely sequenced. We report the genome sequences of four EPVs of the Betaentomopoxvirus genus infecting the Lepidoptera: Adoxophyes honmai EPV (AHEV), Choristoneura biennis EPV (CBEV), Choristoneura rosaceana EPV (CREV), and Mythimna separata EPV (MySEV). The genomes are 80% AT rich, are 228 to 307 kbp long, and contain 247 to 334 open reading frames (ORFs). Most genes are homologous to those of Amsacta moorei entomopoxvirus and encode several protein families repeated in tandem in terminal regions. Some genomes also encode proteins of unknown functions with similarity to those of other insect viruses. Comparative genomic analyses highlight a high colinearity among the lepidopteran EPV genomes and little gene order conservation with other poxvirus genomes. As with previously sequenced EPVs, the genomes include a relatively conserved central region flanked by inverted terminal repeats. Protein clustering identified 104 core EPV genes. Among betaentomopoxviruses, 148 core genes were found in relatively high synteny, pointing to low genomic diversity. Whole-genome and spheroidin gene phylogenetic analyses showed that the lepidopteran EPVs group closely in a monophyletic lineage, corroborating their affiliation with the Betaentomopoxvirus genus as well as a clear division of the EPVs according to the orders of insect hosts (Lepidoptera, Coleoptera, and Orthoptera). This suggests an ancient coevolution of EPVs with their insect hosts and the need to revise the current EPV taxonomy to separate orthopteran EPVs from the lepidopteran-specific betaentomopoxviruses so as to form a new genus.
Basil Arif - One of the best experts on this subject based on the ideXlab platform.
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New Insights into the Evolution of Entomopoxvirinae from the Complete Genome Sequences of Four Entomopoxviruses Infecting Adoxophyes honmai, Choristoneura biennis, Choristoneura rosaceana, and Mythimna separata
Journal of Virology, 2013Co-Authors: Julien Thézé, Julie Gallais, Basil Arif, Madoka Nakai, Daniel Doucet, Jun Takatsuka, Zhen Li, Elisabeth HerniouAbstract:Poxviruses are nucleocytoplasmic large DNA viruses encompassing two subfamilies, the Chordopoxvirinae and the Entomopoxvirinae, infecting vertebrates and insects, respectively. While chordopoxvirus genomics have been widely studied, only two entomopoxvirus (EPV) genomes have been entirely sequenced. We report the genome sequences of four EPVs of the Betaentomopoxvirus genus infecting the Lepidoptera: Adoxophyes honmai EPV (AHEV), Choristoneura biennis EPV (CBEV), Choristoneura rosaceana EPV (CREV), and Mythimna separata EPV (MySEV). The genomes are 80% AT rich, are 228 to 307 kbp long, and contain 247 to 334 open reading frames (ORFs). Most genes are homologous to those of Amsacta moorei entomopoxvirus and encode several protein families repeated in tandem in terminal regions. Some genomes also encode proteins of unknown functions with similarity to those of other insect viruses. Comparative genomic analyses highlight a high colinearity among the lepidopteran EPV genomes and little gene order conservation with other poxvirus genomes. As with previously sequenced EPVs, the genomes include a relatively conserved central region flanked by inverted terminal repeats. Protein clustering identified 104 core EPV genes. Among betaentomopoxviruses, 148 core genes were found in relatively high synteny, pointing to low genomic diversity. Whole-genome and spheroidin gene phylogenetic analyses showed that the lepidopteran EPVs group closely in a monophyletic lineage, corroborating their affiliation with the Betaentomopoxvirus genus as well as a clear division of the EPVs according to the orders of insect hosts (Lepidoptera, Coleoptera, and Orthoptera). This suggests an ancient coevolution of EPVs with their insect hosts and the need to revise the current EPV taxonomy to separate orthopteran EPVs from the lepidopteran-specific betaentomopoxviruses so as to form a new genus.