The Experts below are selected from a list of 204 Experts worldwide ranked by ideXlab platform
Michele Barry - One of the best experts on this subject based on the ideXlab platform.
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Ectromelia virus encodes a family of ankyrin f box proteins that regulate nfκb
Virology, 2014Co-Authors: Kristin Burles, Nicholas Van Buuren, Michele BarryAbstract:A notable feature of poxviruses is their ability to inhibit the antiviral response, including the nuclear factor kappa B (NFκB) pathway. NFκB is a transcription factor that is sequestered in the cytoplasm until cell stimulation, and relies on the SCF (Skp1, culllin-1, F-box) ubiquitin ligase to target its inhibitor, IκBα, for degradation. IκBα is recruited to the SCF by the F-box domain-containing protein βTrCP. Here, we show that Ectromelia virus, the causative agent of mousepox, encodes four F-box-containing proteins, EVM002, EVM005, EVM154, and EVM165, all of which contain Ankyrin (Ank) domains. The Ank/F-box proteins inhibit NFκB nuclear translocation, and this inhibition is dependent on the F-box domain. We also demonstrate that EVM002, EVM005, EVM154, and EVM165 prevent IκBα degradation, suggesting that they target the SCF. This study identifies a new mechanism by which Ectromelia virus inhibits NFκB.
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Ectromelia virus encodes a family of Ankyrin/F-box proteins that regulate NFκB
Virology, 2014Co-Authors: Kristin Burles, Nicholas Van Buuren, Michele BarryAbstract:A notable feature of poxviruses is their ability to inhibit the antiviral response, including the nuclear factor kappa B (NFκB) pathway. NFκB is a transcription factor that is sequestered in the cytoplasm until cell stimulation, and relies on the SCF (Skp1, culllin-1, F-box) ubiquitin ligase to target its inhibitor, IκBα, for degradation. IκBα is recruited to the SCF by the F-box domain-containing protein βTrCP. Here, we show that Ectromelia virus, the causative agent of mousepox, encodes four F-box-containing proteins, EVM002, EVM005, EVM154, and EVM165, all of which contain Ankyrin (Ank) domains. The Ank/F-box proteins inhibit NFκB nuclear translocation, and this inhibition is dependent on the F-box domain. We also demonstrate that EVM002, EVM005, EVM154, and EVM165 prevent IκBα degradation, suggesting that they target the SCF. This study identifies a new mechanism by which Ectromelia virus inhibits NFκB.
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EVM005: an Ectromelia-encoded protein with dual roles in NF-κB inhibition and virulence.
PLoS pathogens, 2014Co-Authors: Nicholas Van Buuren, R. Mark L. Buller, Scott Parker, Jill Schriewer, Kristin Burles, Ninad Mehta, Michele BarryAbstract:Poxviruses contain large dsDNA genomes encoding numerous open reading frames that manipulate cellular signalling pathways and interfere with the host immune response. The NF-κB signalling cascade is an important mediator of innate immunity and inflammation, and is tightly regulated by ubiquitination at several key points. A critical step in NF-κB activation is the ubiquitination and degradation of the inhibitor of kappaB (IκBα), by the cellular SCFβ-TRCP ubiquitin ligase complex. We show here that upon stimulation with TNFα or IL-1β, Orthopoxvirus-infected cells displayed an accumulation of phosphorylated IκBα, indicating that NF-κB activation was inhibited during poxvirus infection. Ectromelia virus is the causative agent of lethal mousepox, a natural disease that is fatal in mice. Previously, we identified a family of four Ectromelia virus genes (EVM002, EVM005, EVM154 and EVM165) that contain N-terminal ankyrin repeats and C-terminal F-box domains that interact with the cellular SCF ubiquitin ligase complex. Since degradation of IκBα is catalyzed by the SCFβ-TRCP ubiquitin ligase, we investigated the role of the Ectromelia virus ankyrin/F-box protein, EVM005, in the regulation of NF-κB. Expression of Flag-EVM005 inhibited both TNFα- and IL-1β-stimulated IκBα degradation and p65 nuclear translocation. Inhibition of the NF-κB pathway by EVM005 was dependent on the F-box domain, and interaction with the SCF complex. Additionally, Ectromelia virus devoid of EVM005 was shown to inhibit NF-κB activation, despite lacking the EVM005 open reading frame. Finally, Ectromelia virus devoid of EVM005 was attenuated in both A/NCR and C57BL/6 mouse models, indicating that EVM005 is required for virulence and immune regulation in vivo.
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Ectromelia Virus Encodes a Novel Family of F-Box Proteins That Interact with the SCF Complex
Journal of virology, 2008Co-Authors: Nicholas Van Buuren, Brianne Couturier, Yue Xiong, Michele BarryAbstract:Poxviruses are notorious for encoding multiple proteins that regulate cellular signaling pathways, including the ubiquitin-proteasome system. Bioinformatics indicated that Ectromelia virus, the causative agent of lethal mousepox, encoded four proteins, EVM002, EVM005, EVM154, and EVM165, containing putative F-box domains. In contrast to cellular F-box proteins, the Ectromelia virus proteins contain C-terminal F-box domains in conjunction with N-terminal ankyrin repeats, a combination that has not been previously reported for cellular proteins. These observations suggested that the Ectromelia virus F-box proteins interact with SCF (Skp1, cullin-1, and F-box) ubiquitin ligases. We focused our studies on EVM005, since this protein had only one ortholog in cowpox virus. Using mass spectrometry, we identified cullin-1 as a binding partner for EVM005, and this interaction was confirmed by overexpression of hemagglutinin (HA)-cullin-1. During infection, Flag-EVM005 and HA-cullin-1 colocalized to distinct cellular bodies. Significantly, EVM005 coprecipitated with endogenous Skp1, cullin-1, and Roc1 and associated with conjugated ubiquitin, suggesting that EVM005 interacted with the components of a functional ubiquitin ligase. Interaction of EVM005 with cullin-1 and Skp1 was abolished upon deletion of the F-box, indicating that the F-box played a crucial role in interaction with the SCF complex. Additionally, EVM002 and EVM154 interacted with Skp1 and conjugated ubiquitin, suggesting that Ectromelia virus encodes multiple F-box-containing proteins that regulate the SCF complex. Our results indicate that Ectromelia virus has evolved multiple proteins that interact with the SCF complex.
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Ectromelia virus btb kelch proteins evm150 and evm167 interact with cullin 3 based ubiquitin ligases
Virology, 2008Co-Authors: Brianne A. Wilton, Nicholas Van Buuren, Yue Xiong, Stephanie Campbell, Robyn Garneau, Manabu Furukawa, Michele BarryAbstract:Cellular proteins containing BTB and kelch domains have been shown to function as adapters for the recruitment of substrates to cullin-3-based ubiquitin ligases. Poxviruses are the only family of viruses known to encode multiple BTB/kelch proteins, suggesting that poxviruses may modulate the ubiquitin pathway through interaction with cullin-3. Ectromelia virus encodes four BTB/kelch proteins and one BTB-only protein. Here we demonstrate that two of the Ectromelia virus-encoded BTB/kelch proteins, EVM150 and EVM167, interacted with cullin-3. Similar to cellular BTB proteins, the BTB domain of EVM150 and EVM167 was necessary and sufficient for cullin-3 interaction. During infection, EVM150 and EVM167 localized to discrete cytoplasmic regions, which co-localized with cullin-3. Furthermore, EVM150 and EVM167 co-localized and interacted with conjugated ubiquitin, as demonstrated by confocal microscopy and co-immunoprecipitation. Our findings suggest that the Ectromelia virus-encoded BTB/kelch proteins, EVM150 and EVM167, interact with cullin-3 potentially functioning to recruit unidentified substrates for ubiquitination.
Antonio Alcami - One of the best experts on this subject based on the ideXlab platform.
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A virus-encoded type I interferon decoy receptor enables evasion of host immunity through cell-surface binding
Nature Publishing Group, 2018Co-Authors: Bruno Hernáez, Juan Manuel Alonso-lobo, Imma Montanuy, Cornelius Fischer, Sascha Sauer, Luis Sigal, Noemí Sevilla, Antonio AlcamiAbstract:Secreted cytokine decoy receptors encoded by viruses can act as potent immune evasion proteins modulating antiviral immunity. Here Hernaez et al. show that cell surface binding is required for efficient evasion of the host response by a secreted virus encoded type I IFN decoy receptor of vaccinia and Ectromelia virus using an in vivo model of infection
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An Ectromelia virus protein that interacts with chemokines through their glycosaminoglycan binding domain.
Journal of Virology, 2008Co-Authors: M Begoña Ruiz-argüello, Vincent P. Smith, Gabriele S V Campanella, Françoise Baleux, Fernando Arenzana-seisdedos, Andrew D Luster, Antonio AlcamiAbstract:Poxviruses encode a number of secreted virulence factors that modulate the host immune response. The vaccinia virus A41 protein is an immunomodulatory protein with amino acid sequence similarity to the 35-kDa chemokine binding protein, but the host immune molecules targeted by A41 have not been identified. We report here that the vaccinia virus A41 ortholog encoded by Ectromelia virus, a poxvirus pathogen of mice, named E163 in the Ectromelia virus Naval strain, is a secreted 31-kDa glycoprotein that selectively binds a limited number of CC and CXC chemokines with high affinity. A detailed characterization of the interaction of Ectromelia virus E163 with mutant forms of the chemokines CXCL10 and CXCL12alpha indicated that E163 binds to the glycosaminoglycan binding site of the chemokines. This suggests that E163 inhibits the interaction of chemokines with glycosaminoglycans and provides a mechanism by which E163 prevents chemokine-induced leukocyte migration to the sites of infection. In addition to interacting with chemokines, E163 can interact with high affinity with glycosaminoglycan molecules, enabling E163 to attach to cell surfaces and to remain in the vicinity of the sites of viral infection. These findings identify E163 as a new chemokine binding protein in poxviruses and provide a molecular mechanism for the immunomodulatory activity previously reported for the vaccinia virus A41 ortholog. The results reported here also suggest that the cell surface and extracellular matrix are important targeting sites for secreted poxvirus immune modulators.
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Genetic Variability of Immunomodulatory Genes in Ectromelia Virus Isolates Detected by Denaturing High-Performance Liquid Chromatography
Journal of virology, 2003Co-Authors: Gloria Ribas, José Rivera, Margarida Saraiva, R. Duncan Campbell, Antonio AlcamiAbstract:The genetic variability of nine genes in 12 isolates and strains of Ectromelia virus, which causes a smallpox-like disease (mousepox) in mice, was determined and allows for classification of Ectromelia viruses. The low genetic variability suggests that evolutionary pressure maintains the activity of immunomodulatory genes in natural poxvirus infections.
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Inhibition of Type 1 Cytokine–mediated Inflammation by a Soluble CD30 Homologue Encoded by Ectromelia (Mousepox) Virus
The Journal of experimental medicine, 2002Co-Authors: Margarida Saraiva, Philip Smith, Padraic G. Fallon, Antonio AlcamiAbstract:CD30 is up-regulated in several human diseases and viral infections but its role in immune regulation is poorly understood. Here, we report the expression of a functional soluble CD30 homologue, viral CD30 (vCD30), encoded by Ectromelia (mousepox) virus, a poxvirus that causes a severe disease related to human smallpox. We show that vCD30 is a 12-kD secreted protein that not only binds CD30L with high affinity and prevents its interaction with CD30, but it also induces reverse signaling in cells expressing CD30L. vCD30 blocked the generation of interferon gamma-producing cells in vitro and was a potent inhibitor of T helper cell (Th)1- but not Th2-mediated inflammation in vivo. The finding of a CD30 homologue encoded by Ectromelia virus suggests a role for CD30 in antiviral defense. Characterization of the immunological properties of vCD30 has uncovered a role of CD30-CD30L interactions in the generation of inflammatory responses.
R. Mark L. Buller - One of the best experts on this subject based on the ideXlab platform.
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EVM005: an Ectromelia-encoded protein with dual roles in NF-κB inhibition and virulence.
PLoS pathogens, 2014Co-Authors: Nicholas Van Buuren, R. Mark L. Buller, Scott Parker, Jill Schriewer, Kristin Burles, Ninad Mehta, Michele BarryAbstract:Poxviruses contain large dsDNA genomes encoding numerous open reading frames that manipulate cellular signalling pathways and interfere with the host immune response. The NF-κB signalling cascade is an important mediator of innate immunity and inflammation, and is tightly regulated by ubiquitination at several key points. A critical step in NF-κB activation is the ubiquitination and degradation of the inhibitor of kappaB (IκBα), by the cellular SCFβ-TRCP ubiquitin ligase complex. We show here that upon stimulation with TNFα or IL-1β, Orthopoxvirus-infected cells displayed an accumulation of phosphorylated IκBα, indicating that NF-κB activation was inhibited during poxvirus infection. Ectromelia virus is the causative agent of lethal mousepox, a natural disease that is fatal in mice. Previously, we identified a family of four Ectromelia virus genes (EVM002, EVM005, EVM154 and EVM165) that contain N-terminal ankyrin repeats and C-terminal F-box domains that interact with the cellular SCF ubiquitin ligase complex. Since degradation of IκBα is catalyzed by the SCFβ-TRCP ubiquitin ligase, we investigated the role of the Ectromelia virus ankyrin/F-box protein, EVM005, in the regulation of NF-κB. Expression of Flag-EVM005 inhibited both TNFα- and IL-1β-stimulated IκBα degradation and p65 nuclear translocation. Inhibition of the NF-κB pathway by EVM005 was dependent on the F-box domain, and interaction with the SCF complex. Additionally, Ectromelia virus devoid of EVM005 was shown to inhibit NF-κB activation, despite lacking the EVM005 open reading frame. Finally, Ectromelia virus devoid of EVM005 was attenuated in both A/NCR and C57BL/6 mouse models, indicating that EVM005 is required for virulence and immune regulation in vivo.
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Ectromelia virus infections of mice as a model to support the licensure of anti-orthopoxvirus therapeutics.
Viruses, 2010Co-Authors: Scott Parker, Akbar M. Siddiqui, George R. Painter, Jill Schriewer, R. Mark L. BullerAbstract:The absence of herd immunity to orthopoxviruses and the concern that variola or monkeypox viruses could be used for bioterroristic activities has stimulated the development of therapeutics and safer prophylactics. One major limitation in this process is the lack of accessible human orthopoxvirus infections for clinical efficacy trials; however, drug licensure can be based on orthopoxvirus animal challenge models as described in the “Animal Efficacy Rule”. One such challenge model uses Ectromelia virus, an orthopoxvirus, whose natural host is the mouse and is the etiological agent of mousepox. The genetic similarity of Ectromelia virus to variola and monkeypox viruses, the common features of the resulting disease, and the convenience of the mouse as a laboratory animal underscores its utility in the study of orthopoxvirus pathogenesis and in the development of therapeutics and prophylactics. In this review we outline how mousepox has been used as a model for smallpox. We also discuss mousepox in the context of mouse strain, route of infection, infectious dose, disease progression, and recovery from infection.
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Ectromelia Virus Inhibitor of Complement Enzymes Protects Intracellular Mature Virus and Infected Cells from Mouse Complement
Journal of virology, 2010Co-Authors: Elizabeth A. Moulton, Nanhai Chen, R. Mark L. Buller, Paula Bertram, John P. AtkinsonAbstract:Poxviruses produce complement regulatory proteins to subvert the host's immune response. Similar to the human pathogen variola virus, Ectromelia virus has a limited host range and provides a mouse model where the virus and the host's immune response have coevolved. We previously demonstrated that multiple components (C3, C4, and factor B) of the classical and alternative pathways are required to survive Ectromelia virus infection. Complement's role in the innate and adaptive immune responses likely drove the evolution of a virus-encoded virulence factor that regulates complement activation. In this study, we characterized the Ectromelia virus inhibitor of complement enzymes (EMICE). Recombinant EMICE regulated complement activation on the surface of CHO cells, and it protected complement-sensitive intracellular mature virions (IMV) from neutralization in vitro. It accomplished this by serving as a cofactor for the inactivation of C3b and C4b and by dissociating the catalytic domain of the classical pathway C3 convertase. Infected murine cells initiated synthesis of EMICE within 4 to 6 h postinoculation. The levels were sufficient in the supernatant to protect the IMV, upon release, from complement-mediated neutralization. EMICE on the surface of infected murine cells also reduced complement activation by the alternative pathway. In contrast, classical pathway activation by high-titer antibody overwhelmed EMICE's regulatory capacity. These results suggest that EMICE's role is early during infection when it counteracts the innate immune response. In summary, Ectromelia virus produced EMICE within a few hours of an infection, and EMICE in turn decreased complement activation on IMV and infected cells.
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Primary naive and interleukin-2-activated natural killer cells do not support efficient Ectromelia virus replication.
The Journal of general virology, 2008Co-Authors: April Keim Parker, Nanhai Chen, Wayne M. Yokoyama, John A Corbett, R. Mark L. BullerAbstract:Natural killer (NK) cells are known for their ability to lyse tumour cell targets. Studies of infections by a number of viruses, including poxviruses and herpesviruses, have demonstrated that NK cells are vital for recovery from these infections. Little is known of the ability of viruses to infect and complete a productive replication cycle within NK cells. Even less is known concerning the effect of infection on NK cell biology. This study investigated the ability of Ectromelia virus (ECTV) to infect NK cells in vitro and in vivo. Following ECTV infection, NK cell gamma interferon (IFN-gamma) production was diminished and infected cells ceased proliferating and lost viability. ECTV infection of NK cells led to early and late virus gene expression and visualization of immature and mature virus particles, but no detectable increase in viable progeny virus. It was not unexpected that early gene expression occurred in infected NK cells, as the complete early transcription system is packaged within the virions. The detection of the secreted early virus-encoded immunomodulatory proteins IFN-gamma-binding protein and Ectromelia inhibitor of complement enzymes (EMICE) in NK cell culture supernatants suggests that even semi-permissive infection may permit immunomodulation of the local environment.
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The genomic sequence of Ectromelia virus, the causative agent of mousepox.
Virology, 2003Co-Authors: Nanhai Chen, R. Mark L. Buller, Maria I. Danila, Zehua Feng, Chunlin Wang, Xiaosi Han, Elliot J. Lefkowitz, Chris UptonAbstract:Ectromelia virus is the causative agent of mousepox, an acute exanthematous disease of mouse colonies in Europe, Japan, China, and the U.S. The Moscow, Hampstead, and NIH79 strains are the most thoroughly studied with the Moscow strain being the most infectious and virulent for the mouse. In the late 1940s mousepox was proposed as a model for the study of the pathogenesis of smallpox and generalized vaccinia in humans. Studies in the last five decades from a succession of investigators have resulted in a detailed description of the virologic and pathologic disease course in genetically susceptible and resistant inbred and out-bred mice. We report the DNA sequence of the left-hand end, the predicted right-hand terminal repeat, and central regions of the genome of the Moscow strain of Ectromelia virus (approximately 177,500 bp), which together with the previously sequenced right-hand end, yields a genome of 209,771 bp. We identified 175 potential genes specifying proteins of between 53 and 1924 amino acids, and 29 regions containing sequences related to genes predicted in other poxviruses, but unlikely to encode for functional proteins in Ectromelia virus. The translated protein sequences were compared with the protein database for structure/function relationships, and these analyses were used to investigate poxvirus evolution and to attempt to explain at the cellular and molecular level the well-characterized features of the Ectromelia virus natural life cycle.
Nicholas Van Buuren - One of the best experts on this subject based on the ideXlab platform.
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Ectromelia virus encodes a family of ankyrin f box proteins that regulate nfκb
Virology, 2014Co-Authors: Kristin Burles, Nicholas Van Buuren, Michele BarryAbstract:A notable feature of poxviruses is their ability to inhibit the antiviral response, including the nuclear factor kappa B (NFκB) pathway. NFκB is a transcription factor that is sequestered in the cytoplasm until cell stimulation, and relies on the SCF (Skp1, culllin-1, F-box) ubiquitin ligase to target its inhibitor, IκBα, for degradation. IκBα is recruited to the SCF by the F-box domain-containing protein βTrCP. Here, we show that Ectromelia virus, the causative agent of mousepox, encodes four F-box-containing proteins, EVM002, EVM005, EVM154, and EVM165, all of which contain Ankyrin (Ank) domains. The Ank/F-box proteins inhibit NFκB nuclear translocation, and this inhibition is dependent on the F-box domain. We also demonstrate that EVM002, EVM005, EVM154, and EVM165 prevent IκBα degradation, suggesting that they target the SCF. This study identifies a new mechanism by which Ectromelia virus inhibits NFκB.
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Ectromelia virus encodes a family of Ankyrin/F-box proteins that regulate NFκB
Virology, 2014Co-Authors: Kristin Burles, Nicholas Van Buuren, Michele BarryAbstract:A notable feature of poxviruses is their ability to inhibit the antiviral response, including the nuclear factor kappa B (NFκB) pathway. NFκB is a transcription factor that is sequestered in the cytoplasm until cell stimulation, and relies on the SCF (Skp1, culllin-1, F-box) ubiquitin ligase to target its inhibitor, IκBα, for degradation. IκBα is recruited to the SCF by the F-box domain-containing protein βTrCP. Here, we show that Ectromelia virus, the causative agent of mousepox, encodes four F-box-containing proteins, EVM002, EVM005, EVM154, and EVM165, all of which contain Ankyrin (Ank) domains. The Ank/F-box proteins inhibit NFκB nuclear translocation, and this inhibition is dependent on the F-box domain. We also demonstrate that EVM002, EVM005, EVM154, and EVM165 prevent IκBα degradation, suggesting that they target the SCF. This study identifies a new mechanism by which Ectromelia virus inhibits NFκB.
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EVM005: an Ectromelia-encoded protein with dual roles in NF-κB inhibition and virulence.
PLoS pathogens, 2014Co-Authors: Nicholas Van Buuren, R. Mark L. Buller, Scott Parker, Jill Schriewer, Kristin Burles, Ninad Mehta, Michele BarryAbstract:Poxviruses contain large dsDNA genomes encoding numerous open reading frames that manipulate cellular signalling pathways and interfere with the host immune response. The NF-κB signalling cascade is an important mediator of innate immunity and inflammation, and is tightly regulated by ubiquitination at several key points. A critical step in NF-κB activation is the ubiquitination and degradation of the inhibitor of kappaB (IκBα), by the cellular SCFβ-TRCP ubiquitin ligase complex. We show here that upon stimulation with TNFα or IL-1β, Orthopoxvirus-infected cells displayed an accumulation of phosphorylated IκBα, indicating that NF-κB activation was inhibited during poxvirus infection. Ectromelia virus is the causative agent of lethal mousepox, a natural disease that is fatal in mice. Previously, we identified a family of four Ectromelia virus genes (EVM002, EVM005, EVM154 and EVM165) that contain N-terminal ankyrin repeats and C-terminal F-box domains that interact with the cellular SCF ubiquitin ligase complex. Since degradation of IκBα is catalyzed by the SCFβ-TRCP ubiquitin ligase, we investigated the role of the Ectromelia virus ankyrin/F-box protein, EVM005, in the regulation of NF-κB. Expression of Flag-EVM005 inhibited both TNFα- and IL-1β-stimulated IκBα degradation and p65 nuclear translocation. Inhibition of the NF-κB pathway by EVM005 was dependent on the F-box domain, and interaction with the SCF complex. Additionally, Ectromelia virus devoid of EVM005 was shown to inhibit NF-κB activation, despite lacking the EVM005 open reading frame. Finally, Ectromelia virus devoid of EVM005 was attenuated in both A/NCR and C57BL/6 mouse models, indicating that EVM005 is required for virulence and immune regulation in vivo.
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Ectromelia Virus Encodes a Novel Family of F-Box Proteins That Interact with the SCF Complex
Journal of virology, 2008Co-Authors: Nicholas Van Buuren, Brianne Couturier, Yue Xiong, Michele BarryAbstract:Poxviruses are notorious for encoding multiple proteins that regulate cellular signaling pathways, including the ubiquitin-proteasome system. Bioinformatics indicated that Ectromelia virus, the causative agent of lethal mousepox, encoded four proteins, EVM002, EVM005, EVM154, and EVM165, containing putative F-box domains. In contrast to cellular F-box proteins, the Ectromelia virus proteins contain C-terminal F-box domains in conjunction with N-terminal ankyrin repeats, a combination that has not been previously reported for cellular proteins. These observations suggested that the Ectromelia virus F-box proteins interact with SCF (Skp1, cullin-1, and F-box) ubiquitin ligases. We focused our studies on EVM005, since this protein had only one ortholog in cowpox virus. Using mass spectrometry, we identified cullin-1 as a binding partner for EVM005, and this interaction was confirmed by overexpression of hemagglutinin (HA)-cullin-1. During infection, Flag-EVM005 and HA-cullin-1 colocalized to distinct cellular bodies. Significantly, EVM005 coprecipitated with endogenous Skp1, cullin-1, and Roc1 and associated with conjugated ubiquitin, suggesting that EVM005 interacted with the components of a functional ubiquitin ligase. Interaction of EVM005 with cullin-1 and Skp1 was abolished upon deletion of the F-box, indicating that the F-box played a crucial role in interaction with the SCF complex. Additionally, EVM002 and EVM154 interacted with Skp1 and conjugated ubiquitin, suggesting that Ectromelia virus encodes multiple F-box-containing proteins that regulate the SCF complex. Our results indicate that Ectromelia virus has evolved multiple proteins that interact with the SCF complex.
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Ectromelia virus btb kelch proteins evm150 and evm167 interact with cullin 3 based ubiquitin ligases
Virology, 2008Co-Authors: Brianne A. Wilton, Nicholas Van Buuren, Yue Xiong, Stephanie Campbell, Robyn Garneau, Manabu Furukawa, Michele BarryAbstract:Cellular proteins containing BTB and kelch domains have been shown to function as adapters for the recruitment of substrates to cullin-3-based ubiquitin ligases. Poxviruses are the only family of viruses known to encode multiple BTB/kelch proteins, suggesting that poxviruses may modulate the ubiquitin pathway through interaction with cullin-3. Ectromelia virus encodes four BTB/kelch proteins and one BTB-only protein. Here we demonstrate that two of the Ectromelia virus-encoded BTB/kelch proteins, EVM150 and EVM167, interacted with cullin-3. Similar to cellular BTB proteins, the BTB domain of EVM150 and EVM167 was necessary and sufficient for cullin-3 interaction. During infection, EVM150 and EVM167 localized to discrete cytoplasmic regions, which co-localized with cullin-3. Furthermore, EVM150 and EVM167 co-localized and interacted with conjugated ubiquitin, as demonstrated by confocal microscopy and co-immunoprecipitation. Our findings suggest that the Ectromelia virus-encoded BTB/kelch proteins, EVM150 and EVM167, interact with cullin-3 potentially functioning to recruit unidentified substrates for ubiquitination.
Chris Upton - One of the best experts on this subject based on the ideXlab platform.
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an Ectromelia virus profilin homolog interacts with cellular tropomyosin and viral a type inclusion protein
Virology Journal, 2007Co-Authors: Christine Butlercole, Mary J Wagner, Melissa Da Silva, Gordon D Brown, Robert D Burke, Chris UptonAbstract:Background Profilins are critical to cytoskeletal dynamics in eukaryotes; however, little is known about their viral counterparts. In this study, a poxviral profilin homolog, Ectromelia virus strain Moscow gene 141 (ECTV-PH), was investigated by a variety of experimental and bioinformatics techniques to characterize its interactions with cellular and viral proteins.
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The genomic sequence of Ectromelia virus, the causative agent of mousepox.
Virology, 2003Co-Authors: Nanhai Chen, R. Mark L. Buller, Maria I. Danila, Zehua Feng, Chunlin Wang, Xiaosi Han, Elliot J. Lefkowitz, Chris UptonAbstract:Ectromelia virus is the causative agent of mousepox, an acute exanthematous disease of mouse colonies in Europe, Japan, China, and the U.S. The Moscow, Hampstead, and NIH79 strains are the most thoroughly studied with the Moscow strain being the most infectious and virulent for the mouse. In the late 1940s mousepox was proposed as a model for the study of the pathogenesis of smallpox and generalized vaccinia in humans. Studies in the last five decades from a succession of investigators have resulted in a detailed description of the virologic and pathologic disease course in genetically susceptible and resistant inbred and out-bred mice. We report the DNA sequence of the left-hand end, the predicted right-hand terminal repeat, and central regions of the genome of the Moscow strain of Ectromelia virus (approximately 177,500 bp), which together with the previously sequenced right-hand end, yields a genome of 209,771 bp. We identified 175 potential genes specifying proteins of between 53 and 1924 amino acids, and 29 regions containing sequences related to genes predicted in other poxviruses, but unlikely to encode for functional proteins in Ectromelia virus. The translated protein sequences were compared with the protein database for structure/function relationships, and these analyses were used to investigate poxvirus evolution and to attempt to explain at the cellular and molecular level the well-characterized features of the Ectromelia virus natural life cycle.
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Analysis of host response modifier ORFs of Ectromelia virus, the causative agent of mousepox.
Virus research, 2000Co-Authors: Nanhai Chen, R. Mark L. Buller, Erika M. Wall, Chris UptonAbstract:From the right-hand end of the Ectromelia virus (strain Moscow) genome, 32318 bps have been sequenced, and characterized to include a total of 18 open reading frames (ORFs) and six regions which apparently no longer code for functional proteins. At least six of the ORFs appear to be involved in blocking the inflammatory/immune host response to infection, and therefore probably contribute significantly to the virulence of this virus in its natural host, the mouse. One of these genes encoded an isolog of the poxvirus chemokine binding protein, and was shown to be the most abundant protein secreted from Ectromelia virus infected cells. Two regions were found to have significant similarity to poxvirus genes encoding tumor necrosis factor (TNF) binding proteins. Both are distinct from cytokine response modifier (crm)B and crmC but only one is predicted to encode a functional TNF binding protein. A novel similarity between the C-terminal domain of poxvirus TNF binding proteins and several other poxvirus proteins is also presented. The results are discussed in the context of Ectromelia virus pathogenesis of mice.
