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[PMID]:29059239
[Au] Autor:Prasanth KR; Chuang C; Nagy PD
[Ad] Endereço:Department of Plant Pathology, University of Kentucky, Plant Science Building, Lexington, KY, United States of America.
[Ti] Título:Co-opting ATP-generating glycolytic enzyme PGK1 phosphoglycerate kinase facilitates the assembly of viral replicase complexes.
[So] Source:PLoS Pathog;13(10):e1006689, 2017 Oct.
[Is] ISSN:1553-7374
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The intricate interactions between viruses and hosts include exploitation of host cells for viral replication by using many cellular resources, metabolites and energy. Tomato bushy stunt virus (TBSV), similar to other (+)RNA viruses, induces major changes in infected cells that lead to the formation of large replication compartments consisting of aggregated peroxisomal and ER membranes. Yet, it is not known how TBSV obtains the energy to fuel these energy-consuming processes. In the current work, the authors discovered that TBSV co-opts the glycolytic ATP-generating Pgk1 phosphoglycerate kinase to facilitate the assembly of new viral replicase complexes. The recruitment of Pgk1 into the viral replication compartment is through direct interaction with the viral replication proteins. Altogether, we provide evidence that the ATP generated locally within the replication compartment by the co-opted Pgk1 is used to fuel the ATP-requirement of the co-opted heat shock protein 70 (Hsp70) chaperone, which is essential for the assembly of new viral replicase complexes and the activation of functional viral RNA-dependent RNA polymerase. The advantage of direct recruitment of Pgk1 into the virus replication compartment could be that the virus replicase assembly does not need to intensively compete with cellular processes for access to ATP. In addition, local production of ATP within the replication compartment could greatly facilitate the efficiency of Hsp70-driven replicase assembly by providing high ATP concentration within the replication compartment.
[Mh] Termos MeSH primário: Interações Hospedeiro-Patógeno/fisiologia
Fosfoglicerato Quinase/metabolismo
Tombusvirus/crescimento & desenvolvimento
Montagem de Vírus/fisiologia
[Mh] Termos MeSH secundário: RNA Replicase/metabolismo
Saccharomyces cerevisiae
Tabaco/virologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
EC 2.7.2.3 (Phosphoglycerate Kinase); EC 2.7.7.48 (RNA Replicase)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171113
[Lr] Data última revisão:
171113
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171024
[St] Status:MEDLINE
[do] DOI:10.1371/journal.ppat.1006689


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[PMID]:28759634
[Au] Autor:Kovalev N; Inaba JI; Li Z; Nagy PD
[Ad] Endereço:Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America.
[Ti] Título:The role of co-opted ESCRT proteins and lipid factors in protection of tombusviral double-stranded RNA replication intermediate against reconstituted RNAi in yeast.
[So] Source:PLoS Pathog;13(7):e1006520, 2017 Jul.
[Is] ISSN:1553-7374
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Reconstituted antiviral defense pathway in surrogate host yeast is used as an intracellular probe to further our understanding of virus-host interactions and the role of co-opted host factors in formation of membrane-bound viral replicase complexes in protection of the viral RNA against ribonucleases. The inhibitory effect of the RNA interference (RNAi) machinery of S. castellii, which only consists of the two-component DCR1 and AGO1 genes, was measured against tomato bushy stunt virus (TBSV) in wild type and mutant yeasts. We show that deletion of the co-opted ESCRT-I (endosomal sorting complexes required for transport I) or ESCRT-III factors makes TBSV replication more sensitive to the RNAi machinery in yeast. Moreover, the lack of these pro-viral cellular factors in cell-free extracts (CFEs) used for in vitro assembly of the TBSV replicase results in destruction of dsRNA replication intermediate by a ribonuclease at the 60 min time point when the CFE from wt yeast has provided protection for dsRNA. In addition, we demonstrate that co-opted oxysterol-binding proteins and membrane contact sites, which are involved in enrichment of sterols within the tombusvirus replication compartment, are required for protection of viral dsRNA. We also show that phosphatidylethanolamine level influences the formation of RNAi-resistant replication compartment. In the absence of peroxisomes in pex3Δ yeast, TBSV subverts the ER membranes, which provide as good protection for TBSV dsRNA against RNAi or ribonucleases as the peroxisomal membranes in wt yeast. Altogether, these results demonstrate that co-opted protein factors and usurped lipids are exploited by tombusviruses to build protective subcellular environment against the RNAi machinery and possibly other cellular ribonucleases.
[Mh] Termos MeSH primário: Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo
Interferência de RNA
RNA de Cadeia Dupla/genética
RNA Viral/genética
Proteínas de Saccharomyces cerevisiae/metabolismo
Saccharomyces cerevisiae/genética
Saccharomyces cerevisiae/virologia
Tombusvirus/genética
[Mh] Termos MeSH secundário: Complexos Endossomais de Distribuição Requeridos para Transporte/genética
RNA de Cadeia Dupla/metabolismo
RNA Viral/metabolismo
Saccharomyces/genética
Saccharomyces/metabolismo
Saccharomyces cerevisiae/metabolismo
Proteínas de Saccharomyces cerevisiae/genética
Tombusvirus/fisiologia
Replicação Viral
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Endosomal Sorting Complexes Required for Transport); 0 (RNA, Double-Stranded); 0 (RNA, Viral); 0 (Saccharomyces cerevisiae Proteins)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170918
[Lr] Data última revisão:
170918
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170801
[St] Status:MEDLINE
[do] DOI:10.1371/journal.ppat.1006520


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[PMID]:28724762
[Au] Autor:Sherman MB; Kakani K; Rochon D; Jiang W; Voss NR; Smith TJ
[Ad] Endereço:Department of Biochemistry and Molecular Biology, University of Texas Medical Branch at Galveston, Galveston, Texas, USA.
[Ti] Título:Stability of Cucumber Necrosis Virus at the Quasi-6-Fold Axis Affects Zoospore Transmission.
[So] Source:J Virol;91(19), 2017 Oct 01.
[Is] ISSN:1098-5514
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:(CNV) is a member of the genus and has a monopartite positive-sense RNA genome. CNV is transmitted in nature via zoospores of the fungus As with other members of the genus, the CNV capsid swells when exposed to alkaline pH and EDTA. We previously demonstrated that a P73G mutation blocks the virus from zoospore transmission while not significantly affecting replication in plants (K. Kakani, R. Reade, and D. Rochon, J Mol Biol 338:507-517, 2004, https://doi.org/10.1016/j.jmb.2004.03.008). P73 lies immediately adjacent to a putative zinc binding site (M. Li et al., J Virol 87:12166-12175, 2013, https://doi.org/10.1128/JVI.01965-13) that is formed by three icosahedrally related His residues in the N termini of the C subunit at the quasi-6-fold axes. To better understand how this buried residue might affect vector transmission, we determined the cryo-electron microscopy structure of wild-type CNV in the native and swollen state and of the transmission-defective mutant, P73G, under native conditions. With the wild-type CNV, the swollen structure demonstrated the expected expansion of the capsid. However, the zinc binding region at the quasi-6-fold at the ß-annulus axes remained intact. By comparison, the zinc binding region of the P73G mutant, even under native conditions, was markedly disordered, suggesting that the ß-annulus had been disrupted and that this could destabilize the capsid. This was confirmed with pH and urea denaturation experiments in conjunction with electron microscopy analysis. We suggest that the P73G mutation affects the zinc binding and/or the ß-annulus, making it more fragile under neutral/basic pH conditions. This, in turn, may affect zoospore transmission. (CNV), a member of the genus , is transmitted in nature via zoospores of the fungus While a number of plant viruses are transmitted via insect vectors, little is known at the molecular level as to how the viruses are recognized and transmitted. As with many spherical plant viruses, the CNV capsid swells when exposed to alkaline pH and EDTA. We previously demonstrated that a P73G mutation that lies inside the capsid immediately adjacent to a putative zinc binding site (Li et al., J Virol 87:12166-12175, 2013, https://doi.org/10.1128/JVI.01965-13) blocks the virus from zoospore transmission while not significantly affecting replication in plants (K. Kakani, R. Reade, and D. Rochon, J Mol Biol 338:507-517, 2004, https://doi.org/10.1016/j.jmb.2004.03.008). Here, we show that the P73G mutant is less stable than the wild type, and this appears to be correlated with destabilization of the ß-annulus at the icosahedral 3-fold axes. Therefore, the ß-annulus appears not to be essential for particle assembly but is necessary for interactions with the transmission vector.
[Mh] Termos MeSH primário: Proteínas do Capsídeo/ultraestrutura
Esporos Fúngicos/virologia
Tabaco/virologia
Tombusvirus/genética
Tombusvirus/ultraestrutura
Replicação Viral/genética
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Proteínas do Capsídeo/genética
Quitridiomicetos/virologia
Microscopia Crioeletrônica
Doenças das Plantas/virologia
Tombusvirus/patogenicidade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Capsid Proteins)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170926
[Lr] Data última revisão:
170926
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170721
[St] Status:MEDLINE


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[PMID]:28440187
[Au] Autor:Narayanan KB; Han SS
[Ad] Endereço:School of Chemical Engineering, Yeungnam University, 280 Daehak-Ro, Gyeongsan, Gyeongbuk 38541. Korea.
[Ti] Título:Genetic Modifications of Icosahedral Plant Virus-based Nanoparticles for Vaccine and Immunotherapy Applications.
[So] Source:Curr Protein Pept Sci;18(11):1141-1151, 2017 Aug 30.
[Is] ISSN:1875-5550
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Vaccine development is one of the greatest achievements of modern medicine. Vaccines made of live-attenuated pathogens can revert to virulent live strains, which causes safety concerns. On the other hand, the use of purified antigenic components as subunit vaccines is safer, but less effective, as these components induce lower levels of protective immunity. Multiple copy presentation of an antigenic determinant in a well-ordered and well-defined orientation on a nanosized particle can mimic the natural host-pathogen surface interaction to provide antigen stability and immunogenicity similar to that of conventional vaccines with improved safety. The icosahedral symmetry of plant viral capsid based nanoparticles is highly ordered and their multivalent structured protein nanostructures facilitate genetic modifications that result in the display of heterologous epitopes or antigens attached to coat proteins. These recombinant plant virus-based nanoparticles (PVNs) provide platforms for the induction of humoral and cellular immune responses to genetically fused antigens from pathogenic viruses, bacteria, tumors, and toxins in man and animals. Here, we comprehensively review the developments of several recombinant PVNs as prophylactic and/or therapeutic vaccines for the prevention or treatment of several microbial diseases, pathologies, and toxin poisoning.
[Mh] Termos MeSH primário: Doença de Alzheimer/terapia
Vacinas Bacterianas/imunologia
Vacinas Antimaláricas/imunologia
Nanopartículas/química
Vacinas Virais/imunologia
Vírion/imunologia
[Mh] Termos MeSH secundário: Vírus do Mosaico da Alfafa/genética
Vírus do Mosaico da Alfafa/imunologia
Doença de Alzheimer/imunologia
Doença de Alzheimer/patologia
Animais
Antígenos/química
Antígenos/imunologia
Vacinas Bacterianas/administração & dosagem
Vacinas Bacterianas/química
Vacinas Bacterianas/genética
Comovirus/genética
Comovirus/imunologia
Cucumovirus/genética
Cucumovirus/imunologia
Epitopos/química
Epitopos/imunologia
Seres Humanos
Imunoterapia/métodos
Vacinas Antimaláricas/administração & dosagem
Vacinas Antimaláricas/química
Vacinas Antimaláricas/genética
Nanopartículas/administração & dosagem
Tombusviridae/genética
Tombusviridae/imunologia
Tombusvirus/genética
Tombusvirus/imunologia
Vacinas Virais/administração & dosagem
Vacinas Virais/química
Vacinas Virais/genética
Vírion/química
Vírion/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Antigens); 0 (Bacterial Vaccines); 0 (Epitopes); 0 (Malaria Vaccines); 0 (Viral Vaccines)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171106
[Lr] Data última revisão:
171106
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170426
[St] Status:MEDLINE
[do] DOI:10.2174/1389203718666170424153109


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[PMID]:28100609
[Au] Autor:Xu K; Nagy PD
[Ad] Endereço:Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, USA.
[Ti] Título:Sterol Binding by the Tombusviral Replication Proteins Is Essential for Replication in Yeast and Plants.
[So] Source:J Virol;91(7), 2017 Apr 01.
[Is] ISSN:1098-5514
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Membranous structures derived from various organelles are important for replication of plus-stranded RNA viruses. Although the important roles of co-opted host proteins in RNA virus replication have been appreciated for a decade, the equally important functions of cellular lipids in virus replication have been gaining full attention only recently. Previous work with (TBSV) in model host yeast has revealed essential roles for phosphatidylethanolamine and sterols in viral replication. To further our understanding of the role of sterols in tombusvirus replication, in this work we showed that the TBSV p33 and p92 replication proteins could bind to sterols The sterol binding by p33 is supported by cholesterol recognition/interaction amino acid consensus (CRAC) and CARC-like sequences within the two transmembrane domains of p33. Mutagenesis of the critical Y amino acids within the CRAC and CARC sequences blocked TBSV replication in yeast and plant cells. We also showed the enrichment of sterols in the detergent-resistant membrane (DRM) fractions obtained from yeast and plant cells replicating TBSV. The DRMs could support viral RNA synthesis on both the endogenous and exogenous templates. A lipidomic approach showed the lack of enhancement of sterol levels in yeast and plant cells replicating TBSV. The data support the notion that the TBSV replication proteins are associated with sterol-rich detergent-resistant membranes in yeast and plant cells. Together, the results obtained in this study and the previously published results support the local enrichment of sterols around the viral replication proteins that is critical for TBSV replication. One intriguing aspect of viral infections is their dependence on efficient subcellular assembly platforms serving replication, virion assembly, or virus egress via budding out of infected cells. These assembly platforms might involve sterol-rich membrane microdomains, which are heterogeneous and highly dynamic nanoscale structures usurped by various viruses. Here, we demonstrate that TBSV p33 and p92 replication proteins can bind to sterol Mutagenesis analysis of p33 within the CRAC and CARC sequences involved in sterol binding shows the important connection between the abilities of p33 to bind to sterol and to support TBSV replication in yeast and plant cells. Together, the results further strengthen the model that cellular sterols are essential as proviral lipids during viral replication.
[Mh] Termos MeSH primário: Colesterol/química
Protoplastos/virologia
Saccharomyces cerevisiae/virologia
Tombusvirus/fisiologia
Proteínas Virais/química
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Sítios de Ligação
Colesterol/fisiologia
Microdomínios da Membrana/metabolismo
Ligação Proteica
Tabaco/virologia
Proteínas Virais/fisiologia
Replicação Viral
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Viral Proteins); 97C5T2UQ7J (Cholesterol)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170913
[Lr] Data última revisão:
170913
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170120
[St] Status:MEDLINE


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[PMID]:27807229
[Au] Autor:Alam SB; Rochon D
[Ad] Endereço:Faculty of Land and Food Systems, Plant Science Program, University of British Columbia, Vancouver, British Columbia, Canada.
[Ti] Título:Evidence that Hsc70 Is Associated with Cucumber Necrosis Virus Particles and Plays a Role in Particle Disassembly.
[So] Source:J Virol;91(2), 2017 Jan 15.
[Is] ISSN:1098-5514
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Uncoating of a virus particle to expose its nucleic acid is a critical aspect of the viral multiplication cycle, as it is essential for the establishment of infection. In the present study, we investigated the role of plant HSP70 homologs in the uncoating process of Cucumber necrosis virus (CNV), a nonenveloped positive-sense single-stranded RNA [(+)ssRNA] virus having a T=3 icosahedral capsid. We have found through Western blot analysis and mass spectrometry that the HSP70 homolog Hsc70-2 copurifies with CNV particles. Virus overlay and immunogold labeling assays suggest that Hsc70-2 is physically bound to virions. Furthermore, trypsin digestion profiles suggest that the bound Hsc70-2 is partially protected by the virus, indicating an intimate association with particles. In investigating a possible role of Hsc70-2 in particle disassembly, we showed that particles incubated with Hsp70/Hsc70 antibody produce fewer local lesions than those incubated with prebleed control antibody on Chenopodium quinoa In conjunction, CNV virions purified using CsCl and having undetectable amounts of Hsc70-2 produce fewer local lesions. We also have found that plants with elevated levels of HSP70/Hsc70 produce higher numbers of local lesions following CNV inoculation. Finally, incubation of recombinant Nicotiana benthamiana Hsc70-2 with virus particles in vitro leads to conformational changes or partial disassembly of capsids as determined by transmission electron microscopy, and particles are more sensitive to chymotrypsin digestion. This is the first report suggesting that a cellular Hsc70 chaperone is involved in disassembly of a plant virus. IMPORTANCE: Virus particles must disassemble and release their nucleic acid in order to establish infection in a cell. Despite the importance of disassembly in the ability of a virus to infect its host, little is known about this process, especially in the case of nonenveloped spherical RNA viruses. Previous work has shown that host HSP70 homologs play multiple roles in the CNV infection cycle. We therefore examined the potential role of these cellular components in the CNV disassembly process. We show that the HSP70 family member Hsc70-2 is physically associated with CNV virions and that HSP70 antibody reduces the ability of CNV to establish infection. Statistically significantly fewer lesions are produced when virions having undetectable HSc70-2 are used as an inoculum. Finally incubation of Hsc70-2 with CNV particles results in conformational changes in particles. Taken together, our data point to an important role of the host factor Hsc70-2 in CNV disassembly.
[Mh] Termos MeSH primário: Cucumis sativus/metabolismo
Cucumis sativus/virologia
Proteínas de Choque Térmico HSP70/metabolismo
Doenças das Plantas/virologia
Tombusvirus/fisiologia
Vírion/fisiologia
Desenvelopamento do Vírus
[Mh] Termos MeSH secundário: Capsídeo/metabolismo
Proteínas do Capsídeo/metabolismo
Fenótipo
Ligação Proteica
Tombusvirus/ultraestrutura
Vírion/isolamento & purificação
Vírion/ultraestrutura
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Capsid Proteins); 0 (HSP70 Heat-Shock Proteins)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170714
[Lr] Data última revisão:
170714
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161104
[St] Status:MEDLINE


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[PMID]:27637297
[Au] Autor:Rubino L; Guaragnella N; Giannattasio S
[Ad] Endereço:Istituto di Protezione Sostenibile delle Piante, CNR, UOS Bari, Via Amendola 165/A, 70126 Bari, Italy. Electronic address: luisa.rubino@cnr.it.
[Ti] Título:Heterologous expression of carnation Italian ringspot virus p36 protein enhances necrotic cell death in response to acetic acid in Saccharomyces cerevisiae.
[So] Source:Mech Ageing Dev;161(Pt B):255-261, 2017 Jan.
[Is] ISSN:1872-6216
[Cp] País de publicação:Ireland
[La] Idioma:eng
[Ab] Resumo:A universal feature of the replication of positive-strand RNA viruses is the association with intracellular membranes. Carnation Italian ringspot virus (CIRV) replication in plants occurs in vesicles derived from the mitochondrial outer membrane. The product encoded by CIRV ORF1, p36, is required for targeting the virus replication complex to the outer mitochondrial membrane both in plant and yeast cells. Here the yeast Saccharomyces cerevisiae was used as a model host to study the effect of CIRV p36 on cell survival and death. It was shown that p36 does not promote cell death, but decreases cell growth rate. In addition, p36 changed the nature of acetic acid-induced cell death in yeast by increasing the number of cells dying by necrosis with concomitant decrease of the number of cells dying by programmed cell death, as judged by measurements of phosphatidylserine externalization. The tight association of p36 to membranes was not affected by acetic acid treatment, thus confirming the peculiar and independent interaction of CIRV p36 with mitochondria in yeast. This work proved yeast as an invaluable model organism to study both the mitochondrial determinants of the type of cell death in response to stress and the molecular pathogenesis of (+)RNA viruses.
[Mh] Termos MeSH primário: Ácido Acético/farmacologia
Membranas Mitocondriais/metabolismo
Saccharomyces cerevisiae/metabolismo
Tombusvirus/genética
Proteínas Virais/metabolismo
[Mh] Termos MeSH secundário: Morte Celular/efeitos dos fármacos
Morte Celular/genética
Saccharomyces cerevisiae/genética
Tombusvirus/metabolismo
Proteínas Virais/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Viral Proteins); Q40Q9N063P (Acetic Acid)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170810
[Lr] Data última revisão:
170810
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160918
[St] Status:MEDLINE


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[PMID]:27026525
[Au] Autor:Fernández de Castro I; Fernández JJ; Barajas D; Nagy PD; Risco C
[Ad] Endereço:Cell Structure Laboratory, Centro Nacional de Biotecnología (CNB-CSIC), Campus de Cantoblanco, Madrid 28049, Spain crisco@cnb.csic.es ifernandez@cnb.csic.es.
[Ti] Título:Three-dimensional imaging of the intracellular assembly of a functional viral RNA replicase complex.
[So] Source:J Cell Sci;130(1):260-268, 2017 Jan 01.
[Is] ISSN:1477-9137
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Positive-strand RNA viruses, which can be devastating pathogens in humans, animals and plants, replicate their genomes on intracellular membranes. Here, we describe the three-dimensional ultrastructural organization of a tombusvirus replicase in yeast, a valuable model for exploring virus-host interactions. We visualized the intracellular distribution of a viral replicase protein using metal-tagging transmission electron microscopy, a highly sensitive nanotechnology whose full potential remains to be developed. These three-dimensional images show how viral replicase molecules are organized when they are incorporated into the active domains of the intracellular replication compartment. Our approach provides a means to study protein activation mechanisms in cells and to identify targets for new antiviral compounds.
[Mh] Termos MeSH primário: Imagem Tridimensional
Espaço Intracelular/virologia
RNA Replicase/metabolismo
RNA Viral/metabolismo
Tombusvirus/fisiologia
Montagem de Vírus
[Mh] Termos MeSH secundário: Anticorpos/metabolismo
Metalotioneína/metabolismo
Modelos Biológicos
RNA de Cadeia Dupla/metabolismo
Saccharomyces cerevisiae/ultraestrutura
Saccharomyces cerevisiae/virologia
Tombusvirus/ultraestrutura
Tomografia
Replicação Viral
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Antibodies); 0 (RNA, Double-Stranded); 0 (RNA, Viral); 9038-94-2 (Metallothionein); EC 2.7.7.48 (RNA Replicase)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170804
[Lr] Data última revisão:
170804
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160331
[St] Status:MEDLINE
[do] DOI:10.1242/jcs.181586


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[PMID]:27760128
[Au] Autor:Xu K; Nagy PD
[Ad] Endereço:Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America.
[Ti] Título:Enrichment of Phosphatidylethanolamine in Viral Replication Compartments via Co-opting the Endosomal Rab5 Small GTPase by a Positive-Strand RNA Virus.
[So] Source:PLoS Biol;14(10):e2000128, 2016 Oct.
[Is] ISSN:1545-7885
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Positive-strand RNA viruses build extensive membranous replication compartments to support replication and protect the virus from antiviral responses by the host. These viruses require host factors and various lipids to form viral replication complexes (VRCs). The VRCs built by Tomato bushy stunt virus (TBSV) are enriched with phosphatidylethanolamine (PE) through a previously unknown pathway. To unravel the mechanism of PE enrichment within the TBSV replication compartment, in this paper, the authors demonstrate that TBSV co-opts the guanosine triphosphate (GTP)-bound active form of the endosomal Rab5 small GTPase via direct interaction with the viral replication protein. Deletion of Rab5 orthologs in a yeast model host or expression of dominant negative mutants of plant Rab5 greatly decreases TBSV replication and prevents the redistribution of PE to the sites of viral replication. We also show that enrichment of PE in the viral replication compartment is assisted by actin filaments. Interestingly, the closely related Carnation Italian ringspot virus, which replicates on the boundary membrane of mitochondria, uses a similar strategy to the peroxisomal TBSV to hijack the Rab5-positive endosomes into the viral replication compartments. Altogether, usurping the GTP-Rab5-positive endosomes allows TBSV to build a PE-enriched viral replication compartment, which is needed to support peak-level replication. Thus, the Rab family of small GTPases includes critical host factors assisting VRC assembly and genesis of the viral replication compartment.
[Mh] Termos MeSH primário: Endossomos/enzimologia
Fosfatidiletanolaminas/metabolismo
Replicação Viral
Proteínas rab5 de Ligação ao GTP/metabolismo
[Mh] Termos MeSH secundário: Compartimento Celular
Tombusvirus/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Phosphatidylethanolamines); 39382-08-6 (phosphatidylethanolamine); EC 3.6.5.2 (rab5 GTP-Binding Proteins)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170523
[Lr] Data última revisão:
170523
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161021
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pbio.2000128


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[PMID]:27711201
[Au] Autor:Kontra L; Csorba T; Tavazza M; Lucioli A; Tavazza R; Moxon S; Tisza V; Medzihradszky A; Turina M; Burgyán J
[Ad] Endereço:National Agricultural Research and Innovation Centre, Agricultural Biotechnology Institute, Gödöllo, Hungary.
[Ti] Título:Distinct Effects of p19 RNA Silencing Suppressor on Small RNA Mediated Pathways in Plants.
[So] Source:PLoS Pathog;12(10):e1005935, 2016 Oct.
[Is] ISSN:1553-7374
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:RNA silencing is one of the main defense mechanisms employed by plants to fight viruses. In change, viruses have evolved silencing suppressor proteins to neutralize antiviral silencing. Since the endogenous and antiviral functions of RNA silencing pathway rely on common components, it was suggested that viral suppressors interfere with endogenous silencing pathway contributing to viral symptom development. In this work, we aimed to understand the effects of the tombusviral p19 suppressor on endogenous and antiviral silencing during genuine virus infection. We showed that ectopically expressed p19 sequesters endogenous small RNAs (sRNAs) in the absence, but not in the presence of virus infection. Our presented data question the generalized model in which the sequestration of endogenous sRNAs by the viral suppressor contributes to the viral symptom development. We further showed that p19 preferentially binds the perfectly paired ds-viral small interfering RNAs (vsiRNAs) but does not select based on their sequence or the type of the 5' nucleotide. Finally, co-immunoprecipitation of sRNAs with AGO1 or AGO2 from virus-infected plants revealed that p19 specifically impairs vsiRNA loading into AGO1 but not AGO2. Our findings, coupled with the fact that p19-expressing wild type Cymbidium ringspot virus (CymRSV) overcomes the Nicotiana benthamiana silencing based defense killing the host, suggest that AGO1 is the main effector of antiviral silencing in this host-virus combination.
[Mh] Termos MeSH primário: Doenças das Plantas/genética
Doenças das Plantas/virologia
Proteínas de Plantas/metabolismo
Tabaco/genética
Tabaco/virologia
Tombusvirus/genética
Proteínas Virais/genética
[Mh] Termos MeSH secundário: Northern Blotting
Western Blotting
Ensaio de Desvio de Mobilidade Eletroforética
Sequenciamento de Nucleotídeos em Larga Escala
Imunoprecipitação
Plantas Geneticamente Modificadas
RNA de Plantas/genética
RNA Interferente Pequeno/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (P19 protein, tomato bushy stunt virus); 0 (Plant Proteins); 0 (RNA, Plant); 0 (RNA, Small Interfering); 0 (Viral Proteins)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170601
[Lr] Data última revisão:
170601
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161007
[St] Status:MEDLINE
[do] DOI:10.1371/journal.ppat.1005935



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