The Experts below are selected from a list of 252 Experts worldwide ranked by ideXlab platform
Gisela Wengler - One of the best experts on this subject based on the ideXlab platform.
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the ns 3 Nonstructural Protein of flaviviruses contains an rna triphosphatase activity
Virology, 1993Co-Authors: Gisela WenglerAbstract:Abstract The genome of flaviviruses consists of an infectious single-stranded RNA molecule which contains a type 1 cap structure at the 5′-terminus. The cap is synthesized by RNA triphosphatase, guanylyltransferase and methyltransferase. Since flaviviruses replicate in the cytoplasm, it can be assumed that these functions are performed by virus-coded Proteins. We previously showed that subtilisin treatment of membranes isolated from cells infected with the West Nile flavivirus results in release of a 50 kDa molecular weight fragment of the Viral Nonstructural Protein NS 3. This so-called p50-S Protein contains the residue gly (16B) of NS 3 at the amino-terminus and represents an RNA-stimulated NTPase. In the present report we present experimental evidence which indicates that the p50-S Protein also contains the active site of an RNA triphosphatase. The activity specifically cleaves the β,γ-triphosphate bond at the 5′-terminus of RNA. The localization of NS 3 Protein sequence elements with known functions indicates that this multifunctional Protein contains a protease in the amino-terminal part, a helicase in the central region and the RNA triphosphatase in the carboxy-terminal domain. An amino acid sequence element which may be involved in recognition of the 5′-terminal RNA triphosphate is tentatively identified. A homologous element may be present in the vaccinia virus-coded RNA triphosphatase.
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The NS 3 Nonstructural Protein of flaviviruses contains an RNA triphosphatase activity
Virology, 1993Co-Authors: Gisela WenglerAbstract:The genome of flaviviruses consists of an infectious single-stranded RNA molecule which contains a type 1 cap structure at the 5'-terminus. The cap is synthesized by RNA triphosphatase, guanylyltransferase and methyltransferase. Since flaviviruses replicate in the cytoplasm, it can be assumed that these functions are performed by virus-coded Proteins. We previously showed that subtilisin treatment of membranes isolated from cells infected with the West Nile flavivirus results in release of a 50 kDa molecular weight fragment of the Viral Nonstructural Protein NS 3. This so-called p50-S Protein contains the residue gly (168) of NS 3 at the amino-terminus and represents an RNA-stimulated NTPase. In the present report we present experimental evidence which indicates that the p50-S Protein also contains the active site of an RNA triphosphatase. The activity specifically cleaves the β,γ-triphosphate bond at the 5'-terminus of RNA. The localization of NS 3 Protein sequence elements with known functions indicates that this multifunctional Protein contains a protease in the amino-terminal part, a helicase in the central region and the RNA triphosphatase in the carboxy-terminal domain. An amino acid sequence element which may be involved in recognition of the 5'-terminal RNA triphosphate is tentatively identified. A homologous element may be present in the vaccinia virus-coded RNA triphosphatase. © 1993 Academic Press, Inc.
Sailen Barik - One of the best experts on this subject based on the ideXlab platform.
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2 5 oligoadenylate synthetase like Protein inhibits respiratory syncytial virus replication and is targeted by the Viral Nonstructural Protein 1
Journal of Virology, 2015Co-Authors: Jayeeta Dhar, Rolando Cuevas, Ramansu Goswami, Saumendra N Sarkar, Sailen BarikAbstract:2′-5′-Oligoadenylate synthetase-like Protein (OASL) is an interferon-inducible antiViral Protein. Here we describe differential inhibitory activities of human OASL and the two mouse OASL homologs against respiratory syncytial virus (RSV) replication. Interestingly, Nonstructural Protein 1 (NS1) of RSV promoted proteasome-dependent degradation of specific OASL isoforms. We conclude that OASL acts as a cellular antiViral Protein and that RSV NS1 suppresses this function to evade cellular innate immunity and allow virus growth.
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2′-5′-Oligoadenylate Synthetase-Like Protein Inhibits Respiratory Syncytial Virus Replication and Is Targeted by the Viral Nonstructural Protein 1
Journal of Virology, 2015Co-Authors: Jayeeta Dhar, Rolando Cuevas, Ramansu Goswami, Saumendra N Sarkar, Sailen BarikAbstract:2′-5′-Oligoadenylate synthetase-like Protein (OASL) is an interferon-inducible antiViral Protein. Here we describe differential inhibitory activities of human OASL and the two mouse OASL homologs against respiratory syncytial virus (RSV) replication. Interestingly, Nonstructural Protein 1 (NS1) of RSV promoted proteasome-dependent degradation of specific OASL isoforms. We conclude that OASL acts as a cellular antiViral Protein and that RSV NS1 suppresses this function to evade cellular innate immunity and allow virus growth.
Jayeeta Dhar - One of the best experts on this subject based on the ideXlab platform.
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2 5 oligoadenylate synthetase like Protein inhibits respiratory syncytial virus replication and is targeted by the Viral Nonstructural Protein 1
Journal of Virology, 2015Co-Authors: Jayeeta Dhar, Rolando Cuevas, Ramansu Goswami, Saumendra N Sarkar, Sailen BarikAbstract:2′-5′-Oligoadenylate synthetase-like Protein (OASL) is an interferon-inducible antiViral Protein. Here we describe differential inhibitory activities of human OASL and the two mouse OASL homologs against respiratory syncytial virus (RSV) replication. Interestingly, Nonstructural Protein 1 (NS1) of RSV promoted proteasome-dependent degradation of specific OASL isoforms. We conclude that OASL acts as a cellular antiViral Protein and that RSV NS1 suppresses this function to evade cellular innate immunity and allow virus growth.
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2′-5′-Oligoadenylate Synthetase-Like Protein Inhibits Respiratory Syncytial Virus Replication and Is Targeted by the Viral Nonstructural Protein 1
Journal of Virology, 2015Co-Authors: Jayeeta Dhar, Rolando Cuevas, Ramansu Goswami, Saumendra N Sarkar, Sailen BarikAbstract:2′-5′-Oligoadenylate synthetase-like Protein (OASL) is an interferon-inducible antiViral Protein. Here we describe differential inhibitory activities of human OASL and the two mouse OASL homologs against respiratory syncytial virus (RSV) replication. Interestingly, Nonstructural Protein 1 (NS1) of RSV promoted proteasome-dependent degradation of specific OASL isoforms. We conclude that OASL acts as a cellular antiViral Protein and that RSV NS1 suppresses this function to evade cellular innate immunity and allow virus growth.
Hongyan Chen - One of the best experts on this subject based on the ideXlab platform.
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Nonstructural Protein pns12 of rice dwarf virus is a principal regulator for Viral replication and infection in its insect vector
Virus Research, 2015Co-Authors: Qian Chen, Hongyan ChenAbstract:Abstract Plant reoviruses are thought to replicate and assemble within cytoplasmic structures called viroplasms. The molecular mechanisms underling the formation of the viroplasm during infection of rice dwarf virus (RDV), a plant reovirus, in its leafhopper vector cells remain poorly understood. Viral Nonstructural Protein Pns12 forms viroplasm-like inclusions in the absence of Viral infection, suggesting that the viroplasm matrix is basically composed of Pns12. Here, we demonstrated that core capsid Protein P3 and Nonstructural Protein Pns11 were recruited in the viroplasm by direct interaction with Pns12, whereas Nonstructural Protein Pns6 was recruited through interaction with Pns11. The introduction of dsRNA from Pns12 gene into cultured insect vector cells or intact insect strongly inhibited such viroplasm formation, preventing efficient Viral spread in the leafhopper in vitro and in vivo . Thus, Nonstructural Protein Pns12 of RDV is a principal regulator for Viral replication and infection in its insect vector.
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assembly of viroplasms by Viral Nonstructural Protein pns9 is essential for persistent infection of rice gall dwarf virus in its insect vector
Virus Research, 2015Co-Authors: Limin Zheng, Hongyan ChenAbstract:Abstract Rice gall dwarf virus (RGDV), a plant reovirus, is transmitted by leafhopper vector Recilia dorsalis in a persistent-propagative manner. In a sequential study of RGDV infection of its insect vector, the virus initially infected the filter chamber epithelium, then directly crossed the basal lamina into the visceral muscles, from where it spread throughout the entire midgut and hindgut. Finally, RGDV spread into the salivary glands. During RGDV infection of the continuous cultured cells of R. dorsalis , viroplasm that was mainly comprised of Viral Nonstructural Protein Pns9 was formed and acted as the site of Viral replication and assembly of progeny virions. Knockdown of Pns9 expression in cultured insect vector cells using synthesized dsRNAs from the Pns9 gene strongly inhibited viroplasm formation and Viral infection. The microinjection of dsRNAs from the Pns9 gene strongly abolished viroplasm formation in the initially infected filter chamber epithelium and prevented Viral spread into leafhopper visceral muscles. These results indicated that the assembly of viroplasms was essential for the persistent infection and spread of RGDV in its insect vector.
Zheng Xing - One of the best experts on this subject based on the ideXlab platform.
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synaptogyrin 2 promotes replication of a novel tick borne bunyavirus through interacting with Viral Nonstructural Protein nss
Journal of Biological Chemistry, 2016Co-Authors: Xian Qi, Yan Zhang, Xiaodong Wu, Mifang Liang, Chuan Li, Dexin Li, Carol J Cardona, Zheng XingAbstract:Abstract Synaptogyrin-2 is a non-neuronal member of the synaptogyrin family involved in synaptic vesicle biogenesis and trafficking. Little is known about the function of synaptogyrin-2. Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease characterized by high fever, thrombocytopenia, and leukocytopenia with high mortality, caused by a novel tick-borne phlebovirus in the family Bunyaviridae. Our previous studies have shown that the Viral Nonstructural Protein NSs forms inclusion bodies (IBs) that are involved in Viral immune evasion, as well as Viral RNA replication. In this study, we sought to elucidate the mechanism by which NSs formed the IBs, a lipid droplet-based structure confirmed by NSs co-localization with perilipin A and adipose differentiation-related Protein (ADRP). Through a high throughput screening, we identified synaptogyrin-2 to be highly up-regulated in response to SFTS bunyavirus (SFTSV) infection and to be a promoter of Viral replication. We demonstrated that synaptogyrin-2 interacted with NSs and was translocated into the IBs, which were reconstructed from lipid droplets into large structures in infection. Viral RNA replication decreased, and infectious virus titers were lowered significantly when synaptogyrin-2 was silenced in specific shRNA-expressing cells, which correlated with the reduced number of the large IBs restructured from regular lipid droplets. We hypothesize that synaptogyrin-2 is essential to promoting the formation of the IBs to become virus factories for Viral RNA replication through its interaction with NSs. These findings unveil the function of synaptogyrin-2 as an enhancer in Viral infection.
