The Dicistroviridae is a virus family that includes many insect pathogens.These viruses contain a positive-sense RNA genome that is replicated by the virally encoded RNA-dependent RNA polymerase(RdRP)also named 3D^(po...The Dicistroviridae is a virus family that includes many insect pathogens.These viruses contain a positive-sense RNA genome that is replicated by the virally encoded RNA-dependent RNA polymerase(RdRP)also named 3D^(pol).Compared with the Picornaviridae RdRPs such as poliovirus(PV)3D^(pol),the Dicistroviridae representative Israeli acute paralysis virus(IAPV)3D^(pol) has an additional N-terminal extension(NE)region that is about 40-residue in length.To date,both the structure and catalytic mechanism of the Dicistroviridae RdRP have remain elusive.Here we reported crystal structures of two truncated forms of IAPV 3D^(pol),namelyΔ85 andΔ40,both missing the NE region,and the 3D^(pol) protein in these structures exhibited three conformational states.The palm and thumb domains of these IAPV 3D^(pol) structures are largely consistent with those of the PV 3D^(pol) structures.However,in all structures,the RdRP fingers domain is partially disordered,while different conformations of RdRP substructures and interactions between them are also present.In particular,a large-scale conformational change occurred in the motif B-middle finger region in one protein chain of theΔ40 structure,while a previously documented alternative conformation of motif A was observed in all IAPV structures.These experimental data on one hand show intrinsic conformational variances of RdRP substructures,and on the other hand suggest possible contribution of the NE region in proper RdRP folding in IAPV.展开更多
An about 1.5kb functional domain sequence of GCRV-RdRp gene was obtained by using RT-PCR amplification.The amplified fragment was cloned into T7 promoted prokaryotic expression system pRSET-C vector and then was trans...An about 1.5kb functional domain sequence of GCRV-RdRp gene was obtained by using RT-PCR amplification.The amplified fragment was cloned into T7 promoted prokaryotic expression system pRSET-C vector and then was transformed into CaCl 2 treated TOP10F’and BL21(DE3)pLysS competent cells respectively.The recombinants were detected with restriction enzyme digestion and further confirmed the interest insert by sequencing pRSET-C/GCRV-RdRp plasmid,which was in frame with the N-terminal tag and in the proper orientation.SDS-PAGE revealed that the highly expressed fusion protein is produced by inducing with l nm IPTG,and its molecular weight is around 55kD,which is the right size corresponding to the predicted value.It indicated the fused protein was produced in the form of inclusion body with its yield remained steadly more than 60% of total bacterial protein. It also showed that the expressed protein was able to bind immunologically to rabbit anti-GCRV-VP2 serum.展开更多
A large number of deaths have been caused by the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)worldwide,turning it into a serious and momentous threat to public health.This study tends to contribute to t...A large number of deaths have been caused by the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)worldwide,turning it into a serious and momentous threat to public health.This study tends to contribute to the development of effective treatment strategies through a computational approach,investigating the mechanisms in relation to the binding and subsequent inhibition of SARS-CoV-2 ribonucleic acid(RNA)-dependent RNA polymerase(RdRp).Molecular docking was performed to screen six naturally occurring molecules with antineoplastic properties(Ellipticine,Ecteinascidin,Homoharringtonine,Dolastatin 10,Halichondrin,and Plicamycin).Absorption,distribution,metabolism,and excretion(ADME)investigation was also conducted to analyze the druglike properties of these compounds.The docked results have clearly shown binding of ligands to the SARS-CoV-2 RdRp protein.Interestingly,all ligands were found to obey Lipinski’s rule of five.These results provide a basis for repurposing and using molecules,derived from plants and animals,as a potential treatment for the coronavirus disease 2019(COVID-19)infection as they could be effective therapeutics for the same.展开更多
Despite the global decline in the severity of the coronavirus disease 2019 (COVID-19) cases, the disease stillrepresents a major concern to the relevant scientific and medical communities. The primary concern of drug ...Despite the global decline in the severity of the coronavirus disease 2019 (COVID-19) cases, the disease stillrepresents a major concern to the relevant scientific and medical communities. The primary concern of drug scientists,virologists, and other concerned specialists in this respect is to find ready-to-use suitable and potent anticoronaviraltherapies that are broadly effective against the different species/strains of the coronaviruses in general, not only againstthe current and previous coronaviruses (e.g., the recently-appeared severe acute respiratory syndrome coronavirus 2“SARS-CoV-2”), i.e., effective antiviral agents for treatment and/or prophylaxis of any coronaviral infections, includingthose of the coming ones from the next species and strains (if any). As an expert in this field, I tried, in this up-to-dateperspective “viewpoint” article, to evaluate the suitability and applicability of using the currently-availableanticoronaviral agents for the next coronavirus diseases (COVIDs) and coronaviral pandemics, highlighting the mostimportant general guidelines that should be considered in the next pandemics from the therapeutic points of view.展开更多
Rabbit hemorrhagic disease virus(RHDV)is a member of the Caliciviridae family and cannot be propagated in vitro,which has impeded the progress of investigating its replication mechanism.Construction of an RHDV replico...Rabbit hemorrhagic disease virus(RHDV)is a member of the Caliciviridae family and cannot be propagated in vitro,which has impeded the progress of investigating its replication mechanism.Construction of an RHDV replicon system has recently provided a platform for exploring RHDV replication in host cells.Here,aided by this replicon system and using two-step affinity purification,we purified the RHDV replicase and identified its associated host factors.We identified rabbit nucleolin(NCL)as a physical link,which mediating the interaction between other RNA-dependent RNA polymerase(Rd Rp)-related host proteins and the viral replicase Rd Rp.We found that the overexpression or knockdown of NCL significantly increased or severely impaired RHDV replication in RK-13 cells,respectively.NCL was identified to directly interact with RHDV Rd Rp,p16,and p23.Furthermore,NCL knockdown severely impaired the binding of Rd Rp to Rd Rp-related host factors.Collectively,these results indicate that the host protein NCL is essential for RHDV replication and acts as a physical link between viral replicase and host proteins.展开更多
基金supported by the National Natural Science Foundation of China (31802147 to G.L.,31572471,31811530276 to C.H.)National Key Research and Development Program of China (2018YFA0507200 to P.G.and G.L.)+3 种基金the Agricultural Science and Technology Innovation Program (CAAS-ASTIP-2023-IBFC to C.H.)the Creative Research Group Program of Natural Science Foundation of Hubei Province (2022CFA021 to P.G.)the Central Public-Interest Scientific Institution Basal Research Fund (Y2021YJ25 to C.H.)Key Biosafety Science and Technology Program of Hubei Jiangxia Laboratory (JXBS001 to P.G.).
文摘The Dicistroviridae is a virus family that includes many insect pathogens.These viruses contain a positive-sense RNA genome that is replicated by the virally encoded RNA-dependent RNA polymerase(RdRP)also named 3D^(pol).Compared with the Picornaviridae RdRPs such as poliovirus(PV)3D^(pol),the Dicistroviridae representative Israeli acute paralysis virus(IAPV)3D^(pol) has an additional N-terminal extension(NE)region that is about 40-residue in length.To date,both the structure and catalytic mechanism of the Dicistroviridae RdRP have remain elusive.Here we reported crystal structures of two truncated forms of IAPV 3D^(pol),namelyΔ85 andΔ40,both missing the NE region,and the 3D^(pol) protein in these structures exhibited three conformational states.The palm and thumb domains of these IAPV 3D^(pol) structures are largely consistent with those of the PV 3D^(pol) structures.However,in all structures,the RdRP fingers domain is partially disordered,while different conformations of RdRP substructures and interactions between them are also present.In particular,a large-scale conformational change occurred in the motif B-middle finger region in one protein chain of theΔ40 structure,while a previously documented alternative conformation of motif A was observed in all IAPV structures.These experimental data on one hand show intrinsic conformational variances of RdRP substructures,and on the other hand suggest possible contribution of the NE region in proper RdRP folding in IAPV.
文摘An about 1.5kb functional domain sequence of GCRV-RdRp gene was obtained by using RT-PCR amplification.The amplified fragment was cloned into T7 promoted prokaryotic expression system pRSET-C vector and then was transformed into CaCl 2 treated TOP10F’and BL21(DE3)pLysS competent cells respectively.The recombinants were detected with restriction enzyme digestion and further confirmed the interest insert by sequencing pRSET-C/GCRV-RdRp plasmid,which was in frame with the N-terminal tag and in the proper orientation.SDS-PAGE revealed that the highly expressed fusion protein is produced by inducing with l nm IPTG,and its molecular weight is around 55kD,which is the right size corresponding to the predicted value.It indicated the fused protein was produced in the form of inclusion body with its yield remained steadly more than 60% of total bacterial protein. It also showed that the expressed protein was able to bind immunologically to rabbit anti-GCRV-VP2 serum.
文摘A large number of deaths have been caused by the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)worldwide,turning it into a serious and momentous threat to public health.This study tends to contribute to the development of effective treatment strategies through a computational approach,investigating the mechanisms in relation to the binding and subsequent inhibition of SARS-CoV-2 ribonucleic acid(RNA)-dependent RNA polymerase(RdRp).Molecular docking was performed to screen six naturally occurring molecules with antineoplastic properties(Ellipticine,Ecteinascidin,Homoharringtonine,Dolastatin 10,Halichondrin,and Plicamycin).Absorption,distribution,metabolism,and excretion(ADME)investigation was also conducted to analyze the druglike properties of these compounds.The docked results have clearly shown binding of ligands to the SARS-CoV-2 RdRp protein.Interestingly,all ligands were found to obey Lipinski’s rule of five.These results provide a basis for repurposing and using molecules,derived from plants and animals,as a potential treatment for the coronavirus disease 2019(COVID-19)infection as they could be effective therapeutics for the same.
文摘Despite the global decline in the severity of the coronavirus disease 2019 (COVID-19) cases, the disease stillrepresents a major concern to the relevant scientific and medical communities. The primary concern of drug scientists,virologists, and other concerned specialists in this respect is to find ready-to-use suitable and potent anticoronaviraltherapies that are broadly effective against the different species/strains of the coronaviruses in general, not only againstthe current and previous coronaviruses (e.g., the recently-appeared severe acute respiratory syndrome coronavirus 2“SARS-CoV-2”), i.e., effective antiviral agents for treatment and/or prophylaxis of any coronaviral infections, includingthose of the coming ones from the next species and strains (if any). As an expert in this field, I tried, in this up-to-dateperspective “viewpoint” article, to evaluate the suitability and applicability of using the currently-availableanticoronaviral agents for the next coronavirus diseases (COVIDs) and coronaviral pandemics, highlighting the mostimportant general guidelines that should be considered in the next pandemics from the therapeutic points of view.
基金sponsored by Shanghai Sailing Program(20YF1457700)the National Natural Science Foundation of China(32000109 and 31672572)the China Postdoctoral Science Foundation(2019M660885 and 2021T140718)
文摘Rabbit hemorrhagic disease virus(RHDV)is a member of the Caliciviridae family and cannot be propagated in vitro,which has impeded the progress of investigating its replication mechanism.Construction of an RHDV replicon system has recently provided a platform for exploring RHDV replication in host cells.Here,aided by this replicon system and using two-step affinity purification,we purified the RHDV replicase and identified its associated host factors.We identified rabbit nucleolin(NCL)as a physical link,which mediating the interaction between other RNA-dependent RNA polymerase(Rd Rp)-related host proteins and the viral replicase Rd Rp.We found that the overexpression or knockdown of NCL significantly increased or severely impaired RHDV replication in RK-13 cells,respectively.NCL was identified to directly interact with RHDV Rd Rp,p16,and p23.Furthermore,NCL knockdown severely impaired the binding of Rd Rp to Rd Rp-related host factors.Collectively,these results indicate that the host protein NCL is essential for RHDV replication and acts as a physical link between viral replicase and host proteins.
