scholarly journals The respiratory syncytial virus nucleoprotein–RNA complex forms a left-handed helical nucleocapsid

2013 ◽  
Vol 94 (8) ◽  
pp. 1734-1738 ◽  
Author(s):  
Saskia E. Bakker ◽  
Stéphane Duquerroy ◽  
Marie Galloux ◽  
Colin Loney ◽  
Edward Conner ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Protein Interactions ◽  
Genome Replication ◽  
N Protein ◽  
Left Handed ◽  
Syncytial Virus ◽  
Complex Forms ◽  
Nucleoprotein N ◽  
Rna Complex ◽  
Negative Sense

Respiratory syncytial virus (RSV) is an important human pathogen. Its nucleocapsid (NC), which comprises the negative sense RNA viral genome coated by the viral nucleoprotein N, is a critical assembly that serves as template for both mRNA synthesis and genome replication. We have previously described the X-ray structure of an NC-like structure: a decameric ring formed of N-RNA that mimics one turn of the helical NC. In the absence of experimental data we had hypothesized that the NC helix would be right-handed, as the N–N contacts in the ring appeared to more easily adapt to that conformation. We now unambiguously show that the RSV NC is a left-handed helix. We further show that the contacts in the ring can be distorted to maintain key N–N-protein interactions in a left-handed helix, and discuss the implications of the resulting atomic model of the helical NC for viral replication and transcription.

scholarly journals In vitro trackable assembly of RNA-specific nucleocapsids of the respiratory syncytial virus

2019 ◽  
Vol 295 (3) ◽  
pp. 883-895 ◽  
Author(s):  
Yunrong Gao ◽  
Dongdong Cao ◽  
Hyunjun Max Ahn ◽  
Anshuman Swain ◽  
Shaylan Hill ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Rna Synthesis ◽  
Genomic Rnas ◽  
Viral Rnas ◽  
N Protein ◽  
Syncytial Virus ◽  
Nucleoprotein N ◽  
Negative Sense ◽  
Transcription And Replication

The templates for transcription and replication by respiratory syncytial virus (RSV) polymerase are helical nucleocapsids (NCs), formed by viral RNAs that are encapsidated by the nucleoprotein (N). Proper NC assembly is vital for RSV polymerase to engage the RNA template for RNA synthesis. Previous studies of NCs or nucleocapsid-like particles (NCLPs) from RSV and other nonsegmented negative-sense RNA viruses have provided insights into the overall NC architecture. However, in these studies, the RNAs were either random cellular RNAs or average viral genomic RNAs. An in-depth mechanistic understanding of NCs has been hampered by lack of an in vitro assay that can track NC or NCLP assembly. Here we established a protocol to obtain RNA-free N protein (N0) and successfully demonstrated the utility of a new assay for tracking assembly of N with RNA oligonucleotides into NCLPs. We discovered that the efficiency of the NCLP (N–RNA) assembly depends on the length and sequence of the RNA incorporated into NCLPs. This work provides a framework to generate purified N0 and incorporate it with RNA into NCLPs in a controllable manner. We anticipate that our assay for in vitro trackable assembly of RSV-specific nucleocapsids may enable in-depth mechanistic analyses of this process.

Crystal Structure of a Nucleocapsid-Like Nucleoprotein-RNA Complex of Respiratory Syncytial Virus

Science ◽  
2009 ◽  
Vol 326 (5957) ◽  
pp. 1279-1283 ◽  
Author(s):  
Rajiv G. Tawar ◽  
Stéphane Duquerroy ◽  
Clemens Vonrhein ◽  
Paloma F. Varela ◽  
Laurence Damier-Piolle ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Respiratory Syncytial Virus ◽  
Rna Virus ◽  
Three Dimensional ◽  
Detailed Model ◽  
Syncytial Virus ◽  
Key Sites ◽  
Microscopy Data ◽  
Nucleoprotein N ◽  
Rna Complex

The respiratory syncytial virus (RSV) is an important human pathogen, yet neither a vaccine nor effective therapies are available to treat infection. To help elucidate the replication mechanism of this RNA virus, we determined the three-dimensional (3D) crystal structure at 3.3 Å resolution of a decameric, annular ribonucleoprotein complex of the RSV nucleoprotein (N) bound to RNA. This complex mimics one turn of the viral helical nucleocapsid complex, which serves as template for viral RNA synthesis. The RNA wraps around the protein ring, with seven nucleotides contacting each N subunit, alternating rows of four and three stacked bases that are exposed and buried within a protein groove, respectively. Combined with electron microscopy data, this structure provides a detailed model for the RSV nucleocapsid, in which the bases are accessible for readout by the viral polymerase. Furthermore, the nucleoprotein structure highlights possible key sites for drug targeting.

scholarly journals Structure of the paramyxovirus parainfluenza virus 5 nucleoprotein–RNA complex

2015 ◽  
Vol 112 (14) ◽  
pp. E1792-E1799 ◽  
Author(s):  
Maher Alayyoubi ◽  
George P. Leser ◽  
Christopher A. Kors ◽  
Robert A. Lamb
Keyword(s):  
Ring Cavity ◽  
Polymerase Activity ◽  
Parainfluenza Virus ◽  
Genome Packaging ◽  
N Protein ◽  
Major Disruption ◽  
Parainfluenza Virus 5 ◽  
Nucleoprotein N ◽  
Rna Complex ◽  
Negative Sense

Parainfluenza virus 5 (PIV5) is a member of theParamyxoviridaefamily of membrane-enveloped viruses with a negative-sense RNA genome that is packaged and protected by long filamentous nucleocapsid-helix structures (RNPs). These RNPs, consisting of ∼2,600 protomers of nucleocapsid (N) protein, form the template for viral transcription and replication. We have determined the 3D X-ray crystal structure of the nucleoprotein (N)-RNA complex from PIV5 to 3.11-Å resolution. The structure reveals a 13-mer nucleocapsid ring whose diameter, cavity, and pitch/height dimensions agree with EM data from early studies on theParamyxovirinaesubfamily of native RNPs, indicating that it closely represents one-turn in the building block of the RNP helices. The PIV5-N nucleocapsid ring encapsidates a nuclease resistant 78-nt RNA strand in its positively charged groove formed between the N-terminal (NTD) and C-terminal (CTD) domains of its successive N protomers. Six nucleotides precisely are associated with each N protomer, with alternating three-base-in three-base-out conformation. The binding of six nucleotides per protomer is consistent with the “rule of six” that governs the genome packaging of theParamyxovirinaesubfamily of viruses. PIV5-N protomer subdomains are very similar in structure to the previously solved Nipah-N structure, but with a difference in the angle between NTD/CTD at the RNA hinge region. Based on the Nipah-N structure we modeled a PIV5-N open conformation in which the CTD rotates away from the RNA strand into the inner spacious nucleocapsid-ring cavity. This rotation would expose the RNA for the viral polymerase activity without major disruption of the nucleocapsid structure.

scholarly journals siRNA-Mediated Simultaneous Regulation of the Cellular Innate Immune Response and Human Respiratory Syncytial Virus Replication

Biomolecules ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 165 ◽  
Author(s):  
María Martín-Vicente ◽  
Salvador Resino ◽  
Isidoro Martínez
Keyword(s):  
Immune Response ◽  
Respiratory Syncytial Virus ◽  
Virus Replication ◽  
Innate Immune Response ◽  
Human Respiratory Syncytial Virus ◽  
Innate Immune ◽  
Viral Fusion ◽  
Small Interfering Rnas ◽  
Syncytial Virus ◽  
Nucleoprotein N

Human respiratory syncytial virus (HRSV) infection is a common cause of severe lower respiratory tract diseases such as bronchiolitis and pneumonia. Both virus replication and the associated inflammatory immune response are believed to be behind these pathologies. So far, no vaccine or effective treatment is available for this viral infection. With the aim of finding new strategies to counteract HRSV replication and modulate the immune response, specific small interfering RNAs (siRNAs) were generated targeting the mRNA coding for the viral fusion (F) protein or nucleoprotein (N), or for two proteins involved in intracellular immune signaling, which are named tripartite motif-containing protein 25 (TRIM25) and retinoic acid-inducible gene-I (RIG-I). Furthermore, two additional bispecific siRNAs were designed that silenced F and TRIM25 (TRIM25/HRSV-F) or N and RIG-I (RIG-I/HRSV-N) simultaneously. All siRNAs targeting N or F, but not those silencing TRIM25 or RIG-I alone, significantly reduced viral titers. However, while siRNAs targeting F inhibited only the expression of the F mRNA and protein, the siRNAs targeting N led to a general inhibition of viral mRNA and protein expression. The N-targeting siRNAs also induced a drastic decrease in the expression of genes of the innate immune response. These results show that both virus replication and the early innate immune response can be regulated by targeting distinct viral products with siRNAs, which may be related to the different role of each protein in the life cycle of the virus.

Immunovirological studies on human respiratory syncytial virus structural proteins

1986 ◽  
Vol 32 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Michel Trudel ◽  
Francine Nadon ◽  
Cécile Séguin ◽  
Simone Ghoubril ◽  
Pierre Payment ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Fusion Protein ◽  
Neutralizing Antibodies ◽  
Sodium Dodecyl ◽  
Human Respiratory Syncytial Virus ◽  
Structural Proteins ◽  
Membrane Glycoproteins ◽  
Protein Dimer ◽  
Syncytial Virus ◽  
Nucleoprotein N

Immunovirological studies suggest that human respiratory syncytial virus may well be composed of five structural proteins as are other members of the Paramyxoviridae family: the two external membrane glycoproteins H (90 000) and Fo (F1, 49 000; F2, 20 000; disulfide linked), the internal membrane protein M (34 000), the nucleoprotein N (42 000), and a protein (78 000) designated P that could be the equivalent of the polymerase of the morbillivirus and paramyxovirus genus. Neutralizing monoclonal antibodies showed, by immunoprecipitation and immunoblotting, that the fusion protein carries neutralizing epitopes. One monoclonal antibody, which shows a high neutralizing titer, immunoblotted directly with the F1 fragment (49 000) of the fusion protein. Analysis in mice of the immunogenicity of the structural proteins separated on sodium dodecyl sulphate gels indicated that, under our conditions, only the fusion protein dimer Fo and its F1 fragment were capable of inducing neutralizing antibodies.

scholarly journals Unravelling the complexities of respiratory syncytial virus RNA synthesis

2006 ◽  
Vol 87 (7) ◽  
pp. 1805-1821 ◽  
Author(s):  
Vanessa M. Cowton ◽  
David R. McGivern ◽  
Rachel Fearns
Keyword(s):  
Respiratory Syncytial Virus ◽  
Vaccine Development ◽  
Virus Genome ◽  
Genome Replication ◽  
Promoter Regions ◽  
Genome Expression ◽  
Virus Rna ◽  
A Genome ◽  
Genome Rnas ◽  
Syncytial Virus

Human respiratory syncytial virus (RSV) is the leading cause of paediatric respiratory disease and is the focus of antiviral- and vaccine-development programmes. These goals have been aided by an understanding of the virus genome architecture and the mechanisms by which it is expressed and replicated. RSV is a member of the order Mononegavirales and, as such, has a genome consisting of a single strand of negative-sense RNA. At first glance, transcription and genome replication appear straightforward, requiring self-contained promoter regions at the 3′ ends of the genome and antigenome RNAs, short cis-acting elements flanking each of the genes and one polymerase. However, from these minimal elements, the virus is able to generate an array of capped, methylated and polyadenylated mRNAs and encapsidated antigenome and genome RNAs, all in the appropriate ratios to facilitate virus replication. The apparent simplicity of genome expression and replication is a consequence of considerable complexity in the polymerase structure and its cognate cis-acting sequences; here, our understanding of mechanisms by which the RSV polymerase proteins interact with signals in the RNA template to produce different RNA products is reviewed.

Immunological Characterization of Respiratory Syncytial Virus N Protein Epitopes Recognized by Human Cytotoxic T Lymphocytes

2007 ◽  
Vol 20 (3) ◽  
pp. 399-406 ◽  
Author(s):  
Chiara Terrosi ◽  
Giuseppa Di Genova ◽  
Gianni Gori Savellini ◽  
Pierpaolo Correale ◽  
Patrizia Blardi ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
T Lymphocytes ◽  
Cytotoxic T Lymphocytes ◽  
Immunological Characterization ◽  
N Protein ◽  
Syncytial Virus

scholarly journals The Major Phosphorylation Sites of the Respiratory Syncytial Virus Phosphoprotein Are Dispensable for Virus Replication In Vitro

2002 ◽  
Vol 76 (21) ◽  
pp. 10776-10784 ◽  
Author(s):  
Bin Lu ◽  
Chien-Hui Ma ◽  
Robert Brazas ◽  
Hong Jin
Keyword(s):  
Respiratory Syncytial Virus ◽  
Virus Replication ◽  
Vero Cells ◽  
Phosphorylation Sites ◽  
N Protein ◽  
P Protein ◽  
Infected Cells ◽  
Syncytial Virus

ABSTRACT The phosphoprotein (P protein) of respiratory syncytial virus (RSV) is a key component of the viral RNA-dependent RNA polymerase complex. The protein is constitutively phosphorylated at the two clusters of serine residues (116, 117, and 119 [116/117/119] and 232 and 237 [232/237]). To examine the role of phosphorylation of the RSV P protein in virus replication, these five serine residues were altered to eliminate their phosphorylation potential, and the mutant proteins were analyzed for their functions with a minigenome assay. The reporter gene expression was reduced by 20% when all five phosphorylation sites were eliminated. Mutants with knockout mutations at two phosphorylation sites (S232A/S237A [PP2]) and at five phosphorylation sites (S116L/S117R/S119L/S232A/S237A [PP5]) were introduced into the infectious RSV A2 strain. Immunoprecipitation of 33Pi-labeled infected cells showed that P protein phosphorylation was reduced by 80% for rA2-PP2 and 95% for rA2-PP5. The interaction between the nucleocapsid (N) protein and P protein was reduced in rA2-PP2- and rA2-PP5-infected cells by 30 and 60%, respectively. Although the two recombinant viruses replicated well in Vero cells, rA2-PP2 and, to a greater extent, rA2-PP5, replicated poorly in HEp-2 cells. Virus budding from the infected HEp-2 cells was affected by dephosphorylation of P protein, because the majority of rA2-PP5 remained cell associated. In addition, rA2-PP5 was also more attenuated than rA2-PP2 in replication in the respiratory tracts of mice and cotton rats. Thus, our data suggest that although the major phosphorylation sites of RSV P protein are dispensable for virus replication in vitro, phosphorylation of P protein is required for efficient virus replication in vitro and in vivo.

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