Critical role for G3BP1 in infectious bursal disease virus (IBDV)-induced stress granule formation and viral replication

2020 ◽  
Vol 248 ◽  
pp. 108806
Author(s):  
Dianzheng Zhao ◽  
Jiaxin Li ◽  
Yongqiang Wang ◽  
Xiaoqi Li ◽  
Li Gao ◽  
...  
Keyword(s):  
Viral Replication ◽  
Disease Virus ◽  
Infectious Bursal Disease Virus ◽  
Critical Role ◽  
Stress Granule ◽  
Infectious Bursal Disease ◽  
Granule Formation ◽  
Induced Stress ◽  
Bursal Disease

scholarly journals Nuclear Factor NF45 Interacts with Viral Proteins of Infectious Bursal Disease Virus and Inhibits Viral Replication

2010 ◽  
Vol 84 (20) ◽  
pp. 10592-10605 ◽  
Author(s):  
Ruth L. O. Stricker ◽  
Sven-Erik Behrens ◽  
Egbert Mundt
Keyword(s):  
Viral Replication ◽  
Disease Virus ◽  
Infectious Bursal Disease Virus ◽  
Molecular Mechanisms ◽  
Viral Proteins ◽  
Infectious Bursal Disease ◽  
Nuclear Factor ◽  
Replication Process ◽  
Bursal Disease ◽  
Infected Cells

ABSTRACT Two of the central issues in developing new strategies to interfere with viral infections concern the identification of cellular proteins involved in viral replication and/or antiviral measures and the dissection of the underlying molecular mechanisms. To gain initial insight into the role of host proteins in the life cycle of infectious bursal disease virus (IBDV), a double-stranded RNA virus, we examined the cellular nuclear factor 45 (NF45). NF45 was previously indicated to be involved in the replication process of other types of RNA viruses. Interestingly, by performing immunofluorescence studies, we found that in IBDV-infected cells the mainly nuclear NF45 accumulated at the sites of viral replication in the cytoplasm. NF45 was shown to specifically colocalize with the viral RNA-dependent RNA polymerase VP1, the capsid protein VP2, and the ribonucleoprotein VP3. Immunoprecipitation experiments indicated protein-protein associations between NF45 and VP1, VP2, and VP3. Expression of the individual VP3 or the combination of expression of VP1 and VP3 did not result in a cytoplasmic accumulation of NF45, which, among other data, showed that recruitment of the cellular protein in infected cells functionally correlates with the viral replication process. Since small interfering RNA(siRNA)-mediated downregulation of NF45 resulted in an approximately 5-fold increase of virus yield, our study suggests that NF45, by association with viral proteins, is part of a yet-uncharacterized cellular defense mechanism against IBDV infections.

scholarly journals Identification and Molecular Characterization of the RNA Polymerase-Binding Motif of Infectious Bursal Disease Virus Inner Capsid Protein VP3

2003 ◽  
Vol 77 (4) ◽  
pp. 2459-2468 ◽  
Author(s):  
Antonio Maraver ◽  
Roberto Clemente ◽  
Jose Francisco Rodríguez ◽  
Eleuterio Lombardo
Keyword(s):  
Rna Polymerase ◽  
Capsid Protein ◽  
Disease Virus ◽  
Infectious Bursal Disease Virus ◽  
Critical Role ◽  
Rnase A ◽  
Infectious Bursal Disease ◽  
Binding Motif ◽  
Bursal Disease

ABSTRACT Infectious bursal disease virus (IBDV), a member of the Birnaviridae family, is the causative agent of one of the most important infectious poultry diseases. Major aspects of the molecular biology of IBDV, such as assembly and replication, are as yet poorly understood. We have previously shown that encapsidation of the putative virus-encoded RNA-dependent RNA polymerase VP1 is mediated by its interaction with the inner capsid protein VP3. Here, we report the characterization of the VP1-VP3 interaction. RNase A treatment of VP1- and VP3-containing extracts does not affect the formation of VP1-VP3 complexes, indicating that formation of the complex requires the establishment of protein-protein interactions. The use of a set of VP3 deletion mutants allowed the mapping of the VP1 binding motif of VP3 within a highly charged 16-amino-acid stretch on the C terminus of VP3. This region of VP3 is sufficient to confer VP1 binding activity when fused to an unrelated protein. Furthermore, a peptide corresponding to the VP1 binding region of VP3 specifically inhibits the formation of VP1-VP3 complexes. The presence of Trojan peptides containing the VP1 binding motif in IBDV-infected cells specifically reduces infective virus production, thus showing that formation of VP1-VP3 complexes plays a critical role in IBDV replication.

scholarly journals Triplet amino acids located at positions 145/146/147 of the RNA polymerase of very virulent infectious bursal disease virus contribute to viral virulence

2014 ◽  
Vol 95 (4) ◽  
pp. 888-897 ◽  
Author(s):  
Li Gao ◽  
Kai Li ◽  
Xiaole Qi ◽  
Honglei Gao ◽  
Yulong Gao ◽  
...  
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Disease Virus ◽  
Infectious Bursal Disease Virus ◽  
Chicken Embryo Fibroblast ◽  
Critical Role ◽  
Infectious Bursal Disease ◽  
Effective Prevention ◽  
Viral Virulence ◽  
Bursal Disease

Infectious bursal disease virus (IBDV) causes an economically significant disease of chickens worldwide. The emergence of very virulent IBDV (vvIBDV) has brought more challenges for effective prevention of this disease. The molecular basis for the virulence of vvIBDV is not fully understood. In this study, 20 IBDV strains were analysed phylogenically and clustered in three branches based on their full-length B segments. The amino acid triplet located at positions 145/146/147 of VP1 was found highly conserved in branch I non-vvIBDVs as asparagine/glutamic acid/glycine (NEG), in branch II vvIBDVs as threonine/glutamic acid/glycine (TEG) and in branch III vvIBDVs as threonine/aspartic acid/asparagine (TDN). Further studies showed that the three amino acids play a critical role in the replication and pathogenicity of vvIBDV. Substitution of the TDN triplet with TEG or NEG reduced viral replication and pathogenicity of the vvIBDV HuB-1 strain in chickens. However, the replication of the attenuated IBDV Gt strain was reduced in chicken embryo fibroblast cells, whilst it was enhanced in the bursa by substituting NEG with TEG or TDN. The exchange of the three amino acids was also found to be capable of affecting the polymerase activity of VP1. The important role of segment B in the pathogenicity of IBDV was confirmed in this study. These results also provided new insights into the mechanism of the virulence of vvIBDVs and may offer new targets for their attenuation to develop potential vaccines using reverse genetics.

scholarly journals The Oligomerization Domain of VP3, the Scaffolding Protein of Infectious Bursal Disease Virus, Plays a Critical Role in Capsid Assembly

2003 ◽  
Vol 77 (11) ◽  
pp. 6438-6449 ◽  
Author(s):  
Antonio Maraver ◽  
Ana Oña ◽  
Fernando Abaitua ◽  
Dolores González ◽  
Roberto Clemente ◽  
...  
Keyword(s):  
Disease Virus ◽  
Infectious Bursal Disease Virus ◽  
Insect Cells ◽  
Critical Role ◽  
Recombinant Baculovirus ◽  
Particle Formation ◽  
Scaffolding Protein ◽  
Infectious Bursal Disease ◽  
Bursal Disease ◽  
Oligomerization Domain

ABSTRACT Infectious bursal disease virus (IBDV) capsids are formed by a single protein layer containing three polypeptides, pVP2, VP2, and VP3. Here, we show that the VP3 protein synthesized in insect cells, either after expression of the complete polyprotein or from a VP3 gene construct, is proteolytically degraded, leading to the accumulation of product lacking the 13 C-terminal residues. This finding led to identification of the VP3 oligomerization domain within a 24-amino-acid stretch near the C-terminal end of the polypeptide, partially overlapping the VP1 binding domain. Inactivation of the VP3 oligomerization domain, by either proteolysis or deletion of the polyprotein gene, abolishes viruslike particle formation. Formation of VP3-VP1 complexes in cells infected with a dual recombinant baculovirus simultaneously expressing the polyprotein and VP1 prevented VP3 proteolysis and led to efficient virus-like particle formation in insect cells.

scholarly journals Epigenetic Upregulation of Chicken MicroRNA-16-5p Expression in DF-1 Cells following Infection with Infectious Bursal Disease Virus (IBDV) Enhances IBDV-Induced Apoptosis and Viral Replication

2019 ◽  
Vol 94 (2) ◽  
Author(s):  
Xueyan Duan ◽  
Mingliang Zhao ◽  
Yongqiang Wang ◽  
Xiaoqi Li ◽  
Hong Cao ◽  
...  
Keyword(s):  
Viral Replication ◽  
Disease Virus ◽  
Infectious Bursal Disease Virus ◽  
B Cell Lymphoma ◽  
Host Cells ◽  
Infectious Bursal Disease ◽  
Caspase 9 ◽  
Antiapoptotic Protein ◽  
Bursal Disease ◽  
Induced Apoptosis

ABSTRACT MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression posttranscriptionally by silencing or degrading their targets and play important roles in the host response to pathogenic infection. Although infectious bursal disease virus (IBDV)-induced apoptosis in host cells has been established, the underlying molecular mechanism is not completely unraveled. Here, we show that infection of DF-1 cells by IBDV induced gga-miR-16-5p (chicken miR-16-5p) expression via demethylation of the pre-miR-16-2 (gga-miR-16-5p precursor) promoter. We found that ectopic expression of gga-miR-16-5p in DF-1 cells enhanced IBDV-induced apoptosis by directly targeting the cellular antiapoptotic protein B-cell lymphoma 2 (Bcl-2), facilitating IBDV replication in DF-1 cells. In contrast, inhibition of endogenous miR-16-5p markedly suppressed apoptosis associated with enhanced Bcl-2 expression, arresting viral replication in DF-1 cells. Furthermore, infection of DF-1 cells with IBDV reduced Bcl-2 expression, and this reduction could be abolished by inhibition of gga-miR-16-5p expression. Moreover, transfection of DF-1 cells with gga-miR-16-5p mimics enhanced IBDV-induced apoptosis associated with increased cytochrome c release and caspase-9 and -3 activation, and inhibition of caspase-3 decreased IBDV growth in DF-1 cells. Thus, epigenetic upregulation of gga-miR-16-5p expression by IBDV infection enhances IBDV-induced apoptosis by targeting the cellular antiapoptotic protein Bcl-2, facilitating IBDV replication in host cells. IMPORTANCE Infectious bursal disease (IBD) is an acute, highly contagious, and immunosuppressive disease in young chickens, causing severe economic losses to stakeholders across the globe. Although IBD virus (IBDV)-induced apoptosis in the host has been established, the underlying mechanism is not very clear. Here, we show that infection of DF-1 cells by IBDV upregulated gga-miR-16-5p expression via demethylation of the pre-miR-16-2 promoter. Overexpression of gga-miR-16-5p enhanced IBDV-induced apoptosis associated with increased cytochrome c release and caspase-9 and -3 activation. Importantly, we found that IBDV infection induced expression of gga-miR-16-5p that triggered apoptosis by targeting Bcl-2, favoring IBDV replication, while inhibition of gga-miR-16-5p in IBDV-infected cells restored Bcl-2 expression, slowing down viral growth, indicating that IBDV induces apoptosis by epigenetic upregulation of gga-miR-16-5p expression. These findings uncover a novel mechanism employed by IBDV for its own benefit, which may be used as a potential target for intervening IBDV infection.

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