scholarly journals The genome segment B encoding the RNA-dependent RNA polymerase protein VP1 of very virulent infectious bursal disease virus (IBDV) is phylogenetically distinct from that of all other IBDV strains

2001 ◽  
Vol 146 (12) ◽  
pp. 2481-2492 ◽  
Author(s):  
M. R. Islam ◽  
K. Zierenberg ◽  
H. Müller
Keyword(s):  
Rna Polymerase ◽  
Disease Virus ◽  
Infectious Bursal Disease Virus ◽  
Genome Segment ◽  
Infectious Bursal Disease ◽  
Rna Dependent Rna Polymerase ◽  
Bursal Disease

scholarly journals VP1 of infectious bursal disease virus is an RNA-dependent RNA polymerase

2004 ◽  
Vol 85 (8) ◽  
pp. 2221-2229 ◽  
Author(s):  
Ursula I. von Einem ◽  
Alexander E. Gorbalenya ◽  
Horst Schirrmeier ◽  
Sven-Erik Behrens ◽  
Tobias Letzel ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Rna Polymerase ◽  
Disease Virus ◽  
Infectious Bursal Disease Virus ◽  
Infectious Bursal Disease ◽  
Coding Region ◽  
Rdrp Activity ◽  
Rna Dependent Rna Polymerase ◽  
Double Stranded Rna ◽  
Bursal Disease

Segment B of the bisegmented, double-stranded RNA genome of infectious bursal disease virus (IBDV) encodes the viral protein VP1. This has been presumed to represent the RNA-dependent RNA polymerase (RdRp) as it contains motifs that are typical for the RdRp of plus-strand RNA viruses. Here it is demonstrated that baculovirus-expressed wild-type but not motif A mutated VP1 acts as an RdRp on IBDV-specific RNA templates. Thus, on a plus-strand IBDV segment A cRNA template, minus-strand synthesis occurred in such a way that a covalently linked double-stranded RNA product was generated (by a ‘copy-back’ mechanism). Importantly, enzyme activity was observed only with templates that comprised the 3′ non-coding region of plus-strand RNAs transcribed from IBDV segments A and B, indicating template specificity. RdRp activity was shown to have a temperature optimum of 37 °C and required magnesium ions for enzyme activity. Thus, it has been demonstrated unequivocally that VP1 represents the RdRp of IBDV.

In VitroExpression and Monoclonal Antibody of RNA-Dependent RNA Polymerase for Infectious Bursal Disease Virus

2006 ◽  
Vol 25 (11) ◽  
pp. 646-653 ◽  
Author(s):  
Xiaojuan Zheng ◽  
Lianlian Hong ◽  
Yifei Li ◽  
Junqing Guo ◽  
Gaiping Zhang ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Rna Polymerase ◽  
Disease Virus ◽  
Infectious Bursal Disease Virus ◽  
Infectious Bursal Disease ◽  
Rna Dependent Rna Polymerase ◽  
Bursal Disease

scholarly journals VP1, the Putative RNA-Dependent RNA Polymerase of Infectious Bursal Disease Virus, Forms Complexes with the Capsid Protein VP3, Leading to Efficient Encapsidation into Virus-Like Particles

1999 ◽  
Vol 73 (8) ◽  
pp. 6973-6983 ◽  
Author(s):  
Eleuterio Lombardo ◽  
Antonio Maraver ◽  
José R. Castón ◽  
José Rivera ◽  
Armando Fernández-Arias ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Disease Virus ◽  
Mammalian Cells ◽  
Infectious Bursal Disease Virus ◽  
Laser Scanning Microscopy ◽  
Infectious Bursal Disease ◽  
Confocal Laser ◽  
Rna Dependent Rna Polymerase ◽  
Virus Like Particles ◽  
Bursal Disease

ABSTRACT A cDNA corresponding to the coding region of VP1, the putative RNA-dependent RNA polymerase, of infectious bursal disease virus (IBDV) was cloned and inserted into the genome of a vaccinia virus inducible expression vector. The molecular mass and antigenic reactivity of VP1 expressed in mammalian cells are identical to those of its counterpart expressed in IBDV-infected cells. The results presented here demonstrate that VP1 is efficiently incorporated into IBDV virus-like particles (VLPs) produced in mammalian cells coexpressing the IBDV polyprotein and VP1. Incorporation of VP1 into VLPs requires neither the presence of IBDV RNAs nor that of the nonstructural polypeptide VP5. Immunofluorescence, confocal laser scanning microscopy, and immunoprecipitation analyses conclusively showed that VP1 forms complexes with the structural polypeptide VP3. Formation of VP1-VP3 complexes is likely to be a key step for the morphogenesis of IBDV particles.

scholarly journals SUMO1 Modification Facilitates Avibirnavirus Replication by Stabilizing Polymerase VP1

2019 ◽  
Vol 93 (10) ◽  
Author(s):  
Huansheng Wu ◽  
Hui Yang ◽  
Gang Ji ◽  
Tuyuan Zheng ◽  
Yina Zhang ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Disease Virus ◽  
Posttranslational Modification ◽  
Infectious Bursal Disease Virus ◽  
Biological Pathways ◽  
Infectious Bursal Disease ◽  
Rna Dependent Rna Polymerase ◽  
Vp1 Protein ◽  
Bursal Disease ◽  
The Stability

ABSTRACT SUMOylation is a posttranslational modification that has crucial roles in diverse cellular biological pathways and in various viral life cycles. In this study, we found that the VP1 protein, the RNA-dependent RNA polymerase of avibirnavirus infectious bursal disease virus (IBDV), regulates virus replication by SUMOylation during infection. Our data demonstrated that the polymerase VP1 is efficiently modified by small ubiquitin-like modifier 1 (SUMO1) in avibirnavirus-infected cell lines. Mutation analysis showed that residues 404I and 406I within SUMO interaction motif 3 of VP1 constitute the critical site for SUMO1 modification. Protein stability assays showed that SUMO1 modification enhanced significantly the stability of polymerase VP1 by inhibiting K48-linked ubiquitination. A reverse genetic approach showed that only IBDV with I404C/T and I406C/F mutations of VP1 could be rescued successfully with decreased replication ability. Our data demonstrated that SUMO1 modification is essential to sustain the stability of polymerase VP1 during IBDV replication and provides a potential target for designing antiviral drugs targeting IBDV. IMPORTANCE SUMOylation is an extensively discussed posttranslational modification in diverse cellular biological pathways. However, there is limited understanding about SUMOylation of viral proteins of IBDV during infection. In the present study, we revealed a SUMO1 modification of VP1 protein, the RNA-dependent RNA polymerase of avibirnavirus infectious bursal disease virus (IBDV). The required site of VP1 SUMOylation comprised residues 404I and 406I of SUMO interaction motif 3, which was essential for maintaining its stability by inhibiting K48-linked ubiquitination. We also showed that IBDV with SUMOylation-deficient VP1 had decreased replication ability. These data demonstrated that the SUMOylation of IBDV VP1 played an important role in maintaining IBDV replication.

scholarly journals Infectious Bursal Disease Virus Capsid Protein VP3 Interacts both with VP1, the RNA-Dependent RNA Polymerase, and with Viral Double-Stranded RNA

2002 ◽  
Vol 76 (22) ◽  
pp. 11301-11311 ◽  
Author(s):  
Mirriam G. J. Tacken ◽  
Ben P. H. Peeters ◽  
Adri A. M. Thomas ◽  
Peter J. M. Rottier ◽  
Hein J. Boot
Keyword(s):  
Rna Polymerase ◽  
Disease Virus ◽  
Infectious Bursal Disease Virus ◽  
Reverse Genetics ◽  
Infectious Bursal Disease ◽  
Rna Dependent Rna Polymerase ◽  
Double Stranded Rna ◽  
Reverse Transcription Pcr ◽  
Bursal Disease ◽  
Carboxy Terminal

ABSTRACT Infectious bursal disease virus (IBDV) is a double-stranded RNA (dsRNA) virus of the Birnaviridae family. Its two genome segments are encapsidated together with multiple copies of the viral RNA-dependent RNA polymerase, VP1, in a single-shell capsid that is composed of VP2 and VP3. In this study we identified the domains responsible for the interaction between VP3 and VP1. Using the yeast two-hybrid system we found that VP1 binds to VP3 through an internal domain, while VP3 interacts with VP1 solely by its carboxy-terminal 10 amino acids. These results were confirmed by using a reverse-genetics system that allowed us to analyze the interaction of carboxy-terminally truncated VP3 molecules with VP1 in infected cells. Coimmunoprecipitations with VP1- and VP3-specific antibodies revealed that the interaction is extremely sensitive to truncation of VP3. The mere deletion of the C-terminal residue reduced coprecipitation almost completely and also fully abolished production of infectious virions. Surprisingly, these experiments additionally revealed that VP3 also binds to RNA. RNase treatments and reverse transcription-PCR analyses of the immunoprecipitates demonstrated that VP3 interacts with dsRNA of both viral genome segments. This interaction is not mediated by the carboxy-terminal domain of VP3 since C-terminal truncations of 1, 5, or 10 residues did not prevent formation of the VP3-dsRNA complexes. VP3 seems to be the key organizer of birnavirus structure, as it maintains critical interactions with all components of the viral particle: itself, VP2, VP1, and the two genomic dsRNAs.

scholarly journals Evidence for functional significance of the permuted C motif in Co2+-stimulated RNA-dependent RNA polymerase of infectious bursal disease virus

2007 ◽  
Vol 88 (10) ◽  
pp. 2824-2833 ◽  
Author(s):  
Tobias Letzel ◽  
Egbert Mundt ◽  
Alexander E. Gorbalenya
Keyword(s):  
Rna Polymerase ◽  
Disease Virus ◽  
Functional Significance ◽  
Infectious Bursal Disease Virus ◽  
Infectious Bursal Disease ◽  
Virus Protein ◽  
Sequence Motifs ◽  
Rdrp Activity ◽  
Rna Dependent Rna Polymerase ◽  
Bursal Disease

Segment B of bisegmented infectious bursal disease virus (IBDV) encodes virus protein 1 (VP1), possessing RNA-dependent RNA polymerase (RdRp) activity. This multidomain protein includes an RdRp domain with a non-canonical order of three sequence motifs forming the active site: C–A–B. The A–B–C order of the motifs, as found in RdRps of the majority of viruses, was converted by relocation (permutation) of motif C to a C–A–B order. Due to the unusual location and unproven significance, the motif was named ‘C?’. This motif includes an Ala–Asp–Asn tripeptide that replaces the C motif Gly–Asp–Asp sequence, widely considered a hallmark of RdRps. In this study, functional significance of the C? motif was investigated by using purified His-tagged VP1 mutants with either a double replacement (ADN to GDD) or two single-site mutants (ADD or GDN). All mutants showed a significant reduction of RdRp activity in vitro, in comparison to that of VP1. Only the least-affected GDN mutant gave rise to viable, albeit partially impaired, progeny using a reverse-genetics system. Experiments performed to investigate whether the C motif was implicated in the control of metal dependence revealed that, compared with Mn2+ and Mg2+, Co2+ stimulated RdRp unconventionally. No activity was observed in the presence of several divalent cations. Of two Co2+ salts with Cl− and anions, the former was a stronger stimulant for RdRp. When cell-culture medium was supplemented with 50 μM Co2+, an increase in IBDV progeny yield was observed. The obtained results provide evidence that the unusual Co2+ dependence of the IBDV RdRp might be linked to the permuted organization of the motif.

scholarly journals Voltage-Dependent Anion Channel 1 Interacts with Ribonucleoprotein Complexes To Enhance Infectious Bursal Disease Virus Polymerase Activity

2017 ◽  
Vol 91 (16) ◽  
Author(s):  
Chunyan Han ◽  
Xiangwei Zeng ◽  
Shuai Yao ◽  
Li Gao ◽  
Lizhou Zhang ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Disease Virus ◽  
Infectious Bursal Disease Virus ◽  
Viral Proteins ◽  
Polymerase Activity ◽  
Infectious Bursal Disease ◽  
Cellular Factor ◽  
Ribonucleoprotein Complexes ◽  
Viral Yield ◽  
Bursal Disease

ABSTRACTInfectious bursal disease virus (IBDV) is a double-stranded RNA (dsRNA) virus. Segment A contains two overlapping open reading frames (ORFs), which encode viral proteins VP2, VP3, VP4, and VP5. Segment B contains one ORF and encodes the viral RNA-dependent RNA polymerase, VP1. IBDV ribonucleoprotein complexes are composed of VP1, VP3, and dsRNA and play a critical role in mediating viral replication and transcription during the virus life cycle. In the present study, we identified a cellular factor, VDAC1, which was upregulated during IBDV infection and found to mediate IBDV polymerase activity. VDAC1 senses IBDV infection by interacting with viral proteins VP1 and VP3. This association is caused by RNA bridging, and all three proteins colocalize in the cytoplasm. Furthermore, small interfering RNA (siRNA)-mediated downregulation ofVDAC1resulted in a reduction in viral polymerase activity and a subsequent decrease in viral yield. Moreover, overexpression of VDAC1 enhanced IBDV polymerase activity. We also found that the viral protein VP3 can replace segment A to execute polymerase activity. A previous study showed that mutations in the C terminus of VP3 directly influence the formation of VP1-VP3 complexes. Our immunoprecipitation experiments demonstrated that protein-protein interactions between VDAC1 and VP3 and between VDAC1 and VP1 play a role in stabilizing the interaction between VP3 and VP1, further promoting IBDV polymerase activity.IMPORTANCEThe cellular factor VDAC1 controls the entry and exit of mitochondrial metabolites and plays a pivotal role during intrinsic apoptosis by mediating the release of many apoptogenic molecules. Here we identify a novel role of VDAC1, showing that VDAC1 interacts with IBDV ribonucleoproteins (RNPs) and facilitates IBDV replication by enhancing IBDV polymerase activity through its ability to stabilize interactions in RNP complexes. To our knowledge, this is the first report that VDAC1 is specifically involved in regulating IBDV RNA polymerase activity, providing novel insight into virus-host interactions.

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