scholarly journals Role of the Hypervariable Hinge Region of Phosphoprotein P of Vesicular Stomatitis Virus in Viral RNA Synthesis and Assembly of Infectious Virus Particles

2005 ◽  
Vol 79 (13) ◽  
pp. 8101-8112 ◽  
Author(s):  
Subash C. Das ◽  
Asit K. Pattnaik

ABSTRACT The phosphoprotein (P protein) of vesicular stomatitis virus (VSV) is an essential subunit of the viral RNA-dependent RNA polymerase and has multiple functions residing in its different domains. In the present study, we examined the role of the hypervariable hinge region of P protein in viral RNA synthesis and recovery of infectious VSV by using transposon-mediated insertion mutagenesis and deletion mutagenesis. We observed that insertions of 19-amino-acid linker sequences at various positions within this region affected replication and transcription functions of the P protein to various degrees. Interestingly, one insertion mutant was completely defective in both transcription and replication. Using a series of deletion mutants spanning the hinge region of the protein, we observed that amino acid residues 201 through 220 are required for the activity of P protein in both replication and transcription. Neither insertion nor deletion had any effect on the interaction of P protein with N or L proteins. Infectious VSVs with a deletion in the hinge region possessed retarded growth characteristics and exhibited small-plaque morphology. Interestingly, VSV containing one P protein deletion mutant (PΔ7, with amino acids 141 through 200 deleted), which possessed significant levels of replication and transcription activity, could be amplified only by passage in cells expressing the wild-type P protein. We conclude that the hypervariable hinge region of the P protein plays an important role in viral RNA synthesis. Furthermore, our results provide a previously unidentified function for the P protein: it plays a critical role in the assembly of infectious VSV.

2013 ◽  
Vol 88 (3) ◽  
pp. 1461-1472 ◽  
Author(s):  
A. Mondal ◽  
K. G. Victor ◽  
R. S. Pudupakam ◽  
C. E. Lyons ◽  
G. W. Wertz

2006 ◽  
Vol 80 (13) ◽  
pp. 6368-6377 ◽  
Author(s):  
Subash C. Das ◽  
Debasis Nayak ◽  
You Zhou ◽  
Asit K. Pattnaik

ABSTRACT The phosphoprotein (P) of vesicular stomatitis virus (VSV) is a subunit of the viral RNA polymerase. In previous studies, we demonstrated that insertion of 19 amino acids in the hinge region of the protein had no significant effect on P protein function. In the present study, we inserted full-length enhanced green fluorescent protein (eGFP) in frame into the hinge region of P and show that the fusion protein (PeGFP) is functional in viral genome transcription and replication, albeit with reduced activity. A recombinant vesicular stomatitis virus encoding PeGFP in place of the P protein (VSV-PeGFP), which possessed reduced growth kinetics compared to the wild-type VSV, was recovered. Using the recombinant VSV-PeGFP, we show that the viral replication proteins and the de novo-synthesized RNA colocalize to sites throughout the cytoplasm, indicating that replication and transcription are not confined to any particular region of the cytoplasm. Real-time imaging of the cells infected with the eGFP-tagged virus revealed that, following synthesis, the nucleocapsids are transported toward the cell periphery via a microtubule (MT)-mediated process, and the nucleocapsids were seen to be closely associated with mitochondria. Treatment of cells with nocodazole or Colcemid, drugs known to inhibit MT polymerization, resulted in accumulation of the nucleocapsids around the nucleus and also led to inhibition of infectious-virus production. These findings are compatible with a model in which the progeny viral nucleocapsids are transported toward the cell periphery by MT and the transport may be facilitated by mitochondria.


2008 ◽  
Vol 83 (4) ◽  
pp. 1930-1940 ◽  
Author(s):  
Jianrong Li ◽  
Amal Rahmeh ◽  
Vesna Brusic ◽  
Sean P. J. Whelan

ABSTRACT The multifunctional large (L) polymerase protein of vesicular stomatitis virus (VSV) contains enzymatic activities essential for RNA synthesis, including mRNA cap addition and polyadenylation. We previously mapped amino acid residues G1154, T1157, H1227, and R1228, present within conserved region V (CRV) of L, as essential for mRNA cap addition. Here we show that alanine substitutions to these residues also affect 3′-end formation. Specifically, the cap-defective polymerases produced truncated transcripts that contained A-rich sequences at their 3′ termini and predominantly terminated within the first 500 nucleotides (nt) of the N gene. To examine how the cap-defective polymerases respond to an authentic VSV termination and reinitiation signal present at each gene junction, we reconstituted RNA synthesis using templates that contained genes inserted (I) at the leader-N gene junction. The I genes ranged in size from 382 to 1,098 nt and were typically transcribed into full-length uncapped transcripts. In addition to lacking a cap structure, the full-length I transcripts synthesized by the cap-defective polymerases lacked an authentic polyadenylate tail and instead contained 0 to 24 A residues. Moreover, the cap-defective polymerases were also unable to copy efficiently the downstream gene. Thus, single amino acid substitutions in CRV of L protein that inhibit cap addition also inhibit polyadenylation and sequential transcription of the genome. In contrast, an amino acid substitution, K1651A, in CRVI of L protein that completely inhibits cap methylation results in the hyperpolyadenylation of mRNA. This work reveals that inhibiting cap addition and cap methylation have opposing effects on polyadenylation during VSV mRNA synthesis and provides evidence in support of a link between correct 5′ cap formation and 3′ polyadenylation.


2015 ◽  
Vol 89 (21) ◽  
pp. 11002-11010 ◽  
Author(s):  
Adrian Pickar ◽  
Andrew Elson ◽  
Yang Yang ◽  
Pei Xu ◽  
Ming Luo ◽  
...  

ABSTRACTThe mumps virus (MuV) genome encodes a phosphoprotein (P) that is important for viral RNA synthesis. P forms the viral RNA-dependent RNA polymerase with the large protein (L). P also interacts with the viral nucleoprotein (NP) and self-associates to form a homotetramer. The P protein consists of three domains, the N-terminal domain (PN), the oligomerization domain (PO), and the C-terminal domain (PC). While PNis known to relax the NP-bound RNA genome, the roles of POand PCare not clear. In this study, we investigated the roles of POand PCin viral RNA synthesis using mutational analysis and a minigenome system. We found that PNand PCfunctions can betrans-complemented. However, this complementation requires PO, indicating that POis essential for P function. Using thistrans-complementation system, we found that P forms parallel dimers (PNto PNand PCto PC). Furthermore, we found that residues R231, K238, K253, and K260 in POare critical for P's functions. We identified PCto be the domain that interacts with L. These results provide structure-function insights into the role of MuV P.IMPORTANCEMuV, a paramyxovirus, is an important human pathogen. The P protein of MuV is critical for viral RNA synthesis. In this work, we established a novel minigenome system that allows the domains of P to be complemented intrans. Using this system, we confirmed that MuV P forms parallel dimers. An understanding of viral RNA synthesis will allow the design of better vaccines and the development of antivirals.


2007 ◽  
Vol 82 (2) ◽  
pp. 674-682 ◽  
Author(s):  
Xin Zhang ◽  
Todd J. Green ◽  
Jun Tsao ◽  
Shihong Qiu ◽  
Ming Luo

ABSTRACT The crystal structure of the vesicular stomatitis virus nucleoprotein (N) in complex with RNA reveals extensive and specific intermolecular interactions among the N molecules in the 10-member oligomer. What roles these interactions play in encapsidating RNA was studied by mutagenesis of the N protein. Three N mutants intended for disruption of the intermolecular interactions were designed and coexpressed with the phosphoprotein (P) in an Escherichia coli system previously described (T. J. Green et al., J. Virol. 74:9515-9524, 2000). Mutants N (Δ1-22), N (Δ347-352), and N (320-324, (Ala)5) lost RNA encapsidation and oligomerization but still bound with P. Another mutant, N (Ser290→Trp), was able to form a stable ring-like N oligomer and bind with the P protein but was no longer able to encapsidate RNA. The crystal structure of N (Ser290→Trp) at 2.8 Å resolution showed that this mutant can maintain all the same intermolecular interactions as the wild-type N except for a slight unwinding of the N-terminal lobe. These results suggest that the intermolecular contacts among the N molecules are required for encapsidation of the viral RNA.


Cell ◽  
1985 ◽  
Vol 41 (1) ◽  
pp. 259-267 ◽  
Author(s):  
Heinz Arnheiter ◽  
Nancy L. Davis ◽  
Gail Wertz ◽  
Manfred Schubert ◽  
Robert A. Lazzarini

2006 ◽  
Vol 80 (19) ◽  
pp. 9511-9518 ◽  
Author(s):  
Mingzhou Chen ◽  
Tomoaki Ogino ◽  
Amiya K. Banerjee

ABSTRACT The phosphoprotein (P protein) of vesicular stomatitis virus (VSV) is an essential subunit of the viral RNA-dependent RNA polymerase complex and plays a central role in viral transcription and replication. Using both the yeast two-hybrid system and coimmunoprecipitation assays, we confirmed the self-association of the P protein of Indiana serotype (Pind) and heterotypic interaction between Pind and the P protein of New Jersey serotype (Pnj). Furthermore, by using various truncation and deletion mutants of Pind, the self-association domain of the Pind protein was mapped to amino acids 161 to 210 within the hinge region. The self-association domain of Pind protein is not required for its binding to nucleocapsid and large proteins. We further demonstrated that the self-association domain of Pind protein is essential for VSV transcription in a minireplicon system and that a synthetic peptide spanning amino acids 191 to 210 in the self-association domain of Pind protein strongly inhibited the transcription of the VSV genome in vitro in a dose-dependent manner. These results indicated that the self-association domain of Pind protein plays a critical role in VSV transcription.


1988 ◽  
Vol 11 ◽  
pp. 29
Author(s):  
William B. Helfman ◽  
J.David Beckes ◽  
Lisa C. Childers ◽  
Jacques Perrault

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