scholarly journals Determination of the henipavirus phosphoprotein gene mRNA editing frequencies and detection of the C, V and W proteins of Nipah virus in virus-infected cells

2009 ◽  
Vol 90 (2) ◽  
pp. 398-404 ◽  
Author(s):  
Michael K. Lo ◽  
Brian H. Harcourt ◽  
Bruce A. Mungall ◽  
Azaibi Tamin ◽  
Mark E. Peeples ◽  
...  
Keyword(s):  
Nipah Virus ◽  
Hendra Virus ◽  
Mrna Editing ◽  
C Protein ◽  
Reading Frame ◽  
Frame Sequence ◽  
P Gene ◽  
Infected Cells ◽  
Phosphoprotein Gene

The henipaviruses, Nipah virus (NiV) and Hendra virus (HeV), are highly pathogenic zoonotic paramyxoviruses. Like many other paramyxoviruses, henipaviruses employ a process of co-transcriptional mRNA editing during transcription of the phosphoprotein (P) gene to generate additional mRNAs encoding the V and W proteins. The C protein is translated from the P mRNA, but in an alternate reading frame. Sequence analysis of multiple, cloned mRNAs showed that the mRNA editing frequencies of the P genes of the henipaviruses are higher than those reported for other paramyxoviruses. Antisera to synthetic peptides from the P, V, W and C proteins of NiV were generated to study their expression in infected cells. All proteins were detected in both infected cells and purified virions. In infected cells, the W protein was detected in the nucleus while P, V and C were found in the cytoplasm.

scholarly journals Nipah Virus Edits Its P Gene at High Frequency To Express the V and W Proteins

2009 ◽  
Vol 83 (8) ◽  
pp. 3982-3987 ◽  
Author(s):  
Sachin Kulkarni ◽  
Valentina Volchkova ◽  
Christopher F. Basler ◽  
Peter Palese ◽  
Viktor E. Volchkov ◽  
...  
Keyword(s):  
High Frequency ◽  
Nipah Virus ◽  
Open Reading Frame ◽  
Mrna Editing ◽  
Reading Frame ◽  
Specific Antibodies ◽  
P Gene ◽  
Gene Transcripts ◽  
Infected Cells ◽  
Over Time

ABSTRACT Nipah virus (NiV) is predicted to encode four proteins from its P gene (P, V, W, and C) via mRNA editing and an alternate open reading frame. By use of specific antibodies, the expression of the V, W, and C proteins in NiV-infected cells has now been confirmed. Analysis of the P-gene transcripts shows a ratio of P:V:W mRNA of 1:1:1, but this differs over time, with greater proportions of V and W transcripts observed as the infection progresses. Eighty-two percent of transcripts are edited, with up to 11 G insertions observed. This exceptionally high editing frequency ensures expression of the V and W proteins.

scholarly journals Mechanisms of Protein Kinase PKR-Mediated Amplification of Beta Interferon Induction by C Protein-Deficient Measles Virus

2009 ◽  
Vol 84 (1) ◽  
pp. 380-386 ◽  
Author(s):  
Christopher S. McAllister ◽  
Ann M. Toth ◽  
Ping Zhang ◽  
Patricia Devaux ◽  
Roberto Cattaneo ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Measles Virus ◽  
Mitogen Activated Protein Kinase ◽  
Potent Inducer ◽  
C Protein ◽  
P Gene ◽  
Mitogen Activated Protein ◽  
Order Of Magnitude ◽  
Infected Cells ◽  
Isogenic Mutants

ABSTRACT The measles virus P gene products V and C antagonize the host interferon (IFN) response, blocking both IFN signaling and production. Using Moraten vaccine strain-derived measles virus and isogenic mutants deficient for either V or C protein production (Vko and Cko, respectively), we observed that the Cko virus was a potent inducer of IFN-β, while induction by Vko virus was an order of magnitude lower than that by the Cko virus. The parental recombinant Moraten virus did not significantly induce IFN-β. The enhanced IFN-inducing capacity of the Cko virus correlated with an enhanced activation of IFN regulatory factor 3 (IRF-3), NF-κB, and ATF-2 in Cko-infected compared to Vko or parental virus-infected cells. Furthermore, protein kinase PKR and mitochondrial adapter IPS-1 were required for maximal Cko-mediated IFN-β induction, which correlated with the PKR-mediated enhancement of mitogen-activated protein kinase and NF-κB activation. Our results reveal multiple consequences of C protein expression and document an important function for PKR as an enhancer of IFN-β induction during measles virus infection.

scholarly journals The C, V and W proteins of Nipah virus inhibit minigenome replication

2008 ◽  
Vol 89 (5) ◽  
pp. 1300-1308 ◽  
Author(s):  
Katrina Sleeman ◽  
Bettina Bankamp ◽  
Kimberly B. Hummel ◽  
Michael K. Lo ◽  
William J. Bellini ◽  
...  
Keyword(s):  
Measles Virus ◽  
Sequence Similarity ◽  
Nipah Virus ◽  
Amino Acid Sequence Similarity ◽  
Dependent Manner ◽  
Highly Pathogenic ◽  
C Protein ◽  
P Gene ◽  
Dose Dependent ◽  
Cat Expression

Nipah virus (NiV) is a recently emergent, highly pathogenic, zoonotic paramyxovirus of the genus Henipavirus. Like the phosphoprotein (P) gene of other paramyxoviruses, the P gene of NiV is predicted to encode three additional proteins, C, V and W. When the C, V and W proteins of NiV were tested for their ability to inhibit expression of the chloramphenicol acetyltransferase (CAT) reporter gene in plasmid-based, minigenome replication assays, each protein inhibited CAT expression in a dose-dependent manner. The C, V and W proteins of NiV also inhibited expression of CAT from a measles virus (MV) minigenome, but not from a human parainfluenzavirus 3 (hPIV3) minigenome. Interestingly, the C and V proteins of MV, which have previously been shown to inhibit MV minigenome replication, also inhibited NiV minigenome replication; however, they were not able to inhibit hPIV3 minigenome replication. In contrast, the C protein of hPIV3 inhibited minigenome replication of hPIV3, NiV and MV. Although there is very limited amino acid sequence similarity between the C, V and W proteins within the paramyxoviruses, the heterotypic inhibition of replication suggests that these proteins may share functional properties.

scholarly journals Two Nucleotides Immediately Upstream of the Essential A6G3 Slippery Sequence Modulate the Pattern of G Insertions during Sendai Virus mRNA Editing

1999 ◽  
Vol 73 (1) ◽  
pp. 343-351 ◽  
Author(s):  
Stéphane Hausmann ◽  
Dominique Garcin ◽  
Anne-Sophie Morel ◽  
Daniel Kolakofsky
Keyword(s):  
Sendai Virus ◽  
Cell System ◽  
Mrna Editing ◽  
Reading Frame ◽  
Recombinant Viruses ◽  
P Gene ◽  
Minimum Number ◽  
Type 3 ◽  
Slippery Sequence ◽  
Bovine Parainfluenza Virus

ABSTRACT Editing of paramyxovirus P gene mRNAs occurs cotranscriptionally and functions to fuse an alternate downstream open reading frame to the N-terminal half of the P protein. G residues are inserted into a short G run contained within a larger purine run (A n G n ) in this process, by a mechanism whereby the transcribing polymerase stutters (i.e., reads the same template cytosine more than once). Although Sendai virus (SeV) and bovine parainfluenza virus type 3 (bPIV3) are closely related, the G insertions in their P mRNAs are distributed differently. SeV predominantly inserts a single G residue within the G run of the sequence 5′ AACAAAAAAGGG, whereas bPIV3 inserts one to six G’s at roughly equal frequency within the sequence 5′ AUUAAAAAAGGGG(differences are underlined). We have examined how thecis-acting editing sequence determines the number of G’s inserted, both in a transfected cell system using minigenome analogues and by generating recombinant viruses. We found that the presence of four rather than three G’s in the purine run did not affect the distribution of G insertions. However, when the underlined AC of the SeV sequence was replaced by the UU found in bPIV3, the editing phenotype from both the minigenome and the recombinant virus resembled that found in natural bPIV3 infections (i.e., a significant fraction of the mRNAs contained two to six G insertions). The two nucleotides located just upstream of the polypurine tract are thus key determinants of the editing phenotype of these viruses. Moreover, the minimum number of A residues that will promote SeV editing phenotype is six but can be reduced to five when the upstream AC is replaced by UU. A model for how the upstream dinucleotide controls the insertion phenotype is presented.

scholarly journals Henipavirus W Proteins Interact with 14-3-3 To Modulate Host Gene Expression

2020 ◽  
Vol 94 (14) ◽  
Author(s):  
Megan R. Edwards ◽  
Mikayla Hoad ◽  
Sofiya Tsimbalyuk ◽  
Andrea R. Menicucci ◽  
Ilhem Messaoudi ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Nipah Virus ◽  
Hendra Virus ◽  
Innate Immune ◽  
Binding Motif ◽  
Mode Iii ◽  
Zoonotic Pathogens ◽  
P Gene ◽  
Host Signaling ◽  
Cocrystal Structure

ABSTRACT Nipah virus (NiV) and Hendra virus (HeV), members of the Henipavirus genus in the Paramyxoviridae family, are recently emerged, highly lethal zoonotic pathogens. The NiV and HeV nonsegmented, negative-sense RNA genomes encode nine proteins, including the W protein. Expressed from the P gene through mRNA editing, W shares a common N-terminus with P and V but has a unique C-terminus. Expressed alone, W modulates innate immune responses by several mechanisms, and elimination of W from NiV alters the course of infection in experimentally infected ferrets. However, the specific host interactions that allow W to modulate innate immunity are incompletely understood. This study demonstrates that the NiV and HeV W proteins interact with all seven isoforms of the 14-3-3 family, regulatory molecules that preferentially bind phosphorylated target proteins to regulate a wide range of cellular functions. The interaction is dependent on the penultimate amino acid residue in the W sequence, a conserved, phosphorylated serine. The cocrystal structure of the W C-terminal binding motif with 14-3-3 provides only the second structure of a complex containing a mode III interactor, which is defined as a 14-3-3 interaction with a phosphoserine/phosphothreonine at the C-termini of the target protein. Transcriptomic analysis of inducible cell lines infected with an RNA virus and expressing either wild-type W or W lacking 14-3-3 binding, identifies new functions for W. These include the regulation of cellular metabolic processes, extracellular matrix organization, and apoptosis. IMPORTANCE Nipah virus (NiV) and Hendra virus (HeV), members of the Henipavirus genus, are recently emerged, highly lethal zoonotic pathogens that cause yearly outbreaks. NiV and HeV each encode a W protein that has roles in regulating host signaling pathways, including antagonism of the innate immune response. However, the mechanisms used by W to regulate these host responses are not clear. Here, characterization of the interaction of NiV and HeV W with 14-3-3 identifies modulation of 14-3-3-regulated host signaling pathways not previously associated with W, suggesting new avenues of research. The cocrystal structure of the NiV W:14-3-3 complex, as only the second structure of a 14-3-3 mode III interactor, provides further insight into this less-well-understood 14-3-3 binding motif.

scholarly journals Nipah Virus C and W Proteins Contribute to Respiratory Disease in Ferrets

2016 ◽  
Vol 90 (14) ◽  
pp. 6326-6343 ◽  
Author(s):  
Benjamin A. Satterfield ◽  
Robert W. Cross ◽  
Karla A. Fenton ◽  
Viktoriya Borisevich ◽  
Krystle N. Agans ◽  
...  
Keyword(s):  
Respiratory Disease ◽  
Neurological Disease ◽  
Synergistic Effects ◽  
Nipah Virus ◽  
Small Animal ◽  
Neurological Impairment ◽  
C Protein ◽  
P Gene ◽  
Virus C ◽  
Viral Determinants

ABSTRACTNipah virus (NiV) is a highly lethal paramyxovirus that recently emerged as a causative agent of febrile encephalitis and severe respiratory disease in humans. The ferret model has emerged as the preferred small-animal model with which to study NiV disease, but much is still unknown about the viral determinants of NiV pathogenesis, including the contribution of the C protein in ferrets. Additionally, studies have yet to examine the synergistic effects of the various P gene products on pathogenesis in animal models. Using recombinant NiVs (rNiVs), we examine the sole contribution of the NiV C protein and the combined contributions of the C and W proteins in the ferret model of NiV pathogenesis. We show that an rNiV void of C expression resulted in 100% mortality, though with limited respiratory disease, like our previously reported rNiV void of W expression; this finding is in stark contrast to the attenuated phenotype observed in previous hamster studies utilizing rNiVs void of C expression. We also observed that an rNiV void of both C and W expression resulted in limited respiratory disease; however, there was severe neurological disease leading to 60% mortality, and the surviving ferrets demonstrated sequelae similar to those for human survivors of NiV encephalitis.IMPORTANCENipah virus (NiV) is a human pathogen capable of causing lethal respiratory and neurological disease. Many human survivors have long-lasting neurological impairment. Using a ferret model, this study demonstrated the roles of the NiV C and W proteins in pathogenesis, where lack of either the C or the W protein independently decreased the severity of clinical respiratory disease but did not decrease lethality. Abolishing both C and W expression, however, dramatically decreased the severity of respiratory disease and the level of destruction of splenic germinal centers. These ferrets still suffered severe neurological disease: 60% succumbed to disease, and the survivors experienced long-term neurological impairment, such as that seen in human survivors. This new ferret NiV C and W knockout model may allow, for the first time, the examination of interventions to prevent or mitigate the neurological damage and sequelae experienced by human survivors.

scholarly journals Nipah Virus Sequesters Inactive STAT1 in the Nucleus via a P Gene-Encoded Mechanism

2009 ◽  
Vol 83 (16) ◽  
pp. 7828-7841 ◽  
Author(s):  
Michael J. Ciancanelli ◽  
Valentina A. Volchkova ◽  
Megan L. Shaw ◽  
Viktor E. Volchkov ◽  
Christopher F. Basler
Keyword(s):  
Tyrosine Phosphorylation ◽  
Nipah Virus ◽  
Mutant Virus ◽  
Wild Type ◽  
Amino Terminal ◽  
Terminal Domain ◽  
P Gene ◽  
Infected Cells ◽  
Amino Terminal Domain ◽  
In Cells

ABSTRACT The Nipah virus (NiV) phosphoprotein (P) gene encodes the C, P, V, and W proteins. P, V, and W, have in common an amino-terminal domain sufficient to bind STAT1, inhibiting its interferon (IFN)-induced tyrosine phosphorylation. P is also essential for RNA-dependent RNA polymerase function. C is encoded by an alternate open reading frame (ORF) within the common amino-terminal domain. Mutations within residues 81 to 113 of P impaired its polymerase cofactor function, as assessed by a minireplicon assay, but these mutants retained STAT1 inhibitory function. Mutations within the residue 114 to 140 region were identified that abrogated interaction with and inhibition of STAT1 by P, V, and W without disrupting P polymerase cofactor function. Recombinant NiVs were then generated. A G121E mutation, which abrogated inhibition of STAT1, was introduced into a C protein knockout background (Cko) because the mutation would otherwise also alter the overlapping C ORF. In cell culture, relative to the wild-type virus, the Cko mutation proved attenuating but the G121E mutant virus replicated identically to the Cko virus. In cells infected with the wild-type and Cko viruses, STAT1 was nuclear despite the absence of tyrosine phosphorylation. This latter observation mirrors what has been seen in cells expressing NiV W. In the G121E mutant virus-infected cells, STAT1 was not phosphorylated and was cytoplasmic in the absence of IFN stimulation but became tyrosine phosphorylated and nuclear following IFN addition. These data demonstrate that the gene for NiV P encodes functions that sequester inactive STAT1 in the nucleus, preventing its activation and suggest that the W protein is the dominant inhibitor of STAT1 in NiV-infected cells.

scholarly journals Complete Genome Sequence of Fer-de-Lance Virus Reveals a Novel Gene in Reptilian Paramyxoviruses

2004 ◽  
Vol 78 (4) ◽  
pp. 2045-2056 ◽  
Author(s):  
Gael Kurath ◽  
William N. Batts ◽  
Winfried Ahne ◽  
James R. Winton
Keyword(s):  
Genome Sequence ◽  
New Genus ◽  
Phylogenetic Analyses ◽  
V Protein ◽  
Reading Frame ◽  
P Gene ◽  
Intergenic Regions ◽  
Infected Cells ◽  
Active Transcription ◽  
Matrix Fusion

ABSTRACT The complete RNA genome sequence of the archetype reptilian paramyxovirus, Fer-de-Lance virus (FDLV), has been determined. The genome is 15,378 nucleotides in length and consists of seven nonoverlapping genes in the order 3′ N-U-P-M-F-HN-L 5′, coding for the nucleocapsid, unknown, phospho-, matrix, fusion, hemagglutinin-neuraminidase, and large polymerase proteins, respectively. The gene junctions contain highly conserved transcription start and stop signal sequences and tri-nucleotide intergenic regions similar to those of other Paramyxoviridae. The FDLV P gene expression strategy is like that of rubulaviruses, which express the accessory V protein from the primary transcript and edit a portion of the mRNA to encode P and I proteins. There is also an overlapping open reading frame potentially encoding a small basic protein in the P gene. The gene designated U (unknown), encodes a deduced protein of 19.4 kDa that has no counterpart in other paramyxoviruses and has no similarity with sequences in the National Center for Biotechnology Information database. Active transcription of the U gene in infected cells was demonstrated by Northern blot analysis, and bicistronic N-U mRNA was also evident. The genomes of two other snake paramyxovirus genotypes were also found to have U genes, with 11 to 16% nucleotide divergence from the FDLV U gene. Pairwise comparisons of amino acid identities and phylogenetic analyses of all deduced FDLV protein sequences with homologous sequences from other Paramyxoviridae indicate that FDLV represents a new genus within the subfamily Paramyxovirinae. We suggest the name Ferlavirus for the new genus, with FDLV as the type species.

scholarly journals Identification of the Rabies Virus Alpha/Beta Interferon Antagonist: Phosphoprotein P Interferes with Phosphorylation of Interferon Regulatory Factor 3

2005 ◽  
Vol 79 (12) ◽  
pp. 7673-7681 ◽  
Author(s):  
Krzysztof Brzózka ◽  
Stefan Finke ◽  
Karl-Klaus Conzelmann
Keyword(s):  
Gene Expression ◽  
Rabies Virus ◽  
Matrix Protein ◽  
Fluorescent Protein ◽  
Regulatory Factor ◽  
Reading Frame ◽  
Beta Interferon ◽  
P Gene ◽  
Infected Cells ◽  
Alpha Beta

ABSTRACT Rabies virus (RV) of the Rhabdoviridae family grows in alpha/beta interferon (IFN)-competent cells, suggesting the existence of viral mechanisms preventing IFN gene expression. We here identify the viral phosphoprotein P as the responsible IFN antagonist. The critical involvement of P was first suggested by the observation that an RV expressing an enhanced green fluorescent protein (eGFP)-P fusion protein (SAD eGFP-P) (S. Finke, K. Brzózka, and K. K. Conzelmann, J. Virol. 78:12333-12343, 2004) was eliminated in IFN-competent HEp-2 cell cultures, in contrast to wild-type (wt) RV or an RV replicon lacking the genes for matrix protein and glycoprotein. SAD eGFP-P induced transcription of the IFN-β gene and expression of the IFN-responsive MxA and STAT-1 genes. Similarly, an RV expressing low levels of P, which was generated by moving the P gene to a promoter-distal gene position (SAD ΔPLP), lost the ability to prevent IFN induction. The analysis of RV mutants lacking expression of truncated P proteins P2, P3, or P4, which are expressed from internal AUG codons of the wt RV P open reading frame, further showed that full-length P is competent in suppressing IFN-β gene expression. In contrast to wt RV, the IFN-inducing SAD ΔPLP caused S386 phosphorylation, dimerization, and transcriptional activity of IFN regulatory factor 3 (IRF-3). Phosphorylation of IRF-3 by TANK-binding kinase-1 expressed from transfected plasmids was abolished in wt RV-infected cells or by cotransfection of P-encoding plasmids. Thus, RV P is necessary and sufficient to prevent a critical IFN response in virus-infected cells by targeting activation of IRF-3 by an upstream kinase.

scholarly journals Remdesivir—Bringing Hope for COVID-19 Treatment

2020 ◽  
Vol 88 (2) ◽  
pp. 29 ◽  
Author(s):  
Naser F. Al-Tannak ◽  
Ladislav Novotny ◽  
Adel Alhunayan
Keyword(s):  
Cyano Group ◽  
Nipah Virus ◽  
World Health ◽  
Analytical Determination ◽  
Nucleotide Analog ◽  
The World ◽  
Pharmacological Data ◽  
Infected Cells ◽  
Health Organization

At the beginning of 2020, the world was swept with a wave of a new coronavirus disease, named COVID-19 by the World Health Organization (WHO 2). The causative agent of this infection is the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The data available on one of the promising therapeutic agents—nucleotide analog remdesivir (Gilead Sciences number GS-5734)—were evaluated. These data were concerned with remdesivir activation from the prodrug to the active molecule—triphosphate containing 1′-cyano group and modified nucleobase. This triphosphate competes with the natural substrate adenosine triphosphate. Additionally, its mechanisms of action based on RNA and proofreading exonuclease inhibition, leading to the delayed RNA chain termination of infected cells, and basic pharmacological data were assessed. Additionally, the analytical determination of remdesivir and its metabolites in cells and body liquids and also some data from remdesivir use in other RNA infections—such as Ebola, Nipah virus infection, and Middle East Respiratory Syndrome (MERS)—were summarized. More recent and more detailed data on the clinical use of remdesivir in COVID-19 were reported, showing the intensive efforts of clinicians and scientists to develop a cure for this new disease. Remdesivir as such represents one of the more promising alternatives for COVID-19 therapy, however the current understanding of this disease and the possible ways of dealing with it requires further investigation.

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