scholarly journals Differential Synergistic Interactions Among Four Different Wheat-Infecting Viruses

2022 ◽  
Vol 12 ◽  
Author(s):  
Satyanarayana Tatineni ◽  
Jeff Alexander ◽  
Feng Qu
Keyword(s):  
Mosaic Virus ◽  
Severe Disease ◽  
Plant Viruses ◽  
Brome Mosaic Virus ◽  
Protein Accumulation ◽  
Drastic Reduction ◽  
Plant Host ◽  
Genomic Rnas ◽  
Synergistic Interactions ◽  
The Impact

Field-grown wheat (Triticum aestivum L.) plants can be co-infected by multiple viruses, including wheat streak mosaic virus (WSMV), Triticum mosaic virus (TriMV), brome mosaic virus (BMV), and barley stripe mosaic virus (BSMV). These viruses belong to four different genera in three different families and are, hence, genetically divergent. However, the impact of potential co-infections with two, three, or all four of them on the viruses themselves, as well as the wheat host, has yet to be examined. This study examined bi-, tri-, and quadripartite interactions among these viruses in wheat for disease development and accumulation of viral genomic RNAs, in comparison with single virus infections. Co-infection of wheat by BMV and BSMV resulted in BMV-like symptoms with a drastic reduction in BSMV genomic RNA copies and coat protein accumulation, suggesting an antagonism-like effect exerted by BMV toward BSMV. However, co-infection of either BMV or BSMV with WSMV or TriMV led to more severe disease than singly infected wheat, but with a decrease or no significant change in titers of interacting viruses in the presence of BMV or BSMV, respectively. These results were in stark contrast with exacerbated disease phenotype accompanied with enhanced virus titers caused by WSMV and TriMV co-infection. Co-infection of wheat by WSMV, TriMV, and BMV or BSMV resulted in enhanced synergistic disease accompanied by increased accumulation of TriMV and BMV but not WSMV or BSMV. Quadripartite interactions in co-infected wheat by all four viruses resulted in very severe disease synergism, leading to the death of the most infected plants, but paradoxically, a drastic reduction in BSMV titer. Our results indicate that interactions among different viruses infecting the same plant host are more complex than previously thought, do not always entail increases in virus titers, and likely involve multiple mechanisms. These findings lay the foundation for additional mechanistic dissections of synergistic interactions among unrelated plant viruses.

scholarly journals Increasing the Capping Efficiency of the Sindbis Virus nsP1 Protein Negatively Affects Viral Infection

2018 ◽  
Author(s):  
Autumn T. LaPointe ◽  
Joaquín Moreno-Contreras ◽  
Kevin J. Sokoloski
Keyword(s):  
Viral Infection ◽  
Growth Kinetics ◽  
Sindbis Virus ◽  
Nonstructural Protein ◽  
Severe Disease ◽  
Protein Accumulation ◽  
Genomic Rnas ◽  
Viral Growth ◽  
Viral Packaging ◽  
The Impact

AbstractAlphaviruses are arthropod-borne RNA viruses that are capable of causing severe disease and are a significant burden to public health. Alphaviral replication results in the production of both capped and noncapped viral genomic RNAs, which are packaged into virions during the infections of vertebrate and invertebrate cells. However, the roles that the noncapped genomic RNAs (ncgRNAs) play during alphaviral infection have yet to be exhaustively characterized. Here, the importance of the ncgRNAs to alphaviral infection was assessed by using mutants of the nsP1 protein of Sindbis virus (SINV), which altered the synthesis of the ncgRNAs during infection by modulating the protein’s capping efficiency. Specifically, point mutants at residues Y286A and N376A decreased capping efficiency, while a point mutant at D355A increased the capping efficiency of the SINV genomic RNA during genuine viral infection. Viral growth kinetics were significantly reduced for the D355A mutant relative to wild type infection, whereas the Y286A and N376A mutants showed modest decreases in growth kinetics. Overall genomic translation and nonstructural protein accumulation was found to correlate with increases and decreases in capping efficiency. However, genomic, minus strand, and subgenomic viral RNA synthesis was largely unaffected by the modulation of alphaviral capping activity. In addition, translation of the subgenomic vRNA was found to be unimpacted by changes in capping efficiency. The mechanism by which decreased presence of ncgRNAs reduced viral growth kinetics was through the impaired production of viral particles. Collectively, these data illustrate the importance of ncgRNAs to viral infection and suggests that they play in integral role in the production of viral progeny.ImportanceAlphaviruses have been the cause of both localized outbreaks and large epidemics of severe disease. Currently, there are no strategies or vaccines which are either safe or effective for preventing alphaviral infection or treating alphaviral disease. This deficit of viable therapeutics highlights the need to better understand the mechanisms behind alphaviral infection in order to develop novel antiviral strategies for alphaviral disease. In particular, this study details a previously uncharacterized aspect of the alphaviral life cycle, the importance of noncapped genomic viral RNAs to alphaviral infection. This offers new insights into the mechanisms of alphaviral replication and the impact of the noncapped genomic RNAs on viral packaging.

scholarly journals tRNA-Like Structure Regulates Translation of Brome Mosaic Virus RNA

2004 ◽  
Vol 78 (8) ◽  
pp. 4003-4010 ◽  
Author(s):  
Sharief Barends ◽  
Joëlle Rudinger-Thirion ◽  
Catherine Florentz ◽  
Richard Giegé ◽  
Cornelis W. A. Pleij ◽  
...  
Keyword(s):  
Coat Protein ◽  
Protein Expression ◽  
Mosaic Virus ◽  
Dominant Role ◽  
Initiation Site ◽  
Plant Viruses ◽  
Brome Mosaic Virus ◽  
Trna Synthetase ◽  
Yellow Mosaic Virus ◽  
Genomic Rnas

ABSTRACT For various groups of plant viruses, the genomic RNAs end with a tRNA-like structure (TLS) instead of the 3′ poly(A) tail of common mRNAs. The actual function of these TLSs has long been enigmatic. Recently, however, it became clear that for turnip yellow mosaic virus, a tymovirus, the valylated TLSTYMV of the single genomic RNA functions as a bait for host ribosomes and directs them to the internal initiation site of translation (with N-terminal valine) of the second open reading frame for the polyprotein. This discovery prompted us to investigate whether the much larger TLSs of a different genus of viruses have a comparable function in translation. Brome mosaic virus (BMV), a bromovirus, has a tripartite RNA genome with a subgenomic RNA4 for coat protein expression. All four RNAs carry a highly conserved and bulky 3′ TLSBMV (about 200 nucleotides) with determinants for tyrosylation. We discovered TLSBMV-catalyzed self-tyrosylation of the tyrosyl-tRNA synthetase but could not clearly detect tyrosine incorporation into any virus-encoded protein. We established that BMV proteins do not need TLSBMV tyrosylation for their initiation. However, disruption of the TLSs strongly reduced the translation of genomic RNA1, RNA2, and less strongly, RNA3, whereas coat protein expression from RNA4 remained unaffected. This aberrant translation could be partially restored by providing the TLSBMV in trans. Intriguingly, a subdomain of the TLSBMV could even almost fully restore translation to the original pattern. We discuss here a model with a central and dominant role for the TLSBMV during the BMV infection cycle.

scholarly journals Increasing the Capping Efficiency of the Sindbis Virus nsP1 Protein Negatively Affects Viral Infection

mBio ◽  
2018 ◽  
Vol 9 (6) ◽  
Author(s):  
Autumn T. LaPointe ◽  
Joaquín Moreno-Contreras ◽  
Kevin J. Sokoloski
Keyword(s):  
Viral Infection ◽  
Growth Kinetics ◽  
Sindbis Virus ◽  
Nonstructural Protein ◽  
Severe Disease ◽  
Point Mutations ◽  
Protein Accumulation ◽  
Genomic Rnas ◽  
Viral Growth ◽  
The Impact

ABSTRACTAlphaviruses are arthropod-borne RNA viruses that are capable of causing severe disease and are a significant burden to public health. Alphaviral replication results in the production of both capped and noncapped viral genomic RNAs (ncgRNAs), which are packaged into virions during infections of vertebrate and invertebrate cells. However, the roles that the ncgRNAs play during alphaviral infection have yet to be exhaustively characterized. Here, the importance of the ncgRNAs to alphaviral infection was assessed by using mutations of the nsP1 protein of Sindbis virus (SINV), which altered the synthesis of the ncgRNAs during infection by modulating the protein’s capping efficiency. Specifically, point mutations at residues Y286A and N376A decreased capping efficiency whereas a point mutation at D355A increased the capping efficiency of the SINV genomic RNA during genuine viral infection. Viral growth kinetics levels were significantly reduced for the D355A mutant relative to wild-type infection, whereas the Y286A and N376A mutants showed modest decreases in growth kinetics. Overall genomic translation and nonstructural protein accumulation were found to correlate with increases and decreases in capping efficiency. However, genomic, minus-strand, and subgenomic viral RNA synthesis were largely unaffected by the modulation of alphaviral capping activity. In addition, translation of the subgenomic alphaviral RNA (vRNA) was found not to be impacted by changes in capping efficiency. The mechanism by which the decreased presence of ncgRNAs reduced viral growth kinetics levels operated through the impaired production of viral particles. Collectively, these data illustrate the importance of ncgRNAs to viral infection and suggest that they play an integral role in the production of viral progeny.IMPORTANCEAlphaviruses have been the cause of both localized outbreaks and large epidemics of severe disease. Currently, there are no strategies or vaccines which are either safe or effective for preventing alphaviral infection or treating alphaviral disease. This deficit of viable therapeutics highlights the need to better understand the mechanisms behind alphaviral infection in order to develop novel antiviral strategies for treatment of alphaviral disease. In particular, this report details a previously uncharacterized aspect of the alphaviral life cycle: the importance of noncapped genomic viral RNAs for alphaviral infection. This offers new insights into the mechanisms of alphaviral replication and the impact of the noncapped genomic RNAs on viral packaging.

scholarly journals Virus-Like Particles Produced Using the Brome Mosaic Virus Recombinant Capsid Protein Expressed in a Bacterial System

2021 ◽  
Vol 22 (6) ◽  
pp. 3098
Author(s):  
Aleksander Strugała ◽  
Jakub Jagielski ◽  
Karol Kamel ◽  
Grzegorz Nowaczyk ◽  
Marcin Radom ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Mosaic Virus ◽  
Capsid Protein ◽  
Self Assembly ◽  
Environmental Changes ◽  
Expression System ◽  
Brome Mosaic Virus ◽  
Virus Like Particles ◽  
Assembly Principles ◽  
The Impact

Virus-like particles (VLPs), due to their nanoscale dimensions, presence of interior cavities, self-organization abilities and responsiveness to environmental changes, are of interest in the field of nanotechnology. Nevertheless, comprehensive knowledge of VLP self-assembly principles is incomplete. VLP formation is governed by two types of interactions: protein–cargo and protein–protein. These interactions can be modulated by the physicochemical properties of the surroundings. Here, we used brome mosaic virus (BMV) capsid protein produced in an E. coli expression system to study the impact of ionic strength, pH and encapsulated cargo on the assembly of VLPs and their features. We showed that empty VLP assembly strongly depends on pH whereas ionic strength of the buffer plays secondary but significant role. Comparison of VLPs containing tRNA and polystyrene sulfonic acid (PSS) revealed that the structured tRNA profoundly increases VLPs stability. We also designed and produced mutated BMV capsid proteins that formed VLPs showing altered diameters and stability compared to VLPs composed of unmodified proteins. We also observed that VLPs containing unstructured polyelectrolyte (PSS) adopt compact but not necessarily more stable structures. Thus, our methodology of VLP production allows for obtaining different VLP variants and their adjustment to the incorporated cargo.

cDNA cloning and in vitro transcription of the complete brome mosaic virus genome

1984 ◽  
Vol 4 (12) ◽  
pp. 2876-2882 ◽  
Author(s):  
P Ahlquist ◽  
M Janda
Keyword(s):  
Mosaic Virus ◽  
Transcription Initiation ◽  
Direct Sequencing ◽  
In Vitro Transcription ◽  
Brome Mosaic Virus ◽  
Viral Rna ◽  
In Vitro Translation ◽  
In Vitro Production ◽  
Genomic Rnas

Complete cDNA copies of each of the brome mosaic virus genomic RNAs (3.2, 2.8, and 2.1 kilobases in length) were cloned in a novel transcription vector, pPM1, designed to provide exact control of the transcription initiation site. After cleavage at a unique EcoRI site immediately downstream of the inserted cDNA, these clones can be transcribed in vitro by Escherichia coli RNA polymerase to yield complete copies of the brome mosaic virus RNAs. Dideoxy sequencing of 5' transcript cDNA runoff products and direct sequencing of 32P-3'-end-labeled transcripts show that such transcripts initiate at the same 5' position as natural viral RNA and terminate within the EcoRI runoff site after copying the entire viral RNA sequence. When synthesized in the presence of m7GpppG, the transcripts bear the natural capped 5' terminus of brome mosaic virus RNAs. Such transcripts direct the in vitro translation of proteins which coelectrophorese with the translation products of natural brome mosaic virus RNAs. pPM1 should facilitate in vitro production of other viral and nonviral RNAs.

scholarly journals Genetic Variation and Possible Mechanisms Driving the Evolution of Worldwide Fig mosaic virus Isolates

2014 ◽  
Vol 104 (1) ◽  
pp. 108-114 ◽  
Author(s):  
Jeewan Jyot Walia ◽  
Anouk Willemsen ◽  
Eminur Elci ◽  
Kadriye Caglayan ◽  
Bryce W. Falk ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Mosaic Virus ◽  
Rna Virus ◽  
Plant Viruses ◽  
Long Distance ◽  
Evolutionary Mechanisms ◽  
Plant Materials ◽  
Genomic Rnas ◽  
Fig Trees ◽  
Fig Mosaic Virus

Fig mosaic virus (FMV) is a multipartite negative-sense RNA virus infecting fig trees worldwide. FMV is transmitted by vegetative propagation and grafting of plant materials, and by the eriophyid mite Aceria ficus. In this work, the genetic variation and evolutionary mechanisms shaping FMV populations were characterized. Nucleotide sequences from four genomic regions (each within the genomic RNAs 1, 2, 3, and 4) from FMV isolates from different countries were determined and analyzed. FMV genetic variation was low, as is seen for many other plant viruses. Phylogenetic analysis showed some geographically distant FMV isolates which clustered together, suggesting long-distance migration. The extent of migration was limited, although varied, between countries, such that FMV populations of different countries were genetically differentiated. Analysis using several recombination algorithms suggests that genomes of some FMV isolates originated by reassortment of genomic RNAs from different genetically similar isolates. Comparison between nonsynonymous and synonymous substitutions showed selection acting on some amino acids; however, most evolved neutrally. This and neutrality tests together with the limited gene flow suggest that genetic drift plays an important role in shaping FMV populations.

scholarly journals Production of Noncapped Genomic RNAs Is Critical to Sindbis Virus Disease and Pathogenicity

mBio ◽  
2020 ◽  
Vol 11 (6) ◽  
Author(s):  
Autumn T. LaPointe ◽  
V Douglas Landers ◽  
Claire E. Westcott ◽  
Kevin J. Sokoloski
Keyword(s):  
Sindbis Virus ◽  
Virus Disease ◽  
Severe Disease ◽  
Wild Type Virus ◽  
Wild Type ◽  
Genomic Rnas ◽  
Mortality And Morbidity ◽  
The Impact

ABSTRACT Alphaviruses are positive-sense RNA viruses that utilize a 5′ cap structure to facilitate translation of viral proteins and to protect the viral RNA genome. Nonetheless, significant quantities of viral genomic RNAs that lack a canonical 5′ cap structure are produced during alphaviral replication and packaged into viral particles. However, the role/impact of the noncapped genomic RNA (ncgRNA) during alphaviral infection in vivo has yet to be characterized. To determine the importance of the ncgRNA in vivo, the previously described D355A and N376A nsP1 mutations, which increase or decrease nsP1 capping activity, respectively, were incorporated into the neurovirulent AR86 strain of Sindbis virus to enable characterization of the impact of altered capping efficiency in a murine model of infection. Mice infected with the N376A nsP1 mutant exhibited slightly decreased rates of mortality and delayed weight loss and neurological symptoms, although levels of inflammation in the brain were similar to those of wild-type infection. Although the D355A mutation resulted in decreased antiviral gene expression and increased resistance to interferon in vitro, mice infected with the D355A mutant showed significantly reduced mortality and morbidity compared to mice infected with wild-type virus. Interestingly, expression of proinflammatory cytokines was found to be significantly decreased in mice infected with the D355A mutant, suggesting that capping efficiency and the production of ncgRNA are vital to eliciting pathogenic levels of inflammation. Collectively, these data indicate that the ncgRNA have important roles during alphaviral infection and suggest a novel mechanism by which noncapped viral RNAs aid in viral pathogenesis. IMPORTANCE Mosquito-transmitted alphaviruses have been the cause of widespread outbreaks of disease that can range from mild illness to lethal encephalitis or severe polyarthritis. There are currently no safe and effective vaccines or therapeutics with which to prevent or treat alphaviral disease, highlighting the need to better understand alphaviral pathogenesis to develop novel antiviral strategies. This report reveals production of noncapped genomic RNAs (ncgRNAs) to be a novel determinant of alphaviral virulence and offers insight into the importance of inflammation to pathogenesis. Taken together, the findings reported here suggest that the ncgRNAs contribute to alphaviral pathogenesis through the sensing of the ncgRNAs during alphaviral infection and are necessary for the development of severe disease.

scholarly journals The Plant Host Can Affect the Encapsidation of Brome Mosaic Virus (BMV) RNA: BMV Virions Are Surprisingly Heterogeneous

2014 ◽  
Vol 426 (5) ◽  
pp. 1061-1076 ◽  
Author(s):  
Peng Ni ◽  
Robert C. Vaughan ◽  
Brady Tragesser ◽  
Haley Hoover ◽  
C. Cheng Kao
Keyword(s):  
Mosaic Virus ◽  
Brome Mosaic Virus ◽  
Plant Host

scholarly journals Conversion in the Requirement of Coat Protein in Cell-to-Cell Movement Mediated by the Cucumber Mosaic Virus Movement Protein

2001 ◽  
Vol 75 (17) ◽  
pp. 8045-8053 ◽  
Author(s):  
Hideaki Nagano ◽  
Kazuyuki Mise ◽  
Iwao Furusawa ◽  
Tetsuro Okuno
Keyword(s):  
Amino Acids ◽  
Coat Protein ◽  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Movement Protein ◽  
Cell Movement ◽  
Plant Viruses ◽  
Brome Mosaic Virus ◽  
Viral Movement ◽  
Intercellular Movement

ABSTRACT Plant viruses have movement protein (MP) gene(s) essential for cell-to-cell movement in hosts. Cucumber mosaic virus (CMV) requires its own coat protein (CP) in addition to the MP for intercellular movement. Our present results using variants of both CMV and a chimeric Brome mosaic virus with the CMV MP gene revealed that CMV MP truncated in its C-terminal 33 amino acids has the ability to mediate viral movement independently of CP. Coexpression of the intact and truncated CMV MPs extremely reduced movement of the chimeric viruses, suggesting that these heterogeneous CMV MPs function antagonistically. Sequential deletion analyses of the CMV MP revealed that the dispensability of CP occurred when the C-terminal deletion ranged between 31 and 36 amino acids and that shorter deletion impaired the ability of the MP to promote viral movement. This is the first report that a region of MP determines the requirement of CP in cell-to-cell movement of a plant virus.

scholarly journals Unravelling the Stability and Capsid Dynamics of the Three Virions of Brome Mosaic Virus Assembled Autonomously In Vivo

2019 ◽  
Author(s):  
Antara Chakravarty ◽  
Christian Beren ◽  
Rees Garmann ◽  
A.L.N. Rao
Keyword(s):  
Mosaic Virus ◽  
Transient Expression ◽  
Rna Binding ◽  
Conformational Dynamics ◽  
Brome Mosaic Virus ◽  
Crystallographic Structure ◽  
Binding Motif ◽  
Genomic Rnas ◽  
Viral Capsids

ABSTRACTViral capsids are dynamic assemblies that undergo controlled conformational transitions to perform various biological functions. The replicated three-molecule RNA progeny of Brome mosaic virus (BMV) are packaged by a single capsid protein (CP) into three types of morphologically indistinguishable icosahedral virions with T=3 quasi-symmetry. Type 1 (B1v) and type 2 (B2v) virions respectively package genomic RNA1 or RNA2, while type 3 (B3+4v) co-packages genomic RNA3 (B3) and its sub-genomic RNA4 (B4). In this study, the application of a robust Agrobacterium-mediated transient expression system allowed us to assemble each virion type separately in planta. Physical and biochemical approaches analyzing the morphology, size, and electrophoretic mobility failed to distinguish between the virion types, so protease-based mapping experiments were used to analyze the conformational dynamics of the individual virions. The crystallographic structure of the BMV capsid shows four trypsin-cleavage sites (K65, R103, K111 and K165 on the A, B and C subunits) exposed on the exterior of the capsid. Irrespective of the digestion time, while retaining their capsid structural integrity, B1v and B2v released only two peptides involving amino acids 2-8 and 16-22 from the N-proximal arginine-rich RNA binding motif. In contrast, B3+4v capsids are unstable to trypsin, releasing several peptides in addition to the four sites predicted to be exposed on the capsid exterior. These results, demonstrating qualitatively different dynamics for the three types of BMV virions, suggest that the different RNA genes they contain may have different translational timing and efficiency and may even impart different structures to their capsids.IMPORTANCEThe majority of viruses contain RNA genomes protected by a shell of capsid proteins. Although crystallographic studies show that viral capsids are static structures, accumulating evidence suggests that in solution virions are highly dynamic assemblies. The three genomic RNAs (RNAs 1, 2 and 3) and a single subgenomic RNA (RNA4) of Brome mosaic virus (BMV), an RNA virus pathogenic to plants, are distributed among three physically homogeneous virions. This study examines the capsid dynamics by MALDI-TOF analyses following trypsin digestion of the three virions assembled separately in vivo using the Agrobacterium-mediated transient expression approach. The results provide compelling evidence that virions packaging genomic RNAs1 and 2 are more stable and dynamically distinct from those co-packaging RNA3 and 4, suggesting that RNA-dependent capsid dynamics play an important biological role in the viral life cycle.

Sign in / Sign up

Export Citation Format

Share Document