Defective Interfering RNAs of a Satellite Virus

ABSTRACT Panicum mosaic virus (PMV) is a recently molecularly characterized RNA virus with the unique feature of supporting the replication of two subviral RNAs in a few species of the familyGramineae. The subviral agents include a satellite RNA (satRNA) that is devoid of a coding region and the unrelated satellite panicum mosaic virus (SPMV) that encodes its own capsid protein. Here we report the association of this complex with a new entity in the RNA world, a defective-interfering RNA (DI) of a satellite virus. The specificity of interactions governing this four-component viral system is illustrated by the ability of the SPMV DIs to strongly interfere with the accumulation of the parental SPMV. The SPMV DIs do not interfere with PMV satRNA, but they do slightly enhance the rate of spread and titer of PMV. The SPMV-derived DIs provide an additional avenue by which to investigate fundamental biological questions, including the evolution and interactions of infectious RNAs.

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Isolation and Characterization of an Arterivirus Defective Interfering RNA Genome

Journal of Virology ◽

10.1128/jvi.74.7.3156-3165.2000 ◽

2000 ◽

Vol 74 (7) ◽

pp. 3156-3165 ◽

Cited By ~ 27

Author(s):

Richard Molenkamp ◽

Babette C. D. Rozier ◽

Sophie Greve ◽

Willy J. M. Spaan ◽

Eric J. Snijder

Keyword(s):

Rna Virus ◽

Equine Arteritis Virus ◽

Reading Frame ◽

Isolation And Characterization ◽

The Family ◽

Defective Interfering Rna ◽

Rna Genome ◽

Interfering Rna ◽

Discontinuous Transcription

ABSTRACT Equine arteritis virus (EAV), the type member of the family Arteriviridae, is a single-stranded RNA virus with a positive-stranded genome of approximately 13 kb. EAV uses a discontinuous transcription mechanism to produce a nested set of six subgenomic mRNAs from which its structural genes are expressed. We have generated the first documented arterivirus defective interfering (DI) RNAs by serial undiluted passaging of a wild-type EAV stock in BHK-21 cells. A cDNA copy of the smallest DI RNA (5.6 kb) was cloned. Upon transfection into EAV-infected BHK-21 cells, transcripts derived from this clone (pEDI) were replicated and packaged. Sequencing of pEDI revealed that the DI RNA was composed of three segments of the EAV genome (nucleotides 1 to 1057, 1388 to 1684, and 8530 to 12704) which were fused in frame with respect to the replicase reading frame. Remarkably, this DI RNA has retained all of the sequences encoding the structural proteins. By insertion of the chloramphenicol acetyltransferase reporter gene in the DI RNA genome, we were able to delimitate the sequences required for replication/DI-based transcription and packaging of EAV DI RNAs and to reduce the maximal size of a replication-competent EAV DI RNA to approximately 3 kb.

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First Report of a Mesonivirus and Its Derived Small RNAs in an Aphid Species Aphis citricidus (Hemiptera: Aphididae), Implying Viral Infection Activity

Journal of Insect Science ◽

10.1093/jisesa/ieaa022 ◽

2020 ◽

Vol 20 (2) ◽

Author(s):

Tengyu Chang ◽

Mengmeng Guo ◽

Wei Zhang ◽

Jinzhi Niu ◽

Jin-Jun Wang

Keyword(s):

Viral Infection ◽

Small Rnas ◽

Rna Virus ◽

Aphid Species ◽

Open Reading Frames ◽

First Report ◽

The Family ◽

Interfering Rna ◽

Unassigned Genus ◽

Reading Frames

Abstract We report a new positive-sense single-stranded RNA (ss RNA+) virus from the brown citrus aphid Aphis citricidus. The 20,300 nucleotide (nt)-long viral genome contains five open-reading frames and encodes six conserved domains (TM2, 3CLpro, TM3, RdRp, Zm, and HEL1). Phylogenetic analysis and amino acid sequence analysis revealed this virus might belong to an unassigned genus in the family Mesoniviridae. The presence of the virus was also confirmed in the field population. Importantly, analysis of the virus-derived small RNAs showed a 22-nt peak, implying that viral infection triggers the small interfering RNA pathway as antiviral immunity in aphids. This is the first report of a mesonivirus in invertebrates other than mosquitoes.

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3′-End Stem-Loops of the Subviral RNAs Associated with Turnip Crinkle Virus Are Involved in Symptom Modulation and Coat Protein Binding

Journal of Virology ◽

10.1128/jvi.74.14.6528-6537.2000 ◽

2000 ◽

Vol 74 (14) ◽

pp. 6528-6537 ◽

Cited By ~ 13

Author(s):

Jianlong Wang ◽

Anne E. Simon

Keyword(s):

Coat Protein ◽

Turnip Crinkle Virus ◽

Complementary Strand ◽

Satellite Rna ◽

Stem Loop ◽

Subviral Rnas ◽

Translation Initiation Codon ◽

Defective Interfering Rna ◽

Symptom Modulation ◽

Interfering Rna

ABSTRACT Many plant RNA viruses are associated with one or more subviral RNAs. Two subviral RNAs, satellite RNA C (satC) and defective interfering RNA G (diG) intensify the symptoms of their helper, turnip crinkle virus (TCV). However, when the coat protein (CP) of TCV was replaced with that of the related Cardamine chlorotic fleck virus (CCFV), both subviral RNAs attenuated symptoms of the hybrid virus TCV-CPCCFV. In contrast, when the translation initiation codon of the TCV CP was altered to ACG and reduced levels of CP were synthesized, satC attenuated symptoms while diG neither intensified nor attenuated symptoms. The determinants for this differential symptom modulation were previously localized to the 3′-terminal 100 bases of the subviral RNAs, which contain six positional differences (Q. Kong, J.-W. Oh, C. D. Carpenter, and A. E. Simon, Virology 238:478–485, 1997). In the current study, we have determined that certain sequences within the 3′-terminal stem-loop structures of satC and diG, which also serve as promoters for complementary strand synthesis, are critical for symptom modulation. Furthermore, the ability to attenuate symptoms was correlated with weakened binding of TCV CP to the hairpin structure.

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Enterovirus D-68 Molecular Virology, Epidemiology, and Treatment: an update and way forward

Infectious Disorders - Drug Targets ◽

10.2174/1871526520666200715101230 ◽

2020 ◽

Vol 20 ◽

Author(s):

Mahmoud Ahmed Ebada ◽

Notila Fayed ◽

Souad Alkanj ◽

Ahmed Wadaa Allah

Keyword(s):

Current Knowledge ◽

Rna Virus ◽

Neurological Diseases ◽

Cross Reactivity ◽

Serological Tests ◽

Molecular Virology ◽

Acute Flaccid Myelitis ◽

The Family ◽

Pcr Products ◽

Enterovirus D68

: Enterovirus D68 (EV-D68) is a single-stranded positive-sense RNA virus, and it is one of the family Picornaviridae. Except for EV-D68, the family Picornaviridae has been illustrated in literature. EV-D68 was first discovered and isolated in California, USA, in 1962. EV-D68 has resulted in respiratory disorders’ outbreaks among children worldwide, and it has been detected in cases of various neurological diseases such as acute flaccid myelitis (AFM). A recent study documented a higher number of EV-D68 cases associated with AFM in Europe in 2016 compared to the 2014 outbreak. EV-D68 is mainly diagnosed by quantitative PCR, and there is an affirmative strategy for EV-D68 detection by using pan-EV PCR on the untranslated region and/or the VP1 or VP2, followed by sequencing of the PCR products. Serological tests are limited due to cross-reactivity of the antigens between the different serotypes. Many antiviral drugs for EV-D68 have been evaluated, and showed promising results. In our review, we discuss the current knowledge about EV-D68 and its role in the development of AFM.

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Role of Soybean mosaic virus–Encoded Proteins in Seed and Aphid Transmission in Soybean

Phytopathology ◽

10.1094/phyto-09-12-0248-r ◽

2013 ◽

Vol 103 (9) ◽

pp. 941-948 ◽

Cited By ~ 21

Author(s):

Sushma Jossey ◽

Houston A. Hobbs ◽

Leslie L. Domier

Keyword(s):

Mosaic Virus ◽

Seed Quality ◽

Soybean Mosaic Virus ◽

Seed Transmission ◽

Aphid Transmission ◽

Plant Introduction ◽

Sequence Motif ◽

Coding Region ◽

Encoded Proteins ◽

Seed Transmissibility

Soybean mosaic virus (SMV) is seed and aphid transmitted and can cause significant reductions in yield and seed quality in soybean (Glycine max). The roles in seed and aphid transmission of selected SMV-encoded proteins were investigated by constructing mutants in and chimeric recombinants between SMV 413 (efficiently aphid and seed transmitted) and an isolate of SMV G2 (not aphid or seed transmitted). As previously reported, the DAG amino acid sequence motif near the amino terminus of the coat protein (CP) was the major determinant in differences in aphid transmissibility of the two SMV isolates, and helper component proteinase (HC-Pro) played a secondary role. Seed transmission of SMV was influenced by P1, HC-Pro, and CP. Replacement of the P1 coding region of SMV 413 with that of SMV G2 significantly enhanced seed transmissibility of SMV 413. Substitution in SMV 413 of the two amino acids that varied in the CPs of the two isolates with those from SMV G2, G to D in the DAG motif and Q to P near the carboxyl terminus, significantly reduced seed transmission. The Q-to-P substitution in SMV 413 also abolished virus-induced seed-coat mottling in plant introduction 68671. This is the first report associating P1, CP, and the DAG motif with seed transmission of a potyvirus and suggests that HC-Pro interactions with CP are important for multiple functions in the virus infection cycle.

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A novel, multipartite, negative-strand RNA virus is associated with the ringspot disease of European mountain ash (Sorbus aucuparia L.)

Journal of General Virology ◽

10.1099/vir.0.82715-0 ◽

2007 ◽

Vol 88 (4) ◽

pp. 1337-1346 ◽

Cited By ~ 57

Author(s):

Nicole Mielke ◽

Hans-Peter Muehlbach

Keyword(s):

Rna Virus ◽

Plant Viruses ◽

Glycoprotein Precursor ◽

Structure Comparison ◽

Viral Rnas ◽

Pathogenic Virus ◽

Mountain Ash ◽

The Family ◽

European Mountain ◽

Novel Virus

Four RNAs from a new plant-pathogenic virus, which we have tentatively named European mountain ash ringspot-associated virus (EMARAV), were identified and sequenced completely. All four viral RNAs could be detected in previous double-stranded RNA preparations. RNA 1 (7040 nt) encodes a protein with similarity to the RNA-dependent RNA polymerase of different members of the Bunyaviridae, a family containing five genera with viruses infecting invertebrates, vertebrates and plants. RNA 2 (2335 nt) encodes a 75 kDa protein containing a conserved motif of the glycoprotein precursor of the genus Phlebovirus. Immunological detection indicated the presence of proteins with the expected size of the precursor and one of its processing products. The amino acid sequence of protein p3 (35 kDa) encoded by RNA 3 shows similarities to a putative nucleocapsid protein of two still unclassified plant viruses. The fourth viral RNA encodes a 27 kDa protein that has no significant homology to any known protein. As is typical for members of the family Bunyaviridae, the 5′ and 3′ ends of all viral RNAs are complementary, which allows the RNA to form a panhandle structure. Comparison of these sequences demonstrates a conserved terminal part of 13 nt, similar to that of the bunyaviral genus Orthobunyavirus. Despite the high agreement of the EMARAV genome with several characteristics of the family Bunyaviridae, there are a few features that make it difficult to allocate the virus to this group. It is therefore more likely that this plant pathogen belongs to a novel virus genus.

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RNA Silencing Suppression by a Second Copy of the P1 Serine Protease of Cucumber Vein Yellowing Ipomovirus, a Member of the Family Potyviridae That Lacks the Cysteine Protease HCPro

Journal of Virology ◽

10.1128/jvi.00985-06 ◽

2006 ◽

Vol 80 (20) ◽

pp. 10055-10063 ◽

Cited By ~ 80

Author(s):

Adrian Valli ◽

Ana Montserrat Martín-Hernández ◽

Juan José López-Moya ◽

Juan Antonio García

Keyword(s):

Rna Silencing ◽

Fluorescent Protein ◽

Serine Proteinase ◽

Plum Pox Virus ◽

Coding Region ◽

Long Distance ◽

Systemic Spread ◽

The Family ◽

Silencing Suppression ◽

Green Fluorescent

ABSTRACT The P1 protein of viruses of the family Potyviridae is a serine proteinase, which is highly variable in length and sequence, and its role in the virus infection cycle is not clear. One of the proposed activities of P1 is to assist HCPro, the product that viruses of the genus Potyvirus use to counteract antiviral defense mediated by RNA silencing. Indeed, an HCPro-coding region is present in all the genomes of members of the genera Potyvirus, Rymovirus, and Tritimovirus that have been sequenced. However, it was recently reported that a sequence coding for HCPro is lacking in the genome of Cucumber vein yellowing virus (CVYV), a member of the genus Ipomovirus, the fourth monopartite genus of the family. In this study, we provide further evidence that P1 enhances the activity of HCPro in members of the genus Potyvirus and show that it is duplicated in the ipomovirus CVYV. The two CVYV P1 copies are arranged in tandem, and the second copy (P1b) has RNA silencing suppression activity. CVYV P1b suppressed RNA silencing induced either by sense green fluorescent protein (GFP) mRNA or by a GFP inverted repeat RNA, indicating that CVYV P1b acts downstream of the formation of double-stranded RNA. CVYV P1b also suppressed local silencing in agroinfiltrated patches of transgenic Nicotiana benthamiana line 16c and delayed its propagation to the neighboring cells. However, neither the short-distance nor long-distance systemic spread of silencing of the GFP transgene was completely blocked by CVYV P1b. CVYV P1b and P1-HCPro from the potyvirus Plum pox virus showed very similar behaviors in all the assays carried out, suggesting that evolution has found a way to counteract RNA silencing by similar mechanisms using very different proteins in viruses of the same family.

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Advancing RNA Virus Discovery and Biology with Whole Genome Sequencing

10.21007/etd.cghs.2021.0551 ◽

2021 ◽

Author(s):

◽

Mariah Taylor ◽

Keyword(s):

Genetic Variation ◽

Amino Acid ◽

Whole Genome Sequencing ◽

Genome Sequencing ◽

Rna Virus ◽

Animal Health ◽

Functional Domains ◽

Whole Genome ◽

Coding Region

Two RNA virus families that pose a threat to human and animal health are Hantaviridae and Coronaviridae. These RNA viruses which originate in wildlife continue and will continue to cause disease, and hence, it is critical that scientific research define the mechanisms as to how these viruses spillover and adapt to new hosts to become endemic. One gap in our ability to define these mechanisms is the lack of whole genome sequences for many of these viruses. To address this specific gap, I developed a versatile amplicon-based whole-genome sequencing (WGS) approach to identify viral genomes of hantaviruses and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within reservoir and spillover hosts. In my research studies, I used the amplicon-based WGS approach to define the genetic plasticity of viral RNA within pathogenic and nonpathogenic hantavirus species. The standing genetic variation of Andes orthohantavirus and Prospect Hill orthohantavirus was mapped out and amino acid changes occurring outside of functional domains were identified within the nucleocapsid and glycoprotein. I observed several amino acid changes in functional domains of the RNA-dependent RNA polymerase, as well as single nucleotide polymorphisms (SNPs) within the 3’ non-coding region (NCR) of the S-segment. To identify whether virus adaptation would occur within the S- and L-segments we attempted to adapt hantaviruses in vitro in a spillover host model through passaging experiments. In early passages we identified few mutations in the M-segment with the majority being identified in the S-segment 3’ NCR and the L-segment. This work suggests that hantavirus adaptation occurs in the S- and L-segments although the effect of these mutants on pathology is yet to be determined. While sequencing laboratory isolates is easily accomplished, sequencing low concentrations of virus within the reservoir is a formidable task. I further translated our amplicon-based WGS approach into a pan-oligonucleotide amplicon-based WGS approach to sequence hantavirus vRNA and mRNA from reservoir and spillover hosts in Ukraine. This approach successfully identified a novel Puumala orthohantavirus (PUUV) strain in Ukraine and using Bayesian phylogenetics we found this strain to be associated with the PUUV Latvian lineage. Early during the SARS-CoV-2 pandemic, I applied the knowledge gained in the hantavirus WGS efforts to sequencing of SARS-CoV-2 from nasopharyngeal swabs collected in April 2020. The genetic diversity of 45 SARS-CoV-2 isolates was evaluated with the methods I developed. We identified D614G, a notable mutation known for increasing transmission, in over 90% of our isolates. Two major lineages distinguish SARS-CoV-2 variants worldwide, lineages A and B. While most of our isolates were found within B lineage, we also identified one isolate within lineage A. We performed in vitro work which confirmed A lineage isolates as having poor replication in the trachea as compared to the nasal cavity. Five of these isolates presented a unique array of mutations which were assessed in the keratin 18 human angiotensin-converting enzyme 2 (K18-hACE2) mouse model for its response immunologically and pathogenically. We identified a distinction of pathogenesis between the A and B lineages with emphysema being common amongst A lineage isolates. Additionally, we discovered a small cohort of likely SNPs that defined the late induction of eosinophils during infection. In summary, this work will further define the dynamics of genetic variation and plasticity within virus populations that cause disease outbreaks and will allow a deeper understanding of the virus-host relationship.

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Molecular characterization of a novel mycovirus isolated from Rhizoctonia solani AG-1 IA 9-11

10.21203/rs.3.rs-520549/v1 ◽

2021 ◽

Author(s):

Yang Sun ◽

Yan qiong Li ◽

Wen han Dong ◽

Ai li Sun ◽

Ning wei Chen ◽

...

Keyword(s):

Rhizoctonia Solani ◽

Rna Virus ◽

Dsrna Virus ◽

Open Reading Frames ◽

The Family ◽

Significant Amino Acid Sequence ◽

Overlapping Open Reading Frames ◽

Significant Amino Acid ◽

Reading Frames

Abstract The complete genome of the dsRNA virus isolated from Rhizoctonia solani AG-1 IA 9–11 (designated as Rhizoctonia solani dsRNA virus 11, RsRV11 ) were determined. The RsRV11 genome was 9,555 bp in length, contained three conserved domains, SMC, PRK and RT-like super family, and encoded two non-overlapping open reading frames (ORFs). ORF1 potentially coded for a 204.12 kDa predicted protein, which shared low but significant amino acid sequence identities with the putative protein encoded by Rhizoctonia solani RNA virus HN008 (RsRV-HN008) ORF1. ORF2 potentially coded for a 132.41 kDa protein which contained the conserved motifs of the RNA-dependent RNA polymerase (RdRp). Phylogenetic analysis indicated that RsRV11 was clustered with RsRV-HN008 in a separate clade independent of other virus families. It implies that RsRV11, along with RsRV-HN008 possibly a new fungal virus taxa closed to the family Megabirnaviridae, and RsRV11 is a new member of mycoviruses.

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