Isolation of a dsRNA virus from Dipodascus (Endomyces) magnusii

1993 ◽  
Vol 23 (3) ◽  
pp. 219-222 ◽  
Author(s):  
Jozef Nosek ◽  
Dominik Filipp ◽  
Klára Bederkova ◽  
Peter Griač
Keyword(s):  
Dsrna Virus ◽  
Endomyces Magnusii

scholarly journals Atomic structure reveals the unique capsid organization of a dsRNA virus

2009 ◽  
Vol 106 (11) ◽  
pp. 4225-4230 ◽  
Author(s):  
J. Pan ◽  
L. Dong ◽  
L. Lin ◽  
W. F. Ochoa ◽  
R. S. Sinkovits ◽  
...  
Keyword(s):  
Atomic Structure ◽  
Dsrna Virus

Isolation and characterization of a new dsRNA virus fromWickerhamia fluorescens

1996 ◽  
Vol 41 (3) ◽  
pp. 223-227 ◽  
Author(s):  
M. Pospíšek ◽  
Z. Palková ◽  
J. Korb ◽  
D. Vaněk
Keyword(s):  
Dsrna Virus ◽  
Isolation And Characterization

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

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.

Evidence that the SKI antiviral system of Saccharomyces cerevisiae acts by blocking expression of viral mRNA

1993 ◽  
Vol 13 (7) ◽  
pp. 4331-4341
Author(s):  
W R Widner ◽  
R B Wickner
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Copy Number ◽  
Dsrna Virus ◽  
Cdna Clones ◽  
Viral Mrnas ◽  
Nucleolar Proteins ◽  
Toxin Secretion ◽  
Polymerase I ◽  
Beta Galactosidase

The SKI2 gene is part of a host system that represses the copy number of the L-A double-stranded RNA (dsRNA) virus and its satellites M and X dsRNA, of the L-BC dsRNA virus, and of the single-stranded replicon 20S RNA. We show that SKI2 encodes a 145-kDa protein with motifs characteristic of helicases and nucleolar proteins and is essential only in cells carrying M dsRNA. Unexpectedly, Ski2p does not repress M1 dsRNA copy number when M1 is supported by aN L-A cDNA clone; nonetheless, it did lower the levels of M1 dsRNA-encoded toxin produced. Since toxin secretion from cDNA clones of M1 is unaffected by Ski2p, these data suggest that Ski2p acts by specifically blocking translation of viral mRNAs, perhaps recognizing the absence of cap or poly(A). In support of this idea, we find that Ski2p represses production of beta-galactosidase from RNA polymerase I [no cap and no poly(A)] transcripts but not from RNA polymerase II (capped) transcripts.

scholarly journals A Novel Bipartite Double-Stranded RNA Mycovirus from the White Root Rot Fungus Rosellinia necatrix: Molecular and Biological Characterization, Taxonomic Considerations, and Potential for Biological Control

2009 ◽  
Vol 83 (24) ◽  
pp. 12801-12812 ◽  
Author(s):  
Sotaro Chiba ◽  
Lakha Salaipeth ◽  
Yu-Hsin Lin ◽  
Atsuko Sasaki ◽  
Satoko Kanematsu ◽  
...  
Keyword(s):  
Biological Control ◽  
Root Rot ◽  
Sequence Similarity ◽  
Peptide Mass Fingerprinting ◽  
Dsrna Virus ◽  
Rosellinia Necatrix ◽  
Virus Family ◽  
White Root Rot ◽  
Double Stranded Rna ◽  
Peptide Mass

ABSTRACT White root rot, caused by the ascomycete Rosellinia necatrix, is a devastating disease worldwide, particularly in fruit trees in Japan. Here we report on the biological and molecular properties of a novel bipartite double-stranded RNA (dsRNA) virus encompassing dsRNA-1 (8,931 bp) and dsRNA-2 (7,180 bp), which was isolated from a field strain of R. necatrix, W779. Besides the strictly conserved 5′ (24 nt) and 3′ (8 nt) terminal sequences, both segments show high levels of sequence similarity in the long 5′ untranslated region of approximately 1.6 kbp. dsRNA-1 and -2 each possess two open reading frames (ORFs) named ORF1 to -4. Although the protein encoded by 3′-proximal ORF2 on dsRNA-1 shows sequence identities of 22 to 32% with RNA-dependent RNA polymerases from members of the families Totiviridae and Chrysoviridae, the remaining three virus-encoded proteins lack sequence similarities with any reported mycovirus proteins. Phylogenetic analysis showed that the W779 virus belongs to a separate clade distinct from those of other known mycoviruses. Purified virions ∼50 nm in diameter consisted of dsRNA-1 and -2 and a single major capsid protein of 135 kDa, which was shown by peptide mass fingerprinting to be encoded by dsRNA-1 ORF1. We developed a transfection protocol using purified virions to show that the virus was responsible for reduction of virulence and mycelial growth in several host strains. These combined results indicate that the W779 virus is a novel bipartite dsRNA virus with potential for biological control (virocontrol), named Rosellinia necatrix megabirnavirus 1 (RnMBV1), that possibly belongs to a new virus family.

scholarly journals Evolutionary links among viruses of different categories revealed by dsRNA virus capsid structures

2008 ◽  
Vol 64 (a1) ◽  
pp. C58-C58
Author(s):  
F.A. Rey ◽  
S. Duquerroy ◽  
F. Coulibaly ◽  
J. Lepault ◽  
J. Navaza ◽  
...  
Keyword(s):  
Dsrna Virus ◽  
Virus Capsid

scholarly journals Reovirus Nonstructural Protein σNS Acts as an RNA Stability Factor Promoting Viral Genome Replication

2018 ◽  
Vol 92 (15) ◽  
Author(s):  
Paula F. Zamora ◽  
Liya Hu ◽  
Jonathan J. Knowlton ◽  
Roni M. Lahr ◽  
Rodolfo A. Moreno ◽  
...  
Keyword(s):  
Virus Replication ◽  
Viral Genome ◽  
Nonstructural Protein ◽  
Dsrna Virus ◽  
Genome Replication ◽  
Nonstructural Proteins ◽  
Content Type ◽  
The Family ◽  
Viral Genome Replication

ABSTRACTViral nonstructural proteins, which are not packaged into virions, are essential for the replication of most viruses. Reovirus, a nonenveloped, double-stranded RNA (dsRNA) virus, encodes three nonstructural proteins that are required for viral replication and dissemination in the host. The reovirus nonstructural protein σNS is a single-stranded RNA (ssRNA)-binding protein that must be expressed in infected cells for production of viral progeny. However, the activities of σNS during individual steps of the reovirus replication cycle are poorly understood. We explored the function of σNS by disrupting its expression during infection using cells expressing a small interfering RNA (siRNA) targeting the σNS-encoding S3 gene and found that σNS is required for viral genome replication. Using complementary biochemical assays, we determined that σNS forms complexes with viral and nonviral RNAs. We also discovered, usingin vitroand cell-based RNA degradation experiments, that σNS increases the RNA half-life. Cryo-electron microscopy revealed that σNS and ssRNAs organize into long, filamentous structures. Collectively, our findings indicate that σNS functions as an RNA-binding protein that increases the viral RNA half-life. These results suggest that σNS forms RNA-protein complexes in preparation for genome replication.IMPORTANCEFollowing infection, viruses synthesize nonstructural proteins that mediate viral replication and promote dissemination. Viruses from the familyReoviridaeencode nonstructural proteins that are required for the formation of progeny viruses. Although nonstructural proteins of different viruses in the familyReoviridaediverge in primary sequence, they are functionally homologous and appear to facilitate conserved mechanisms of dsRNA virus replication. Usingin vitroand cell culture approaches, we found that the mammalian reovirus nonstructural protein σNS binds and stabilizes viral RNA and is required for genome synthesis. This work contributes new knowledge about basic mechanisms of dsRNA virus replication and provides a foundation for future studies to determine how viruses in the familyReoviridaeassort and replicate their genomes.

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