scholarly journals Detection of Single Influenza Viral RNA in Cells Using a Polymeric Sequence Probe

2012 ◽  
Vol 84 (19) ◽  
pp. 8118-8121 ◽  
Author(s):  
Suxian Huang ◽  
Chaoran Yu ◽  
Genhong Cheng ◽  
Yong Chen
Keyword(s):  
Viral Rna ◽  
Sequence Probe ◽  
In Cells

Viral RNA Subunits in Cells Transformed by RNA Tumor Viruses

Science ◽  
1972 ◽  
Vol 176 (4042) ◽  
pp. 1418-1420 ◽  
Author(s):  
N. Tsuchida ◽  
M. S. Robin ◽  
M. Green
Keyword(s):  
Viral Rna ◽  
Tumor Viruses ◽  
Rna Tumor Viruses ◽  
In Cells

SYNTHESIS OF VIRAL RNA IN CELLS INFECTED BY AVIAN SARCOMA VIRUSES

1976 ◽  
pp. 1-20 ◽  
Author(s):  
J. Michael Bishop ◽  
Chun-Tsan Deng ◽  
Brian W.J. Mahy ◽  
Nancy Quintrell ◽  
Edward Stavnezer ◽  
...  
Keyword(s):  
Viral Rna ◽  
Avian Sarcoma ◽  
In Cells

scholarly journals The Interferon-Induced Exonuclease ISG20 Exerts Antiviral Activity through Upregulation of Type I Interferon Response Proteins

mSphere ◽  
2018 ◽  
Vol 3 (5) ◽  
Author(s):  
Christopher M. Weiss ◽  
Derek W. Trobaugh ◽  
Chengqun Sun ◽  
Tiffany M. Lucas ◽  
Michael S. Diamond ◽  
...  
Keyword(s):  
Virus Replication ◽  
Type I Interferon ◽  
Rna Virus ◽  
Ectopic Expression ◽  
Viral Rna ◽  
Interferon Response ◽  
Type I ◽  
Venezuelan Equine Encephalitis ◽  
Wild Type ◽  
In Cells

ABSTRACTType I interferon (IFN)-stimulated genes (ISGs) have critical roles in inhibiting virus replication and dissemination. Despite advances in understanding the molecular basis of ISG restriction, the antiviral mechanisms of many remain unclear. The 20-kDa ISG ISG20 is a nuclear 3′–5′ exonuclease with preference for single-stranded RNA (ssRNA) and has been implicated in the IFN-mediated restriction of several RNA viruses. Although the exonuclease activity of ISG20 has been shown to degrade viral RNAin vitro, evidence has yet to be presented that virus inhibition in cells requires this activity. Here, we utilized a combination of an inducible, ectopic expression system and newly generatedIsg20−/−mice to investigate mechanisms and consequences of ISG20-mediated restriction. Ectopically expressed ISG20 localized primarily to Cajal bodies in the nucleus and restricted replication of chikungunya and Venezuelan equine encephalitis viruses. Although restriction by ISG20 was associated with inhibition of translation of infecting genomic RNA, degradation of viral RNAs was not observed. Instead, translation inhibition of viral RNA was associated with ISG20-induced upregulation of over 100 other genes, many of which encode known antiviral effectors. ISG20 modulated the production of IFIT1, an ISG that suppresses translation of alphavirus RNAs. Consistent with this observation, the pathogenicity of IFIT1-sensitive alphaviruses was increased inIsg20−/−mice compared to that of wild-type viruses but not in cells ectopically expressing ISG20. Our findings establish an indirect role for ISG20 in the early restriction of RNA virus replication by regulating expression of other ISGs that inhibit translation and possibly other activities in the replication cycle.IMPORTANCEThe host immune responses to infection lead to the production of type I interferon (IFN), and the upregulation of interferon-stimulated genes (ISGs) reduces virus replication and virus dissemination within a host. Ectopic expression of the interferon-induced 20-kDa exonuclease ISG20 suppressed replication of chikungunya virus and Venezuelan equine encephalitis virus, two mosquito-vectored RNA alphaviruses. Since the replication of alphavirus genomes occurs exclusively in the cytoplasm, the mechanism of nucleus-localized ISG20 inhibition of replication is unclear. In this study, we determined that ISG20 acts as a master regulator of over 100 genes, many of which are ISGs. Specifically, ISG20 upregulated IFIT1 genes and inhibited translation of the alphavirus genome. Furthermore, IFIT1-sensitive alphavirus replication was increased inIsg20−/−mice compared to the replication of wild-type viruses but not in cells ectopically expressing ISG20. We propose that ISG20 acts as an indirect regulator of RNA virus replication in the cytoplasm through the upregulation of many other ISGs.

A selective temperature-sensitive defect in viral RNA expression in cells infected with a ts transformation mutant of murine sarcoma virus

Cell ◽  
1981 ◽  
Vol 25 (1) ◽  
pp. 37-46 ◽  
Author(s):  
Jacqueline Peltier Horn ◽  
T.Gordon Wood ◽  
Edwin C. Murphy ◽  
Donald G. Blair ◽  
Ralph B. Arlinghaus
Keyword(s):  
Viral Rna ◽  
Temperature Sensitive ◽  
Rna Expression ◽  
Murine Sarcoma Virus ◽  
Sarcoma Virus ◽  
Murine Sarcoma ◽  
In Cells

scholarly journals Impaired hyperphosphorylation of rotavirus NSP5 in cells depleted of casein kinase 1α is associated with the formation of viroplasms with altered morphology and a moderate decrease in virus replication

2007 ◽  
Vol 88 (10) ◽  
pp. 2800-2810 ◽  
Author(s):  
Michela Campagna ◽  
Mauricio Budini ◽  
Francesca Arnoldi ◽  
Ulrich Desselberger ◽  
Jorge E. Allende ◽  
...  
Keyword(s):  
Cytoplasmic Inclusion ◽  
Rna Replication ◽  
Viral Rna ◽  
Structural Protein ◽  
Cytoplasmic Inclusion Bodies ◽  
Replicative Cycle ◽  
In Cells

The rotavirus (RV) non-structural protein 5, NSP5, is encoded by the smallest of the 11 genomic segments and localizes in ‘viroplasms’, cytoplasmic inclusion bodies in which viral RNA replication and packaging take place. NSP5 is essential for the replicative cycle of the virus because, in its absence, viroplasms are not formed and viral RNA replication and transcription do not occur. NSP5 is produced early in infection and undergoes a complex hyperphosphorylation process, leading to the formation of proteins differing in electrophoretic mobility. The role of hyperphosphorylation of NSP5 in the replicative cycle of rotavirus is unknown. Previous in vitro studies have suggested that the cellular kinase CK1α is responsible for the NSP5 hyperphosphorylation process. Here it is shown, by means of specific RNA interference, that in vivo, CK1α is the enzyme that initiates phosphorylation of NSP5. Lack of NSP5 hyperphosphorylation affected neither its interaction with the virus VP1 and NSP2 proteins normally found in viroplasms, nor the production of viral proteins. In contrast, the morphology of viroplasms was altered markedly in cells in which CK1α was depleted and a moderate decrease in the production of double-stranded RNA and infectious virus was observed. These data show that CK1α is the kinase that phosphorylates NSP5 in virus-infected cells and contribute to further understanding of the role of NSP5 in RV infection.

scholarly journals The N-Terminal Domain of PMTV TGB1 Movement Protein Is Required for Nucleolar Localization, Microtubule Association, and Long-Distance Movement

2010 ◽  
Vol 23 (11) ◽  
pp. 1486-1497 ◽  
Author(s):  
Kathryn M. Wright ◽  
Graham H. Cowan ◽  
Nina I. Lukhovitskaya ◽  
Jens Tilsner ◽  
Alison G. Roberts ◽  
...  
Keyword(s):  
Amino Acids ◽  
Fluorescent Protein ◽  
Movement Protein ◽  
Leading Edge ◽  
Epidermal Cells ◽  
Viral Rna ◽  
Nucleolar Localization ◽  
Long Distance ◽  
Long Distance Movement ◽  
In Cells

The triple-gene-block (TGB)1 protein of Potato mop-top virus (PMTV) was fused to fluorescent proteins and expressed in epidermal cells of Nicotiana benthamiana under the control of the 35S promoter. TGB1 fluorescence was observed in the cytoplasm, nucleus, and nucleolus and occasionally associated with microtubules. When expressed from a modified virus (PMTV.YFP-TGB1) which formed local lesions but was not competent for systemic movement, yellow fluorescent protein (YFP)-TGB1 labeled plasmodesmata in cells at the leading edge of the lesion and plasmodesmata, microtubules, nuclei, and nucleoli in cells immediately behind the leading edge. Deletion of 84 amino acids from the N-terminus of unlabeled TGB1 within the PMTV genome abolished movement of viral RNA to noninoculated leaves. When the same deletion was introduced into PMTV.YFP-TGB1, labeling of microtubules and nucleoli was abolished. The N-terminal 84 amino acids of TGB1 were fused to green fluorescent protein (GFP) and expressed in epidermal cells where GFP localized strongly to the nucleolus (not seen with unfused GFP), indicating that these amino acids contain a nucleolar localization signal; the fusion protein did not label microtubules. This is the first report of nucleolar and microtubule association of a TGB movement protein. The results suggest that PMTV TGB1 requires interaction with nuclear components and, possibly, microtubules for long-distance movement of viral RNA.

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