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49
Virus-encoded proteinases and proteolytic processing in the Nidovirales
- J. Gen. Virol
, 2000
"... On the basis of similarities in their genome organization and replication strategy, RNA viruses can now be classified into ‘supergroups ’ that often include both animal and plant ..."
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Cited by 105 (29 self)
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On the basis of similarities in their genome organization and replication strategy, RNA viruses can now be classified into ‘supergroups ’ that often include both animal and plant
Strategy for Systematic Assembly of Large RNA and DNA Genomes: Transmissible Gastroenteritis Virus Model
, 2000
"... A systematic method was developed to assemble functional full-length genomes of large RNA and DNA viruses. Coronaviruses contain the largest single-stranded positive-polarity RNA genome in nature. The �30kb genome, coupled with regions of genomic instability, has hindered the development of a full-l ..."
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Cited by 56 (6 self)
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A systematic method was developed to assemble functional full-length genomes of large RNA and DNA viruses. Coronaviruses contain the largest single-stranded positive-polarity RNA genome in nature. The �30kb genome, coupled with regions of genomic instability, has hindered the development of a full-length infectious cDNA construct. We have assembled a full-length infectious construct of transmissible gastroenteritis virus (TGEV), an important pathogen in swine. Using a novel approach, six adjoining cDNA subclones that span the entire TGEV genome were isolated. Each clone was engineered with unique flanking interconnecting junctions which determine a precise systematic assembly with only the adjacent cDNA subclones, resulting in an intact TGEV cDNA construct of �28.5 kb in length. Transcripts derived from the full-length TGEV construct were infectious, and progeny virions were serially passaged in permissive host cells. Viral antigen production and subgenomic mRNA synthesis were evident during infection and throughout passage. Plaque-purified virus derived from the infectious construct replicated efficiently and displayed similar plaque morphology in permissive host cells. Host range phenotypes of the molecularly cloned and wild-type viruses were similar in cells of swine and feline origin. The recombinant viruses were sequenced across the unique interconnecting junctions, conclusively demonstrating the marker mutations and restriction sites that were engineered into the component clones. Full-length infectious constructs of TGEV will permit the precise genetic modification of the
Viral replicase gene products suffice for coronavirus discontinuous transcription
- J. Virol
, 2001
"... This article cites 28 articles, 22 of which can be accessed free ..."
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Cited by 33 (7 self)
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This article cites 28 articles, 22 of which can be accessed free
Heterologous gene expression from transmissible gastroenteritis virus replicon particles
- J
, 2002
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A novel severe acute respiratory syndrome coronavirus protein, U274, is transported to the cell surface and undergoes endocytosis
- J. Virol
, 2004
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Induction of apoptosis in murine coronavirus-infected cultured cells and demonstration of E protein as an apoptosis inducer
- J. Virol. 73:7853–7859. 5946 BANERJEE ET
, 1999
"... We demonstrated that infection of 17Cl-1 cells with the murine coronavirus mouse hepatitis virus (MHV) induced caspase-dependent apoptosis. MHV-infected DBT cells did not show apoptotic changes, indicating that apoptosis was not a universal mechanism of cell death in MHV-infected cells. Expression o ..."
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Cited by 25 (5 self)
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We demonstrated that infection of 17Cl-1 cells with the murine coronavirus mouse hepatitis virus (MHV) induced caspase-dependent apoptosis. MHV-infected DBT cells did not show apoptotic changes, indicating that apoptosis was not a universal mechanism of cell death in MHV-infected cells. Expression of MHV structural proteins by recombinant vaccinia viruses showed that expression of MHV E protein induced apoptosis in DBT cells, whereas expression of other MHV structural proteins, including S protein, M protein, N protein, and hemagglutinin-esterase protein, failed to induce apoptosis. MHV E protein-mediated apoptosis was suppressed by a high level of Bcl-2 oncogene expression. Our data showed that MHV E protein is a multifunctional protein; in addition to its known function in coronavirus envelope formation, it also induces apoptosis. Apoptosis (or programmed cell death) is an important pro-cess in the development and homeostasis of multicellular or-ganisms (18, 28, 43). In most cases, apoptosis is executed by activating a proteolytic system involving a family of proteases called caspases. Caspases participate in a cascade that is trig-gered in response to proapoptotic signals and culminates in cleavage of a set of proteins, resulting in cell death (12, 45).
Identification of a novel structural protein of arteriviruses
- J
, 1999
"... Arteriviruses are positive-stranded RNA viruses with an efficiently organized, polycistronic genome. A short region between the replicase gene and open reading frame (ORF) 2 of the equine arteritis virus (EAV) genome was previously assumed to be untranslated. However, here we report that this segmen ..."
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Cited by 20 (11 self)
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Arteriviruses are positive-stranded RNA viruses with an efficiently organized, polycistronic genome. A short region between the replicase gene and open reading frame (ORF) 2 of the equine arteritis virus (EAV) genome was previously assumed to be untranslated. However, here we report that this segment of the EAV genome contains the 5 * part of a novel gene (ORF 2a) which is conserved in all arteriviruses. The 3 * part of EAV ORF 2a overlaps with the 5 * part of the former ORF 2 (now renamed ORF 2b), which encodes the GS glycoprotein. Both ORF 2a and ORF 2b appear to be expressed from mRNA 2, which thereby constitutes the first proven example of a bicistronic mRNA in arteriviruses. The 67-amino-acid protein encoded by EAV ORF 2a, which we have provisionally named the envelope (E) protein, is very hydrophobic and has a basic C terminus. An E protein-specific antiserum was raised and used to demonstrate the expression of the novel gene in EAV-infected cells. The EAV E protein proved to be very stable, did not form disulfide-linked oligomers, and was not N-glycosylated. Immunofluorescence and immunoelectron microscopy studies showed that the E protein associates with intracellular membranes both in EAV-infected cells and upon independent expression. An analysis of purified EAV particles revealed that the E protein is a structural protein. By using reverse genetics, we demonstrated that both the EAV E and GS proteins are essential for the production of infectious progeny virus. Arteriviruses are enveloped, positive-stranded RNA viruses
Discontinuous subgenomic RNA synthesis in arteriviruses is guided by an RNA hairpin structure located in the genomic leader region
- J. Virol
, 2005
"... Nidoviruses produce an extensive 3�-coterminal nested set of subgenomic (sg) mRNAs, which are used to express structural proteins and sometimes accessory proteins. In arteriviruses and coronaviruses, these mRNAs contain a common 5 � leader sequence, derived from the genomic 5 � end. The joining of t ..."
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Cited by 16 (7 self)
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Nidoviruses produce an extensive 3�-coterminal nested set of subgenomic (sg) mRNAs, which are used to express structural proteins and sometimes accessory proteins. In arteriviruses and coronaviruses, these mRNAs contain a common 5 � leader sequence, derived from the genomic 5 � end. The joining of the leader sequence to different segments derived from the 3�-proximal part of the genome (mRNA bodies) presumably involves a unique mechanism of discontinuous minus-strand RNA synthesis in which base pairing between sense and antisense transcription-regulating sequences (TRSs) plays an essential role. The leader TRS is present in the loop of a hairpin structure that functions in sg mRNA synthesis. In this study, the minimal sequences in the 5�-proximal region of the Equine arteritis virus genome that are required for sg RNA synthesis were delimited through mutagenesis. A full-length cDNA clone was engineered in which this domain was duplicated, allowing us to make mutations and monitor their effects on sg RNA synthesis without seriously affecting genome replication and translation. The leader TRS present in the duplicated sequence was used and yielded novel sg mRNAs with significantly extended leaders. Our combined findings suggest that the leader TRS hairpin (LTH) and its immediate flanking sequences are essential for efficient sg RNA synthesis and form an independent functional entity that could be moved 300 nucleotides downstream of its original position in the genome. We hypothesize that a conformational switch in the LTH region regulates the role of the 5�-proximal
Biochemical characterization of the equine arteritis virus helicase suggests a close functional relationship between arterivirus and coronavirus helicases
- Journal of Virology
, 2000
"... This article cites 61 articles, 35 of which can be accessed free ..."
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Cited by 15 (12 self)
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This article cites 61 articles, 35 of which can be accessed free
Genetic, geographical and temporal variation of porcine reproductive and respiratory syndrome virus in Illinois
"... Porcine reproductive and respiratory syndrome virus (PRRSV) ORF5 gene sequences were generated by RT–PCR from 55 field isolates collected in Illinois and eastern Iowa. Spatial and temporal patterns of genetic variation in the virus were examined on a local geographical scale in order to test the hyp ..."
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Cited by 10 (3 self)
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Porcine reproductive and respiratory syndrome virus (PRRSV) ORF5 gene sequences were generated by RT–PCR from 55 field isolates collected in Illinois and eastern Iowa. Spatial and temporal patterns of genetic variation in the virus were examined on a local geographical scale in order to test the hypothesis that the genetic similarity of PRRSV isolates (measured as their percentage pairwise ORF5 nucleotide similarity) was positively correlated with their geographical proximity. Levels of genetic variability in the Illinois/eastern Iowa PRRSV sample were similar to levels of variability seen across broader geographical regions within North America. The genetic similarity of isolates did not correlate with their geographical distance. These results imply that the movement of PRRSV onto farms does not generally occur via distance-limited processes such as wind or wildlife vectors, but more typically occurs via the long-distance transport of animals or semen. Genetic distances between PRRSV isolates collected from the same farms at different times increased as the time separating the collection events increased. This result implies rapid movement of new genetic types of PRRSV into and out of farms. PRRSV ORF5 displayed a pattern of third-codon-position diversity bias that was not evident in a geographically comparable sample of pseudorabies virus (a swine alphaherpesvirus) gC gene sequences. This result provides evidence that PRRSV ORF5 is experiencing stabilizing selection against structural novelty. Despite high genetic variability at all geographical levels, PRRSV ORF5 nevertheless contained potentially antigenic regions that were invariant at the amino acid level. These regions should make effective vaccine targets if they prove to be immunogenic.
