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The genome organization of the Nidovirales: similarities and differences between arteri-, toro-, and coronaviruses
- Semin Virol
, 1997
"... Viruses in the families Arteriviridae and Coronaviridae have enveloped virions which contain nonseg-mented, positive-stranded RNA, but the constituent genera differ markedly in genetic complexity and virion structure. Nevertheless, there are striking resemblances among the viruses in the organizatio ..."
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Cited by 49 (11 self)
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Viruses in the families Arteriviridae and Coronaviridae have enveloped virions which contain nonseg-mented, positive-stranded RNA, but the constituent genera differ markedly in genetic complexity and virion structure. Nevertheless, there are striking resemblances among the viruses in the organization and expression of their genomes, and sequence conservation among the polymerase polyproteins strongly suggests that they have a common ancestry. On this basis, the International Committee on Taxonomy of Viruses recently established a new order, Nidovirales, to contain the two families. Here, the common traits and distinguishing features of the Nidovirales are reviewed. r 1997 Academic Press KEY WORDS: arterivirus; coronavirus; torovirus; polyprotein processing; RNA recombination.
Porcine reproductive and respiratory syndrome virus comparison: divergent evolution on two continents
- J
, 1999
"... This article cites 64 articles, 31 of which can be accessed free ..."
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Cited by 47 (7 self)
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This article cites 64 articles, 31 of which can be accessed free
Characterization of an equine arteritis virus replicase mutant defective in subgenomic mRNA synthesis
- J
, 1999
"... Equine arteritis virus (EAV) is a positive-stranded RNA virus that synthesizes a 5*- and 3*-coterminal nested set of six subgenomic mRNAs. These mRNAs all contain a common leader sequence which is derived from the 5 * end of the genome. Subgenomic mRNA transcription and genome replication are direct ..."
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Cited by 6 (5 self)
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Equine arteritis virus (EAV) is a positive-stranded RNA virus that synthesizes a 5*- and 3*-coterminal nested set of six subgenomic mRNAs. These mRNAs all contain a common leader sequence which is derived from the 5 * end of the genome. Subgenomic mRNA transcription and genome replication are directed by the viral replicase, which is expressed in the form of two polyproteins and subsequently processed into smaller non-structural proteins (nsps). During the recent construction of an EAV infectious cDNA clone (pEAV030 [L. C.
Replication of murine coronavirus defective interfering RNA from negative-strand transcripts
- J
, 1996
"... transcripts. interfering RNA from negative-strand Replication of murine coronavirus defective ..."
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Cited by 5 (3 self)
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transcripts. interfering RNA from negative-strand Replication of murine coronavirus defective
Nidovirus transcription: how to make sense...?
"... Many positive-stranded RNA viruses use subgenomic mRNAs to express part of their genetic information. To produce structural and accessory proteins, members of the order Nidovirales (corona-, toro-, arteri- and roniviruses) generate a 39 co-terminal nested set of at least three and often seven to nin ..."
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Many positive-stranded RNA viruses use subgenomic mRNAs to express part of their genetic information. To produce structural and accessory proteins, members of the order Nidovirales (corona-, toro-, arteri- and roniviruses) generate a 39 co-terminal nested set of at least three and often seven to nine mRNAs. Coronavirus and arterivirus subgenomic transcripts are not only 39 coterminal but also contain a common 59 leader sequence, which is derived from the genomic 59 end. Their synthesis involves a process of discontinuous RNA synthesis that resembles similarityassisted RNA recombination. Most models proposed over the past 25 years assume co-transcriptional fusion of subgenomic RNA leader and body sequences, but there has been controversy over the question of whether this occurs during plus- or minus-strand synthesis. In the latter model, which has now gained considerable support, subgenomic mRNA synthesis takes place from a complementary set of subgenome-size minus-strand RNAs, produced by discontinuous minus-strand synthesis. Sense–antisense base-pairing interactions between short conserved sequences play a key regulatory role in this process. In view of the presumed common ancestry of nidoviruses, the recent finding that ronivirus and torovirus mRNAs do not contain a common 59 leader sequence is surprising. Apparently, major mechanistic differences must exist between
Multigene RNA Vector Based on Coronavirus Transcription
, 2003
"... Coronavirus genomes are the largest known autonomously replicating RNAs with a size of ca. 30 kb. They are of positive polarity and are translated to produce the viral proteins needed for the assembly of an active replicase-transcriptase complex. In addition to replicating the genomic RNA, a key fea ..."
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Coronavirus genomes are the largest known autonomously replicating RNAs with a size of ca. 30 kb. They are of positive polarity and are translated to produce the viral proteins needed for the assembly of an active replicase-transcriptase complex. In addition to replicating the genomic RNA, a key feature of this complex is a unique transcription process that results in the synthesis of a nested set of six to eight subgenomic mRNAs. These subgenomic mRNAs are produced in constant but nonequimolar amounts and, in general, each is translated to produce a single protein. To take advantage of these features, we have developed a multigene expression vector based on human coronavirus 229E. We have constructed a prototype RNA vector containing the 5 and 3 ends of the human coronavirus genome, the entire human coronavirus replicase gene, and three reporter genes (i.e., the chloramphenicol acetyltransferase [CAT] gene, the firefly luciferase [LUC] gene, and the green fluorescent protein [GFP] gene). Each reporter gene is located downstream of a human coronavirus transcription-associated sequence, which is required for the synthesis of individual subgenomic mRNAs. The transfection of vector RNA and human coronavirus nucleocapsid protein mRNA into BHK-21 cells resulted in the expression of the CAT, LUC, and GFP reporter proteins. Sequence analysis confirmed the synthesis of coronavirus-specific mRNAs encoding CAT, LUC, and GFP. In addition, we have shown that human corona-virus-based vector RNA can be packaged into virus-like particles that, in turn, can be used to transduce
CONTENT ALERTS
, 2003
"... This article cites 48 articles, 36 of which can be accessed free ..."
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Engineering the Transmissible Gastroenteritis Virus Genome as an Expression Vector Inducing Lactogenic Immunity
, 2002
"... The genome of the coronavirus transmissible gastroenteritis virus (TGEV) has been engineered as an expression vector with an infectious cDNA. The vector led to the efficient (>40 g/106 cells) and stable (>20 passages) expression of a heterologous gene (green fluorescent protein [GFP]), driven ..."
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The genome of the coronavirus transmissible gastroenteritis virus (TGEV) has been engineered as an expression vector with an infectious cDNA. The vector led to the efficient (>40 g/106 cells) and stable (>20 passages) expression of a heterologous gene (green fluorescent protein [GFP]), driven by the transcription-regulating sequences (TRS) of open reading frame (ORF) 3a inserted in the site previously occupied by the nonessential ORFs 3a and 3b. Expression levels driven by this TRS were higher than those of an expression cassette under the control of regulating sequences engineered with the N gene TRS. The recombinant TGEV including the GFP gene was still enteropathogenic, albeit with a 10- to 102-fold reduction in enteric tissue growth. Interestingly, a specific lactogenic immune response against the heterologous protein has been elicited in sows and their progeny. The engineering of an additional insertion site for the heterologous gene between viral genes N and 7 led to instability and to a new genetic organization of the 3 end of the recombinant viruses. As a consequence, a major species of subgenomic mRNA was generated from a TRS with the noncanonical core sequence 5-CUAAAA-3. Extension of the complementarity between the TRS and sequences at the 3 end of the viral leader was associated with transcriptional activation of noncanonical core sequences. The engineered vector led to expression levels as high as those of well-established vectors and seems very promising for the development of vaccines and, possibly, for gene therapy.
CONTENT ALERTS
, 2007
"... This article cites 68 articles, 46 of which can be accessed free ..."
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CONTENT ALERTS
, 2004
"... This article cites 49 articles, 29 of which can be accessed free ..."
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