Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.6 (RNA polymerase)
 34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rinderpest virus is a morbillivirus and is the causative agent of a widespread and important disease of cattle. The viral genome is a single strand of RNA in the negative sense. We have constructed plasmids containing cDNA copies of the 5' and 3' termini of the virus separated by a reporter gene and have shown that antigenome-sense RNA transcripts of these model genomes can be replicated, transcribed, and packaged by helper virus, both rinderpest virus and the related measles virus. Further, these genome analogs can be replicated and transcribed by viral proteins expressed from cDNA clones by using a recombinant vaccinia virus expressing T7 RNA polymerase (MVA-T7). Using this latter system, we have rescued live rinderpest virus from a full-length cDNA copy of the genome of the RBOK vaccine strain. The recombinant virus appears to grow in tissue culture identically to the original virus.
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PMID:Rescue of rinderpest virus from cloned cDNA. 899 50

Rinderpest (RP) and peste-des-petits-ruminants (PPR) are two important diseases of domestic ruminants. To improve on currently available vaccines against PPR, we have created cDNA copies of the RP virus genome in which either the fusion (F) or hemagglutinin (H) gene, or both, was replaced with the corresponding gene from PPR virus. It was necessary to develop a modified rescue system in which the T7 RNA polymerase was provided by a recombinant fowlpox virus and the entire rescue procedure took place in Vero cells before we could obtain live virus from these chimeric constructs. No virus was recovered when only one of the glycoprotein genes was changed, but a chimeric virus containing both F and H genes from PPR virus was reproducibly rescued from cDNA, indicating that a virus-specific functional interaction takes place between the F and H proteins. The rescued virus expressing the PPR glycoproteins grew more slowly in tissue culture than either parental virus and formed abnormally large syncytia. Goats infected with the chimera showed no adverse reaction, as assessed by clinical signs, temperature, leukocyte count, virus isolation, and serology, and were protected from subsequent challenge with wild-type PPR virus.
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PMID:Recovery and characterization of a chimeric rinderpest virus with the glycoproteins of peste-des-petits-ruminants virus: homologous F and H proteins are required for virus viability. 1098 48

Canine distemper virus (CDV) has been rescued from a full-length cDNA clone. Besides Measles virus (MV) and Rinderpest virus, a third morbillivirus is now available for genetic analysis using reverse genetics. A plasmid p(+)CDV was constructed by sequential cloning using the Onderstepoort vaccine strain large-plaque-forming variant. The presence of a T7 promoter allowed transcription of full-length antigenomic RNA by a T7 RNA polymerase, which was provided by a host range mutant of vaccinia virus (MVA-T7). Plasmids expressing the nucleocapsid protein, the phosphoprotein, and the viral RNA-dependent RNA polymerase, also under control of a T7 promoter, have been generated. Infection of HeLa cells with MVA-T7 and subsequent transfection of p(+)CDV plus the helper plasmids led to syncytium formation and release of infectious recombinant (r) CDV. Comparison of the rescued virus with the parental virus revealed no major differences in the progression of infection or in the shape and size of syncytia. A genetic tag, consisting of two nucleotide changes within the coding region of the L protein, has been identified in the rCDV genome. Expression by rCDV of all the major viral structural proteins has been demonstrated by immunofluorescence.
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PMID:Establishment of a rescue system for canine distemper virus. 1104 18

The RNA dependent RNA polymerase of Rinderpest virus consists of two subunits-the large protein (L) and the phosphoprotein (P), where L is thought to be responsible for the catalytic activities in association with P protein which plays multiple roles in transcription and replication. The nucleocapsid protein (N) is necessary for encapsidation of genomic RNA, which is required as N-P complex. To understand the different steps of transcription and replication as well as the roles played by the three proteins, an in vitro reconstitution system for RNA synthesis is necessary which is not available for any morbillivirus. We describe here, an in vitro reconstitution system for transcription and replication of Rinderpest virus utilizing a synthetic, positive sense N-RNA minigenome template, free of endogenous viral polymerase proteins and recombinant viral proteins (P+L and P+N) expressed in insect cells by recombinant baculoviruses. We show that although L-P complex is sufficient to synthesize negative sense minigenome RNA, soluble N protein is necessary for encapsidation of RNA as well as synthesis of (+) sense leader RNA and (+) sense minigenome RNA.
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PMID:Development of a reconstitution system for Rinderpest virus RNA synthesis in vitro. 1474 78

The RNA dependant RNA polymerase of negative sense RNA viruses is composed of two subunits - the Large protein (L) and the Phosphoprotein (P). These two proteins have to form a complex in order to carry out genome transcription and replication. Employing the baculovirus expression system, we demonstrate here, the specific in vivo interaction between the L and P proteins of Rinderpest virus and also the stabilization of L protein when it is present as L + P complex. The regions on either protein involved in such interaction has been studied using the yeast two-hybrid system which indicates that the P binding region resides within the amino terminal 380 amino acid residues of L protein. The L binding region on P protein has been mapped to lie within 347-490 amino acids.
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PMID:Rinderpest virus RNA polymerase subunits: mapping of mutual interacting domains on the large protein L and phosphoprotein p. 1497 16

The negative sense genome RNA of Rinderpest virus, a Paramyxoviridae, is encapsidated with the nucleocapsid protein N and serves as a template for the viral RNA dependent RNA polymerase for transcription and replication. The viral RNA polymerase consists of the large protein L and the phosphoprotein P functioning as the P-L complex. We provide in this report, evidences for specific binding of P protein of Rinderpest virus to the plus sense leader RNA depending on its phosphorylation status. We have also demonstrated that P protein is released from the le RNA:P protein complex upon phosphorylation in vitro. Finally, we have identified that the C-terminal 358-389 amino acid residues of P protein is involved in le RNA binding. The leader RNA binding may signify a hitherto unidentified role for P protein in the viral RNA synthesis. Moreover, our results indicate a possible role for P protein in the transcription-replication switch through leader RNA binding.
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PMID:Phosphoprotein P of Rinderpest virus binds to plus sense leader RNA: regulation by phosphorylation. 1524 56

The paramyxovirus P protein is an essential component of the transcriptase and replicase complex along with L protein. In this article, we have examined the functional roles of different domains of P proteins of two closely related morbilliviruses, Rinderpest virus (RPV) and Peste des petits ruminants virus (PPRV). The PPRV P protein physically interacts with RPV L as well as RPV N protein when expressed in transfected cells, as shown by co-immunoprecipitation. The heterologous L-P complex is biologically active when tested in a RPV minigenome replication/transcription system, only when used with PPRV N protein but not with RPV N protein. Employing chimeric PPRV/RPV cDNAs having different coding regions of P protein in the minigenome replication/transcription system, we identified a region between 290 and 346 aa in RPV P protein necessary for transcription of the minigenome.
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PMID:Identification of functional domains of phosphoproteins of two morbilliviruses using chimeric proteins. 1842 68

Rinderpest virus belongs to the family of Paramyxoviridae, consisting of non-segmented negative sense RNA viruses. Viral transcription and replication are carried out by the RNA dependent RNA polymerase L protein which functions together with P protein as L-P complex. The exact events triggering the polymerase complex from transcription to replication function is poorly understood. In the present work, an in vitro transcription system has been described with partially purified L-P complex expressed in insect cells and viral genomic RNA. The relative abundance of each species of mRNA synthesized in vitro decreased from the 3' end of the genome to the 5' end similar to their abundance in virus infected cells. Recombinant L-P complex was unable to synthesize leader RNA suggesting the initiation of transcription from gene start site and not at the 3' end of the genome.
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PMID:Recombinant L and P protein complex of Rinderpest virus catalyses mRNA synthesis in vitro. 1843 Apr 84

The large protein L of negative-sense RNA viruses is a multifunctional protein involved in transcription and replication of genomic RNA. It also possesses enzymatic activities involved in capping and methylation of viral mRNAs. The pathway for mRNA capping followed by the L protein of the viruses in the Morbillivirus genus has not been established, although it has been speculated that these viruses may follow the unconventional capping pathway as has been shown for some viruses of Rhabdoviridae family. We had earlier shown that the large protein L of Rinderpest virus expressed as recombinant L-P complex in insect cells as well as the ribonucleoprotein complex from purified virus possesses RNA triphosphatase (RTPase) and guanylyltransferase activities, in addition to RNA dependent RNA polymerase activity. In the present work, we demonstrate that RTPase as well as nucleoside triphosphatase (NTPase) activities are exhibited by a subdomain of the L protein in the C terminal region (a.a. 1640-1840). The RTPase activity depends absolutely on a divalent cation, either magnesium or manganese. Both the RTPase and NTPase activities of the protein show dual metal specificity. Two mutant proteins having alanine mutations in the glutamic acid residues in motif-A of the RTPase domain did not show RTPase activity, while exhibiting reduced NTPase activity suggesting overlapping active sites for the two enzymatic functions. The RTPase and NTPase activities of the L subdomain resemble those of the Vaccinia capping enzyme D1 and the baculovirus LEF4 proteins.
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PMID:A carboxy terminal domain of the L protein of rinderpest virus possesses RNA triphosphatase activity - The first enzyme in the viral mRNA capping pathway. 2616 20