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Query: UMLS:C0038362 (stomatitis)
 8,852 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mycoplasmas (Mollicutes) constitute a constant threat as insidious contaminants of animal cell cultures. They are responsible for myriad biochemical reactions associated with the cells they infect, and undoubtedly have been the source of metabolic and physiological activities attributed to their hosts. In an attempt to demonstrate a dsRNA-inducible double-stranded ribonuclease (dsRNase) in mammalian cells, comparable to that reported in avian cells, we discovered high levels of dsRNase "induced" by a particular stock of vesicular stomatitis virus. We now report that the double-stranded ribonuclease resulted from the activity of a contaminant in that stock--a "noncultivable" Mycoplasma hyorhinis. This report demonstrates the ubiquitous distribution of dsRNase among mycoplasmas, presents some characteristics of the enzyme and its production, and implicates once again mycoplasmas as contaminants of cell culture and potential perturbers of cellular physiology.
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PMID:Mycoplasmas produce double-stranded ribonuclease. 216 46

Previously we have shown that inhibition of replication of vesicular stomatitis virus in interferon-treated JLSV-11 cells is at least partly caused by impaired viral primary transcription. Here we report that subviral particles isolated from interferon-treated infected cells were deficient in mRNA synthesis in vitro compared with the particles isolated from untreated cells. This was due to the presence of an associated ribonuclease activity which hydrolyzed not only newly synthesized viral mRNAs but also exogenously added viral transcripts.
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PMID:Ribonuclease activity is associated with subviral particles isolated from interferon-treated vesicular stomatitis virus-infected cells. 244 94

The minus-sense RNA genome of measles virus serves as a template for synthesizing plus-sense RNAs of genomic length (antigenomes) and subgenomic length [poly(A)+ RNAs]. To elucidate how these different species are produced in vivo, RNA synthesized from the 3'-proximal N gene was characterized by Northern RNA blot and RNase protection analyses. The results showed that measles virus produced three size classes of plus-sense N-containing RNA species corresponding to monocistronic N RNA, bicistronic NP RNA, and antigenomes. Unlike vesicular stomatitis virus, measles virus does not produce a detectable free plus-sense leader RNA. Instead, although antigenomes invariably contain a leader sequence, monocistronic and bicistronic poly(A)+ N-containing RNAs are synthesized either without or with a leader sequence. We cloned and characterized a full-length cDNA representing a product of the latter type of synthesis. mRNAs and antigenomes appeared sequentially and in parallel with leaderless and leader-containing RNAs. These various RNA species accumulated concurrently throughout infection. However, cycloheximide preferentially inhibited accumulation of antigenomes and leader-containing RNA but not leaderless and subgenomic RNAs late in infection, suggesting that synthesis of the former RNA species requires a late protein function or a continuous supply of structural proteins or both. These results reveal a previously undescribed mechanism for RNA synthesis in measles virus.
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PMID:Measles virus synthesizes both leaderless and leader-containing polyadenylated RNAs in vivo. 247 Sep 23

A T1 ribonuclease fingerprinting study of a large number of virus isolates had previously demonstrated that considerable genetic variability existed among natural isolates of the vesicular stomatitis virus (VSV) New Jersey (NJ) serotype [S.T. Nichol (1988) J. Virol. 62, 572-579]. Based on these results, 34 virus isolates were chosen as representing the extent of genetic diversity within the VSV NJ serotype. We report the entire glycoprotein (G) gene nucleotide sequence and the deduced amino acid sequence for each of these viruses. Up to 19.8% G gene sequence differences could be seen among NJ serotype isolates. Analysis of the distribution of nucleotide substitutions relative to nucleotide codon position revealed that third position changes were distributed randomly throughout the gene. Third base changes constituted 84% of the observed nucleotide substitutions and affected 89% of the third base positions located in the G gene. Only three short oligonucleotide stretches of complete sequence conservation were observed. The remaining nucleotide changes located in the first and second positions were not distributed randomly, indicating that most of the amino acids coded by the G gene cannot be altered without reducing the fitness of the VSV NJ serotype viruses. Despite these constraints, up to 8.5% amino acid differences were observed between virus isolates. These differences were located throughout the G protein including regions adjacent to defined major antibody neutralization epitopes. Apparent clusters of amino acid substitutions were present in the hydrophobic signal sequence, transmembrane domain, and within the cytoplasmic domain of the G protein. A maximum parsimony analysis of the G gene nucleotide sequences allowed construction of a phylogram indicating the evolutionary relationship of these viruses. The VSV NJ serotype appears to contain at least three distinct lineages or subtypes. All recent virus isolates from the United States and Mexico are within subtype I and appear to have evolved from an ancestor more closely related to the Hazelhurst historic strain than other older strains. The implications of these findings for the evolution, epizootiology, and classification of these viruses are discussed.
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PMID:Glycoprotein evolution of vesicular stomatitis virus New Jersey. 253 83

RNase mapping was used to estimate the levels of unencapsidated Sendai virus plus-strand RNAs which cross the leader-NP junction relative to NP mRNA. Significant amounts of leader readthrough RNAs were found in Z strain-infected cells, similar to that described for the polR mutant of vesicular stomatitis virus, even though this strain is considered wild type. The levels of the readthrough RNAs detected fell sharply when progressively longer probes were used, unlike that of NP mRNA. These studies suggest that polymerases which read through the first junction terminate shortly afterwards in the absence of concurrent assembly of the nascent chain, whereas those which reinitiate at NP continue efficiently to the next junction. Reinitiation appears to be necessary to convert the polymerase to a mode in which elongation is independent of concurrent assembly. Concurrent assembly appears to be required not only for the polymerase to read through the junction efficiently, but also for it to continue elongation between junctions.
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PMID:Modified model for the switch from Sendai virus transcription to replication. 253 96

To determine the pattern of alternative splicing at the 5' end of class I genes, the 3' splice sites bordering exon 2 of the H-2Dd and H-2Kd genes were mutated from AG to GG (H-2Dd) or CG (H-2Kd). The mutant genes were transfected into L cells, and RNA from clones expressing these Ag was used for analysis by RNase and S1 nuclease mapping techniques. The first intervening sequence of both class I genes contains several potential 3' splice acceptor sites. However, a clear preference for only one site was detected in each of the H-2Dd and H-2Kd mRNA. Examination of the endogenous H-Dd and H-2Kd class I transcripts in normal murine tissues and in tumors demonstrated that the alternatively spliced mRNAs were produced, but at a low frequency. Infection of transfected L cells or tumor lines with vesicular stomatitis virus altered the level of differentially spliced message in these cells.
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PMID:Mutation of 3' splice sites in two different class I genes results in different usage of cryptic splice sites. 254 75

The interactions between the nucleocapsid protein N and either RNA or the phosphoprotein NS of vesicular stomatitis virus (VSV) were studied by the transcription of N and NS mRNAs from SP6 vectors, followed by translation in a rabbit reticulocyte lysate. Nascent N protein bound tightly to added labeled RNA, as well as to endogenous RNA in the reticulocyte lysate. This binding was demonstrated by three independent techniques. First, labeled N protein and labeled RNA migrated identically as a series of sharp, closely spaced bands in a nondenaturing gel system. Second, translated N protein behaved as a stable ribonucleoprotein complex in CsCl gradients and sedimented to the same density as the authentic N-RNA template of VSV. Third, translated N protein protected a series of labeled RNA fragments from digestion by RNase A. None of the three RNA-binding criteria was satisfied by either translated NS protein or two deletion mutants of N protein or by other components of the reticulocyte lysate. The evidence suggests that the observed binding of RNA by nascent N was not RNA sequence specific, in contrast to the encapsidation process during VSV replication. Moreover, the prior formation of N-NS complexes totally abolished the observed binding of RNA by N. Thus, we propose that NS may be responsible for conferring the sequence specificity of the RNA binding that occurs during VSV genome replication.
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PMID:Complex formation with vesicular stomatitis virus phosphoprotein NS prevents binding of nucleocapsid protein N to nonspecific RNA. 283 93

The RNA genomes of 43 vesicular stomatitis virus (VSV) isolates of the New Jersey (NJ) serotype were T1-ribonuclease fingerprinted to compare the extent of genetic diversity of virus from regions of epizootic and enzootic disease activity. Forty of these viruses were obtained from Central America during 1982 to 1985. The other three were older isolates, including a 1970 isolate from Culex nigripalpus mosquitos in Guatemala, a 1960 bovine isolate from Panama, and a 1976 isolate from mosquitos (Mansonia indubitans) in Ecuador. The data indicate that extensive genetic diversity exists among virus isolates from this predominantly enzootic disease zone. Six distinct T1 fingerprint groups were identified for the Central American VSV NJ isolates from 1982 to 1985. The 1960 VSV NJ isolate from Panama and the 1976 isolate from Ecuador formed two additional distinct fingerprint groups. This finding is in sharp contrast to the relatively close genetic relationship existing among VSV NJ isolates obtained from predominantly epizootic disease areas of the United States and Mexico during the same period (S. T. Nichol, J. Virol. 61:1029-1036, 1987). In this previous study, RNA genome T1 fingerprint differences were observed among isolates from different epizootics; however, the isolates were all clearly members of one large T1 fingerprint group. The eight T1 fingerprint groups described here for Central American and Ecuadorian viruses are distinct from those characterized earlier for virus isolates from the United States and Mexico and for the common laboratory virus strains Ogden and Hazelhurst. Despite being isolated 14 years earlier, the 1970 insect isolate from Guatemala is clearly a member of one of the 1982 to 1985 Central American virus fingerprint groups. This indicates that although virus genetic diversity in the region is extensive, under certain natural conditions particular virus genotypes can be relatively stably maintained for an extended period. The implications of these findings for the evolution of VSV NJ and epizootiology of the disease are discussed.
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PMID:Genetic diversity of enzootic isolates of vesicular stomatitis virus New Jersey. 289 61

The leader RNA transcript of vesicular stomatitis virus inhibits transcription of the adenovirus major late promoter and virus-associated genes in a soluble HeLa cell transcription system. We examined the specific nucleotide sequence involved and the potential role of leader-protein interactions in this inhibition of RNA polymerase II- and III-directed transcription. Using synthetic oligodeoxynucleotides homologous to regions of the leader RNA molecule, we extend our previous results (B.W. Grinnell and R.R. Wagner, Cell 36:533-543, 1984) that suggest a role for the AU-rich region of the leader RNA or the homologous AT region of a cloned cDNA leader in the inhibition of DNA-dependent transcription. Our results indicate that a short nucleotide sequence (AUUAUUA) or its deoxynucleotide homolog (ATTATTA) appears to be the minimal requirement for the leader RNA to inhibit transcription by both RNA polymerases, but sequences flanking both sides of this region increase the inhibitory activity. Nucleotide changes in the homologous AT-rich region drastically decrease the transcriptional inhibitory activity. Leader RNAs from wild-type virus, but not from a 5'-defective interfering particle, form a ribonuclease-resistant, protease-sensitive ribonucleoprotein complex in the soluble HeLa cell extract. Several lines of evidence suggest that the leader RNA specifically interacts with a 65,000-dalton (65K) cellular protein. In a fractionated cell extract, only those fractions containing this 65K protein could reverse the inhibition of DNA-dependent RNA synthesis by the plus-strand vesicular stomatitis virus leader RNA or by homologous DNA. In studies with synthetic oligodeoxynucleotides homologous to leader RNA sequences, only those oligonucleotides containing the inhibitory sequence were able to bind to a gradient fraction containing the 65K protein.
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PMID:Inhibition of DNA-dependent transcription by the leader RNA of vesicular stomatitis virus: role of specific nucleotide sequences and cell protein binding. 301 5

The phosphorylation and transcriptional competence of the free cytoplasmic form and the virion form of NS protein of vesicular stomatitis virus (VSV-Indiana/Mudd-Summers) were compared. NS protein is known to exist in two distinct phosphorylated states, NS1 and NS2, that are resolvable by gel electrophoresis. In vitro phosphorylation of virion NS protein by the viral L protein-associated protein kinase resulted in the phosphorylation of both NS1 and NS2. However, in the presence of the N-RNA complex, the NS2 form was preferentially phosphorylated. A cellular protein kinase activity, found in cytoplasmic extracts from VSV-infected or uninfected cells, preferentially phosphorylated NS1, which did not undergo dephosphorylation by cellular phosphatase and also did not convert to NS2. In contrast, the virion or cellular NS2 which had been phosphorylated in vivo or in vitro could be rapidly dephosphorylated by a cellular phosphatase. Cytoplasmic NS protein was found to be fully capable of binding to the virion N-RNA template, and in conjunction with L protein, it participated in synthesis of the leader RNA and five mRNA species of VSV. Moreover, under these conditions, neither cellular phosphatase nor cellular ribonuclease was able to bind to reconstituted nucleocapsids. Binding of cytoplasmic NS to the virion N-RNA template in the presence of L protein resulted in a large and preferential enhancement of NS2 phosphorylation. A protein kinase activity, which phosphorylated NS protein in vitro, was found to be associated with the N-RNA template. This activity appeared to be very tightly bound to N-RNA and exhibited absolute specificity for NS protein of the homologous serotype.
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PMID:Phosphoprotein NS of vesicular stomatitis virus: phosphorylated states and transcriptional activities of intracellular and virion forms. 302 Jul 80


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