Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.7.6 (RNA polymerase)
34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The in vitro activity of the ribonucleoprotein-dependent RNA transcriptase of vesicular stomatitis virions was found to be completely inhibited by low concentrations of aurintricarboxylic acid (ATA) and polyethylene sulfonic acid (PES) when these inhibitors were added before the start of the RNA polymerase reaction. However, if RNA synthesis was allowed to occur before ATA or PES was added, RNA synthesis continued for a short time (10 min or less) in the presence of either inhibitor at a concentration which completely inhibited uninitiated enzyme. The ability to continue to synthesize RNA in the presence of ATA or PES only developed if all four nucleoside triphosphates were present during the preincubation period prior to the addition of the inhibitors. The protection was apparently not due to the released products of RNA polymerization. The results are interpreted as indicating that ATA and PES probably inhibit some reaction other than elongation of RNA chains, and this reaction might be one involved at or near initiation sites.
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PMID:Inhibition by aurintricarboxylic acid and polyethylene sulfonate of RNA transcription of vesicular stomatitis virus. 17 45

The response of mouse L cells to infection with wild-type (wt) and temperature-sensitive (ts) mutants of vesicular stomatitis virus was monitored by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to delineate the synthesis of host cell and viral proteins. Experiments utilized transcriptase mutants of complementation group I (ts114 and ts13), a group IV mutant (ts44) that is restricted in total RNA synthesis (RNA-1) but not in primary transcription, and a group II mutant (ts52) variably restricted in RNA synthesis (RNA +/-). L cells infected with ts mutants at permissive temperature exhibited the wt response of progressive inhibition of host cell protein synthesis accompanied by accumulation of all five viral proteins. Mutant ts44 (IV) also switched off cell protein synthesis at restrictive temperature and accumulated all five viral proteins, but with disproportionate ratios of N and G proteins. At restrictive temperature, cells infected with group I ts mutants failed to accumulate any viral protein and did not exhibit significant reduction in host cell protein synthesis. These data suggest that vesicular stomatitis virus inhibits cell protein synthesis at a stage of viral infection after transcription and possibly translation but preceding replication of progeny viral RNA.
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PMID:Differential inhibition of host protein synthesis in L cells infected with RNA - temperature-sensitive mutants of vesicular stomatitis virus. 17 96

In vitro transcriptase activity of three group I temperature-sensitive (ts) mutants of vesicular stomatitis virus restricted at 39 C was restored by L-protein fractions derived from wild-type (wt) vesicular stomatitis virion nucleo-capsids. Soluble NS protein from wt nucleocapsids did not reconstitute restricted transcriptions of the group I RNA-ts mutants. NS protein activity, but not L protein activity, was purified from the group I ts mutants; this NS fraction always displayed the wt phenotype in reconstitution assays. Neither the L nor the NS protein was capable of restoring the defective transcriptive activity of the group IV vesicular stomatitis virus mutant ts W16B.
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PMID:RNA- temperature-sensitive mutants of vesicular stomatitis virus: L-protein thermosensitivity accounts for transcriptase restriction of group I mutants. 17

The RNA-dependent RNA polymerase associated with vesicular stomatitis virus was isolated to apparent homogeneity by a newly developed procedure, which includes stepwise removal of proteins from virions by successive treatment with high concentrations of cesium sulfate and cesium chloride, followed by glycerol gradient centrifugation or chromatography on phosphocellulose or DEAE-Sephadex column. The polymerase thus purified contained L (large protein) and NS proteins as the intrinsic subunits and multiple species of enzyme were found which differ in the molar ratio of L to NS. Since the enzyme with the highest activity was composed of equimolar amounts of the two subunits and exhibited the sedimentation coefficient of approximately 11 S in a buffer containing 0.2 M NaCl, the structure of active protomer was suggested to be (L)1(NS)1. In accordance with this conclusion, enzyme preparations deficient in the content of NS protein, were activated by the addition of preparations deficient in the content of NS protein. The purified RNA polymerase catalyzed the synthesis of poly(A), which was covalently attached to the 3' termini of RNA products, and RNA, only in the presence of all 4 substrates. The present finding might be the first which indicates that the transcriptase itself catalyzes post-transcriptional modification of mRNA by adding poly(A) sequences to the 3'-OH termini. The molecular mechanism of the switch from transcription to poly(A) synthesis, however, remains to be investigated.
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PMID:Function and structure of RNA polymerase from vesicular stomatitis virus. 18 23

The intracellular transcriptase complex of vesicular stomatitis virus-infected L cells synthesized RNA complementary to the entire infectious virus genome at either 37 degrees C or 28 degrees C in vitro. Not all sequences were present at the same frequency, however; copies of that segment of the genome common to the LT defective particles were present at 20 to 100 times higher frequently than copies of the genome segment common to the ST defective particle. The less frequent region was transcribed somewhat more effectively at 28 degrees C than at 37 degrees C. The results suggest that transcriptional regulation rather than selective degradation is responsible for the differential accumulation of RNA.
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PMID:Analysis of in vitro transcription products of intracellular vesicular stomatitis virus RNA polymerase. 18 12

The MF2 strain, a mouse myeloma derived cell line, was found to continuously produce C-type viral particles when maintained in tissue-culture. These cells when cultured in an ascitic form by injection to Balb/c mice lost this property. The ability to induce syncytia by cocultivation of the MF2 cell with XC-cells was shown to be related to the viral production. A DNA complementary to viral 70 S RNA was synthesized using the viral reverse-transcriptase endogenous activity. The quality of the probe is discussed and the expression of the viral genome among cellular poly A rich RNA varied concomitently to the syncytium inducing ability as evidenced by molecular hybridization experiments.
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PMID:XC-cell fusion induced by murine plasmocytoma cell. III. RNA gene expression correlated to syncytium formation. 18 44

The RNA polymerase in cells infected with three group I mutants of vesicular stomatitis virus has been examined. Mouse L cells were incubated at the permissive temperature (30 degrees C) for a few hours after infection to allow the development of secondary transcription. The temperature dependence of the secondary transcription system was determined from the incorporation of labelled uridine, in the presence of cycloheximide, at 30 and at 38 degrees C, the later temperature being non-permissive for viral replication. In cells infected with mutants W14, W28, and G11 at a low multiplicity (20 PFU/cells) secondary transcriptase activity was markedly temperature-sensitive after 3 and 5 h of infection at 30 degrees C. At a high multiplicity of infection (1000 PFU/cell) cells infected with W28 showed considerable RNA synthesis at 38 degrees C after 3 h at 30 degrees C. RNA synthesis was also observed in W28-infected cells in which protein synthesis was allowed to continue after the shift from 30 to 38 degrees C. In the latter two cases the RNA synthesized contained 12-18S species but little or no 30S mRNA.
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PMID:Temperature-sensitive mutants of vesicular stomatitis virus: viral RNA synthesis in cells infected with mutants belonging to complementation group I. 18 5

The ability of certain vesicular stomatitis virus (VSV; Indiana serotype) temperature-sensitive (ts) mutants to synthesize intracellular viral complementary RNA (vcRNA) at permissive or nonpermissive temperatures for productive infections has been investigated. Mutants belonging to complementation groups II, III, and V synthesize RNA at nonpermissive temperature in amounts essentially equivalent to that obtained at permissive temperatures. Mutant ts G I-114 possesses a thermolabile transcriptase and does not synthesize vcRNA at 40 degrees C; however, mutants ts O I-5, O I-53, O I-78, and O I-80 possess thermostabile transcriptases that are capable of some vcRNA synthesis at 40 degrees C. All five group I mutants are defective in their secondary transcription ability at 40 degrees C. Wild-type VSV New Jersey virus is able to complement the transcription defect of ts G I-114 at 40 degrees C. This complementation is inhibited by puromycin, suggesting that a viral gene product of VSV New Jersey (e.g., its transcriptase or a transcriptase component) is involved. Mokola virus is not able to complement the ts G I-114 defect, although Mokola does synthesize vcRNA in infected cells (in the presence or absence of cycloheximide).
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PMID:Synthesis of RNA by mutants of vesicular stomatitis virus (Indiana serotype) and the ability of wild-type VSV New Jersey to complement the VSV Indiana ts G I-114 transcription defect. 18 10

We established previously that the temperature-dependent host range mutant, td CE 3, of vesicular stomatitis virus (VSV) New Jersey possesses temperature-sensitive RNA transcriptase activity. In this paper, we describe dissociation and reconstitution experiments designed to determine which VSV polypeptide is affected by the td CE 3 mutation. Wild-type VSV New Jersey (ts+), the temperature-dependent host range mutant (td CE 3), and the revertant of this mutant (td CE/R1) were used. Transcribing nucleoprotein preparations, isolated from purified virus particles, were treated in the presence of digitonin with either 0.9 M LiCl to produce supernatants containing virtually only the L polypeptide or 2.0 M LiCl to produce ribonucleoprotein pellets containing only the polypeptides N and NS. Supernatant and pellet fractions synthesized either no or only trace amounts of RNA in vitro. Reconstitution of the supernatants with the pellets in all combinations at 31 degrees C restored much of the transcriptase activity of the transcribing nucleoprotein preparations. RNA synthesis occurred at 39 degrees C when the three pellets were reconstituted with wild-type and revertant supernatants. However, supernatant of the mutant td CE 3 reconstituted with any of the three pellets resulted in little or no detectable transcriptase activity at 39 degrees C. This implies that the polypeptide affected by the td CE 3 mutation is the L polypeptide.
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PMID:Temperature-dependent host range mutation in vesicular stomatitis virus affecting polypeptide L. 19 60

A template-dependent RNA polymerase has been isolated from poliovirus-infected cells by assaying for the ability of the enzyme to copy poly(A) complexed to an oligo(U) primer. The polymerase was solubilized with detergent, and RNA was removed by precipitation with 2 M LiCl. The solubilized polymerase required both poly(A) and oligo(U) for activity and was stimulated by Mg2+ but was inhibited by Mn2+. Poly(A)-oligo(U)-dependent poly(U) polymerase was not found in extracts of HeLa cells until about 2 hr after poliovirus infection, and then there was a linear increase in activity until about 5 hr. Analysis of the polymerase by glycerol gradient centrifugation showed that the majority of the activity sedimented at about 4 S, indicating that it was no longer complexed with high-molecular-weight RNA or cellular membranes. This poly(A)-oligo(U)-dependent polymerase activity could represent an important component of the poliovirus RNA-dependent RNA polymerase.
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PMID:Poliovirus-specific primer-dependent RNA polymerase able to copy poly(A). 19 96


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