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)

In cultures of Ly cells treated with 10 or 30 reference units/ml of mouse interferon there was a 30 to 200 times reduction in the production of infectious vesicular stomatitis virus (VSV); virus particle production, as measured by VSV particle associated virus RNA, virus protein, and virus transcriptase, was inhibited by, at most, six times. These results suggested that interferon-treated cells produce VSV particles with low infectivity and resemble the findings in interferon-treated cells infected with murine leukaemia viruses.
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PMID:Production of vesicular stomatitis virus with low infectivity by interferon-treated cells. 22 98

The in vitro transcription of viral specific DNA sequences in nuclei and chromatin isolated from mouse cells chronically infected with Moloney murine leukemia virus (Mo-MuLV) has been studied. The in vitro RNA synthesized by Escherichia coli RNA polymerase has been isolated by sulfhydryl affinity column following reaction in the presence of 5-mercuriuridine triphosphate. By comparison of the Crt curves of the in vitro RNA with that of 70S viral RNA, the content of viral sequences is found to be 1.3% in nuclei product and 0.24% in chromatin product which is lower than the 2.5% found in chromatin associated RNA. This latter value, however, is very close to the in vivo viral RNA content in pulse-labeled [3H]RNA of the infected cells. Unexpectedly, it is observed that over 20% of the chromatin associated RNA prelabeled in vivo with [5-3H]uridine is elongated and tagged with Hg atoms during RNA synthesis catalyzed by the exogenous E. coli RNA polymerase in the presence of Hg-UTP. The elongation reaction is dependent on the presence of all four nucleotide triphosphates and appears to be due to E. coli RNA polymerase per se. It is suggested that most of the viral specific sequences observed in the in vitro RNA products are very likely initiated and derived from the chromatin associated species. The implication of the present findings for in vitro RNA synthesis in nuclei and chromatin as related to regulation of gene expression is discussed.
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PMID:In vitro transcription of Moloney leukemia virus genes in infected cell nuclei and chromatin: elongation of chromatin associated ribonucleic acid by Escherichia coli ribonucleic acid polymerase. 32 7

The rational design of antitumor and antiviral agents must ultimately take advantage of biochemical differences between normal host cells and transformed cells. The initial experiments must be performed with subcellular or cellular model systems. For the studies with arabinosyl nucleosides we have chosen those enzyme systems, synthesizing DNA and RNA; being precursor analogues, the different arabinosyl nucleosides have been added in the triphosphate state to the different DNA- and RNA polymerase assays. 1-beta-D-Arabinofuranosylcytosine-5'-triphosphate has been found to inhibit the RNA-dependent DNA polymerases (isolated from oncogenic RNA viruses) 200-fold more sensitively than viral and cellular DNA-dependent DNA polymerases. Recent results, showing that RNA-leukemia-virus-related sequences are present in DNA of some human leukemia patients might support the assumption that the efficacy of this antimetabolite in the treatment of acute leukemia is due to its, at least relative selective inhibitory activity on reverse transcriptase. 9-beta-D-Arabinofuranosyladenine-5'-triphosphate is a strong inhibitor of cellular DNA polymerases with the cytological consequence of an inhibition of cell proliferation. The clinical benefit of the compound in treatment of tumors is dependent on their levels of adenosine deaminase. The triphosphate of this compound is a 100-fold more sensitive inhibitor of the herpesvirus DNA polymerase compared to the cellular replicative DNA polymerase. In addition the analogue, incorporated into herpesvirus DNA, acts as chain terminator. These effects are the biochemical basis for the highly selective antiherpesvirus activity of this antimetabolite. The anomer 9-alpha-D-arabinofuranosyladenine-5'-triphosphate only inhibits cellular replicative DNA polymerase and has no effect on herpesvirus DNA polymerase. Consequently this agent acts only cytostatically and not antivirally. Concerning 1-beta-D-arabinofuranosyluracil and 1-beta-D-arabinofuranosylthymine no pronounced antitumor or antiviral effect is known.
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PMID:Rational design of arabinosyl nucleosides as antitumor and antiviral agents. 61 2

Multiple forms of RNA polymerases (I, II and III) from murine leukemia L1210 cells are solubilized, purified and characterized. Heterogeneity of RNA polymerases I and III is revealed by chromatography on DEAE-Sephadex and Phosphocellulose (P-11). The properties of these forms such as peculiarities of transcription of native and denaturated DNA, metal ion dependence (Mg2+, Mn2+ and (NH4)2SO4) and alpha-amanitin sensitivity resemble those reported for other mammalian RNA polymerases. The level of RNA polymerase I of leukemia L1210 cells increase approximately ten-fold relative to its level in some organs of healthy mice.
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PMID:[RNA-polymerase of murine leukemia L1210 cells]. 62 42

Five cytotoxic Mannich bases (5-dimethylamino-1-substituted phenyl-1-penten-3-ones), three having antineoplastic activity, were evaluated for respiratory-inhibiting properties in rat liver mitochondria in the presence of four substrates: succinate, glutamate, 3-hydroxybutyrate, and palmitylcarnitine. Four compounds (Ib--Ie) showed significant inhibiting properties which, on occasion, were reversed partially by coenzyme Q10. Evaluation of the spectra of the mitochondrial cytochromes indicated that Ib--Ie blocked the electron transport chain prior to the sequence of cytochromes. Since inhibition occurred when different substrates were used, a common site of action for Ib--Ie is likely; competition of Ib--Ie with coenzyme Q10 probably occurs. Compounds Ia--Ie inhibited RNA polymerase from Swiss mouse kidney cells but were virtually bereft of activity versus RNA polymerase from L-1210 leukemia cells. Polarography of the Mannich bases and the related styryl ketones showed that antineoplastic activity was associated with higher half-wave potentials.
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PMID:Effect of antineoplastic and cytotoxic Mannich Bases derived from conjugated styryl ketones on mitochondrial respiration in rat liver cells. 71 88

The RNA polymerase activities from the nuclei of the spleen of uninfected and Rauscher murine leukemia virus-infected NIH Swiss mice were resolved by DEAE-cellulose column chromatography, and their properties were compared. The RNA polymerase activities from infected and uninfected spleens were the same with respect to column elution profiles, optimum requirements for various salts, ratios of activities with Mn2+ and Mg2+, sedimentation values, and response to most templates. With the exception of minor differences in activities with certain DNA templates, the significance of which is not clear, no qualitative differences in the enzymes from these two sources were found, but an increase in the specific activity of the alpha-amanitin sensitive enzyme, RNA polymerase II, was found in the leukemic spleen. These preliminary results suggest that there may be no novel RNA polymerase induced by Rauscher murine luekemia virus-infection, and they are in keeping with the interpretation that the viral DNA genome is transcribed by a host RNA polymerase.
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PMID:Deoxyribonucleic acid-dependent ribonucleic acid polymerases from spleen of uninfected and Rauscher murine leukemia virus-infected NIH Swiss mice.? 112 31

Friend murine leukemia virus induces splenic enlargement and an increase in RNA polymerase activity of spleen nuclei. Actinomycin D, administered at 60 mug/kg body weight/day prevents the development os splenomegaly and the elevation of polymerase activity following infection, but it has only a slight effect on the production of virus in spleen tissue. Thus, the alteration of RNA synthesis is not a result of virus proliferation, but instead may be a manifestation of leukemic erythropoiesis. Normal erythropoiesis, stimulated by erythropoietin administration, produces a similar but transient increase in RNA polymerase activity in spleen nuclei. Erythropoietin administered before, but not after, Friend virus infection results in an enhancement of RNA polymerase activity, as measured 9 days after inoculation. This effect is most simply explained by assuming that there is a common target cell pool for both erythropoietin and Friend virus, and that this pool becomes refractory to the influence of the hormone as a result of the leukemic process.
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PMID:Role of cellular RNA polymerases in virus-induced leukemogenesis. 114 21

The activity of DNA-dependent RNA polymerase A and B in isolated nuclei of spleens of mice infected with Rauscher leukemia virus was studied. A 3-fold increase in the activity of both RNA-polymerases in leukemic spleens was established. Study of the properties of RNA-polymerase B from nuclei of spleens of mice infected with Rauscher virus in comparison with the enzyme from normal tissue revealed the existence of some specific features in the enzyme from leukemic cells. The nature of the increased activity of RNA-polymerase B in leukemic cells is discussed.
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PMID:[Activity of DNA-dependent RNA polymerases A and B in spleen nuclei of mice infected with Rauscher leukemia virus]. 125 55

Reverse transcriptase template switching has been invoked to explain several aspects of retroviral replication and recombination, and has been reported in vitro for the Moloney murine leukemia virus (M-MuLV) reverse transcriptase. During in vitro cDNA synthesis, the avian myeloblastosis virus (AMV) reverse transcriptase can switch from one template to another in a homology-dependent and temperature-dependent manner. Chimeric cDNA molecules are generated within 30 min at high incubation temperatures, with an increasing efficiency from 42 degrees C to 50 degrees C. Such products are detectable only after much longer incubation times when primer extension reactions are carried out at lower temperatures (90 min at 37 degrees C).
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PMID:Temperature-dependent template switching during in vitro cDNA synthesis by the AMV-reverse transcriptase. 127 21

Bovine leukemia virus (BLV) is the etiologic agent of leukemia in cattle and is believed to cause decreases in milk productivity, fertility, and life span in infected cows. BLV is a type C retrovirus in the Oncovirinae subfamily. It is most closely related to human T-cell lymphoma/leukemia virus type I (HTLV-I) and type II (HTLV-II). Since the polymerase chain reaction (PCR) provides rapid and efficient amplification of DNA sequences, primers were designed to amplify regions of the polymerase (pol) and pX genes specific for BLV targets. These sets of primers consistently amplified as few as 10 copies of BLV DNA contained in a plasmid in the background of 1 microgram of either human or bovine chromosomal DNA. In addition, no amplification products were detected from cell lines infected with HTLV-I, HTLV-II, or human immunodeficiency virus type 1 or 2 by the BLV PCR systems. Samples of peripheral blood mononuclear cells from 18 cows, previously determined to be serologically positive or negative, were correctly identified in a blind study as containing proviral DNA by use of the BLV primers and probes. Cloning and sequencing of amplified products revealed finite sequence variations among a previously cloned BLV isolate, the wild-type virus, and the published genome. Reverse transcriptase-directed PCR with the primers for both BLV pol and BLV pX was performed on plasma from a BLV-infected cow and detected in vivo BLV RNA expression. In summary, we have developed a specific and sensitive assay using PCR for the detection and identification of BLV infections; this assay can now be applied to clinical and basic research questions in veterinary medicine.
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PMID:Amplification and analysis of specific DNA and RNA sequences of bovine leukemia virus from infected cows by polymerase chain reaction. 137 Aug 47


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