Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A particle fraction with a density of 1.15-1.19 g/cm3 was isolated from the cytoplasm of a human cell line established in culture from the bone marrow of an untreated patient with polycythemia vera. Electron micrographs of cross sections of cells and cell homogenates revealed virus-like particles on which DNA could be synthesized. An RNA-dependent DNA polymerase, isolated from the particles, preferred poly(rA)-oligo(dT) over poly(dA)-oligo(dT) and was able to polymerize deoxyguanosine monophosphate in a reaction stimulated by poly(rC)-oligo(dG).
J Natl Cancer Inst 1975 Sep
PMID:Particle-associated RNA dependent DNA polymerase and high-molecular-weight RNA in a human cell line derived from polycythemia vera bone marrow. 5 Oct 88

Extracellular murine leukemia virus (MLV) reverse transcriptase activity was decreased by interferon treatment in four interferon-sensitive mouse cell lines which were chronic MLV producers. In three cell lines which were relatively insensitive to interferon, extracellular enzyme activity remained unchanged by interferon treatment. The concentrations of interferon used had no effect on DNA synthesis or cell replication of AKR,C+ cells which were chronic producers of AKR-MLV. In AKR,C+ cultures interferon treatment also had no effect on the level of intracellular viral reverse transcriptase activity in spite of an inhibition of extracellular enzyme activity. Treatment of AKRC+ cultures with interferon for 9 days inhibited extracellular viral reverse transcriptase levels throughout the period of treatment; however, the intracellular enzyme activity remained unchanged, and concentrations of viral p30 (gs) antigen were increased in the interferon-treated cells. When the cells were washed to remove interferon, however, virus production rapidly rose and intracellular p30 antigen fell to the levels of untreated AKR,C+ cells. These and previously reported results suggested that in interferon-treated AKR,C+ cells virus production is inhibited at a late step in the MLV replication cycle, either directly or through the inhibition of the production of a protein required for virus assembly.
J Virol 1975 Sep
PMID:Interferon-directed inhibition of chronic murine leukemia virus production in cell cultures: lack of effect on intracellular viral markers. 5 Nov

The DNA product of the endogenous reverse transcriptase reaction of Gibbon ape lymphoma virus has been analyzed and characterized. Data show that in simultaneous detection assays in which the type and/or concentration of divalent cation is varied the best yield of rapidly-sedimenting DNA was obtained from reactions containing 1.5 mM Mn2+. This yield is ten-fold better than the yield observed at the optimal Mg2+ concentration (5.0mM). Evidence is presented to show that DNA synthesized at the optimal concentration of either of these cations consists of large pieces varying in size from 4 to 12S. This DNA hybridizes efficiently to homologous viral RNA (greater than 60 percent annealing) and protects at least two-thirds of GALV 70S [32P]RNA from ribonuclease digestion. The hybrids formed with homologous viral RNA are stable as evidenced by their thermal elution patterns from hydroxylapatite columns. In contrast, DNA synthesized in reactions in which the concentration of Mn2+ or Mg2+ was greater than optimal was predominantly 4S or smaller in size and displayed a low level of hybridization (less than 10 percent) to homologous viral RNA.
Biochim Biophys Acta 1975 Sep 12
PMID:The endogenous reverse transcriptase activity of Gibbon ape lymphoma virus: characterization of the DNA product. 5 76

A high-molecular-weight RNA encapsulated with an RNA-instructed DNA polymerase in particles possessing the density characteristic of the RNA tumor viruses has been detected in 13 out of 14 human malignant melanomas. The [3H]DNA synthesized by these particles in an endogenous reaction hybridizes to RNA extracted from the human melanoma particulate structures, but not to RNA from normal skin. Similar particles containing RNA and enzyme have been found in basal cell and squamous cell carcinomas of the skin. The RNA of the melanoma particles is easily distinguishable by hybridization from the RNAs found in the particles of the basal and squamous cell carcinomas.
Proc Natl Acad Sci U S A 1975 Sep
PMID:Oncornavirus-like particles in human skin cancers. 5 74

Equine infectious anemia virus (EIAV) has a density of 1.154 g/cm3 in sucrose a high-molecular-weight RNA similar in size to Rauscher murine leukemia virus, and an internal virion reverse transcriptase that utilizes the synthetic RNA template poly(rA) but not the synthetic DNA template poly(dA), both with (dT)12 as primer. Although capable of utilizing manganese at low concentrations (approximately 0.1 mM), EIAV reverse transcriptase showed highest activity in the presence of 9 mM magnesium. The major protein of EIAV has a slightly lower molecular weight than the comparable protein of type C viruses and co-electrophoresed with 125I-labeled p25 of Mason-Pfizer monkey virus. A reference horse serum with antibodies to the major EIAV protein reacted only with EIAV and not with other type C or non-type C retraviruses. Reciprocally, a broadly reactive serum to type C virus p30s and specific sera to a variety of non-type C retraviruses did not react with EIAV. We recommend the inclusion of EIAV in the family Retraviridae.
J Virol 1976 Sep
PMID:Equine infectious anemia virus: evidence favoring classification as a retravirus. 6 Dec 83

Assay of particulate reverse transcriptase activity in the sera from feral mice naturally infected with type C virus provides a sensitive and rapid procedure for the determination of in vivo virus infection. The results compare well with assays for infectious virus and with complement fixation or competitive radio-immunoassays for the p30 internal antigen of the virus.
J Virol 1976 Sep
PMID:Assay for type C virus in mouse sera based on particulate reverse transcriptase activity. 6 Dec 84

Activity of RNA-dependent DNA polymerase (RDDP) from avian myeloblastosis virus (AMV), either in purified form or in virus lysates, was increased by phosphorylation. Stability of RDDP in lysates buffered with phosphate was much greater (no loss of activity in 48 hours at 4 degrees) than that in lysates buffered with Tris-Cl (76% loss). Activity lost in the Tris-buffered extracts was completely restored by phosphorylation. The findings suggested that AMV RDDP activity is influenced by the degree of phosphorylation of the enzyme or enzyme-associated proteins and that this chemical modification is mediated by protein phosphokinase and phosphoprotein phosphatase present in crude extracts of purified AMV. Application of these results provided the basis of procedures whereby RDDP can be recovered in significantly higher yield and purity than formerly.
Nucleic Acids Res 1976 Sep
PMID:Influence of phosphate on activity and stability of reverse transcriptase from avian myeloblastosis virus. 6 81

The properties of an RNA-dependent DNA polymerase (an RNA-dependent DNA nucleotidyltransferase), which occurs ubiquitously in the allantoic fluid of uninfected, leukosis-virus-free eggs, are described. It is shown that the enzyme can synthesize faithful transcripts from natural RNA (globin mRNA). By biochemical and immunological methods, the enzyme can be clearly distinguished from the reverse transcriptases of the known chicken RNA tumor viruses and therefore seems to be a member of a so far unknown class of chicken polymerases.
Proc Natl Acad Sci U S A 1976 Sep
PMID:An RNA-dependent DNA polymerase, different from the known viral reverse transcriptases, in the chicken system. 6 87

Adriamycin inhibited the endogenous RNA-, poly (A)-d(T)12-, and calf thymus DNA-catalyzed reaction of reverse transcriptase from AKR mouse murine leukemia virus (AKR-MLV). This inhibition was found at the reaction levels of endogenous RNA-directed and subsequent DNA-directed DNA synthesis. Although adriamycin and actinomycin D significantly reduced the growth of AKR mouse cells (K3b), the treatment with adriamycin could bot inhibit the AKR-MLV production in these cells. Actinomycin D inhibited AKR-MLV production completely in the same experimental condition. In adriamycin-resistant K3b/Am cells, which were isolated by intermittent treatment of K3b cells with adriamycin, persistence of AKR-MLV was demonstrated. K3b/Am cells showed some altered characteristics such as reduced growth rate and tumorigenicity.
Cancer Res 1976 Sep
PMID:Effects of adriamycin on the reverse transcriptase and the production of murine leukemia virus. 6 7

Northern poke lymphosarcoma DNA polymerase was partially purified from particulate fractions banding at 1.15 to 1.16 g/ml from homogenates prepared from frozen necropsies of tumor-bearing pike. The enzyme behaves as a typical reverse transcriptase, in that it prefers ribotemplates to deoxytemplates. The isoelectric point (pl 5.5) is similar to that of avian myeloblastosis virus polymerase. The pike enzyme elutes from a phosphocellulose column at 0.22 M potassium phosphate, the same as avian myeloblastosis virus DNA polymerase. The enzyme activity is inhibited by pyran, a specific inhibitor of viral DNA polymerases. The most striking difference between the pike lymphoma polymerase and the other viral DNA polymerases tested is the low maximum temperature of 20 degrees, compared to 30 degrees for Rauscher leukemia virus polymerase and 38 degrees for avian myeloblastosis virus and Rous sarcoma virus.
Cancer Res 1977 Sep
PMID:Presence of DNA polymerase in lymphosarcoma in northern pike (Esox lucius). 6 92


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