Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0679427 (myeloblastosis)
 982 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

2',3'-dideoxy-2',3'-dehydrothymidine 5'-triphosphate (dddTTP) shows termination substrate properties in the DNA synthesis catalyzed by E. coli DNA polymerase I KF, rat liver DNA polymerase beta, reverse transcriptases of avian myeloblastosis virus and Raus sarcoma virus and calf thymus terminal deoxynucleotidyl transferase. This implies that the mononucleotide residue of dddTTP incorporates into 3'-termini of newly synthesized DNA chains. However, dddTTP has no influence on the DNA synthesis catalyzed by calf thymus DNA polymerase alpha. In the case of some DNA polymerases dddTTP was one order of magnitude more effective in comparison with the other known termination substrates.
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PMID:Properties of 2',3'-dideoxy-2',3'-dehydrothymidine 5'-triphosphate in terminating DNA synthesis catalyzed by several different DNA polymerases. 243 82

DNA-protein interactions involving enhancer and promoter sequences within the U3 regions of several avian retroviral long terminal repeats (LTRs) were studied by DNase I footprinting. The rat CCAAT/enhancer-binding protein, C/EBP, bound to all four viral LTRs examined. The Rous sarcoma virus binding site corresponded closely to the 5' limit of the LTR enhancer; nucleotides -225 to -188 were protected as a pair of adjacent binding domains. The Fujinami sarcoma virus LTR bound C/EBP at a single site at nucleotides -213 to -195. C/EBP also bound to the promoter region of the enhancerless Rous-associated virus-0 LTR at nucleotides -77 to -57. The avian myeloblastosis virus LTR bound C/EBP at three sites: nucleotides -262 to -246, -154 to -134, and -55 to -39. We have previously observed binding of C/EBP to an enhancer in the gag gene of avian retroviruses. A heat-treated nuclear extract from chicken liver bound to all of the same retroviral sequences as did C/EBP. Alignment of the avian retroviral binding sequences with the published binding sites for C/EBP in two CCAAT boxes and in the simian virus 40, polyoma, and murine sarcoma virus enhancers suggested TTGNNGCTAATG as a consensus sequence for binding of C/EBP. When two bases of this consensus sequence were altered by site-specific mutagenesis of the Rous sarcoma virus LTR, binding of the heat-stable chicken protein was eliminated.
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PMID:Avian retroviral long terminal repeats bind CCAAT/enhancer-binding protein. 272 92

3'-Azido-2',3'-dideoxythymidine (az-T) inhibited effectively the reproduction of some retroviruses; among these viruses were the four serological subgroups of sarcoma Raus virus in chicken embryo, avian myeloblastosis virus and erythroblastosis virus in chicken. This inhibition was specific towards retroviruses and practically was not observed in the case of infections DNA- and RNA-genome model viruses of vaccinia and influenza, at whose reproduction reverse transcriptase is not involved. Three other 3'-modified nucleosides did not block the above-listed retroviruses. For chickens, az-T showed low toxicity. The molecular mechanisms of the action of az-T are discussed.
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PMID:[The effect of 3'-azido-2',3'-dideoxythymidine on experimental viral infections]. 282 79

Nine human hybridoma cell lines were established from a fusion of axillary lymph node lymphocytes of a patient with breast ductal carcinoma with a human lymphoblastoid cell line. The human hybridoma nature of the fusion products was confirmed by chromosomal analysis and HLA typing. The hybridomas are stable over a year of growth, and can be frozen, thawed and regrown. The carcinoma cells of the patient harbor mouse mammary tumor virus (MuMTV) cross-reacting antigens. The patient's serum and the purified monoclonal antibodies reacted with MuMTV polypeptides. Radioimmunoprecipitation studies using labeled MuMTV confirmed the binding of the patient's serum to the viral proteins. None of the control immunoglobulins reacted with the virus. No binding of the hybridoma immunoglobulins was observed with two other retroviruses (avian myeloblastosis virus and simian sarcoma virus). The ligand binding characteristics of the monoclonal antibodies suggest binding to epitopes on the various structural virus polypeptides. These monoclonal antibodies may serve as a probe to analyze the MuMTV-human breast carcinoma relationship.
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PMID:Human monoclonal antibodies derived from lymph nodes of a patient with breast carcinoma react with MuMTV polypeptides. 302

The proteolytic processing of the gag precursor polypeptide pr65gag of simian sarcoma-associated virus (SSAV) has been studied in vivo and in vitro. In SSAV-infected cells (i.e., in vivo) proteins of 52 and 38 kDa and the viral protein p30 could be immunoprecipitated with anti-p30 serum. This cleavage pattern is only in part imitated by in vitro cleavage of the isolated pr65gag with avian myeloblastosis virus (AMV) protease p15. However, in vitro incubation of isolated pr65gag with detergent-disrupted SSAV particles generated products identical in size to those found in vivo, i.e., proteins of 52 and 38 kDa and p30. The extent of cleavage is dependent on the concentration of the disrupted virions added to the incubation mixture. Studies with protease inhibitors suggest that the SSAV enzyme is a serine-type protease like that of other mammalian retroviruses and unlike the protease of avian viruses. The SSAV protease activity eluted from a molecular sieve column in a range of about 10-15 kDa reflecting the molecular weight of the murine leukemia virus (MuLV) protease (Mr = 13.5K). Thus, it appears that there is a close similarity between the proteolytic enzymes present in different mammalian retroviruses such as MuLV and SSAV.
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PMID:Characterization of a virus-specific proteolytic activity processing the gag precursor of the simian sarcoma-associated virus. 302 76

Monospecific antiserum prepared against the isolated deoxyribonucleic acid (DNA) polymerase of avian myeloblastosis virus (AMV) neutralized the endogenous ribonucleic acid-instructed DNA polymerase activity of detergent-disrupted virus. The viral polymerase was serologically unrelated to the seven major structural polypeptides of AMV. Furthermore, the viral enzyme was distinguished from normal cellular DNA polymerases by serological criteria; thus, antiserum against the viral enzyme neutralized its homologous antigen but not normal cellular DNA polymerases. Neutralization by antibody of viral DNA polymerase activity was observed with all avian leukemia-sarcoma viruses tested, irrespective of viral antigenic subtype. The DNA polymerase activity of avian reticuloendotheliosis virus, and of a variety of mammalian oncornaviruses, was not neutralized by antisera against the AMV polymerase. Immunological analysis of the RSValpha(O) mutant, which is deficient in DNA polymerase activity, shows this mutant to lack demonstrable polymerase antigen. Viral polymerase was identified by immunofluorescence as a cytoplasmic constituent in virus-producing chicken cells; polymerase antigen was not detected in uninfected (gs(-)) chicken cells.
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PMID:Serological analysis of the deoxyribonucleic acid polymerase of avian oncornaviruses. II. Comparison of avian deoxyribonucleic acid polymerases. 411 66

Antibodies against a large and a small DNA polymerase isolated from chicken embryos and against avian myeloblastosis virus DNA polymerase were used to study the serological relationships of the DNA polymerase activities of three avian systems with RNA and a DNA polymerase-avian leukosis-sarcoma viruses, reticuloendotheliosis viruses, and a fraction from uninfected chicken cells. The DNA polymerase activity of disrupted virions of all avian leukosis-sarcoma viruses tested was neutralized to the same extent by antibody against avian myeloblastosis virus DNA polymerase and was not neutralized by the antibodies against chicken cellular DNA polymerases. The viruses tested included induced leukosis viruses and Rous-associated virus-O. The DNA polymerase activity of disrupted virions of all of the reticuloendotheliosis viruses was not neutralized by any of the antibodies. The chicken endogenous RNA-directed DNA polymerase activity was neutralized partially or completely, in different experiments, by antibody against the small DNA polymerase isolated from chicken embryos, but was not neutralized by the other two antibodies.
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PMID:Lack of serological relationship among DNA polymerases of avian leukosis-sarcoma viruses, reticuloendotheliosis viruses, and chicken cells. 412 28

Guinea pigs immunized intracerebrally with avian myeloblastosis virus (AMV) produced antiserum which reacted with intact virus particles in complement fixation. The antigen in question appeared to be located on the surface of the virion and could be distinguished from the type-specific virus envelope and the group-specific internal antigens of chicken leukosis-sarcoma viruses (ChiLSV). The material could be isolated by sequential treatments of AMV with bromelin, Tween 20, and freeze-thawing, and could be purified by differential centrifugation. Electron microscopy analysis indicated the presence of a component resembling the outer membrane of the particle. The antigenic determinant was designated virus membrane antigen (Vm). Further analyses revealed the presence of protein, lipid, and carbohydrate in a material having a molecular weight of about 6,000 as determined by sodium dodecyl sulfate gel electrophoresis. Serological studies suggested that the outer membranes of AMV and other ChiLSV are represented mainly by host cellular material.
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PMID:Outer membrane of avian myeloblastosis virus. 412 85

Ribonuclease H (RNA.DNA-hybrid ribonucleotidohydrolase, EC 3.1.4.34) has been reported to copurify with reverse transcriptase (RNA directed DNA polymerase) of RNA tumor viruses. In addition, viral specific ribonuclease H and reverse transcriptase of avian type-C viruses are thought to be part of the same polypeptide. In this report we show that a fraction of the ribonuclease H activity from Rauscher murine leukemia and Kirsten murine sarcoma viruses was separated from reverse transcriptase by anion exchange chromatography while the remaining portion co-purified with the viral polymerase. The amount of this co-purified nuclease activity was about 4- to 8-fold lower than the activity found in avian myeloblastosis virus (with respect to the ratio of ribonuclease H to reverse transcriptase) and this nuclease activity can only be detected by using labeled substrate of high specific radioactivity. However, a complete separation of ribonuclease H activity from reverse transcriptase was obtained by purifying core structures of the virus by sucrose density gradient centrifugation. While reverse transcriptase was present in the cores, there was no detectable ribonuclease H. Furthermore, a specific antibody against Rauscher leukemia virus reverse transcriptase did not inhibit any virion associated ribonuclease H activity. Our results suggest that in these virions these two enzyme activities reside in two separate molecules and probably in two different compartments of the virus. These findings emphasize a basic difference between the avian and murine type-C virus DNA polymerases.
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PMID:Separation of ribonuclease H and RNA directed DNA polymerase (reverse transcriptase) of murine type-C RNA tumor viruses. 413 16

Oncornavirus 60 to 70S ribonucleic acids (RNA), such as those from avian myeloblastosis virus, Schmidt-Ruppin virus, or mouse sarcoma-mouse leukemia viruses, isolated by conventional techniques, contain 4S transferlike RNA molecules that are released upon dissociation of the 60 to 70S RNA with heat. The 4S RNA represents 2.5 to 3.0% of the RNA in the 65S aggregate or 4 to 5 molecules per molecule of 35S RNA formed.
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PMID:Association of 4S ribonucleic acid with oncornavirus ribonucleic acids. 432 70


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