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)

The new antiviral substance phosphonoformate (PFA) has been tested in a cell-free system for its effect on reverse transcriptases from an avian retrovirus (avian myeloblastosis virus, AMV) and from mammalian retroviruses (Rauscher leukaemia virus, RMuLV; bovine leukaemia virus; baboon endogenous virus; simian sarcoma virus; visna virus). The observed inhibitory effect of PFA has been compared with that of a structurally related substance, phosphonoacetate (PAA). Phosphonoformate, at a concentration of 100 microM, reduced the activities of all the above mentioned polymerases by 90% when (rA)n.(dT)10 was used as a template/primer. The dose-response curves for AMV and RMuLV polymerases primed with (rA)n.(dT)10 showed PFA to be a 1000-fold more active than PAA; the RMuLV polymerase activity was reduced to 50% after incubation with 0.7 microM-PFA and 0.7 mM-PAA, respectively. There was no difference in PFA inhibition of virus-associated and purified reverse transcriptase activity. Results with various synthetic templates showed that both the RNA- and the DNA-dependent polymerase activities of reverse transcriptase were inhibited by PFA. The endogenous polymerase activity of AMV was inhibited to 50% at 100 microM-PFA, while PAA had no effect. The PFA inhibition was dependent on whether Mg2+ or Mn2+ was used as divalent cation in the assay. Phosphonoformate arrested DNA synthesis immediately after being added to the assay system. The mechanism of inhibition of the AMV polymerase was non-competitive with respect to substrate and template and the apparent inhibition constants were 16 microM and 9 microM, respectively.
J Gen Virol 1979 Nov
PMID:Phosphonoformate inhibits reverse transcriptase. 9 44

The RNA components of two C-type RNA viruses, avian myeloblastosis virus and Friend leukaemia virus, have been isolated by treatment of the viruses with 6 M-guanidine-HCl and precipitation with ethanol. The virus proteins were recovered by lyophilization of the guanidine-HCl-ethanol supernatant after thorough dialysis against 0.5 mM-dithiothreitol. This simple method yielded RNA of similar quality to the phenol and sodium dodecyl sulphate (SDS) extraction methods, and the same amount of 60-70S RNA, although a fraction of the smaller (4S) species remained in the protein fraction. The sedimentation patterns of heat-denatured RNA extracted by either method were similar. Electrophoretic analyses of the extracted proteins in polyacrylamide gel gradients containing SDS gave patterns that were very similar to those obtained by direct analysis of SDS disrupted viruses.
J Gen Virol 1978 Jul
PMID:The use of guanidine-HCl for the isolation of both RNA and protein from RNA tumour viruses. 21 Nov 81

Aspartic proteinases from human immunodeficiency virus type 1 (HIV-1) and avian myeloblastosis virus (AMV) were found to interfere with microtubule assembly. Preincubation of the proteinases with purified brain microtubule proteins (tubulin and microtubule-associated proteins) at low ionic strength (pH 6.8), completely inhibited microtubule assembly. Analysis of microtubule proteins after incubation with proteinase showed no effect on tubulin but extensive cleavage of the microtubule-associated proteins 1 and 2 was observed. The digestion by the two proteinases differed. In the presence of HIV-1 proteinase, a fragment with an Mr of approximately 300, appeared, as well as at least three other new fragments, with Mr values of 188,000, 124,000 and 73,000. In the presence of AMV proteinase, the microtubule-associated proteins were extensively digested to many small fragments. The extending microtubule-associated proteins normally seen by electron microscopy on the microtubule surface disappeared after treatment with AMV proteinase. Our results show that retroviral proteinases are not restricted to cleavage of viral polyproteins in vitro. It is suggested that proteolysis of microtubular proteins by viral proteinases is an important step in viral pathogenicity and that it may be part of a mechanism causing degenerative effects in infected cells.
J Gen Virol 1990 Sep
PMID:Proteolytic cleavage of microtubule-associated proteins by retroviral proteinases. 221 89

An antiserum made against a synthetic peptide from an internal region of the predicted amino acid sequence of the avian myeloblastosis virus (AMV) transforming v-myb(AMV) gene identified two products, p46v-myb(AMV) and p32v-myb(AMV), which were localized in the nucleus of AMV-transformed myeloblasts. We propose that these proteins are the in vivo products of the v-myb(AMV) gene and thus the transforming protein(s) of AMV.
J Gen Virol 1985 Dec
PMID:Detection and localization of the v-myb(AMV) gene products of avian myeloblastosis virus by a synthetic peptide antiserum. 299 19

The avian RNA tumour virus structural protein p12 was purified from avian myeloblastosis virus (AMV) by nucleic acid affinity chromatography to apparent homogeneity as judged from SDS--polyacrylamide gel electrophoresis. A filter binding assay was used for the identification of p12. High concentrations of p12 precipitated nucleic acids out of solution in the absence of MgCl2. Binding of p12 to single-stranded nucleic acids protected them from digestion with nucleases and resulted in a hyperchromic effect. These phenomena were reversible in the presence of salt. The affinity of p12 to nucleic acids was determined by competing for the binding of p12 to denatured radioactive DNA by various other nuclei acids. It was found that p12 bound preferentially to single-stranded nucleic acids and showed a higher affinity to poly(rI) than to poly(rC) and poly(rA). Purified RNA-dependent DNA polymerase activity from AMV was stimulated up to sixfold by p12, depending on the template. Solubilization of RNA in RNA--DNA hybrids by RNase H was inhibited in the presence of p12.
J Gen Virol 1981 Aug
PMID:Properties of the avian viral protein p12. 616 96

A three-step sandwich enzyme-linked immunosorbent assay was developed for the detection of avian oncovirus group-specific (gs) antigens. The assay procedure was to coat the wells of microtitre plates with hamster anti-gs IgG, react with crude or purified antigen and finally with hamster anti-gs IgG linked to horseradish peroxidase. The sensitivity was 8 picograms (pg) of input avian myeloblastosis virus (AMV) protein, with negligible background. As the ELISA takes less than 2 h to perform, large-scale screening for infected birds is feasible. A blocking assay was also developed for detecting anti-gs antibodies by adding unlabelled antiserrum after the antigen step.
J Gen Virol 1980 Apr
PMID:Detection of avian oncovirus group-specific antigens by the enzyme-linked immunosorbent assay. 624 72

Avian myeloblastosis virus consists of a mixture of a defective leukaemia virus and several non-defective associated avian leukosis viruses. The genomes of two of the associated avian leukosis viruses were examined in this study and were chosen because one of them, MAV-2(N), induces predominantly nephroblastoma, while the other, MAV-2(O), induces predominantly osteopetrosis. Competitive hybridization studies employing labelled virion RNA and DNA from normal and malignant tissue failed to demonstrate a difference the genomes. However, examination of ribonuclease T1-resistant oligonucleotide maps revealed that MAV-2(N) RNA had five oligonucleotide fragments which were not present in the MAV-2(O) genome. Poly(A) selection of the oligonucleotides at the 3' end of the genome showed that the fragments unique to MAV-2(N) were not present at this end of the genome. These results suggest that two viruses differing in oncogenic manifestation also differ in genome composition.
J Gen Virol 1982 May
PMID:Avian nephroblastoma virus MAV-2(N) and avian osteopetrosis virus MAV-2(O) are genetically distinct. 628 66

Peripheral blood lymphocytes of chickens bearing tumours induced by avian sarcoma virus can be specifically stimulated to divide by the crude culture fluids of virus-infected cells. In this communication, we show that relevant antigenic activity apparently resides in each of the internal virus proteins p15 and p27. The ability of infectious culture fluids to be mitogenic for sensitized lymphocytes is greatly reduced following treatment with antibodies specific for either total avian myeloblastosis virus (AMV) protein or for p27.
J Gen Virol 1982 Jun
PMID:Immune stimulation of sensitized chicken lymphocytes by avian retrovirus proteins. 628 58

Inhibitors of bacterial DNA gyrase and eukaryotic DNA topoisomerase (novobiocin and nalidixic acid) were investigated with respect to their effect on the activity of RNA-dependent DNA polymerases from murine and avian retroviruses. Purified RNA-dependent DNA polymerase from AKR virus was inhibited more than 90% by 0.3 mg/ml and almost completely by 1 mg/ml of the drugs when poly(A) X oligo(dT)12-18 was used as a template-primer. In contrast to the enzyme from AKR virus, purified enzyme from avian myeloblastosis virus was less sensitive, i.e. nearly 50% activity remained even in the presence of 1 mg/ml of the drugs with the same template-primer. RNA-dependent DNA polymerase activity in AKR virus particles was inhibited, but was resistant to low concentrations of the drugs. The inhibition was not due to specific interaction between drugs and the template-primer or labelled precursor, since RNA-dependent DNA polymerase was inhibited by the drugs with activated calf thymus DNA or poly(C) X oligo(dG)12-18 as the template. Endogenous DNA synthesis by AKR virus particles was inhibited by novobiocin to the same extent.
J Gen Virol 1983 Oct
PMID:Inhibition of retrovirus RNA-dependent DNA polymerase by novobiocin and nalidixic acid. 631 59

Recent studies have revealed that 'human retrovirus-5' sequences found in human samples belong to a rabbit endogenous retrovirus family named RERV-H. A part of the gag-pro region of the RERV-H genome was amplified by PCR from DNA in human samples and several forms of RERV-H protease were expressed in bacteria. The RERV-H protease was able to cleave itself from a precursor protein and was also able to cleave the RERV-H Gag polyprotein precursor in vitro whereas a form of the protease with a mutation engineered into the active site was inactive. Potential N- and C-terminal autocleavage sites were characterized. The RERV-H protease was sensitive to pepstatin A, showing it to be an aspartic protease. Moreover, it was strongly inhibited by PYVPheStaAMT, a pseudopeptide inhibitor specific for Mason-Pfizer monkey virus and avian myeloblastosis-associated virus. A structural model of the RERV-H protease was constructed that, together with the activity data, confirms that this is a retroviral aspartic protease.
J Gen Virol 2003 Jan
PMID:Rabbit endogenous retrovirus-H encodes a functional protease. 1253 18


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