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)

Cells infected by Rous-associated virus 61 (RAV-61) contained a precursor-like protein, pr90, that was specifically precipitated by antiserum directed against envelope glycoproteins, gp85 and gp35. Tryptic peptide mapping showed that pr90 contained tryptic sequences of both gp85 and gp35. Pactamycin mapping experiments indicated that the two glycoproteins are translated from the env-mRNA in the order (5') gp85--gp35. The pactamycin mapping experiments also indicated a translational order of p10--(p27, p12)--p15 for the gag proteins; this agreement with the order previously reported from tryptic mapping studies on precursor pr76 of avian myeloblastosis virus implied that the stoichiometry of the core proteins was unchanged when virions were assembled in the presence of pactamycin. The reverse transcriptase proteins, unlike those of the env and gag genes, fell on the right side of the pactamycin map. This result is in accord with the idea that most, if not all, of the reverse transcriptase protein is translated by read-through of the gag(pol) message rather than by translation of a hypothetical pol-mRNA devoted solely to synthesis of that protein.
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PMID:Proteins of Rous-associated virus 61, an avian retrovirus: common precursor for glycoproteins gp85 and gp35 and use of pactamycin to map translational order of proteins in the gag, pol, and env genes. 7 10

A procedure was established whereby most of the major viral proteins were isolated to apparent homogeneity in biologically and immunologically active forms from a single batch of avian sarcoma virus QV2. For the initial step of purification, gently disrupted virions were fractionated by CsCl centrifugation into envelope proteins, RNA-dependent DNA polymerase, and viral core proteins. Further purification of envelope glycoproteins and DNA polymerase was performed by affinity chromatography on agarose columns cross-linked with plant lectins and poly(C), respectively. On the other hand, core proteins were fractionated by a combination of gel filtration and ion-exchange column chromatography into components p27, p19, and p15. The core protein p15 thus isolated retained proteolytic activity even after storage for 6 months. The present study also demonstrated that QV2 p19 is structurally altered from the corresponding protein of avian myeloblastosis virus (AMV), a reference avian leukosis-sarcoma virus having a well-characterized polypeptide composition.
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PMID:Purification of viral proteins from avian sarcoma virus QV2. 11 57

After microinjection of Xenopus laevis oocytes with RNA from avian myeloblastosis virus, viral structural proteins p27, p19, p15, and p12 are formed by a sequence of posttranslational cleavages of a high-molecular-weight precursor polypeptide. The 60-70S RNA aggregate or its 30-40S RNA subunits obtained by heat or formamide treatment possess the same ability to serve as template in X. laevis oocytes. The processing pattern of virus-specific precursor polypeptides is the same in X. laevis oocytes as in chick embryo fibroblasts infected with avian myeloblastosis virus, but the processing takes place at a much slower rate.
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PMID:Frog oocytes synthesize and completely process the precursor polypeptide to virion structural proteins after microinjection of avian myeloblastosis virus RNA. 19 76

The isoelectric focusing technique in the pH gradients was used for a preparative isolation of proteins from Rous sarcoma virus and avian myeloblastosis virus. The purified major gs protein, p27 (pI = 9.1) and the gP86 (pI = 5.3) were obtained after disruption of virus with 1% non-ionogenic detergent in the presence of 6M urea. The p10, p15, and p19 were present in the same range of pH (pI = 6.8). A strongly basic protein, immunologically active, presumably the p12, was found in the alkaline region of the pH gradient 10.8. These proteins fully retained their immunological activity. On the other hand, in the acidic region of the pH gradient between pH 4 and 5, strong precipitates were regularly found. These precipitates were complexes which were formed by interaction of the acid components of ampholines with the viral proteins during isoelectric focusing. Almost all viral proteins were present, differing only in quantity. The complexes were stabile in 1% non-inogenic detergent and 6M urea. They were dissociated with 1% SDS and 5M urea, and had no immunological activity. The methods of virus disruption and possibilities of formation of the ampholine-viral protein complexes are discussed.
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PMID:Fractionation of proteins from Rous sarcoma virus and avian myeloblastosis virus by isoelectric focusing. 21 31

Two protein kinase activities were fractionated from purified virions of avian myeloblastosis virus. Distinguishing characteristics of these two protein kinases included: (i) their binding properties during purification by ion-exchange chromatography; (ii) their estimated molecular weights; and (iii) their phosphoacceptor protein specificities. The protein kinase that bound to the anion exchanger DEAE-cellulose (pH 7.2) had an estimated molecular weight of 60,000 to 64,000 and preferred basic phosphoacceptor proteins. The protein kinase that bound to the cation exchanger phosphocellulose (pH 7.2) had an estimated molecular weight of 42,000 to 46,000 and preferred acidic phosphoacceptor proteins. The protein kinase preferring basic phosphoacceptor proteins was further purified and characterized. Optimal transfer of phosphate catalyzed by this enzyme required a divalent metal ion, a sulfhydryl-reducing agent, and ATP as phosphate donor. GTP was not an effective phosphate donor at concentrations comparable to ATP; and the cyclic nucleotides cyclic AMP and cyclic GMP neither stimulated nor inhibited protein phosphorylation by the protein kinase. The specificity of the protein kinase for basic phosphoacceptor proteins extended to proteins from avian myeloblastosis virus, in that the neutral to basic virion proteins p12, p19, and p27 served as phosphate acceptors. In addition, the protein kinase also appeared to phosphorylate itself. The role(s) of this virion-associated protein kinase is discussed.
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PMID:Fractionation of two protein kinases from avian myeloblastosis virus and characterization of the protein kinase activity preferring basic phosphoacceptor proteins. 22 78

An antigen detected by complement fixation with polyclonal antibody to avian myeloblastosis virus (AMV) antigen p27, appears in the livers of chickens inoculated with avian erythroblastosis virus (AEV). It can be demonstrated at the 30,000 dalton (30K) molecular weight level by Western immunoblotting of electropherograms of AEV infected liver extracts. The 30K protein reacted strongly with this polyclonal antibody but only weakly with a monoclonal antibody to the same viral antigen and possible explanations for this have been suggested. Both antibodies also appeared to react with other than viral components in the preparations of AMV used. As this apparent non-specific attachment of highly specific antibody may have as its explanation the failure of the gelatin to prevent nonimmunologically determined binding of the immunoglobulin; other blocking agents should be investigated.
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PMID:Immunoblotting with polyclonal and monoclonal antibody to avian myeloblastosis protein p27: studies of liver proteins in chickens with erythroblastosis. 283 98

Hybridoma cell lines secreting monoclonal antibody (MCA) to avian leukosis virus (ALV) structural proteins p27 and p19 have been established. In an indirect enzyme-linked immunosorbent assay (ELISA), MCA 6AL20 (IgG1 isotype) reacted with RPL-40 (ALV subgroup A), avian myeloblastosis virus (AMV) (a mixture of subgroups A and B), Rous-associated virus (RAV)-2 (subgroup B), and Carr-Zilber strain of Rous sarcoma virus (CZ-RSV) (subgroup D) but not with Prague strain of RSV (PrC-RSV) (subgroup C) or the endogenous virus RAV-0 (subgroup E). MCA 6AL22 reacted as above and also reacted marginally with PrC-RSV. Both MCAs immunoprecipitated p19 from 35S-methionine-labeled chicken embryo fibroblasts (CEFs) infected with RPL-40 or RAV-1, but not from CEFs infected with RAV-0, thus identifying the viral structural protein p19 as a polypeptide with subgroup-specific epitopes. Both MCAs can be used to differentiate RPL-40 from RAV-0 infection either in an indirect antibody ELISA or by immunoprecipitation. A third MCA, 6AL42 (IgG2a isotype), reacted with the above viruses of subgroups A, B, C, and D at an antibody titer up to 1000-fold higher than with subgroup E RAV-0 virus in indirect ELISAs. MCA 6AL42 immunoprecipitated p27 from cells infected with RPL-40, RAV-1, or RAV-0. These MCAs are potentially useful in developing immunological tests for differentiation of ALV strains.
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PMID:Characterization of monoclonal antibodies to avian leukosis viruses. 301 99

Two different systems of dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in separate laboratories detected analogous patterns of dye bands in virions of avian myeloblastosis virus (AMV). At least 11 of the dye bands co-migrated with the major polypeptides reported in Rous sarcoma virus. Particles with the morphology of the AMV core component, obtained after exposure of AMV to the nonionic surfactant Sterox SL, contained major polypeptides p12, p27, p60, p64, p91, and p98. The polypeptide p12 has been previously shown to be the major constituent of the inner ribonucleoprotein (RNP) of the AMV core, and has been designated p12(N). Two RNP polypeptides, p64 and p91, co-electrophoresed with purified AMV DNA polymerase and have now been designated p64(P) and p91(P). The polypeptide p27 has been identified as a probable constituent of the core shell, and has accordingly now been designated p27(C). In comparison to virions of AMV, the AMV core component contained a greatly reduced amount of polypeptide p15 and appeared to lack a major polypeptide, p19. Consequently, these polypeptides may be associated either with the exterior of the core shell or the interior of the viral envelope. Glycopeptides were not detected in AMV cores, in agreement with earlier reports that they reside in external projections from the viral envelope.
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PMID:Structural studies of avian myeloblastosis virus: comparison of polypeptides in virion and core component by dodecyl sulfate-polyacrylamide gel electrophoresis. 412 94

Monospecific antiserum obtained from rabbits hyperimmunized against homogeneous p27 group specific protein purified from avian myeloblastosis virus was commercially procured and was then conjugated with fluorescein isothiocyanate. The conjugate was applied to spleens from naturally or experimentally infected chickens that had no evidence of lymphoid tumors. Fluorescence was usually localized in connective tissue of sheathed capillaries giving it a ring-like appearance. Sites of fluorescence corresponded to sites of greatest virus concentration as detected by electron microscopy, indicating that in such cases the group specific antigen may have been associated with virus particles. The group specific antigen could also be detected in the spleen by complement fixation and results of this test usually agreed with the immunofluorescent test and with the phenotypic mixing test which detects exogenous lymphoid leukosis virus.
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PMID:Lymphoid leukosis: detection of group specific viral antigen in chicken spleens by immunofluorescence and complement fixation. 618 43

We have analyzed the avian myeloblastosis virus proteins in two types of leukemic myeloblasts: established myeloblastic cell lines (DU 1765 and DU 11157) and leukemic myeloblasts obtained from the peripheral blood of a leukemic C/E Spafas chicken (no. 21957). Using monospecific antisera for immunoprecipitation and polyacrylamide gel electrophoresis, we have detected gag gene-related proteins in the myeloblasts. The DU 1765 and DU 11157 cells contained a p100 protein which possessed antigenic determinants of the viral proteins p27, p19, p15, and p12. The p100 was not found in leukemic myeloblasts from Spafas chickens, and pulse-chase experiments showed that the p100 was not a precursor for the viral proteins. However, the p100 is present in uninfected line 15 chicken embryos. A pr76-like protein was identified in DU 1765 cells but migrated slightly further into gels than the pr76 of Spafas-derived leukemic myeloblasts. The Spafas-derived myeloblasts produced a pr60, whereas the DU 1765 cells contained instead a related protein of 62,000 daltons. Using anti-avian myeloblastosis virus gp85 sera, a glycoprotein of 120,000 daltons (gp120) was detected in all the tested leukemic myeloblasts. The gp120 was also present, in low amounts, in uninfected embyonic spleen and yolk sac cells. The anti-gp85 sera also precipitated a 27,000-dalton protein (h27) in these same cells. Both the gp120 and h27 could not be detected in either uninfected or myeloblastosis-associated virus-infected fibroblasts. Limited peptide hydrolysis revealed that h27 is different from the viral structural protein p27. In conclusion, monospecific antisera for gag and env gene products of avian myeloblastosis virus did not precipitate any unique or aberrant avian myeloblastosis virus protein from leukemic myeloblasts.
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PMID:Avian myeloblastosis virus proteins in leukemic chicken myeloblasts. 625 37


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