A third class of avian sarcoma viruses, defined by related transformation-specific proteins of Yamaguchi 73 and Esh sarcoma viruses (original) (raw)
Related papers
Cell, 1981
Transformation of chicken cells by Fujinami sarcoma virus (FSV), PRC II or Y73 (three independently isolated avian sarcoma viruses that are replication-defective and lack the Rous sarcoma virus src gene) resulted in significant elevation (4-13 fold) of phosphotyrosine levels in cellular protein. The gag-related proteins encoded by these avian sarcoma viruses (ASVs) were all associated with tyrosine-specific protein kinase activity when assayed in immune complexes and were phosphorylated at both tyrosine and serine residues in vivo. Both the phosphotyrosine level in protein of FSVinfected cells and the protein kinase activity assayed in immune complexes containing the FSV protein P140 were temperature-sensitive. The presumed transforming proteins of these ASVs were compared with those of Rous sarcoma virus (RSV), Abelson murine leukemia virus and the Snyder-Theilen and Gardner-Arnstein strains of feline sarcoma virus (FeSV), which have previously been associated with tyrosine-specific protein kinase activity. FSV and PRC II proteins were shown to be structurally related to one another and to the FeSV proteins by tryptic peptide mapping and by immunological studies. No homology was observed, however, between the transforming proteins of RSV, Y73, Abelson murine leukemia virus and the FSV/PRC II/ FeSV class, suggesting there may be at least four classes of retroviruses whose transformation mechanisms involve aberrant phosphorylation of cellular protein at tyrosine residues.
Journal of Virology, 1981
The transformation-specific protein pp60 src coded for by avian sarcoma viruses and its associated protein kinase activity is present in virus particles of Rous sarcoma virus, Schmidt-Ruppin strain, subgroup D. Quantitative comparison of the immunoglobulin G-phosphorylating activity in Schmidt-Ruppin D virus and Schmidt-Ruppin D virus-transformed fibroblasts indicated that there was two- to fourfold less activity in the virus particles. Disruption of virus particles with nonionic detergent demonstrated that the protein kinase activity fractionated together with the viral membrane protein gp85. Therefore, viral membranes were isolated by floating detergent-disrupted virus through a discontinuous sucrose density gradient. At a characteristic density corresponding to 26% sucrose, viral membranes were identified by the radioactively labeled viral glycoprotein and furthermore by the membrane marker enzyme Na + -K + -stimulated, Mg 2+ -activated ATPase and were visualized by electron micr...
Journal of Cellular Biochemistry, 1982
The biological and biochemical properties of the transformation-specific proteins of three avian oncornaviruses with different oncogenic potentials were compared, namely the gag-myc protein of the avian myelocytomatosis virus MC29, the gagerb A protein of the avian erythroblastosis virus AEV, and the gag-fis protein of Fujinami sarcoma virus FSV. These oncogenes were analyzed in transformed fibroblasts that expressed only the transforming proteins but showed no virus replication. Monoclonal antibodies against the viral structural protein p19, which is the N-terminus of the proteins, were used for indirect immunofluorescence, for immunoprecipitation of the proteins from subcellular fractions, and for immunoaffinity column chromatography. With this last method a 3000-fold purification of the proteins was obtained. By indirect immunofluorescence it was shown that the gag-myc protein was located in the nucleus, and bound to DNA after purification. The gag-erb A protein was not nuclear but probably located in the cytoplasm and did not bind to DNA after purification. Neither of the two proteins exhibited protein kinase activity. In contrast, the gag-fps protein did not bind to DNA but showed protein kinase activity after purification. It was not located in the nucleus either.
Proceedings of the National Academy of Sciences, 1980
All vertebrate cells have been shown to contain a gene, sarc, that has some homology with the transforming gene of Rous sarcoma virus, src. We have com ared the polypeptide products of the sarc gene, p608arc, of human, mouse, and chicken cells with the polymorphic polypeptide product of the src gene, p60'rc, of several strains of Rous sarcoma virus by two-dimensional peptide mapping. p60sarc from chicken cells was clearly related to every viral p608'7. Eleven of its 13 methionine-containing tryptic peptides were present in some viral p60Orc. Conversely, the other two peptides were not present in any p60'tc we have examined so far. The 11 peptides from p60'7"c of chickens that were shared with viral p6OOrc, however, were not all present in any single viral p6087'c. These 11 peptides most closely resemble those in the p60'rcs of B77 virus and the Prague strain of Rous sarcoma virus. These data
Changes in protein phosphorylation in Rous sarcoma virus-transformed chicken embryo cells
Molecular and cellular biology, 1981
Rous sarcoma virus encodes a tyrosine-specific protein kinase (p60src) which is necessary for cell transformation. To identify substrates for this kinase, we set out to detect phosphotyrosine-containing proteins in Rous sarcoma virus-transformed chicken embryo cells, making use of the known alkali stability of phosphotyrosine. 32P-labeled phosphoproteins were separated by isoelectric focusing and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The gels were then incubated in alkali. Using this procedure with normal cells, we detected a total of about 190 alkali-resistant phosphoproteins. In Rous sarcoma virus-transformed cells, five phosphoproteins were found which were not detectable in normal cells. Two of these are probably structural proteins of the virus. The other three transformation-dependent phosphoproteins, and four other phosphoproteins which were elevated by transformation, all contained phosphotyrosine. Increased phosphorylation of these proteins did not occu...
Journal of Virology
The gag gene-related, nonstructural proteins of three avian acute leukemia viruses (namely, myelocytomatosis viruses MC29 and CMII and avian erythroblastosis virus) and of avian Fujinami sarcoma virus (FSV) isolated by immunoprecipitation from cellular lysates with anti-gag serum were shown to be phosphoproteins in vivo. The specific 32P radioactivity of the nonstructural proteins of MC29, CMII, and FSV was significantly higher than that of helper viral, intracellular gag proteins. Two of these proteins, i.e., the 140,000-dalton FSV and the 110,000-dalton MC29 proteins, were also phosphorylated in vitro by a kinase activity associated with immunocomplexes. This kinase activity is either separated from these proteins or inactivated by incubation of cellular lysates with normal serum followed by adsorption to staphylococcal protein A or sedimentation at 100,000 x g or both. It remains to be resolved whether the 110,000-dalton MC29 and 140,000-dalton FSV proteins, in addition to being substrates for phosphorylation, also have intrinsic kinase activity.
Polymorphism of avian sarcoma virus src proteins
Journal of Virology
The src gene products of seven different avian sarcoma viruses were compared. In vitro translation of virion RNA yielded products identified unambiguously as p60C in the case of two stocks of the Schmidt-Ruppin strain, three stocks of the Prague strain, the Bryan strain, and the Bratislava 77 strain of avian sarcoma virus. Differences in the electrophoretic mobility of these seven p608rc proteins in sodium dodecyl sulfate-polyacrylamide gels, corresponding to variation in the apparent molecular weights ranging from 56,000 to 60,500, were observed. Antigenic variability was also found; only three of the seven viruses tested encoded a p608, which was precipitated by antisera derived from rabbits bearing tumors induced by the Schmidt-Ruppin strain of Rous sarcoma virus. Examination of the methionine-containing tryptic peptides of the seven p6Osrc proteins by twodimensional mapping revealed four common peptides but marked variability in the five to eight other peptides in each protein. Clear differences in the peptide maps of p60`r were observed, both between different strains of virus and within strains. In the three cases examined, p60Brc synthesized in transformed cells was found to be essentially identical to that synthesized in vitro. We conclude that there is significant polymorphism in the p60src proteins of the avian sarcoma viruses.
Journal of Virology
In vitro translation of Rous sarcoma virus virion RNA resulted in the synthesis of a protein kinase which, when immunoprecipitated with antitumor serum, phosphorylated the immunoglobulin heavy chain. Even though in vitro translation of virion RNA resulted in the synthesis of a number of polypeptides which were recognized by antitumor serum, control experiments demonstrated that an immunoprecipitable protein kinase activity was found only when an immunoprecipitable p6O', the polypeptide product of the src gene, was synthesized. A protein kinase with similar properties was therefore intimately associated with p6O0 which was synthesized in vitro in the reticulocyte lysate, just as it is with p6O' which is obtained from transformed chick and mnmalian cells. It is therefore highly unlikely that this association is artifactual. ts NY68 is a mutant of Rous sarcoma virus which is able to transform cells at 36 but not at 410C. In vitro translation of ts NY68 virion RNA at 300C resulted in efficient synthesis of immunoprecipitable p60w, but very inefficient synthesis of an immunoprecipitable protein kinase. The p60w obtained by in vitro translation of wild-type virion RNA was more than 20-fold more active as a protein kinase than was that obtained from ts NY68 RNA. The correlation in the case of ts NY68 of a deficiency in protein kinase activity with an inability to transform celLs at high temperature suggests that the protein kinase activity associated with p60w is indeed critical to cellular transformation.
Product of in vitro translation of the Rous sarcoma virus src gene has protein kinase activity
Journal of Virology, 1979
In vitro translation of Rous sarcoma virus virion RNA resulted in the synthesis of a protein kinase which, when immunoprecipitated with antitumor serum, phosphorylated the immunoglobulin heavy chain. Even though in vitro translation of virion RNA resulted in the synthesis of a number of polypeptides which were recognized by antitumor serum, control experiments demonstrated that an immunoprecipitable protein kinase activity was found only when an immunoprecipitable p60src, the polypeptide product of the src gene, was synthesized. A protein kinase with similar properties was therefore intimately associated with p60src which was synthesized in vitro in the reticulocyte lysate, just as it is with p60src which is obtained from transformed chick and mammalian cells. It is therefore highly unlikely that this association is artifactual. ts NY68 is a mutant of Rous sarcoma virus which is able to transform cells at 36 but not at 41 degrees C. In vitro translation of ts NY68 virion RNA at 30 d...