scholarly journals Two structurally and functionally different forms of the transforming protein of PRC II avian sarcoma virus.

1982 ◽  
Vol 2 (8) ◽  
pp. 890-896 ◽  
Author(s):  
B Adkins ◽  
T Hunter
Keyword(s):  
Virus Genome ◽  
Specific Protein ◽  
Protein Kinase Activity ◽  
Avian Sarcoma Virus ◽  
Nonionic Detergent ◽  
Sarcoma Virus ◽  
Infected Cells ◽  
Avian Sarcoma ◽  
Peptide Maps ◽  
Specific Protein Kinase

The primary translation product of the PRC II avian sarcoma virus genome is a protein of 105,000 daltons (P105), and we have previously shown that approximately 50% of the P105 molecules are converted to molecules of 110,000 daltons (P110) by posttranslational modification. Fractionation of PRC II-infected cells showed that P105 was contained primarily in a nonionic detergent-soluble compartment, whereas P110 partitioned almost exclusively with a nonionic detergent-insoluble or crude cytoskeletal fraction. The tyrosine-specific protein kinase activity previously observed in immunoprecipitates which presumably contained both P110 and P105 was found predominantly in the P110-containing immunoprecipitates made from the cytoskeletal fraction and was essentially absent from the P105-containing immunoprecipitates prepared from the soluble fraction. Individual analysis of 32P-labeled P110 and P105 prepared by this fractionation technique revealed that P110 contained more phosphotyrosine per mole of protein than did P105. Examination of the tryptic peptide maps of 32P-labeled P110 and P105 suggested that the additional phosphotyrosine in P110 resulted from phosphorylation at discrete sites within the protein. From these experiments, we conclude that PRC II-infected cells contain two discrete forms, P105 and P110, of the transforming protein and that each of these proteins exhibits distinct structural and functional characteristics.

Two structurally and functionally different forms of the transforming protein of PRC II avian sarcoma virus

1982 ◽  
Vol 2 (8) ◽  
pp. 890-896
Author(s):  
B Adkins ◽  
T Hunter
Keyword(s):  
Virus Genome ◽  
Specific Protein ◽  
Protein Kinase Activity ◽  
Avian Sarcoma Virus ◽  
Nonionic Detergent ◽  
Sarcoma Virus ◽  
Infected Cells ◽  
Avian Sarcoma ◽  
Peptide Maps ◽  
Specific Protein Kinase

The primary translation product of the PRC II avian sarcoma virus genome is a protein of 105,000 daltons (P105), and we have previously shown that approximately 50% of the P105 molecules are converted to molecules of 110,000 daltons (P110) by posttranslational modification. Fractionation of PRC II-infected cells showed that P105 was contained primarily in a nonionic detergent-soluble compartment, whereas P110 partitioned almost exclusively with a nonionic detergent-insoluble or crude cytoskeletal fraction. The tyrosine-specific protein kinase activity previously observed in immunoprecipitates which presumably contained both P110 and P105 was found predominantly in the P110-containing immunoprecipitates made from the cytoskeletal fraction and was essentially absent from the P105-containing immunoprecipitates prepared from the soluble fraction. Individual analysis of 32P-labeled P110 and P105 prepared by this fractionation technique revealed that P110 contained more phosphotyrosine per mole of protein than did P105. Examination of the tryptic peptide maps of 32P-labeled P110 and P105 suggested that the additional phosphotyrosine in P110 resulted from phosphorylation at discrete sites within the protein. From these experiments, we conclude that PRC II-infected cells contain two discrete forms, P105 and P110, of the transforming protein and that each of these proteins exhibits distinct structural and functional characteristics.

Esh avian sarcoma virus codes for a gag-linked transformation-specific protein with an associated protein kinase activity

Virology ◽  
1981 ◽  
Vol 111 (2) ◽  
pp. 386-400 ◽  
Author(s):  
Jacques Ghysdael ◽  
James C. Neil ◽  
Alfred M. Wallbank ◽  
Peter K. Vogt
Keyword(s):  
Protein Kinase ◽  
Kinase Activity ◽  
Specific Protein ◽  
Protein Kinase Activity ◽  
Avian Sarcoma Virus ◽  
Sarcoma Virus ◽  
Avian Sarcoma

Isolation of an avian sarcoma virus-specific protein kinase from virus particles

Virology ◽  
1981 ◽  
Vol 110 (2) ◽  
pp. 333-343 ◽  
Author(s):  
Masatoshi-Koji Owada ◽  
Peter Donner ◽  
Angela Scott ◽  
Karin Welling
Keyword(s):  
Protein Kinase ◽  
Specific Protein ◽  
Avian Sarcoma Virus ◽  
Virus Particles ◽  
Sarcoma Virus ◽  
Avian Sarcoma ◽  
Specific Protein Kinase

Towards a molecular description of cell transformation by avian sarcoma virus

1980 ◽  
Vol 210 (1180) ◽  
pp. 387-396 ◽  
Keyword(s):  
Protein Kinase ◽  
Protein Phosphorylation ◽  
Molecular Mass ◽  
Cellular Protein ◽  
Transformed Cells ◽  
Relative Molecular Mass ◽  
Protein Kinase Activity ◽  
Avian Sarcoma Virus ◽  
Sarcoma Virus ◽  
Avian Sarcoma

The avian sarcoma virus transforming gene product has been identified and partially purified from extracts of transformed cells. It is a phosphoprotein with a relative molecular mass of 60 000 (pp60 src ) with two major sites of phosphorylation. pp60 src appears to be a cyclic-AMP-independent protein kinase as judged by protein phosphorylation with partly purified fractions. The specificity of the phosphorylation observed was judged by inhibition with anti-pp60 src IgG but not by normal IgG and by the fact that the protein kinase activity isolated from ts transformation-mutant infected cells was more thermolabile than that from wild-type transformed cells, thus showing more directly the origin of the enzymic activity. A cellular protein substrate of pp60 src has been identified as a 34000 molecular mass protein. These data together suggest that protein phosphorylation by pp60 src may be a function of the molecule that plays a major role in transformation.

scholarly journals Expression of the mammalian c-fes protein in hematopoietic cells and identification of a distinct fes-related protein.

1985 ◽  
Vol 5 (10) ◽  
pp. 2543-2551 ◽  
Author(s):  
I MacDonald ◽  
J Levy ◽  
T Pawson
Keyword(s):  
Protein Kinase ◽  
Kinase Activity ◽  
Human Peripheral Blood ◽  
Hematopoietic Cells ◽  
Specific Protein ◽  
Protein Kinase Activity ◽  
Sarcoma Virus ◽  
Human And Mouse ◽  
Specific Protein Kinase

The avian c-fps and mammalian c-fes proto-oncogenes are cognate cellular sequences. Antiserum raised against the P140gag-fps transforming protein of Fujinami avian sarcoma virus specifically recognized a 92,000-Mr protein in human and mouse hematopoietic cells which was closely related in structure to Snyder-Theilen feline sarcoma virus P87gag-fes. This polypeptide was apparently the product of the human c-fes gene and was therefore designated p92c-fes. Human p92c-fes was associated with a tyrosine-specific protein kinase activity in vitro and was capable of both autophosphorylation and phosphorylation of enolase as an exogenous protein substrate. The synthesis of human and mouse p92c-fes was largely, though not entirely, confined to myeloid cells. p92c-fes was expressed to relatively high levels in a multipotential murine myeloid cell line, in more mature human and mouse granulocyte-macrophage progenitors, and in differentiated macrophage like cells as well as in the mononuclear fraction of normal and leukemic human peripheral blood. p92c-fes was not found in erythroid cells, with the exception of a human erythroleukemia line which retains the capacity to differentiate into macrophage like cells. These results suggest a normal role for the p92c-fes tyrosine kinase in hematopoiesis, particularly in granulocyte-macrophage differentiation. In addition, a distinct 94,000-Mr polypeptide, antigenically related to p92c-fes, was identified in a number of hematopoietic and nonhematopoietic human and mouse cells and was also found to be associated with a tyrosine-specific protein kinase activity.

Avian Sarcoma Virus Transformed Hamster Cells made Resistant to Ethidium Bromide

1974 ◽  
Vol 16 (3) ◽  
pp. 603-621
Author(s):  
C. ALTANER ◽  
J. MATOSKA
Keyword(s):  
Cell Lines ◽  
Ethidium Bromide ◽  
Virus Genome ◽  
Resistant Cell ◽  
Resistant Cell Line ◽  
Avian Sarcoma Virus ◽  
Sarcoma Virus ◽  
Original Cell ◽  
Avian Sarcoma ◽  
Resistant Cells

Hamster cells transformed with the Schmidt-Ruppin strain of avian sarcoma virus were selected for resistance to ethidium bromide (EB). The resistant cell lines proliferated in the presence of up to 30 µg/ml EB. From avian sarcoma virus-transformed hamster cells already resistant to bromodeoxy-uridine (BrdU), ethidium bromide-resistant cells which were able to grow in 10 µg/ml EB were also prepared. These cells remain deficient in thymidine kinase activity and are suitable for selective preparation of hybrid cells. The EB resistance was genetically stable. The EB-resistant cell lines, and doubly resistant cells (BrdU, EB) showed no differences in mitochondrial ultrastructure compared with the original cell lines. Thymidine incorporation into mitochondrial DNA was not influenced by EB resistance. All resistant cell lines, including the doubly resistant cell line, contained the avian sarcoma virus genome. The number of cells needed for positive rescue experiments for avian sarcoma virus genome by cell fusion with permissive chicken embryo cells was the same as with the original cell lines. The single EB-resistant cell lines contained R-type virus-like particles, while in BrdU-resistant and doubly resistant cells the R-type particles were absent. The possible nature of EB resistance is discussed.

scholarly journals Purified polyoma virus medium T antigen has tyrosine-specific protein kinase activity but no significant phosphatidylinositol kinase activity.

1986 ◽  
Vol 6 (6) ◽  
pp. 1866-1874 ◽  
Author(s):  
W Koch ◽  
A Carbone ◽  
G Walter
Keyword(s):  
Protein Kinase ◽  
Kinase Activity ◽  
Specific Protein ◽  
T Antigen ◽  
Polyoma Virus ◽  
Protein Kinase Activity ◽  
Phosphatidylinositol Kinase ◽  
Sarcoma Virus ◽  
Transforming Proteins ◽  
Specific Protein Kinase

Medium T antigen, the transforming protein of polyoma virus, is associated with pp60c-src and strongly activates its tyrosine-specific protein kinase activity. We investigated whether the medium T-pp60c-src complex is also associated with an activity that phosphorylates the membrane phospholipid phosphatidylinositol, as shown for pp60v-src and p68v-ros, the transforming proteins of Rous sarcoma virus and avian sarcoma virus UR2, respectively. Medium T was purified by affinity chromatography from extracts of polyoma virus-infected mouse fibroblasts. It was bound to antibodies against a peptide corresponding to the carboxy terminus of medium T and released from the immune complex with an excess of the same peptide. In a second step, the partially purified medium T was bound to antibodies against another peptide corresponding to an internal region of medium T and released with excess peptide. Further purification was carried out with a monoclonal antibody against pp60c-src. Samples from each purification step were examined for protein kinase and phosphatidylinositol kinase activity. The highly purified preparations of the medium T-pp60c-src complex showed very low levels of phosphatidylinositol kinase activity, and no difference between medium T from transforming viruses and nontransforming hr-t mutants was detected. In contrast, protein kinase activity was associated with medium T purified from transforming viruses but not from hr-t mutants.

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