Properties of Moloney Sarcoma Virus-Specific p60 and its Detection in Transformed Cells

2015 ◽  
pp. 125-127
Author(s):  
G. F. Vande Woude ◽  
W. G. Robey ◽  
M. K. Oskarsson ◽  
D. K. Haapala ◽  
P. J. Fischinger ◽  
...  
Keyword(s):  
Transformed Cells ◽  
Sarcoma Virus ◽  
Moloney Sarcoma Virus

Increased secretion of type beta transforming growth factor accompanies viral transformation of cells

1985 ◽  
Vol 5 (1) ◽  
pp. 242-247
Author(s):  
M A Anzano ◽  
A B Roberts ◽  
J E De Larco ◽  
L M Wakefield ◽  
R K Assoian ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Growth Factor Receptor ◽  
Transformed Cells ◽  
Down Regulation ◽  
Untransformed Control ◽  
Transforming Growth Factor Receptor ◽  
Sarcoma Virus ◽  
Moloney Sarcoma Virus ◽  
Viral Transformation

Cells transformed by Harvey or Moloney sarcoma virus secrete at least 40 times as much type beta transforming growth factor as their respective untransformed control cells. The transformed cells bind only 20 to 50% as much type beta transforming growth factor as the control cells, suggesting that transformation causes down-regulation of the type beta transforming growth factor receptor.

scholarly journals Increased secretion of type beta transforming growth factor accompanies viral transformation of cells.

1985 ◽  
Vol 5 (1) ◽  
pp. 242-247 ◽  
Author(s):  
M A Anzano ◽  
A B Roberts ◽  
J E De Larco ◽  
L M Wakefield ◽  
R K Assoian ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Growth Factor Receptor ◽  
Transformed Cells ◽  
Down Regulation ◽  
Untransformed Control ◽  
Transforming Growth Factor Receptor ◽  
Sarcoma Virus ◽  
Moloney Sarcoma Virus ◽  
Viral Transformation

Cells transformed by Harvey or Moloney sarcoma virus secrete at least 40 times as much type beta transforming growth factor as their respective untransformed control cells. The transformed cells bind only 20 to 50% as much type beta transforming growth factor as the control cells, suggesting that transformation causes down-regulation of the type beta transforming growth factor receptor.

scholarly journals Tropomyosin isoforms in chicken embryo fibroblasts: purification, characterization, and changes in Rous sarcoma virus-transformed cells.

1985 ◽  
Vol 100 (3) ◽  
pp. 692-703 ◽  
Author(s):  
J J Lin ◽  
D M Helfman ◽  
S H Hughes ◽  
C S Chou
Keyword(s):  
Rous Sarcoma Virus ◽  
Chicken Embryo ◽  
Actin Binding ◽  
Transformed Cells ◽  
Two Dimensional ◽  
Tropomyosin Isoforms ◽  
Rous Sarcoma ◽  
Sarcoma Virus ◽  
Embryo Fibroblasts ◽  
Chicken Embryo Fibroblasts

Seven polypeptides (a, b, c, 1, 2, 3a, and 3b) have been previously identified as tropomyosin isoforms in chicken embryo fibroblasts (CEF) (Lin, J. J.-C., Matsumura, F., and Yamashiro-Matsumura, S., 1984, J. Cell. Biol., 98:116-127). Spots a and c had identical mobility on two-dimensional gels with the slow-migrating and fast-migrating components, respectively, of chicken gizzard tropomyosin. However, the remaining isoforms of CEF tropomyosin were distinct from chicken skeletal and cardiac tropomyosins on two-dimensional gels. The mixture of CEF tropomyosin has been isolated by the combination of Triton/glycerol extraction of monolayer cells, heat treatment, and ammonium sulfate fractionation. The yield of tropomyosin was estimated to be 1.4% of total CEF proteins. The identical set of tropomyosin isoforms could be found in the antitropomyosin immunoprecipitates after the cell-free translation products of total poly(A)+ RNAs isolated from CEF cells. This suggested that at least seven mRNAs coding for these tropomyosin isoforms existed in the cell. Purified tropomyosins (particularly 1, 2, and 3) showed different actin-binding abilities in the presence of 100 mM KCl and no divalent cation. Under this condition, the binding of tropomyosin 3 (3a + 3b) to actin filaments was significantly weaker than that of tropomyosin 1 or 2. CEF tropomyosin 1, and probably 3, could be cross-linked to form homodimers by treatment with 5,5'-dithiobis-(2-nitrobenzoate), whereas tropomyosin a and c formed a heterodimer. These dimer species may reflect the in vivo assembly of tropomyosin isoforms, since dimer formation occurred not only with purified tropomyosin but also with microfilament-associated tropomyosin. The expression of these tropomyosin isoforms in Rous sarcoma virus-transformed CEF cells has also been investigated. In agreement with the previous report by Hendricks and Weintraub (Proc. Natl. Acad. Sci. USA., 78:5633-5637), we found that major tropomyosin 1 was greatly reduced in transformed cells. We have also found that the relative amounts of tropomyosin 3a and 3b were increased in both the total cell lysate and the microfilament fraction of transformed cells. Because of the different actin-binding properties observed for CEF tropomyosins, changes in the expression of these isoforms may, in part, be responsible for the reduction of actin cables and the alteration of cell shape found in transformed cells.

Feline sarcoma virus polyprotein P115 binds a host phosphoprotein in transformed cells

Nature ◽  
1980 ◽  
Vol 286 (5771) ◽  
pp. 409-412 ◽  
Author(s):  
Fred. H. Reynolds ◽  
Wim J. M. Van de Ven ◽  
John R. Stephenson
Keyword(s):  
Transformed Cells ◽  
Sarcoma Virus ◽  
Virus Polyprotein

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.

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