scholarly journals Correlation between phosphorylation of a 34,000-molecular-weight protein, pp60src-associated kinase activity, and tumorigenicity in transformed and revertant vole cells.

1984 ◽  
Vol 4 (1) ◽  
pp. 212-215 ◽  
Author(s):  
J F Nawrocki ◽  
A F Lau ◽  
A J Faras
Keyword(s):  
Molecular Weight ◽  
Rous Sarcoma Virus ◽  
Kinase Activity ◽  
Cell Types ◽  
Cell Protein ◽  
Protein Kinase Activity ◽  
Rous Sarcoma ◽  
Tumorigenic Potential ◽  
Sarcoma Virus ◽  
Weight Protein

The phosphorylation of a 34,000-molecular-weight (34K) cell protein, purported to be a substrate of the avian retrovirus pp60src-associated protein kinase activity, was compared in three types of Rous sarcoma virus-infected vole cells: fully transformed cells, partial revertants which are morphologically normal in appearance but retain their tumorigenic potential, and full revertants which are similar to normal vole cells in all parameters including a lack of tumorigenicity. Although similar amounts of 34K protein are present in all three cell types, phosphorylation of the 34K protein was significantly reduced in the full revertant cell type. The reduced phosphorylation occurred at the tyrosine residue.

Correlation between phosphorylation of a 34,000-molecular-weight protein, pp60src-associated kinase activity, and tumorigenicity in transformed and revertant vole cells

1984 ◽  
Vol 4 (1) ◽  
pp. 212-215
Author(s):  
J F Nawrocki ◽  
A F Lau ◽  
A J Faras
Keyword(s):  
Molecular Weight ◽  
Rous Sarcoma Virus ◽  
Kinase Activity ◽  
Cell Types ◽  
Cell Protein ◽  
Protein Kinase Activity ◽  
Rous Sarcoma ◽  
Tumorigenic Potential ◽  
Sarcoma Virus ◽  
Weight Protein

The phosphorylation of a 34,000-molecular-weight (34K) cell protein, purported to be a substrate of the avian retrovirus pp60src-associated protein kinase activity, was compared in three types of Rous sarcoma virus-infected vole cells: fully transformed cells, partial revertants which are morphologically normal in appearance but retain their tumorigenic potential, and full revertants which are similar to normal vole cells in all parameters including a lack of tumorigenicity. Although similar amounts of 34K protein are present in all three cell types, phosphorylation of the 34K protein was significantly reduced in the full revertant cell type. The reduced phosphorylation occurred at the tyrosine residue.

scholarly journals Tyrosine phosphorylation of a 50K cellular polypeptide associated with the Rous sarcoma virus transforming protein pp60src.

1982 ◽  
Vol 2 (2) ◽  
pp. 199-206 ◽  
Author(s):  
T D Gilmore ◽  
K Radke ◽  
G S Martin
Keyword(s):  
Protein Kinase ◽  
Rous Sarcoma Virus ◽  
Kinase Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Fold Increase ◽  
Temperature Sensitive ◽  
Protein Kinase Activity ◽  
Rous Sarcoma ◽  
Defective Mutant ◽  
Sarcoma Virus

We have examined the phosphorylation of a 50,000-dalton cellular polypeptide associated with the Rous sarcoma virus (FSV) transforming protein pp60-src. It has been shown that pp60src forms a complex with two cellular polypeptides, an 89,000-dalton heat-shock protein (89K) and a 50,000-dalton phosphoprotein (50K). The pp60src-associated protein kinase activity phosphorylates at tyrosine residues, and the 50K polypeptide present in the complex contains phosphotyrosine and phosphoserine. These observations suggest that the 50K polypeptide may be a substrate for the protein kinase activity of pp60src. To examine this possibility, we isolated the 50K polypeptide by two-dimensional polyacrylamide gel electrophoresis from lysates of uninfected or virally infected cells. Tryptic phosphopeptide analysis indicated that the 50K polypeptide isolated by this method was the same polypeptide as that complexed to pp60src. In uninfected cells or cells infected by a transformation-defective mutant, the 50K polypeptide contained phosphoserine but little or no phosphotyrosine. In cells infected by Schmidt-Ruppin or Prague RSV, there was a 40- to 50-fold increase in the quantity of phosphotyrosine in the 50K protein. Thus, the phosphorylation of the 50K polypeptide at tyrosine is dependent on the presence of pp60src. However, the 50K polypeptide isolated from cells infected by temperature-sensitive mutants of RSV was found to be phosphorylated at tyrosine at both permissive and nonpermissive temperatures; this behavior is different from that of other substrates or putative substrates of the pp60src kinase activity. It is possible that the 50K polypeptide is a high-affinity substrate of pp60src.

Tyrosine phosphorylation of a 50K cellular polypeptide associated with the Rous sarcoma virus transforming protein pp60src

1982 ◽  
Vol 2 (2) ◽  
pp. 199-206
Author(s):  
T D Gilmore ◽  
K Radke ◽  
G S Martin
Keyword(s):  
Protein Kinase ◽  
Rous Sarcoma Virus ◽  
Kinase Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Fold Increase ◽  
Temperature Sensitive ◽  
Protein Kinase Activity ◽  
Rous Sarcoma ◽  
Defective Mutant ◽  
Sarcoma Virus

We have examined the phosphorylation of a 50,000-dalton cellular polypeptide associated with the Rous sarcoma virus (FSV) transforming protein pp60-src. It has been shown that pp60src forms a complex with two cellular polypeptides, an 89,000-dalton heat-shock protein (89K) and a 50,000-dalton phosphoprotein (50K). The pp60src-associated protein kinase activity phosphorylates at tyrosine residues, and the 50K polypeptide present in the complex contains phosphotyrosine and phosphoserine. These observations suggest that the 50K polypeptide may be a substrate for the protein kinase activity of pp60src. To examine this possibility, we isolated the 50K polypeptide by two-dimensional polyacrylamide gel electrophoresis from lysates of uninfected or virally infected cells. Tryptic phosphopeptide analysis indicated that the 50K polypeptide isolated by this method was the same polypeptide as that complexed to pp60src. In uninfected cells or cells infected by a transformation-defective mutant, the 50K polypeptide contained phosphoserine but little or no phosphotyrosine. In cells infected by Schmidt-Ruppin or Prague RSV, there was a 40- to 50-fold increase in the quantity of phosphotyrosine in the 50K protein. Thus, the phosphorylation of the 50K polypeptide at tyrosine is dependent on the presence of pp60src. However, the 50K polypeptide isolated from cells infected by temperature-sensitive mutants of RSV was found to be phosphorylated at tyrosine at both permissive and nonpermissive temperatures; this behavior is different from that of other substrates or putative substrates of the pp60src kinase activity. It is possible that the 50K polypeptide is a high-affinity substrate of pp60src.

scholarly journals Staurosporine inhibits tyrosine-specific protein kinase activity of Rous sarcoma virus transforming protein p60.

1987 ◽  
Vol 40 (5) ◽  
pp. 706-708 ◽  
Author(s):  
HIROFUMI NAKANO ◽  
EIJI KOBAYASHI ◽  
ISAMI TAKAHASHI ◽  
TATSUYA TAMAOKI ◽  
YASUKO KUZUU ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Rous Sarcoma Virus ◽  
Kinase Activity ◽  
Specific Protein ◽  
Protein Kinase Activity ◽  
Rous Sarcoma ◽  
Sarcoma Virus ◽  
Specific Protein Kinase

Lack of induction of neuroretinal cell proliferation by Rous sarcoma virus variants that carry the c-src gene

1985 ◽  
Vol 5 (10) ◽  
pp. 2856-2859
Author(s):  
H Iba ◽  
R Jove ◽  
H Hanafusa
Keyword(s):  
Cell Proliferation ◽  
Rous Sarcoma Virus ◽  
Kinase Activity ◽  
Cell Populations ◽  
Protein Kinase Activity ◽  
Morphological Transformation ◽  
Rous Sarcoma ◽  
Src Gene ◽  
Cellular Homolog ◽  
Sarcoma Virus

Expression of p60v-src of Rous sarcoma virus in cultured chicken embryo neuroretinal cells was previously shown to result in the transformation and sustained proliferation of normally quiescent cell populations. We show here that Rous sarcoma virus variants that encode p60c-src, the cellular homolog of p60v-src, lack the ability to induce morphological transformation and cell proliferation of cultured neuroretinal cells. Neuroretinal cells infected with c-src-containing viruses, however, possess no less p60 protein kinase activity assayed in the immune complex than those infected with the transformation-defective Rous sarcoma virus mutants PA101 or PA104, which do stimulate the growth of these cells.

Amino acid alterations within a highly conserved region of the Rous sarcoma virus src gene product pp60src inactivate tyrosine protein kinase activity

1984 ◽  
Vol 4 (5) ◽  
pp. 862-866
Author(s):  
D L Bryant ◽  
J T Parsons
Keyword(s):  
Amino Acid ◽  
Protein Kinase ◽  
Rous Sarcoma Virus ◽  
Kinase Activity ◽  
Mutant Virus ◽  
Protein Kinase Activity ◽  
Rous Sarcoma ◽  
Src Gene ◽  
Tyrosine Protein Kinase ◽  
Sarcoma Virus

Bisulfite mutagenesis techniques have been used to introduce single-point mutations within a region of the Rous sarcoma virus src gene defined by a BglI restriction endonuclease cleavage site. The mutants of Rous sarcoma virus that are produced by these techniques encode src proteins which contain single amino acid changes within a highly conserved amino acid sequence encompassing residues 430 to 433. DNA from the mutants CHpm26 ( Ala430 to Val), CHpm9 ( Pro431 to Ser), CHpm6 ( Glu432 to Lys), and CHpm65 ( Ala433 to Thr) each failed to transform chicken cells upon transfection, whereas DNA from CHpm59 (a third base alteration in the codon for Glu432 ) readily transformed chicken cells. Analysis of immune complexes containing the altered src proteins indicates that these proteins have decreased tyrosine protein kinase activity in vitro. In vivo labeling of cells infected with the mutant virus revealed diminished levels of the tyrosine-phosphorylated 34,000-molecular-weight protein. These data indicate that mutations within the sequence Ala430 - Pro431 - Glu432 - Ala433 lead to alterations in pp60src-specific tyrosine protein kinase activity and a concomitant loss of transforming potential of the mutant virus.

scholarly journals Lack of induction of neuroretinal cell proliferation by Rous sarcoma virus variants that carry the c-src gene.

1985 ◽  
Vol 5 (10) ◽  
pp. 2856-2859 ◽  
Author(s):  
H Iba ◽  
R Jove ◽  
H Hanafusa
Keyword(s):  
Cell Proliferation ◽  
Rous Sarcoma Virus ◽  
Kinase Activity ◽  
Cell Populations ◽  
Protein Kinase Activity ◽  
Morphological Transformation ◽  
Rous Sarcoma ◽  
Src Gene ◽  
Cellular Homolog ◽  
Sarcoma Virus

Expression of p60v-src of Rous sarcoma virus in cultured chicken embryo neuroretinal cells was previously shown to result in the transformation and sustained proliferation of normally quiescent cell populations. We show here that Rous sarcoma virus variants that encode p60c-src, the cellular homolog of p60v-src, lack the ability to induce morphological transformation and cell proliferation of cultured neuroretinal cells. Neuroretinal cells infected with c-src-containing viruses, however, possess no less p60 protein kinase activity assayed in the immune complex than those infected with the transformation-defective Rous sarcoma virus mutants PA101 or PA104, which do stimulate the growth of these cells.

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