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.

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.

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.

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

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.

Invariant phosphorylation of the Saccharomyces cerevisiae Cdc28 protein kinase

1988 ◽  
Vol 8 (7) ◽  
pp. 2976-2979
Author(s):  
J A Hadwiger ◽  
S I Reed
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Kinase Activity ◽  
Specific Protein ◽  
Protein Kinase Activity ◽  
Cycle Arrest ◽  
Phosphorylation Level ◽  
Proposed Regulation ◽  
Specific Protein Kinase

The phosphorylation level of the Saccharomyces cerevisiae Cdc28 protein remained invariant under conditions that resulted in cell cycle arrest in the G1 phase and loss of Cdc28-specific protein kinase activity when the activity was assayed in vitro. These results are in contrast to the proposed regulation of the homologous Cdc2 protein kinase of Schizosaccharomyces pombe.

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