Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.11.1 (protein kinase)
 81,284 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Polyproteins (gag-fes) encoded by the Synder-Theilen (ST) and the Gardner-Arnstein (GA) strains of feline sarcoma virus (FeSV) were previously shown to be associated with mink or rat cells that were nonproductively transformed in vitro. In the present study we demonstrated that the same gag-fes proteins were found in cat cells transformed in vitro. Of greater importance, these transformation-related proteins were also in cells taken from fresh biopsies of FeSV-induced tumors. Cells from fibrosarcomas induced with ST-FeSV had gag-fes proteins that were characteristic of this strain. Fibrosarcomas and melanomas were induced with GA-FeSV and both types of tumors contained the protein that is characteristic of cells transformed in vitro with this virus. Expression of these proteins in cultured tumor cells appeared to be independent of the passage level. Based on two-dimensional tryptic peptide analysis, the gag-fes proteins of cat tumor cells appeared to be indistinguishable from those found in cells transformed in vitro. The polyproteins of the cat tumor cells have a closely associated protein kinase activity, as demonstrated in the in vitro assay, and phosphorylated tyrosine residues. Gag-fes proteins of either the ST or GA class were not present in cell cultures initiated from five spontaneous cat tumors.
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PMID:Feline sarcoma virus-specific transformation-related proteins and protein kinase activity in tumor cells. 618 75

Protein phosphorylation by a tyrosine-specific kinase is now recognized as a common event in retrovirus-transformed cells. We report in this communication that the feline sarcoma virus (FeSV) encoded transformation-specific proteins (gag-fes fusion proteins) and their associated protein kinases are also found in the FeSV in vivo induced tumor preparations, either in the form of fresh tumor homogenate or in the form of cultured cells. With the combined use of subcellular fractionation and detergent extraction we found that the protein kinase activity was present in both the membrane fraction (P100) and the cytosol (S100). The gag-fes proteins of two different strains of FeSV were found to associate with the cell framework to different degrees, suggesting that the specific conformational presentation of these proteins may be dictated by the unique portion of each polyprotein. The same gag-fes transformation related proteins could be immunoprecipitated with antiserum to phosphotyrosine.
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PMID:Detection and localization of a phosphotyrosine-containing onc gene product in feline tumor cells. 619 Jul 15

Fujinami sarcoma virus (FSV) and PRCII are avian sarcoma viruses which share cellularly derived v-fps transforming sequences. The FSV P140gag-fps gene product is phosphorylated on three distinct tyrosine residues in transformed cells or in an in vitro kinase reaction. Three variants of FSV, and the related virus PRCII which lacks about half of the v-fps sequence found in FSV, encode gene products which are all phosphorylated at tyrosine residues contained within identical tryptic peptides. This indicates a stringent conservation of amino acid sequence at the tyrosine phosphorylation sites which presumably reflects the importance of these sites for the biologic activity of the transforming proteins. Under suitable conditions the proteolytic enzymes p15 and V8 protease each introduce one cut into FSV P140, p15 in the N-terminal gag-encoded region and V8 protease in the middle of the fps-encoded region. Using these enzymes we have mapped the major site of tyrosine phosphorylation to the C-terminal end of the fps region of FSV P140gag-fps. A second tyrosine phosphorylation site is found in the fps region of FSV P140 isolated from transformed cells, and a minor tyrosine phosphorylation site is found in the N-terminal gag-encoded region. Our results suggest that the C-terminal fps-encoded region is required for expression of the tyrosine-specific protein kinase activity.
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PMID:Localization and characterization of phosphorylation sites of the Fujinami avian sarcoma virus and PRCII virus transforming proteins. 619 Aug 24

A new feline sarcoma virus designated Theilen-Pedersen (TP1-FeSV) has been isolated from a spontaneous, slowly growing fibrosarcoma of a domestic short-haired 4-year-old castrated cat. The virus codes for a gag-onc fusion protein of 83,000 molecular weight phosphorylated in vivo at serine, threonine, and tyrosine residues. Cells transformed in vitro with TP1-FeSV exhibit five- to 10-fold elevated levels of phosphotyrosine over FeLV-infected cells. The gag-onc polyprotein has associated with it a tyrosyl protein kinase activity which in vitro results in autophosphorylation of the molecule at tyrosine residues. The fusion protein cannot be labeled metabolically with [3H]glucosamine and tunicamycin has no effect on the electrophoretic mobility of the in vivo [32P]orthophosphate-labeled fusion protein. The fusion protein, in common with the gag precursor Pr65gag, can be metabolically labeled with palmitic acid.
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PMID:Biological and biochemical characterization of a new isolate of feline sarcoma virus: Theilen-Pedersen (TP1-FeSV). 620 83

The only known product of the Snyder-Theilen strain of feline sarcoma virus (ST-FeSV) is a 85,000-dalton protein, designated ST P85, that contains feline leukemia virus gag gene encoded proteins (p15, p12, and a fragment of p30) and a sarcoma virus-specific polypeptide. Antibodies directed against the latter immunoprecipitated a 92,000-dalton phosphoprotein (NCP 92) expressed at low levels in normal feline embryo fibroblasts as well as in feline cells of epithelial or lymphoid origin. Normal cellular proteins crossreactive with ST P85 were also detected in cell lines from various other mammalian species. These results suggest that the ST-FeSV sequences encoding for the sarcoma virus-specific domain of ST P85 originated from an evolutionarily conserved cellular gene expressed in cells of independent differentiation lineage. Immunoprecipitates containing ST-FeSV P85 exhibited a protein kinase activity that specifically phosphorylated tyrosine residues. The physiological significance of this finding is illustrated by the finding that phosphotyrosine is an intrinsic component of ST P85. Furthermore, 5- to-fold higher levels of this unusual phosphorylated amino acid were present in ST-FeSV transformants than in uninfected control cells. Phosphorylation of tyrosine residues appears to be associated with cellular transformation caused by Rous sarcoma virus and Abelson murine leukemia virus. Thus, independent transforming virus isolates from birds, mice, and cats may utilize common pathways in exerting their oncogenic potential.
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PMID:Origin and functional properties of the major gene product of the Snyder-Theilen strain of feline sarcoma virus. 625 60

The Y73 strain of avian sarcoma virus recently isolated in Japan is defective in replication and is associated with subgroup A leukosis virus (YAV). The virus caused sarcoma but not acute leukosis when inoculated into chickens. Studies on the viral RNA showed that a 26S RNA, etimated to be 4.8 kilobases long, was Y73 viral RNA carrying a transforming gene. The 26S RNA has sequences in common with the RNA of an avian leukosis virus but no homology with the src gene sequence of avian sarcoma virus (ASV). Thus, Y73 has a unique sarcoma-inducing gene. A phosphorylated polyprotein of 90,000 daltons (p90) was immunoprecipitated from extracts of Y73-transformed chicken embryo cells by a variety of antisera reacting with gag gene products. When a bacteria-bound immunocomplex containing the p90 protein was incubated with [gamma-32P]ATP, the Y73-specific p90 and the IgG heavy chain were phosphorylated by a p90-associated protein kinase. The amino acid phosphorylated in vitro was exclusively tyrosine in both cases, whereas p90 phosphorylated in vivo contained phosphoserine as a major phospho amino acid with traces of phosphotyrosine and phosphothreoine.
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PMID:Characterization of Y73, an avian sarcoma virus: a unique transforming gene and its product, a phosphopolyprotein with protein kinase activity. 625 80

Mink cells nonproductively-infected with the weakly-transforming T-8 isolate of murine leukemia virus (MuLV) express a 110,000 mol wt polyprotein designated T-8 P110. By immunoprecipitation analysis, T-8 P110 is shown to contain AKR-MuLV amino terminal gag gene-specific components (p15, p12) but to lack p30, p10, gp70, and p15(E) antigenic determinants. These observations are further substantiated by tryptic peptide analysis indicating T-8 P110 to share approximately six lysine-containing tryptic peptides with AKR-MuLV Pr65gag, and none with AKr-MuLV Pr82env. Furthermore, of seven methionine-containing T-8 P110 tryptic peptides, at least four can be conclusively shown not to be present in either AKr-MuLV Pr180gag/pol or Pr82env. A clonal mink cell line nonproductively infected by T-8, and expressing high levels of P110, although not morphologically transformed, is shown to lack elevated levels of tyrosine-specific protein kinase activity and reduction of epidermal growth factor binding sites characteristic of cells transformed by many other RNA-transforming viruses. These findings argue either that the T-8 viral genome contains acquired cellular sequences encoding a portion of P110, or that T-8 P110 represents an inphase deletion of AKR-MuLV Pr180gag/pol with extensive posttranlational modification and that an as yet unidentified protein is responsible for T-8 associated transformation.
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PMID:Identification of tryptic peptides unique to a 110,000-molecular weight polyprotein encoded by the T-8 isolate of murine leukemia virus. 625 65

Fujinami sarcoma virus (FSV), a newly characterized avian sarcoma virus, produces a protein of 140,000 daltons (p140) in infected cells. p140 is the product of a fused gene consisting of a part of the gag gene of avian retrovirus and FSV-unique sequences which are not related to the src sequences of Rous sarcoma virus. In vivo, p140 was found to be phosphorylated at both serine and tyrosine residues. Immunoprecipitates of p140 with antiserum against gag gene-coded proteins had a cyclic nucleotide-independent protein kinase activity which phosphorylated p140 itself, rabbit IgG of the immune complex and alpha-casein, an externally added soluble protein substrate. The phosphorylation was specific to tyrosine of the substrate proteins. p140 was phosphorylated in vitro at the same two tyrosine residues that were phosphorylated in vivo. The phosphate transferred to tyrosine residues of p140 forms a stable bond: it does not turn over during the kinase reaction, and the 32P-phosphate of p140 labeled in vitro or in vivo is not transferred to alpha-casein. FSV-p140 differs from p60src, the transforming protein of Rous sarcoma virus, in its marked preference of Mn2+ to Mg2+ ions, and in its inability to use GTP instead of ATP as the donor of gamma-phosphate.
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PMID:Characterization of protein kinase activity associated with the transforming gene product of Fujinami sarcoma virus. 625 96

Cells infected by one strain of Fujinami sarcoma virus (FSV) are transformed at 38 degrees C but are phenotypically normal at 41.5 degrees C. FSV encodes a 140,000 molecular weight protein (P140) with gag gene-related and FSV-specific peptide sequences. At 41.5 degrees C, P140 is weakly phosphorylated at serine residues, and is inactive in the immune complex protein kinase assay. At 38 degrees C, P140 is highly phosphorylated, contains phosphotyrosine in addition to phosphoserine, and in the immune complex kinase assay becomes phosphorylated at three tyrosine residues. Phosphorylation of cellular polypeptides at tyrosine residues in FSV-infected cells is also temperature-sensitive. These observations indicate that P140 is the transforming protein of FSV and that protein phosphorylation at tyrosine residues is involved in transformation by this virus.
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PMID:A strain of Fujinami sarcoma virus which is temperature-sensitive in protein phosphorylation and cellular transformation. 625 97

CDF1, (BALB/c X DBA/2)F1, mice were repeatedly inoculated with transplantable mouse Rous sarcoma (SR-CDF1) cells which were half-killed by 60Co-irradiation beforehand to attain prolonged immunization. The sera obtained from these mice contained antibodies against the src and gag gene products of Rous sarcoma virus (RSV). On the other hand, Fischer rats inoculated with syngeneic rat Rous cells transformed by Bryan high titer strain of RSV (BH(-)-3Y1) produced antibodies against the gag gene products but not the src gene product of RSV. As a substrate for the protein kinase associated with the src gene product, mouse IgG was found to be much less efficient than rabbit IgG when assayed in immunoprecipitates. Several other properties of the mouse antiserum were described.
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PMID:Antisera from mice and rats incubated with syngeneic Rous sarcoma cells. 625 86


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