| transforming properties and substrate specificities of the protein tyrosine kinase oncogenes ros and src and their recombinants. | to determine the sequences of the oncogenes src (encoded by rous sarcoma virus [rsv]) and ros (encoded by ur2) that are responsible for causing different transformation phenotypes and to correlate those sequences with differences in substrate recognition, we constructed recombinants of the two transforming protein tyrosine kinases (ptks) and studied their biological and biochemical properties. a recombinant with a 5' end from src and a 3' end from ros, called src x ros, transformed chicken embry ... | 1992 | 1321277 |
| the stimulation of quiescent rat fibroblasts by v-src and v-fps oncogenic protein-tyrosine kinases leads to the induction of a subset of immediate early genes. | the stimulation of quiescent murine fibroblasts by growth factors and by phorbol esters results in a rapid and transient transcriptional activation of a large group of so-called immediate early genes. several such genes were found to be induced in chicken embryo fibroblasts following activation of a temperature sensitive (ts) rous sarcoma virus v-src mutant following temperature shift (simmons et al., 1989). in contrast, the classical immediate early genes c-myc, c-fos and c-jun were essentially ... | 1991 | 1861868 |
| delineation of functional determinants in the transforming protein of fujinami sarcoma virus. | we analyzed linker insertion mutations throughout the 3' region of the v-fps gene of fujinami sarcoma virus to identify tyrosine kinase transforming protein (p130gag-fps) determinants that are important for catalysis and transforming activity and, in particular, to define residues that participate in substrate selection. mutations that encode kinase-active, transformation-defective v-fps alleles were recovered, defining sites in the transforming protein that may normally facilitate kinase-substr ... | 1990 | 2352326 |
| phosphatidylinositol kinase activity in virus-transformed and nontransformed cells. | we assayed phosphatidylinositol (pi) kinase (ec 2.7.1.67) activity in detergent extracts of nontransformed or virus-transformed cells. nontransformed chicken embryo fibroblasts (cef) contain pi kinase activity with an apparent specific activity of 20 pmol/min per mg of protein. this activity sedimented as a single peak with a molecular weight of approximately 60,000 in a glycerol gradient, although immunoprecipitation with anti-p60src sera showed that the pi kinase activity is distinct from p60c ... | 1985 | 2426580 |
| a major site of tyrosine phosphorylation within the sh2 domain of fujinami sarcoma virus p130gag-fps is not required for protein-tyrosine kinase activity or transforming potential. | phosphorylation of the major autophosphorylation site (tyr-1073) within fujinami sarcoma virus p130gag-fps activates both the intrinsic protein-tyrosine kinase activity and transforming potential of the protein. in this report, a second site of autophosphorylation tyr-836 was identified. this tyrosine residue is found within a noncatalytic domain (sh2) of p130gag-fps that is required for full protein-kinase activity in both rat and chicken cells. autophosphorylation of this tyrosine residue impl ... | 1988 | 2452898 |
| suppression of rous sarcoma virus-induced tumor formation by preinfection with viruses encoding src protein with novel n termini. | two recovered avian sarcoma viruses (rasvs), rasv157 and rasv1702, encode src products which contain novel, nonmyristoylated n-terminal amino acids. these viruses transform chicken embryo fibroblasts and cause tumors in chicks. however, the tumors rasvs induce are small and regress within 2 weeks. to determine whether this regression results from weak tumorigenicity or from the active immunity of the host, we injected 1-week-old chicks with rasv and several days later injected the chicks with ch ... | 1989 | 2542564 |
| increased phosphorylation of tyrosine in vinculin does not occur upon transformation by some avian sarcoma viruses. | the level of phosphotyrosine in vinculin was determined in chicken embryo fibroblasts transformed by various strains of avian sarcoma virus. as previously reported (sefton et al., cell 24:165-174, 1981), vinculin was phosphorylated at tyrosine residues in most cultures examined, but the level varied greatly and no detectable change was found in cultures infected with fujinami sarcoma virus or ur2 sarcoma virus. regardless of the level of vinculin phosphorylation, the number of organized microfil ... | 1985 | 2580230 |
| avian retroviral long terminal repeats bind ccaat/enhancer-binding protein. | dna-protein interactions involving enhancer and promoter sequences within the u3 regions of several avian retroviral long terminal repeats (ltrs) were studied by dnase i footprinting. the rat ccaat/enhancer-binding protein, c/ebp, bound to all four viral ltrs examined. the rous sarcoma virus binding site corresponded closely to the 5' limit of the ltr enhancer; nucleotides -225 to -188 were protected as a pair of adjacent binding domains. the fujinami sarcoma virus ltr bound c/ebp at a single si ... | 1989 | 2725492 |
| localization and footprinting of an enhancer within the avian sarcoma virus gag gene. | a cis-acting regulatory element within the gag gene of avian retroviruses has been localized by deletion analysis, and sites of protein interaction have been studied by dnase i footprinting. unidirectional deletions were made from both the 5' and 3' ends of a 656-base-pair fragment of the gag gene of fujinami sarcoma virus. these deletion mutants were tested for enhancer activity in a chloramphenicol acetyltransferase transient expression assay. a sharp 5' boundary for enhancer activity was obse ... | 1988 | 2833611 |
| construction and biological analysis of deletion mutants of fujinami sarcoma virus: 5'-fps sequence has a role in the transforming activity. | fujinami sarcoma virus (fsv) genome codes for the gag-fps fusion protein fsv-p130. the amino acid sequence of the 3' one-third portion in v-fps is partially homologous to the 3' half of pp60src, or the kinase domain, but the sequence of the 5' portion is unique to v-fps. to identify a possible domain structure in the v-fps sequence responsible for cell transformation, we constructed various deletion mutants of fsv with molecularly cloned viral dna. their transforming activities were assayed by m ... | 1985 | 2991588 |
| defining the borders of the chicken proto-fps gene, a precursor of fujinami sarcoma virus. | the transforming (onc) genes of retroviruses contain specific sequences, derived from as yet poorly defined, normal cellular genes, termed proto-onc genes. proto-onc genes must be defined to explain their docility compared to the oncogenicity of the viral derivatives. here we set out to determine the borders of the chicken proto-fps gene from which the onc genes of avian fujinami (fsv) and prc sarcoma viruses (prcsv) are derived. these onc genes are hybrids of an element from the gag gene of ret ... | 1985 | 2996222 |
| isolation of chicken cellular dna sequences with homology to the region of viral oncogenes that encodes the tyrosine kinase domain. | a library of chicken genomic dna was screened for sequences that could hybridize to a cloned dna fragment containing the transforming gene (v-fps) of fujinami sarcoma virus. in addition to c-fps, two unique chicken cellular dna sequences were isolated that hybridized weakly to v-fps. these sequences hybridized with many other viral oncogenes encoding tyrosine kinases. sequence analysis of the region where homology was detected revealed a region that is highly conserved among the tyrosine kinases ... | 1986 | 3023834 |
| antipeptide antiserum identifies a widely distributed cellular tyrosine kinase related to but distinct from the c-fps/fes-encoded protein. | we raised antibodies directed against a synthetic peptide representing an amino acid sequence of the conserved kinase domain of the transforming protein of fujinami sarcoma virus (fsv) (p140). the antiserum obtained specifically recognized fsv-p140 and its cellular homolog and in addition, it recognized a new cellular protein of 94,000 daltons (ncp94) in avian and mammalian cells. ncp94 was found to be associated with a cyclic nucleotide-independent protein kinase activity that was specific for ... | 1986 | 3023866 |
| cis-acting regulatory elements within gag genes of avian retroviruses. | a cis-acting enhancer element has been detected within the gag gene of several avian retroviruses, including rous sarcoma virus, fujinami sarcoma virus, and the endogenous rous-associated virus-0. a consensus enhancer core sequence, gtggtttg, is present in all of these viral genomes, approximately 900 bases downstream from the site of initiation of transcription. when an internal fragment derived from the gag gene of any of these viruses (spanning nucleotides 533 to approximately 1149) was inser ... | 1987 | 3031470 |
| the structure of the human c-fes/fps proto-oncogene. | we have determined the complete nucleotide sequence of a human dna fragment of approximately 13 kbp, which was shown by southern blot analysis to contain the entire v-fes/fps cellular homolog. the v-fes/fps homologous sequences were dispersed over 11 kbp in 18 interspersed segments which were flanked by splice junctions. fusion of these segments created a dna fragment in which coding regions similar to those observed in the viral oncogenes v-fes of the gardner-arnstein (ga) and snyder-theilen (s ... | 1985 | 4065096 |
| four different classes of retroviruses induce phosphorylation of tyrosines present in similar cellular proteins. | chicken embryo cells transformed by the related avian sarcoma viruses prc ii and fujinami sarcoma virus, or by the unrelated virus y73, contain three phosphoproteins not observed in untransformed cells and increased levels of up to four other phosphoproteins. these same phosphoproteins are present in increased levels in cells transformed by rous sarcoma virus, a virus which is apparently unrelated to the three aforementioned viruses. in all cases, the phosphoproteins contain phosphotyrosine and ... | 1981 | 6086011 |
| cellular localization of the transforming protein of wild-type and temperature-sensitive fujinami sarcoma virus. | fujinami sarcoma virus (fsv) encodes a 140,000-dalton transforming protein, p140, which contains gag- and fps-specific sequences. the cellular localization of this protein was examined by fractionation of [35s]methionine-labeled, fsv-infected chicken embryo fibroblasts. in homogenates of cells infected by wild-type, temperature-resistant fsv prepared in either hypotonic or isotonic buffer, 60 to 80% of the p140 was particulate. isopycnic separation on discontinuous sucrose gradients indicated th ... | 1984 | 6092677 |
| cellular localization of c-fps gene product ncp98. | we compared the intracellular location of the product of the c-fps proto-oncogene, ncp98, with that of its viral homolog p140, the transforming protein of fujinami sarcoma virus. using the technique of biochemical subcellular fractionation, we determined that 60 to 90% of ncp98 and its associated kinase activity are in the soluble fraction of a chicken myeloblast cell line. this fractionation behavior differs from that of p140, which is found predominantly in the particulate fraction, both in fu ... | 1984 | 6092720 |
| src- and fps-containing avian sarcoma viruses transform chicken erythroid cells. | we report here that several oncogene-transducing avian sarcoma virus strains, namely rous sarcoma virus (src), fujinami sarcoma virus (fps), and prcii (fps), transform avian erythroid cells in vitro and in vivo. the src- and fps-transformed erythroblasts grow in vitro for 20-30 generations, require special growth conditions, and tend to differentiate spontaneously. in these properties, they resemble erythroid cells transformed with the erbb-containing h strain of avian erythroblastosis virus (ae ... | 1984 | 6095268 |
| cellular sequences related to three new onc genes of avian sarcoma virus (fps, yes, and ros) and their expression in normal and transformed cells. | two onc genes of avian sarcoma viruses unrelated to the src gene have recently been identified: fps of fujinami sarcoma virus/prcii/ur1 and yes of y73/esh sarcoma virus. in the first part of this study we demonstrated that ur2, the most recently isolated avian sarcoma virus, contains in its genome a unique sequence, ros, nonhomologous to src, fps, and yes sequences or to transforming genes of avian acute leukemia viruses. using cdnas specific to the inserts of avian sarcoma virus genomes, we exa ... | 1982 | 6177868 |
| fujinami sarcoma virus: an avian rna tumor virus with a unique transforming gene. | the oncogenic properties and rna of the fujinami avian sarcoma virus (fsv) and the protein it encodes were investigated and compared to those of other avian tumor viruses with sarcomagenic properties such as rous sarcoma virus and the acute leukemia viruses mc29 and erythroblastosis virus. cloned stocks of fsv caused sarcomas in all chickens inoculated and were found to contain a 4.5-kilobase (kb) and an 8.5-kb rna species. the 4.5-kb rna was identified as the genome of defective fsv because it ... | 1980 | 6246518 |
| characterization of the transforming gene of fujinami sarcoma virus. | the src gene present in all avian sarcoma viruses is not present in the genome of fujinami sarcoma virus, a potent sarcoma-inducing virus in chickens. fujinami virus is defective and requires helper virus for replication. rna from a mixture of helper and transforming viruses consists of two components, 35s and 28s. oligonucleotide fingerprinting of each rna component revealed that the 35s component was identical to the rna of the helper virus. thus, the genome of fujinami virus must be the 28s r ... | 1980 | 6248881 |
| homology exists among the transforming sequences of avian and feline sarcoma viruses. | fujinami sarcoma virus (fsv) of chickens does not contain nucleotide sequences related to the src gene of rous sarcoma virus, but it carries unique sequences of at least 3000 bases, which are likely to code for the transforming protein of this virus. using radioactive dna complementary to fsv-unique sequences, we investigated the relatedness of fsv to other sarcoma-leukemia retroviruses in vertebrates. under conditions of moderate stringency, no cross-hybridization was detected between fsv cdna ... | 1980 | 6256742 |
| transforming proteins of some feline and avian sarcoma viruses are related structurally and functionally. | transformation of chicken cells by fujinami sarcoma virus (fsv), prc ii or y73 (three independently isolated avian sarcoma viruses that are replication-defective and lack the rous sarcoma virus src gene) resulted in significant elevation (4-13 fold) of phosphotyrosine levels in cellular protein. the gag-related proteins encoded by these avian sarcoma viruses (asvs) were all associated with tyrosine-specific protein kinase activity when assayed in immune complexes and were phosphorylated at both ... | 1981 | 6263483 |
| molecular cloning of the fujinami sarcoma virus genome and its comparison with sequences of other related transforming viruses. | full-length proviral dna of fujinami sarcoma virus (fsv) of chickens was molecularly cloned and characterized. an analysis of fsv dna integrated in mammalian cells showed that restriction endonuclease saci has a single cleavage site on fsv dna. unintegrated closed circular fsv dna obtained from newly infected cells was linearized by digestion with saci and cloned into lambdagtwes.lambdab. the following three different molecules were isolated: fsv-1 (4.4 kilobases [kb]) and fsv-2 (4.7 kb), which ... | 1982 | 6284986 |
| isolation of 16l virus: a rapidly transforming sarcoma virus from an avian leukosis virus-induced sarcoma. | we have isolated a replication-defective rapidly transforming sarcoma virus (designated 16l virus) from a fibro-sarcoma in a chicken infected with td107a, a transformation-defective deletion mutant of subgroup a schmidt-ruppin rous sarcoma virus. 16l virus transforms fibroblasts and causes sarcomas in infected chickens within 2 wk. its genomic rna is 6.0 kilobases and contains sequences homologous to the transforming gene (fps) of fujinami sarcoma virus (fsv). rnase t1 oligonucleotide analysis s ... | 1982 | 6289331 |
| dna clone of avian fujinami sarcoma virus with temperature-sensitive transforming function in mammalian cells. | we have molecularly cloned an integrated proviral dna of fujinami sarcoma virus (fsv) into a lambda phage vector and further subcloned it into plasmid pbr322. the source of provirus was a quail nonproducer cell clone transformed by fsv. the fsv strain used is temperature sensitive in the maintenance of transformation of avian cells. the recombinant plasmid was shown to contain an entire fsv genome by fingerprinting the hybrids formed with 32p-labeled fsv rna. this analysis also revealed a previo ... | 1982 | 6292501 |
| structural relationship between the chicken dna locus, proto-fps, and the transforming gene of fujinami sarcoma virus, delta gag-fps. | the avian fujinami sarcoma virus (fsv) contains a hybrid transforming gene (delta gag-fps) with a 5' 1.3-kb portion derived from the gag gene of avian retroviruses and a 3' 2.8-kb portion (fps) derived from a cellular prototype. a lambda recombinant dna clone carrying fps sequences within a 16-kb insert of cellular dna, termed lambda proto-fps clone 12, has been selected from a chicken dna library for comparison with the viral onc gene. mapping of endonuclease-resistant proto-fps dna fragments a ... | 1983 | 6310887 |
| a fps gene without gag gene sequences transforms cells in culture and induces tumors in chickens. | from molecularly cloned dnas of fujinami sarcoma virus (fsv) and the schmidt-ruppin-a strain of rous sarcoma virus (sra), viral dna was constructed in which fps-specific sequences encoded in fsv replaced the src gene of sra. a 3' fragment of fsv dna, from an atg methionine coding sequence 148 base pairs downstream from the gag-fps junction through the long terminal repeat, was joined to cloned sra dna at the translation start site for the src gene. the resultant dna clone contained the splice ac ... | 1983 | 6605429 |
| synthetic peptide fragment of src gene product inhibits the src protein kinase and crossreacts immunologically with avian onc kinases and cellular phosphoproteins. | all the known avian sarcoma viruses have associated protein kinase activities that phosphorylate tyrosine residues of their target proteins. a decapeptide fragment of pp60src of rous sarcoma virus (rsv), residues 415-424, and an analog of that sequence have been chemically synthesized by solid-phase methods. the two decapeptides were not phosphorylated by pp60src of rsv, p90 of y73 avian sarcoma virus, or p140 of fujinami sarcoma virus. however, both peptides were able to inhibit competitively t ... | 1981 | 6801651 |
| a cellular protein is immunologically crossreactive with and functionally homologous to the fujinami sarcoma virus transforming protein. | we obtained a regressing-tumor antiserum specific for the unique sequence of the transforming protein p140 of fujinami sarcoma virus by injecting fischer rats with syngeneic embryo cells transformed with fujinami sarcoma virus. this serum is capable of immunoprecipitating a protein of 98,000 daltons from cell extracts of normal, uninfected chicken bone marrow cells. this normal cellular protein (ncp98) was shown to be structurally related to p140, sharing the majority of 35s-methionine-labeled t ... | 1982 | 7094017 |