| possible mechanism by which stress accelerates growth of virally derived tumors. | stress accelerates the growth of certain types of tumors. here we report a possible metabolic mechanism underlying this phenomenon. some early features of transformation include increased number of glucose transporters and greatly enhanced rates of glucose uptake; this adaptation accommodates the vast energy demands needed for neoplastic growth. in contrast, glucocorticoids, a class of steroid hormones secreted during stress, inhibit glucose transport in various tissues; this is one route by whi ... | 1992 | 1438318 |
| evidence that a g-protein transduces signals initiated by the protein-tyrosine kinase v-fps. | the protein-tyrosine kinase (ptk) v-fps induces protein kinase c (pkc)-dependent expression of the transformation-related 9e3 gene in chicken embryo fibroblasts (spangler, r., joseph, c., qureshi, s.a., berg, k., and foster, d.a. (1989) proc. natl. acad. sci. u.s.a. 86, 7017-7021). we present evidence here that a gtp-binding protein (g-protein) is a component of this pkc-dependent signaling pathway. 1) a gtp analogue that stimulates g-protein-mediated signals induced 9e3 gene expression. 2) a gd ... | 1991 | 1714894 |
| catalytic and non-catalytic domains of the fujinami sarcoma virus p130gag-fps protein-tyrosine kinase distinguished by the expression of v-fps polypeptides in escherichia coli. | while protein-tyrosine kinases share a region of sequence identity corresponding to their kinase domains, the specific elements essential for catalysis, substrate binding and substrate specificity are largely undefined. the p130gag-fps transforming protein of fujinami avian sarcoma virus is a cytoplasmic tyrosine kinase with a complex structure that includes a c-terminal kinase domain. to identify the precise n-terminal border of the v-fps catalytic region and to assess its interactions with non ... | 1987 | 2449646 |
| 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 |
| a retrovirus encoding the v-fps protein-tyrosine kinase induces factor-independent growth and tumorigenicity in fdc-p1 cells. | there is increasing evidence that protein-tyrosine kinases play pivotal roles in the response to growth-factor signals. the cytoplasmic tyrosine kinase c-fps/fes, due to its restricted expression in hematopoietic tissue, is likely to participate in hematopoietic growth-factor signalling. we have introduced a retrovirus containing an activated fps gene (encoding p130gag-fps) into the growth factor-dependent myeloid cell line fdc-p1. clonal cell lines were derived by selection for a marker gene co ... | 1992 | 1390902 |
| 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 |
| the induction of egr-1 expression by v-fps is via a protein kinase c-independent intracellular signal that is sequentially dependent upon haras and raf-1. | activating the protein-tyrosine kinase activity of v-fps leads to the rapid transcriptional activation of the egr-1 gene, which encodes a mitogen-responsive transcription factor. activation of egr-1 by v-fps was insensitive to protein kinase c depletion, suggesting that a protein kinase c-independent signal activated by v-fps leads to the induction of egr-1. expression of v-fps in transient expression assays induced egr-1 promoter activation. v-haras and v-raf also activated the egr-1 promoter. ... | 1992 | 1332742 |
| 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 |
| isolation and characterization of cdnas from bamhi-h gene family rnas associated with the tumorigenicity of marek's disease virus. | it has been reported that loss of the tumorigenic potential of attenuated marek's disease virus (mdv) is strongly associated with amplification of the 132-bp repeat sequences found within the bamhi-d and bamhi-h fragments contained within the long terminal repeat and the long internal repeat, respectively. the expansion of this region results in loss of transcripts that are 3.8, 3.0, and 1.8 kbp long that are produced by tumorigenic strains of mdv. this evidence suggests that production of one o ... | 1992 | 1279201 |
| 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 |
| investigation of the role of p130gag-fps in transformation: generation and use of a temperature-sensitive mutant p130gag-fps. | changing glu-1025 to asp in fujinami sarcoma virus p130gag-fps made the protein temperature sensitive for transformation and protein-tyrosine kinase activity. another mutant, phe-1073 p130gag-fps, lacking the major autophosphorylation site, has an extended latent period for transformation (g. a. weinmaster, m. j. zoller, m. smith, e. hinze, and t. pawson, cell 37:559-568, 1984). by introducing the asp-1025 lesion into phe-1073 p130gag-fps, we showed that this mutant protein is required for the m ... | 1988 | 2843679 |
| pp60c-src has less affinity for the detergent-insoluble cellular matrix than do pp60v-src and other viral protein-tyrosine kinases. | a difference in affinity for a nonidet p-40-insoluble cellular matrix was observed between the products of the viral and cellular src genes. it has previously been demonstrated that pp60v-src is associated with a detergent-insoluble matrix containing the cellular cytoskeleton (j. g. burr, g. dreyfuss, s. penman, and j. m. buchanan, proc. natl. acad. sci. usa 77:3484-3488, 1980). we observed a similar association of the transforming proteins of fujinami sarcoma virus (p130gag-fps) and yamaguchi 7 ... | 1987 | 2439705 |
| specific inhibition of tyrosine kinase activity by an antibody to the v-ros oncogene product. | antibodies present in two peritoneal exudates of rats bearing abdominal tumors induced by ur2-transformed rat cells were characterized. the ability to immunoprecipitate p68gag-ros and to inhibit the protein and phospholipid kinase activities of this protein was investigated. one of the exudates specifically inhibited tyrosyl phosphorylation by p68gag-ros but not the activity of other known tyrosyl kinases, such as p150gag-fps of ur1 avian sarcoma virus, p60src, and the insulin receptor. it preci ... | 1986 | 2430110 |
| characterization of the monomeric and complex-associated forms of the gag-onc fusion proteins of three isolates of feline sarcoma virus: phosphorylation, kinase activity, acylation, and kinetics of complex formation. | the gag-onc fusion proteins of three isolates of feline sarcoma virus (st-fesv, ga-fesv, tp1-fesv) from a stable noncovalent complex with two cellular phosphoproteins, pp90 and pp50. these two phosphoproteins are the same phosphoproteins which have been shown to complex with the transforming proteins of rous sarcoma virus, fujinami sarcoma virus, yamaguchi 73 virus (lipsich et al., 1982), and prcii avian sarcoma virus (adkins et al., 1982). both the monomeric and complex-associated gag-onc fusio ... | 1986 | 2422812 |
| direct identification of phosphotyrosine-containing proteins in some retrovirus-transformed cells by use of anti-phosphotyrosine antibody. | for direct identification of phosphotyrosine-containing proteins in lysates of various cells, phosphotyrosine (p-tyr) was coupled to carrier proteins and anti-p-tyr antibodies were raised in rabbits and mice. the antibodies were highly specific for p-tyr and did not cross-react with phosphoserine or phosphothreonine. the mean association constant of rabbit anti-p-tyr antibody to n-acetyl-p-tyr was about four times that of rabbit anti-azobenzene phosphonate antibody. in addition, anti-p-tyr antib ... | 1986 | 2416436 |
| 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 |
| a glycoprotein in the plasma membrane matrix as a major potential substrate of p60v-src. | a potential substrate of p60v-src in rous sarcoma virus-transformed cells was found to be a 130-kilodalton (kda) glycoprotein which binds to lectin-sepharose and can be immunoprecipitated by an anti-phosphotyrosine antibody. this glycoprotein was shown to be distinct from the fibronectin receptor and a cellular protein phosphorylated in p60v-src immune complexes. the protein was a transmembrane protein localized in the plasma membrane and resistant to extraction with triton x-100. the 130-kda pr ... | 1990 | 2153925 |
| 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 |
| the ras-related gene rhob is an immediate-early gene inducible by v-fps, epidermal growth factor, and platelet-derived growth factor in rat fibroblasts. | a set of genes is rapidly inducible when quiescent fibroblasts are stimulated by growth factors or by the activation of temperature-sensitive retroviral protein-tyrosine kinases. most of these so-called immediate-early genes were cloned by differential cdna hybridization. dna sequence analysis identified many of them as putative members of the growth factor or of the transcription factor gene family, suggesting a role in signal transmission during the g0-to-g1 transition. in this study, we ident ... | 1991 | 1710770 |
| correspondence between immunological and functional domains in the transforming protein of fujinami sarcoma virus. | monoclonal antibodies reactive with either gag or fps portions of the wild-type fujinami sarcoma virus transforming protein have been used to probe the structure of proteins encoded by mutant genomes constructed in vitro. the pattern of immunoreactivity suggests that the functional domain defined in genetic studies (stone et al., cell 37:549-558, 1984) corresponds to a discrete immunological domain in the native, wild-type fujinami sarcoma virus protein. at least one mutation affecting both the ... | 1985 | 2991592 |
| a pyruvate-stimulated adenylate cyclase has a sequence related to the fes/fps oncogenes and to eukaryotic cyclases. | the pyruvate-stimulated adenylate cyclase from brevibacterium liquefaciens produces up to 450 microm cyclic amp in the culture medium when the bacterium is grown on glucose and alanine. in this paper we report the cloning, expression and sequencing of the gene for this enzyme. residues were identified, within the c-terminal domain, which are conserved in adenylate and guanylate cyclase sequences from eukaryotes and in the adenylate cyclase of the prokaryote rhizobium meliloti. we have also ident ... | 1991 | 1683468 |
| inducibility of neoplastic transformation by fujinami sarcoma virus in an in vitro chick embryo model for osteosarcoma: (i) effect of differentiation and (ii) investigation for in vivo growth potential in athymic mice. | we have described previously a novel in vitro model for the study of osteosarcoma. in this system, chick periosteal explants (cep) transformed by the p140gag-fps oncoprotein of fujinami avian sarcoma virus (fsv) exhibit biochemical and histological manifestations characteristic of osteosarcoma. in the present study, a hypothesis suggesting that more differentiated bone cells may resist fsv-induced oncogene changes was tested. in one set of experiments, cep cultures were pretreated with a high do ... | 1991 | 1664227 |
| v-fps-responsiveness in the egr-1 promoter is mediated by serum response elements. | egr-1, a mitogen-responsive transcription factor, is rapidly induced by v-fps in the absence of protein synthesis. thus, egr-1 is a primary response to the protein-tyrosine kinase activity of v-fps. to determine the v-fps-responsive elements in the egr-1 promoter, deletion mutants of the egr-1 promoter were used in transient expression assays. a v-fps expression vector was contransfected into nih 3t3 cells with chloramphenicol acetyl transferase (cat) gene expression vectors under the control of ... | 1992 | 1594452 |
| effects of transformation by v-fps on nucleoside transport in rat-2 fibroblasts. | important cellular nutrients, including nucleosides and hexose sugars, are rapidly taken up by cells, largely through mediated carrier systems. the present study examined nucleoside and hexose transport activity in normal rat-2 fibroblasts and clonal derivatives that expressed either the wild-type (c10) or a temperature-sensitive mutant (na9) form of v-fps, a transforming protein-tyrosine kinase. initial uptake rates (transport) of adenosine, thymidine, 3-o-methylglucose and 2-deoxyglucose were ... | 1992 | 1540128 |
| 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 |
| mutational analysis of a phosphotransfer motif essential for v-fps tyrosine kinase activity. | the catalytic domains of protein-tyrosine kinases such as the p130gag-fps oncoprotein contain the sequence hrdlaarn, followed thirteen residues c-terminal by dfg (p130gag-fps residues 1041-1048 and 1061-1063). these residues define a structural motif conserved among eucaryotic protein kinases (-rd----n, dfg) and shared with several procaryotic 3'aminoglycoside phosphotransferases (h-d----n, d-g). functional analysis of mutant v-fps proteins employing bacterial and mammalian expression systems in ... | 1988 | 2577868 |
| lymphoid and mesenchymal tumors in transgenic mice expressing the v-fps protein-tyrosine kinase. | src, abl, and fps/fes are prototypes for a family of genes encoding nonreceptor protein-tyrosine kinases. the oncogenic potential of the v-fps protein-tyrosine kinase was investigated by introduction of the gag-fps coding sequence of fujinami sarcoma virus into the mouse germ line. transgenic mice with v-fps under the transcriptional control of a 5' human beta-globin promoter (gf) or with both 5' and 3' beta-globin regulatory sequences (gef) were viable. unexpectedly, both gf and gef transgenes ... | 1989 | 2555699 |
| 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 |
| localization of major potential substrates of p60v-src kinase in the plasma membrane matrix fraction. | subcellular localization of potential substrates of a tyrosine-protein kinase, p60v-src, was analyzed by cell fractionation in combination with immunoblotting with antiphosphotyrosine antibody. in cells transformed by wild type rous sarcoma virus, most phosphotyrosine-containing proteins were found both in plasma membranes and in a cytoplasmic matrix structure associated with plasma membranes and resistant to nonionic detergent extraction (plasma membrane matrix). a similar localization of phosp ... | 1989 | 2497423 |
| novel protein-tyrosine kinase cdnas related to fps/fes and eph cloned using anti-phosphotyrosine antibody. | a rat brain lambda gt11 cdna expression library was screened with anti-phosphotyrosine antibody to identify recombinant clones that encode enzymatically active protein-tyrosine kinases. the inserts of two bacteriophage that gave positive signals were sequenced. both translation products possess sequence motifs characteristic of protein-tyrosine kinases. however, each polypeptide is distinct from previously described members of the tyrosine kinase family. the predicted product of the lambda b1 cl ... | 1988 | 2485255 |
| dexamethasone effects on induction of neoplastic transformation by fujinami sarcoma virus in an in vitro chick embryo periosteal model for osteosarcoma. | recently we have developed a model in vitro system for the study of factors regulating the histogenesis of osteosarcoma. in this system, fujinami sarcoma virus (fsv) induces osteosarcomatous changes such as increased cell proliferation and altered patterns of bone and nonmineralized matrix (osteoid) formation. such changes can be quantitated at the individual cell level, by computer-assisted morphometry. here we report on the effects of dexamethasone (dex) on fsv-induced neoplastic transformatio ... | 1988 | 2847866 |
| single amino acid substitution, from glu1025 to asp, of the fps oncogenic protein causes temperature sensitivity in transformation and kinase activity. | we have sequenced 2.7 kilobases of v-fps dna encoding the transforming protein, p140, of the temperature-sensitive (ts) fl-15 clone of avian fujinami sarcoma virus. ten single nucleotide differences were found when compared with the v-fps sequence of the temperature-resistant (tr) clone, fsv-2. of these differences, five encoded altered amino acids within the 5' fps domain, only one encoded an altered amino acid in the 3' kinase domain, and four were silent. among the five amino acid changes in ... | 1986 | 2877522 |
| 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 |
| avian sarcoma virus gag-fps and gag-yes transforming proteins are not myristylated or palmitylated. | the transforming proteins of several avian sarcoma viruses were examined for evidence of covalently attached fatty acids. while the product of the viral src gene could be readily labeled biosynthetically with [3h]myristic acid, the gag-onc transforming proteins of fujinami sarcoma virus, prcii, prciip, and y73 avian sarcoma viruses were not readily labeled with either [3h]myristate or [3h]palmitate. thus, avian gag-onc proteins appear to lack modifications shared by mammalian gag and gag-onc pro ... | 1986 | 3491459 |
| progressive cardiac fibrosis and myocyte injury in v-fps transgenic mice. a model for primary disorders of connective tissue in the heart? | transgenic mice that express v-fps protein-tyrosine kinase have severe cardiac or neurologic abnormalities and a high incidence of lymphoid or mesenchymal tumors. the cardiac lesions of v-fps transgenic mice were examined at less than 1, 2, 3, 6, 14, 26, and 43 weeks of age (total n = 19) and compared with nontransgenic littermate controls (n = 34). three of eight transgenic animals 1 to 4 days old showed moderate proliferation of connective tissue elements most evident along the septal endocard ... | 1991 | 2016851 |
| construction and expression of linker insertion and site-directed mutants of v-fps protein-tyrosine kinase. | | 1991 | 1659662 |
| an n-terminal peptide from p60src can direct myristylation and plasma membrane localization when fused to heterologous proteins. | the src gene product, p60src, of rous sarcoma virus (rsv) is a tyrosine-specific protein kinase which is associated with the plasma membrane of infected cells. myristic acid is bound in an amide linkage to glycine 2 of p60src. of the n-terminal 30 kilodaltons of p60src, only amino acids 1-14 are required for myristylation, and myristylation of p60src may be required for its membrane association, and for cell transformation. to test the hypothesis that the first 14 amino acids of p60src contain a ... | 1985 | 3920530 |
| the myristylation signal of p60v-src functionally complements the n-terminal fps-specific region of p130gag-fps. | the p130gag-fps protein-tyrosine kinase of fujinami sarcoma virus contains an n-terminal fps-specific domain (nfps) that is important for oncogenicity. the n-terminal 14 amino acids of p60v-src, which direct myristylation and membrane association, can replace the gag-nfps sequences of p130gag-fps (residues 1 to 635), producing a highly transforming src-fps polypeptide. conversely, gag-nfps can restore modest transforming activity to a nonmyristylated v-src polypeptide. these results emphasize th ... | 1989 | 2747647 |
| a simple method for immunoaffinity purification of nondenatured avian sarcoma and leukemia virus gag-containing proteins. | we have developed a one-step purification procedure for proteins containing the n-terminal portion of the gag protein of avian sarcoma and leukemia viruses. in this procedure, a resin with a covalently attached monoclonal antibody to the gag protein p19 is used to bind gag-containing proteins from crude extracts. after washing of the resin, the bound proteins are eluted with 2 m mgcl2. for the transforming protein kinase encoded by fujinami sarcoma virus p130gag-fps, this procedure gave an enric ... | 1987 | 2821689 |
| in vitro transformation of osteoblasts: putative formation of osteosarcoma in vitro. | the study of bone cancer has been difficult in part due to a lack of appropriate in vitro osteosarcoma model systems. the development of such systems is essential if a clearer understanding of the biology of and mechanisms behind the formation and progression of bone cancers is to be obtained. we report here the development of an in vitro model system which demonstrates important characteristics generally associated with osteosarcoma. the chick periosteal osteogenesis model was infected with the ... | 1987 | 2827712 |
| a noncatalytic domain conserved among cytoplasmic protein-tyrosine kinases modifies the kinase function and transforming activity of fujinami sarcoma virus p130gag-fps. | proteins encoded by oncogenes such as v-fps/fes, v-src, v-yes, v-abl, and v-fgr are cytoplasmic protein tyrosine kinases which, unlike transmembrane receptors, are localized to the inside of the cell. these proteins possess two contiguous regions of sequence identity: a c-terminal catalytic domain of 260 residues with homology to other tyrosine-specific and serine-threonine-specific protein kinases, and a unique domain of approximately 100 residues which is located n terminal to the kinase regio ... | 1986 | 3025655 |
| [phosphotyrosine]protein phosphatase in rat brain. a major [phosphotyrosine]protein phosphatase is a 23 kda protein distinct from acid phosphatase. | a [phosphotyrosine]protein phosphatase (ptppase) was purified almost to homogeneity from rat brain, with [32p]p130gag-fps, an oncogene product of fujinami sarcoma virus, as substrate. the characteristics of the purified preparation of ptppase were as follows: the enzyme was a monomer with a molecular mass of 23 kda; its optimum ph was 5.0-5.5; its activity was not dependent on bivalent cations; its activity was strongly inhibited by sodium vanadate, but was not inhibited by zncl2, l(+)-tartrate ... | 1986 | 3026366 |
| transformation of rat fibroblasts by fsv rapidly increases glucose transporter gene transcription. | elevation of glucose transport is an alteration common to most virally induced tumors. rat fibroblasts transformed with wild-type or a temperature-sensitive fujinami sarcoma virus (fsv) were studied in order to determine the mechanisms underlying the increased transport. five- to tenfold increases in total cellular glucose transporter protein in response to transformation were accompanied by similar increases in transporter messenger rna levels. this, in turn, was preceded by an absolute increas ... | 1987 | 3029870 |
| 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 |
| transcriptional activity of avian retroviral long terminal repeats directly correlates with enhancer activity. | retroviral long terminal repeats (ltrs) contain elements responsible for the control of proviral transcription and gene expression. molecular clones of the ltr region of a number of avian retroviruses have been isolated, and dna sequence analysis of these clones reveals the existence of a related, but heterogeneous, family of ltrs. to examine the functional significance of the observed sequence differences, we have directly tested the abilities of several different avian retrovirus ltrs to act a ... | 1985 | 2982034 |
| distinctive effects of the viral oncogenes myc, erb, fps, and src on the differentiation program of quail myogenic cells. | the relationship between susceptibility to transformation in vitro by different oncogenes and terminal differentiation was analyzed in embryonic quail myogenic cells. infection with rous sarcoma virus (rsv), fujinami sarcoma virus (fsv), avian erythroblastosis virus (aev), and the avian myelocytomatosis virus mc29 led to rapid and massive transformation. transformed cells had distinctive morphological alterations, increased proliferation rates, and the ability to grow in agar suspension. further ... | 1985 | 2982156 |
| no expression of a rous sarcoma virus-induced tumor antigen in mammalian cells infected with retroviruses transducing other oncogenes of the src gene family. | immunization with mouse and rat cells transformed by rous sarcoma virus (rsv) or by b77 avian sarcoma virus (asv) induced complete transplantation resistance against an rsv-induced mouse tumor (csa1m) in syngeneic hosts. in contrast, most of the mice immunized with a fujinami sarcoma virus-transformed rat fibroblast line (fsv-3y1), a feline sarcoma virus-transformed cat fibroblast line (fesv-fef), an abelson leukemia virus-infected balb/3t3 cell line (ablv-3t3), or an uninfected 3y1 cell line co ... | 1985 | 2985859 |
| specific expression of the human cellular fps/fes-encoded protein ncp92 in normal and leukemic myeloid cells. | we have found that both an antibody directed against a synthetic peptide representing an amino acid sequence of the conserved kinase domain of transforming protein p140 of fujinami sarcoma virus and a regressing tumor antiserum recognized the products of the c-fps/fes genes of both avian and mammalian cells. the anti-peptide antibody also recognized a 94-kilodalton protein that was related to but distinct from the c-fps/fes product in structure and in tissue distribution. a 92-kilodalton protein ... | 1985 | 2986115 |
| 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 |
| specific transforming potential of oncogenes encoding protein-tyrosine kinases. | several chimeric murine retroviruses were constructed to test whether the gag sequence of abelson murine leukemia virus (a-mulv) could influence the in vitro specificity of two sarcoma-inducing oncogenes: src of rous sarcoma virus and fps of fujinami sarcoma virus. although the src- or fps- containing chimerae could transform fibroblasts, they were unable to mimic the action of a-mulv in causing lymphoid transformation in vitro. a-mulv-derived gag sequences could, however, functionally replace t ... | 1985 | 2992940 |
| 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 |
| a lysine in the atp-binding site of p130gag-fps is essential for protein-tyrosine kinase activity. | the p130gag-fps transforming protein of fujinami sarcoma virus (fsv) possesses tyrosine-specific protein kinase activity and autophosphorylates at tyr-1073. within the kinase domain of p130gag-fps is a putative atp-binding site containing a lysine (lys-950) homologous to lysine residues in camp-dependent protein kinase and p60v-src which bind the atp analogue p-fluorosulfonylbenzoyl-5' adenosine. fsv mutants in which the codon for lys-950 has been changed to codons for arginine or glycine encode ... | 1986 | 3007119 |
| 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 |
| neoplastic transformation of osteogenic cells: quantitative morphometric analysis of an in vitro model for osteosarcoma. | previously we have reported the development of a model in vitro system for the study of osteosarcoma. in this system, when chick periosteal explants are infected with fujinami sarcoma virus (fsv), osteosarcoma-like tissue is formed. in the present study, a series of histopathologic parameters of neoplastic transformation and osteogenesis were quantitated, at a single cell level, by computer-assisted morphometry. most significantly, it was found that compared to uninfected (control) cultures, in ... | 1988 | 2844430 |
| 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 |
| 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 |
| cleavage of four avian sarcoma virus polyproteins with virion protease p15 removes gag sequences and yields large fragments that function as tyrosine phosphoacceptors in vitro. | the transformation-specific polyproteins of avian sarcoma viruses prcii, prcii-p, fujinami sarcoma virus (fsv), and esh sarcoma virus (esv) consist of two domains, one derived from a partial viral gag gene and the other representing an apparently cell-derived insert in the defective viral genome. these gag-linked proteins were cleaved with retrovirion protease p15. cleavage of prcii-p polyprotein p170, p105 of prcii, and p140 of fsv occurred within the gag domain and generated fragments of mr 13 ... | 1981 | 6170987 |
| concomitant enhancement of a cytoskeleton-associated 76,000-dalton protein and inhibition of fluid-phase pinocytosis by interferon-alpha in fujinami sarcoma virus-transformed rat 3y1 cells. | addition of rat interferon-alpha (ifn-alpha) to fujinami sarcoma virus-transformed rat 3y1 cells progressively inhibited fluid-phase pinocytosis [10% inhibition at 3 h; maximal (60%) inhibition by 12 h]. electrophoretic analysis of the cytoskeletal fraction from cultures exposed to ifn for 24 h revealed a novel 76,000-dalton protein (ckp76). the kinetics of its appearance paralleled the inhibition of fluid-phase pinocytosis. ckp76 was not detected in cultures pretreated with actinomycin d, or pr ... | 1986 | 3027204 |
| 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 |
| avian sarcoma virus ur2 encodes a transforming protein which is associated with a unique protein kinase activity. | ur2 is a newly characterized avian sarcoma virus whose genome contains a unique sequence that is not related to the sequences of other avian sarcoma virus transforming genes thus far identified. this unique sequence, termed ros, is fused to part of the viral gag gene. the product of the fused gag-ros gene of ur2 is a protein of 68,000 daltons (p68) immunoprecipitable by antiserum against viral gag proteins. in vitro translation of viral rna and in vivo pulse-chase experiments showed that p68 is ... | 1982 | 6177870 |
| enzymatic activation of fujinami sarcoma virus gag-fps transforming proteins by autophosphorylation at tyrosine. | site-directed mutagenesis of the fujinami sarcoma virus (fsv) genome has suggested that tyr 1073 of the p130gag--fps protein-tyrosine kinase is a regulatory site. to investigate directly the ability of tyrosine phosphorylation to affect p130gag--fps kinase activity, the phosphotyrosyl phosphatase inhibitor orthovanadate and partially purified phosphotyrosyl phosphatases were used to manipulate the stoichiometry of p130gag--fps phosphorylation. phosphorylation of p130gag--fps at tyr 1073 correlat ... | 1987 | 3034604 |
| the rat facilitated glucose transporter gene. transformation and serum-stimulated transcription initiate from identical sites. | the gene encoding the rat brain facilitated glucose transporter protein was cloned and partially sequenced. the transcribed regions encode 10 exons that span about 30 kilobases of genomic dna. the intron size is markedly biased, the first two significantly greater in length than the seven others. all of the introns are predicted to occur in regions that encode putative extramembranous domains of the protein, consistent with the proposed topology of 12 alpha-helical membrane-spanning segments. in ... | 1988 | 3198639 |
| 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 |
| modifications of tumor histology by point mutations in the v-fps oncogene: possible role of extracellular matrix. | fujinami sarcoma virus (fsv) encodes a protein-tyrosine kinase, p130gag-fps, whose enzymatic activity and ability to transform cultured cells to a neoplastic phenotype are reduced by substitution of the major autophosphorylation site tyrosine-1073 with other amino acids. we compared the histopathology of tumors formed in syngeneic immunocompetent rats by rat-2 cells and by rat-2 cells transformed in culture with (a) wild type (wt) fsv, (b) mutant fsv where the codon for tyrosine-1073 of p130gag- ... | 1987 | 3315185 |
| protein kinase activity of fsv (fujinami sarcoma virus) p130gag-fps shows a strict specificity for tyrosine residues. | a number of oncogenic viruses encode transforming proteins with protein kinase activities apparently specific for tyrosine residues. recent evidence has raised questions as to the substrate specificity of these kinases in general and the physiological relevance of tyrosine phosphorylation in particular. the p130gag-fps transforming protein of fujinami sarcoma virus (fsv) is strongly phosphorylated at 2 tyrosine residues in fsv-transformed cells of which 1 (tyr-1073) is also the major site of p13 ... | 1986 | 3510199 |
| nucleotide sequences of feline retroviral oncogenes (v-fes) provide evidence for a family of tyrosine-specific protein kinase genes. | the nucleotide sequences encoding the transforming polyproteins of the snyder-theilen and gardner-arnstein strains of feline sarcoma virus (fesv) have been determined. these sequences include a viral transforming gene (v-fes), derived from cellular proto-oncogene sequences (c-fes) of domestic cats by recombination with feline leukemia virus (felv). the v-fes sequences are predicted to encode a polypeptide domain strikingly similar to that specified by the transforming gene (v-fps) of the avian f ... | 1982 | 6183005 |
| localization and characterization of phosphorylation sites of the fujinami avian sarcoma virus and prcii virus transforming proteins. | 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 ... | 1982 | 6190824 |
| transforming genes of avian (v-fps) and mammalian (v-fes) retroviruses correspond to a common cellular locus. | the gardner (ga) and snyder-theilen (st) isolates of feline sarcoma virus (fesv) represent genetic recombinants between feline leukemia virus (felv) and transformation-specific sequences (v-fes gene) of cat cellular origin. a related transforming gene (v-fps), common to the fujinami, prc ii, and ur 1 strains of avian sarcoma virus has also been described. translational products of each of these recombinant virus isolates are expressed in the form of polyproteins exhibiting protein kinase activit ... | 1983 | 6301150 |
| isolation of tyrosine-o-sulfate by pronase hydrolysis from fibronectin secreted by fujinami sarcoma virus-infected rat fibroblasts. | in a recent paper, we reported the loss of large amounts of protein-bound tyrosine sulfate after infection of rat fibroblasts by avian sarcoma viruses. the analogy to the reported loss of surface fibronectin on malignant transformation, which contained sulfate of unknown location, called our attention to this compound. in a previous paper, we briefly reported on isolation from the supernatant fraction of rat fibroblasts infected by fujinami sarcoma virus fibronectin that yielded tyrosine-o-sulfa ... | 1985 | 3855547 |
| 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 |
| 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 |
| 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 |
| revertants and partial transformants of rat fibroblasts infected with fujinami sarcoma virus. | fifteen revertants were isolated from three independent clones of rat fibroblasts transformed by fujinami sarcoma virus (fsv). three revertant clones resulted from the deletion of the one copy of the fsv provirus, and one encoded an enzymatically inactive, transformation-defective protein. the remaining revertant clones were characterized by a transcriptional block of the provirus. digestion of chromosomal dna with mspi and hpaii revealed that the fsv provirus was hypermethylated in these revert ... | 1984 | 6323733 |
| 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 |
| temperature-sensitive mutants of fujinami sarcoma virus: tumorigenicity and reversible phosphorylation of the transforming p140 protein. | several clones of fujinami sarcoma virus (fsv) isolated from a laboratory stock or from mutagenized virus were temperature sensitive (ts) in transformation of cells in culture. when shifted from the permissive (37 degrees c) to the nonpermissive (41.5 degrees c) temperature, the cellular phenotype reverted to normal within 2 h, but it required about 48 h at 37 degrees c to revert back to the transformed morphology. a temperature-resistant (tr) fsv clone was isolated from a tumor of an animal. al ... | 1981 | 6264151 |
| a third class of avian sarcoma viruses, defined by related transformation-specific proteins of yamaguchi 73 and esh sarcoma viruses. | the gag-linked transformation-specific protein (polyprotein) p80 of esh avian sarcoma virus (esv) has been compared by tryptic peptide mapping with the homologous protein p90 of yamaguchi 73 avian sarcoma virus (y73). p80 of esv and p90 of y73 were found to share all four of their major nonstructural, transformation-specific, methionine-containing peptides and to have at least seven cysteine-containing transformation-specific peptides in common. two nonstructural cysteine-containing peptides uni ... | 1981 | 6264485 |
| evidence that there exist four classes of rna tumor viruses which encode proteins with associated tyrosine protein kinase activities. | the transforming protein of rous sarcoma virus, p60src, the abelson virus protein, p120, and the y73 virus protein, p90, all have associated tyrosine protein kinase activities in vitro. possible structural homology between these functionally related proteins was investigated by two-dimensional analysis of both methionine-containing and phosphate-containing tryptic peptides derived from biosynthetically labeled proteins. marked differences were found between the maps of both [35s]methionine-label ... | 1981 | 6268803 |
| transforming proteins of fujinami and prcii avian sarcoma viruses have different subcellular locations. | the subcellular locations of transforming proteins encoded by the related avian sarcoma viruses, prcii and fujinami sarcoma virus (fsv), were compared by cell fractionation and by indirect immunofluorescence. whereas both viruses encode gag-fps proteins associated with tyrosine-specific kinase activity, fsv is more highly tumorigenic than prcii in vivo. cell fractionation studies showed that the prcii transforming protein, p105, became associated with the high-speed particulate fraction shortly ... | 1984 | 6328747 |
| serine- and threonine-specific protein kinase activities of purified gag-mil and gag-raf proteins. | retroviruses carry cell-derived oncogenes (v-onc) that have the potential to transform cells in culture and induce tumours in vivo. one of the few carcinoma-inducing viruses is the acutely transforming retrovirus mh2, which carries the putative oncogene v-mil and the known oncogene v-myc. recently, a high degree of homology was discovered between v-mil and v-raf, the transforming gene of the murine retrovirus 3611 murine sarcoma virus (msv), whereas homology to v-src is low. both viruses express ... | 1984 | 6438534 |
| 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 |
| 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 |
| phosphorylation of the nonstructural proteins encoded by three avian acute leukemia viruses and by avian fujinami sarcoma virus. | the gag gene-related, nonstructural proteins of three avian acute leukemia viruses (namely, myelocytomatosis viruses mc29 and cmii and avian erythroblastosis virus) and of avian fujinami sarcoma virus (fsv) isolated by immunoprecipitation from cellular lysates with anti-gag serum were shown to be phosphoproteins in vivo. the specific 32p radioactivity of the nonstructural proteins of mc29, cmii, and fsv was significantly higher than that of helper viral, intracellular gag proteins. two of these ... | 1980 | 6253683 |
| [cellular factors participating in cell transformation]. | to clarify the cellular target(s) of onc gene products of moloney murine sarcoma virus (mo-msv), we isolated eight mutant cells that exhibit temperature-sensitivity for transformation by wild type mo-msv from f2408 (fischer rat cell line). these mutant cells showed normal growth and normal mo-msv production at the nonpermissive temperature, suggesting that cellular and viral replication are not affected by these cellular mutations. these mutant cells are divided into 3 classes on the bases of te ... | 1983 | 6881989 |
| 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 |
| characterization of protein kinase activity associated with the transforming gene product of fujinami sarcoma virus. | 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 nucleotid ... | 1980 | 6257396 |
| a strain of fujinami sarcoma virus which is temperature-sensitive in protein phosphorylation and cellular transformation. | 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 imm ... | 1980 | 6257397 |
| ok10, an avian acute leukemia virus of the mc 29 subgroup with a unique genetic structure. | the rna of defective avian acute leukemia virus ok10 was isolated from a defective virus particle, released by ok10-transformed nonproducer avian fibroblasts, as a 60s complex consisting of 8.6-kilobase subunits. oligonucleotide fingerprinting and rna.cdna hybridization identified two sets of sequences in ok10 rna: group-specific sequences, which are related to all nondefective members of the avian tumor virus group, and a sequence closely related to the subgroup-specific sequences (mcv) of the ... | 1980 | 6261241 |
| mutants of fujinami sarcoma virus which are temperature sensitive for cellular transformation and protein kinase activity. | two temperature-sensitive mutants of fujinami sarcoma virus were isolated and characterized. cells infected with the mutants were temperature sensitive in focus formation, colony formation, increased sugar uptake, and synthesis of plasminogen activator. the changes between transformed and nontransformed states of cultures were completely reversible by shifting the temperature. a fujinami sarcoma virus-specific protein of 130,000 daltons, p130, was synthesized in mutant-infected cells regardless ... | 1981 | 6264108 |
| genetic structure, transforming sequence, and gene product of avian sarcoma virus ur1. | we analyzed the genetic structure and gene products of the newly isolated avian sarcoma virus ur1, which recently has been shown to be replication defective and to contain no sequences homologous to the src gene of rous sarcoma virus. the sizes of the genomic rnas of ur1 and its associated helper virus, ur1av, were determined to be 29s and 35s (5.9 and 8.5 kilobases), respectively, by gel electrophoresis and sucrose gradient sedimentation. rnase t1 oligonucleotide mapping of purified viral rnas ... | 1981 | 6270378 |
| structure and phosphorylation of the fujinami sarcoma virus gene product. | the fujinami avian sarcoma virus (fsv) transforming gene product, p140, is a fusion protein which contains both gag-related and fsv-specific methionine-containing tryptic peptides. the virion protease p15 cleaved p140 into two fragments: an n-terminal 33k fragment which contained all but one of the gag-related tryptic peptides and a c-terminal 120k fragment which contained all of the fsv-specific tryptic peptides. the 33k gag-related fragment from p140 phosphorylated in fsv-transformed cells con ... | 1981 | 6275111 |
| nucleotide sequence of fujinami sarcoma virus: evolutionary relationship of its transforming gene with transforming genes of other sarcoma viruses. | we determined the entire nucleotide sequence of the molecularly cloned dna of fujinami sarcoma virus (fsv). the sequence of 1182 amino acids was deduced for the fsv transforming protein p130, the product of the fsv gag-fps fused gene. the p130 sequence was highly homologous to the amino acid sequence obtained for the gag-fes protein of feline sarcoma virus, supporting the view that fps and fes were derived from a cognate cellular gene in avian and mammalian species. in addition, fsv p130 and p60 ... | 1982 | 6291784 |
| reactivation of host-dependent src kinase activity by co-expression with a heterologous tyrosine kinase. | xd4 is a host range deletion mutant (delta 77-225) of the v-src transforming gene. this mutant transforms chicken embryo fibroblasts (cef) but not rat-2 cells. it encodes a product (xd4-src) that is phosphorylated at tyrosine and active as a tyrosine kinase in cef, but is neither phosphorylated at tyrosine nor active as a kinase in rat-2 cells. we report here that the xd4-src kinase activity in rat-2 cells can be restored by co-expression with the tyrosine kinase encoded by v-fps, but not by co- ... | 1993 | 8317103 |
| 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 |
| biochemical characterization of transformation-specific proteins of acute avian leukemia and sarcoma viruses. | the biological and biochemical properties of the transformation-specific proteins of three avian oncornaviruses with different oncogenic potentials were compared, namely the gag-myc protein of the avian myelocytomatosis virus mc29, the gag-erb a protein of the avian erythroblastosis virus aev, and the gag-fps protein of fujinami sarcoma virus fsv. these oncogenes were analyzed in transformed fibroblasts that expressed only the transforming proteins but showed no virus replication. monoclonal ant ... | 1982 | 6298258 |
| cytoplasmic localization of the transforming protein of fujinami sarcoma virus: salt-sensitive association with subcellular components. | fujinami sarcoma virus (fsv) encodes a transforming protein of 130,000 daltons (p130) which is associated with a tyrosine-specific protein kinase activity. to elucidate mechanisms involved in cell transformation by fsv, we have studied the intracellular location of p130 in rat cells nonproductively infected with fsv. immunofluorescent staining of several fsv-transformed rat cell lines with a tumor regressor antiserum specific against the fps sequences of p130 showed that the major staining was l ... | 1983 | 6300435 |
| decreased dna-binding ability of purified transformation-specific proteins from deletion mutants of the acute avian leukemia virus mc29. | avian myelocytomatosis virus mc29 is a highly oncogenic replication-defective retrovirus that predominantly affects hematopoietic cells and causes acute leukemia in vivo and that transforms hematopoietic cells as well as fibroblasts in vitro. the transformation-specific sequence, v-myc, is expressed as part of a fusion protein that contains the viral structural protein p19. by use of monoclonal antibodies against p19 we showed that the v-myc-encoded protein is located in the nucleus of mc29-tran ... | 1983 | 6304686 |
| reduced binding of epidermal growth factor by avian sarcoma virus-transformed rat cells. | rat cells transformed by rous sarcoma virus and fujinami sarcoma virus bound 5-10% of the amount of epidermal growth factor (egf) bound by normal cells. scatchard plot analysis indicated that the reduction in binding by transformed cells was due to a decreased number of receptors rather than to altered binding affinity. in experiments with temperature sensitive mutants of rous sarcoma virus and fujinami sarcoma virus significant loss of egf binding occurred within one hour of shift from non-perm ... | 1983 | 6307296 |
| 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 |