Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The possible alteration of transformation-related antigens in cells that revert to a normal phenotype but that continue to retain the viral genome, has been investigated in [3H]glucosamine-labeled extracts of rat cells exhibiting a reversible temperature-dependent restriction in the expression of transformation and in a comparison of a morphologically altered mouse cell transformed by the Kirsten sarcoma virus with a flat revertant mouse cell derived from the morphologically transformed cells. With the use of normal goat serum in the presence of dibutyryl cyclic 3':5'-adenosine monophosphate, some differences became obvious in the rat cells restricted in the expression of transformation. However, use of specific antiserum to murine leukemia virus revealed in every case the presence of major components that exhibited an electrophoretic mobility corresponding to about 100,000 daltons both in the parent and revertant mouse cells and in the rat cells exhibiting either untransformed or transformed growth properties. The glycoprotein components detected only by the immune serum may represent a cellular macromolecule antigenically related to an interspecies C-type viral species whose concentration is increased in transformed cells.
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PMID:Continued presence of similar transformation-associated antigens related to murine oncornavirus proteins in -ransformed cells, morphological revertants, and cells restricted in the expression of transformation. 19 Nov 80

The glycopeptides obtained by pronase digestion of two ecotropic strains of murine leukemia virus (MuLV) were compared by gel filtration. Four different glycopeptide size classes, designated G(1), G(2), G(3), and G(4), with molecular weights of approximately 5,100, 2,900, 2,200, and 1,500, respectively, were shown to be associated with Rauscher MuLV virions grown in JLS-V9 cells. Various sugar precursors, including glucosamine, galactose, fucose, and mannose were incorporated into G(1) and G(2), suggesting that these are complex (type I) glycopeptides. The two smaller glycopeptide size classes, G(3) and G(4), were shown to be mannoserich (type II) glycopeptides. G(4) was more sensitive to digestion with endo-beta-N-acetylglucosaminidase H than G(3), suggesting that the core of G(3) may contain fewer mannose residues. Glycopeptides of the same size class as G(1) and G(2) were associated with both Rauscher MuLV and AKR-MuLV grown in III6A (mouse embryo) cells. Previous studies have shown that gp52, a proteolytic cleavage product of gp70, possessed primarily G(1) glycopeptides and that gp52 was more highly sulfated than gp70. We observed that G(1) is approximately twofold more highly sulfated than G(2), explaining the observed difference in sulfation of gp52. The unusually large size of G(1) suggested that infection with MuLV may alter the host cell glycosylation pattern. To test this possibility, glycopeptides from Sindbis virions grown in uninfected and Rauscher MuLV-infected JLS-V9 cells were compared, and no differences were observed. G(1) was not detected in Sindbis virions, indicating that acquisition of G(1) depends on properties of the virus-coded polypeptide backbone of the gp70 molecule.
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PMID:Glycopeptides of murine leukemia viruses. I. Comparison of two ecotropic viruses. 22 50

We have measured the plasma level of a fucosyltransferase in patients with acute myelogenous leukemia and non-Hodgkin's lymphoma at various stages of the disease and in normal controls. This enzyme transfers the sugar fucose from a guanosine diphosphate-L-fucose donor to high-molecular-weight acceptors with a terminal N-acetyl-glucosamine residue. The enzyme levels of fucosyltransferase in individuals free from disease and in patients with untreated leukemia or lymphoma were comparable. A substantial increase in plasma enzyme level was measured during drug-induced remissions, three weeks after drug therapy. The enzyme level fell to the normal range during unmaintained remissions inpatients with lymphomas; comparable information for the leukemia is not available since all remissions were drug maintained. These data, together with microscopic examination of marrow samples, indicate that the level of this fucosyltransferase is correlated with regeneration of a normal marrow population after chemotherapy. The enzyme assay may prove useful in defining normal bone marrow recovery and in timing cyclic combination chemotherapy in patients with neoplastic disease.
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PMID:Guanosine diphosphate-L-fucose plasma: N-acetylglucosaminide fucosyltransferase as in index of bone marrow hyperplasia after chemotherapy. 27 Oct 43

This work describes the detection, isolation, and partial characterization of a BALB/c mouse fibroblast cell surface antigen. This antigen migrates as a polypeptide of approximately 100,000 daltons in a discontinuous sodium dodecyl sulfate/polyacrylamide gel electrophoresis system, can be labeled by either lactoperoxidase-catalyzed cell surface 125I iodination or metabolic incorporation of [3H]glucosamine, and can be isolated by concanavalin A affinity chromatography. This cell surface glycoprotein is antigenic in BALB/c mice and has been correlated with the rejection of immunogenic tumor cells. Also, antiserum specific for Moloney leukemia virus precipitates the 100,000-dalton cell surface protein from viral and immunogenic spontaneous transformants. This virus-related antigen comigrates on sodium dodecyl sulfate gels with the major iodinated cell surface protein of these transformants. Rabbit antiserum to the purified antigen demonstrates a marked preference for the surfaces of immunogenic tumor cells as compared with normal cells and nonimmunogenic tumor cells.
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PMID:Isolation and characterization of a tumor cell surface antigen from spontaneously transformed BALB/c mouse fibroblasts. 28 13

Post-translational modifications of retrovirus gag gene-encoded polyproteins include proteolytic cleavage, phosphorylation, and glycosylation. To study the sequence of these events, we labeled JLS-V9 cells chronically infected with Rauscher murine leukemia virus in pulse-chase experiments with the radioactive precursors [35S]methionine, [14C]mannose, [3H]glucosamine, and [32P]phosphate. Newly synthesized gag polyproteins which incorporated label, and the modified products derived from them, were identified by immunoprecipitation of cell lysates with anti-p30 rabbit serum, followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. Pulse-chase experiments were carried out in the presence as well as in the absence of tunicamycin, an inhibitor of glycosylation. Among the three major polyproteins synthesized in the absence of tunicamycin, two were found to be glycosylated but not phosphorylated. These were designated gPr80gag and gP94gag. Both shared identical [35S]methionine peptides with Pr65gag and p30. Of the two nonglycosylated precursors, Pr65gag and Pr75gag, only Pr65gag was found to be detectably phosphorylated, and Pr75gag could be readily identified only when glycosylation was inhibited. On the basis of these results, a scheme for the post-translational modification of gag polyproteins is proposed. According to this scheme the gag gene-encoded polyproteins are processed from a common precursor, Pr75gag, by two divergent pathways: one leading through the intermediate Pr65gag to internal virion components via cleavage and phosphorylation and the other via tunicamycin-sensitive mannosylation to the intermediate gPr80gag, which is further glycosylated to yield cell surface polyprotein gP94gag.
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PMID:Post-translational modification of Rauscher leukemia virus precursor polyproteins encoded by the gag gene. 48 Apr 54

Synthesis and post-translational processing of murine leukemia virus proteins were analyzed in a murine cell line (Eveline) that produces large amounts of Friend lymphatic leukemia virus. Immunoprecipitation of l-[(35)S]methionine-labeled cell extracts demonstrated that several different virus-specific proteins antigenically related to the virion core (gag) proteins p12 and p30 become radioactive within 1 min of labeling and exhibit labeling kinetics characteristic of primary translation products. The most abundant of these were proteins with molecular weights of 75,000 and 65,000. There were, in addition, two large glycosylated polyproteins with apparent molecular weights of 220,000 and 230,000, which were precipitated by antisera to p30 or p12 but not by antiserum to the major envelope glycoproteins gp69/71. Several lines of evidence, including labeling with d-[(3)H]glucosamine and binding to insolubilized lectins, suggested that the 75,000-dalton internal core polyprotein is slowly processed to form a glycoprotein with an apparent molecular weight of 93,000. On the contrary, the 65,000-dalton protein appeared to be an immediate precursor to the virion core proteins. Its processing can involve intermediates containing p30 and p12 antigens with molecular weights of 50,000 and 40,000; however, the latter did not appear to be obligatory intermediates. The detection of the 40,000-dalton protein suggested that the genes for p30 and p12 are adjacent on the viral genome. These results indicated that there are several pathways of synthesis and post-translational processing of polyprotein precursors to the gag proteins and that several of these polyproteins are glycosylated. A comparison of gag precursor processing in rapidly growing, slowly growing, and stationary cells indicated that different pathways are favored under different conditions of cell growth. Our analysis of envelope glycoprotein synthesis has confirmed the existence of two rapidly labeled 90,000-dalton glycoproteins, which appear to be precursors to the envelope glycoproteins gp69/71.
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PMID:Synthesis and glycosylation of polyprotein precursors to the internal core proteins of Friend murine leukemia virus. 59 67

Antisera to disrupted Rauscher leukemia virus (RLV) or to the purified Rauscher viral 30,000 dalton polypeptide were used to specifically precipitate newly snythetized intracellular viral polypeptides from extracts of infected NIH Swiss mouse cells (JLS-V16). Analysis by SDS-polyacrylamide gel electrophoresis (SDS-PHAGE) of extracts from cells pulse-labeled for 10-20 min with 35 S-methionine showed that immune precipitates contained none of the nonglycosylated internal structural polypeptides of mature viruses. The major viral-specific polypeptides labeled in 10 min included polypeptides of 180,000, 140,000, 110,000, 80,000, and 60,000 daltons with minor polypeptides of 65,000, 50,000, and 40,000 daltons. Labeling the intracellular virus-specific polypeptides with 14C-glucosamine indicated that the 180,000, 110,000, 80,000, and 60,000 dalton polypeptides were gylcosylated, and all but the 110,000 dalton polypeptides are contained in the mature virions. Based on pulse-chase experiments, it appears that at least 3 of the large polypeptides (140,000, 65,000, and 50,000 daltons) are precursors to the three major internal structural polypeptides of the mature virions.
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PMID:Biosynthesis of Rauscher leukemia viral proteins. 80 75

Rat basophilic leukemia cells were labeled either enzymically with 125I or biosynthetically by culture in the presence of 14C-glucosamine or 3H-amino-acids and then extracted with NP-40. IgE-anti-IgE precipitates insolubilized a radiolabeled macromolecule from these extracts largely or entirely absent in control IgG-anti-IgG percipitates. When specific precipitates were boiled in sodium dodecyl sulfate (SDS) and analyzed by polyacrylamide gel electrophoresis in the presence of SDS, most of the 14C or 125I radioactivity was in the area corresponding to an apparent m.w of 60,000 to 70,000 in 5.9% gels. In 10% and 12% gels, faster mobility was demonstrated indicating an atypical electrophoretic behavior often associated with glycoproteins and a presumptive m.w. of 50,000 or less. Since only IgE-containing precipitates localized label in this region and since such precipitates from cells saturated with IgE prior to surface iodination failed to show this band, the labeled macromolecule appears to be the IgE receptor itself. Analysis of the acid hydrolysates of precipitated 14C radioactivity demonstrated that label was entirely in hexosamines and sialic acid. 125I and 14C labels in the recepotr region were eliminated almost completely with pepsin and pronase and to a lesser extent with trypsin.
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PMID:The rat basophilic leukemia cell receptor for IgE. I. Characterization as a glycoprotein. 82 Aug 4

Rauscher leukemia virus glycoprotein gp69/71 is synthesized in virus-infected cells by way of a 90,000 dalton glycoprotein precursor, termed Pr2a+b. This precursor could be labeled with radioactive glucosamine and methionine but not with fucose; whereas gp69/71 could be detected by labeling with radioactive glucosamine, fucose, or a mixture of amino acids but seemed to be deficient in methionine relative to Pr2a+b. Pr2a+b and gp69/71, were specifically precipitated by an antiserum prepared against phosphocellulose purified Rauscher gp69/71. Other virus-specific precursors, in addition to Pr2a+b, could be precipitated by antiserum prepared against detergent disrupted virus. Neither Pr2a+b nor gp69/71 was precipitated from cell extracts by antisera to Rauscher p30. Tryptic maps of Pr2a+b and gp69/71 showed that these glycoproteins share many tryptic peptides. Pulse-chase experiments with 14C-labeled amino acids indicated that gp69/71 was not radio-labeled during the pulse-labeling period but slowly appeared during the chase incubations. Pr2a+b, however, was rapidly labeled and tended to disappear during long chases. Furthermore, two nonglycosylated viral proteins, termed p15E and p12E, are structurally related to Pr2a+b. Viral p15E and p12E contained the same methionine-containing tryptic peptide fraction as Pr2a+b as determined by ion-exchange chromatography. These results provide evidence that Pr2a+b is a precursor to gp69/71 and establish a structural and possible precursor-product relationship between Pr2a+b, p15E, and p12E.
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PMID:A fucose-deficient glycoprotein precursor to Rauscher leukemia virus gp69/71. 106 81

The gangliosides of control rat embryo cells, 3-methylcholanthrene, Rauscher leukemia virus, and combined 3-methylcholanthrene-Rauscher leukemia virus transformants were examined using [14 C]glucosamine as a tracer. All four cell lines exhibited a complex pattern of gangliosides. While N-acetylgalactosaminyl-(N-acetylneuraminyl)-galactosyl-glucosyl-ceramide was the major ganglioside in the control cell line, N-acetylneuraminyl-galactosyl-glucosyl-ceramide was the major ganglioside in the three transformants. The 3-methylcholanthrene transformant possessed a ganglioside pattern different from that of the Rauscher leukemia virus transformant. Hydrolysis of the gangliosides indicated that galactosamine, N-acetyl-and N-glycolylneuraminic acid were the labeled components in all cell lines.
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PMID:Gangliosides of chemically and virally transformed rat embryo cells. 116 75


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