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)

A nucleotide sequence of the mouse Fv-4 env gene was completed. Structural comparison revealed a close relationship of Fv-4 to the ecotropic Cas-Br-E murine leukemia virus isolated from a wild mouse in southern California. Various portions of the env gene of Moloney murine leukemia virus were replaced by the corresponding Fv-4 env sequence to construct recombinant murine leukemia virus clones. Infectivity of these recombinants was checked by the S+L- cell focus induction assay and the XC cell syncytium formation assay. Recombinants bearing the following Fv-4 env sequence retained ecotropic infectivity; the AccI-BamHI and BamHI-BalI regions coding for the N- and C-terminal halves of Fv-4 gp70SU, respectively; and the BalI-NcoI region encoding the cleavage site between gp70SU and p15(E)TM of the Fv-4 env. However, when the Fv-4 sequence was substituted for the p15(E)TM-coding NcoI-EcoRV region or the AccI-EcoRV region covering almost the entire env gene, infectivity was undetectable in our assays. The recombinant clone containing the Fv-4 AccI-EcoRV region, i.e., almost the entire Fv-4 env sequence, was introduced with pSV2neo into NIH 3T3 cells, and a G418r cell line named NIH(Fv4)-2 was isolated. The NIH(Fv4)-2 cell released viral particles that contained reverse transcriptase, Fv-4 env molecules as well as the other viral proteins, and viral genomic RNA. However, proviral DNA synthesis was not detected upon inoculation of this virus in NIH 3T3 cells. The loss of infectivity of the recombinant virus bearing the Fv-4 AccI-EcoRV region appeared to be caused by failure in an early step of replication.
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PMID:Construction and characterization of the recombinant Moloney murine leukemia viruses bearing the mouse Fv-4 env gene. 230 38

We have made a computer-assisted search for homology among polymerases or putative polymerases of various viruses and a transposable element, the Drosophila copia-like element 17.6. The search revealed that the putative polymerase (second open reading frame) of the copia-like element 17.6 bears close resemblance in overall structural organization to the pol gene product of Moloney murine leukaemia virus (M-MuLV): they show significant homology to each other at both the N- and C-terminal portions, suggesting that the 17.6 putative polymerase carries two enzymatic activities, related to reverse transcriptase and DNA endonuclease. The putative polymerase of cauliflower mosaic virus (CaMV) shows striking homology with the putative polymerase of 17.6 over almost its entire length, but it lacks the DNA endonuclease-related sequence. Furthermore, it was shown that the N-terminal ends of the M-MuLV pol product and the CaMV and 17.6 putative polymerases exhibit strong sequence homology with the gag-specific protease (p15) of Rous sarcoma virus (RSV) as well as the amino acid sequence predicted from the gag/pol spacer sequence of human adult T-cell leukaemia virus (HTLV). These p15-related sequences contain a highly conserved stretch of amino acids which show a close similarity with sequences around the active site amino acids Asp-Thr-Gly of the acid protease family, suggesting that they have an activity similar to acid protease. On the basis of the alignment of reverse transcriptase-related sequences, a dendrogram representing phylogenetic relationships among all the viruses compared together with 17.6 was constructed and its evolutionary implication is discussed.
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PMID:Close structural resemblance between putative polymerase of a Drosophila transposable genetic element 17.6 and pol gene product of Moloney murine leukaemia virus. 240 86

To analyze cell surface murine leukemia virus gag protein expression, we have prepared monoclonal antibodies against the spontaneous AKR T lymphoma KKT-2. One of these antibodies, 43-13, detects an AKR-specific viral p12 determinant. A second monoclonal antibody, 43-17, detects a novel murine leukemia virus-related antigen found on glycosylated gag polyproteins (gp95gag, gp85gag, and gp55gag) on the surface of cells infected with and producing ecotropic endogenous viruses, but does not detect antigens within these virions. The 43-17 antibody immunoprecipitates the precursor of the cell surface gag protein whether in its glycosylated or unglycosylated state, but does not detect the cytoplasmic precursor of the virion gag proteins (Pr65gag). Based on these findings, we have localized the 43-17 determinant to the unique amino-terminal part of the glycosylated gag polyprotein (the L domain). We have determined that gp95gag contains L-p15-p12-p30-p10 determinants, whereas gp85gag lacks the carboxyterminal p10 determinant, and gp55gag lacks both p30 and p10 carboxy terminal determinants. Analysis of cell surface gag expression with the 43-17 antibody leads us to propose that the L domain plays a crucial role in (i) the insertion and orientation of murine leukemia virus gag polyproteins in the cell membrane and (ii) the relative abundance of expression of AKR leukemia virus versus Moloney murine leukemia virus glycosylated gag polyproteins in infected cells.
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PMID:Monoclonal antibody to the amino-terminal L sequence of murine leukemia virus glycosylated gag polyproteins demonstrates their unusual orientation in the cell membrane. 241 13

The molecular size and pI of the viral structural proteins of four PVC viruses (PVC111, PVC211, PVC321 and PVC441) were compared by single or two-dimensional polyacrylamide gel electrophoresis. PVC111 had slightly larger p15E and gPr85 molecules (about 0.5 kilodalton) than did the other PVC viruses. On the other hand, the virion structural proteins p30, p15, p12E and p12 from all the viruses had the same molecular sizes and pIs. The gp70s and p10s from all the viruses showed the same molecular sizes. A monoclonal antibody to gp70 of PVC321 virus recognized the gp70s of all PVC viruses, but not the gp70s of four clones of the wild mouse ecotropic viruses, Friend murine leukemia viruses (F-MuLV), AKR ecotropic MuLV, dual-tropic F-MuLV or NZB endogenous xenotropic MuLV, revealing that these four PVC viruses are homologous with each other, but distinct from the known mouse retroviruses.
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PMID:Biochemical and immunological characterization of murine leukemia viruses that are paralysis-inducing in rats. 254 Jan 31

By means of SDS PAGE we isolated from virus-infected foetal lamb kidney (FLK) cells a relatively homogenous envelope transmembrane protein gp30 of bovine leukaemia virus (BLV). As shown by a partial sequence analysis of the N-terminus of this protein, our gp30 preparation contained only traces (less than 5%) of p24 gag protein: Rabbit anti-gp30 serum did not cross react with the BLV proteins gp51, p12, p15(1), p15(2), and p10 but reacted weakly with the p24 polypeptide. 125I-labelled gp30 (chloramine-T) was precipitated with the serum of BLV-infected cattle. Nonlabelled preparation of gp30 competitively inhibited the reaction of 125I-labelled gp30 with the natural antibodies. We investigated 193 cattle sera by liquid phase radioimmunoassays (RIA) using 125I-gp30, gp51 and p24 antigens. Sixteen noninfected cattle sera were negative in all tests. The 177 serum samples of BLV-infected animals were examined to the diagnostic value of the three tests. Of these, 175 were positive in gp51 RIA, 172 in p24 RIA and 164 in gp30 RIA. In all three tests, 159 sera were positive while 18 sera, mostly coming from animals with normal leukocyte counts, were positive only either with gp51 or p24, or were double positive with either gp51/p24 or gp51/gp30. We conclude that the gp51 RIA is superior to both the gp30 and the p24 RIA and that the gp30 RIA will be useful for investigating the role of gp30 in virus pathogenicity.
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PMID:A radioimmunoassay detecting the bovine leukaemia virus transmembrane protein gp30 and anti-gp30 antibodies in the serum of cattle. 256 6

In vitro cleavage of Gazdar murine sarcoma virus Pr65gag, which has all of the antigenic determinants of Moloney murine leukaemia virus Pr65gag, i.e. p15, p12, p30 and p10, by the Moloney murine leukaemia virus proteolytic activity yielded a p30 whose partial NH2-terminal sequence was identical to Moloney murine leukaemia virus. Both [3H]leucine-labelled and unlabelled Pr65gag were used to generate the cleaved p30.
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PMID:In vitro cleavage of Pr65gag by the Moloney murine leukaemia virus proteolytic activity yields p30 whose NH2-terminal sequence is identical to virion p30. 257 53

The full-length provirus of human T-cell leukemia virus type I (HTLV-I) was isolated from MT-2, a lymphoid cell line producing HTLV-I. In transfected cells, structural proteins of HTLV-I, the gag and env products, were formed and processed in the same manner as observed in MT-2 cells. The nucleotide sequence was determined for a region between the gag and pol genes of the proviral DNA clone containing an open-reading frame. The deduced amino acid sequences show that this open-reading frame encodes a putative HTLV-I protease. The protease gene (pro) of HTLV-I was investigated using a vaccinia virus expression vector. Processing of 53k gag precursor polyprotein into mature p19, p24, and p15 gag structural proteins was detectable with a recombinant plasmid harboring the entire gag- and protease-coding sequence. We demonstrated that the protease processed the gag precursor polyprotein in a trans-action. A change in the sequence Asp(64)-Thr-Gly, the catalytic core sequence among aspartyl proteases, to Gly-Thr-Gly was shown to abolish correct processing, suggesting that HTLV-I protease may belong to the aspartyl protease group. The 76k gag-pro precursor polyprotein was identified, implying that a cis-acting function of HTLV-I protease may be necessary to trigger the initial cleavage event for its own release from a precursor protein, followed by the release of p53 gag precursor protein. The p53 gag precursor protein is then processed by the trans-action of the released protease to form p19, p24, and p15.
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PMID:Identification of HTLV-I gag protease and its sequential processing of the gag gene product. 266 87

A patient whose leukaemic cells carried the rare t(7;11)(p15;p15) was diagnosed as having acute myelomonocytic leukaemia (AML-M4), and supports the association of this specific translocation with forms of acute myeloid leukaemia showing differentiation. Blast phase chronic myeloid leukaemia was excluded by lack of involvement of the ABL and BCR genes. Chromosome in situ hybridization studies showed that both the HRAS1 and INS genes were present on the terminal part of chromosome 11p which was translocated to chromosome 7p. Neither HRAS1 nor INS were structurally rearranged. Field inversion gel electrophoresis showed that a 400 kb fragment encompassing HRAS1 was structurally entire in leukaemic DNA. Because the INS gene, which was also translocated, is probably located proximal to HRAS1 on chromosome 11p, it is unlikely that HRAS1 was near the chromosome 11 breakpoint or involved in this leukaemia.
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PMID:HRAS1 and INS genes are relocated but not structurally altered as a result of the t(7;11)(p15;p15) in a clone from a patient with acute myeloid leukaemia (M4). 271 71

The distribution of Moloney murine leukemia virus gp70/p15 E between cell surface and intracellular compartments and the kinetics of transfer between these compartments was examined in psi 2 cells. A novel biotin derivatization and recovery assay was used to quantitate pulse-labeled protein accessible at 4 degrees C (cell surface), 18 degrees C (cell surface and an intracellular compartment), or inaccessible at any temperature. Cell surface (4 degrees C) gp70 and p15 E turn over more rapidly than intracellular pools of these proteins. The decrease in cell surface gp70 and p15 E after one hour of chase is accounted for by an increase in that which is inaccessible to biotinyl reagent.
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PMID:Turnover and compartmentation of gp70/p15 E in psi 2 cells. 273 11

Human T-cell leukemia virus (HTLV) type I-related endogenous sequences (HRES) have been cloned from a human genomic library. HRES-1/1 is present in DNA of all normal donors examined. By nucleotide sequence analysis, HRES-1/1 contains two potential open reading frames capable of encoding a p25 and a p15. A 684 bp flanking region 5' from the first ATG codon of p25 contains a TATA-box, a poly-adenylation signal, a putative tRNA primer binding site, and inverted repeats at locations which are typical of a retroviral long terminal repeat. Phylogenetic analysis suggests that HRES-1/1 entered the genome in primates, presumably as an exogenous retrovirus. From the deduced amino acid sequence of HRES-1/1 p25, residues 6-36 show a sequence homology of 32% and 39% to gag region segments of HTLV-I and HTLV-II, while residues 104-139 display a sequence homology of 33% and 28% to the gag regions of human immunodeficiency virus type 2 (HIV-2) and feline sarcoma virus (FSV), respectively. This suggests that the original exogenous virus infecting primate may be chimeric in structure. The HRES-1/1 genomic locus is transcriptionally active in lymphoid cells, melanoma cells, and embryonic tissues.
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PMID:Detection and cloning of new HTLV-related endogenous sequences in man. 278 Mar 12


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