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)

Recombinant murine retroviruses containing the src gene of the avian retrovirus Rous sarcoma virus were isolated. Such viruses were isolated from cells after transfection with DNAs in which the src gene was inserted into the genome of the amphotropic murine retrovirus 4070A. The isolated viruses had functional gag and pol genes, but they were all env defective since the src gene was inserted in the middle of the env gene coding region. Infectious transforming virus could be isolated only from cells transfected with DNA constructions in which the src gene was in the same polarity as that of a long terminal repeat of the amphotropic viral genome. These recombinant viruses encoded a pp60src protein with a molecular weight similar to that of the Schmidt-Ruppin strain of Rous sarcoma virus. In addition, the src protein(s) of these recombinant viruses was as active as protein kinases in the immune complex protein kinase assay. Intravenous injection of helper-independent Moloney and Friend murine leukemia virus pseudotypes of the src recombinant viruses into 6-week-old NIH Swiss mice resulted in the appearance of splenic foci within 2 weeks, splenomegaly and, later after infection (8 to 10 weeks), anemia. Infectious transforming virus could be recovered from the spleens of diseased animals. Such viruses encoded pp60src but not p21ras or mink cell focus-forming virus-related glycoproteins.
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PMID:Construction and isolation of a transforming murine retrovirus containing the src gene of Rous sarcoma virus. 630 22

Long-term marrow cultures prepared from mice have been infected with a molecular recombinant of Rous sarcoma virus and murine amphitropic leukemia virus. This resulted in introduction of the src gene into the cultured cells and expression of its protein kinase function. The infected cultures displayed an altered balance in the accumulation of cells in different compartments of granulocyte differentiation. There was a dramatic increase in the stem cell (CFU-S) compartment and the committed progenitor cell (GM-CFC) compartment and a decrease in mature granulocytes. The altered balance appears to be caused by intrinsic alterations in the CFU-S and GM-CFC themselves, which increase their "self-renewal" capacity at the expense of cell differentiation. Remarkably, unlike its effects in other systems, src did not produce a neoplastic transformation of the hemopoietic cells.
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PMID:Effect of src infection on long-term marrow cultures: increased self-renewal of hemopoietic progenitor cells without leukemia. 632 Oct 38

In many higher animal species, a major histocompatibility complex (MHC; in man: HLA; in mice: H-2) has been established and extensively studied. MHC products are essential in the recognition and destruction of cells carrying non-self antigenic determinants. Associations between specific HLA haplotypes and susceptibility towards nasopharyngeal carcinoma, breast cancer, acute lymphocytic leukaemia and Hodgkin's disease have been reported. A summary is made of the evidence for the involvement of H-2 genes in the development of virally induced tumours (leukaemia, mammary tumours and Rous sarcoma virus-induced fibrosarcomas). The formation of mouse lung tumours, for which there is no indication of a viral or hormonal etiology, has also proved to be significantly influenced by the H-2 haplotype. Similar results were obtained for spontaneous and chemically induced lung tumours. On closer analysis, more specific parameters, such as type of lung tumour and size, were found to be controlled by several regions of the H-2 complex.
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PMID:Tumour susceptibility in mice in relation to H-2 haplotype. 636 70

Tyrosine phosphorylation seems to be a key event in the control of cellular growth. Several viral transforming proteins, including the src protein of Rous sarcoma virus, the p120 protein of Abelson leukaemia virus and the middle T antigen of polyoma virus, are phosphorylated by associated tyrosine kinases. The levels of kinase activity correlate with the transforming efficiency of the virus. The receptors for epidermal growth factor (EGF), platelet-derived growth factor (PDGF) and insulin are also phosphorylated by associated tyrosine kinase activities, which are stimulated by EGF, PDGF and insulin, respectively. The EGF-stimulated kinase and the src protein share similar substrate specificity for tyrosines immediately C-terminal to a sequence of acidic amino acids. Such a sequence is also found adjacent to the phosphotyrosine of middle T antigen, and in the homologous region of the hormone gastrin, adjacent to a tyrosine which is sulphated in approximately half the gastrin isolated from gastric mucosa. Reports that gastrin acts as a growth factor for cells of the gastrointestinal tract suggested that phosphorylation of this tyrosine might be physiologically more relevant than sulphation. We report here that synthetic human gastrin 17 is phosphorylated by the EGF-stimulated tyrosine kinase of A431 cell membranes. The Km values of 53-87 and 223-547 microM obtained in the presence and absence of EGF, respectively, are the lowest reported so far for this enzyme.
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PMID:Phosphorylation of gastrin-17 by epidermal growth factor-stimulated tyrosine kinase. 660 May 11

The Gardner-Rasheed strain of feline sarcoma virus (GR-FeSV), is a recent isolate of a naturally occurring cat sarcoma. The primary translational product of GR-FeSV (GR P70) was shown to be a phosphoprotein with associated tyrosine-specific protein kinase activity. The relationship between the GR-FeSV provirus and once genes of other transforming retroviruses known to code for tyrosine kinases was examined by molecular hybridization. Probes repesenting onc genes of Snyder-Theilen and McDonough strains of feline sarcoma virus, Rous sarcoma virus, and Abelson murine leukemia virus did not detectably hybridize integrated GR-FeSV. These findings suggest that GR-FeSV contains a distinct tyrosine kinase-coding onc gene.
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PMID:Analysis of the primary translational product and integrated DNA of a new feline sarcoma virus, GR-FeSV. 660 28

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 temperature-sensitivity for transformation by other tumor viruses such as Kirsten sarcoma virus, Rous sarcoma virus (SRD strain), Fujinami sarcoma virus and Abelson leukemia virus. These results have suggested that several kinds of cellular factors are concerned in transformation by Mo-MSV.
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PMID:[Cellular factors participating in cell transformation]. 688 89

The location and nature of the HIV-1 packaging signal are largely unknown, despite several genetic and biochemical mutational analyses. In this report we present our attempts to define a minimal HIV-1 packaging signal through the generation of test RNAs containing small blocks of HIV-1 sequences. We constructed RNAs differing in the position and identity of the HIV-1 sequence and the segments of heterologous sequences. However, none of the vectors were efficiently, encapsidated by wild-type HIV-1 virions. These results contrast those of Moloney murine leukemia virus and Rous sarcoma virus, where small viral segments mediate the efficient encapsidation of heterologous RNAs. The results suggest that the HIV-1 packaging signal may be extremely dispersed or heavily context-dependent.
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PMID:5' regions of HIV-1 RNAs are not sufficient for encapsidation: implications for the HIV-1 packaging signal. 757 42

The CA (capsid) protein of avian sarcoma and leukemia viruses occurs in multiple species. Only one form has been previously characterized biochemically. We have now determined that the mature CA protein of avian sarcoma and leukemia viruses exists as three species with different C termini, ending in amino acid residues A-476, A-478, and M-479 of the Gag precursor, respectively. These structures were deduced from a combination of cyanogen bromide peptide mapping, sequence analysis of tryptic peptides, and electrospray mass spectrometry. The three forms of CA were detected in the same ratios in Rous sarcoma virus and avian myeloblastosis virus and therefore are likely to represent a common feature of members of this genus of avian retroviruses. The only previously reported CA species, CAM-479, accounts for only about 36% of the total CA protein, while CAA-476 and CAA-478 account for 55 and 9%, respectively. From the analysis of peptides cleaved in vitro by PR, the viral protease, we infer that the cleavage site between A-476 and A-477 not only is recognized by PR but is the preferred site. We were unable to determine if A-478/A-479 is a cleavage site for PR or alternatively if CAA-478 results from further processing of CAM-479 by a carboxypeptidase. To study the biological significance of residues A-477 to M-479, we constructed genetically altered viruses in which deletions removed either residues 477 to 479 or 477 to 488. The resulting virus particles appeared to assembly with normal efficiencies, but the latter mutant showed slowed proteolytic processing. Neither of the mutants was infectious.
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PMID:Differential proteolytic processing leads to multiple forms of the CA protein in avian sarcoma and leukemia viruses. 766 44

All reverse transcriptases (RTs) so far examined are known to possess in common a stretch of 7 amino acids called the YXDD box. Various mutations were introduced in vitro into the nucleotide sequence coding for this box of Moloney murine leukaemia virus (Mo-MuLV) RT. The YXDD box of Mo-MuLV could be replaced by the counterpart of a Drosophila retrotransposon, 17.6, without loss of activity, while virtually complete loss of activity was detected in the case of replacement of the YXDD box of Rous sarcoma virus RT. Amino-acid substitution at position X resulted in significant change in divalent metal ion preference and enzyme activity, thus indicating that the YXDD box possibly constitutes a part of the active center of RT through metal ion binding.
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PMID:Chimeric reverse transcriptase of Moloney murine leukaemia virus, having the YXDD box of a Drosophila retrotransposon, 17.6. 768 14

In total, 4165 medaka (Oryzias latipes) oocytes were injected with three DNA constructs separately, and results showed that exogenous lacZ expression was transient and stage-dependent. The initiation of the transgene expression was at the mid-blastula stage for embryos derived from oocytes injected with pmiwZ, containing the long terminal repeat (LTR) of the Rous sarcoma virus, and with pCAGGS-lacZ, containing the enhancer and promoter of the immediate early gene of the human cytomegalovirus, respectively, whereas embryos derived from oocytes injected with pMoZtk, containing the LTR of the Moloney murine leukemia virus, started expression at the late-blastula stage. These reveal that the earliest onset of the exogenous lacZ gene should be by the mid-blastula stage. Therefore the mid-blastula transition phenomenon in embryogenesis known in other animal species exists in medaka embryos.
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PMID:Initiation of the transgenic lacZ gene expression in medaka (Oryzias latipes) embryos. 774 60


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