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Lieschke GJ, Dunn AR. Development of functional macrophages from embryonal stem cells in vitro. Exp Hematol 1995; 23:328-34. [PMID: 7534713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
When cultured under appropriate in vitro conditions, embryonal stem cells (ESCs) form embryoid bodies (EBs) that contain mature hematopoietic cells, including cells of the monocyte-macrophage lineage. A two-step in vitro culture system for generation of ESC-derived macrophages has been developed and optimized. Maximum numbers of macrophage-containing colonies developed in secondary hematopoietic cultures of cells from disrupted EBs after 9 to 12 days of differentiation when interleukin-3 (IL-3) and macrophage colony-stimulating factor (M-CSF) were included in both primary and secondary cultures. Over 10(5) viable, phagocytically active macrophages were generated from cultures initiated by 7500 ESCs. The inclusion of stem cell factor (SCF) in primary cultures not only increased the frequency of progenitor cells but also the cellular heterogeneity of colonies. SCF in secondary cultures increased the cellularity, but not the frequency, of macrophage-containing colonies; although cellular heterogeneity was also increased, there was still an overall increase in yield of macrophages.
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77
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Alexander WS, Dunn AR. Structure and transcription of the genomic locus encoding murine c-Mpl, a receptor for thrombopoietin. Oncogene 1995; 10:795-803. [PMID: 7862460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We have cloned and characterised the murine gene encoding c-Mpl, a receptor for thrombopoietin and member of the hematopoietin receptor superfamily. The gene encompasses 15 kb of the mouse genome and the organisation of its 12 exons conforms closely to the pattern observed for the genes of other hematopoietin receptor family members. A site for initiation of c-mpl transcription was identified 13 nucleotides upstream of the proposed translation initiation codon. The murine mpl promoter sequence lacks conventional TATA and CAAT motifs although the transcription initiation site shares homology with the initiator sequence that specifies transcription initiation in the terminal deoxynucleotidyl transferase gene. The promoter contains consensus binding sequences for several transcriptional regulators including Ets and GATA factors, which have been implicated in control of transcription in megakaryocytes, a cell type that expresses mpl. The generation of multiple transcripts is a feature of the mpl locus. Two distinct mpl transcripts differing by an in-frame insertion of 24 nucleotides were detected in mouse spleen cells. Genomic sequence analysis identified differential splicing of alternative exon 4 sequences as the likely basis for these transcripts, which are predicted to encode receptors which differ within the first Mpl hematopoietin receptor domain.
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Lieschke GJ, Grail D, Hodgson G, Metcalf D, Stanley E, Cheers C, Fowler KJ, Basu S, Zhan YF, Dunn AR. Mice lacking granulocyte colony-stimulating factor have chronic neutropenia, granulocyte and macrophage progenitor cell deficiency, and impaired neutrophil mobilization. Blood 1994; 84:1737-46. [PMID: 7521686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Mice lacking granulocyte colony-stimulating factor (G-CSF) were generated by targeted disruption of the G-CSF gene in embryonal stem cells. G-CSF-deficient mice (genotype G-CSF-/-) are viable, fertile, and superficially healthy, but have a chronic neutropenia. Peripheral blood neutrophil levels were 20% to 30% of wild-type mice (genotype G-CSF+/+) and mice heterozygous for the null mutation had intermediate neutrophil levels, suggesting a gene-dosage effect. In the marrow of G-CSF-/- mice, granulopoietic precursor cells were reduced by 50% and there were reduced levels of granulocyte, macrophage, and blast progenitor cells. Despite G-CSF deficiency, mature neutrophils were still present in the blood and marrow, indicating that other factors can support neutrophil production in vivo. G-CSF-/- mice had reduced numbers of neutrophils available for rapid mobilization into the circulation by a single dose of G-CSF. G-CSF administration reversed the granulopoietic defect of G-CSF-/- mice. One day of G-CSF administration to G-CSF-/- mice elevated circulating neutrophil levels to normal, and after 4 days of G-CSF administration, G-CSF+/+ and G-CSF-/- marrows were morphologically indistinguishable. G-CSF-/- mice had a markedly impaired ability to control infection with Listeria monocytogenes, with diminished neutrophil and delayed monocyte increases in the blood and reduced infection-driven granulopoiesis. Collectively, these observations indicate that G-CSF is indispensible for maintaining the normal quantitative balance of neutrophil production during "steady-state" granulopoiesis in vivo and also implicate G-CSF in "emergency" granulopoiesis during infections.
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79
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Lieschke GJ, Stanley E, Grail D, Hodgson G, Sinickas V, Gall JA, Sinclair RA, Dunn AR. Mice lacking both macrophage- and granulocyte-macrophage colony-stimulating factor have macrophages and coexistent osteopetrosis and severe lung disease. Blood 1994; 84:27-35. [PMID: 8018921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Mice deficient in granulocyte-macrophage colony-stimulating factor (GM-CSF) and macrophage colony-stimulating factor (M-CSF, CSF-1) were generated by interbreeding GM-CSF-deficient mice generated by gene targeting (genotype GM-/-) with M-CSF-deficient osteopetrotic mice (genotype M-/-, op/op). Mice deficient in both GM-CSF and M-CSF (genotype GM-/-M-/-) are viable and have coexistent features corresponding to mice deficient in either factor alone. Like M-CSF-deficient mice, they have osteopetrosis and are toothless because of failure of incisor eruption. Like GM-CSF-deficient mice, they have a characteristic alveolar-proteinosis-like lung pathology, but it is more severe than that of GM-CSF-deficient mice and is often fatal. In particular, in GM-/-M-/- mice the accumulation of lipo-proteinaceous alveolar material is more marked, and bacterial pneumonic infections are more prevalent and more extensive, particularly involving Gram-negative bacteria. Neutrophilia consistently accompanies pulmonary infections, and some older GM-/-M-/- mice have polycythemia. Survival of GM-/-M-/- mice is significantly reduced compared with mice deficient in either factor alone, and all GM-/-M-/- mice have broncho- or lobar-pneumonia at death. These observations indicate that in vivo, M-CSF is involved in modulating the consequences of GM-CSF deficiency in the lung. Interestingly, GM-/-M-/- mice have circulating monocytes at levels comparable with those in M-CSF-deficient mice and the diseased lungs of all GM-/-M-/- mice contain numerous phagocytically active macrophages, indicating that in addition to GM-CSF and M-CSF, other factors can be used for macrophage production and function in vivo.
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Stanley E, Lieschke GJ, Grail D, Metcalf D, Hodgson G, Gall JA, Maher DW, Cebon J, Sinickas V, Dunn AR. Granulocyte/macrophage colony-stimulating factor-deficient mice show no major perturbation of hematopoiesis but develop a characteristic pulmonary pathology. Proc Natl Acad Sci U S A 1994; 91:5592-6. [PMID: 8202532 PMCID: PMC44042 DOI: 10.1073/pnas.91.12.5592] [Citation(s) in RCA: 628] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Mice homozygous for a disrupted granulocyte/macrophage colony-stimulating factor (GM-CSF) gene develop normally and show no major perturbation of hematopoiesis up to 12 weeks of age. While most GM-CSF-deficient mice are superficially healthy and fertile, all develop abnormal lungs. There is extensive peribronchovascular infiltration with lymphocytes, predominantly B cells. Alveoli contain granular eosinophilic material and lamellar bodies, indicative of surfactant accumulation. There are numerous large intraalveolar phagocytic macrophages. Some mice have subclinical lung infections involving bacterial or fungal organisms, occasionally with focal areas of acute purulent inflammation or lobar pneumonia. Some features of this pathology resemble the human disorder alveolar proteinosis. These observations indicate that GM-CSF is not essential for the maintenance of normal levels of the major types of mature hematopoietic cells and their precursors in blood, marrow, and spleen. However, they implicate GM-CSF as essential for normal pulmonary physiology and resistance to local infection.
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81
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Ernst M, Gearing DP, Dunn AR. Functional and biochemical association of Hck with the LIF/IL-6 receptor signal transducing subunit gp130 in embryonic stem cells. EMBO J 1994; 13:1574-84. [PMID: 8156996 PMCID: PMC394987 DOI: 10.1002/j.1460-2075.1994.tb06420.x] [Citation(s) in RCA: 126] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The role played by the Src-related tyrosine kinase, Hck, in embryonic stem (ES) cell differentiation was investigated by replacing a conserved C-terminally located tyrosine with phenylalanine by gene targeting. Targeted ES cells display a 7- to 9-fold elevation in constitutive Hck kinase activity and require approximately 15 times less leukaemia inhibitory factor (LIF) than parental ES cells to maintain their stem cell character in vitro. We also demonstrate a rapid and transient increase in Hck tyrosine kinase activity in parental ES cells stimulated by LIF and, finally, show that Hck is physically associated with gp130, an affinity converter and signal transducing component of the LIF receptor. Thus, these results provide biological and biochemical evidence that Hck participates in signal transduction from the LIF receptor.
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Mann GB, Fowler KJ, Grail D, Dunn AR. Identification of germ-line chimaeras by polymerase chain reaction and isoenzyme analysis of mouse spermatozoa. JOURNAL OF REPRODUCTION AND FERTILITY 1993; 99:505-12. [PMID: 8107033 DOI: 10.1530/jrf.0.0990505] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In this study a rapid, simple and inexpensive procedure is described which allows potential germ-line male mice to be identified with confidence. Spermatozoa recovered by uterine washing following mating with normal female mice was analysed in two ways. First, the patterns of expression of the different isoforms of glucose phosphate isomerase were determined. Since the glucose phosphate isomerase isoforms expressed in embryo stem (ES) cell lines are frequently different from those associated with the host blastocyst, it is possible to determine the proportion of spermatozoa produced by an individual animal that was of ES cell or host-blastocyst origin. Second, DNA of spermatozoa was subjected to polymerase chain reaction (PCR) analysis using primers with specificity for the targeted mutation in the ES cells. The PCR analysis was particularly valuable in identifying germ cell chimaeras in which the contribution of ES-derived spermatozoa was significantly less than that specified by the host blastocyst.
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83
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Fowler KJ, Mann GB, Dunn AR. Linkage of the murine transforming growth factor alpha gene with Igk, Ly-2, and Fabp1 on chromosome 6. Genomics 1993; 16:782-4. [PMID: 8100806 DOI: 10.1006/geno.1993.1268] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
TGF alpha is a mitogenic polypeptide found in the conditioned media of transformed cell lines as well as in various solid tumors. Although its physiological role in normal tissues is uncertain, the autocrine action of TGF alpha on the EGF receptor is postulated to play a role in tumorigenesis. To explore the possibility that pre-existing mouse mutants might have concordance with the mouse TGF alpha locus (Tgfa) we sought to establish the chromosomal localization of the murine TGF alpha gene. Using Southern analysis we have detected NcoI and PvuII RFLPs in the TGF alpha gene of progenitor RI mouse strains. These RFLPs have been used to analyze four different RI sets of DNA and to assign Tgfa to the 35-cM region of chromosome 6. Linkage has been established and the data suggest that the distance between Igk and wa-1 anchor loci may be less than 8 cM and that the gene order for the proximal to mid region of mouse chromosome 6 may be: Ggc-Xmmv27-[Brp-1, Lvp-1, Ms6-4]-[Igk, Ly2, Ly3 Odc-rs5, Rn7s-6, Fabp1]-[Tgfa/wa-1]-IL5-R. Homology of synteny has been further defined between the proximal region of mouse chromosome 6 and with the 2p13-p11 region of human chromosome 2 encompassing TGFA, IGK, CD8A, and FABP1.
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84
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Clay FJ, McEwen SJ, Bertoncello I, Wilks AF, Dunn AR. Identification and cloning of a protein kinase-encoding mouse gene, Plk, related to the polo gene of Drosophila. Proc Natl Acad Sci U S A 1993; 90:4882-6. [PMID: 8099445 PMCID: PMC46617 DOI: 10.1073/pnas.90.11.4882] [Citation(s) in RCA: 123] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
We have determined the nucleotide sequence of a cDNA encoding a protein kinase that is closely related to the enzyme encoded by the Drosophila melanogaster mutant polo and that we have designated Plk (polo-like kinase). Plk is also related to the products of the Saccharomyces cerevisiae cell cycle gene MSD2 (CDC5) and the recently described early growth response gene Snk. Together, Plk, polo, Snk, and MSD2 define a subfamily of serine/threonine protein kinases. Plk is expressed at high levels in a number of fetal and newborn mouse tissues but is not expressed in the corresponding adult organs. With the exception of adult hemopoietic tissues, the only adult tissues in which we could detect Plk expression were ovaries and testes. Taken together, the patterns of Plk expression suggest an association with proliferating cells. Since polo is required for mitosis in Drosophila it is possible that Plk is involved in some aspect of cell cycle regulation in mammalian cells.
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85
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Mann GB, Fowler KJ, Gabriel A, Nice EC, Williams RL, Dunn AR. Mice with a null mutation of the TGF alpha gene have abnormal skin architecture, wavy hair, and curly whiskers and often develop corneal inflammation. Cell 1993; 73:249-61. [PMID: 8477444 DOI: 10.1016/0092-8674(93)90227-h] [Citation(s) in RCA: 460] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Mice homozygous for a disrupted transforming growth factor alpha (TGF alpha) gene are healthy and fertile, although some older mice show evidence of corneal inflammation. In contrast with TGF alpha +/- and +/+ animals, TGF alpha -/- mice have a pronounced waviness of the coat. Histological examination of the skin from TGF alpha -/- mice reveals a dramatic derangement of hair follicles. Mice with a disrupted TGF alpha gene also have curly whiskers, first evident on the day of birth. The phenotype of TGF alpha -/- mice is remarkably similar to that of the mouse mutant waved-1 (wa-1). Offspring resulting from crosses between TGF alpha -/- and wa-1 mice display the curly whisker-coat phenotype, indicating that the basis of the wa-1 phenotype is a mutation in the TGF alpha gene. These observations suggest that TGF alpha plays a pivotal role in determining skin architecture and in regulating hair development.
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86
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Boulet I, Ralph S, Stanley E, Lock P, Dunn AR, Green SP, Phillips WA. Lipopolysaccharide- and interferon-gamma-induced expression of hck and lyn tyrosine kinases in murine bone marrow-derived macrophages. Oncogene 1992; 7:703-10. [PMID: 1373483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
We have examined the role of tyrosine phosphorylation during the course of macrophage activation. Initial experiments indicated that vanadate, a known phosphotyrosine phosphatase inhibitor, enhanced the phorbol 12-myristate 13-acetate (PMA)-triggered respiratory burst and potentiated the priming effects of bacterial lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma), suggesting that tyrosine phosphorylation may be important in these end cell functions. As src-related kinases have been implicated in the activation of cells of other haemopoietic lineages, we examined the relationship between the activity of two such kinases, hck and lyn, and priming of the respiratory burst. We found that the level of hck and lyn is increased following exposure of bone marrow-derived macrophages (BMM) to LPS or IFN-gamma. The induction of both of these kinases follows similar kinetics with maximal activity occurring at 24-48 h. Interestingly, the kinetics of induction of hck and lyn kinase activity in BMM demonstrated a close temporal relationship with the priming effects of LPS and IFN-gamma on the macrophage respiratory burst. Collectively, these observations raise the possibility that modulation of expression of hck and lyn is involved in the regulation of the respiratory burst.
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87
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Lang RA, Cuthbertson RA, Dunn AR. TNF alpha, IL-1 alpha and bFGF are implicated in the complex disease of GM-CSF transgenic mice. Growth Factors 1992; 6:131-8. [PMID: 1586489 DOI: 10.3109/08977199209011016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Transgenic mice aberrantly expressing the granulocyte-macrophage colony stimulating factor (GM-CSF) gene develop an unusual syndrome of blindness, tissue damage and wasting which is associated with accumulations of hemopoietic cells. In order to further characterize this disease state, we have used messenger RNA detection techniques to show that the genes for tumor necrosis factor (TNF alpha), interleukin-1 alpha (IL-1 alpha) and basic fibroblast growth factor (bFGF) are expressed at abnormally high levels in both macrophages and granulocytes in transgenic mice. Furthermore, since these cell types also express the GM-CSF transgene, it is likely that they are autocrine stimulated by GM-CSF. These observations raise the possibilities that, first, the expression of tumor necrosis factor alpha, interleukin-1 alpha and basic fibroblast growth factor in hemopoietic cells is a direct consequence of their autostimulation by GM-CSF, and second, that these cytokines may be responsible for some aspects of the transgenic mouse disease.
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88
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Lock P, Ralph S, Stanley E, Boulet I, Ramsay R, Dunn AR. Two isoforms of murine hck, generated by utilization of alternative translational initiation codons, exhibit different patterns of subcellular localization. Mol Cell Biol 1991; 11:4363-70. [PMID: 1875927 PMCID: PMC361298 DOI: 10.1128/mcb.11.9.4363-4370.1991] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Mammalian hck, a member of the src family of tyrosine kinases, is expressed predominantly in cells of the myeloid and B-lymphoid lineages. Using mutational analysis, we have investigated the molecular basis of two immunoreactive forms of murine hck of 56 and 59 kDa found in numerous hemopoietic cell types. Our results indicate that translation of murine p59hck initiates from a CTG codon located 21 codons 5' of an ATG that is utilized to generate p56hck. We provide evidence that two human hck isoforms are generated by the same mechanism. Subcellular fractionation studies reveal that while p59hck and p56hck are associated with membranes of various murine B-lymphoid and myeloid cell lines, p59hck alone is also located in the cytosol. In contrast to membrane-associated p59hck, which is metabolically labeled with [3H]myristic acid and exhibits amphiphilic properties in Triton X-114 detergent, cytosolic p59hck is hydrophilic, suggesting that it is not acylated. Possible mechanisms are proposed to account for these observations.
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89
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Stanley E, Ralph S, McEwen S, Boulet I, Holtzman DA, Lock P, Dunn AR. Alternatively spliced murine lyn mRNAs encode distinct proteins. Mol Cell Biol 1991; 11:3399-406. [PMID: 1710766 PMCID: PMC361064 DOI: 10.1128/mcb.11.7.3399-3406.1991] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Two lyn proteins of 56 and 53 kDa have been observed in immunoprecipitates from a variety of murine and human cell lines and tissues. We report the cloning and nucleotide sequence of two distinct murine lyn cDNAs isolated from an FDC-P1 cDNA library. One of the cDNAs, designated lyn11, encodes a protein of 56 kDa which shares 96% similarity with human lyn. The other cDNA, designated lyn12, encodes a protein of 53 kDa. The proteins differ in the presence or absence of a 21-amino-acid sequence located 24 amino acids C terminal of the translational initiation codon. Using RNase protection analysis, we have identified mRNAs corresponding to both cDNAs in murine cell lines and tissues. Sequence analysis of murine genomic clones suggests that the distinct mRNAs are alternatively spliced transcripts derived from a single gene. Expression of both cDNAs in COS cells leads to the production of lyn proteins with the same molecular weight as the two forms of lyn proteins immunoprecipitated from extracts of FDC-P1 cells and mouse spleen. Subcellular fractionation studies and Western immunoblotting analysis suggest that both isoforms of lyn are membrane associated. The association of both lyn isoforms with the membrane fraction supports the notion that lyn, like other src-related kinases, may interact with the intracellular domain of cell surface receptors.
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90
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Lock P, Stanley E, Holtzman DA, Dunn AR. Functional analysis and nucleotide sequence of the promoter region of the murine hck gene. Mol Cell Biol 1990; 10:4603-11. [PMID: 2388619 PMCID: PMC361049 DOI: 10.1128/mcb.10.9.4603-4611.1990] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The structure and function of the promoter region and exon 1 of the murine hck gene have been characterized in detail. RNase protection analysis has established that hck transcripts initiate from heterogeneous start sites located within the hck gene. Fusion gene constructs containing hck 5'-flanking sequences and the bacterial Neor gene have been introduced into the hematopoietic cell lines FDC-P1 and WEHI-265 by using a self-inactivating retroviral vector. The transcriptional start sites of the fusion gene are essentially identical to those of the endogenous hck gene. Analysis of infected WEHI-265 cell lines treated with bacterial lipopolysaccharide (LPS) reveals a 3- to 5-fold elevation in the levels of endogenous hck mRNA and a 1.4- to 2.6-fold increase in the level of Neor fusion gene transcripts, indicating that hck 5'-flanking sequences are capable of conferring LPS responsiveness on the Neor gene. The 5'-flanking region of the hck gene contains sequences similar to an element which is thought to be involved in the LPS responsiveness of the class II major histocompatibility gene A alpha k. A subset of these sequences are also found in the 5'-flanking regions of other LPS-responsive genes. Moreover, this motif is related to the consensus binding sequence of NF-kappa B, a transcription factor which is known to be regulated by LPS.
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91
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Sobieszczuk PW, Gonda TJ, Dunn AR. Structure and biological activity of the transcriptional initiation sequences of the murine c-myb oncogene. Nucleic Acids Res 1989; 17:9593-611. [PMID: 2481264 PMCID: PMC335200 DOI: 10.1093/nar/17.23.9593] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
To study the control mechanism(s) that govern the transcription of c-myb, genomic clones corresponding to the 5' region of the murine c-myb gene have been isolated and characterized structurally and functionally. Primer extension and nuclease protection analysis have revealed the presence of multiple transcriptional initiation sites, that are utilized in several hemopoietic cell lines (WEHI3B(D+). FDC-P1 and RB22.2). Some of the sites are used in all cell lines but others are unique; all are located in a region of the c-myb gene that is G-C rich, contains a number of potential Sp1 binding sites and lacks classical promoter consensus sequences. Experiments in which well characterized promoters controlling expression of a reporter gene have been replaced by fragments of c-myb DNA (including the observed cap sites) were performed in an attempt to demonstrate promoter activity in various cell types. It was shown that a region of the c-myb gene (approximately 1.0 kbp upstream from the splice donor site of the first exon) contains a weak promoter that has a low level of transcriptional activity in hemopoietic as well as in fibroblastic cells. These results support the suggestion that c-myb expression is not regulated primarily at the level of initiation of transcription.
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92
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Wilks AF, Kurban RR, Dunn AR. Direct demonstration of an autocrine mechanism in EMS-induced, tumorigenic mutants of the growth factor-dependent hemopoietic cell line, FDC-P1. Growth Factors 1989; 2:31-42. [PMID: 2699568 DOI: 10.3109/08977198909069079] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A growth factor-dependent hemopoietic cell-line, FDC-P1, was treated with a chemical mutagen, EMS, and a number of growth factor-independent variants isolated. Six lines have been extensively analyzed with respect to their growth kinetics, morphology, karyotype, tumorigenicity, and hemopoietic growth factor production. Four lines produced at least one growth factor, subsequently demonstrated to be GM-CSF, while two lines showed no evidence of hemopoietic growth factor production. The observation that the autonomous proliferation of those EMS-derived cell lines that produced GM-CSF can be inhibited by incubation in growth media containing 10-50 microM anti-sense GM-CSF oligonucleotides demonstrated directly that the autonomous behavior of these cells is based on an autocrine mechanism. The induction of the expression of the GM-CSF gene represents a rare class of EMS-induced mutants, and is strongly suggestive of repressor inactivation rather than promoter activation.
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93
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Gough NM, King JA, Dunn AR. An mRNA sharing sequences with a variant granulocyte-macrophage colony stimulating factor cDNA clone. Nucleic Acids Res 1987; 15:10584. [PMID: 3320970 PMCID: PMC339965 DOI: 10.1093/nar/15.24.10584] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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94
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Metcalf D, Roberts TM, Cherington V, Dunn AR. The in vitro behavior of hemopoietic cells transformed by polyoma middle T antigen parallels that of primary human myeloid leukemic cells. EMBO J 1987; 6:3703-9. [PMID: 3501372 PMCID: PMC553840 DOI: 10.1002/j.1460-2075.1987.tb02704.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
A retrovirus encoding polyoma middle T antigen has been used to infect a murine hemopoietic cell line (FDC-P1) dependent on either granulocyte-macrophage colony-stimulating factor (GM-CSF) or multipotential colony-stimulating factor (Multi-CSF). A number of cell lines have been established on the basis of their initial ability to proliferate in the absence of added colony-stimulating factor (CSF). The transformed lines display one of three patterns of growth in vitro: those able to grow fully autonomously; those whose proliferation depends on cell density; and those displaying dependence on added CSF regardless cell density. This latter class of cells are reminiscent of the majority of primary myeloid leukemic cells. Unlike parental FDC-P1 cells, all three classes of transformed cells are leukemogenic in syngeneic mice; moreover, they produce variable amounts of GM-CSF which we believe underlies their neoplastic behavior.
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95
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96
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Holtzman DA, Cook WD, Dunn AR. Isolation and sequence of a cDNA corresponding to a src-related gene expressed in murine hemopoietic cells. Proc Natl Acad Sci U S A 1987; 84:8325-9. [PMID: 3317404 PMCID: PMC299535 DOI: 10.1073/pnas.84.23.8325] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
We have isolated a murine cDNA that shares extensive homology with genes encoding the src (Rous sarcoma virus oncogene)-related family of protein-tyrosine kinases. The cDNA includes an open reading frame of 1509 base pairs, and conceptual translation predicts a protein of 56 kDa. Blot-hybridization analysis indicates that this src-related gene is expressed in normal macrophages and in cell lines representing both the myeloid and lymphoid B-cell lineages and, accordingly, is designated "bmk" (B cell/myeloid kinase). In addition, bmk mRNA levels increase following the induced differentiation of the murine myelomonocytic leukemic cell line WEHI-3B.
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97
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Dunn AR. The colony stimulating factors in normal haemopoiesis and leukaemia. Haematologica 1987; 72:81-4. [PMID: 3127304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
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98
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Lingelbach KR, Graf LJ, Dunn AR, Hoogenraad NJ. Effect of deletions within the leader peptide of pre-ornithine transcarbamylase on mitochondrial import. EUROPEAN JOURNAL OF BIOCHEMISTRY 1986; 161:19-23. [PMID: 3780735 DOI: 10.1111/j.1432-1033.1986.tb10119.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The uptake of the cytoplasmically synthesized mammalian enzyme, ornithine transcarbamylase, into mitochondria is directed by an N-terminal peptide of 32 amino acids. We have investigated some of the structural requirements for the import of the enzyme from rat liver into isolated mitochondria and into mitochondria of COS cells transfected with cDNA encoding the precursor form of ornithine transcarbamylase. Deletion of 21 amino acids from the N terminus of the leader peptide blocked the import of the precursor; deletion of 5 amino acids at positions 15-19 from the N terminus of the leader peptide had no deleterious effect on the import of the enzyme, nor on the processing and assembly of subunits in mitochondria. The region deleted contained three of eight basic residues in the leader peptide suggesting that specific structural elements containing basic residues, rather than the general basic nature of the leader, may be involved in mitochondrial import.
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Lang RA, Metcalf D, Gough NM, Dunn AR, Gonda TJ. Expression of a hemopoietic growth factor cDNA in a factor-dependent cell line results in autonomous growth and tumorigenicity. Cell 1985; 43:531-42. [PMID: 3878229 DOI: 10.1016/0092-8674(85)90182-5] [Citation(s) in RCA: 220] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Production of a growth factor by a cell that responds to this factor has been termed "autocrine" stimulation of proliferation. Considerable experimental data have suggested that tumor cells often exhibit autocrine growth stimulation and that this may contribute to the process of malignant transformation. To experimentally approach the relationship of autocrine growth stimulation to the malignant transformation of hemopoietic cells, we have used a retroviral vector to express sequences encoding a hemopoietic growth factor, granulocyte-macrophage colony stimulating factor (GM-CSF) in a factor-dependent murine cell line (FDC-P1). Virally infected cells synthesized and secreted GM-CSF, grew independently of exogenous CSF, and--unlike the parental FDC-P1 cells--produced tumors in syngeneic mice. We have thus experimentally induced autocrine growth regulation in a factor-dependent hemopoietic cell line and have shown that this results in tumorigenicity.
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Stanley E, Metcalf D, Sobieszczuk P, Gough NM, Dunn AR. The structure and expression of the murine gene encoding granulocyte-macrophage colony stimulating factor: evidence for utilisation of alternative promoters. EMBO J 1985; 4:2569-73. [PMID: 3876931 PMCID: PMC554545 DOI: 10.1002/j.1460-2075.1985.tb03972.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Two overlapping genomic clones containing the murine granulocyte-macrophage colony stimulating factor (GM-CSF) gene have been isolated. On the basis of transfection experiments, we have established that a 9-kb BamHI fragment from one of these recombinants encodes biologically active GM-CSF. As deduced from nucleotide sequence analysis, the GM-CSF gene comprises four exons encompassing 2.5 kb of genomic DNA. Primer extension analysis of GM-CSF mRNA identifies a transcriptional initiation site 35 bp upstream of a single translational initiation codon in-frame with the GM-CSF coding sequences and 28 bp downstream of a TATA promoter consensus sequence. Pre-GM-CSF molecules encoded by mRNAs originating from this promoter would include a hydrophobic leader sequence typical for a secreted protein. Intriguingly, sequences present at the 5' end of a GM-CSF cDNA clone previously isolated in our laboratory are not contained within either of the genomic clones and must therefore be transcribed from a promoter located at least 10 kb 5' of the main body of the gene. mRNAs transcribed from this alternative upstream promoter possess an additional initiating codon and potentially encode a pre-GM-CSF polypeptide with an atypical NH2-terminal leader peptide. Comparison of the nucleotide sequence of the GM-CSF gene with that of other haemopoietic growth factor genes has revealed a common decanucleotide (5'-GPuGPuTTPyCAPy-3') within their respective 5'-flanking regions which may be involved in their co-ordinate regulation.
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