Fms-like tyrosine kinase 3 catalytic domain can transduce a proliferative signal in FDC-P1 cells that is qualitatively similar to the signal delivered by c-Fms.
A full length clone of murine fms-like tyrosine kinase 3 [flt3, also known as fetal liver kinase 2 (flk2)] was constructed from sequences obtained from a brain complementary DNA (cDNA) library and from cDNA prepared from the cell line Tikaut. In the absence of a ligand to study the function of Flt3, a chimeric molecule was constructed comprising the extracellular domain of murine c-Fms and the transmembrane and cytoplasmic domains of Flt3. A plasmid encoding the chimeric receptor was cotransfected along with a plasmid conferring neomycin resistance into FDC-P1 cells that do not normally express c-fms or flt3 and require granulocyte-macrophage colony-stimulating factor (GM-CSF) or interleukin 3 for growth. Two types of clones were obtained following selection in GM-CSF and G418. Two of seven clones had the capacity for M-CSF-dependent colony formation in semisolid medium, indicating that the cytoplasmic domain of Flt3 can transduce a proliferative signal. From the remaining clones, M-CSF-dependent clonogenic cells could be selected by prior bulk liquid culture in M-CSF. It has been shown previously that the GM-CSF-dependent proliferative capacity is strongly inhibited by M-CSF in FDC-P1 cells engineered to express full length c-fms. This phenomenon was also observed with FD/fms-flt3 cells that were clonogenic in M-CSF. Stimulation of FD/fms or FD/fms-flt3 cells in liquid culture by M-CSF caused differentiation of a small proportion of cells along the myelomonocytic pathway which was enhanced by the combination of M-CSF and GM-CSF.(ABSTRACT TRUNCATED AT 250 WORDS)
Rossner
M T
MT
Walter and Eliza Hall Institute of Medical Research, Royal Melbourne Hospital, Parkville, Victoria, Australia.
McArthur
G A
GA
Allen
J D
JD
Metcalf
D
D
D000818:Animals; D001923:Brain Chemistry; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division; D002460:Cell Line; D003001:Cloning, Molecular; D016236:Genes, fms / Q000235:genetics; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D051379:Mice; D009928:Organ Specificity; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000502:physiology*; D012333:RNA, Messenger / Q000096:biosynthesis; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000502:physiology*; D016186:Receptor, Macrophage Colony-Stimulating Factor / Q000235:genetics / Q000502:physiology*; D011956:Receptors, Cell Surface / Q000235:genetics / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D017422:Sequence Analysis, DNA; D015398:Signal Transduction / Q000502:physiology*; D014158:Transcription, Genetic; D051941:fms-Like Tyrosine Kinase 3
D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins; D016173:Macrophage Colony-Stimulating Factor; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; C497971:Flt3 protein, mouse; D020794:Receptor Protein-Tyrosine Kinases; D016186:Receptor, Macrophage Colony-Stimulating Factor; D051941:fms-Like Tyrosine Kinase 3