Biochemical characterization and analysis of the transforming potential of the FLT3/FLK2 receptor tyrosine kinase.
We recently cloned an additional member of the receptor type tyrosine kinase class III. This new gene, called Flt3 by our group [Rosnet, O., Matteï, M.G., Marchetto, S. & Birnbaum, D. (1991). Genomics, 9, 380-385; Rosnet, O., Marchetto, S., deLapeyriere, O. & Birnbaum, D. (1991). Oncogene, 6, 1641-1650] and Flk2 by others [Matthews, W., Jordan, C.T., Wieg, G.W., Pardoll, D. & Lemischka, I.R. (1991). Cell, 65, 1143-1152] is strongly related to the important developmental genes Kit, Fms and Pdgfr. The murine 3.2-kb full-length cDNA, when introduced into COS-1 cells, shows the expression of two polypeptides with apparent molecular weights of 155 kDa and 132 kDa. Treatment of cells with N-linked glycosylation inhibitors results in the expression of a 110-kDa protein. We have shown that FLT3 contains an intrinsic tyrosine kinase activity. A point mutation in a highly conserved residue within the phosphoryltransferase domain inactivates the catalytic function of this receptor, whereas activation by way of a chimeric molecule between the ligand-binding domain of colony-stimulating factor type 1 (CSF-1) receptor (CSF-1R) and the kinase domain of FLT3 results, in the presence of CSF-1, in the development of the transforming activity of this receptor as shown by anchorage-independent cell growth. Finally, expression analysis of the FLT3 protein shows that, in addition to the hematopoietic system, FLT3 is strongly expressed in neural, gonadal, hepatic and placental tissues in the mouse.
Molecular Hematology Laboratory, Unité 119 INSERM, Marseille, France.
N
N
Maroc
R
R
Rottapel
O
O
Rosnet
S
S
Marchetto
C
C
Lavezzi
P
P
Mannoni
D
D
Birnbaum
P
P
Dubreuil
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002471:Cell Transformation, Neoplastic; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D004252:DNA Mutational Analysis; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D011505:Protein-Tyrosine Kinases / Q000737:chemistry* / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000737:chemistry* / Q000378:metabolism; D051381:Rats; D020794:Receptor Protein-Tyrosine Kinases; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D014018:Tissue Distribution; D014162:Transfection; D051941:fms-Like Tyrosine Kinase 3
D008562:Membrane Glycoproteins; D009838:Oligodeoxyribonucleotides; D011518:Proto-Oncogene Proteins; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; C497971:Flt3 protein, mouse; D011505:Protein-Tyrosine Kinases; D020794:Receptor Protein-Tyrosine Kinases; D051941:fms-Like Tyrosine Kinase 3