The endothelial-specific receptor tyrosine kinase, tek, is a member of a new subfamily of receptors.
We have cloned a 4.2-kb murine cDNA encoding the Tek receptor tyrosine kinase (RTK), which is expressed in endothelial cells and their progenitors. The 1122-residue protein contains an extracellular domain comprising three fibronectin type III repeats fused to two immunoglobulin-like loops that are in turn separated by three epidermal growth factor-like repeats. The association of these different structural motifs and their characteristic arrangement in the Tek extracellular domain has been reported for only one other RTK, Tie, an endothelial-specific RTK of human origin. We show here that Tek and Tie are encoded by distinct genes and that, together, these receptors define a new subfamily of RTKs. In addition, we demonstrate that the tek cDNA, when introduced into COS cells, encodes a product of 140 kDa and that this protein and/or tek transcripts are detectable in highly vascularized embryonic tissues and in some, but not all, cell lines of endothelial origin.
Dumont
D J
DJ
Division of Molecular and Developmental Biology, Mount Sinai Hospital, Toronto, Ontario, Canada.
Gradwohl
G J
GJ
Fong
G H
GH
Auerbach
R
R
Breitman
M L
ML
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry; D004730:Endothelium, Vascular / Q000201:enzymology*; D015870:Gene Expression; D051379:Mice; D008969:Molecular Sequence Data; D011505:Protein-Tyrosine Kinases / Q000235:genetics*; D011506:Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics*; D011956:Receptors, Cell Surface / Q000235:genetics*; D040262:Receptors, Vascular Endothelial Growth Factor; D017386:Sequence Homology, Amino Acid
D011506:Proteins; D011956:Receptors, Cell Surface; D004247:DNA; D011505:Protein-Tyrosine Kinases; D040262:Receptors, Vascular Endothelial Growth Factor