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.
Division of Molecular and Developmental Biology, Mount Sinai Hospital, Toronto, Ontario, Canada.
D J
DJ
Dumont
G J
GJ
Gradwohl
G H
GH
Fong
R
R
Auerbach
M L
ML
Breitman
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