Ligands for the receptor tyrosine kinases hek and elk: isolation of cDNAs encoding a family of proteins.
Hek is a member of the eph subfamily of receptor tyrosine kinases whose members include elk, hek2, sek, eph and eck among others. Using a soluble form of hek consisting of the extracellular region of the receptor fused to the Fc domain of human IgG1 and an expression cloning strategy, we have isolated two different but related cDNAs from the human T-lymphoma line HSB-2 that encode ligands for hek. The cDNAs encode proteins of 238 and 201 amino acids (44% amino acid identity) that are anchored to the membrane by glycosylphosphatidylinositol (GPI)-linkage. The proteins encoded by these cDNAs are bound by hek with affinity constants of 2 x 10(8) M-1. These proteins also bind the elk tyrosine kinase receptor. These cDNAs are related to other cDNAs that we have recently isolated from a human placental library that encode ligands for both hek and elk and define an emerging family of ligands for eph-related kinases (LERKs).
Department of Gene Expression, Immunex Research and Development Corporation, Seattle, Washington 98101.
C J
CJ
Kozlosky
E
E
Maraskovsky
J T
JT
McGrew
T
T
VandenBos
M
M
Teepe
S D
SD
Lyman
S
S
Srinivasan
F A
FA
Fletcher
R B
RB
Gayle
D P
DP
Cerretti
D000595:Amino Acid Sequence; D001483:Base Sequence; D018076:DNA, Complementary; D036384:Ephrin-A3; D036385:Ephrin-A4; D036387:Ephrin-B1; D017261:Glycosylphosphatidylinositols / Q000378:metabolism; D008024:Ligands; D008565:Membrane Proteins / Q000737:chemistry; D008969:Molecular Sequence Data; D011506:Proteins / Q000737:chemistry; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics*; D036223:Receptor, EphB3; D011994:Recombinant Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
D018076:DNA, Complementary; D036384:Ephrin-A3; D036385:Ephrin-A4; D036387:Ephrin-B1; D017261:Glycosylphosphatidylinositols; D008024:Ligands; D008565:Membrane Proteins; D011506:Proteins; D011994:Recombinant Proteins; D020794:Receptor Protein-Tyrosine Kinases; D036223:Receptor, EphB3