Molecular characterization of a family of ligands for eph-related tyrosine kinase receptors.
A family of tyrosine kinase receptors related to the product of the eph gene has been described recently. One of these receptors, elk, has been shown to be expressed only in brain and testes. Using a direct expression cloning technique, a ligand for the elk receptor has been isolated by screening a human placenta cDNA library with a fusion protein containing the extracellular domain of the receptor. This isolated cDNA encodes a transmembrane protein. While the sequence of the ligand cDNA is unique, it is related to a previously described sequence known as B61. Northern blot analysis of human tissue mRNA showed that the elk ligand's mRNA is 3.5 kb long and is found in placenta, heart, lung, liver, skeletal muscle, kidney and pancreas. Southern blot analysis showed that the gene is highly conserved in a wide variety of species. Both elk ligand and B61 mRNAs are inducible by tumour necrosis factor in human umbilical vein endothelial cells. In addition, both proteins show promiscuity in binding to the elk and the related hek receptors. Since these two ligand sequences are similar, and since elk and hek are members of a larger family of eph-related receptor molecules, we refer to these ligands as LERKs (ligands for eph-related kinases).
Beckmann
M P
MP
Immunex Research and Development Corporation, Seattle, WA 98101.
Cerretti
D P
DP
Baum
P
P
Vanden Bos
T
T
James
L
L
Farrah
T
T
Kozlosky
C
C
Hollingsworth
T
T
Shilling
H
H
Maraskovsky
E
E
D000595:Amino Acid Sequence; D001483:Base Sequence; D004268:DNA-Binding Proteins; D004730:Endothelium, Vascular / Q000502:physiology; D036382:Ephrin-A1; D036387:Ephrin-B1; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D011485:Protein Binding; D011506:Proteins / Q000235:genetics* / Q000378:metabolism*; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger / Q000032:analysis; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D036121:Receptor, EphA3; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015682:Retroviridae Proteins, Oncogenic / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D014018:Tissue Distribution; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D014471:Umbilical Veins / Q000502:physiology; D050807:ets-Domain Protein Elk-1
D004268:DNA-Binding Proteins; D036382:Ephrin-A1; D036387:Ephrin-B1; D011506:Proteins; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D015682:Retroviridae Proteins, Oncogenic; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D050807:ets-Domain Protein Elk-1; D020794:Receptor Protein-Tyrosine Kinases; D036121:Receptor, EphA3