Ephrin-B2 is a candidate ligand for the Eph receptor, EphB6.
No ligand has hitherto been designated for the Eph receptor tyrosine kinase family member, EphB6. Here, expression of an EphB6 ligand in the pro-B leukemic cell line, Reh, is demonstrated by binding of soluble EphB6-Fc fusion protein to the Reh cells. The ligand belongs to the subgroup of membrane spanning ligands, as suggested by the fact that phosphatidylinositol-specific phospholipase C treatment did not abrogate binding of EphB6-Fc. Two transmembrane Eph receptor ligands, ephrin-B1 and ephrin-B2, were identified in Reh cells. Analysis of EphB6-Fc fusion protein binding to ephrin-B1 or ephrin-B2 transfected COS cells revealed a high-affinity saturable binding between EphB6-Fc and ephrin-B2, but not with ephrin-B1. In mice, EphB6 has previously been shown to be expressed in thymus. Here, we show expression of EphB6 in human thymus, as well as the expression of ephrin-B2 in both human and mouse thymus. We conclude that ephrin-B2 may be a physiological ligand for the EphB6 receptor.
Munthe
E
E
Department of Immunology, Institute for Cancer Research, The Norwegian Radium Hospital, Montebello, N-0310, Oslo, Norway.
Rian
E
E
Holien
T
T
Rasmussen
A
A
Levy
F O
FO
Aasheim
H
H
D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002460:Cell Line; D017931:DNA Primers / Q000235:genetics; D036388:Ephrin-B2; D006801:Humans; D008024:Ligands; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D054801:Phosphoinositide Phospholipase C; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013950:Thymus Gland / Q000378:metabolism; D014018:Tissue Distribution; D014162:Transfection; D010738:Type C Phospholipases / Q000378:metabolism
D017931:DNA Primers; D036388:Ephrin-B2; D008024:Ligands; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; D020794:Receptor Protein-Tyrosine Kinases; D010738:Type C Phospholipases; D054801:Phosphoinositide Phospholipase C; D043265:Phosphatidylinositol Diacylglycerol-Lyase