title: Ephrin-B2 is a candidate ligand for the Eph receptor, EphB6.
abstract: 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.
authors.affiliation: Department of Immunology, Institute for Cancer Research, The Norwegian Radium Hospital, Montebello, N-0310, Oslo, Norway.
authors.forename: E
authors.initials: E
authors.lastname: Munthe
authors.forename: E
authors.initials: E
authors.lastname: Rian
authors.forename: T
authors.initials: T
authors.lastname: Holien
authors.forename: A
authors.initials: A
authors.lastname: Rasmussen
authors.forename: F O
authors.initials: FO
authors.lastname: Levy
authors.forename: H
authors.initials: H
authors.lastname: Aasheim
mesh_terms: 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
chemical_list: 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