title: B61 is a ligand for the ECK receptor protein-tyrosine kinase.
abstract: A protein ligand for the ECK receptor protein-tyrosine kinase has been isolated by using the extracellular domain (ECK-X) of the receptor as an affinity reagent. Initially, concentrated cell culture supernatants were screened for receptor binding activity using immobilized ECK-X in a surface plasmon resonance detection system. Subsequently, supernatants from selected cell lines were fractionated directly by receptor affinity chromatography, resulting in the single-step purification of B61, a protein previously identified as the product of an early response gene induced by tumour necrosis factor-alpha. We report here that recombinant B61 induces autophosphorylation of ECK in intact cells, consistent with B61 being an authentic ligand for ECK. ECK is a member of a large orphan receptor protein-tyrosine kinase family headed by EPH, and we suggest that ligands for other members of this family will be related to B61, and can be isolated in the same way.
authors.affiliation: Amgen Inc., Thousand Oaks, California 91320-1789.
authors.forename: T D
authors.initials: TD
authors.lastname: Bartley
authors.forename: R W
authors.initials: RW
authors.lastname: Hunt
authors.forename: A A
authors.initials: AA
authors.lastname: Welcher
authors.forename: W J
authors.initials: WJ
authors.lastname: Boyle
authors.forename: V P
authors.initials: VP
authors.lastname: Parker
authors.forename: R A
authors.initials: RA
authors.lastname: Lindberg
authors.forename: H S
authors.initials: HS
authors.lastname: Lu
authors.forename: A M
authors.initials: AM
authors.lastname: Colombero
authors.forename: R L
authors.initials: RL
authors.lastname: Elliott
authors.forename: B A
authors.initials: BA
authors.lastname: Guthrie
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D002460:Cell Line; D003001:Cloning, Molecular; D006224:Cricetinae; D036382:Ephrin-A1; D006801:Humans; D008024:Ligands; D008565:Membrane Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D036104:Receptor, EphA2; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: D036382:Ephrin-A1; D008024:Ligands; D008565:Membrane Proteins; D011506:Proteins; D011994:Recombinant Proteins; D011505:Protein-Tyrosine Kinases; D036104:Receptor, EphA2