title: Characterization of B61, the ligand for the Eck receptor protein-tyrosine kinase.
abstract: B61 was originally described as a novel secreted tumor necrosis factor-alpha-inducible gene product in endothelial cells (Holzman, L. B., Marks, R. M., and Dixit, V. M. (1990) Mol. Cell. Biol. 10, 5830-5838). It was recently discovered that soluble recombinant B61 could serve as a ligand for the Eck receptor protein-tyrosine kinase, a member of the Eph/Eck subfamily of receptor protein-tyrosine kinases (Bartley, T.D., Hunt, R. W., Welcher, A. A., Boyle, W. J., Parker, V. P., Lindberg, R. A., Lu, H. S., Colombero, A. M., Elliott, R. L., Guthrie, R. A., Holst, P. L., Skrine, J. D., Toso, R. J., Zhang, M., Fernandez, E., Trail, G., Yarnum, B., Yarden, Y., Hunter, T., and Fox, G. M. (1994) Nature 368, 558-560). We now show that B61 can also exist as a cell surface glycosylphosphatidyl-inositol-linked protein that is capable of activating the Eck receptor protein-tyrosine kinase, the first such report of a receptor protein-tyrosine kinase ligand that is glycosylphosphatidylinositol-linked. In addition, the expression patterns of B61 and Eck during mouse ontogeny were determined by in situ hybridization. Both were found to be highly expressed in the developing lung and gut, while Eck was preferentially expressed in the thymus. Finally, the gene for B61 was localized to a specific position on mouse chromosome 3 by interspecific back-cross analysis.
authors.affiliation: Department of Pathology, University of Michigan Medical School, Ann Arbor 48109.
authors.forename: H
authors.initials: H
authors.lastname: Shao
authors.forename: A
authors.initials: A
authors.lastname: Pandey
authors.forename: K S
authors.initials: KS
authors.lastname: O'Shea
authors.forename: M
authors.initials: M
authors.lastname: Seldin
authors.forename: V M
authors.initials: VM
authors.lastname: Dixit
mesh_terms: D000818:Animals; D002874:Chromosome Mapping; D003433:Crosses, Genetic; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism; D005314:Embryonic and Fetal Development; D036382:Ephrin-A1; D005260:Female; D015870:Gene Expression; D017261:Glycosylphosphatidylinositols / Q000032:analysis / Q000378:metabolism; D017403:In Situ Hybridization; D008024:Ligands; D008297:Male; D008565:Membrane Proteins / Q000032:analysis / Q000096:biosynthesis*; D051379:Mice; D008809:Mice, Inbred C3H; D009115:Muridae; D009928:Organ Specificity; D014176:Protein Biosynthesis; D011505:Protein-Tyrosine Kinases / Q000096:biosynthesis*; D011506:Proteins / Q000032:analysis / Q000235:genetics*; D020794:Receptor Protein-Tyrosine Kinases / Q000032:analysis / Q000096:biosynthesis; D036104:Receptor, EphA2; D013950:Thymus Gland / Q000166:cytology / Q000378:metabolism*
chemical_list: D036382:Ephrin-A1; D017261:Glycosylphosphatidylinositols; D008024:Ligands; D008565:Membrane Proteins; D011506:Proteins; D011505:Protein-Tyrosine Kinases; D020794:Receptor Protein-Tyrosine Kinases; D036104:Receptor, EphA2