title: Removal of domain D2 or D3 of the human urokinase receptor does not affect ligand affinity.
abstract: The main ligand-binding determinant of the human urokinase receptor (uPAR) is located in the amino terminal domain D1, but when isolated this domain presents a 1500 fold lower affinity than the intact three-domain uPAR (D1D2D3). uPAR mutants missing either domain 2 (D1HD3) or domain 3 (D1D2) were expressed in murine LB6 cells and showed to be properly GPI-anchored to the cell surface. Binding assays with [125I]ATF demonstrated that these mutants possessed a normal (D1D2) or slightly reduced (D1HD3) affinity, indicating that a high ligand-affinity may be achieved by a combination of D1 with domain D2 or D3.
authors.affiliation: Department of Biology and Biotechnology (DIBIT), San Raffaele Scientific Institute, Milan, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Riittinen
authors.forename: P
authors.initials: P
authors.lastname: Limongi
authors.forename: M P
authors.initials: MP
authors.lastname: Crippa
authors.forename: M
authors.initials: M
authors.lastname: Conese
authors.forename: L
authors.initials: L
authors.lastname: Hernandez-Marrero
authors.forename: F
authors.initials: F
authors.lastname: Fazioli
authors.forename: F
authors.initials: F
authors.lastname: Blasi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002999:Clone Cells; D005455:Fluorescent Antibody Technique; D017261:Glycosylphosphatidylinositols / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D007739:L Cells; D008024:Ligands; D051379:Mice; D008969:Molecular Sequence Data; D016296:Mutagenesis; D016254:Mutagenesis, Insertional; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D010727:Phosphoric Diester Hydrolases / Q000096:biosynthesis / Q000378:metabolism / Q000494:pharmacology; D011956:Receptors, Cell Surface / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism*; D055293:Receptors, Urokinase Plasminogen Activator; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism; D014162:Transfection; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism
chemical_list: D017261:Glycosylphosphatidylinositols; D008024:Ligands; C524898:PLAUR protein, human; C524899:Plaur protein, mouse; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator; D011994:Recombinant Proteins; D010727:Phosphoric Diester Hydrolases; D014568:Urokinase-Type Plasminogen Activator; D043265:Phosphatidylinositol Diacylglycerol-Lyase