Cell-induced potentiation of the plasminogen activation system is abolished by a monoclonal antibody that recognizes the NH2-terminal domain of the urokinase receptor

• Published in: FEBS letters 1991-08, Vol.288 (1-2), p.233-236
• Main Authors: Rønne, Ebbe, Behrendt, Niels, Ellis, Vincent, Ploug, Michael, Danø, Keld, Høyer-Hansen, Gunilla
• Format: Article
• Language: English
• Subjects: 2,4,6-trinitrophenol; 3-[3-cholamidopropyl)dimethylammonio]-1-propanesulfonate; Antibodies, Monoclonal; ATF; Biological and medical sciences; bovine serum albumin; BSA; Cell Line; Cell receptors; Cell structures and functions; CHAPS; Chymotrypsin - metabolism; DFP; diisopropyl fluorophosphate; disuccinimidyl suberate; DSS; Epitopes - immunology; Fibrinolysin - analysis; Fundamental and applied biological sciences. Psychology; Humans; Kinetics; Miscellaneous; Molecular and cellular biology; Monoclonal antibody; NH2-terminal fragment (1–135) of u-PA; PBS; phorbol 12-myristate 13-acetate; phosphate-buffered saline; Plasminogen - metabolism; Plasminogen activation; Plasminogen Activators - metabolism; PMA; Precipitin Tests; pro-u-PA; Receptors, Cell Surface - immunology; Receptors, Cell Surface - metabolism; Receptors, Urokinase Plasminogen Activator; SDS-PAGE; sodium dodecyl sulfate polyacrylamide gel electrophoresis; Structure-Activity Relationship; TNP; u-PA; u-PA receptor; u-PAR; U937 cell; Urokinase receptor; urokinase-type plasminogen activator; zymogenic form of u-PA
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(91)81042-7

We have raised four monoclonal antibodies recognizing different epitopes within the human cell-surface receptor for urokinase-type plasminogen activator (u-PA). One of these antibodies completely abolishes the potentiation of plasmin generation observed upon incubation of the zymogens pro-u-PA and plasminogen with U937 cells. This antibody, which is also the only one to completely inhibit the binding of DFP-inactivated [125I]-u-PA to U937 cells, is directed against the u-PA binding NH2-terminal domain of u-PAR, a well-defined fragment formed by limited chymotrypsin digestion of purified u-PAR, demonstrating the functional independence of the u-PA binding domain as well as the critical role of u-PAR in the assembly of the cell-surface plasminogen activation system.