Ligand binding regions in the receptor for urokinase-type plasminogen activator

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

  • O D Liang - , Technische Universität Berlin (Autor:in)
  • T Chavakis - , Justus-Liebig-Universität Gießen (Autor:in)
  • S M Kanse - (Autor:in)
  • K T Preissner - (Autor:in)

Abstract

The interaction between urokinase plasminogen activator (uPA) and its cellular receptor (uPAR) is a key event in cell surface-associated plasminogen activation, relevant for cell migration and invasion. In order to define receptor recognition sites for uPA, we have expressed uPAR fragments as fusion products with the minor coat protein on the surface of M13 bacteriophages. Sequence analysis of cDNA fragments encoding uPA-binding peptides indicated the existence of a composite uPA-binding structure including all three uPAR domains. This finding was confirmed by experiments using an overlapping 15-mer peptide array covering the entire uPAR molecule. Four regions within the uPAR sequence were found to directly bind to uPA: two distinct regions containing amino acids 13--20 and amino acids 74--84 of the uPAR domain I, and regions in the putative loop 3 of the domains II and III. All the uPA-binding fragments from the three domains were shown to have an agonistic effect on uPA binding to immobilized uPAR. Furthermore, uPAR-(154--176) increased uPAR-transfected BAF3-cell adhesion on vitronectin in the presence of uPA, whereas uPAR-(247--276) stimulated the cell adhesion both in the absence or presence of uPA. The latter fragment was also able to augment the binding of vitronectin to uPAR in a purified system, thereby mimicking the effect of uPA on this interaction. These results indicate that uPA binding can take place to particular part(s) on several uPAR molecules and that direct uPAR-uPAR contacts may contribute to receptor activation and ligand binding.

Details

OriginalspracheEnglisch
Seiten (von - bis)28946-28953
Seitenumfang8
FachzeitschriftThe Journal of biological chemistry
Jahrgang276
Ausgabenummer31
PublikationsstatusVeröffentlicht - 3 Aug. 2001
Peer-Review-StatusJa
Extern publiziertJa

Externe IDs

Scopus 0035800857

Schlagworte

Schlagwörter

  • Amino Acid Sequence, Binding Sites, Binding, Competitive, Chromatography, Affinity, DNA, Complementary, Humans, Kinetics, Ligands, Models, Molecular, Molecular Sequence Data, Peptide Fragments/chemistry, Protein Conformation, Receptors, Cell Surface/chemistry, Receptors, Urokinase Plasminogen Activator, Recombinant Fusion Proteins/chemistry, Recombinant Proteins/chemistry, Sequence Alignment, Urokinase-Type Plasminogen Activator/chemistry, Vitronectin/blood

Bibliotheksschlagworte