Cutting Edge: Evidence for a Signaling Partnership Between Urokinase Receptors (CD87) and L-Selectin (CD62L) in Human Polymorphonuclear Neutrophils
| Autor: | Pauline M. Pan, Howard R. Petty, R. Alexander Blackwood, Robert G. Sitrin, Jibiao Huang |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Glycosylation
Neutrophils Immunology Integrin Receptors Cell Surface Ligands Neutrophil Activation Receptors Urokinase Plasminogen Activator Cell Adhesion Humans Immunology and Allergy L-Selectin skin and connective tissue diseases Receptor Cell adhesion neoplasms biology Chemistry Chemotaxis Urokinase-Type Plasminogen Activator Molecular biology biological factors Protein Structure Tertiary Urokinase receptor enzymes and coenzymes (carbohydrates) Spectrometry Fluorescence Energy Transfer biology.protein Carbohydrate Metabolism L-selectin biological phenomena cell phenomena and immunity Signal transduction Protein Binding Signal Transduction Binding domain |
| Zdroj: | The Journal of Immunology. 166:4822-4825 |
| ISSN: | 1550-6606 0022-1767 |
| Popis: | Leukocyte urokinase plasminogen activator receptors (uPARs) cluster at adhesion interfaces and at migratory fronts where they participate in adhesion, chemotaxis, and proteolysis. uPAR aggregation triggers activation signaling even though this glycolipid-anchored protein must associate with membrane-spanning proteins to access the cell interior. This study demonstrates a novel partnership between uPAR and L-selectin in human polymorphonuclear neutrophils. Fluorescence resonance energy transfer demonstrated a direct physical association between uPAR and L-selectin. To examine the role of L-selectin in uPAR-mediated signaling, uPAR was cross-linked and intracellular Ca2+ concentrations were measured by spectrofluorometry. A mAb reactive against the carbohydrate binding domain (CBD) of L-selectin substantially inhibited uPAR-mediated Ca2+ mobilization, whereas mAbs against the β2 integrin complement receptor 3 (CR3), another uPAR-binding adhesion protein, had no effect. Similarly, fucoidan, a sulfated polysaccharide that binds to L-selectin CBD, inhibited the Ca2+ signal. We conclude that uPAR associates with the CBD region of L-selectin to form a functional signaling complex. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|