Platelet Protease-Activated Receptor (PAR)

Platelet protease-activated receptors (PARs) are a family of G-protein-coupled receptors (GPCRs) that play a central role in platelet activation, aggregation, and the regulation of hemostasis and thrombosis. The main subtypes in human platelets are PAR1 and PAR4, both activated by thrombin. Activation involves proteolytic cleavage by serine proteases, exposure of a tethered ligand, and intramolecular binding to initiate intracellular signaling. PAR1 is a high-affinity thrombin receptor mediating rapid platelet responses, while PAR4 has lower affinity and mediates slower, sustained responses. PARs are therapeutic targets for antithrombotic therapy.

Other names

Protease-Activated ReceptorPAR1PAR4

Inhibition of platelet activation by blocking protease-mediated receptor cleavage and activation, or by blocking the tethered ligand binding site.