THE THROMBIN RECEPTOR

1. The thrombin receptor has now been cloned and found to be a member of the G-protein-coupled seven-transmembrane domain receptor family. 2 . The receptor has been detected directly in platelets, endothelial ce lls and smooth muscle cells and studies using receptor-derived peptide s have demonstrated that this receptor may be the one responsible for many of the actions of thrombin in platelets, endothelial cells, smoot h muscle cells, fibroblasts, mesangial cells and neural cells. 3. The receptor appears to be activated by the novel mechanism of cleavage by thrombin to yield a new N-terminus which then interacts with the rece ptor as a tethered ligand to initiate cell activation.