Prostacyclin Receptor (PTGIR)

Prostacyclin receptor is a member of the G-protein coupled receptor family. Prostacyclin, the major product of cyclooxygenase in macrovascular endothelium, elicits a potent vasodilation and inhibition of platelet aggregation through binding to this receptor.

When binding a prostacyclin-molecule, the receptor changes conformation and activates G_s, with its activation of cAMP and increase in protein kinase A (PKA) activity.In vasodilation, the PKA activity causes phosphorylation of MLCK, decreasing its activity, resulting in dephosphorylation of MLC of myosin. The smooth muscle relaxation leads to vasodilation.