What platelet membrane receptor binds fibrinogen and supports platelet aggregation?

The platelet membrane receptor responsible for binding fibrinogen and facilitating platelet aggregation is GP IIb/IIIa. This receptor is a critical integrin that plays a central role in the process of hemostasis. When platelets are activated, GP IIb/IIIa undergoes a conformational change that allows it to bind fibrinogen, which is a soluble plasma glycoprotein. This binding is crucial because it links platelets together, leading to the formation of a platelet plug during the clotting process.

The importance of GP IIb/IIIa in platelet aggregation is underscored by the fact that drugs targeting this receptor, such as glycoprotein IIb/IIIa inhibitors, are used therapeutically to prevent thrombotic events in patients with cardiovascular disease. This highlights the receptor's significant role in promoting platelet interaction during clot formation.

Other receptors mentioned, such as GP Ib/IX/V, are primarily involved in the initial adhesion of platelets to the damaged endothelial surface, while GP Ia/IIa is primarily involved in binding collagen. The P2Y1 receptor serves as a purinergic receptor that is activated by ADP, playing a role in platelet activation and aggregation as well, but it is GP II