Platelet glycoprotein Ib alpha receptor (GPIbα)

Platelet glycoprotein Ib alpha receptor (GPIbα) is a transmembrane glycoprotein that serves as the primary ligand-binding subunit of the GPIb-IX complex on platelet surfaces[1][3][5]. It plays a vital role in hemostasis by mediating the tethering of platelets to sites of vascular injury through binding to von Willebrand factor (VWF) under high shear stress[2][5][6]. This initiates platelet adhesion, signaling to activate integrins (such as αIIbβ3), and promotes thrombus formation. GPIbα contains multiple structural domains, including a heavily glycosylated extracellular domain with leucine-rich repeats, a mechanosensory domain, and short cytoplasmic regions that associate with signaling proteins like filamin A and 14-3-3ζ[1][7]. Mutations or deficiencies in GPIbα result in the rare bleeding disorder Bernard-Soulier syndrome, and its function is implicated in arterial thrombosis, thrombocytopenia, von Willebrand disease, cancer metastasis, and inflammation[8]. GPIbα is an emerging target for antithrombotic therapies, but inhibitors may cause significant bleeding due to its essential role in primary hemostasis[5][8].

Other names

Glycoprotein Ib alphaGPIb-alphaGPIbαPlatelet glycoprotein Ib-IX receptor (as part of the larger GPIb-IX complex)GP1BA (gene symbol)CD42b

Blockade of the GPIbα-von Willebrand factor interaction, preventing platelet adhesion and aggregation, thus impeding thrombus formation Inhibition of GPIbα signaling pathways leading to decreased platelet activation