GP1BA

Platelet glycoprotein Ib alpha chain, also known as glycoprotein Ib (platelet), alpha polypeptide or CD42b (Cluster of Differentiation 42b), is a protein that in humans is encoded by the GP1BA gene.

Function

Glycoprotein Ib (GP Ib) is a platelet surface membrane glycoprotein receptor composed of a heterodimer, an alpha chain and a beta chain, that are linked by disulfide bonds. The Gp Ib functions as a receptor for von Willebrand factor (VWF). The complete receptor complex includes noncovalent association of the alpha and beta subunits with platelet glycoprotein IX and platelet glycoprotein V to form the glycoprotein Ib-IX-V complex. Binding of the GP Ib-IX-V complex to VWF facilitates initial platelet adhesion to vascular subendothelium after vascular injury, and also initiates signaling events within the platelet that lead to enhanced platelet activation, thrombosis, and hemostasis. This gene encodes the alpha subunit. Several polymorphisms and mutations have been described in this gene, some of which are the cause of Bernard–Soulier syndromes and platelet-type von Willebrand disease.

Interactions

GP1BA has been shown to interact with YWHAZ and FLNB.

Inhibitors

CCP-224, a short PEG-conjugated form of the cyclic peptide OS-1, binds to human GPIb alpha with high affinity and can prevents neutrophil-platelet aggregation in Sickle Cell Disease. In vivo, platelet-mediated thrombus formation can be greatly reduced in arterioles of mice, injured by laser, following an infusion of the OS-1 peptide. The OS-1 peptide prevents binding of GPIb alpha to the VWF A1 domain. The co-crystal structure of GPIb alpha and OS-1 has been reported.

See also

• Cluster of differentiation

External links

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This article incorporates text from the United States National Library of Medicine, which is in the public domain.