GP1BA

Glycoprotein Ib (GP Ib) is a platelet surface membrane glycoprotein 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. The 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. [provided by RefSeq]

Glycoprotein Ib Platelet Alpha Subunit

GP-Ib, a surface membrane protein of platelets, participates in the formation of platelet plugs by binding to the A1 domain of vWF, which is already bound to the subendothelium.

Blood coagulation Source: MGI
Cell adhesion Source: MGI
Cell morphogenesis Source: Ensembl
Cell surface receptor signaling pathway Source: ProtInc
Fibrinolysis Source: UniProtKB
Platelet activation Source: UniProtKB
Platelet aggregation Source: GO_Central
Regulation of blood coagulation Source: UniProtKB

Membrane

Non-arteritic anterior ischemic optic neuropathy (NAION):
An ocular disease due to ischemic injury to the optic nerve. It usually affects the optic disk and leads to visual loss and optic disk swelling of a pallid nature. Visual loss is usually sudden, or over a few days at most and is usually permanent, with some recovery possibly occurring within the first weeks or months. Patients with small disks having smaller or non-existent cups have an anatomical predisposition for non-arteritic anterior ischemic optic neuropathy. As an ischemic episode evolves, the swelling compromises circulation, with a spiral of ischemia resulting in further neuronal damage.
Bernard-Soulier syndrome (BSS):
A coagulation disorder characterized by a prolonged bleeding time, unusually large platelets, thrombocytopenia, and impaired prothrombin consumption.
Bernard-Soulier syndrome A2, autosomal dominant (BSSA2):
A coagulation disorder characterized by mild to moderate bleeding tendency, thrombocytopenia, and an increased mean platelet volume. Some individuals have no symptoms. Mild bleeding tendencies manifest as epistaxis, gingival bleeding, menorrhagia, easy bruising, or prolonged bleeding after dental surgery.
Pseudo-von Willebrand disease (VWDP):
A bleeding disorder characterized by abnormally enhanced binding of von Willebrand factor by the platelet glycoprotein Ib (GP Ib) receptor complex. Hemostatic function is impaired due to the removal of VWF multimers from the circulation.

Extracellular: 17-531
Helical: 532-552
Cytoplasmic: 553-652

Glycocalicin is the product of a proteolytic cleavage/shedding, catalyzed by ADAM17, which releases most of the extracellular domain. Binding sites for vWF and thrombin are in this part of the protein.