Glycoprotein Ib (GPIb), also known as CD42,
is a component of the
GPIb-V-IX complex on
platelets
Platelets or thrombocytes () are a part of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping to form a blood clot. Platelets have no cell nucleus; they are fragments of cyto ...
. The GPIb-V-IX complex binds
von Willebrand factor, allowing
platelet adhesion
Platelets or thrombocytes () are a part of blood whose function (along with the coagulation#Coagulation factors, coagulation factors) is to react to bleeding from blood vessel injury by clumping to form a thrombus, blood clot. Platelets have no ...
and
platelet plug
The platelet plug, also known as the hemostatic plug or platelet thrombus, is an aggregation of platelets formed during early stages of hemostasis in response to one or more injuries to blood vessel walls. After platelets are recruited and begin ...
formation at sites of vascular injury. Glycoprotein Ibα (GPIbα) is the major ligand-binding subunit of the GPIb-V-IX complex. GPIbα is heavily glycosylated.
It is deficient in the
Bernard–Soulier syndrome. A
gain-of-function mutation
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mitosi ...
causes platelet-type
von Willebrand disease
Von Willebrand disease (VWD) is the most common heredity, hereditary coagulopathy, blood-clotting disorder in humans. An acquired form can sometimes result from other medical conditions. It arises from a deficiency in the quality or quantity of ...
.
Autoantibodies against Ib/IX can be produced in
immune thrombocytopenic purpura.
Components include
GP1BA and
GP1BB.
It complexes with
Glycoprotein IX.
References
External links
*
Glycoproteins
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