Platelet glycoprotein Ib alpha chain also known as glycoprotein Ib (platelet), alpha polypeptide or CD42b (Cluster of Differentiation 42b), is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
that in humans is encoded by the ''GP1BA''
gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
.
Function
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
Von Willebrand factor (VWF) () is a blood glycoprotein involved in hemostasis, specifically, platelet adhesion. It is deficient and/or defective in von Willebrand disease and is involved in many other diseases, including thrombotic thrombocytopen ...
(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 The GPIb-IX-V complex is a profuse membrane receptor complex originating in megakaryocytes and exclusively functional on the surface of platelets. It primarily functions to mediate the first critical step in platelet adhesion, by facilitating bind ...
. 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 syndrome
Bernard–Soulier syndrome (BSS) is a rare autosomal recessive bleeding disorder that is caused by a deficiency of the ''glycoprotein Ib-IX-V complex'' (GPIb-IX-V), the receptor for von Willebrand factor. The incidence of BSS is estimated to be l ...
s and platelet-type
von Willebrand disease
Von Willebrand disease (VWD) is the most common hereditary 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 von Willebrand factor ( ...
.
Interactions
GP1BA has been shown to
interact
Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization using innovative strategies to advocate for the legal and human rights of children with intersex traits. The organizati ...
with
YWHAZ
14-3-3 protein zeta/delta (14-3-3ζ) is a protein that in humans is encoded by the ''YWHAZ'' gene on chromosome 8. The protein encoded by this gene is a member of the 14-3-3 protein family and a central hub protein for many signal transduction pat ...
and
FLNB
Filamin B, beta (FLNB), also known as Filamin B, beta (truncated actin binding protein 278 homolog), is a cytoplasmic protein which in humans is encoded by the ''FLNB'' gene.
FLNB regulates intracellular communication and signalling by cross-linki ...
.
See also
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Cluster of differentiation
The cluster of differentiation (also known as cluster of designation or classification determinant and often abbreviated as CD) is a protocol used for the identification and investigation of cell surface molecules providing targets for immunophen ...
References
Further reading
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External links
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Clusters of differentiation
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