GP1BB

Platelet glycoprotein Ib (GPIb) is a heterodimeric transmembrane protein consisting of a disulfide-linked 140 kD alpha chain and 22 kD beta chain. It is part of the GPIb-V-IX system that constitutes the receptor for von Willebrand factor (VWF), and mediates platelet adhesion in the arterial circulation. GPIb alpha chain provides the VWF binding site, and GPIb beta contributes to surface expression of the receptor and participates in transmembrane signaling through phosphorylation of its intracellular domain. Mutations in the GPIb beta subunit have been associated with Bernard-Soulier syndrome, velocardiofacial syndrome and giant platelet disorder. The 206 amino acid precursor of GPIb beta is synthesized from a 1.0 kb mRNA expressed in plateletes and megakaryocytes. A 411 amino acid protein arising from a longer, unspliced transcript in endothelial cells has been described; however, the authenticity of this product has been questioned. Yet another less abundant GPIb beta mRNA species of 3.5 kb, expressed in nonhematopoietic tissues such as endothelium, brain and heart, was shown to result from inefficient usage of a non-consensus polyA signal in the neighboring upstream gene (SEPT5, septin 5). In the absence of polyadenylation from its own imperfect site, the SEPT5 gene produces read-through transcripts that use the consensus polyA signal of this gene. [provided by RefSeq, Dec 2010]

Description

Glycoprotein Ib platelet subunit beta

Tissue specificity

Tissue enhanced (brain, heart muscle)

Predicted location

Membrane

Protein family

CD markers
Disease related genes
Human disease related genes
Mapped to neXtProt
Mapped to UniProt SWISS-PROT
Predicted membrane proteins
Protein evidence (Ezkurdia et al 2014)
Protein evidence (Kim et al 2014)

Chromosome

22 (19723539 - 19724771)

Ensembl ID

ENSG00000203618  (ver. 103.38)

Orthologs

Mouse Gp1bb: ENSMUSG00000050761

UniProt

P13224

neXtProt

NX_P13224

Human splice variants
Mouse splice variants

Protein structure