GP1BB

Protein identityUniProt · HPA

UniProt accession

P13224

Gene

GP1BB

Ensembl

ENSG00000203618

Chromosome

22

Canonical length

206 aa

Protein class

CD markers, Disease related genes, Human disease related genes, Predicted membrane proteins

OverviewNCBI Gene

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]

Canonical amino-acid sequenceUniProt

206 residues, UniProt reviewed canonical sequence.

>P13224|GP1BB
     1  MGSGPRGALS LLLLLLAPPS RPAAGCPAPC SCAGTLVDCG RRGLTWASLP TAFPVDTTEL
    61  VLTGNNLTAL PPGLLDALPA LRTAHLGANP WRCDCRLVPL RAWLAGRPER APYRDLRCVA
   121  PPALRGRLLP YLAEDELRAA CAPGPLCWGA LAAQLALLGL GLLHALLLVL LLCRLRRLRA
   181  RARARAAARL SLTDPLVAER AGTDES

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against GP1BB can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability

Cell surface

Secreted

No

Transmembrane segments

1

Mean surface accessibility (rSASA)

0.41

Highest tissue expression

93 nTPM

Expression across tissuesHPA

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about GP1BB.

Disease | AllUniProt

Conditions GP1BB is implicated in, by any mechanism.

• Bernard-Soulier syndrome (BSS) MIM:231200

Disease | GeneticClinVar

46 pathogenic / likely-pathogenic of 158 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

• Bernard Soulier syndrome
• Macrothrombocytopenia
• Thrombocytopenia
• Bernard-Soulier syndrome, type B
• MACROTHROMBOCYTOPENIA, FAMILIAL, BERNARD-SOULIER TYPE

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)

1.33

gnomAD pLI

0.51

gnomAD missense Z

0.46

DepMap mean gene effect

-0.2

DepMap dependency class

selective

OntologyGO

Biological processes

• blood coagulation, intrinsic pathway
• cell adhesion
• cell surface receptor signaling pathway
• megakaryocyte development
• platelet activation
• positive regulation of platelet activation
• release of sequestered calcium ion into cytosol

Molecular functions

• identical protein binding
• transmembrane signaling receptor activity

Cellular components

• glycoprotein Ib-IX-V complex
• plasma membrane

Protein domainsUniProt · Pfam · InterPro

• Leucine-rich repeat N-terminal domain
• Cysteine-rich flanking region, C-terminal
• Leucine-rich repeat domain superfamily
• Platelet Glycoprotein Ib-IX-V Complex

KeywordsUniProt

• Bernard Soulier syndrome
• Blood coagulation
• Cell adhesion
• Disulfide bond
• Glycoprotein
• Hemostasis
• Leucine-rich repeat
• Membrane
• Phosphoprotein
• Signal
• Transmembrane
• Transmembrane helix

InteractionsUniProt · HPA

Protein binding partners of GP1BB in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

• TRAF4