Platelet glycoprotein Ib alpha chain (GP1BA)
The protein contains 652 amino acids for an estimated molecular weight of 71540 Da.
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. (updated: Sept. 12, 2018)
Protein identification was indicated in the following studies:
- Hegedűs and co-workers. (2015) Inconsistencies in the red blood cell membrane proteome analysis: generation of a database for research and diagnostic applications. Database (Oxford) 1-8.
- D'Alessandro and co-workers. (2017) Red blood cell proteomics update: is there more to discover? Blood Transfus. 15(2), 182-187.
Methods
The following articles were analysed to gather the proteome content of erythrocytes.
The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.
| Publication | Identification 1 | Uniprot mapping 2 | Not mapped / Obsolete | TrEMBL | Swiss-Prot |
|---|---|---|---|---|---|
| Goodman (2013) | 2289 (gene list) | 2278 | 53 | 20599 | 2269 |
| Lange (2014) | 1234 | 1234 | 7 | 28 | 1224 |
| Hegedus (2015) | 2638 | 2622 | 0 | 235 | 2387 |
| Wilson (2016) | 1658 | 1528 | 170 | 291 | 1068 |
| d'Alessandro (2017) | 1826 | 1817 | 2 | 0 | 1815 |
| Bryk (2017) | 2090 | 2060 | 10 | 108 | 1942 |
| Chu (2018) | 1853 | 1804 | 55 | 362 | 1387 |
1 as available in the article and/or in supplementary material
2 uniprot mapping returns all protein isoforms as one entry
The compilation of older studies can be retrieved from the Red Blood Cell Collection database.
The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.
This protein is annotated as membranous in Gene Ontology, is predicted to be membranous by TOPCONS.
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| Variant | Description |
|---|---|
| dbSNP:rs6068 | |
| BSS | |
| BSS | |
| dbSNP:rs13306411 | |
| BSS | |
| Siba(+) | |
| BSS and BSSA2 | |
| BSS | |
| VWDP | |
| VWDP | |
| dbSNP:rs382524 | |
| VWDP |
No binding partner found
Biological Process
Blood coagulation
Blood coagulation, intrinsic pathway
Cell adhesion
Cell morphogenesis
Cell surface receptor signaling pathway
Fibrinolysis
Platelet activation
Platelet aggregation
Regulation of blood coagulation
Regulation of megakaryocyte differentiation
The reference OMIM entry for this protein is 153670
Bernard-soulier syndrome, type a2, autosomal dominant; bssa2
A number sign (#) is used with this entry because of evidence that an autosomal dominant form of Bernard-Soulier syndrome can be caused by heterozygous mutations in the gene encoding platelet glycoprotein Ib-alpha (GP1BA; 606672) on chromosome 17p. Homozygous or compound heterozygous mutations in the GP1BA gene cause classic autosomal recessive Bernard-Soulier syndrome (BSSA1; 231200).
CLINICAL FEATURES
Miller et al. (1992) reported a 2-generation family in which 5 individuals had a moderate bleeding tendency, thrombocytopenia, and an increased mean platelet volume. The pedigree pattern was consistent with autosomal dominant inheritance. Savoia et al. (2001) reported 6 Italian families with variable manifestations of a mild bleeding diathesis, incidental discovery of thrombocytopenia, or platelet macrocytosis. Some individuals had no symptoms. Mild bleeding tendencies were manifest as epistaxis, gingival bleeding, menorrhagia, easy bruising, or prolonged bleeding after dental surgery. Members of 3 families had bone marrow examination that showed normal numbers of megakaryocytes.MAPPING
By linkage analysis of 2 large Italian families with autosomal dominant macrothrombocytopenia, Savoia et al. (2001) found linkage to a region on chromosome 17p, in an interval containing the GP1BA gene (606672).MOLECULAR GENETICS
In a Caucasian family in which 5 members over 2 generations were affected with a mild form of Bernard-Soulier syndrome in an unusual autosomal dominant pattern of inheritance, Miller et al. (1992) identified a heterozygous mutation in the GP1BA gene (L57F; 606672.0004). In affected individuals of 6 Italian families with autosomal dominant inheritance of large platelets, thrombocytopenia, and mild bleeding tendencies, Savoia et al. (2001) identified a heterozygous mutation in the GP1BA gene (A156V; 606672.0006). The patients were originally thought to have Mediterranean macrothrombocytopenia (see 210250). However, the results of Savoia et al. (2001) indicated that a subset of patients diagnosed with so-called Mediterranean macrothrombocytopenia may actually have a heterozygous type of Bernard-Soulier syndrome. ... More on the omim web site
June 30, 2020: Protein entry updated
Automatic update: OMIM entry 153670 was added.
Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).