GP1BA

Platelet glycoprotein Ib alpha chain, also known as glycoprotein Ib (platelet), alpha polypeptide or CD42b (Cluster of Differentiation 42b), is a protein that in humans is encoded by the GP1BA gene.

GP1BA
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 1GWB, 1M0Z, 1M10, 1OOK, 1P8V, 1P9A, 1QYY, 1SQ0, 1U0N, 2BP3, 3P72, 3PMH, 4C2A, 4C2B, 4CH2, 4CH8, 4MGX, 4YR6
Identifiers
Aliases	GP1BA, BDPLT1, BDPLT3, BSS, CD42B, CD42b-alpha, DBPLT3, GP1B, GPIbA, VWDP, GPIbalpha, glycoprotein Ib platelet alpha subunit, glycoprotein Ib platelet subunit alpha
External IDs	OMIM: 606672; MGI: 1333744; HomoloGene: 143; GeneCards: GP1BA; OMA:GP1BA - orthologs
Gene location (Human) Chr. Chromosome 17 (human)[1] Band 17p13.2 Start 4,932,277 bp[1] End 4,935,023 bp[1]
Gene location (Mouse) Chr. Chromosome 11 (mouse)[2] Band 11 B3|11 43.2 cM Start 70,529,948 bp[2] End 70,532,862 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in monocyte lymph node buccal mucosa cell secondary oocyte trabecular bone granulocyte blood bone marrow cells mucosa of ileum tibialis anterior muscle Top expressed in blood tibiofemoral joint granulocyte embryo muscle of thigh neural layer of retina yolk sac morula spleen lumbar subsegment of spinal cord More reference expression data BioGPS More reference expression data
Gene ontology Molecular function protein kinase inhibitor activity thrombin-activated receptor activity protein binding Cellular component cytoplasm integral component of membrane membrane plasma membrane integral component of plasma membrane cell surface anchored component of external side of plasma membrane extracellular exosome extracellular space extracellular matrix Biological process blood coagulation, intrinsic pathway hemostasis fibrinolysis negative regulation of protein kinase activity cytokine-mediated signaling pathway blood coagulation platelet activation cell surface receptor signaling pathway cell adhesion cell morphogenesis regulation of blood coagulation negative regulation of receptor signaling pathway via JAK-STAT thrombin-activated receptor signaling pathway platelet aggregation regulation of megakaryocyte differentiation Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 2811 14723 Ensembl ENSG00000185245 ENSMUSG00000050675 UniProt P07359 O35930 RefSeq (mRNA) NM_000173 NM_010326 RefSeq (protein) NP_000164 NP_034456 Location (UCSC) Chr 17: 4.93 – 4.94 Mb Chr 11: 70.53 – 70.53 Mb PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

Function

Glycoprotein Ib (GP Ib) is a platelet surface membrane glycoprotein receptor composed of a heterodimer, an alpha chain and a beta chain, that are linked by disulfide bonds.^[5] The Gp Ib functions as a receptor for von Willebrand factor (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. Binding of the GP Ib-IX-V complex to VWF facilitates initial platelet adhesion to vascular subendothelium after vascular injury,^[6] and also initiates signaling events within the platelet that lead to enhanced platelet activation, thrombosis, and hemostasis.^[7] 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 syndromes and platelet-type von Willebrand disease.^[8]

Interactions

GP1BA has been shown to interact with YWHAZ^[9][10][11] and FLNB.^[12]

Inhibitors

CCP-224, a short PEG-conjugated form of the cyclic peptide OS-1, binds to human GPIb alpha with high affinity and can prevents neutrophil-platelet aggregation in Sickle Cell Disease.^[13] In vivo, platelet-mediated thrombus formation can be greatly reduced in arterioles of mice, injured by laser, following an infusion of the OS-1 peptide.^[14] The OS-1 peptide prevents binding of GPIb alpha to the VWF A1 domain.^[15] The co-crystal structure of GPIb alpha and OS-1 has been reported.^[16]

See also

• Cluster of differentiation