Biomaterial Database

Bernard-Soulier syndrome. 1989

M C Berndt, and D J Fournier, and P A Castaldi

Bernard-Soulier syndrome (BSS) is a rare autosomal bleeding disorder characterized clinically by prolonged skin bleeding time, normal clot retraction and thrombocytopenia with large and morphologically abnormal platelets, and biochemically by the absence of platelet membrane glycoproteins (GP) Ib, V and IX. GP Ib and GP IX exist in the platelet membrane as a heterodimer complex which acts as the major receptor mediating platelet adhesion to blood vessel subendothelium. Studies with BSS platelets have proved particularly rewarding in the investigation of the GP Ib-IX complex as a multifunctional receptor protein. The transmembrane complex contains binding domains for von Willebrand factor, thrombin, fibrin and quinine/quinidine drug-dependent antibodies as well as an attachment site on the cytoplasmic side of the membrane for a platelet cytoskeleton. In addition, the internal segment of the beta-chain of GP Ib contains a cyclic AMP-dependent protein kinase-associated phosphorylation site which appears to regulate platelet reactivity. Limited proteolytic cleavage of the complex, in particular the GP Ib alpha-chain, has allowed immunological and functional characterization of three distinct domains; a 45 kDa segment at the N-terminal end of the alpha-chain of GP Ib, which contains binding sites for von Willebrand factor and thrombin, a 90 kDa highly glycosylated region of GP Ib alpha and a membrane-associated region consisting of the remnant of GP Ib alpha disulphide-linked to GP Ib beta and non-covalently-complexed with GP IX. This membrane-associated region contains the antigenic epitope(s) for quinine/quinidine drug-dependent antibodies. It is highly probable that the future study of platelets from patients with the Bernard-Soulier syndrome will further clarify the role of the GP Ib-IX complex in platelet physiology.

UI	MeSH Term	Description	Entries
D010973	Platelet Adhesiveness	The process whereby PLATELETS adhere to something other than platelets, e.g., COLLAGEN; BASEMENT MEMBRANE; MICROFIBRILS; or other "foreign" surfaces.	Adhesiveness, Platelet,Adhesivenesses, Platelet,Platelet Adhesivenesses
D010980	Platelet Membrane Glycoproteins	Surface glycoproteins on platelets which have a key role in hemostasis and thrombosis such as platelet adhesion and aggregation. Many of these are receptors.	PM-GP,Platelet Glycoprotein,Platelet Membrane Glycoprotein,PM-GPs,Platelet Glycoproteins,Glycoprotein, Platelet,Glycoprotein, Platelet Membrane,Glycoproteins, Platelet,Glycoproteins, Platelet Membrane,Membrane Glycoprotein, Platelet,Membrane Glycoproteins, Platelet,PM GP
D011956	Receptors, Cell Surface	Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.	Cell Surface Receptor,Cell Surface Receptors,Hormone Receptors, Cell Surface,Receptors, Endogenous Substances,Cell Surface Hormone Receptors,Endogenous Substances Receptors,Receptor, Cell Surface,Surface Receptor, Cell
D001791	Blood Platelet Disorders	Disorders caused by abnormalities in platelet count or function.	Thrombocytopathy,Blood Platelet Disorder,Disorder, Blood Platelet,Disorders, Blood Platelet,Platelet Disorder, Blood,Platelet Disorders, Blood,Thrombocytopathies
D001792	Blood Platelets	Non-nucleated disk-shaped cells formed in the megakaryocyte and found in the blood of all mammals. They are mainly involved in blood coagulation.	Platelets,Thrombocytes,Blood Platelet,Platelet,Platelet, Blood,Platelets, Blood,Thrombocyte
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D005337	Fibrin	A protein derived from FIBRINOGEN in the presence of THROMBIN, which forms part of the blood clot.	Antithrombin I
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D001606	Bernard-Soulier Syndrome	A familial coagulation disorder characterized by a prolonged bleeding time, unusually large platelets, and impaired prothrombin consumption.	Giant Platelet Syndrome,Deficiency of Platelet Glycoprotein 1b,Glycoprotein Ib, Platelet, Deficiency Of,Platelet Glycoprotein 1b, Deficiency of,Platelet Glycoprotein Ib Deficiency,Von Willebrand Factor Receptor Deficiency,Bernard Soulier Syndrome,Platelet Syndromes, Giant,Syndrome, Bernard-Soulier,Syndrome, Giant Platelet,Syndromes, Giant Platelet
D018179	Receptors, Thrombin	A family of proteinase-activated receptors that are specific for THROMBIN. They are found primarily on PLATELETS and on ENDOTHELIAL CELLS. Activation of thrombin receptors occurs through the proteolytic action of THROMBIN, which cleaves the N-terminal peptide from the receptor to reveal a new N-terminal peptide that is a cryptic ligand for the receptor. The receptors signal through HETEROTRIMERIC GTP-BINDING PROTEINS. Small synthetic peptides that contain the unmasked N-terminal peptide sequence can also activate the receptor in the absence of proteolytic activity.	Thrombin Receptors,TRAP Peptide,Thrombin Receptor,Thrombin Receptor Activating Peptide Ligand,Thrombin Receptor Activating Peptides,Thrombin Receptor Activator Peptide,Peptide, TRAP,Receptor, Thrombin