| Structural highlights
Disease
[VWF_HUMAN] Defects in VWF are the cause of von Willebrand disease type 1 (VWD1) [MIM:193400]. A common hemorrhagic disorder due to defects in von Willebrand factor protein and resulting in impaired platelet aggregation. Von Willebrand disease type 1 is characterized by partial quantitative deficiency of circulating von Willebrand factor, that is otherwise structurally and functionally normal. Clinical manifestations are mucocutaneous bleeding, such as epistaxis and menorrhagia, and prolonged bleeding after surgery or trauma.[1] [2] Defects in VWF are the cause of von Willebrand disease type 2 (VWD2) [MIM:613554]. A hemorrhagic disorder due to defects in von Willebrand factor protein and resulting in impaired platelet aggregation. Von Willebrand disease type 2 is characterized by qualitative deficiency and functional anomalies of von Willebrand factor. It is divided in different subtypes including 2A, 2B, 2M and 2N (Normandy variant). The mutant VWF protein in types 2A, 2B and 2M are defective in their platelet-dependent function, whereas the mutant protein in type 2N is defective in its ability to bind factor VIII. Clinical manifestations are mucocutaneous bleeding, such as epistaxis and menorrhagia, and prolonged bleeding after surgery or trauma. Defects in VWF are the cause of von Willebrand disease type 3 (VWD3) [MIM:277480]. A severe hemorrhagic disorder due to a total or near total absence of von Willebrand factor in the plasma and cellular compartments, also leading to a profound deficiency of plasmatic factor VIII. Bleeding usually starts in infancy and can include epistaxis, recurrent mucocutaneous bleeding, excessive bleeding after minor trauma, and hemarthroses. [GP1BA_HUMAN] Genetic variations in GP1BA may be a cause of susceptibility to non-arteritic anterior ischemic optic neuropathy (NAION) [MIM:258660]. NAION is an ocular disease due to ischemic injury to the optic nerve. It usually affects the optic disk and leads to visual loss and optic disk swelling of a pallid nature. Visual loss is usually sudden, or over a few days at most and is usually permanent, with some recovery possibly occurring within the first weeks or months. Patients with small disks having smaller or non-existent cups have an anatomical predisposition for non-arteritic anterior ischemic optic neuropathy. As an ischemic episode evolves, the swelling compromises circulation, with a spiral of ischemia resulting in further neuronal damage.[3] Defects in GP1BA are a cause of Bernard-Soulier syndrome (BSS) [MIM:231200]; also known as giant platelet disease (GPD). BSS patients have unusually large platelets and have a clinical bleeding tendency.[4] [5] [6] [7] [8] [9] Defects in GP1BA are the cause of benign mediterranean macrothrombocytopenia (BMM) [MIM:153670]; also known as autosomal dominant benign Bernard-Soulier syndrome. BMM is characterized by mild or no clinical symptoms, normal platelet function, and normal megakaryocyte count.[10] Defects in GP1BA are the cause of pseudo-von Willebrand disease (VWDP) [MIM:177820]. A bleeding disorder is caused by an increased affinity of GP-Ib for soluble vWF resulting in impaired hemostatic function due to the removal of vWF from the circulation.[11] [12] [13] [14]
Function
[VWF_HUMAN] Important in the maintenance of hemostasis, it promotes adhesion of platelets to the sites of vascular injury by forming a molecular bridge between sub-endothelial collagen matrix and platelet-surface receptor complex GPIb-IX-V. Also acts as a chaperone for coagulation factor VIII, delivering it to the site of injury, stabilizing its heterodimeric structure and protecting it from premature clearance from plasma. [GP1BA_HUMAN] 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.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The adhesion of platelets to the subendothelium of blood vessels at sites of vascular injury under high shear conditions is mediated by a direct interaction between the platelet receptor glycoprotein Ibalpha (GpIbalpha) and the A1 domain of the von Willebrand factor (VWF). Here we report the 2.6-A crystal structure of a complex comprised of the extracellular domain of GpIbalpha and the wild-type A1 domain of VWF. A direct comparison of this structure to a GpIbalpha-A1 complex containing "gain-of-function" mutations, A1-R543Q and GpIbalpha-M239V, reveals specific structural differences between these complexes at sites near the two GpIbalpha-A1 binding interfaces. At the smaller interface, differences in interaction show that the alpha1-beta2 loop of A1 serves as a conformational switch, alternating between an open alpha1-beta2 isomer that allows faster dissociation of GpIbalpha-A1, as observed in the wild-type complex, and an extended isomer that favors tight association as seen in the complex containing A1 with a type 2B von Willebrand Disease (VWD) mutation associated with spontaneous binding to GpIbalpha. At the larger interface, differences in interaction associated with the GpIbalpha-M239V platelet-type VWD mutation are minor and localized but feature discrete gamma-turn conformers at the loop end of the beta-hairpin structure. The beta-hairpin, stabilized by a strong classic gamma-turn as seen in the mutant complex, relates to the increased affinity of A1 binding, and the beta-hairpin with a weak inverse gamma-turn observed in the wild-type complex corresponds to the lower affinity state of GpIbalpha. These findings provide important details that add to our understanding of how both type 2B and platelet-type VWD mutations affect GpIbalpha-A1 binding affinity.
Crystal structure of the wild-type von Willebrand factor A1-glycoprotein Ibalpha complex reveals conformation differences with a complex bearing von Willebrand disease mutations.,Dumas JJ, Kumar R, McDonagh T, Sullivan F, Stahl ML, Somers WS, Mosyak L J Biol Chem. 2004 May 28;279(22):23327-34. Epub 2004 Mar 23. PMID:15039442[15]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Allen S, Abuzenadah AM, Hinks J, Blagg JL, Gursel T, Ingerslev J, Goodeve AC, Peake IR, Daly ME. A novel von Willebrand disease-causing mutation (Arg273Trp) in the von Willebrand factor propeptide that results in defective multimerization and secretion. Blood. 2000 Jul 15;96(2):560-8. PMID:10887119
- ↑ Bodo I, Katsumi A, Tuley EA, Eikenboom JC, Dong Z, Sadler JE. Type 1 von Willebrand disease mutation Cys1149Arg causes intracellular retention and degradation of heterodimers: a possible general mechanism for dominant mutations of oligomeric proteins. Blood. 2001 Nov 15;98(10):2973-9. PMID:11698279
- ↑ Salomon O, Rosenberg N, Steinberg DM, Huna-Baron R, Moisseiev J, Dardik R, Goldan O, Kurtz S, Ifrah A, Seligsohn U. Nonarteritic anterior ischemic optic neuropathy is associated with a specific platelet polymorphism located on the glycoprotein Ibalpha gene. Ophthalmology. 2004 Jan;111(1):184-8. PMID:14711733 doi:10.1016/j.ophtha.2003.05.006
- ↑ Miller JL, Lyle VA, Cunningham D. Mutation of leucine-57 to phenylalanine in a platelet glycoprotein Ib alpha leucine tandem repeat occurring in patients with an autosomal dominant variant of Bernard-Soulier disease. Blood. 1992 Jan 15;79(2):439-46. PMID:1730088
- ↑ Ware J, Russell SR, Marchese P, Murata M, Mazzucato M, De Marco L, Ruggeri ZM. Point mutation in a leucine-rich repeat of platelet glycoprotein Ib alpha resulting in the Bernard-Soulier syndrome. J Clin Invest. 1993 Sep;92(3):1213-20. PMID:7690774 doi:http://dx.doi.org/10.1172/JCI116692
- ↑ Simsek S, Noris P, Lozano M, Pico M, von dem Borne AE, Ribera A, Gallardo D. Cys209 Ser mutation in the platelet membrane glycoprotein Ib alpha gene is associated with Bernard-Soulier syndrome. Br J Haematol. 1994 Dec;88(4):839-44. PMID:7819107
- ↑ de la Salle C, Baas MJ, Lanza F, Schwartz A, Hanau D, Chevalier J, Gachet C, Briquel ME, Cazenave JP. A three-base deletion removing a leucine residue in a leucine-rich repeat of platelet glycoprotein Ib alpha associated with a variant of Bernard-Soulier syndrome (Nancy I). Br J Haematol. 1995 Feb;89(2):386-96. PMID:7873390
- ↑ Kenny D, Jonsson OG, Morateck PA, Montgomery RR. Naturally occurring mutations in glycoprotein Ibalpha that result in defective ligand binding and synthesis of a truncated protein. Blood. 1998 Jul 1;92(1):175-83. PMID:9639514
- ↑ Koskela S, Partanen J, Salmi TT, Kekomaki R. Molecular characterization of two mutations in platelet glycoprotein (GP) Ib alpha in two Finnish Bernard-Soulier syndrome families. Eur J Haematol. 1999 Mar;62(3):160-8. PMID:10089893
- ↑ Savoia A, Balduini CL, Savino M, Noris P, Del Vecchio M, Perrotta S, Belletti S, Poggi, Iolascon A. Autosomal dominant macrothrombocytopenia in Italy is most frequently a type of heterozygous Bernard-Soulier syndrome. Blood. 2001 Mar 1;97(5):1330-5. PMID:11222377
- ↑ Matsubara Y, Murata M, Sugita K, Ikeda Y. Identification of a novel point mutation in platelet glycoprotein Ibalpha, Gly to Ser at residue 233, in a Japanese family with platelet-type von Willebrand disease. J Thromb Haemost. 2003 Oct;1(10):2198-205. PMID:14521605
- ↑ Miller JL, Cunningham D, Lyle VA, Finch CN. Mutation in the gene encoding the alpha chain of platelet glycoprotein Ib in platelet-type von Willebrand disease. Proc Natl Acad Sci U S A. 1991 Jun 1;88(11):4761-5. PMID:2052556
- ↑ Murata M, Russell SR, Ruggeri ZM, Ware J. Expression of the phenotypic abnormality of platelet-type von Willebrand disease in a recombinant glycoprotein Ib alpha fragment. J Clin Invest. 1993 May;91(5):2133-7. PMID:8486780 doi:http://dx.doi.org/10.1172/JCI116438
- ↑ Russell SD, Roth GJ. Pseudo-von Willebrand disease: a mutation in the platelet glycoprotein Ib alpha gene associated with a hyperactive surface receptor. Blood. 1993 Apr 1;81(7):1787-91. PMID:8384898
- ↑ Dumas JJ, Kumar R, McDonagh T, Sullivan F, Stahl ML, Somers WS, Mosyak L. Crystal structure of the wild-type von Willebrand factor A1-glycoprotein Ibalpha complex reveals conformation differences with a complex bearing von Willebrand disease mutations. J Biol Chem. 2004 May 28;279(22):23327-34. Epub 2004 Mar 23. PMID:15039442 doi:10.1074/jbc.M401659200
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