The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
 
 
 

Platelet GPIb-V-IX complex. Structure, function, physiology, and pathology.

In the early phase of primary hemostasis, platelets adhere to damaged vessel wall by binding via the platelet glycoprotein (GP) Ib-V-IX complex to von Willebrand factor (vWf) exposed on the subendothelium. The complex is composed of four glycoprotein subunits, GPIb alpha, GPIb beta, GPIX and GPV, each with a variable number of leucine-rich repeats. GPIb alpha and GPIb beta are linked by a disulphide bridge while GPIX and GPV associate noncovalently with the complex. The study of defects in the expression of the GPIb-V-IX complex at the platelet surface leading to pathological disorders, like Bernard-Soulier syndrome (BSS), or in the affinity of platelets for vWf, like pseudo-von Willebrand disease, has helped to delineate the binding site for vWf on GPIb alpha. However, the mechanism by which the complex binds to vWf has not yet been elucidated but it must involve changes in the conformation of the molecules as no interaction between platelets and vWf occurs in the plasma. The GPIb-V-IX complex has a binding site for thrombin on GPIb alpha which participates in the platelet activation by that agonist. GPV is also cleaved by thrombin but the function of this proteolysis is not clear. The platelet response to thrombin is slower and weaker when the thrombin binding site on GPIb alpha is blocked or cleaved or when the GPIb-V-IX complex is not expressed on the platelet surface as in classic BSS. At low doses of thrombin, the rapid activation of the platelets via the seven-transmembrane thrombin receptor is dependent on the presence of the GPIb-V-IX complex.[1]

References

  1. Platelet GPIb-V-IX complex. Structure, function, physiology, and pathology. Clemetson, K.J., Clemetson, J.M. Semin. Thromb. Hemost. (1995) [Pubmed]
 
WikiGenes - Universities