2vdq: Difference between revisions

==Disease==

[[http://www.uniprot.org/uniprot/ITA2B_HUMAN ITA2B_HUMAN]] Defects in ITGA2B are a cause of Glanzmann thrombasthenia (GT) [MIM:[http://omim.org/entry/273800 273800]]; also known as thrombasthenia of Glanzmann and Naegeli. GT is the most common inherited disease of platelets. It is an autosomal recessive disorder characterized by mucocutaneous bleeding of mild-to-moderate severity and the inability of this integrin to recognize macromolecular or synthetic peptide ligands. GT has been classified clinically into types I and II. In type I, platelets show absence of the glycoprotein IIb/beta-3 complexes at their surface and lack fibrinogen and clot retraction capability. In type II, the platelets express the glycoprotein IIb/beta-3 complex at reduced levels (5-20% controls), have detectable amounts of fibrinogen, and have low or moderate clot retraction capability. The platelets of GT 'variants' have normal or near normal (60-100%) expression of dysfunctional receptors.<ref>PMID:8282784</ref><ref>PMID:7508443</ref><ref>PMID:7706461</ref><ref>PMID:8704171</ref><ref>PMID:9215749</ref><ref>PMID:9473221</ref><ref>PMID:9763559</ref><ref>PMID:9722314</ref><ref>PMID:9734640</ref><ref>PMID:9920835</ref><ref>PMID:10607701</ref><ref>PMID:11798398</ref><ref>PMID:12181054</ref><ref>PMID:12083483</ref><ref>PMID:12424194</ref><ref>PMID:12506038</ref><ref>PMID:15099289</ref><ref>PMID:15219201</ref><ref>PMID:17018384</ref> [[http://www.uniprot.org/uniprot/ITB3_HUMAN ITB3_HUMAN]] Defects in ITGB3 are a cause of Glanzmann thrombasthenia (GT) [MIM:[http://omim.org/entry/273800 273800]]; also known as thrombasthenia of Glanzmann and Naegeli. GT is the most common inherited disease of platelets. It is an autosomal recessive disorder characterized by mucocutaneous bleeding of mild-to-moderate severity and the inability of this integrin to recognize macromolecular or synthetic peptide ligands. GT has been classified clinically into types I and II. In type I, platelets show absence of the glycoprotein IIb/beta-3 complexes at their surface and lack fibrinogen and clot retraction capability. In type II, the platelets express the glycoprotein IIb/beta-3 complex at reduced levels (5-20% controls), have detectable amounts of fibrinogen, and have low or moderate clot retraction capability. The platelets of GT 'variants' have normal or near normal (60-100%) expression of dysfunctional receptors.<ref>PMID:2392682</ref><ref>PMID:1371279</ref><ref>PMID:1602006</ref><ref>PMID:1438206</ref><ref>PMID:8781422</ref><ref>PMID:9376589</ref><ref>PMID:9215749</ref><ref>PMID:9790984</ref><ref>PMID:9684783</ref><ref>PMID:10233432</ref><ref>PMID:11588040</ref><ref>PMID:11897046</ref><ref>PMID:12083483</ref><ref>PMID:12353082</ref><ref>PMID:15583747</ref><ref>PMID:15634267</ref><ref>PMID:15748237</ref>  

[[http://www.uniprot.org/uniprot/ITA2B_HUMAN ITA2B_HUMAN]] Integrin alpha-IIb/beta-3 is a receptor for fibronectin, fibrinogen, plasminogen, prothrombin, thrombospondin and vitronectin. It recognizes the sequence R-G-D in a wide array of ligands. It recognizes the sequence H-H-L-G-G-G-A-K-Q-A-G-D-V in fibrinogen gamma chain. Following activation integrin alpha-IIb/beta-3 brings about platelet/platelet interaction through binding of soluble fibrinogen. This step leads to rapid platelet aggregation which physically plugs ruptured endothelial cell surface. [[http://www.uniprot.org/uniprot/ITB3_HUMAN ITB3_HUMAN]] Integrin alpha-V/beta-3 is a receptor for cytotactin, fibronectin, laminin, matrix metalloproteinase-2, osteopontin, osteomodulin, prothrombin, thrombospondin, vitronectin and von Willebrand factor. Integrin alpha-IIb/beta-3 is a receptor for fibronectin, fibrinogen, plasminogen, prothrombin, thrombospondin and vitronectin. Integrins alpha-IIb/beta-3 and alpha-V/beta-3 recognize the sequence R-G-D in a wide array of ligands. Integrin alpha-IIb/beta-3 recognizes the sequence H-H-L-G-G-G-A-K-Q-A-G-D-V in fibrinogen gamma chain. Following activation integrin alpha-IIb/beta-3 brings about platelet/platelet interaction through binding of soluble fibrinogen. This step leads to rapid platelet aggregation which physically plugs ruptured endothelial surface. In case of HIV-1 infection, the interaction with extracellular viral Tat protein seems to enhance angiogenesis in Kaposi's sarcoma lesions.

[[2vdq]] is a 5 chain structure with sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2VDQ OCA].

*[[Integrin|Integrin]]

 

==Reference==

<ref group="xtra">PMID:018710925</ref><ref group="xtra">PMID:015378069</ref><references group="xtra"/><references/>

[[Category: Springer, T A.]]

[[Category: Xiao, T.]]

[[Category: Zhu, J.]]

[[Category: Transmembrane]]