2l91: Difference between revisions
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== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[2l91]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2L91 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2L91 FirstGlance]. <br> | <table><tr><td colspan='2'>[[2l91]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2L91 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2L91 FirstGlance]. <br> | ||
</td></tr><tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2l91 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2l91 OCA], [https://pdbe.org/2l91 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2l91 RCSB], [https://www.ebi.ac.uk/pdbsum/2l91 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2l91 ProSAT]</span></td></tr> | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</td></tr> | ||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2l91 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2l91 OCA], [https://pdbe.org/2l91 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2l91 RCSB], [https://www.ebi.ac.uk/pdbsum/2l91 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2l91 ProSAT]</span></td></tr> | |||
</table> | </table> | ||
== Disease == | == Disease == |
Latest revision as of 08:40, 15 May 2024
Structure of the Integrin beta3 (A711P,K716A) Transmembrane SegmentStructure of the Integrin beta3 (A711P,K716A) Transmembrane Segment
Structural highlights
DiseaseITB3_HUMAN Defects in ITGB3 are a cause of Glanzmann thrombasthenia (GT) [MIM: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.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] FunctionITB3_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. Publication Abstract from PubMedSide chains of Lys/Arg near transmembrane domain (TMD) membrane-water interfaces can 'snorkel', placing their positive charge near negatively charged phospholipid head groups; however, snorkelling's functional effects are obscure. Integrin beta TMDs have such conserved basic amino acids. Here we use NMR spectroscopy to show that integrin beta(3)(Lys 716) helps determine beta(3) TMD topography. The alpha(IotaIotab)beta(3) TMD structure indicates that precise beta(3) TMD crossing angles enable the assembly of outer and inner membrane 'clasps' that hold the alphabeta TMD together to limit transmembrane signalling. Mutation of beta(3)(Lys 716) caused dissociation of alpha(IotaIotab)beta(3) TMDs and integrin activation. To confirm that altered topography of beta(3)(Lys 716) mutants activated alpha(IotaIotab)beta(3), we used directed evolution of beta(3)(K716A) to identify substitutions restoring default state. Introduction of Pro(711) at the midpoint of beta(3) TMD (A711P) increased alpha(IotaIotab)beta(3) TMD association and inactivated integrin alpha(IotaIotab)beta(3)(A711P,K716A). beta(3)(Pro 711) introduced a TMD kink of 30 +/- 1 degrees precisely at the border of the outer and inner membrane clasps, thereby decoupling the tilt between these segments. Thus, widely occurring snorkelling residues in TMDs can help maintain TMD topography and membrane-embedding, thereby regulating transmembrane signalling. Basic amino-acid side chains regulate transmembrane integrin signalling.,Kim C, Schmidt T, Cho EG, Ye F, Ulmer TS, Ginsberg MH Nature. 2011 Dec 18;481(7380):209-13. doi: 10.1038/nature10697. PMID:22178926[18] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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