1dpq
From Proteopedia
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|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[1dpk|1DPK]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1dpq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1dpq OCA], [http://www.ebi.ac.uk/pdbsum/1dpq PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1dpq RCSB]</span> | ||
}} | }} | ||
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==Overview== | ==Overview== | ||
A key step in the activation of heterodimeric integrin adhesion receptors is the transmission of an agonist-induced cellular signal from the short alpha- and/or beta-cytoplasmic tails to the extracellular domains of the receptor. The structural details of how the cytoplasmic tails mediate such an inside-out signaling process remain unclear. We report herein the NMR structures of a membrane-anchored cytoplasmic tail of the alpha(IIb)-subunit and of a mutant alpha(IIb)-cytoplasmic tail that renders platelet integrin alpha(IIb)beta(3) constitutively active. The structure of the wild-type alpha(IIb)-cytoplasmic tail reveals a "closed" conformation where the highly conserved N-terminal membrane-proximal region forms an alpha-helix followed by a turn, and the acidic C-terminal loop interacts with the N-terminal helix. The structure of the active mutant is significantly different, having an "open" conformation where the interactions between the N-terminal helix and C-terminal region are abolished. Consistent with these structural differences, the two peptides differ in function: the wild-type peptide suppressed alpha(IIb)beta(3) activation, whereas the mutant peptide did not. These results provide an atomic explanation for extensive biochemical/mutational data and support a conformation-based "on/off switch" model for integrin activation. | A key step in the activation of heterodimeric integrin adhesion receptors is the transmission of an agonist-induced cellular signal from the short alpha- and/or beta-cytoplasmic tails to the extracellular domains of the receptor. The structural details of how the cytoplasmic tails mediate such an inside-out signaling process remain unclear. We report herein the NMR structures of a membrane-anchored cytoplasmic tail of the alpha(IIb)-subunit and of a mutant alpha(IIb)-cytoplasmic tail that renders platelet integrin alpha(IIb)beta(3) constitutively active. The structure of the wild-type alpha(IIb)-cytoplasmic tail reveals a "closed" conformation where the highly conserved N-terminal membrane-proximal region forms an alpha-helix followed by a turn, and the acidic C-terminal loop interacts with the N-terminal helix. The structure of the active mutant is significantly different, having an "open" conformation where the interactions between the N-terminal helix and C-terminal region are abolished. Consistent with these structural differences, the two peptides differ in function: the wild-type peptide suppressed alpha(IIb)beta(3) activation, whereas the mutant peptide did not. These results provide an atomic explanation for extensive biochemical/mutational data and support a conformation-based "on/off switch" model for integrin activation. | ||
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| - | ==Disease== | ||
| - | Known diseases associated with this structure: Glanzmann thrombasthenia, type A OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=607759 607759]], Thrombocytopenia, neonatal alloimmune OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=607759 607759]] | ||
==About this Structure== | ==About this Structure== | ||
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[[Category: helix]] | [[Category: helix]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 19:46:16 2008'' |
Revision as of 16:46, 30 March 2008
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| Related: | 1DPK
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
SOLUTION STRUCTURE OF THE CONSTITUTIVELY ACTIVE MUTANT OF THE INTEGRIN ALPHA IIB CYTOPLASMIC DOMAIN.
Overview
A key step in the activation of heterodimeric integrin adhesion receptors is the transmission of an agonist-induced cellular signal from the short alpha- and/or beta-cytoplasmic tails to the extracellular domains of the receptor. The structural details of how the cytoplasmic tails mediate such an inside-out signaling process remain unclear. We report herein the NMR structures of a membrane-anchored cytoplasmic tail of the alpha(IIb)-subunit and of a mutant alpha(IIb)-cytoplasmic tail that renders platelet integrin alpha(IIb)beta(3) constitutively active. The structure of the wild-type alpha(IIb)-cytoplasmic tail reveals a "closed" conformation where the highly conserved N-terminal membrane-proximal region forms an alpha-helix followed by a turn, and the acidic C-terminal loop interacts with the N-terminal helix. The structure of the active mutant is significantly different, having an "open" conformation where the interactions between the N-terminal helix and C-terminal region are abolished. Consistent with these structural differences, the two peptides differ in function: the wild-type peptide suppressed alpha(IIb)beta(3) activation, whereas the mutant peptide did not. These results provide an atomic explanation for extensive biochemical/mutational data and support a conformation-based "on/off switch" model for integrin activation.
About this Structure
1DPQ is a Single protein structure of sequence from [1]. Full crystallographic information is available from OCA.
Reference
A structural basis for integrin activation by the cytoplasmic tail of the alpha IIb-subunit., Vinogradova O, Haas T, Plow EF, Qin J, Proc Natl Acad Sci U S A. 2000 Feb 15;97(4):1450-5. PMID:10677482
Page seeded by OCA on Sun Mar 30 19:46:16 2008
