Language

English

Publication Date

7-11-2024

Journal

Structure

DOI

10.1016/j.str.2024.03.006

PMID

38579706

PMCID

PMC11246237

PubMedCentral® Posted Date

7-11-2025

PubMedCentral® Full Text Version

Author MSS

Abstract

Integrin αIIbβ3 is the key receptor regulating platelet retraction and accumulation and a proven drug-target for antithrombotic therapies. Here we resolve the cryoEM structures of the full-length αIIbβ3, which covers three distinct states along the activation pathway. Firstly, we obtain the αIIbβ3 structure at 3Å resolution in the inactive state, revealing the overall topology of the heterodimer with the transmembrane (TM) helices and the ligand-binding domain tucked in a specific angle proximity to the TM region. After the addition of a Mn2+ agonist, we resolve two coexisting structures representing two new states between inactive and active state. Our structures show conformational changes of the αIIbβ3 activating trajectory and a unique twisting of the integrin legs, which is required for platelets accumulation. Our structure provides direct structural evidence for how the lower legs are involved in full-length integrin activation mechanisms and offers a new strategy to target the αIIbβ3 lower leg.

Keywords

Humans, Binding Sites, Cryoelectron Microscopy, Manganese, Models, Molecular, Platelet Glycoprotein GPIIb-IIIa Complex, Protein Binding, Protein Conformation, Protein Multimerization, Integrin beta3, Integrin alpha2

Published Open-Access

yes

nihms-1979309-f0006.jpg (134 kB)
Graphical Abstract

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