Integrin alpha 2B beta 3

Integrin alpha 2B beta 3 is the platelet-restricted heterodimer of CD41 and CD61, classically known as glycoprotein IIb/IIIa and the therapeutic target of abciximab. Structurally it combines an alpha-IIb chain cleaved into disulfide-linked heavy and light subunits with the beta-3 chain shared with alpha V beta 3. The receptor exists in equilibrium between bent and extended conformations; activation depends on inside-out signals delivered by talin-1 and kindlin-3 downstream of platelet agonists. Only the high-affinity state binds fibrinogen and von Willebrand factor to mediate aggregation. Mutations in either subunit cause Glanzmann thrombasthenia, and receptor occupancy and function are monitored during antiplatelet therapy.