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Platelet integrin α IIb β 3 : activation mechanisms
Author(s) -
MA Y.Q.,
QIN J.,
PLOW E. F.
Publication year - 2007
Publication title -
journal of thrombosis and haemostasis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.947
H-Index - 178
eISSN - 1538-7836
pISSN - 1538-7933
DOI - 10.1111/j.1538-7836.2007.02537.x
Subject(s) - integrin , microbiology and biotechnology , platelet , chemistry , cytoplasm , integrin, beta 6 , platelet activation , transmembrane protein , alpha (finance) , transmembrane domain , biophysics , biology , biochemistry , receptor , immunology , medicine , construct validity , nursing , patient satisfaction
Summary. Integrin α IIb β 3 plays a critical role in platelet aggregation, a central response in hemostasis and thrombosis. This function of α IIb β 3 depends upon a transition from a resting to an activated state such that it acquires the capacity to bind soluble ligands. Diverse platelet agonists alter the cytoplasmic domain of α IIb β 3 and initiate a conformational change that traverses the transmembrane region and ultimately triggers rearrangements in the extracellular domain to permit ligand binding. The membrane‐proximal regions of α IIb and β 3 cytoplasmic tails, together with the transmembrane segments of the subunits, contact each other to form a complex which restrains the integrin in the resting state. It is unclasping of this complex that induces integrin activation. This clasping/unclasping process is influenced by multiple cytoplasmic tail binding partners. Among them, talin appears to be a critical trigger of α IIb β 3 activation, but other binding partners, which function as activators or suppressors, are likely to act as co‐regulators of integrin activation.