αIIbβ3 and Its Antagonism at the New Millennium

Abstract

SummaryBecause of its major role in regulating platelet functions and its prominence on the cell surface, integrin αIIbβ3 has been the subject of intensive investigations. Such studies have provided substantial insights into its structure-function relationships and have led to the development of anti-thrombotic drugs that target the receptor. Nevertheless, recent findings have indicated that our understanding of the structure and function of αIIbβ3 remains inadequate. This article addresses two aspects of still evolving αIIbβ3 function: 1) the interface between αIIbβ3 and the blood coagulation system, resulting from interaction of prothrombin with the receptor; and 2) the molecular basis for recognition of the RGD and the fibrinogen γ-chain peptide ligands by αIIbβ3. As illustrated by these two examples, there is still much to be learned about αIIbβ3 if we are to fully appreciate its functions and its potential as a therapeutic target.