Braking platelet activation: deactivating the receptors

Abstract

Glycoprotein (GP) VI and Fc receptor FcγRIIa are 2 ITAM (immunoreceptor tyrosine-activation motif)–bearing platelet surface receptors. In this issue of Blood, Gardiner and colleagues show that activation of either receptor results in simultaneous proteolytic cleavage of GPVI ectodomain and FcγRIIa cytoplasmic tail, providing distinct mechanisms for their down-regulation on platelet activation.