Binding of GPVI:Fc Epsilon R1 gamma receptor complex with collagen

GPVI receptor has little affinity for soluble forms of collagen but binds collagen fibrils. Recent structural models indicate that each GPVI receptor complex could bind up to 3 collagen fibrils (Jung & Moroi 2008). The Src family kinases Fyn and Lyn constitutively associate with the GPVI-FceRIgamma complex in platelets and initiate platelet activation through phosphorylation of the immunoreceptor tyrosine-based activation motif (ITAM) in the FceRIgamma chain, leading to binding and activation of the tyrosine kinase Syk. Downstream of Syk, a series of adapter molecules and effectors lead to platelet activation.

GPVI受体对可溶性形式的胶原蛋白亲和力较低，但能与胶原蛋白纤维结合。近期结构模型表明，每个GPVI受体复合体能够结合高达3根胶原蛋白纤维（Jung & Moroi 2008）。Src家族激酶Fyn和Lyn在血小板中持续与GPVI-FceRIgamma复合物结合，并通过磷酸化FceRIgamma链中的免疫受体酪氨酸激活基序（ITAM）启动血小板活化，进而导致酪氨酸激酶Syk的结合与活化。Syk下游，一系列适配分子和效应分子引发血小板活化。