Glycoprotein VI (platelet) also known as GPVI is a glycoprotein receptor for collagen which is expressed in platelets. In humans, glycoprotein VI is encoded by the GPVI gene.

Glycoprotein VI (GP6) is a 58-kD platelet membrane glycoprotein that plays a crucial role in the collagen-induced activation and aggregation of platelets. Upon injury to the vessel wall and subsequent damage to the endothelial lining, exposure of the subendothelial matrix to blood flow results in deposition of platelets. Collagen fibers are the most thrombogenic macromolecular components of the extracellular matrix, with collagen types I, III, and VI being the major forms found in blood vessels. Platelet interaction with collagen occurs as a 2-step procedure: (1) the initial adhesion to collagen is followed by (2) an activation step leading to platelet secretion, recruitment of additional platelets, and aggregation. In physiologic conditions, the resulting platelet plug is the initial hemostatic event limiting blood loss. However, exposure of collagen after rupture of atherosclerotic plaques is a major stimulus of thrombus formation associated with myocardial infarction or stroke (Jandrot-Perrus et al., 2000 [PubMed 10961879]).[supplied by OMIM, Mar 2008].
Function: Collagen receptor involved in collagen-induced platelet adhesion and activation. Plays a key role in platelet procoagulant activity and subsequent thrombin and fibrin formation. This procoagulant function may contribute to arterial and venous thrombus formation. The signaling pathway involves the FcR gamma-chain, the Src kinases (likely Fyn/Lyn), the adapter protein LAT and leads to the activation of phospholipase C gamma2.