Mutations of the dimerization site of glycoprotein (GP) VI result in abolished expression

•Here, we aimed to study the role of Glycoprotein VI (GPVI) dimerization in platelet activation in vivo. •The previously identified putative dimerization site of GPVI was mutated to disrupt the GPVI dimerization on the platelet surface. •Two different mutations of the GPVI dimerization site resulted in a loss of GPVI surface abundance in vivo. •Multivalent ligands (fibrillar collagen) of GPVI can elicit platelet activation also at very low GPVI density levels.