title: Glycoprotein VI oligomerization in cell lines and platelets.
abstract: BACKGROUND
  Glycoprotein VI (GPVI) is a physiologic receptor for collagen expressed at the surface of platelets and megakaryocytes. Constitutive dimerization of GPVI has been proposed as being necessary for the interaction with collagen, although direct evidence of dimerization has not been reported in cell lines or platelets.
  
  
  OBJECTIVE
  To investigate oligomerization of GPVI in transfected cell lines and in platelets under non-stimulated conditions.
  
  
  RESULTS
  By using a combination of molecular and biochemical techniques, we demonstrate that GPVI association occurs at the surface of transfected 293T cells under basal conditions, through an interaction at the extracellular domain of the receptor. Bioluminescence resonance energy transfer was used to confirm oligomerization of GPVI under these conditions. A chemical crosslinker was used to detect constitutive oligomeric forms of GPVI at the surface of platelets, which contain the Fc receptor (FcR) gamma-chain.
  
  
  CONCLUSIONS
  The present results directly demonstrate GPVI-FcR gamma-chain oligomerization at the surface of the platelet, and thereby add to the growing evidence that oligomerization of GPVI may be a prerequisite for binding of the receptor to collagen, and therefore for proper functioning of platelets upon vascular damage.
authors: Institute of Biomedical Research, Medical School, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
authors: Oscar
authors: O
authors: Berlanga
authors: Institute of Biomedical Research, Medical School, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
authors: Teresa
authors: T
authors: Bori-Sanz
authors: Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headington, University of Oxford, Oxford OX3 9DS, UK.
authors: John R
authors: JR
authors: James
authors: Institute of Biomedical Research, Medical School, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
authors: Jon
authors: J
authors: Frampton
authors: Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headington, University of Oxford, Oxford OX3 9DS, UK.
authors: Simon J
authors: SJ
authors: Davis
authors: Institute of Biomedical Research, Medical School, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
authors: Michael G
authors: MG
authors: Tomlinson
authors: Institute of Biomedical Research, Medical School, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
authors: Steve P
authors: SP
authors: Watson
mesh_terms: D001483:Base Sequence; D001704:Biopolymers / Q000378:metabolism*; D001792:Blood Platelets / Q000378:metabolism*; D002460:Cell Line; D017931:DNA Primers; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D010980:Platelet Membrane Glycoproteins / Q000378:metabolism*
chemical_list: D001704:Biopolymers; D017931:DNA Primers; D010980:Platelet Membrane Glycoproteins