The GPVI/Fc receptor γ-chain complex. (A) Organization of the GPVI/FcR γ-chain complex. GPVI consists of 2 Ig domains linked to a mucin-rich region that has a number of sites for O-linked glycosylation. The transmembrane domain has an arginine group that is required for the association with the FcR γ-chain through a salt bridge. The cytosolic tail consists of a number of domains as illustrated in panel B. The FcR γ-chain is present as a disulphide-linked homodimer and has 2 tyrosines in a conserved sequence known as an ITAM. GPVI is highly polymorphic and those sites that lead to amino acid changes (3-letter code) are shown. For further information see Croft et al.43 (B) Amino acid sequence of the cytosolic tail of GPVI showing the sites of interaction with the FcR γ-chain, calmodulin, and the SH3 domain of Src kinases. The amino acids following the proline-rich region are absent in the murine sequence.
