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Direct interaction between FcγRI (CD64) and periplakin controls receptor endocytosis and ligand binding capacity

2004; National Academy of Sciences; Volume: 101; Issue: 28 Linguagem: Inglês

10.1073/pnas.0401217101

1091-6490

Jeffrey M. Beekman, Jantine E. Bakema, Jan G. J. van de Winkel, Jeanette H.W. Leusen,

Autoimmune Bullous Skin Diseases

FcγRI depends for its biological function on both the intracellular domain of the α-chain and associated Fc receptor (FcR) γ-chains. However, functional protein effectors of FcγRI's intracellular domain have not been identified. In this study, we identified periplakin (PPL) as a selective interacting protein for the intracellular tail of FcγRI but no other activatory FcRs. The interaction was confirmed by coimmunoprecipitation and blot-overlay assays. PPL and FcγRI colocalized at the plasma membrane in monocytes and cell transfectants, and both were up-regulated by IFN-γ. By expressing C-terminal PPL in transfectants, we established a pivotal role for this protein in FcγRI ligand binding, endocytosis, and antigen presentation. These data illustrate that intracellular protein interactions with a multisubunit FcR α-chain can confer unique properties to the receptor.