High affinity receptor for the Fc region of immunoglobulins gamma. Functions in both innate and adaptive immune responses. Interacts with FCERG1; forms a functional signaling complex (By similarity). Interacts with FLNA; prevents FCGR1A degradation (By similarity). Interacts with EPB41L2, LAT and PPL. Interacts with HCK and LYN (By similarity). Stabilized at the cell membrane through interaction with FCER1G. Macrophage-specific. N-glycosylated. Phosphorylated on serine residues. According to PubMed:11911823, mice display altered endocytosis of monomeric IgG and impaired antibody-dependent killing of cells by macrophage. Antigen presentation is also affected and those mice develop only reduced inflammatory responses. An increased in IgG responses is also detected associated with an increased number of antibody-forming cells. PubMed:11911824, also reported that a variety of IgG2a-immune complex-dependent immune functions like protection against bacterial infection were impaired. Belongs to the immunoglobulin superfamily. FCGR1 family. It is uncertain whether Met-1 or Met-10 is the initiator.