High-affinity IgG Fc receptor I (FcγRI) (FcγRI)

High-affinity IgG Fc receptor I (FcγRI, also known as CD64 or hFcγRI) is the sole high-affinity receptor for IgG among Fcγ receptors, capable of binding monomeric IgG, particularly IgG1, with high affinity due to unique structural features like a hydrophobic pocket accommodating Leu235 of the Fc region and a shorter FG-loop in the D2 domain. It consists of three extracellular Ig-like domains (D1, D2, D3), forms a complex with an FcR γ-chain for signaling, and is expressed on macrophages, monocytes, neutrophils, eosinophils, and dendritic cells, with expression upregulated by interferons and IL-12. FcγRI mediates innate and adaptive immune responses through receptor clustering and signal transduction, playing key roles in immunity and links to autoimmune diseases, and its structure supports potential immunotherapy applications.

Other names

hFcγRICD64