IgG receptor FcRn large subunit p51 (FCGRT)

Binds to the Fc region of monomeric immunoglobulins gamma (PubMed:7964511, PubMed:10933786). Mediates the selective uptake of IgG from milk and assists newborn animals to acquire passive immunity.

IgG in the milk is bound at the apical surface of the intestinal epithelium. The consequent FcRn-IgG complexes are transcytosed across the intestinal epithelium and IgG is discharged from FcRn into blood or tissue fluids (By similarity).