FCGRT-B2M Heterodimer Protein, Cynomolgus (Biotinylated, HEK293, His-Avi)

The FCGRT protein is a cell surface receptor that plays a critical role in transferring passive humoral immunity from the mother to the newborn. It accomplishes this by binding to the Fc region of monomeric immunoglobulin gamma and facilitating its selective uptake from milk. Within the intestinal epithelium, the FCGRT-B2M heterodimer binds to IgG at the apical surface, forming FcRn-IgG complexes that are transcytosed across the epithelium, releasing IgG into the bloodstream or tissue fluids. This receptor continues to contribute to effective humoral immunity throughout life by recycling IgG and prolonging its half-life in circulation. Mechanistically, the binding of monomeric IgG to FCGRT-B2M in acidic endosomes of endothelial and hematopoietic cells enables the recycling of IgG to the cell surface for release into the circulation. Additionally, the FCGRT-B2M heterodimer plays a role in regulating the homeostasis of albumin, the most abundant circulating protein, by interacting with it. The FCGRT-B2M complex consists of two subunits, p51 and p14 (equivalent to beta-2-microglobulin), forming an MHC class I-like heterodimer.