Receptors polymeric immunoglobulin
receptors, polymeric immunoglobulin
Specialised fc receptors (receptors, fc) for polymeric immunoglobulins, which mediate transcytosis of polymeric igA and igM into external secretions. They are found on the surfaces of epithelial cells and hepatocytes. After binding to IgA, the receptor-ligand complex undergoes endocytosis, transport by vesicle, and secretion into the lumen by exocytosis. Before release, the part of the receptor (secretory component) that is bound to IgA is proteolytically cleaved from its transmembrane tail.