Protein-coding gene in the species Homo sapiens
Polymeric immunoglobulin receptor (pIgR) is a transmembrane protein that in humans is encoded by the PIGR gene.[5] It is an Fc receptor which facilitates the transcytosis of the soluble polymeric isoforms of immunoglobulin A and immunoglobulin M (pIg) and immune complexes. pIgRs are mainly located on the epithelial lining of mucosal surfaces of the gastrointestinal tract. The composition of the receptor is complex, including 6 immunoglobulin-like domains, a transmembrane region, and an intracellular domain.[6] pIgR expression is under the strong regulation of cytokines, hormones, and pathogenic stimuli.[6][7]