pIgR: Proteins and Enzymes

pIgR (Polymeric Immunoglobulin Receptor) is a 100-kDa type I transmembrane glycoprotein. The extracellular region consists of five Ig-like domains and a sixth non-Ig domain that connects to the membrane region. pIgR is expressed on secretory epithelial cells of exocrine tissues. It functions as a carrier that transports IgA and IgM across epithelium.