STUDIES ON THE GLYCOPROTEIN ASSOCIATED WITH RH (RHESUS) BLOOD-GROUP ANTIGEN EXPRESSION IN THE HUMAN RED-BLOOD-CELL MEMBRANE

The blood group Rh antigens are associated with non-glycosylated 30-kD a erythrocyte membrane proteins (the Rh-30 polypeptides) and the Rh gl ycoprotein. We used antipeptide antibodies to study the Rh glycoprotei n in human erythrocyte membranes. The Rh glycoprotein was present in R h-null U+ve cells. However, the N-glycan chain of the Rh glycoprotein in Rh-null U+ve cells was smaller than in normal cells. In contrast, t he N-glycan chain of the Rh glycoprotein was larger than normal in gly cophorin B-deficient red cells. We suggest that this observation refle cts a lower rate of movement of newly synthesized Rh glycoprotein thro ugh intracellular membranes to the cell surface in the absence of glyc ophorin B, and that in normal red cells glycophorin B facilitates the movement of the Rh protein complex to the cell surface. Our results pr ovide evidence for the intracellular interaction of a least three prot eins, the Rh glycoprotein, Rh-30 polypeptides, and glycophorin B durin g the biosynthesis and cell surface expression of the Rh complex. Thes e observations are likely to be important for the successful design of expression systems for the blood group Rh antigens.