COMPLETE DEFICIENCY OF GLYCOPHORIN-A IN RED-BLOOD-CELLS FROM MICE WITH TARGETED INACTIVATION OF THE BAND-3 (AE1) GENE

Glycophorin A is the major transmembrane sialoglycoprotein of red bloo d cells. It has been shown to contribute to the expression of the MN a nd Wright blood group antigens, to act as a receptor for the malaria p arasite Plasmodium falciparum and Sendai virus, and along with the ani on transporter, band 3, may contribute to the mechanical properties of the red blood cell membrane. Several lines of evidence suggest a clos e interaction between glycophorin A and band 3 during their biosynthes is. Recently, we have generated mice where the band 3 expression was c ompletely eliminated by selective inactivation of the AE1 anion exchan ger gene, thus allowing us to study the effect of band 3 on the expres sion of red blood cell membrane proteins. In this report, we show that the band 3 -/- red blood cells contain protein 4.1, adducin, dematin, p55, and glycophorin C. In contrast, the band 3 -/- red blood cells a re completely devoid of glycophorin A (GPA), as assessed by Western bl ot and immunocytochemistry techniques, whereas the polymerase chain re action (PCR) confirmed the presence of GPA mRNA. Pulse-label and pulse -chase experiments show that GPA is not incorporated in the membrane a nd is rapidly degraded in the cytoplasm. Based on these findings and o ther published evidence, we propose that band 3 plays a chaperone-like role, which is necessary for the recruitment of GPA to the red blood cell plasma membrane. (C) 1998 by The American Society of Hematology.