THE EFFECTS OF GLYCOPHORIN-A ON THE EXPRESSION OF THE HUMAN RED-CELL ANION TRANSPORTER (BAND 3) IN XENOPUS-OOCYTES

The effects of human red cell glycophorin A (GPA) on the translocation to the plasma membrane and anion transport activity of the human eryt hrocyte anion transporter (band 3; AE1) have been examined using the X enopus oocyte expression system. We show that band 3 accumulates stead ily at the oocyte surface with time in the presence or absence of GPA, but this occurs more quickly when GPA is coexpressed. The amount of b and 3 at the surface is determined by the concentrations of band 3 and GPA cRNA that are injected, with a higher proportion of total band 3 being translocated to the surface in the presence of GPA cRNA. The inc reased expression of DNDS-sensitive chloride transport is highly speci fic to GPA, and is not observed when the cRNA to the putative glycopho rin E or a very high concentration of the cRNA to glycophorin C an coe xpressed with band 3 in oocytes.