A complete transmembrane coding region of human erythrocyte anion exchanger1 (AE1, band 3) and the full length of glycophorin A (GPA) were amplified by PCR amplification. The genes were subcloned into the baculovirus transfer vectors and expressed in Sf9 cells. Western blot showed a cross reaction between band 3 transmembrane domain and GPA. The yeast two-hybrid experiment confirmed the interaction between the two proteins.