THE CLONING AND EXPRESSION OF A HUMAN ALPHA-1,3 FUCOSYL-TRANSFERASE CAPABLE OF FORMING THE E-SELECTIN LIGAND

The polymerase chain reaction was used to amplify a novel fucosyltransferase cDNA (FucT-VI) from A431 and from HL60 cells. The amplified cDNA has a high degree of sequence identity to FucT-V and to FucT-III, and a much lower level of similiarity to FucT-IV. Transfection of the FucT-VI gene into mammalian cells confers α-1,3 fucosyltransferase activity to the cells, resulting in cell surface expression of Lewis x and sialyl-Lewis x carbohydrates. In contrast to FucT-IV activity, FucT-VI catalyzes the transfer of fucose from GDP-β-fucose to α-2,3 sialylated substrates. The substrate specificity of the FucT-VI gene product suggests that FucT-VI may be an enzyme involved in the biosynthesis of the E-Selectin ligand, sialyl-Lewis x, in myeloid cells. © 1992 Academic Press, Inc.