FIGURE 4.

Fucosyltransferase activity in detergent extracts from tobacco BY2 cells expressing the AtFUT4.1 or AtFUT6 gene and from BY2 WT cells. Fucosyltransferase activity was monitored by measuring [¹⁴C]Fuc transfer onto AGPs from GDP-[¹⁴C]Fuc as described under “Experimental Procedures.” Enzyme sources were prepared from microsomal membranes solubilized with 0.5% digitonin from WT cells and transgenic cells. A–C show the fucosyltransferase activity resulting from using AGP substrate acceptors purified from wild type (AGPs-BY2WT), from cells expressing the AtFUT6 gene (AGPs-BY2:F6), and from cells expressing the AtFUT4.1 gene (AGPs-BY2:F4), respectively. All of the AGPs were used at 0, 50, and 100 μg/reaction. Each value is an average based on at least three experiment sets. The error bars represent the S.E.