Xyloglucan fucosyltransferase, an enzyme involved in plant cell wall biosynthesis

Cell walls are crucial for development, signal transduction, and disease re sistance in plants. Cell walls are made of cellulose, hemicelluloses, and p ectins. Xyloglucan (XG), the principal load-bearing hemicellulose of dicoty ledonous plants. has a terminal fucosyl residue. A 60-kilodalton fucosyltra nsferase (FTase) that adds this residue was purified from pea epicotyls. Pe ptide sequence information from the pea FTase allowed the cloning of a homo logous gene, AtFT1, from Arabidopsis. Antibodies raised against recombinant AtFTase immunoprecipitate FTase enzyme activity from solubilized Arabidops is membrane proteins, and AtFT1 expressed in mammalian COS cells results in the presence of XG FTase activity in these cells.