Although core alpha 1,6-fucosylation is commonly observed in N-glycans of both vertebrates and invertebrates, the responsible enzyme, alpha 1,6-fucosyltransferase, has been much less characterized in invertebrates compared to vertebrates. To investigate the functions of alpha 1,6-fucosyltransferase in insects, we cloned the cDNA for the alpha 1,6-fucosyltransferase from Bombyx mori (Bm alpha 1,6FucT) and characterized the recombinant enzyme prepared using insect cell lines. The coding region of Bm alpha 1,6FucT consists of 1737 bp that code for 578 amino acids of the deduced amino acid sequence, showing significant similarity to other alpha 1,6-fucosyltransferases. Enzyme activity assays demonstrated that Bm alpha 1,6FucT is enzymatically active in spite of being less active compared to the human enzyme. The findings also indicate that Bm alpha 1,6FucT, unlike human enzyme, is N-glycosylated and forms a disulfide-bonded homodimer. These findings contribute to a better understanding of roles of alpha 1,6-fucosylation in invertebrates and also to the development of the more efficient engineering of N-glycosylation of recombinant glycoproteins in insect cells. (C) 2014 Elsevier Inc. All rights reserved.