Japan Society for Bioscience, Biotechnology, and Agrochemistry Acta Medica Okayama 0916-8451 71 4 2007 Evidence for new beta 1-3 galactosyltransferase activity involved in biosynthesis of unusual N-glycan harboring T-antigen in Apis mellifera 1111 1114 EN Yoshinobu Kimura Sho Sakamura Takayuki Ushijima Yoichiro Hama Hiroyuki Kajiura Kazuhito Fujiyama Kiyoshi Okihara Ken Hashimoto Hiroyuki Sugimoto Hideo Yamada In a previous study (Y. Kimura et al., Biosci. Biotechnol Biochem., 70, 2583-2587, 2006), we found that new complex type N-glycans harboring Thomsen-Friedenreich antigen (Ga1 beta 1-3GalNAc) unit occur on royal jelly glycoproteins, suggesting the involvement of a new beta 1-3galactosyltransferase in the synthesis of the unusual complex type N-glycans. So far, such beta 1-3galactosyltransferase activity, which can transfer galactosyl residues with the beta 1-3 linkage to beta 1-4 GalNAc residues in N-glycan, has not been found among any eucaryotic cells. But using GalNAc(2)GlcNAc(2)Man(3)-GlcNAc(2)-PA as acceptor N-glycan, we detected the beta 1-3 galactosyltransferase activity in membrane fraction prepared from honeybee cephalic portions. This result indicates that honeybee expresses a unique beta 1-3 galactosyltransferase involved in biosynthesis of the unusual N-glycan containing a tumor related antigen in the hypopharyngeal gland. No potential conflict of interest relevant to this article was reported.