Identification of β1,3-galactosyltransferases responsible for biosynthesis of insect complex-type N-glycans containing a T-antigen unit in the honeybee.
Honeybees (Apis mellifera) produce unique complex-type N-glycans bearing a Galβ1-3GalNAc (T-antigen) unit, and honeybee-specific N-glycans are linked to royal jelly glycoproteins. In this study, we identified two novel honeybee β1,3-galactosyltransferase (β1,3-GalT) genes responsible for biosynthesis of the T-antigen in insect N-glycans. The products of the two putative β1,3-GalT genes (β1,3-GalT1 and β1,3-GalT2), which were expressed in Sf21 insect cells, transferred galactose (Gal) residues to GalNAc2GlcNAc2Man3GlcNAc2-PA to form the Galβ1-3GalNAc unit, indicating that the identified genes were involved in biosynthesis of the β1-3 Gal-containing N-glycan. Therefore, using biochemistry and molecular biology techniques, we revealed a unique N-glycan biosynthesis mechanism in the cephalic region of honeybees, which has not previously been found in other animal or plant cells.
Department of Bioinformatics, Faculty of Engineering, Soka University, 1-236 Tangi-cho, Tokyo, Japan.
Tomomi
T
Ichimiya
Megumi
M
Maeda
Shou
S
Sakamura
Masato
M
Kanazawa
Shoko
S
Nishihara
Yoshinobu
Y
Kimura
D000595:Amino Acid Sequence; D000818:Animals; D000957:Antigens, Viral, Tumor / Q000378:metabolism*; D001516:Bees / Q000201:enzymology* / Q000235:genetics; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D003001:Cloning, Molecular; D029721:Drosophila Proteins / Q000737:chemistry; D005690:Galactose / Q000378:metabolism; D005700:Galactosyltransferases / Q000235:genetics / Q000378:metabolism*; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D011134:Polysaccharides / Q000096:biosynthesis* / Q000737:chemistry; D017386:Sequence Homology, Amino Acid
D000957:Antigens, Viral, Tumor; D029721:Drosophila Proteins; D019476:Insect Proteins; D011134:Polysaccharides; D005700:Galactosyltransferases; D005690:Galactose