title: Drosophila beta 1,4-N-acetylgalactosaminyltransferase-A synthesizes the LacdiNAc structures on several glycoproteins and glycosphingolipids.
abstract: The GalNAcbeta1,4GlcNAc (LacdiNAc or LDN) structure is a more common structural feature in invertebrate glycoconjugates when compared with the Galbeta1,4GlcNAc structure. Recently, beta1,4-N-acetylgalactosaminyltransferase (beta4GalNAcT) was identified in some invertebrates including Drosophila. However, the LDN structure has not been reported in Drosophila, and the biological function of LDN remains to be determined. In this study, we examined acceptor substrate specificity of Drosophila beta4GalNAcTA by using some N- and O-glycans on glycoproteins and neutral glycosphingolipids (GSLs). GalNAc was efficiently transferred toward N-glycans, O-glycans, and the arthro-series GSLs. Moreover, we showed that dbeta4GalNAcTA contributed to the synthesis of the LDN structure in vivo. The dbeta4GalNAcTA mRNA was highly expressed in the developmental and adult neuronal tissues. Thus, these results suggest that dbeta4GalNAcTA acts on the terminal GlcNAc residue of some glycans for the synthesis of LDN, and the LDN structure may play a role in the physiological or neuronal development of Drosophila.
authors.affiliation: Laboratory of Cell Biology, Department of Bioinformatics, Faculty of Engineering, Soka University, 1-236 Hachioji, Tokyo 192-8577, Japan.
authors.forename: Norihiko
authors.initials: N
authors.lastname: Sasaki
authors.forename: Hideki
authors.initials: H
authors.lastname: Yoshida
authors.forename: Takashi J
authors.initials: TJ
authors.lastname: Fuwa
authors.forename: Akiko
authors.initials: A
authors.lastname: Kinoshita-Toyoda
authors.forename: Hidenao
authors.initials: H
authors.lastname: Toyoda
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Hirabayashi
authors.forename: Hideki
authors.initials: H
authors.lastname: Ishida
authors.forename: Ryu
authors.initials: R
authors.lastname: Ueda
authors.forename: Shoko
authors.initials: S
authors.lastname: Nishihara
mesh_terms: D000818:Animals; D002240:Carbohydrate Sequence; D004187:Disaccharides / Q000096:biosynthesis* / Q000737:chemistry; D029721:Drosophila Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000502:physiology; D006023:Glycoproteins / Q000096:biosynthesis*; D006028:Glycosphingolipids / Q000096:biosynthesis*; D007785:Lactose / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000737:chemistry; D008969:Molecular Sequence Data; D017350:N-Acetylgalactosaminyltransferases / Q000737:chemistry / Q000502:physiology*
chemical_list: D004187:Disaccharides; D029721:Drosophila Proteins; D006023:Glycoproteins; D006028:Glycosphingolipids; C093701:N-acetylgalactosaminyl-1-4-N-acetylglucosamine; D017350:N-Acetylgalactosaminyltransferases; C023220:(N-acetylneuraminyl)-galactosylglucosylceramide N-acetylgalactosaminyltransferase; D007785:Lactose