title: Identification and expression analysis of zebrafish polypeptide α-N-acetylgalactosaminyltransferase Y-subfamily genes during embryonic development.
abstract: Mucin-type glycosylation is one of the most common posttranslational modifications of secretory and membrane proteins and has diverse physiological functions. The initial biosynthesis of mucin-type carbohydrates is catalyzed by UDP-GalNAc: polypeptide α-N-acetylgalactosaminyltransferases (GalNAc-Ts) encoded by GALNT genes. Among these, GalNAc-T8, -T9, -T17, and -T18 form a characteristic subfamily called "Y-subfamily" and have no or very low in vitro transferase activities when assayed with typical mucin peptides as acceptor substrates. Although the Y-subfamily isozymes have been reported to be possibly involved in various diseases, their in vivo functions have not been reported. Here, we isolated zebrafish Y-subfamily galnt genes, and determined their spatial and temporal expressions during the early development of zebrafish. Our study demonstrated that all the Y-subfamily isozymes were well conserved in zebrafish with GalNAc-T18 having two orthologs, galnt18a and galnt18b, and with the other three isozymes each having a corresponding ortholog, galnt8, galnt9, and galnt17. The galnt8 was expressed in the cephalic mesoderm and hatching gland during early developmental stages, and differently expressed in the head, somatic muscles, and liver in the later stages. The other three orthologs also exhibited the characteristic expression patterns, although their expressions were generally strong in the nervous systems. In addition to the expression in the brain, galnt17 and galnt18a were expressed in the somitic muscles, and galnt18a and galnt18b in the notochord. These expression patterns may contribute to the functional analysis of the Y-subfamily, whose physiological roles still remain to be elucidated.
authors.affiliation: Laboratory of Neuroglycobiology, Department of Molecular Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto 603-8555, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Nakayama
authors.affiliation: Laboratory of Neuroglycobiology, Department of Molecular Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto 603-8555, Japan.
authors.forename: Naosuke
authors.initials: N
authors.lastname: Nakamura
authors.affiliation: Laboratory of Neuroglycobiology, Department of Molecular Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto 603-8555, Japan.
authors.forename: Tamiko
authors.initials: T
authors.lastname: Kawai
authors.affiliation: Laboratory of Neuroglycobiology, Department of Molecular Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto 603-8555, Japan.
authors.forename: Eiichi
authors.initials: E
authors.lastname: Kaneda
authors.affiliation: Laboratory of Neuroglycobiology, Department of Molecular Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto 603-8555, Japan.
authors.forename: Yui
authors.initials: Y
authors.lastname: Takahashi
authors.affiliation: Department of Genetic Biochemistry, Kyoto University Graduate School of Pharmaceutical Sciences, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Miyake
authors.affiliation: Department of Genetic Biochemistry, Kyoto University Graduate School of Pharmaceutical Sciences, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Itoh
authors.affiliation: Laboratory of Neuroglycobiology, Department of Molecular Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto 603-8555, Japan. Electronic address: kurosaka@cc.kyoto-su.ac.jp.
authors.forename: Akira
authors.initials: A
authors.lastname: Kurosaka
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015870:Gene Expression; D007527:Isoenzymes / Q000235:genetics; D008969:Molecular Sequence Data; D017350:N-Acetylgalactosaminyltransferases / Q000235:genetics*; D016415:Sequence Alignment; D015027:Zebrafish / Q000196:embryology* / Q000235:genetics*; D000097763:Polypeptide N-acetylgalactosaminyltransferase
chemical_list: D007527:Isoenzymes; D017350:N-Acetylgalactosaminyltransferases; D000097763:Polypeptide N-acetylgalactosaminyltransferase
keywords: GalNAc-transferase; Neural development; Zebrafish embryonic development