title: Mucin-type core 1 glycans regulate the localization of neuromuscular junctions and establishment of muscle cell architecture in Drosophila.
abstract: T antigen (Galβ1-3GalNAcα1-Ser/Thr), a core 1 mucin-type O-glycan structure, is synthesized by Drosophila core 1 β1,3-galactosyltrasferase 1 (dC1GalT1) and is expressed in various tissues. We previously reported that dC1GalT1 synthesizes T antigen expressed in hemocytes, lymph glands, and the central nervous system (CNS) and that dC1GalT1 mutant larvae display decreased numbers of circulating hemocytes and excessive differentiation of hematopoietic stem cells in lymph glands. dC1GalT1 mutant larvae have also been shown to have morphological defects in the CNS. However, the functions of T antigen in other tissues remain largely unknown. In this study, we found that glycans contributed to the localization of neuromuscular junction (NMJ) boutons. In dC1GalT1 mutant larvae, NMJs were ectopically formed in the cleft between muscles 6 and 7 and connected with these two muscles. dC1GalT1 synthesized T antigen, which was expressed at NMJs. In addition, we determined the function of mucin-type O-glycans in muscle cells. In dC1GalT1 mutant muscles, myofibers and basement membranes were disorganized. Moreover, ultrastructural defects in NMJs and accumulation of large endosome-like structures within both NMJ boutons and muscle cells were observed in dC1GalT1 mutants. Taken together, these results demonstrated that mucin-type O-glycans synthesized by dC1GalT1 were involved in the localization of NMJ boutons, synaptogenesis of NMJs, establishment of muscle cell architecture, and endocytosis.
authors.affiliation: Laboratory of Cell Biology, Department of Bioinformatics, Graduate School of Engineering, Soka University, 1-236 Tangi-machi, Hachioji-shi, Tokyo 192-8577, Japan.
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Itoh
authors.affiliation: Department of Anatomy, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka-shi, Tokyo 181-8611, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Akimoto
authors.affiliation: Laboratory of Cell Biology, Department of Bioinformatics, Graduate School of Engineering, Soka University, 1-236 Tangi-machi, Hachioji-shi, Tokyo 192-8577, Japan.
authors.forename: Takashi J
authors.initials: TJ
authors.lastname: Fuwa
authors.affiliation: Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba-shi, Ibaraki 305-8566, Japan.
authors.forename: Chikara
authors.initials: C
authors.lastname: Sato
authors.affiliation: Department of Biosciences, Faculty of science and engineering, Teikyo University, 1-1 Toyosatodai, Utsunomiya-shi, Tochigi 320-0003, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Komatsu
authors.affiliation: Laboratory of Cell Biology, Department of Bioinformatics, Graduate School of Engineering, Soka University, 1-236 Tangi-machi, Hachioji-shi, Tokyo 192-8577, Japan. Electronic address: shoko@soka.ac.jp.
authors.forename: Shoko
authors.initials: S
authors.lastname: Nishihara
mesh_terms: D000818:Animals; D004330:Drosophila / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D009077:Mucins / Q000378:metabolism*; D009132:Muscles / Q000378:metabolism*; D009469:Neuromuscular Junction / Q000378:metabolism*; D011134:Polysaccharides / Q000378:metabolism*
chemical_list: D009077:Mucins; D011134:Polysaccharides
keywords: Basement membrane; Drosophila core 1 β1,3-galactosyltransferase 1; Mucin-type O-glycan; Muscle; Neuromuscular junction; T antigen