title: Two pathways for importing GDP-fucose into the endoplasmic reticulum lumen function redundantly in the O-fucosylation of Notch in Drosophila.
abstract: Notch is a transmembrane receptor that shares homology with proteins containing epidermal growth factor-like repeats and mediates the cell-cell interactions necessary for many cell fate decisions. In Drosophila, O-fucosyltransferase 1 catalyzes the O-fucosylation of these epidermal growth factor-like repeats. This O-fucose elongates, resulting in an O-linked tetrasaccharide that regulates the signaling activities of Notch. Fucosyltransferases utilize GDP-fucose, which is synthesized in the cytosol, but fucosylation occurs in the lumen of the endoplasmic reticulum (ER) and Golgi. Therefore, GDP-fucose uptake into the ER and Golgi is essential for fucosylation. However, although GDP-fucose biosynthesis is well understood, the mechanisms and intracellular routes of GDP-fucose transportation remain unclear. Our previous study on the Drosophila Golgi GDP-fucose transporter (Gfr), which specifically localizes to the Golgi, suggested that another GDP-fucose transporter(s) exists in Drosophila. Here, we identified Efr (ER GDP-fucose transporter), a GDP-fucose transporter that localizes specifically to the ER. Efr is a multifunctional nucleotide sugar transporter involved in the biosynthesis of heparan sulfate-glycosaminoglycan chains and the O-fucosylation of Notch. Comparison of the fucosylation defects in the N-glycans in Gfr and Efr mutants revealed that Gfr and Efr made distinct contributions to this modification; Gfr but not Efr was crucial for the fucosylation of N-glycans. We also found that Gfr and Efr function redundantly in the O-fucosylation of Notch, although they had different localizations and nucleotide sugar transportation specificities. These results indicate that two pathways for the nucleotide sugar supply, involving two nucleotide sugar transporters with distinct characteristics and distributions, contribute to the O-fucosylation of Notch.
authors: From the Genome and Drug Research Center, Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510.
authors: Hiroyuki O
authors: HO
authors: Ishikawa
authors: the Department of Biological Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510.
authors: Tomonori
authors: T
authors: Ayukawa
authors: From the Genome and Drug Research Center, Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510.
authors: Minoru
authors: M
authors: Nakayama
authors: the Department of Biological Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510.
authors: Shunsuke
authors: S
authors: Higashi
authors: the Department of Bioinformatics, Soka University, 1-236 Tangi-cho, Hachioji, Tokyo 192-8577, and.
authors: Shin
authors: S
authors: Kamiyama
authors: the Department of Bioinformatics, Soka University, 1-236 Tangi-cho, Hachioji, Tokyo 192-8577, and.
authors: Shoko
authors: S
authors: Nishihara
authors: the Department of Biochemical Cell Research, Tokyo Metropolitan Institute of Medical Science, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo 113-8613, Japan.
authors: Kazuhisa
authors: K
authors: Aoki
authors: the Department of Biochemical Cell Research, Tokyo Metropolitan Institute of Medical Science, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo 113-8613, Japan.
authors: Nobuhiro
authors: N
authors: Ishida
authors: the Department of Biochemical Cell Research, Tokyo Metropolitan Institute of Medical Science, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo 113-8613, Japan.
authors: Yutaka
authors: Y
authors: Sanai
authors: From the Genome and Drug Research Center, Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510; the Department of Biological Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510. Electronic address: matsuno@rs.noda.tus.ac.jp.
authors: Kenji
authors: K
authors: Matsuno
mesh_terms: D000818:Animals; D001692:Biological Transport; D015153:Blotting, Western; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006025:Glycosaminoglycans / Q000096:biosynthesis; D006031:Glycosylation; D006056:Golgi Apparatus / Q000378:metabolism; D006154:Guanosine Diphosphate Fucose / Q000378:metabolism*; D007150:Immunohistochemistry; D009004:Monosaccharide Transport Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D033704:Nucleotide Transport Proteins / Q000235:genetics / Q000378:metabolism; D011134:Polysaccharides / Q000378:metabolism; D051880:Receptors, Notch / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D029721:Drosophila Proteins; C547522:Efr protein, Drosophila; D006025:Glycosaminoglycans; D009004:Monosaccharide Transport Proteins; C497759:N protein, Drosophila; D033704:Nucleotide Transport Proteins; D011134:Polysaccharides; D051880:Receptors, Notch; C494581:nac protein, Drosophila; D006154:Guanosine Diphosphate Fucose