title: boudin is required for septate junction organisation in Drosophila and codes for a diffusible protein of the Ly6 superfamily.
abstract: The Ly6 superfamily, present in most metazoan genomes, codes for different cell-surface proteins and secreted ligands containing an extracellular motif called a Ly6 domain or three-finger domain. We report the identification of 36 novel genes coding for proteins of this family in Drosophila. One of these fly Ly6 proteins, coded by the gene boudin (bou), is essential for tracheal morphogenesis in the fly embryo and contributes to the maintenance of the paracellular barrier and the organisation of the septate junctions in this tissue. Bou, a glycosylphosphatidylinositol anchored membrane protein, is also required for septate junction organisation in epithelial tissues and in the chordotonal organ glial cells, but not in the central nervous system. Our study reveals interesting parallelisms between the Ly6 proteins of flies and vertebrates, such as the CD59 antigen. Similarly to this human protein, Bou travels from cell to cell associated with extracellular particles and, consistently, we show that it is required in a non-cell-autonomous fashion. Our work opens the way for future studies addressing the function of Ly6 proteins using Drosophila as a model system.
authors.affiliation: Université de Toulouse UPS, Centre de Biologie du Développement, CNRS UMR 5547, Bâtiment 4R3, 118 route de Narbonne, F-31062 Toulouse, France.
authors.forename: Assia
authors.initials: A
authors.lastname: Hijazi
authors.forename: Wilfried
authors.initials: W
authors.lastname: Masson
authors.forename: Benoit
authors.initials: B
authors.lastname: Augé
authors.forename: Lucas
authors.initials: L
authors.lastname: Waltzer
authors.forename: Marc
authors.initials: M
authors.lastname: Haenlin
authors.forename: Fernando
authors.initials: F
authors.lastname: Roch
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000950:Antigens, Ly / Q000235:genetics / Q000378:metabolism*; D001812:Blood-Brain Barrier / Q000196:embryology / Q000648:ultrastructure; D002462:Cell Membrane / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000033:anatomy & histology / Q000201:enzymology / Q000235:genetics; D006801:Humans; D007365:Intercellular Junctions / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009024:Morphogenesis / Q000502:physiology; D009417:Nerve Tissue / Q000033:anatomy & histology / Q000196:embryology; D016415:Sequence Alignment; D014132:Trachea / Q000033:anatomy & histology / Q000196:embryology*
chemical_list: D000950:Antigens, Ly; D029721:Drosophila Proteins; D008565:Membrane Proteins; C543574:bou protein, Drosophila; C504913:rtv protein, Drosophila