title: Drosophila big brain does not act as a water channel, but mediates cell adhesion.
abstract: The neurogenic gene Drosophila big brain (bib) has a high sequence homology to aquaporin-4. However, its cellular functions in Drosophila neurogenesis have remained elusive. Here we investigated cell adhesion, and the ion and water permeability of Bib. The adhesive function was examined by a cell aggregation assay using L cells. Bib-transfected L cells formed aggregated clusters, while control-L cells remained as a single cell suspension. Ion permeation was not confirmed in L cells stably expressing Bib. When expressed in COS7 cells, Bib exhibited limited water permeability. This newly found cell adhesive function of Bib may be important for Drosophila neurogenesis.
authors.affiliation: Department of Pharmacology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Kimiko
authors.initials: K
authors.lastname: Tatsumi
authors.forename: Shoji
authors.initials: S
authors.lastname: Tsuji
authors.forename: Hideki
authors.initials: H
authors.lastname: Miwa
authors.forename: Toshinori
authors.initials: T
authors.lastname: Morisaku
authors.forename: Mutsuo
authors.initials: M
authors.lastname: Nuriya
authors.forename: Minako
authors.initials: M
authors.lastname: Orihara
authors.forename: Kazunari
authors.initials: K
authors.lastname: Kaneko
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Okano
authors.forename: Masato
authors.initials: M
authors.lastname: Yasui
mesh_terms: D000818:Animals; D051401:Aquaporin 4 / Q000235:genetics / Q000378:metabolism; D020346:Aquaporins / Q000235:genetics / Q000502:physiology*; D019921:Biotinylation; D019556:COS Cells; D002448:Cell Adhesion / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D002522:Chlorocebus aethiops; D029721:Drosophila Proteins / Q000235:genetics / Q000502:physiology*; D015870:Gene Expression; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007739:L Cells; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology*; D051379:Mice; D018408:Patch-Clamp Techniques; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014162:Transfection
chemical_list: C496030:AQP4 protein, human; D051401:Aquaporin 4; D020346:Aquaporins; D029721:Drosophila Proteins; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; C070621:bib protein, Drosophila; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins