title: Apical targeting of the formin Diaphanous in Drosophila tubular epithelia.
abstract: Apical secretion from epithelial tubes of the Drosophila embryo is mediated by apical F-actin cables generated by the formin-family protein Diaphanous (Dia). Apical localization and activity of Dia are at the core of restricting F-actin formation to the correct membrane domain. Here we identify the mechanisms that target Dia to the apical surface. PI(4,5)P2 levels at the apical membrane regulate Dia localization in both the MDCK cyst model and in Drosophila tubular epithelia. An N-terminal basic domain of Dia is crucial for apical localization, implying direct binding to PI(4,5)P2. Dia apical targeting also depends on binding to Rho1, which is critical for activation-induced conformational change, as well as physically anchoring Dia to the apical membrane. We demonstrate that binding to Rho1 facilitates interaction with PI(4,5)P2 at the plane of the membrane. Together these cues ensure efficient and distinct restriction of Dia to the apical membrane. DOI:http://dx.doi.org/10.7554/eLife.00666.001.
authors.affiliation: Department of Molecular Genetics , Weizmann Institute of Science , Rehovot , Israel.
authors.forename: Tal
authors.initials: T
authors.lastname: Rousso
authors.forename: Annette M
authors.initials: AM
authors.lastname: Shewan
authors.forename: Keith E
authors.initials: KE
authors.lastname: Mostov
authors.forename: Eyal D
authors.initials: ED
authors.lastname: Schejter
authors.forename: Ben-Zion
authors.initials: BZ
authors.lastname: Shilo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004285:Dogs; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000196:embryology*; D000080865:Formins; D049452:Green Fluorescent Proteins / Q000235:genetics; D061985:Madin Darby Canine Kidney Cells; D008969:Molecular Sequence Data; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid
chemical_list: D002352:Carrier Proteins; D029721:Drosophila Proteins; D000080865:Formins; D019269:Phosphatidylinositol 4,5-Diphosphate; C106890:diaphanous protein, Drosophila; D049452:Green Fluorescent Proteins
keywords: D. melanogaster; Diaphanous; PI(4,5)P2; Rho1; apical localization; formin; tubular epithelia