title: Guidance of subcellular tubulogenesis by actin under the control of a synaptotagmin-like protein and Moesin.
abstract: Apical membranes in many polarized epithelial cells show specialized morphological adaptations that fulfil distinct physiological functions. The air-transporting tubules of Drosophila tracheal terminal cells represent an extreme case of membrane specialization. Here we show that Bitesize (Btsz), a synaptotagmin-like protein family member, is needed for luminal membrane morphogenesis. Unlike in multicellular tubes and other epithelia, where it influences apical integrity by affecting adherens junctions, Btsz here acts at a distance from junctions. Localized at the luminal membrane through its tandem C2 domain, it recruits activated Moesin. Both proteins are needed for the integrity of the actin cytoskeleton at the luminal membrane, but not for other pools of F-actin in the cell, nor do actin-dependent processes at the outer membrane, such as filopodial activity or membrane growth depend on Btsz. Btsz and Moesin guide luminal membrane morphogenesis through organizing actin and allowing the incorporation of membrane containing the apical determinant Crumbs.
authors.affiliation: 1] Institute of Genetics, University of Cologne, Zülpicher Straße 47a, 50674 Cologne, Germany [2] The European Molecular Biology Laboratory, Meyerhofstr. 1, 69117 Heidelberg, Germany.
authors.forename: N
authors.initials: N
authors.lastname: JayaNandanan
authors.affiliation: The European Molecular Biology Laboratory, Meyerhofstr. 1, 69117 Heidelberg, Germany.
authors.forename: Renjith
authors.initials: R
authors.lastname: Mathew
authors.affiliation: 1] Institute of Genetics, University of Cologne, Zülpicher Straße 47a, 50674 Cologne, Germany [2] The European Molecular Biology Laboratory, Meyerhofstr. 1, 69117 Heidelberg, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Leptin
mesh_terms: D000199:Actins / Q000502:physiology*; D000818:Animals; D002478:Cells, Cultured; D003599:Cytoskeleton / Q000502:physiology*; D004330:Drosophila / Q000502:physiology*; D029721:Drosophila Proteins / Q000502:physiology*; D004847:Epithelial Cells / Q000166:cytology / Q000502:physiology; D007365:Intercellular Junctions / Q000502:physiology; D008565:Membrane Proteins / Q000502:physiology*; D009024:Morphogenesis / Q000502:physiology; D014132:Trachea / Q000166:cytology / Q000502:physiology
chemical_list: D000199:Actins; D029721:Drosophila Proteins; D008565:Membrane Proteins; C479933:btsz protein, Drosophila; C099886:moesin, Drosophila