title: Real-time insights into regulated exocytosis.
abstract: Real-time imaging of regulated exocytosis in secreting organs can provide unprecedented temporal and spatial detail. Here, we highlight recent advances in 3D time-lapse imaging inDrosophilasalivary glands at single-granule resolution. Using fluorescently labeled proteins expressed in the fly, it is now possible to image the dynamics of vesicle biogenesis and the cytoskeletal factors involved in secretion. 3D imaging over time allows one to visualize and define the temporal sequence of events, including clearance of cortical actin, fusion pore formation, mixing of the vesicular and plasma membranes and recruitment of components of the cytoskeleton. We will also discuss the genetic tools available in the fly that allow one to interrogate the essential factors involved in secretory vesicle formation, cargo secretion and the ultimate integration of the vesicular and plasma membranes. We argue that the combination of high-resolution real-time imaging and powerful genetics provides a platform to investigate the role of any factor in regulated secretion.
authors.affiliation: Section on Biological Chemistry, NIDCR, National Institutes of Health, 30 Convent Drive, Bethesda, MD 20892, USA.
authors.forename: Duy T
authors.initials: DT
authors.lastname: Tran
authors.affiliation: Developmental Glycobiology Section, NIDCR, National Institutes of Health, 30 Convent Drive, Bethesda, MD 20892, USA Kelly.Tenhagen@nih.gov.
authors.forename: Kelly G
authors.identifier: 0000-0002-2057-8120
authors.initials: KG
authors.lastname: Ten Hagen
mesh_terms: D000818:Animals; D003599:Cytoskeleton / Q000378:metabolism; D004330:Drosophila / Q000502:physiology*; D005089:Exocytosis; D006801:Humans; D021621:Imaging, Three-Dimensional; D008561:Membrane Fusion; D008856:Microscopy, Fluorescence; D008967:Molecular Biology / Q000379:methods; D012469:Salivary Glands / Q000378:metabolism / Q000648:ultrastructure*; D022142:Secretory Vesicles / Q000648:ultrastructure*; D059008:Time-Lapse Imaging / Q000379:methods*
keywords: 4D imaging; Arp2; Arp3; Branched actin; Drosophila; Myosin; Regulated exocytosis; Salivary gland; Secretion; WASp