title: Myosin V, Rab11, and dRip11 direct apical secretion and cellular morphogenesis in developing Drosophila photoreceptors.
abstract: Sensory neuron terminal differentiation tasks apical secretory transport with delivery of abundant biosynthetic traffic to the growing sensory membrane. We recently showed Drosophila Rab11 is essential for rhodopsin transport in developing photoreceptors and asked here if myosin V and the Drosophila Rab11 interacting protein, dRip11, also participate in secretory transport. Reduction of either protein impaired rhodopsin transport, stunting rhabdomere growth and promoting accumulation of cytoplasmic rhodopsin. MyoV-reduced photoreceptors also developed ectopic rhabdomeres inappropriately located in basolateral membrane, indicating a role for MyoV in photoreceptor polarity. Binary yeast two hybrids and in vitro protein-protein interaction predict a ternary complex assembled by independent dRip11 and MyoV binding to Rab11. We propose this complex delivers morphogenic secretory traffic along polarized actin filaments of the subcortical terminal web to the exocytic plasma membrane target, the rhabdomere base. A protein trio conserved across eukaryotes thus mediates normal, in vivo sensory neuron morphogenesis.
authors.affiliation: Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Bingbing X
authors.initials: BX
authors.lastname: Li
authors.forename: Akiko K
authors.initials: AK
authors.lastname: Satoh
authors.forename: Donald F
authors.initials: DF
authors.lastname: Ready
mesh_terms: D000199:Actins / Q000378:metabolism; D048868:Adaptor Proteins, Signal Transducing / Q000502:physiology*; D000818:Animals; D030801:Animals, Genetically Modified; D002454:Cell Differentiation / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D029721:Drosophila Proteins / Q000378:metabolism / Q000502:physiology*; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics / Q000254:growth & development; D005089:Exocytosis / Q000502:physiology; D008565:Membrane Proteins / Q000502:physiology*; D024701:Myosin Type V / Q000502:physiology*; D010786:Photoreceptor Cells / Q000166:cytology* / Q000378:metabolism; D020691:rab GTP-Binding Proteins / Q000502:physiology*; D000099193:rab11 GTP-Binding Proteins
chemical_list: D000199:Actins; D048868:Adaptor Proteins, Signal Transducing; D029721:Drosophila Proteins; D008565:Membrane Proteins; D024701:Myosin Type V; D020691:rab GTP-Binding Proteins; D000099193:rab11 GTP-Binding Proteins; C520715:Rip11 protein, Drosophila