title: Ral GTPase and the exocyst regulate autophagy in a tissue-specific manner.
abstract: Autophagy traffics cellular components to the lysosome for degradation. Ral GTPase and the exocyst have been implicated in the regulation of stress-induced autophagy, but it is unclear whether they are global regulators of this process. Here, we investigate Ral function in different cellular contexts in Drosophila and find that it is required for autophagy during developmentally regulated cell death in salivary glands, but does not affect starvation-induced autophagy in the fat body. Furthermore, knockdown of exocyst subunits has a similar effect, preventing autophagy in dying cells but not in cells of starved animals. Notch activity is elevated in dying salivary glands, this change in Notch signaling is influenced by Ral, and decreased Notch function influences autophagy. These data indicate that Ral and the exocyst regulate autophagy in a context-dependent manner, and that in dying salivary glands, Ral mediates autophagy, at least in part, by regulation of Notch.
authors.affiliation: Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, USA.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Tracy
authors.affiliation: Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, USA.
authors.forename: Panagiotis D
authors.initials: PD
authors.lastname: Velentzas
authors.affiliation: Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, USA eric.baehrecke@umassmed.edu.
authors.forename: Eric H
authors.initials: EH
authors.lastname: Baehrecke
mesh_terms: D000818:Animals; D001343:Autophagy; D016923:Cell Death; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000201:enzymology / Q000235:genetics* / Q000502:physiology*; D005216:Fat Body; D005786:Gene Expression Regulation; D051880:Receptors, Notch / Q000235:genetics / Q000378:metabolism; D012469:Salivary Glands / Q000166:cytology / Q000502:physiology; D013217:Starvation; D013312:Stress, Physiological; D020725:ral GTP-Binding Proteins / Q000235:genetics* / Q000378:metabolism*
chemical_list: D029721:Drosophila Proteins; C497759:N protein, Drosophila; D051880:Receptors, Notch; D020725:ral GTP-Binding Proteins
keywords: Drosophila; Notch; Ral GTPase; autophagy; cell death; exocyst