title: Functional PDF Signaling in the Drosophila Circadian Neural Circuit Is Gated by Ral A-Dependent Modulation.
abstract: The neuropeptide PDF promotes the normal sequencing of circadian behavioral rhythms in Drosophila, but its signaling mechanisms are not well understood. We report daily rhythmicity in responsiveness to PDF in critical pacemakers called small LNvs. There is a daily change in potency, as great as 10-fold higher, around dawn. The rhythm persists in constant darkness and does not require endogenous ligand (PDF) signaling or rhythmic receptor gene transcription. Furthermore, rhythmic responsiveness reflects the properties of the pacemaker cell type, not the receptor. Dopamine responsiveness also cycles, in phase with that of PDF, in the same pacemakers, but does not cycle in large LNv. The activity of RalA GTPase in s-LNv regulates PDF responsiveness and behavioral locomotor rhythms. Additionally, cell-autonomous PDF signaling reversed the circadian behavioral effects of lowered RalA activity. Thus, RalA activity confers high PDF responsiveness, providing a daily gate around the dawn hours to promote functional PDF signaling.
authors.affiliation: Dept. of Neuroscience, Washington University Medical School, 660 South Euclid Avenue, St. Louis, MO 63110 USA.
authors.forename: Markus
authors.initials: M
authors.lastname: Klose
authors.affiliation: Dept. of Neuroscience, Washington University Medical School, 660 South Euclid Avenue, St. Louis, MO 63110 USA.
authors.forename: Laura
authors.initials: L
authors.lastname: Duvall
authors.affiliation: Dept. of Neuroscience, Washington University Medical School, 660 South Euclid Avenue, St. Louis, MO 63110 USA.
authors.forename: Weihua
authors.initials: W
authors.lastname: Li
authors.affiliation: Dept. of Neuroscience, Washington University Medical School, 660 South Euclid Avenue, St. Louis, MO 63110 USA.
authors.forename: Xitong
authors.initials: X
authors.lastname: Liang
authors.affiliation: Dept. of Neuroscience, Washington University Medical School, 660 South Euclid Avenue, St. Louis, MO 63110 USA.
authors.forename: Chi
authors.initials: C
authors.lastname: Ren
authors.affiliation: Dept. of Anesthesiology, Washington University Medical School, 660 South Euclid Avenue, St. Louis, MO 63110 USA.
authors.forename: Joe Henry
authors.initials: JH
authors.lastname: Steinbach
authors.affiliation: Dept. of Neuroscience, Washington University Medical School, 660 South Euclid Avenue, St. Louis, MO 63110 USA.
authors.forename: Paul H
authors.initials: PH
authors.lastname: Taghert
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001522:Behavior, Animal / Q000502:physiology*; D001683:Biological Clocks / Q000502:physiology*; D001921:Brain / Q000378:metabolism*; D002940:Circadian Rhythm / Q000502:physiology*; D003624:Darkness; D029721:Drosophila Proteins / Q000235:genetics; D004331:Drosophila melanogaster; D009043:Motor Activity / Q000502:physiology*; D009474:Neurons / Q000378:metabolism*; D009479:Neuropeptides / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology
chemical_list: D029721:Drosophila Proteins; D009479:Neuropeptides
keywords: Drosophila; GPCR; PDF; RalA; circadian rhythms; dopamine