title: Drosophila TRPA1 isoforms detect UV light via photochemical production of H2O2.
abstract: The transient receptor potential A1 (TRPA1) channel is an evolutionarily conserved detector of temperature and irritant chemicals. Here, we show that two specific isoforms of TRPA1 in Drosophila are H2O2 sensitive and that they can detect strong UV light via sensing light-induced production of H2O2. We found that ectopic expression of these H2O2-sensitive Drosophila TRPA1 (dTRPA1) isoforms conferred UV sensitivity to light-insensitive HEK293 cells and Drosophila neurons, whereas expressing the H2O2-insensitive isoform did not. Curiously, when expressed in one specific group of motor neurons in adult flies, the H2O2-sensitive dTRPA1 isoforms were as competent as the blue light-gated channelrhodopsin-2 in triggering motor output in response to light. We found that the corpus cardiacum (CC) cells, a group of neuroendocrine cells that produce the adipokinetic hormone (AKH) in the larval ring gland endogenously express these H2O2-sensitive dTRPA1 isoforms and that they are UV sensitive. Sensitivity of CC cells required dTRPA1 and H2O2 production but not conventional phototransduction molecules. Our results suggest that specific isoforms of dTRPA1 can sense UV light via photochemical production of H2O2. We speculate that UV sensitivity conferred by these isoforms in CC cells may allow young larvae to activate stress response--a function of CC cells--when they encounter strong UV, an aversive stimulus for young larvae.
authors.affiliation: Department of Neurobiology, Duke University Medical School, Durham, NC 27710;
authors.forename: Ananya R
authors.initials: AR
authors.lastname: Guntur
authors.affiliation: Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605;
authors.forename: Pengyu
authors.initials: P
authors.lastname: Gu
authors.affiliation: Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605;
authors.forename: Kendra
authors.initials: K
authors.lastname: Takle
authors.affiliation: Biological Graduate Program, Scripps Research Institute, La Jolla, CA 92037.
authors.forename: Jingyi
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605; yang@neuro.duke.edu Yang.Xiang@umassmed.edu.
authors.forename: Yang
authors.initials: Y
authors.lastname: Xiang
authors.affiliation: Department of Neurobiology, Duke University Medical School, Durham, NC 27710; yang@neuro.duke.edu Yang.Xiang@umassmed.edu.
authors.forename: Chung-Hui
authors.initials: CH
authors.lastname: Yang
mesh_terms: D000818:Animals; D004330:Drosophila; D029721:Drosophila Proteins / Q000502:physiology*; D057809:HEK293 Cells; D018841:HSP90 Heat-Shock Proteins / Q000502:physiology*; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D055668:Photochemical Processes; D020033:Protein Isoforms / Q000502:physiology*; D014466:Ultraviolet Rays
chemical_list: D029721:Drosophila Proteins; D018841:HSP90 Heat-Shock Proteins; D020033:Protein Isoforms; C581704:Trap1 protein, Drosophila; D006861:Hydrogen Peroxide
keywords: Drosophila; UV sensing; dTRPA1 isoforms; optogenetics; reactive oxygen species