Functions of Opsins in Drosophila Taste

Nicole Y Leung; Dhananjay P Thakur; Adishthi S Gurav; Sang Hoon Kim; Antonella Di Pizio; Masha Y Niv; Craig Montell

doi:10.1016/j.cub.2020.01.068

Functions of Opsins in Drosophila Taste

Curr Biol. 2020 Apr 20;30(8):1367-1379.e6. doi: 10.1016/j.cub.2020.01.068. Epub 2020 Apr 2.

Authors

Nicole Y Leung¹, Dhananjay P Thakur¹, Adishthi S Gurav¹, Sang Hoon Kim², Antonella Di Pizio³, Masha Y Niv⁴, Craig Montell⁵

Affiliations

¹ Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA; Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA.
² Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
³ Institute of Biochemistry, Food Science and Nutrition, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, 76100 Rehovot, Israel; The Fritz Haber Center for Molecular Dynamics, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel; Leibniz-Institute for Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany.
⁴ Institute of Biochemistry, Food Science and Nutrition, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, 76100 Rehovot, Israel; The Fritz Haber Center for Molecular Dynamics, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel.
⁵ Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA; Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA. Electronic address: cmontell@ucsb.edu.

Abstract

Rhodopsin is a light receptor comprised of an opsin protein and a light-sensitive retinal chromophore. Despite more than a century of scrutiny, there is no evidence that opsins function in chemosensation. Here, we demonstrate that three Drosophila opsins, Rh1, Rh4, and Rh7, are needed in gustatory receptor neurons to sense a plant-derived bitter compound, aristolochic acid (ARI). The gustatory requirements for these opsins are light-independent and do not require retinal. The opsins enabled flies to detect lower concentrations of aristolochic acid by initiating an amplification cascade that includes a G-protein, phospholipase Cβ, and the TRP channel, TRPA1. In contrast, responses to higher levels of the bitter compound were mediated through direct activation of TRPA1. Our study reveals roles for opsins in chemosensation and raise questions concerning the original roles for these classical G-protein-coupled receptors.

Keywords: Drosophila; GPCR; TRP channel; chromophore; gustatory; labellum; opsin; phospholipase C; retinal; rhodopsin.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

MeSH terms

Animals
Drosophila Proteins / genetics*
Drosophila Proteins / metabolism
Drosophila melanogaster / genetics
Drosophila melanogaster / physiology*
Female
Male
Opsins / genetics*
Opsins / metabolism
Random Allocation
Taste / physiology*
Taste Perception / physiology*

Substances

Drosophila Proteins
Opsins

Abstract

Publication types

MeSH terms

Substances

Grants and funding