Animals use taste to sample and ingest essential nutrients for survival. Free fatty acids (FAs) are energy-rich nutrients that contribute to various cellular functions. Recent evidence suggests FAs are detected through the gustatory system to promote feeding. In Drosophila, phospholipase C (PLC) signaling in sweet-sensing cells is required for FA detection but other signaling molecules are unknown. Here, we show Gr64e is required for the behavioral and electrophysiological responses to FAs. GR64e and TRPA1 are interchangeable when they act downstream of PLC: TRPA1 can substitute for GR64e in FA but not glycerol sensing, and GR64e can substitute for TRPA1 in aristolochic acid but not N-methylmaleimide sensing. In contrast to its role in FA sensing, GR64e functions as a ligand-gated ion channel for glycerol detection. Our results identify a novel FA transduction molecule and reveal that Drosophila Grs can act via distinct molecular mechanisms depending on context.
Bibliographical noteFunding Information:
This work was supported by a National Research Foundation of Korea (NRF) Grant funded by the Korean Government (MSIP) (NRF-2016R1A5A2008630 and NRF- 2014R1A2A1A11050045). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. We thank the Bloomington Stock Center, National Institute of Genetics Fly Stock Center, and Drs. H. Amrein, A. Dahanukar, P. Garrity, B. Dickson and C. Montell for fly stocks. We thank Miss Y. Yoo for helping generate mutant flies.
All Science Journal Classification (ASJC) codes
- Ecology, Evolution, Behavior and Systematics
- Molecular Biology
- Cancer Research