An Odorant-Binding Protein Required for Suppression of Sweet Taste by Bitter Chemicals

作者：Jeong Yong Taek; Shim Jaewon; Oh So Ra; Yoon Hong In; Kim Chul Hoon; Moon Seok Jun^*; Montell Craig

来源：Neuron, 2013, 79(4): 725-737.

DOI：10.1016/j.neuron.2013.06.025

Animals often must decide whether or not to consume a diet that contains competing attractive and aversive compounds. Here, using the fruit fly, Drosophila melanogaster, we describe a mechanism that influences this decision. Addition of bitter compounds to sucrose suppressed feeding behavior, and this inhibition depended on an odorant-binding protein (OBP) termed OBP49a. In wild-type flies, bitter compounds suppressed sucrose-induced action potentials, and the inhibition was impaired in Obp49a mutants. However, loss of OBP49a did not affect action potentials in sugar- or bitter-activated gustatory receptor neurons (GRNs) when the GRNs were presented with just one type of tastant. OBP49a was expressed in accessory cells and acted non-cell-autonomously to attenuate nerve firings in sugar-activated GRNs when bitter compounds were combined with sucrose. These findings demonstrate an unexpected role for an OBP in taste and identify a molecular player involved in the integration of opposing attractive and aversive gustatory inputs.

• 出版日期2013-8-21