Transduction of bitter and sweet taste by gustducin

Nature. 1996 Jun 27;381(6585):796-800. doi: 10.1038/381796a0.


Several lines of evidence suggest that both sweet and bitter tastes are transduced via receptors coupled to heterotrimeric guanine-nucleotide-binding proteins (G proteins). Gustducin is a taste receptor cell (TRC)-specific G protein that is closely related to the transducins. Gustducin and rod transducin, which is also expressed in TRCs, have been proposed to couple bitter-responsive receptors to TRC-specific phosphodiesterases to regulate intracellular cyclic nucleotides. Here we investigate gustducin's role in taste transduction by generating and characterizing mice deficient in the gustducin alpha-subunit (alpha-gustducin). As predicted, the mutant mice showed reduced behavioural and electrophysiological responses to bitter compounds, whereas they were indistinguishable from wild-type controls in their responses to salty and sour stimuli. Unexpectedly, mutant mice also exhibited reduced behavioural and electrophysiological responses to sweet compounds. Our results suggest that gustducin is a principal mediator of both bitter and sweet signal transduction.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cloning, Molecular
  • Facial Nerve / physiology
  • Female
  • Guanidines
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mutagenesis
  • Quaternary Ammonium Compounds
  • Quinine
  • Signal Transduction*
  • Sodium Chloride
  • Sucrose
  • Sweetening Agents
  • Taste / genetics
  • Taste / physiology*
  • Taste Buds / physiology
  • Transducin / deficiency
  • Transducin / genetics
  • Transducin / physiology*


  • Guanidines
  • Quaternary Ammonium Compounds
  • SC 45647
  • Sweetening Agents
  • gustducin
  • Sodium Chloride
  • denatonium benzoate
  • Sucrose
  • Quinine
  • Transducin