Multiple roles for TRPs in the taste system: not your typical TRPs.

The peripheral taste system is contained within taste buds located in the oral cavity. These taste buds are comprised of a heterogeneous group of taste receptor cells that use multiple signaling pathways to transduce chemical taste stimuli into an output signal that is sent to the brain. Salty and sour taste involve the detection of charged ions that directly interact with receptors to cause cell depolarization while bitter, sweet and umami taste stimuli activate G-protein coupled receptors and their second messenger pathways. The roles of TRP channels in these different signaling pathways are not well characterized and to date, only three TRP channels have been identified in taste receptor cells. This book chapter discusses the current understanding of how the three known TRP channels function in peripheral taste cell signaling: TRPM5, TRPV1, and the heterodimer PKD1L3/PKD2L1.