PKD2L1 (TRPP3) is a transient receptor potential cation channel that functions as both a homomeric and heteromeric ion channel permeable to sodium, potassium, magnesium, and calcium 1. The channel forms functional heteromers with PKD1L3, creating a unique 'off-response' channel that activates when extracellular pH rises following acid removal, though PKD2L1 can also exhibit this acid-sensing property independently 2. This heteromeric complex requires transmembrane domain interactions for proper cellular trafficking and localization to taste pores in circumvallate and foliate papillae 3. PKD2L1 trimerization is mediated by a novel C-terminal domain (K575-T622) that is critical for both channel assembly and function 1. The channel's activity is regulated by intracellular calcium and can be inhibited by capsaicin and its analogs 42. While PKD2L1 is expressed in acid-sensitive taste cells and has been proposed as a sour taste receptor, its direct role in sour taste perception remains unclear 5. Recent pharmacological screening has identified PKD2L1 as sharing molecular similarities with voltage-gated sodium channels, with inhibitors binding to lateral fenestration sites and stabilizing the inactivated state 6.