The function of PKD2L1 (polycystin 2 like 1, transient receptor potential cation channel, Ensembl gene identifier ENSG00000107593) is as follows. Homotetrameric, non-selective cation channel that is permeable to sodium, potassium, magnesium and calcium (PubMed:10517637, PubMed:11959145, PubMed:25820328, PubMed:27754867, PubMed:29425510, PubMed:30004384). Also forms functional heteromeric channels with PKD1, PKD1L1 and PKD1L3 (PubMed:23212381, PubMed:24336289). Pore-forming subunit of a heterotetrameric, non-selective cation channel, formed by PKD1L2 and PKD1L3, that is permeable to sodium, potassium, magnesium and calcium and which may act as a sour taste receptor in gustatory cells; however, its contribution to sour taste perception is unclear in vivo and may be indirect (PubMed:19812697, PubMed:23212381). The homomeric and heteromeric channels formed by PKD1L2 and PKD1L3 are activated by low pH and Ca(2+), but opens only when the extracellular pH rises again and after the removal of acid stimulus (PubMed:23212381). Pore-forming subunit of a calcium-permeant ion channel formed by PKD1L2 and PKD1L1 in primary cilia, where it controls cilium calcium concentration, without affecting cytoplasmic calcium concentration, and regulates sonic hedgehog/SHH signaling and GLI2 transcription (PubMed:24336289). The PKD1L1:PKD2L1 complex channel is mechanosensitive only at high pressures and is highly temperature sensitive (PubMed:24336289). Pore-forming subunit of a calcium-permeant ion channel formed by PKD1L2 and PKD1 that produces a transient increase in intracellular calcium concentration upon hypo-osmotic stimulation (200 mOsm) (By similarity). May play a role in the perception of carbonation taste (By similarity). May play a role in the sensory perception of water, via a mechanism that activates the channel in response to dilution of salivary bicarbonate and changes in salivary pH (By similarity). {ECO:0000250|UniProtKB:A2A259, ECO:0000269|PubMed:10517637, ECO:0000269|PubMed:11959145, ECO:0000269|PubMed:19812697, ECO:0000269|PubMed:23212381, ECO:0000269|PubMed:24336289, ECO:0000269|PubMed:25820328, ECO:0000269|PubMed:27754867, ECO:0000269|PubMed:29425510, ECO:0000269|PubMed:30004384}.