Synonyms:PKD2L, PKDL, TRPP3 Background:Pore-forming subunit of a ciliary calcium channel that controls calcium concentration within primary cilia without affecting cytoplasmic calcium concentration. Forms a heterodimer with PKD1L1 in primary cilia and forms a calcium-permeant ciliary channel that regulates sonic hedgehog/SHH signaling and GLI2 transcription. May act as a sour taste receptor by forming a calcium channel with PKD1L3 in gustatory cells, however, its contribution to sour taste perception is unclear in vivo and may be indirect.