UC San Diego

There are five basic taste modalities in mammals: bitter, sweet, sour, salty, and Umami (taste of MSG and L-amino acids). Receptors for bitter, sweet, and Umami were previously discovered. Identities of receptors for salty and sour taste modalities remained elusive. In this dissertation, I will present: 1) development of a novel bioinformatics screen to discover candidate receptors; 2) discovery of a novel gene, PKD2L1, in taste receptor cells; 3) evidence demonstrating PKD2L1-expressing taste receptor cells mediate sour taste in mice; 4) evidence that PKD2L1-expressing cells in the spinal cord also mediate acid/pH sensing; and 5) evidence that representation of sour taste in the mammalian taste bud is independent of bitter, sweet, Umami, and salt