Molecular mechanisms underlying the reception and transmission of sour taste information

Abstract

Taste enables organisms to determine the properties of ingested substances by conveying information regarding the five basic taste modalities: sweet, salty, sour, bitter, and umami. The sweet, salty, and umami taste modalities convey the carbohydrate, electrolyte, and glutamate content of food, indicating its desirability and stimulating appetitive responses. The sour and bitter modalities convey the acidity of food and the presence of potential toxins, respectively, stimulating aversive responses to such tastes. In recent years, the receptors mediating sweet, bitter, and umami tastes have been identified as members of the T1R and T2R G-protein-coupled receptor families; however, the molecular mechanisms underlying sour taste detection have yet to be clearly elucidated. This review covers the molecular mechanisms proposed to mediate the detection and transmission of sour stimuli, focusing on polycystic kidney disease 1-like 3 (Pkd1l3), Pkd2l1, and carbonic anhydrase 4 (Car4).

The sensory ecology of primate food perception, revisited

“…[179][180][181][182] The molecular mechanisms involved in the other taste modalities (salt, sour, fat), are relatively less well understood, but several candidate genes have been proposed in the last 10 years. 175,183,184 Further, contrary to popular belief of a "taste map" of the tongue (e.g., that parts of the tongue specialize in different taste modalities), all major taste modalities are expressed in all regions of the tongue. 176 The last 20 years has also seen renewed interest in physiologically evaluating taste sensitivities to different compounds across primate species, particularly in relation to dietary strategy and body size.…”

“…Consequently, research in both human nutrition and primate sensory ecology have focused on exploring the relationships between this genetic variation and individual and species‐specific taste sensitivities and food preferences 179–182 . The molecular mechanisms involved in the other taste modalities (salt, sour, fat), are relatively less well understood, but several candidate genes have been proposed in the last 10 years 175,183,184 . Further, contrary to popular belief of a “taste map” of the tongue (e.g., that parts of the tongue specialize in different taste modalities), all major taste modalities are expressed in all regions of the tongue 176 …”

Identification of cholinergic chemosensory cells in mouse tracheal and laryngeal glandular ducts

“…This is well known for pancreatic duct cells that have high CA IV levels in their cytoplasm to catalyze hydration of CO 2 , and secrete a bicarbonate-rich isotonic fluid [55,56]. In addition, CA IV was recently identified as a mechanism for the detection of sour stimuli in the taste bud that is operating independently of TRPM5-signaling [57,58]. The physiological significance of CO 2 detection in the taste bud might be the recognition of CO 2 -producing sources [59,60] and to mediate protective taste behaviors such as avoidance of fermented food.…”

Receptomics, design of a microfluidic receptor screening technology

“…There is one more controversial taste sensation, the taste of fat or fatty acids [18,19], but evidence is not conclusive. Salty and sour tastes are sensed by sodium ion channels and proton ion channels respectively [20][21][22]. The sweet and umami tastes are recognized by the class C receptors that form dimers of two GPCRs [23].…”