The biochemistry and physiology of the chemical senses and their relevance to food and nutrition.
1. Sweet and bitter taste transduction
2. Signal termination of taste: the role of signal termination-related kinases
3. Cross-talk between G Protein-coupled receptors and ERK.
4. Chemical pathways for aroma formation in food.
Sweet and bitter tastants stimulate the G protein-coupled taste receptors (GPCRs) T1R/T2Rs, which occur in the oral cavity as well as along the gastrointestinal tract. In addition, some sweet and bitter tastants rapidly permeate into isolated taste-bud cells in situ into taste-bud cells in vivo and into various epithelial cells ex vivo. Interestingly, the same tastants inhibited the phosphoryaltion of rhodopsin induced by GPRC kinases (GRK) and prortein kinase A (PKA) in vitro. These results propose that membrane-permenat tastants can potentially interfere with the desensitization of GPCRs by interacting with these signal termination-related kinases. Furthermore, they may have implications to the lingering aftertaste produced in humans after tasting such bitter tastants and artificial sweeteners.