There is also evidence that sweet taste reception may be not limited only to the T1R-mediated mechanisms. Glucose transporter 4 (GLUT4), sodium-glucose co-transporter (SGLT1), and ATP-gated K+ (KATP) metabolic sensors are present in T1R3-expressing taste cells and may serve as mediators of the T1R-independent sweet taste of sugars in mice.[44] In addition, some sweet-tasting compounds can penetrate the TRC membrane and act on intracellular targets,[45] which in this case could function as intracellular receptors of such compounds.
