Cytosolic calcium activates the nonselective cation channel, transient receptor potential cation channel subfamily M member (
TRPM5), causing plasma membrane depolarization, which activates voltage-gated sodium ([Na.sup.+]) channels, resulting in action potential propagation that ultimately causes ATP release through calcium homeostasis modulator 1 (CALHM1), a large pore channel [9, 24-26].
Phospholipase C [beta]2 (PLC[beta]2) is subsequently stimulated, leading to release of intracellular [Ca.sup.2+] and activation of the transient receptor potential channel M5 (
TRPM5).
Arachidonic acid can function as a signaling modulator by activating the
TRPM5 cation channel in taste receptor cells.
Activation of
TRPM5 Underlies Thermal Sensitivity of Sweet Taste, 438
Sclafani, "Impact of T1r3 and
Trpm5 on carbohydrate preference and acceptance in C57BL/6 mice," Chemical Senses, vol.
Shigeto et al.: GLP-1 stimulates insulin secretion by PKC-dependent TRPM4 and
TRPM5 activation.
Zhang notes that all three tastes require a protein called
Trpm5, which is impaired by cold temperatures.
G-protein [alpha]-Gustducin and
TrpM5 Channel in Solitary Chemosensory Cells are Necessary for the Trigeminal Respiratory Depression Response Elicited by the Bitter Compound Denatonium Benzoate, Marco Tizzano, University of Colorado, Denver, A.
The researchers have also found a second pathway, the peripheral
Trpm5 protein pathway -that helps animals sense a bitter taste.
According to the study, the reaction of
TRPM5 in our taste buds is much more intense when the temperature of food or fluid is increased, sending a stronger electrical signal to the brain and resulting in an enhanced taste.