Fig. 3.
Proposed signaling pathway in type II receptor cells. AA inhibits the DRK channel and activates the TRPM5 channel. Intracellular K+ ions and influx of Na+ ions, through the TRPM5 channel, cause depolarization of the cells and firing of action potentials. AA, arachidonic acid; Ca2+, calcium ion; CALHM1, calcium homeostasis modulator 1; CD36, cluster of differentiation 36; DRK, delayed rectifying K+ channel; ER, endoplasmic reticulum; GPR120, G-protein coupled receptor 120; IP3, type 3 isoform of inositol 1,4,5-trisphosphate; K+, potassium ion; Na+, sodium ion; P2X, purinergic receptors; PL, phospholipids; PLC, phospholipase C; sPLA2, secreted phospholipase A2; TG, triglycerides.