Coupling of Airway Smooth Muscle Bitter Taste Receptors to Intracellular Signaling and Relaxation Is via G_αi1,2,3.

ABSTRACT: Bitter taste receptors (TAS2Rs) are expressed on human airway smooth muscle (HASM) and evoke marked relaxation. Agonist interaction with TAS2Rs activates phospholipase C and increases compartmentalized intracellular Ca²⁺ ([Ca²⁺]_i) via inositol 1,4,5 triphosphate. In taste cells, the G protein gustducin couples TAS2R to phospholipase C; however, we find very low levels of G_αgust mRNA or protein in HASM. We hypothesized that another G protein in HASM transmits TAS2R function. TAS2R signaling to [Ca²⁺]_i, extracellular signal-regulated kinase (ERK) 1/2, and physiologic relaxation was sensitive to pertussis toxin, confirming a role for a member of the G_i family. α subunit expression in HASM was G_αi2 > G

SUBMITTER: Kim D 

PROVIDER: S-EPMC5516295 | biostudies-literature | 2017 Jun

REPOSITORIES: biostudies-literature