Fig. 4From: Protease-activated receptors (PARs): mechanisms of action and potential therapeutic modulators in PAR-driven inflammatory diseasesG protein-coupled signaling induced by PAR activation. Depending on the tethered ligand, activated PAR couples with G protein α-subtypes. Gαq activates phospholipase Cβ (PLCβ), which mobilizes calcium. This further activates MAPKs (ERK1/2) and induces Ras signaling. Primarily, Gα12/12 and Gaq activate the Rho pathway. Gαi inhibits the activation of adenylyl cyclase, which leads to reduced production of cAMP. In contrast, the βγ-subunit functions as a negative regulator when bound to the α-subunit. After receptor activation, subunits separate, and the βγ-subunit interacts with other proteins, thereby activating or inhibiting signalingBack to article page