Mas-related G protein-coupled receptor A3 (MrgprA3)

Mas-related G protein-coupled receptor A3 (MrgprA3) is a member of the rhodopsin-like class A GPCR superfamily, chiefly expressed in a specialized subset of sensory neurons, notably in dorsal root ganglia (DRG). In mouse models, MrgprA3 acts as a molecular sensor for pruritic stimuli and is implicated in pathological itch and pain signaling. Its structure features atypical motifs compared to conventional class A GPCRs, such as lacking the canonical TM3-ECL2 disulfide bond and distinct residues in TM6, which are critical for its unique ligand interactions and signaling properties. MrgprA3's selective expression distinguishes a population of itch-sensitive neurons and represents a promising target in preclinical research for antipruritic and analgesic drug development.

Other names

MrgprA3Mas-related G protein-coupled receptor member A3Sensory neuron-specific GPCR A3

For agonists: activation of MrgprA3 leads to neuronal excitation and itch signaling via G protein-coupled mechanisms, usually Gq/11 protein-mediated signaling cascades. For antagonists: inhibition of receptor activity suppresses itch transmission and sensory neuron activation.