GPR18, GPR55 and GPR119 in GtoPdb v.2023.1

Abstract

GPR18, GPR55 and GPR119 (provisional nomenclature), although showing little structural similarity to CB₁ and CB₂ cannabinoid receptors, respond to endogenous agents analogous to the endogenous cannabinoid ligands, as well as some natural/synthetic cannabinoid receptor ligands [104]. Although there are multiple reports to indicate that GPR18, GPR55 and GPR119 can be activated in vitro by N-arachidonoylglycine, lysophosphatidylinositol and N-oleoylethanolamide, respectively, there is a lack of evidence for activation by these lipid messengers in vivo. As such, therefore, these receptors retain their orphan status.