A phytocannabinoid-sensitive phosphorylation switch converts endocannabinoids into alternative lipid GPCR activators

Endocannabinoids (eCBs) like anandamide and 2-arachidonoylglycerol are endogenous lipid ligands for CB ₁ and CB ₂ G protein-coupled receptors (GPCRs). Here, we show that phosphorylation of biologically important anandamide generates naturally occurring anandamide phosphate (AEAp), which switches GPCR ligand specificity to lysophosphatidic acid (LPA) receptors (LPARs) and the primate-specific bile acid sensory receptor MRGPRX4. The kinase responsible for anandamide phosphorylation was identified as diacylglycerol kinase (DGK) theta (DGKθ or DGKQ) using activity-guided brain fractionation, inhibitor profiling, recombinant reconstitution, and DGK isozyme screening. DGKQ showed noncanonical biphasic lipid kinetics and was inhibited by phytocannabinoids, most notably tetrahydrocannabinolic acid. Thus, eCBs are not only cannabinoid receptor ligands but also enzymatically adaptable lipid signals activating LPARs and MRGPRX4, thus linking metabolism of the distinct lipid LPA with Cannabis pharmacology.