Background: The endocannabinoid system functions through two well characterized receptor systems, the CB1 and CB2 receptors. Work by a number of groups in recent years has provided evidence that the system is more complicated and additional receptor types should exist to explain ligand activity in a number of physiological processes. Experimental approach: Cells transfected with the human cDNA for GPR55 were tested for their ability to bind and to mediate GTPgS binding by cannabinoid ligands. Using an antibody and peptide blocking approach, the nature of the Gprotein coupling was determined and further demonstrated by measuring activity of downstream signalling pathways. Key results: We demonstrate...
