9.A.14.2.6
Cannabinoid receptor 2, CNR2. The endocannabinoid system is widely present in the retina where it can modulate neurotransmitter release and ion channel activity (Bouchard et al. 2016). Endogenous endocannabinoids such as anandamide and 2-arachidonoyl glycerol (2AG) bind to the receptor and influence many processes including feeding, learning, memory, pain, emotions, sleep and dreams (Murillo-Rodriguez et al. 2017).  It plays a vital role in regulation of immune response, inflammation, pain, and other metabolic processes. Its 3-d structure has been studied by NMR (Yeliseev and Gawrisch 2017). EPR studies revealed that higher mobility was observed in the center of internal loop 3,  and a structural change occurs between agonist vs. inverse agonist-bound CB2 in the extracellular tip of transmembrane helix 6 (Yeliseev et al. 2021).