G-protein coupled receptor for cannabinoids (By similarity). Mediates many cannabinoid-induced effects in the central nervous system (CNS), as well as in peripheral tissue (By similarity)s. Regulates cellular respiration and energy production in response to cannabinoids (By similarity). Signaling typically involves reduction in cyclic AMP (By similarity). May be involved in the control of reproductive function (PubMed:16485273). Hemopressin, a peptide derived from hemoglobin subunit alpha (HBA1 and/or HBA2), acts as an antagonist peptide: hemopressin-binding efficiently blocks cannabinoid receptor CNR1 and subsequent signaling. Unexpectedly, in the mitochondria, the C-terminus is located in the mitochondrial intermembrane space, a compartment topologically considered as extracellular. In canonical seven-transmembrane G-protein coupled receptors, the C-terminus is cytosolic. Widely expressed, with high levels in the CNS and lower in testis, kidney, liver, ovary, muscle, heart, spleen and pituitary. In testis, poorly expressed during the winter stasis of the spermatogenesis rising during the breeding season and resumption period. Palmitoylation at Cys-407 is important for recruitment at both plasma membrane and lipid rafts and association with G protein alpha subunits. Belongs to the G-protein coupled receptor 1 family.