Dopamine receptor responsible for neuronal signaling in the mesolimbic system of the brain, an area of the brain that regulates emotion and complex behavior. Activated by dopamine, but also by epinephrine and norepinephrine, and by numerous synthetic agonists and drugs. Agonist binding triggers signaling via G proteins that inhibit adenylyl cyclase (By similarity). Modulates the circadian rhythm of contrast sensitivity by regulating the rhythmic expression of NPAS2 in the retinal ganglion cells (PubMed:24048828). Forms homo- and heterooligomers with DRD2. D4.7 allele exhibits higher affinity for homodimers compared to DRD2 heterodimers, while alleles D42. and 4.4 have similar affinities for both. The interaction with DRD2 may modulate agonist-induced downstream signaling (By similarity). Interacts with CLIC6 (By similarity). Interacts with GPRASP1. May interact with ADORA2A. Interacts with KLHL12 (By similarity). Detected in olfactory bulb, hypothalamus, olfactory tubercle, brainstem and striatum. Palmitoylated. Palmitoylation of the C-terminal Cys is important for normal expression at the cell membrane. Mice show a significant reduction in daytime contrast sensitivity. Belongs to the G-protein coupled receptor 1 family. In contrast to human protein, does not interact with KLHL12 and is not ubiquitinated by the BCR(KLHL12) complex.