Dopamine receptor whose activity is mediated by G proteins which inhibit adenylyl cyclase (PubMed:1321233). Positively regulates postnatal regression of retinal hyaloid vessels via suppression of VEGFR2/KDR activity, downstream of OPN5 (By similarity). Forms homo- and heterooligomers with DRD4 (By similarity). The interaction with DRD4 may modulate agonist-induced downstream signaling (By similarity). Interacts with CADPS and CADPS2 (By similarity). Interacts with GPRASP1, PPP1R9B and CLIC6 (PubMed:10391935, PubMed:14499480, PubMed:16049099). Interacts with ARRB2 (PubMed:19332542). Interacts with HTR2A (By similarity). Interacts with DRD1 (By similarity). Interacts with KCNA2 (By similarity). Expressed in the anterior lobe of the pituitary gland (PubMed:2531656). Expressed ventral tegmental area of the midbrain and the pars compacta of the substantia nigra (PubMed:2531656). Expressed seven times more than isoform short in the caudate nucleus (PubMed:2137198). Expressed in the anterior lobe of the pituitary gland (PubMed:2531656). Expressed in the caudate nucleus (PubMed:2137198). Not expressed in the wider brain (PubMed:2531656). Palmitoylated. Palmitoylation which is required for proper localization to the plasma membrane and stability of the receptor could be carried on by ZDHHC4, ZDHHC3 and ZDHHC8. Belongs to the G-protein coupled receptor 1 family.