DRD2

G protein-coupled receptor for dopamine, a catecholamine neurotransmitter hormone that functions as the brain's 'reward chemical', driving motivation, reinforcement learning and pleasure. Dopamine binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G proteins) and modulates the activity of downstream effectors, such as adenylate cyclase. Dopamine receptors can be classified in two categories: (1) DRD2 (together with DRD3 and DRD4) is a D2-type receptor and is coupled to G(i)/G(o) G proteins, mediating inhibition of adenylate cyclase activity, while D1-type receptors (DRD1 and DRD5) are coupled to G(s) G proteins and promote activation of adenylate cyclase activity. In the central nervous system, DRD2 is mainly coupled to G(o)/GNAO1 (By similarity). D1- and D2-type dopamine receptors have antagonistic effects, particularly in the brain's striatum, where they govern voluntary movement and reward: D1-type receptors generally stimulate neural activity and promotes action, while D2-type receptors tend to inhibit neural activity and suppress movement (By similarity). DRD1 and DRD2 are the most abundant dopamine receptors in the central nervous system, especially in the basal ganglia and the prefrontal cortex. DRD2 receptor plays a key role in risky decision-making by modulating reward sensitivity and executive control; DRD2 activation in nucleus accumbens cells leading to increased risk-taking and impulsivity (By similarity). DRD2 can also couple with G(q) by forming a heteromer with the ghrelin receptor GHSR in neurons independently of ghrelin (By similarity). Following DRD2 activation by dopamine in lumbosacral defecation centers, GHSR acts as a coreceptor promoting DRD2 coupling to G(q) at the expense of G(i)/G(o), regulating defecation (By similarity). In addition to dopamine, also acts as a receptor for tryptophan-derived metabolites in intestinal epithelial cells: activation by tryptophan metabolites produced by the gut microbiota initiates a phospholipase-C-dependent signaling that promotes colonization resistance by pathogens by controlling actin cytoskeletal organization in the gut epithelium (By similarity). Positively regulates postnatal regression of retinal hyaloid vessels via suppression of VEGFR2/KDR activity, downstream of OPN5 (By similarity). Also acts as a receptor for D-lysergic (LSD) psychedelic drug..

Function from UniProtKB (P14416), read 2026-09-23. CC BY 4.0.