Human Dopamine Receptor D3 (DRD3) Protein

Background

DRD3 is a G protein-coupled receptor (GPCR) of the D2-like family that couples to Gi/o proteins, inhibiting adenylate cyclase activity and reducing intracellular cyclic AMP (cAMP) levels. It is primarily expressed in limbic regions of the brain, including the ventral striatum, nucleus accumbens, and olfactory tubercle, where it regulates emotional behavior, reward processing, and cognitive function. DRD3 is involved in motivation, reinforcement learning, and drug addiction, where its dysregulation contributes to compulsive behaviors and substance abuse disorders. In schizophrenia, altered DRD3 signaling is associated with cognitive and behavioral deficits, and it is a target for atypical antipsychotics. DRD3 also plays a role in Parkinson’s disease, where it regulates motor control and is upregulated in response to dopaminergic neuron loss, contributing to dyskinesia. Outside the brain, DRD3 is expressed in peripheral tissues, including the kidney and immune cells, where it influences renal function and immune responses. DRD3 is a promising therapeutic target for neuropsychiatric disorders, Parkinson’s disease, and addiction, with specific agonists and antagonists under development to modulate its function.