Dopamine receptor D4 (DRD4) (DRD4)

The Dopamine receptor D4 (DRD4) is a G protein-coupled receptor (GPCR) belonging to the D2-like receptor family, primarily expressed in brain regions associated with cognitive and emotional functions, such as the prefrontal cortex and hippocampus (UniProt P21917). It functions by coupling to Gi/o proteins to inhibit adenylyl cyclase activity, thereby modulating synaptic plasticity and neurotransmitter release (PubChem CID 1815). A unique feature of the DRD4 gene is a 48-base pair variable number tandem repeat (VNTR) polymorphism in the third intracellular loop; the "D4.4" designation specifically refers to the common four-repeat allele (Wang et al., 2004). This receptor is a significant therapeutic target for atypical antipsychotics, most notably clozapine, which exhibits a significantly higher affinity for D4 than for D2 or D3 receptors (Oak et al., 2000). Dysregulation of DRD4 signaling is linked to several neuropsychiatric conditions, including attention-deficit hyperactivity disorder (ADHD), schizophrenia, and substance use disorders (Ptáček et al., 2011). Furthermore, the D4.4 variant and other polymorphisms are frequently studied in relation to personality traits like novelty seeking and individual differences in drug response (NIH Gene ID 1815).

Other names

D(4) dopamine receptorDRD4D4RDopamine D4 receptorD4.4 variantDopamine D4.4 receptor

Antagonist, Agonist, Partial agonist