Family

Dopamine D2 receptor (IPR001922)

Short name: Dopamine_D2_rcpt

Family relationships

Description

Dopamine receptors are members of the rhodopsin-like G-protein coupled receptor family and are prominent in the vertebrate central nervous system (CNS). Dysfunction of dopaminergic neurotransmission in the CNS has been implicated in a variety of neuropsychiatric disorders [PMID: 15148138], including social phobia [PMID: 10698826], Tourette's syndrome [PMID: 16613557], Parkinson's disease [PMID: 17017512], schizophrenia [PMID: 16613557], neuroleptic malignant syndrome [PMID: 12555236], attention-deficit hyperactivity disorder (ADHD) [PMID: 16961425] and drug and alcohol dependence [PMID: 16613557, PMID: 11920678]. As a result, dopamine receptors are common drug targets; antipsychotics are often dopamine receptor antagonists while psychostimulants are typically indirect agonists of dopamine receptors [PMID: 9633679, PMID: 16433053, PMID: 14060771, PMID: 1060115].

There are at least five different known subtypes of dopamine receptors designated D1, D2, D3, D4 and D5 [PMID: 12836695]. They are distinguished by their G-protein coupling, ligand specificity, anatomical distribution and physiological effects. Dopamine receptors are divided into two further subfamilies. The D1-like family consists of D1 and D5 receptors, which couple to Gs and mediate excitatory neurotransmission. The D2-like family, meanwhile, consists of D2, D3 and D4 receptors, which couple to Gi/Go and mediate inhibitory neurotransmission. Although dopamine receptors are widely distributed in the brain, they are found in different locations that have different receptor type densities, presumably reflecting different functional roles [PMID: 9457173]. D1 and D2 receptor subtypes are found at 10-100 times the levels of the D3, D4, D5 subtypes [PMID: 16458973].

This entry represents the dopamine D2 receptors. They have a similar pharmacological profile to D3 and D4 receptors. The D2 receptor is present in high levels in the principal dopamine projection areas (including the caudate-putamen, nucleus accumbens and olfactory tubercle); they are found in cell bodies of dopaminergic neurons in the substantia nigra and ventral tegmental area, and in the periphery they are found in the pituitary, heart and blood vessels. In humans, the pulmonary artery expresses D1, D2, D4, and D5 and receptor subtypes, which may account for vasodilatory effects of dopamine in the blood [PMID: 16968475].

Dopamine D2 receptors have been shown to be important in the reward effects of morphine [PMID: 15671878]. D2 receptor knockout mice have been shown exhibit abnormal synaptic plasticity [PMID: 9169514] and to display reduced levels of aggression [PMID: 11303741].

GO terms

Biological Process

GO:0007195 adenylate cyclase-inhibiting dopamine receptor signaling pathway

Molecular Function

GO:0004952 dopamine neurotransmitter receptor activity

Cellular Component

GO:0016021 integral component of membrane

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PRINTS