Dopamine receptor D2

2019-01-05T02:05:54Z

2601:640:8301:7130:3456:1163:FBAF:1A13: /* Oligomerization of D2R */

{{DISPLAYTITLE:Dopamine receptor D2}}
{{Infobox_gene}}
'''Dopamine receptor D2''', also known as '''D2R''', is a [[protein]] that, in humans, is encoded by the ''DRD2'' [[gene]]. After work from Paul Greengard's lab had suggested that dopamine receptors were the site of action of antipsychotic drugs, several groups (including those of Solomon Snyder and Philip Seeman) used a radiolabeled antipsychotic drug to identify what is now known as the [[dopamine]] D2 receptor.<ref>{{cite journal | vauthors = Madras BK | title = History of the discovery of the antipsychotic dopamine D2 receptor: a basis for the dopamine hypothesis of schizophrenia | journal = Journal of the History of the Neurosciences | volume = 22 | issue = 1 | pages = 62–78 | date = 2013 | pmid = 23323533 | doi = 10.1080/0964704X.2012.678199 }}</ref> The dopamine D2 receptor is the main [[receptor (biochemistry)|receptor]] for most [[antipsychotic|antipsychotic drugs]]. The structure of DRD2 in complex with the atypical antipsychotic [[risperidone]] has been determined.<ref name="pmid29466326">{{cite journal | vauthors = Wang S, Che T, Levit A, Shoichet BK, Wacker D, Roth BL | title = Structure of the D2 dopamine receptor bound to the atypical antipsychotic drug risperidone | journal = Nature | volume = 555 | issue = 7695 | pages = 269–273 | date = March 2018 | pmid = 29466326 | pmc = 5843546 | doi = 10.1038/nature25758 }}</ref><ref>{{Cite web|url=https://www.nimh.nih.gov/news/science-news/2018/molecular-secrets-revealed-antipsychotic-docked-in-its-receptor.shtml|title=NIMH » Molecular Secrets Revealed: Antipsychotic Docked in its Receptor|website=www.nimh.nih.gov|language=en|access-date=2018-11-26}}</ref>

== Function ==
This gene encodes the D2 subtype of the [[dopamine receptor]], which is coupled to Gi subtype of [[G protein-coupled receptor]]. This [[G protein-coupled receptor]] inhibits [[adenylyl cyclase]] activity.<ref name="pmid11089973">{{cite journal | vauthors = Usiello A, Baik JH, Rougé-Pont F, Picetti R, Dierich A, LeMeur M, Piazza PV, Borrelli E | title = Distinct functions of the two isoforms of dopamine D2 receptors | journal = Nature | volume = 408 | issue = 6809 | pages = 199–203 | date = November 2000 | pmid = 11089973 | doi = 10.1038/35041572 }}</ref>

In mice, regulation of D2R surface expression by the [[neuronal calcium sensor-1]] (NCS-1) in the [[dentate gyrus]] is involved in exploration, [[synaptic plasticity]] and memory formation.<ref name="pmid19755107">{{cite journal | vauthors = Saab BJ, Georgiou J, Nath A, Lee FJ, Wang M, Michalon A, Liu F, Mansuy IM, Roder JC | title = NCS-1 in the dentate gyrus promotes exploration, synaptic plasticity, and rapid acquisition of spatial memory | journal = Neuron | volume = 63 | issue = 5 | pages = 643–56 | date = September 2009 | pmid = 19755107 | doi = 10.1016/j.neuron.2009.08.014 }}</ref> A recent study has shown a potential role for D2R in retrieval of fear memories in the prelimbic cortex.<ref>{{cite journal | vauthors = Madsen HB, Guerin AA, Kim JH | title = Investigating the role of dopamine receptor- and parvalbumin-expressing cells in extinction of conditioned fear | journal = Neurobiology of Learning and Memory | volume = 145 | pages = 7–17 | date = November 2017 | pmid = 28842281 | doi = 10.1016/j.nlm.2017.08.009 }}</ref>

In flies, activation of the D2 [[autoreceptor]] protected dopamine neurons from cell death induced by [[MPP+]], a toxin mimicking [[Parkinson's disease]] pathology.<ref name="pmid23452092">{{cite journal | vauthors = Wiemerslage L, Schultz BJ, Ganguly A, Lee D | title = Selective degeneration of dopaminergic neurons by MPP(+) and its rescue by D2 autoreceptors in Drosophila primary culture | journal = Journal of Neurochemistry | volume = 126 | issue = 4 | pages = 529–40 | date = August 2013 | pmid = 23452092 | pmc = 3737274 | doi = 10.1111/jnc.12228 }}</ref>

== Isoforms{{anchor|D2sh}} ==

[[Alternative splicing]] of this gene results in three transcript variants encoding different [[isoform]]s.<ref name="entrez">{{cite web | title = Entrez Gene: DRD2 dopamine receptor D2| url = https://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=1813 }}</ref>

The long form ('''D2Lh''') has the "canonical" sequence and functions as a classic post-[[Synapse|synaptic]] receptor.<ref name="D2 Long and short">{{cite journal | vauthors = Beaulieu JM, Gainetdinov RR | title = The physiology, signaling, and pharmacology of dopamine receptors | journal = Pharmacological Reviews | volume = 63 | issue = 1 | pages = 182–217 | date = March 2011 | pmid = 21303898 | doi = 10.1124/pr.110.002642 }}</ref> The short form ('''D2Sh''') is pre-synaptic and functions as an [[autoreceptor]] that regulates the levels of dopamine in the synaptic cleft.<ref name="D2 Long and short" /> [[agonist|Agonism]] of D2sh receptors inhibits dopamine release; antagonism increases [[dopaminergic]] release.<ref name="D2 Long and short" /> A third D2(Longer) form differs from the canonical sequence where 270V is replaced by VVQ.<ref name = "uniprot">{{UniProt Full|P14416|D(2) dopamine receptor}}</ref>

== Active (D2''High''R) and inactive (D2''Low''R) forms ==
D2R conformers are equilibrated between two full active (D2''High''R) and inactive (D2''Low''R) states, while in complex with an [[agonist]] and [[antagonist]] ligand, respectively.

The monomeric inactive conformer of D2R in binding with [[Risperidone]] was reported in 2018 ([[Protein Data Bank|PDB]] ID: 6CM4). However, the active form which is generally bound to an agonist, is not available yet and in most of the studies the [[Homology modeling]] of the structure is implemented. The difference between the active and inactive of [[G protein-coupled receptor]] is mainly observed as conformational changes at the cytoplasmic half of the structure, particularly at the [[transmembrane domain]]s (TM) 5 and 6. The conformational transitions occurred at the cytoplasmic ends are due to the coupling of [[G protein]] to the cytoplasmic loop between the TM 5 and 6.<ref>{{cite journal | vauthors = Salmas RE, Yurtsever M, Stein M, Durdagi S | title = Modeling and protein engineering studies of active and inactive states of human dopamine D2 receptor (D2R) and investigation of drug/receptor interactions | journal = Molecular Diversity | volume = 19 | issue = 2 | pages = 321–32 | date = May 2015 | pmid = 25652238 | doi = 10.1007/s11030-015-9569-3 }}</ref>

It was observed that either D2R [[agonist]] or [[antagonist]] ligands revealed better [[Binding affinity|binding affinities]] inside the ligand-binding domain of the active D2R in comparison with the inactive state. It demonstrated that ligand-binding domain of D2R is affected by the conformational changes occurring at the cytoplasmic domains of the TM 5 and 6. In consequence, the D2R activation reflects a positive cooperation on the ligand-binding domain.

In drug discovery studies in order to calculate the binding affinities of the D2R ligands inside the binding domain, it's important to work on which form of D2R. It's known that the full active and inactive states are recommended to be used for the agonist and antagonist studies, respectively.

Any disordering in equilibration of D2R states, which causes problems in signal transferring between the nervous systems, may lead to diverse serious disorders, such as [[Schizophrenia]], [[autism]] and [[Parkinson's disease]].<ref>{{cite journal | vauthors = Seeman P, Chau-Wong M, Tedesco J, Wong K | title = Brain receptors for antipsychotic drugs and dopamine: direct binding assays | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 72 | issue = 11 | pages = 4376–80 | date = November 1975 | pmid = 1060115 | doi = 10.1073/pnas.72.11.4376 }}</ref> In order to control these disorders, equilibration between the D2R states is controlled by implementing of agonist and antagonist D2R ligands. In most cases, it was observed that the problems regarding the D2R states may have genetic roots and are controlled by drug therapies. So far, there is no any certain treatment for these mental disorders.

== Oligomerization of D2R ==
It was observed that D2R exists in dimeric forms or higher order oligomers.<ref>{{cite journal | vauthors = Armstrong D, Strange PG | title = Dopamine D2 receptor dimer formation: evidence from ligand binding | journal = The Journal of Biological Chemistry | volume = 276 | issue = 25 | pages = 22621–9 | date = June 2001 | pmid = 11278324 | doi = 10.1074/jbc.M006936200 }}</ref> There are some experimental and molecular modeling evidences that demonstrated the D2R monomers cross link from their TM 4 and TM 5 to form dimeric conformers.<ref>{{cite journal | vauthors = Guo W, Shi L, Javitch JA | title = The fourth transmembrane segment forms the interface of the dopamine D2 receptor homodimer | journal = The Journal of Biological Chemistry | volume = 278 | issue = 7 | pages = 4385–8 | date = February 2003 | pmid = 12496294 | doi = 10.1074/jbc.C200679200 }}</ref><ref>{{cite journal | vauthors = Durdagi S, Salmas RE, Stein M, Yurtsever M, Seeman P | title = Binding Interactions of Dopamine and Apomorphine in D2High and D2Low States of Human Dopamine D2 Receptor Using Computational and Experimental Techniques | language = EN | journal = ACS Chemical Neuroscience | volume = 7 | issue = 2 | pages = 185–95 | date = February 2016 | pmid = 26645629 | doi = 10.1021/acschemneuro.5b00271 }}</ref> Oligomerization of D2R has a main role in their biological activities and any disordering in it may lead to mental diseases. It's known that the D2R ligands (either the agonist or antagonist) binding to the ligand-binding domain of D2R are independent of oligomerization and can not have any effect on its process, so the drugs used for the treatment of mental diseases can't cause any main problem in oligomerization of D2R. Since the process of oligomerization of D2R in human bodies and their links to the mental diseases were not explicitly studied, there is no any treatment reported for the disorders originates from oligomerization's problems.

The oligomerization of GPCRs is a controversial topic that there are many unknown problems on this area yet. There's not any crystallographic data available describing the crosslinking of monomers. There are some evidences suggesting that GPCRs monomers crosslinking domains are different and dependent to the biological environments and other factors.

== Genetics ==
[[Allele|Allelic]] variants:
* [[A-241G]]
* [[C132T]], [[G423A]], [[T765C]], [[C939T]], [[C957T]], and [[G1101A]]<ref name="pmid12554675">{{cite journal | vauthors = Duan J, Wainwright MS, Comeron JM, Saitou N, Sanders AR, Gelernter J, Gejman PV | title = Synonymous mutations in the human dopamine receptor D2 (DRD2) affect mRNA stability and synthesis of the receptor | journal = Human Molecular Genetics | volume = 12 | issue = 3 | pages = 205–16 | date = February 2003 | pmid = 12554675 | doi = 10.1093/hmg/ddg055 }}</ref>
* [[Cys311Ser]]
* -141C insertion/deletion<ref name="pmid9097961">{{cite journal | vauthors = Arinami T, Gao M, Hamaguchi H, Toru M | title = A functional polymorphism in the promoter region of the dopamine D2 receptor gene is associated with schizophrenia | journal = Human Molecular Genetics | volume = 6 | issue = 4 | pages = 577–82 | date = April 1997 | pmid = 9097961 | doi = 10.1093/hmg/6.4.577 }}</ref> The polymorphisms have been investigated with respect to association with [[schizophrenia]].<ref name="pmid15211624">{{cite journal | vauthors = Glatt SJ, Faraone SV, Tsuang MT | title = DRD2 -141C insertion/deletion polymorphism is not associated with schizophrenia: results of a meta-analysis | journal = American Journal of Medical Genetics. Part B, Neuropsychiatric Genetics | volume = 128B | issue = 1 | pages = 21–3 | date = July 2004 | pmid = 15211624 | doi = 10.1002/ajmg.b.30007 }}</ref>

Some researchers have previously associated the [[Polymorphism (biology)|polymorphism]] Taq 1A ([[rs1800497]]) to the ''DRD2'' gene.
However, the polymorphism resides in [[exon]] 8 of the ''[[ANKK1]]'' gene.<ref name="pmid18621654">{{cite journal | vauthors = Lucht M, Rosskopf D | title = Comment on "Genetically determined differences in learning from errors" | journal = Science | volume = 321 | issue = 5886 | pages = 200; author reply 200 | date = July 2008 | pmid = 18621654 | doi = 10.1126/science.1155372 }}</ref> DRD2 TaqIA polymorphism has been reported to be associated with an increased risk for developing motor
fluctuations but not hallucinations in Parkinson's disease.<ref name="pmid11425949">{{cite journal | vauthors = Wang J, Liu ZL, Chen B | title = Association study of dopamine D2, D3 receptor gene polymorphisms with motor fluctuations in PD | journal = Neurology | volume = 56 | issue = 12 | pages = 1757–9 | date = June 2001 | pmid = 11425949 | doi = 10.1212/WNL.56.12.1757 }}</ref><ref name="Wang J, Zhao c, Chen B, Liu Z. 2004">{{cite journal | vauthors = Wang J, Zhao C, Chen B, Liu ZL | title = Polymorphisms of dopamine receptor and transporter genes and hallucinations in Parkinson's disease | journal = Neuroscience Letters | volume = 355 | issue = 3 | pages = 193–6 | date = January 2004 | pmid = 14732464 | doi = 10.1016/j.neulet.2003.11.006 }}</ref>

== Ligands ==
Most of the older [[antipsychotic]] drugs such as [[chlorpromazine]] and [[haloperidol]] are antagonists for the dopamine D2 receptor, but are, in general, very unselective, at best selective only for the "D2-like family" receptors and so binding to D2, D3 and D4, and often also to many other receptors such as those for [[serotonin]] and [[histamine]], resulting in a range of side-effects and making them poor agents for scientific research. In similar manner, older dopamine agonists used for [[Parkinson's disease]] such as [[bromocriptine]] and [[cabergoline]] are poorly selective for one dopamine receptor over another, and, although most of these agents do act as D2 agonists, they affect other subtypes as well. Several selective D2 [[ligand (biochemistry)|ligands]] are, however, now available, and this number is likely to increase as further research progresses.

===Agonists===
{{div col|colwidth=33em}}
* [[Bromocriptine]] – full agonist
* [[Cabergoline]] (Dostinex)
* [[N,N-Propyldihydrexidine]] – analogue of the D1/D5 agonist [[dihydrexidine]]; Selective for postsynaptic D2 receptor over the presynaptic D2 [[autoreceptor]].
* [[Piribedil]] – also D3 receptor agonist and [[α2-adrenergic receptor|α2–adrenergic antagonist]]
* [[Pramipexole]] – also D3, D4 receptor agonist
* [[Quinelorane]] – affinity for D2 > D3
* [[Quinpirole]] – also D3 receptor agonist
* [[Ropinirole]] – full agonist
* [[Sumanirole]] – full agonist; highly selective
* [[Talipexole]] – selective for D2 over other dopamine receptors, but also acts as α2–adrenoceptor agonist and 5-HT3 antagonist.
{{Div col end}}

===Partial agonists===
{{div col|colwidth=33em}}
* [[Aplindore]]
* [[Aripiprazole]]<ref name="Rxlist - Abilify">{{cite web | url = http://www.rxlist.com/abilify-drug.htm | title = Clinical Pharmacology for Abilify | author = | authorlink = | date = 2010-01-21 | work = | publisher = RxList.com | pages = | archive-url = | archive-date = | quote = | access-date = 2010-01-21}}</ref>
* [[Armodafinil]] – although primarily thought to be a weak DAT inhibitor, armodafinil is also a D2 partial agonist.<ref name="pmid19391150">{{cite journal | vauthors = Seeman P, Guan HC, Hirbec H | title = Dopamine D2High receptors stimulated by phencyclidines, lysergic acid diethylamide, salvinorin A, and modafinil | journal = Synapse | volume = 63 | issue = 8 | pages = 698–704 | date = August 2009 | pmid = 19391150 | doi = 10.1002/syn.20647 }}</ref>
* [[Brexpiprazole]]
* [[Cariprazine]]
* [[GSK-789,472]] – Also D3 antagonist, with good selectivity over other receptors <ref name="pmid20153647">{{cite journal | vauthors = Holmes IP, Blunt RJ, Lorthioir OE, Blowers SM, Gribble A, Payne AH, Stansfield IG, Wood M, Woollard PM, Reavill C, Howes CM, Micheli F, Di Fabio R, Donati D, Terreni S, Hamprecht D, Arista L, Worby A, Watson SP | title = The identification of a selective dopamine D2 partial agonist, D3 antagonist displaying high levels of brain exposure | journal = Bioorganic & Medicinal Chemistry Letters | volume = 20 | issue = 6 | pages = 2013–6 | date = March 2010 | pmid = 20153647 | doi = 10.1016/j.bmcl.2010.01.090 }}</ref>
* [[Ketamine]] (also NMDA antagonist)
*[[2-Phenethylamine]] – (also a TAAR1 agonist and GABAb antagonist with effects at AMPA receptors)
* [[LSD]] – in vitro, LSD was found to be a partial agonist and potentiates dopamine-mediated prolactin secretion in lactotrophs.<ref name="pmid9698051">{{cite journal | vauthors = Giacomelli S, Palmery M, Romanelli L, Cheng CY, Silvestrini B | title = Lysergic acid diethylamide (LSD) is a partial agonist of D2 dopaminergic receptors and it potentiates dopamine-mediated prolactin secretion in lactotrophs in vitro | journal = Life Sciences | volume = 63 | issue = 3 | pages = 215–22 | year = 1998 | pmid = 9698051 | doi = 10.1016/S0024-3205(98)00262-8 }}</ref> LSD is also a 5-HT2A agonist.
* [[OSU-6162]] – also 5-HT2A partial agonist, acts as "dopamine stabilizer"
* [[Roxindole]] (only at the D2 autoreceptors)
* [[RP5063]]
* [[Salvinorin A]] – also [[Κ-opioid receptor|κ-opioid agonist]].
{{Div col end}}

===Antagonists===
{{div col|colwidth=33em}}
* [[Atypical antipsychotics]] (except aripiprazole, brexpiprazole, and any other D2 receptor partial agonists)
* [[Cinnarizine]]
* [[Chloroethylnorapomorphine]]
* [[Desmethoxyfallypride]]
* [[Domperidone]] – D2 and D3 antagonist; does not cross the blood-brain barrier
* [[Metoclopramide]] - Antiemetic - crosses Blood-brain Barrier - causes drug induced Parkinsonism.
* [[Eticlopride]]
* [[Fallypride]]
* [[Hydroxyzine]] (Vistaril, Atarax)
* [[Itopride]]
* [[L-741,626]] – highly selective D2 antagonist
* C11 [[Raclopride]] radiolabled – commonly employed in [[positron emission tomography]] studies<ref name="pmid15256343">{{cite journal | vauthors = Wang GJ, Volkow ND, Thanos PK, Fowler JS | title = Similarity between obesity and drug addiction as assessed by neurofunctional imaging: a concept review | journal = Journal of Addictive Diseases | volume = 23 | issue = 3 | pages = 39–53 | year = 2004 | pmid = 15256343 | doi = 10.1300/J069v23n03_04 }}</ref>
* [[Typical antipsychotics]]
* SV 293<ref>{{cite journal | vauthors = Huang R, Griffin SA, Taylor M, Vangveravong S, Mach RH, Dillon GH, Luedtke RR | title = The effect of SV 293, a D2 dopamine receptor-selective antagonist, on D2 receptor-mediated GIRK channel activation and adenylyl cyclase inhibition | journal = Pharmacology | volume = 92 | issue = 1-2 | pages = 84–9 | year = 2013 | pmid = 23942137 | doi = 10.1159/000351971 }}</ref>
* [[Yohimbine]]
* [[Buspirone]] D2 presynaptic autoreceptors (low dose) and postsynaptic D2 receptors (at higher doses) antagonist<ref>{{cite journal | vauthors = Lechin F, van der Dijs B, Jara H, Orozco B, Baez S, Benaim M, Lechin M, Lechin A | title = Effects of buspirone on plasma neurotransmitters in healthy subjects | journal = Journal of Neural Transmission | volume = 105 | issue = 6-7 | pages = 561–73 | date = 1998 | pmid = 9826102 | doi = 10.1007/s007020050079 }}</ref>

;[[#Isoforms|D2sh]] selective (presynaptic autoreceptors)
* [[Amisulpride]] (low doses)
* [[UH-232]]
{{Div col end}}

===Allosteric modulators===
{{div col|colwidth=33em}}
* [[Homocysteine]] – negative [[allosteric modulator]]<ref>{{cite journal | vauthors = Agnati LF, Ferré S, Genedani S, Leo G, Guidolin D, Filaferro M, Carriba P, Casadó V, Lluis C, Franco R, Woods AS, Fuxe K | title = Allosteric modulation of dopamine D2 receptors by homocysteine | journal = Journal of Proteome Research | volume = 5 | issue = 11 | pages = 3077–83 | date = November 2006 | pmid = 17081059 | doi = 10.1021/pr0601382 }}</ref>
* [[PAOPA]]<ref>{{cite journal | vauthors = Beyaert MG, Daya RP, Dyck BA, Johnson RL, Mishra RK | title = PAOPA, a potent dopamine D2 receptor allosteric modulator, prevents and reverses behavioral and biochemical abnormalities in an amphetamine-sensitized preclinical animal model of schizophrenia | journal = European Neuropsychopharmacology | volume = 23 | issue = 3 | pages = 253–62 | date = March 2013 | pmid = 22658400 | doi = 10.1016/j.euroneuro.2012.04.010 }}</ref>
* SB-269,652 <ref name="pmid25108820">{{cite journal | vauthors = Lane JR, Donthamsetti P, Shonberg J, Draper-Joyce CJ, Dentry S, Michino M, Shi L, López L, Scammells PJ, Capuano B, Sexton PM, Javitch JA, Christopoulos A | title = A new mechanism of allostery in a G protein-coupled receptor dimer | journal = Nature Chemical Biology | volume = 10 | issue = 9 | pages = 745–52 | date = September 2014 | pmid = 25108820 | pmc = 4138267 | doi = 10.1038/nchembio.1593 }}</ref><ref name="pmid25453482">{{cite journal | vauthors = Maggio R, Scarselli M, Capannolo M, Millan MJ | title = Novel dimensions of D3 receptor function: Focus on heterodimerisation, transactivation and allosteric modulation | journal = European Neuropsychopharmacology | volume = 25 | issue = 9 | pages = 1470–9 | date = September 2015 | pmid = 25453482 | doi = 10.1016/j.euroneuro.2014.09.016 }}</ref><ref>{{cite journal | vauthors = Silvano E, Millan MJ, Mannoury la Cour C, Han Y, Duan L, Griffin SA, Luedtke RR, Aloisi G, Rossi M, Zazzeroni F, Javitch JA, Maggio R | title = The tetrahydroisoquinoline derivative SB269,652 is an allosteric antagonist at dopamine D3 and D2 receptors | journal = Molecular Pharmacology | volume = 78 | issue = 5 | pages = 925–34 | date = November 2010 | pmid = 20702763 | pmc = 2981362 | doi = 10.1124/mol.110.065755 }}</ref>
{{Div col end}}

=== Heterobivalent ligands ===
* 1-(6-(((''R'',''S'')-7-Hydroxychroman-2-yl)methylamino]hexyl)-3-((''S'')-1-methylpyrrolidin-2-yl)pyridinium bromide (compound 2, D2R agonist and [[Nicotinic acetylcholine receptor|nAChR]] antagonist)<ref>{{cite journal | vauthors = Matera C, Pucci L, Fiorentini C, Fucile S, Missale C, Grazioso G, Clementi F, Zoli M, De Amici M, Gotti C, Dallanoce C | title = Bifunctional compounds targeting both D2 and non-α7 nACh receptors: design, synthesis and pharmacological characterization | journal = European Journal of Medicinal Chemistry | volume = 101 | pages = 367–83 | date = August 2015 | pmid = 26164842 | doi = 10.1016/j.ejmech.2015.06.039 }}</ref>

=== Functionally selective ligands ===
* UNC9994<ref>{{cite journal | vauthors = Allen JA, Yost JM, Setola V, Chen X, Sassano MF, Chen M, Peterson S, Yadav PN, Huang XP, Feng B, Jensen NH, Che X, Bai X, Frye SV, Wetsel WC, Caron MG, Javitch JA, Roth BL, Jin J | title = Discovery of β-arrestin-biased dopamine D2 ligands for probing signal transduction pathways essential for antipsychotic efficacy | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 108 | issue = 45 | pages = 18488–93 | date = November 2011 | pmid = 22025698 | pmc = 3215024 | doi = 10.1073/pnas.1104807108 }}</ref>

==Protein–protein interactions==
The dopamine receptor D2 has been shown to [[Protein–protein interaction|interact]] with [[EPB41L1]],<ref name="pmid12181426">{{cite journal | vauthors = Binda AV, Kabbani N, Lin R, Levenson R | title = D2 and D3 dopamine receptor cell surface localization mediated by interaction with protein 4.1N | journal = Molecular Pharmacology | volume = 62 | issue = 3 | pages = 507–13 | date = September 2002 | pmid = 12181426 | doi = 10.1124/mol.62.3.507 }}</ref> [[PPP1R9B]]<ref name="pmid10391935">{{cite journal | vauthors = Smith FD, Oxford GS, Milgram SL | title = Association of the D2 dopamine receptor third cytoplasmic loop with spinophilin, a protein phosphatase-1-interacting protein | journal = The Journal of Biological Chemistry | volume = 274 | issue = 28 | pages = 19894–900 | date = July 1999 | pmid = 10391935 | doi = 10.1074/jbc.274.28.19894 }}</ref> and [[NCS-1]].<ref name="pmid12351722">{{cite journal | vauthors = Kabbani N, Negyessy L, Lin R, Goldman-Rakic P, Levenson R | title = Interaction with neuronal calcium sensor NCS-1 mediates desensitization of the D2 dopamine receptor | journal = The Journal of Neuroscience | volume = 22 | issue = 19 | pages = 8476–86 | date = October 2002 | pmid = 12351722 }}</ref>

===Receptor oligomers===
The D2 receptor forms [[GPCR oligomer|receptor heterodimers]] ''[[in vivo]]'' (i.e., in living animals) with other [[G protein-coupled receptors]]; these include:<ref name="DA receptor heterodimers">{{cite journal | vauthors = Beaulieu JM, Espinoza S, Gainetdinov RR | title = Dopamine receptors - IUPHAR Review 13 | journal = British Journal of Pharmacology | volume = 172 | issue = 1 | pages = 1–23 | date = January 2015 | pmid = 25671228 | pmc = 4280963 | doi = 10.1111/bph.12906 }}</ref>
*[[D1–D2 dopamine receptor heteromer|D1–D2 dopamine receptor heteromer]]
*D2–[[Adenosine A2A receptor|adenosine A2A]]
*D2–[[ghrelin receptor]]
*[[#D2sh|D2sh]]–[[TAAR1]]{{#tag:ref|D2sh–TAAR1 is a presynaptic [[heterodimer]] which involves the relocation of TAAR1 from the intracellular space to D2sh at the [[plasma membrane]], increased D2sh agonist [[binding affinity]], and [[signal transduction]] through the calcium–[[protein kinase C|PKC]]–[[NFAT]] pathway and [[G-protein]] independent [[Protein kinase B|PKB]]–[[GSK3]] pathway.<ref name="Miller+Grandy 2016">{{cite journal | vauthors = Grandy DK, Miller GM, Li JX | title = "TAARgeting Addiction"--The Alamo Bears Witness to Another Revolution: An Overview of the Plenary Symposium of the 2015 Behavior, Biology and Chemistry Conference | journal = Drug and Alcohol Dependence | volume = 159 | issue = | pages = 9–16 | date = February 2016 | pmid = 26644139 | pmc = 4724540 | doi = 10.1016/j.drugalcdep.2015.11.014 | quote = This original observation of TAAR1 and DA D2R interaction has subsequently been confirmed and expanded upon with observations that both receptors can heterodimerize with each other under certain conditions ... Additional DA D2R/TAAR1 interactions with functional consequences are revealed by the results of experiments demonstrating that in addition to the cAMP/PKA pathway (Panas et al., 2012) stimulation of TAAR1-mediated signaling is linked to activation of the Ca++/PKC/NFAT pathway (Panas et al.,2012) and the DA D2R-coupled, G protein-independent AKT/GSK3 signaling pathway (Espinoza et al., 2015; Harmeier et al., 2015), such that concurrent TAAR1 and DA DR2R activation could result in diminished signaling in one pathway (e.g. cAMP/PKA) but retention of signaling through another (e.g., Ca++/PKC/NFA) }}</ref><ref name="TAAR1-D2sh">{{cite journal | vauthors = Harmeier A, Obermueller S, Meyer CA, Revel FG, Buchy D, Chaboz S, Dernick G, Wettstein JG, Iglesias A, Rolink A, Bettler B, Hoener MC | title = Trace amine-associated receptor 1 activation silences GSK3β signaling of TAAR1 and D2R heteromers | journal = European Neuropsychopharmacology | volume = 25 | issue = 11 | pages = 2049–61 | date = November 2015 | pmid = 26372541 | doi = 10.1016/j.euroneuro.2015.08.011 | quote = Interaction of TAAR1 with D2R altered the subcellular localization of TAAR1 and increased D2R agonist binding affinity. }}</ref>|group="note"}}

The D2 receptor has been shown to form hetorodimers ''[[in vitro]]'' (and possibly ''in vivo'') with [[Dopamine D3 receptor|DRD3]],<ref>{{cite journal | vauthors = Maggio R, Millan MJ | title = Dopamine D2-D3 receptor heteromers: pharmacological properties and therapeutic significance | journal = Current Opinion in Pharmacology | volume = 10 | issue = 1 | pages = 100–7 | date = February 2010 | pmid = 19896900 | doi = 10.1016/j.coph.2009.10.001 }}</ref> [[Dopamine receptor D5|DRD5]],<ref>{{cite journal | vauthors = Hasbi A, O'Dowd BF, George SR | title = Heteromerization of dopamine D2 receptors with dopamine D1 or D5 receptors generates intracellular calcium signaling by different mechanisms | journal = Current Opinion in Pharmacology | volume = 10 | issue = 1 | pages = 93–9 | date = February 2010 | pmid = 19897420 | pmc = 2818238 | doi = 10.1016/j.coph.2009.09.011 }}</ref> and [[5-HT2A receptor|5-HT2A]].<ref>{{cite journal | vauthors = Albizu L, Holloway T, González-Maeso J, Sealfon SC | title = Functional crosstalk and heteromerization of serotonin 5-HT2A and dopamine D2 receptors | journal = Neuropharmacology | volume = 61 | issue = 4 | pages = 770–7 | date = September 2011 | pmid = 21645528 | pmc = 3556730 | doi = 10.1016/j.neuropharm.2011.05.023 }}</ref>

== See also ==
* [[Prolactin modulator]]

==Notes==
{{Reflist|group=note}}

== References ==
{{Reflist|2}}

== External links ==
* {{MeshName|Receptors,+Dopamine+D2}}
* {{cite web|last=Pappas|first=Stephanie|title=Study: Genes Influence Who Your Friends Are|url=http://www.livescience.com/health/genes-influence-friendships-110117.html|work=Imaginova Corp.|publisher=LiveScience|access-date=20 January 2011}}

{{NLM content}}
{{G protein-coupled receptors}}
{{Dopaminergics}}
{{Use dmy dates|date=January 2012}}

[[Category:Dopamine receptors]]
[[Category:Biology of attention deficit hyperactivity disorder]]
[[Category:Psychopharmacology]]

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Dopamine receptor D2