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 H. Snyder and Philip Seeman used a radiolabeled antipsychotic drug to identify what is now known as the dopamine D2 receptor.[5] The dopamine D2 receptor is the main receptor for most antipsychotic drugs. The structure of DRD2 in complex with the atypical antipsychotic risperidone has been determined.[6][7]
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D2 receptors are coupled to Gi subtype of G protein. This G protein-coupled receptor inhibits adenylyl cyclase activity.[8]
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.[9] Studies have shown potential roles for D2R in retrieval of fear memories in the prelimbic cortex[10] and in discrimination learning in the nucleus accumbens.[11]
In flies, activation of the D2 autoreceptor protected dopamine neurons from cell death induced by MPP+, a toxin mimicking Parkinson's disease pathology.[12]
While optimal dopamine levels favor D1R cognitive stabilization, it is the D2R that mediates the cognitive flexibility in humans.[13][14][15]
Alternative splicing of this gene results in three transcript variants encoding different isoforms.[16]
The long form (D2Lh) has the "canonical" sequence and functions as a classic post-synaptic receptor.[17] The short form (D2Sh) is pre-synaptic and functions as an autoreceptor that regulates the levels of dopamine in the synaptic cleft.[17] Agonism of D2sh receptors inhibits dopamine release; antagonism increases dopaminergic release.[17] A third D2(Longer) form differs from the canonical sequence where 270V is replaced by VVQ.[18]
D2R conformers are equilibrated between two full active (D2HighR) and inactive (D2LowR) 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 (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 domains (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.[19]
It was observed that either D2R agonist or antagonist ligands revealed better 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,[20] autism[citation needed] and Parkinson's disease.[citation needed] In order to assist in the management of these conditions, equilibration between the D2R states is controlled by implementing of agonist and antagonist D2R ligands.[citation needed] In most cases, it was observed that the problems regarding the D2R states may have genetic roots and are controlled by drug therapies.[citation needed] So far, there is no certain treatment for these mental disorders.
There is an orthosteric binding site (OBS), as well as a secondary binding pocket (SBP) on the dopamine 2 receptor, and interaction with the SBP is a requirement for allosteric pharmacology. The compound SB269652 is a negative allosteric modulator of the D2R.[21]
It was observed that D2R exists in dimeric forms or higher order oligomers.[22] 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.[23][24]
Allelic variants:
- A-241G
- C132T, G423A, T765C, C939T, C957T, and G1101A[25]
- Cys311Ser
- -141C insertion/deletion[26] The polymorphisms have been investigated with respect to association with schizophrenia.[27]
Some researchers have previously associated the polymorphism Taq 1A (rs1800497) to the DRD2 gene.
However, the polymorphism resides in exon 8 of the ANKK1 gene.[28] DRD2 TaqIA polymorphism has been reported to be associated with an increased risk for developing motor
fluctuations but not hallucinations in Parkinson's disease.[29][30] A splice variant in Dopamine receptor D2(rs1076560) was found to be associated with limb truncal Tardive dyskinesia and diminished expression factor of Positive and Negative Syndrome Scale (PANSS) in schizophrenia subjects.[31]
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 ligands are, however, now available, and this number is likely to increase as further research progresses.
Antagonists
- D2sh selective (presynaptic autoreceptors)
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 nAChR antagonist)[47]
Dual D2AR/ A2AAR ligands
- Dual agonists for A2AAR and D2AR receptors have been developed.[48]
Functionally selective ligands
The dopamine receptor D2 has been shown to interact with EPB41L1,[50] PPP1R9B[51] and NCS-1.[52]
Saab BJ, Georgiou J, Nath A, Lee FJ, Wang M, Michalon A, Liu F, Mansuy IM, Roder JC (September 2009). "NCS-1 in the dentate gyrus promotes exploration, synaptic plasticity, and rapid acquisition of spatial memory". Neuron. 63 (5): 643–56. doi:10.1016/j.neuron.2009.08.014. PMID 19755107. S2CID 5321020. Madsen HB, Guerin AA, Kim JH (November 2017). "Investigating the role of dopamine receptor- and parvalbumin-expressing cells in extinction of conditioned fear". Neurobiology of Learning and Memory. 145: 7–17. doi:10.1016/j.nlm.2017.08.009. PMID 28842281. S2CID 26875742. Universal protein resource accession number P14416 for "D(2) dopamine receptor" at UniProt. Salmas RE, Yurtsever M, Stein M, Durdagi S (May 2015). "Modeling and protein engineering studies of active and inactive states of human dopamine D2 receptor (D2R) and investigation of drug/receptor interactions". Molecular Diversity. 19 (2): 321–32. doi:10.1007/s11030-015-9569-3. PMID 25652238. S2CID 1636767. Draper-Joyce CJ, Michino M, Verma RK, Klein Herenbrink C, Shonberg J, Kopinathan A, Scammells PJ, Capuano B, Thal DM, Javitch JA, Christopoulos A, Shi L, Lane JR (February 2018). "2 receptor". Biochemical Pharmacology. 148: 315–328. doi:10.1016/j.bcp.2018.01.002. PMC 5800995. PMID 29325769. Durdagi S, Salmas RE, Stein M, Yurtsever M, Seeman P (February 2016). "Binding Interactions of Dopamine and Apomorphine in D2High and D2Low States of Human Dopamine D2 Receptor Using Computational and Experimental Techniques". ACS Chemical Neuroscience. 7 (2): 185–95. doi:10.1021/acschemneuro.5b00271. PMID 26645629. Glatt SJ, Faraone SV, Tsuang MT (July 2004). "DRD2 -141C insertion/deletion polymorphism is not associated with schizophrenia: results of a meta-analysis". American Journal of Medical Genetics. Part B, Neuropsychiatric Genetics. 128B (1): 21–3. doi:10.1002/ajmg.b.30007. PMID 15211624. S2CID 330601. Seeman P, Guan HC, Hirbec H (August 2009). "Dopamine D2High receptors stimulated by phencyclidines, lysergic acid diethylamide, salvinorin A, and modafinil". Synapse. 63 (8): 698–704. doi:10.1002/syn.20647. PMID 19391150. S2CID 17758902. 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 (March 2010). "The identification of a selective dopamine D2 partial agonist, D3 antagonist displaying high levels of brain exposure". Bioorganic & Medicinal Chemistry Letters. 20 (6): 2013–6. doi:10.1016/j.bmcl.2010.01.090. PMID 20153647. Giacomelli S, Palmery M, Romanelli L, Cheng CY, Silvestrini B (1998). "Lysergic acid diethylamide (LSD) is a partial agonist of D2 dopaminergic receptors and it potentiates dopamine-mediated prolactin secretion in lactotrophs in vitro". Life Sciences. 63 (3): 215–22. doi:10.1016/S0024-3205(98)00262-8. PMID 9698051. Sani G, Serra G, Kotzalidis GD, Romano S, Tamorri SM, Manfredi G, et al. (August 2012). "The role of memantine in the treatment of psychiatric disorders other than the dementias: a review of current preclinical and clinical evidence". CNS Drugs. 26 (8): 663–90. doi:10.2165/11634390-000000000-00000. PMID 22784018. S2CID 21597978. Wang GJ, Volkow ND, Thanos PK, Fowler JS (2004). "Similarity between obesity and drug addiction as assessed by neurofunctional imaging: a concept review". Journal of Addictive Diseases. 23 (3): 39–53. doi:10.1300/J069v23n03_04. PMID 15256343. S2CID 14589783. Huang R, Griffin SA, Taylor M, Vangveravong S, Mach RH, Dillon GH, Luedtke RR (2013). "The effect of SV 293, a D2 dopamine receptor-selective antagonist, on D2 receptor-mediated GIRK channel activation and adenylyl cyclase inhibition". Pharmacology. 92 (1–2): 84–9. doi:10.1159/000351971. PMID 23942137. S2CID 33761631. Lechin F, van der Dijs B, Jara H, Orozco B, Baez S, Benaim M, Lechin M, Lechin A (1998). "Effects of buspirone on plasma neurotransmitters in healthy subjects". Journal of Neural Transmission. 105 (6–7): 561–73. doi:10.1007/s007020050079. PMID 9826102. S2CID 12858061. Agnati LF, Ferré S, Genedani S, Leo G, Guidolin D, Filaferro M, Carriba P, Casadó V, Lluis C, Franco R, Woods AS, Fuxe K (November 2006). "Allosteric modulation of dopamine D2 receptors by homocysteine". Journal of Proteome Research. 5 (11): 3077–83. CiteSeerX 10.1.1.625.26. doi:10.1021/pr0601382. PMID 17081059. Beyaert MG, Daya RP, Dyck BA, Johnson RL, Mishra RK (March 2013). "PAOPA, a potent dopamine D2 receptor allosteric modulator, prevents and reverses behavioral and biochemical abnormalities in an amphetamine-sensitized preclinical animal model of schizophrenia". European Neuropsychopharmacology. 23 (3): 253–62. doi:10.1016/j.euroneuro.2012.04.010. PMID 22658400. S2CID 25146332. 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 (September 2014). "A new mechanism of allostery in a G protein-coupled receptor dimer". Nature Chemical Biology. 10 (9): 745–52. doi:10.1038/nchembio.1593. PMC 4138267. PMID 25108820. Maggio R, Scarselli M, Capannolo M, Millan MJ (September 2015). "Novel dimensions of D3 receptor function: Focus on heterodimerisation, transactivation and allosteric modulation". European Neuropsychopharmacology. 25 (9): 1470–9. doi:10.1016/j.euroneuro.2014.09.016. PMID 25453482. S2CID 25513707. 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 (November 2010). "The tetrahydroisoquinoline derivative SB269,652 is an allosteric antagonist at dopamine D3 and D2 receptors". Molecular Pharmacology. 78 (5): 925–34. doi:10.1124/mol.110.065755. PMC 2981362. PMID 20702763. Matera C, Pucci L, Fiorentini C, Fucile S, Missale C, Grazioso G, Clementi F, Zoli M, De Amici M, Gotti C, Dallanoce C (August 2015). "Bifunctional compounds targeting both D2 and non-α7 nACh receptors: design, synthesis and pharmacological characterization". European Journal of Medicinal Chemistry. 101: 367–83. doi:10.1016/j.ejmech.2015.06.039. PMID 26164842. 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 (November 2011). "Discovery of β-arrestin-biased dopamine D2 ligands for probing signal transduction pathways essential for antipsychotic efficacy". Proceedings of the National Academy of Sciences of the United States of America. 108 (45): 18488–93. Bibcode:2011PNAS..10818488A. doi:10.1073/pnas.1104807108. PMC 3215024. PMID 22025698. Binda AV, Kabbani N, Lin R, Levenson R (September 2002). "D2 and D3 dopamine receptor cell surface localization mediated by interaction with protein 4.1N". Molecular Pharmacology. 62 (3): 507–13. doi:10.1124/mol.62.3.507. PMID 12181426. S2CID 19901660. Grandy DK, Miller GM, Li JX (February 2016). ""TAARgeting Addiction"--The Alamo Bears Witness to Another Revolution: An Overview of the Plenary Symposium of the 2015 Behavior, Biology and Chemistry Conference". Drug and Alcohol Dependence. 159: 9–16. doi:10.1016/j.drugalcdep.2015.11.014. PMC 4724540. PMID 26644139. 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)
Harmeier A, Obermueller S, Meyer CA, Revel FG, Buchy D, Chaboz S, Dernick G, Wettstein JG, Iglesias A, Rolink A, Bettler B, Hoener MC (November 2015). "Trace amine-associated receptor 1 activation silences GSK3β signaling of TAAR1 and D2R heteromers". European Neuropsychopharmacology. 25 (11): 2049–61. doi:10.1016/j.euroneuro.2015.08.011. PMID 26372541. S2CID 41667764. Interaction of TAAR1 with D2R altered the subcellular localization of TAAR1 and increased D2R agonist binding affinity.
Maggio R, Millan MJ (February 2010). "Dopamine D2-D3 receptor heteromers: pharmacological properties and therapeutic significance". Current Opinion in Pharmacology. 10 (1): 100–7. doi:10.1016/j.coph.2009.10.001. PMID 19896900.
This article incorporates text from the United States National Library of Medicine, which is in the public domain.
