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Blex C, Michaelis S, Schrey AK, Furkert J, Eichhorst J, Bartho K, Gyapon Quast F, Marais A, Hakelberg M, Gruber U, Niquet S, Popp O, Kroll F, Sefkow M, Schülein R, Dreger M, Köster H. Targeting G Protein-Coupled Receptors by Capture Compound Mass Spectrometry: A Case Study with Sertindole. Chembiochem 2017; 18:1639-1649. [PMID: 28557180 DOI: 10.1002/cbic.201700152] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Indexed: 01/06/2023]
Abstract
Unbiased chemoproteomic profiling of small-molecule interactions with endogenous proteins is important for drug discovery. For meaningful results, all protein classes have to be tractable, including G protein-coupled receptors (GPCRs). These receptors are hardly tractable by affinity pulldown from lysates. We report a capture compound (CC)-based strategy to target and identify GPCRs directly from living cells. We synthesized CCs with sertindole attached to the CC scaffold in different orientations to target the dopamine D2 receptor (DRD2) heterologously expressed in HEK 293 cells. The structure-activity relationship of sertindole for DRD2 binding was reflected in the activities of the sertindole CCs in radioligand displacement, cell-based assays, and capture compound mass spectrometry (CCMS). The activity pattern was rationalized by molecular modelling. The most-active CC showed activities very similar to that of unmodified sertindole. A concentration of DRD2 in living cells well below 100 fmol used as an experimental input was sufficient for unambiguous identification of captured DRD2 by mass spectrometry. Our new CCMS workflow broadens the arsenal of chemoproteomic technologies to close a critical gap for the comprehensive characterization of drug-protein interactions.
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Affiliation(s)
- Christian Blex
- caprotec bioanalytics GmbH, Magnusstrasse 11, 12489, Berlin, Germany.,Present address: Department of Neurology and Experimental Neurology, Charité, University Medicine Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Simon Michaelis
- caprotec bioanalytics GmbH, Magnusstrasse 11, 12489, Berlin, Germany
| | - Anna K Schrey
- caprotec bioanalytics GmbH, Magnusstrasse 11, 12489, Berlin, Germany.,Institute for Physiology/Structural Bioinformatics Group, Charité, University Medicine Berlin, Philippstrasse 12, 10115, Berlin, Germany
| | - Jens Furkert
- Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle-Strasse 10, 13125, Berlin, Germany
| | - Jenny Eichhorst
- Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle-Strasse 10, 13125, Berlin, Germany
| | - Kathrin Bartho
- caprotec bioanalytics GmbH, Magnusstrasse 11, 12489, Berlin, Germany.,Thermo Fisher Scientific GmbH, Im Steingrund 4-6, 63303, Dreieich, Germany
| | - Frederick Gyapon Quast
- caprotec bioanalytics GmbH, Magnusstrasse 11, 12489, Berlin, Germany.,Glycotope GmbH, Robert-Rössle-Strasse 10, 13125, Berlin, Germany
| | - Anett Marais
- caprotec bioanalytics GmbH, Magnusstrasse 11, 12489, Berlin, Germany.,Medical Bioinformatics, Centogene AG, Schillingstrasse 68, 18057, Berlin, Germany
| | | | - Uschi Gruber
- caprotec bioanalytics GmbH, Magnusstrasse 11, 12489, Berlin, Germany
| | - Sylvia Niquet
- caprotec bioanalytics GmbH, Magnusstrasse 11, 12489, Berlin, Germany
| | - Oliver Popp
- caprotec bioanalytics GmbH, Magnusstrasse 11, 12489, Berlin, Germany
| | - Friedrich Kroll
- caprotec bioanalytics GmbH, Magnusstrasse 11, 12489, Berlin, Germany.,YARA International, Hanninghof 35, 48249, Duelmen, Germany
| | - Michael Sefkow
- caprotec bioanalytics GmbH, Magnusstrasse 11, 12489, Berlin, Germany.,Celares GmbH, Robert-Rössle-Strasse 10, 13125, Berlin, Germany
| | - Ralf Schülein
- Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle-Strasse 10, 13125, Berlin, Germany
| | - Mathias Dreger
- caprotec bioanalytics GmbH, Magnusstrasse 11, 12489, Berlin, Germany
| | - Hubert Köster
- caprotec bioanalytics GmbH, Magnusstrasse 11, 12489, Berlin, Germany
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Abstract
Antipsychotic drugs were introduced in the early 50s on the basis of clinical observations in patients with schizophrenia. Experimental studies later revealed that antagonism at the D(2) dopamine receptor is a common characteristic of all antipsychotic drugs. In the 80s, the advent of brain imaging technologies such as positron emission tomography (PET) allowed for direct noninvasive studies of drug binding in treated patients. The concept receptor occupancy is defined as the fraction (%) of a receptor population that is occupied during treatment with an unlabelled drug. With regard to antipsychotic drugs, the radioligand [(11) C]-raclopride has been the most widely used for binding to the D(2) /D(3) -dopamine receptors. The present review discusses the contribution from molecular imaging to the current understanding of mechanism of action (MoA) of antipsychotic drugs. Consistent initial PET-findings of high D2-receptor occupancy in the striatum of patients responding to different antipsychotic drug treatments provided clinical support for the dopamine hypothesis of antipsychotic drug action. It has subsequently been demonstrated that patients with extrapyramidal syndromes (EPS) have higher occupancy (above 80%) than patients with good response but no EPS (65-80%). The PET-defined interval for optimal antipsychotic drug treatment has been implemented in the evolvement of dose recommendations for classical as well as more recently developed drugs. Another consistent finding is lower D(2) -occupancy during treatment with the prototype atypical antipsychotic clozapine. The MoA of clozapine remains to be fully understood and may include nondopaminergic mechanisms. A general limitation is that currently available PET-radioligands are not selective for any of the five dopamine receptor subtypes. Current attempts at developing such ligands may provide the tools required to refine further the MoA of antipsychotic drugs.
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Affiliation(s)
- Magdalena Nord
- Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska University Hospital, Stockholm, Sweden.
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Zou S, Li L, Pei L, Vukusic B, Van Tol HHM, Lee FJS, Wan Q, Liu F. Protein-protein coupling/uncoupling enables dopamine D2 receptor regulation of AMPA receptor-mediated excitotoxicity. J Neurosci 2006; 25:4385-95. [PMID: 15858065 PMCID: PMC6725121 DOI: 10.1523/jneurosci.5099-04.2005] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
here is considerable evidence that dopamine D2 receptors can modulate AMPA receptor-mediated neurotoxicity. However, the molecular mechanism underlying this process remains essentially unclear. Here we report that D2 receptors inhibit AMPA-mediated neurotoxicity through two pathways: the activation of phosphoinositide-3 kinase (PI-3K) and downregulation of AMPA receptor plasma membrane expression, both involving a series of protein-protein coupling/uncoupling events. Agonist stimulation of D2 receptors promotes the formation of the direct protein-protein interaction between the third intracellular loop of the D2 receptor and the ATPase N-ethylmaleimide-sensitive factor (NSF) while uncoupling the NSF interaction with the carboxyl tail (CT) of the glutamate receptor GluR2 subunit of AMPA receptors. Previous studies have shown that full-length NSF directly couples to the GluR2CT and facilitates AMPA receptor plasma membrane expression. Furthermore, the CT region of GluR2 subunit is also responsible for several other intracellular protein couplings, including p85 subunit of PI-3K. Therefore, the direct coupling of D2-NSF and concomitant decrease in the NSF-GluR2 interaction results in a decrease of AMPA receptor membrane expression and an increase in the interaction between GluR2 and the p85 and subsequent activation of PI-3K. Disruption of the D2-NSF interaction abolished the ability of D2 receptor to attenuate AMPA-mediated neurotoxicity by blocking the D2 activation-induced changes in PI-3K activity and AMPA receptor plasma membrane expression. Furthermore, the D2-NSF-GluR2-p85 interactions are also responsible for the D2 inhibition of ischemia-induced cell death. These data may provide a new avenue to identify specific targets for therapeutics to modulate glutamate receptor-governed diseases, such as stroke.
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Affiliation(s)
- Shengwei Zou
- Department of Neuroscience, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada M5T 1R8
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Lee FJS, Wang YT, Liu F. Direct receptor cross-talk can mediate the modulation of excitatory and inhibitory neurotransmission by dopamine. J Mol Neurosci 2005; 26:245-52. [PMID: 16012198 DOI: 10.1385/jmn:26:2-3:245] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Dopamine is a neurotransmitter that can regulate both excitatory and inhibitory fast synaptic transmission. The overlapping dopaminergic, glutamatergic, and GABAergic systems provide a basis for the interaction between these three neurotransmitters. Although there is considerable evidence for the involvement of second-messenger systems to mediate receptor cross-talk between these receptor systems, there is emerging evidence that receptors can interact through direct protein-protein interactions. The functional implications and overall significance of the dopamine/glutamate/GABA interactions will be examined.
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Affiliation(s)
- Frank J S Lee
- Department of Neuroscience, Centre for Addiction and Mental Health, Clarke Division, University of British Columbia, Vancouver, British Columbia, V6T 2B5 Canada
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Iván G, Szigeti-Csúcs N, Oláh M, Nagy GM, Góth MI. Treatment of pituitary tumors: dopamine agonists. Endocrine 2005; 28:101-10. [PMID: 16311416 DOI: 10.1385/endo:28:1:101] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2005] [Accepted: 07/14/2005] [Indexed: 11/11/2022]
Abstract
The neurotransmitter/neuromodulator dopamine plays an important role in both the central nervous system and the periphery. In the hypothalamopituitary system its function is a dominant and tonic inhibitory regulation of pituitary hormone secretion including prolactin- and proopiomelanocortin-derived hormones. It is well known that dopamine agonists, such as bromocriptine, pergolide, quinagolide, cabergoline, and lisuride, can inhibit PRL secretion by binding to the D(2) dopamine receptors located on normal as well as tumorous pituitary cells. Moreover, they can effectively decrease excessive PRL secretion as well as the size of the tumor in patients having prolactinoma. Furthermore, dopamine agonists can also be used in other pituitary tumors. The major requirement for its use is that the tumor cells should express D(2) receptors. Therefore, in addition to prolactinomas, targets of dopamine agonist therapy are somatotroph tumors, nonfunctioning pituitary tumors, corticotroph pituitary tumors, Nelson's syndrome, gonadotropinomas, and thyrotropin-secreting pituitary tumors. It is also an option for the treatment of pituitary disease during pregnancy. Differences between the effectiveness and the resistance of different dopaminergic agents as well as the future perspectives of them in the therapy of pituitary tumors are discussed.
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Affiliation(s)
- Gabriella Iván
- Division of Endocrinology, Department of Medicine, National Medical Center, Budapest
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Hansen KA, Zhang Y, Colver R, Tho SPT, Plouffe L, McDonough PG. The dopamine receptor D2 genotype is associated with hyperprolactinemia. Fertil Steril 2005; 84:711-8. [PMID: 16169407 DOI: 10.1016/j.fertnstert.2005.03.040] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2004] [Revised: 03/21/2005] [Accepted: 03/21/2005] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate patients with hyperprolactinemia for the presence of dopamine receptor D2 polymorphisms. DESIGN Case-control study. SETTING Academic research environment. PATIENT(S) Women and men with pathologic hyperprolactinemia and healthy controls. INTERVENTION(S) DNA extraction of peripheral blood, polymerase chain reaction, single-strand conformation polymorphism, DNA sequencing, and restriction digest. MAIN OUTCOME MEASURE(S) Two polymorphisms in exon 7 of the dopamine receptor D2 (DRD2) gene. Polymorphism 1 involves nucleotide 3420 (C to T, 313 His), and polymorphism 2 involves nucleotide 3438 (C to T, 319 Pro). RESULT(S) The frequency of DRD2 polymorphism 1 alleles was increased in subjects with hyperprolactinemia. Analysis of the DRD2 genotypes demonstrates an odds ratio of 6.77 (2.39, 19.14; 95% confidence interval) for the polymorphism 1 homozygous state in hyperprolactinemia. CONCLUSION(S) A genetic predisposition to hyperprolactinemia is suggested by an excess homozygosity for polymorphism 1 in exon 7 of the DRD2 gene. Previous studies of lactotrophs from prolactinomas have found normal DRD2 receptors but differing isoform density. Homozygosity of polymorphism 1 may influence the distribution of the DRD2 isoforms on the lactotroph. Other potential mechanisms include an association with a molecular defect in a postreceptor signaling mechanism, such as a somatic inactivating mutation in a G1 protein, which could result in autonomous function of the lactotroph. Mutations could also result in different receptor-G protein interactions, such as a Gs instead of Gi, and result in autonomous lactotroph function.
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Affiliation(s)
- Keith A Hansen
- Department of Obstetrics and Gynecology, University of South Dakota School of Medicine, Sioux Falls, South Dakota 57105, USA.
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Tan S, Hermann B, Borrelli E. Dopaminergic mouse mutants: investigating the roles of the different dopamine receptor subtypes and the dopamine transporter. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2003; 54:145-97. [PMID: 12785287 DOI: 10.1016/s0074-7742(03)54005-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Shirlee Tan
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, BP 10142 Illkirch, C.U. de Strasbourg, France
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Mandell AJ, Selz KA, Owens MJ, Kinkead B, Shlesinger MF, Gutman DA, Arguragi V. Cellular and behavioral effects of D2 dopamine receptor hydrophobic eigenmode-targeted peptide ligands. Neuropsychopharmacology 2003; 28 Suppl 1:S98-107. [PMID: 12827150 DOI: 10.1038/sj.npp.1300134] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Patterns in G-protein-coupled receptors' hydrophobically transformed amino-acid sequences can be computationally characterized as hierarchies of autocorrelation waves, "hydrophobic eigenmodes", using autocovariance matrix decomposition and all poles power spectral and wavelet transformations. L- or D-amino acid (retro-inverso) 12-18 residue peptides targeting these modes can be designed using eigenvector templates derived from these computations. In all, 12 human long-form D(2) dopamine receptor eigenmode-targeted 15 mer peptides were designed, synthesized, and shown to modulate and/or indirectly activate the extracellular acidification response, EAR, in stably receptor-transfected CHO and LtK cells, with an 83% hit rate. Representative L- and D-amino-acid retro-inverso peptides injected bilaterally in the nucleus accumbens demonstrated changes in rat exploratory behavior and prepulse inhibition similar to those observed following parenteral amphetamine. In contrast with geometric models used for ligand design, such as pharmacophores, the hydrophobic eigenmode approach to lead modulatory peptide design targets hydrophobic eigenmode-bearing subsequences, including those not visible from X-ray and NMR studies such as extracellular segments and loops.
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Affiliation(s)
- Arnold J Mandell
- Cielo Institute, 486 Sunset Drive, Asheville, NC 28804-3727, USA.
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Humphries MA, Mustard JA, Hunter SJ, Mercer A, Ward V, Ebert PR. Invertebrate D2 type dopamine receptor exhibits age-based plasticity of expression in the mushroom bodies of the honeybee brain. JOURNAL OF NEUROBIOLOGY 2003; 55:315-30. [PMID: 12717701 DOI: 10.1002/neu.10209] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We have isolated a cDNA clone from the honeybee brain encoding a dopamine receptor, AmDop2, which is positively coupled to adenylyl cyclase. The transmembrane domains of this receptor are 88% identical to the orthologous Drosophila D2 dopamine receptor, DmDop2, though phylogenetic analysis and sequence homology both indicate that invertebrate and vertebrate D2 receptors are quite distinct. In situ hybridization to mRNA in whole-mount preparations of honeybee brains reveals gene expression in the mushroom bodies, a primary site of associative learning. Furthermore, two anatomically distinct cell types in the mushroom bodies exhibit differential regulation of AmDop2 expression. In all nonreproductive females (worker caste) and reproductive males (drones) the receptor gene is strongly and constitutively expressed in all mushroom body interneurons with small cell bodies. In contrast, the large cell-bodied interneurons exhibit dramatic plasticity of AmDop2 gene expression. In newly emerged worker bees (cell-cleaning specialists) and newly emerged drones, no AmDop2 transcript is observed in the large interneurons whereas this transcript is abundant in these cells in the oldest worker bees (resource foragers) and older drones. Differentiation of the mushroom body interneurons into two distinct classes (i.e., plastic or nonplastic with respect to AmDop2 gene expression) indicates that this receptor contributes to the differential regulation of distinct neural circuits. Moreover, the plasticity of expression observed in the large cells implicates this receptor in the behavioral maturation of the bee.
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Affiliation(s)
- Merideth A Humphries
- Department of Biochemistry, University of Queensland, St. Lucia, QLD. 4072 Australia.
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Myeong H, Jeoung D, Kim H, Ha JH, Lee Y, Kim KH, Park C, Kaang BK. Genomic analysis and functional expression of canine dopamine D2 receptor. Gene 2000; 257:99-107. [PMID: 11054572 DOI: 10.1016/s0378-1119(00)00384-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Dopamine D2 receptor (DRD2) is one of the five dopamine receptors with seven transmembrane domains that are coupled to the G protein. We have cloned and characterized the genomic and cDNA sequences of the canine DRD2 gene, which are 12.7 and 2.7 kb in size, respectively. The genomic DNA is composed of seven exons and six introns, encoding a 443 amino acid protein with 95% amino acid identity to other mammalian D2 receptors. A length polymorphism was detected in intron 3 of the receptor gene. We also characterized alternatively spliced forms of DRD2 cDNAs, DRD2L and DRD2S. They showed a higher level of expression in midbrain and thalamus. The ratio between the long and short form is similar in RT-PCR reaction. In human and rodent, the same two spliced forms are known to be coupled to G(i)-type heterotrimeric GTP binding protein, thereby opening an inwardly rectifying potassium channel, GIRK1. When the canine DRD2L and DRD2S were heterologously expressed in Xenopus oocytes, both forms activated GIRK1 potassium channels through coupling with G(i) protein. This activation was dose-dependent, demonstrating its ligand specificity.
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MESH Headings
- Amino Acid Sequence
- Animals
- Blotting, Northern
- Cloning, Molecular
- DNA/chemistry
- DNA/genetics
- DNA/isolation & purification
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- Dogs
- Dopamine/pharmacology
- Dose-Response Relationship, Drug
- Female
- Gene Expression
- Genes/genetics
- Genotype
- Male
- Membrane Potentials/drug effects
- Molecular Sequence Data
- Oocytes
- Pedigree
- Phylogeny
- Polymorphism, Genetic
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Dopamine D2/genetics
- Receptors, Dopamine D2/physiology
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Tissue Distribution
- Xenopus
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Affiliation(s)
- H Myeong
- National Creative Research Initiative Center for Behavioral Genetics, Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 305-701, Taejon, South Korea
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Abstract
Dopamine is an important neurotransmitter involved in motor control, endocrine function, reward, cognition and emotion. Dopamine receptors belong to the superfamily of G protein-coupled receptors and play a crucial role in mediating the diverse effects of dopamine in the central nervous system (CNS). The dopaminergic system is implicated in disorders such as Parkinson's disease and addiction, and is the major target for antipsychotic medication in the treatment of schizophrenia. Molecular cloning studies a decade ago revealed the existence of five different dopamine receptor subtypes in mammalian species. While the presence of the abundantly expressed dopamine D(1) and D(2) receptors was predicted from biochemical and pharmacological work, the cloning of the less abundant dopamine D(3), D(4) and D(5) receptors was not anticipated. The identification of these novel dopamine receptor family members posed a challenge with respect to determining their precise physiological roles and identifying their potential as therapeutic targets for dopamine-related disorders. This review is focused on the accomplishments of one decade of research on the dopamine D(4) receptor. New insights into the biochemistry of the dopamine D(4) receptor include the discovery that this G protein-coupled receptor can directly interact with SH3 domains. At the physiological level, converging evidence from transgenic mouse work and human genetic studies suggests that this receptor has a role in exploratory behavior and as a genetic susceptibility factor for attention deficit hyperactivity disorder.
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Affiliation(s)
- J N Oak
- Laboratory of Molecular Neurobiology, Centre for Addiction and Mental Health, Clarke Div., 250 College street, M5T 1R8, Toronto, Ontario, Canada
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Abstract
In 1952 Delay and Deniker introduced the first antipsychotic, chlorpromazine, into the treatment of mental patients. They subsequently defined the word 'neuroleptic' to describe drugs as different as reserpine and chlorpromazine which seemed to have similar effects on the mental life of patients. In the 1960s the hypothesis was developed, mainly due to Carlsson, that the principal mode of action of neuroleptics was to interfere with synaptic transmission mediated by dopamine (DA) in the brain. This concept was given substantial credence with the discovery by Seeman and Snyder in the 1970s that many of the neuroleptics acted as DA receptor blockers. Subsequently two different classes of DA receptor were defined on the basis of their coupling to adenylate cyclase by Kebabian. In the 1980s molecular biology led to the cloning of five different DA receptors, and at the end of this period vanTol and his colleagues cloned the D4 DA receptor, which has been of considerable interest in the 1990s as it is greatly elevated in the brains of schizophrenics. This historical review ends with a consideration of the possibility that in addition to DA receptors, serotonin and perhaps other transmitter receptors are involved in the aetiology of schizophrenia.
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Affiliation(s)
- M R Bennett
- Institute for Biomedical Research and Department of Physiology, University of Sydney, NSW, Australia.
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Reavill C, Boyfield I, Coldwell M, Nelson P. Comparative pharmacological study of ropinirole (SKF-101468) and its metabolites in rats. J Pharm Pharmacol 2000; 52:1129-35. [PMID: 11045894 DOI: 10.1211/0022357001774895] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
The dopamine receptor agonist ropinirole (SKF-101468) is used to treat Parkinson's disease. Ropinirole is metabolized by two routes to a series of different metabolites although the predominant pathway is species-dependent. It is unknown whether any of the metabolites contribute to its antiparkinsonian activity and whether D3 or D2 receptor agonist activity plays a preferential role. Therefore ropinirole and its primary metabolites, SKF-104557, SKF-97930 and SKF-96990, and the rat metabolite, SKF-89124 were tested in the 6-hydroxydopamine lesion model of Parkinson's disease. SKF-89124 and SKF-96990 were also assayed in radioligand binding and microphysiometer functional assays at cloned human dopamine D2 and D3. Ropinirole and SKF-89124 were equipotent in-vivo, and produced dose-related increases in circling at 0.05-0.8 mg kg(-1), s.c. (ropinirole) and 0.05-0.75 mg kg(-1), s.c. (SKF-89124). Neither SKF-96990 or SKF-97930, at doses up to 15 mg kg(-1), increased the circling rate. Some circling was observed with 15 mg kg(-1) SKF-104557 but the response was less than half that produced by ropinirole (0.8 mgkg(-1)). SKF-104557 was 150-fold less potent than ropinirole. SKF-89124 possessed-30-fold higher affinity for D3 over D2 receptors in radioligand binding studies, but was not selective in the functional microphysiometer assay. SKF-96990 was 10-fold selective for D3 over D2 receptors in the radioligand binding assay. Ropinirole and SKF-104557 are 20-fold selective for D3 over D2 receptors in radioligand binding assays whereas in microphysiometry, selectivity is 10-fold. SKF-97930 is inactive in radioligand binding and microphysiometer assays. Primary metabolites of ropinirole did not contribute significantly to its activity in this model of Parkinson's disease. The lack of dopamine D3/D2 receptor selectivity for ropinirole rules out the possibility of attributing the degree of either D2 or D3 receptor activity to the behavioural efficacy of ropinirole.
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Affiliation(s)
- C Reavill
- SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Harlow, Essex, UK
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Coldwell MC, Boyfield I, Brown T, Hagan JJ, Middlemiss DN. Comparison of the functional potencies of ropinirole and other dopamine receptor agonists at human D2(long), D3 and D4.4 receptors expressed in Chinese hamster ovary cells. Br J Pharmacol 1999; 127:1696-702. [PMID: 10455328 PMCID: PMC1566138 DOI: 10.1038/sj.bjp.0702673] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
1. The aim of the present study was to characterize functional responses to ropinirole, its major metabolites in man (SKF-104557 (4-[2-(propylamino)ethyl]-2-(3H) indolone), SKF-97930 (4-carboxy-2-(3H) indolone)) and other dopamine receptor agonists at human dopamine D2(long) (hD2), D3 (hD3) and D4.4 (hD4) receptors separately expressed in Chinese hamster ovary cells using microphysiometry. 2. All the receptor agonists tested (ropinirole, SKF-104557, SKF-97930, bromocriptine, lisuride, pergolide, pramipexole, talipexole, dopamine) increased extracellular acidification rate in Chinese hamster ovary clones expressing the human D2, D3 or D4 receptor. The pEC50s of ropinirole at hD2, hD3 and hD4 receptors were 7.4, 8.4 and 6.8, respectively. Ropinirole is therefore at least 10 fold selective for the human dopamine D3 receptor over the other D2 receptor family members. 3. At the hD2 and hD3 dopamine receptors all the compounds tested were full agonists as compared to quinpirole. Talipexole and the ropinirole metabolite, SKF-104557, were partial agonists at the hD4 receptor. 4. Bromocriptine and lisuride had a slow onset of agonist action which precluded determination of EC50s. 5. The rank order of agonist potencies was dissimilar to the rank order of radioligand binding affinities at each of the dopamine receptor subtypes. Functional selectivities of the dopamine receptor agonists, as measured in the microphysiometer, were less than radioligand binding selectivities. 6. The results show that ropinirole is a full agonist at human D2, D3 and D4 dopamine receptors. SKF-104557 the major human metabolite of ropinirole, had similar radioligand binding affinities to, but lower functional potencies than, the parent compound.
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Affiliation(s)
- Martyn C Coldwell
- Neurosciences Research, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Harlow, Essex CM19 5AW
| | - Izzy Boyfield
- Neurosciences Research, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Harlow, Essex CM19 5AW
| | - Tony Brown
- Neurosciences Research, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Harlow, Essex CM19 5AW
| | - Jim J Hagan
- Neurosciences Research, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Harlow, Essex CM19 5AW
| | - Derek N Middlemiss
- Neurosciences Research, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Harlow, Essex CM19 5AW
- Author for correspondence:
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Coldwell MC, Boyfield I, Brown AM, Stemp G, Middlemiss DN. Pharmacological characterization of extracellular acidification rate responses in human D2(long), D3 and D4.4 receptors expressed in Chinese hamster ovary cells. Br J Pharmacol 1999; 127:1135-44. [PMID: 10455259 PMCID: PMC1566129 DOI: 10.1038/sj.bjp.0702657] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
This study characterized pharmacologically the functional responses to agonists at human dopamine D2(long) (hD2), D3 (hD3) and D4.4 (hD4) receptors separately expressed in cloned cells using the cytosensor microphysiometer. Dopaminergic receptor agonists caused increases in extracellular acidification rate in adherent Chinese hamster ovary (CHO) clones expressing hD2, hD3 or hD4 receptors. Acidification rate responses to agonists in other cell lines expressing these receptors were smaller than those in adherent CHO cells. The time courses and maximum increases in acidification rate of the agonist responses in adherent CHO cells were different between the three dopamine receptor clones. Responses were blocked by pretreatment of cells with pertussis toxin or amiloride analogues. Most agonists had full intrinsic activity at each of the dopamine receptor subtypes, as compared to quinpirole, however both enantiomers of UH-232 and (-)3-PPP were partial agonists in this assay system. The functional potency of full agonists at each of the three receptors expressed in CHO cells was either higher than, or similar to, the apparent inhibition constants (Ki) determined in [125I]-iodosulpride competition binding studies. Functional selectivities of the agonists were less than radioligand binding selectivities. The rank orders of agonist potencies and selectivities were similar, but not identical, to the rank orders of radioligand binding affinities and selectivities. The dopamine receptor antagonists, iodosulpride and clozapine, had no effect on basal acidification rates but inhibited acidification responses in CHO cells to quinpirole in an apparently competitive manner. Antagonist potencies closely matched their radioligand binding affinities in these cells.
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Affiliation(s)
- M C Coldwell
- Neuroscience Research, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Harlow, Essex CM19 5AW
| | - I Boyfield
- Neuroscience Research, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Harlow, Essex CM19 5AW
| | - A M Brown
- Neuroscience Research, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Harlow, Essex CM19 5AW
| | - G Stemp
- Medicinal Chemistry, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Harlow, Essex CM19 5AW
| | - D N Middlemiss
- Neuroscience Research, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Harlow, Essex CM19 5AW
- Author for correspondence:
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17
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Djamgoz MB, Hankins MW, Hirano J, Archer SN. Neurobiology of retinal dopamine in relation to degenerative states of the tissue. Vision Res 1997; 37:3509-29. [PMID: 9425527 DOI: 10.1016/s0042-6989(97)00129-6] [Citation(s) in RCA: 199] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Neurobiology of retinal dopamine is reviewed and discussed in relation to degenerative states of the tissue. The Introduction deals with the basic physiological actions of dopamine on the different neurons in vertebrate retinae with an emphasis upon mammals. The intimate relationship between the dopamine and melatonin systems is also covered. Recent advances in the molecular biology of dopamine receptors is reviewed in some detail. As degenerative states of the retina, three examples are highlighted: Parkinson's disease; ageing; and retinal dystrophy (retinitis pigmentosa). As visual functions controlled, at least in part, by dopamine, absolute sensitivity, spatial contrast sensitivity, temporal (including flicker) sensitivity and colour vision are reviewed. Possible cellular and synaptic bases of the visual dysfunctions observed during retinal degenerations are discussed in relation to dopaminergic control. It is concluded that impairment of the dopamine system during retinal degenerations could give rise to many of the visual abnormalities observed. In particular, the involvement of dopamine in controlling the coupling of horizontal and amacrine cell lateral systems appears to be central to the visual defects seen.
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Affiliation(s)
- M B Djamgoz
- Department of Biology, Imperial College of Science, Technology and Medicine, London, U.K.
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18
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Wanderoy MH, Westlind-Danielsson A. Molecular mechanisms underlying forskolin-mediated up-regulation of human dopamine D2L receptors. Cell Mol Neurobiol 1997; 17:547-55. [PMID: 9353595 DOI: 10.1023/a:1026367023458] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
1. Human dopamine (DA) D2long (hD2L) receptors, expressed by Ltk- cells, can be up-regulated by treating the cells with forskolin for 16 hr (Johansson and Westlind-Danielsson, 1994). We have examined some of the molecular mechanisms underlying this forskolin-mediated up-regulation. 2. Forskolin (100 microM, 16 hr), but not 1,9-dideoxyforskolin, a forskolin analogue that is unable to activate adenylyl cyclase and raise intracellular cAMP concentrations, up-regulates the hD2L receptor population by 43%. The implication of a cAMP-dependent increase in the receptor up-regulation was further substantiated by treating the cells with 8-bromo-cAMP or prostaglandin E1 (PGE1). The forskolin-mediated rise in receptor number was blocked by cycloheximide or an antisense phosphorothioate oligodeoxynucleotide (ODN) directed toward the hD2L mRNA. KT5720, a specific protein kinase A (PKA) inhibitor, completely blocked the receptor rise, whereas pertussis toxin (PTX) attenuated the increase considerably. Forskolin also produced an increase in the level of the DA hD2short (hD2S) receptor expressed by Ltk- cells. This increase was 2.5-fold higher than that found for the hD2L receptor. 3. The forskolin-mediated hD2L receptor rise is dependent on de novo protein synthesis, a rise in cAMP levels, PKA activation, and, at least partially, PTX-sensitive G proteins. 4. Long-term increases in intracellular cAMP levels may change the sensitivity of a DA receptor expressing cell to DA by increasing D2 receptor density through enhanced cAMP-dependent transcription.
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Affiliation(s)
- M H Wanderoy
- Department of Biochemistry, CNS Preclinical R&D, Astra Arcus AB, Södertälje, Sweden
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19
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Josselyn SA, Miller R, Beninger RJ. Behavioral effects of clozapine and dopamine receptor subtypes. Neurosci Biobehav Rev 1997; 21:531-58. [PMID: 9353791 DOI: 10.1016/s0149-7634(96)00051-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The atypical neuroleptic clozapine (CLZ) is an extremely effective antipsychotic that produces relatively few motoric side effects. However, CLZ displays limited antagonism at the dopamine (DA) D2 receptor, the receptor commonly thought to mediate the antipsychotic activity of neuroleptics. The mechanism of action behind the efficacy of CLZ remains to be determined. Miller, Wickens and Beninger [Progr. Neurobiol., 34, 143-184 (1990)] propose a "D1 hypothesis of antipsychotic action" that may explain the antipsychotic effects of CLZ. This hypothesis is built on the interactions between D2, cholinergic and D1 mechanisms in the striatum. These authors assert that although typical neuroleptics block D2 receptors, it is through an indirect action on D1 receptors that their antipsychotic action is manifest. The extra-pyramidal side effects produced by typical neuroleptics are hypothesized to be due to an indirect action on cholinergic receptors. It is argued that the anticholinergic properties of CLZ negate the D2 (motor side effects) action of CLZ, allowing CLZ to diminish psychotic symptoms through a direct action on D1 receptors. Thus, CLZ may function as a D1 receptor antagonist in behavioral paradigms. The current paper reviews and compares the behavioral profile of CLZ to those produced by D2- and D1-selective antagonists with specific reference to unconditioned and conditioned behaviors in order to more fully evaluate the "D1 hypothesis of CLZ action". Although the actions of CLZ remain unique, they do share some striking similarities with D1 receptor antagonists especially in tests of unconditioned behavior, possibly implicating the D1 receptor in the action of this antipsychotic drug.
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Affiliation(s)
- S A Josselyn
- Department of Psychology, University of Toronto, Ontario, Canada
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20
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Lachowicz JE, Sibley DR. Molecular characteristics of mammalian dopamine receptors. PHARMACOLOGY & TOXICOLOGY 1997; 81:105-13. [PMID: 9335067 DOI: 10.1111/j.1600-0773.1997.tb00039.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Dopamine receptors belong to a large super-gene family of receptors which are linked to their signal transduction pathways through heterotrimeric G proteins. A variety of signalling events are known to be regulated by dopamine receptors including adenylate cyclase and phospholipase activities and various ion channels. Prior to the advent of molecular cloning technology, dopamine receptors were believed to belong to two subtypes, D1 and D2. This distinction was based on both pharmacological and functional criteria. We now know that at least five different dopamine receptors exist although they can still be described as to belonging within "D1" and "D2" subfamilies. The D1 subfamily consists of two receptors-the D1 and D5, whereas the D2, D3 and D4 receptors comprise the D2 subfamily. The cloning and molecular characteristics of these five receptors are described in this review.
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MESH Headings
- Adenylyl Cyclases/metabolism
- Amino Acid Sequence
- Animals
- Cloning, Molecular
- Dopamine Agonists/pharmacology
- Dopamine Antagonists/pharmacology
- Gene Expression Regulation/genetics
- Humans
- Ion Channels/metabolism
- Molecular Sequence Data
- Phospholipases/metabolism
- Receptors, Dopamine/biosynthesis
- Receptors, Dopamine/drug effects
- Receptors, Dopamine/genetics
- Receptors, Dopamine D1/drug effects
- Receptors, Dopamine D1/genetics
- Receptors, Dopamine D1/metabolism
- Receptors, Dopamine D2/drug effects
- Receptors, Dopamine D2/genetics
- Receptors, Dopamine D2/metabolism
- Receptors, Dopamine D3
- Receptors, Dopamine D4
- Receptors, Dopamine D5
- Signal Transduction/genetics
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Affiliation(s)
- J E Lachowicz
- Department of Pediatrics, Indiana University, School of Medicine, Indianapolis, USA
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21
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Wang S, He C, Maguire MT, Clemmons AL, Burrier RE, Guzzi MF, Strader CD, Parker EM, Bayne ML. Genomic organization and functional characterization of the mouse GalR1 galanin receptor. FEBS Lett 1997; 411:225-30. [PMID: 9271210 DOI: 10.1016/s0014-5793(97)00695-9] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Galanin mediates diverse physiological functions in digestive, endocrine, and central nervous systems through G-protein-coupled receptors. Two galanin receptors have been cloned but the gene structures are unknown. We report genomic and cDNA cloning of the mouse GalR1 galanin receptor and demonstrate that the coding sequence is uniquely divided into three exons encoding the N-terminal portion through the fifth transmebrane domain, the third intracellular loop, and the sixth transmembrane domain through the C-terminus. Functional analysis of the encoded cDNA revealed active ligand binding and intracellular signaling. The expression is detected in brain, spinal cord, heart and skeletal muscle.
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MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Binding, Competitive
- Central Nervous System/chemistry
- Cloning, Molecular
- Colforsin/antagonists & inhibitors
- Colforsin/pharmacology
- Cyclic AMP/metabolism
- Exons/genetics
- Humans
- Introns/genetics
- Mice
- Molecular Sequence Data
- Molecular Weight
- Muscle, Skeletal/chemistry
- Myocardium/chemistry
- RNA, Messenger/analysis
- Rats
- Receptors, Galanin
- Receptors, Gastrointestinal Hormone/chemistry
- Receptors, Gastrointestinal Hormone/genetics
- Receptors, Gastrointestinal Hormone/metabolism
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
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Affiliation(s)
- S Wang
- Department of CNS/CV Biological Research, Schering-Plough Research Institute, Kenilworth, NJ 07033, USA.
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22
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Pohjalainen T, Cravchik A, Gejman PV, Rinne J, Någren K, Syvälahti E, Hietala J. Antagonist binding characteristics of the Ser311-->Cys variant of human dopamine D2 receptor in vivo and in vitro. Biochem Biophys Res Commun 1997; 232:143-6. [PMID: 9125119 DOI: 10.1006/bbrc.1997.6123] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We report in vivo and in vitro antagonist binding characteristics of the naturally occurring Ser311-->Cys variant of the human D2 dopamine receptor. Striatal receptor binding characteristics in vivo were measured with positron emission tomography and the D2 antagonist [11C]raclopride. The in vitro affinity of raclopride for the Ser311-->Cys variant and the wild type receptor was studied in membrane binding assays from stably transfected cell lines. One healthy male carrying the heterozygous Ser311-->Cys (TCC-->TGC) substitution was identified with denaturing gradient gel electrophoresis and DNA sequencing. The striatal D2 receptor binding characteristics in vivo in this subject were normal. This was supported by the in vitro data as the Ki values of raclopride for the Ser311-->Cys variant and the wild type receptor were identical. Our data suggest that the Ser311-->Cys variant of the human D2 receptor does not influence antagonist-receptor recognition in vivo or in vitro.
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Affiliation(s)
- T Pohjalainen
- Department of Pharmacology and Clinical Pharmacology, University of Turku, Finland
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23
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Griffon N, Crocq MA, Pilon C, Martres MP, Mayerova A, Uyanik G, Burgert E, Duval F, Macher JP, Javoy-Agid F, Tamminga CA, Schwartz JC, Sokoloff P. Dopamine D3 receptor gene: organization, transcript variants, and polymorphism associated with schizophrenia. AMERICAN JOURNAL OF MEDICAL GENETICS 1996; 67:63-70. [PMID: 8678117 DOI: 10.1002/(sici)1096-8628(19960216)67:1<63::aid-ajmg11>3.0.co;2-n] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
DNA fragments from a genomic library were used to establish the partial structure of the human dopamine D3 receptor gene (DRD3). Its coding sequence contains 6 exons and stretches over 40,000 base pairs. The complete DRD3 transcript and three shorter variants, in which the second and/or third exon are deleted, were detected in similar proportions in brains from four controls and three psychiatric patients. The Msp I polymorphism was localized in the fifth intron of the gene, 40,000 base pairs downstream the Bal I polymorphism and a PCR-based method was developed for genotyping this polymorphism. The distribution of the Msp I and Bal I genotypes were not independent in 297 individuals (chi 2 = 10.5, df = 4, P = 0.03), but only a weak association was found between allele 1 of the Bal I polymorphism and allele 2 of the Msp I polymorphism (chi 2 = 3.99, df = 1, P = 0.04). The previously reported association between homozygosity at both alleles of the Bal I polymorphism and schizophrenia was presently maintained in an extended sample, comprising 119 DSM-III-R chronic schizophrenics and 85 controls (chi 2 = 5.3, df = 1, P = 0.02) and found more important in mal than in females. The presence of the Bal I allele 2 is associated with an early age at onset, particularly in males (df = 35, t value = 2.6, P = 0.014). In the same sample, allelic frequencies, genotype counts, and proportion of homozygotes for the Msp I polymorphism did not differ between schizophrenics and controls (chi 2 = 0.06, df = 1, P = 0.80, chi 2 = 0.22, df = 1, P = 0.90 and chi 2 = 0.16, df = 1, P = 0.69, respectively). The large distance of the Msp I polymorphism from the Bal I polymorphism and its localization in the 3' part of the gene may explain the discrepant results obtained with the two polymorphisms.
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Affiliation(s)
- N Griffon
- Unité de Neurobiologie et Pharmacologie, Centre Paul Broca l'INSERM, Paris, France
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24
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Autelitano DJ, van den Buuse M. Altered expression of dopamine D2 receptor mRNA splice variants in brain and pituitary of spontaneously hypertensive rats. Neurosci Lett 1995; 195:1-4. [PMID: 7478242 DOI: 10.1016/0304-3940(95)11756-m] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Both central and peripheral dopamine (DA) has been shown to play a role in the regulation of blood pressure. Using sensitive nuclease protection analysis, we have compared the expression of DA D-2 receptor (D2-R) mRNA splice variants in brain and pituitary of spontaneously hypertensive rats (SHR) with normotensive Wistar-Kyoto (WKY) controls. Levels of D2-R mRNA were significantly altered in pituitary anterior lobe (AL) and neurointermediate lobe (NIL), and in striatum of SHR, but not in any other brain regions examined. SHR pituitary expressed 50-80% higher levels of D2-R mRNA, coupled with an increase in the relative proportion of the long (D2-L) mRNA variant. In contrast, overall D2-R mRNA expression in SHR striatum was only 75% that of WKY controls, however, the relative proportion of the D2-L splice variant was increased. The present data demonstrate that tissue specific alterations in D2-R mRNA levels and primary transcript splicing exist in the SHR and suggest that these changes may in part mediate differential responsiveness to DA that may be related to the development of hypertension.
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Affiliation(s)
- D J Autelitano
- Molecular Physiology Laboratory, Baker Medical Research Institute, Prahran, Victoria, Australia
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25
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Sibley DR, Monsma FJ, McVittie LD, Gerfen CR, Burch RM, Mahan LC. Molecular neurobiology of dopamine receptor subtypes. Neurochem Int 1995; 20 Suppl:17S-22S. [PMID: 1365419 DOI: 10.1016/0197-0186(92)90205-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- D R Sibley
- Experimental Therapeutics Branch, NINDS, National Institutes of Health, Bethesda, MD 20892
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26
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Stamm S, Zhang MQ, Marr TG, Helfman DM. A sequence compilation and comparison of exons that are alternatively spliced in neurons. Nucleic Acids Res 1994; 22:1515-26. [PMID: 8202349 PMCID: PMC308024 DOI: 10.1093/nar/22.9.1515] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Alternative splicing is an important regulatory mechanism to create protein diversity. In order to elucidate possible regulatory elements common to neuron specific exons, we created and statistically analysed a database of exons that are alternatively spliced in neurons. The splice site comparison of alternatively and constitutively spliced exons reveals that some, but not all alternatively spliced exons have splice sites deviating from the consensus sequence, implying diverse patterns of regulation. The deviation from the consensus is most evident at the -3 position of the 3' splice site and the +4 and -3 position of the 5' splice site. The nucleotide composition of alternatively and constitutively spliced exons is different, with alternatively spliced exons being more AU rich. We performed overlapping k-tuple analysis to identify common motifs. We found that alternatively and constitutively spliced exons differ in the frequency of several trinucleotides that cannot be explained by the amino acid composition and may be important for splicing regulation.
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Affiliation(s)
- S Stamm
- Cold Spring Harbor Laboratory, NY 11724
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27
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Valdenaire O, Vernier P, Maus M, Dumas Milne Edwards JB, Mallet J. Transcription of the rat dopamine-D2-receptor gene from two promoters. EUROPEAN JOURNAL OF BIOCHEMISTRY 1994; 220:577-84. [PMID: 8125117 DOI: 10.1111/j.1432-1033.1994.tb18658.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Modulation of the expression of the D2-dopamine receptor gene is involved in several pathological and developmental circumstances. The gene and the corresponding promoter regions of the rat D2 receptor were isolated and partly characterized to study its regulation. The rat D2-receptor gene spans at least 50 kb, and possesses eight exons; its organization was compared to those of the other dopamine-receptor genes in a phylogenetic perspective. The gene contains two transcription-start sites: the major one is located about 320 bp upstream from the 3' end of the first exon, and a minor site is 70 bp further upstream. Transient-expression assays with fusion constructs comprising fragments of the D2-promoter region and the luciferase reporter gene confirmed the existence of two independent, TATA-lacking promoters. Both promoters separately induced transcription of the luciferase gene in C6 glioma, primary fibroblasts, GH3 and MMQ pituitary cell lines, among which only the MMQ cells normally express the D2 receptor. Transcription is enhanced by the reunion of the two promoters, and modified by the addition of upstream sequences. Thus the 1-kb promoter region analysed does not contain all the elements necessary to confer tissue-specific expression of the gene, but does carry some positive and negative regulatory elements, which remain to be characterized.
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Affiliation(s)
- O Valdenaire
- Laboratoire de Génétique Moléculaire de la Neurotransmission et des Processus Neurodégénératifs, UMR C9923, Gif-sur-Yvette, France
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28
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Jackson DM, Westlind-Danielsson A. Dopamine receptors: molecular biology, biochemistry and behavioural aspects. Pharmacol Ther 1994; 64:291-370. [PMID: 7878079 DOI: 10.1016/0163-7258(94)90041-8] [Citation(s) in RCA: 317] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The description of new dopamine (DA) receptor subtypes, D1-(D1 and D5) and D2-like (D2A, D2B, D3, D4), has given an impetus to DA research. While selective agonists and antagonists are not generally available yet, the receptor distribution in the brain suggests that they could be new targets for drug development. Binding characteristics and second messenger coupling has been explored in cell lines expressing the new cloned receptors. The absence of selective ligands has meant that in vivo studies have lagged behind. However, progress has been made in understanding the function of DA-containing discrete brain nuclei and the functional consequence of the DA's interaction with other neurotransmitters. This review explores some of the latest advances in these various areas.
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Affiliation(s)
- D M Jackson
- Department of Behavioural, Pharmacology, Astra Arcus AB, Södertälje, Sweden
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29
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Rappaport MS, Sealfon SC, Prikhozhan A, Huntley GW, Morrison JH. Heterogeneous distribution of D1, D2 and D5 receptor mRNAs in monkey striatum. Brain Res 1993; 616:242-50. [PMID: 8358616 DOI: 10.1016/0006-8993(93)90215-9] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The primate striatum has a compartmental organization reflected both in the topography of its afferent projections and in the segregation of its morphologically similar but neurochemically distinct efferent neurons. Discretely projecting mesostriatal neurons release dopamine (DA) which modulates the responses of striatal neurons to other afferent inputs. Multiple DA receptor (DAR) subtypes have been cloned and characterized and mapping their cellular expression is crucial for understanding the influence of DA on striatal function. We report the distribution of mRNAs for D1, D2 and D5 DAR subtypes (D2R, D2R and D5R) in the striatum of cynomolgus monkeys (Macaca fascicularis) studied by in situ hybridization histochemistry (ISH) using monkey-specific cRNA probes. Adjacent sections were stained for calbindin immunoreactivity to distinguish striosomal and matrix compartments for comparison with the patterns obtained with ISH. In the caudate nucleus, D1R mRNA was concentrated in calbindin-poor striosomes where dense grain clusters were seen overlying the majority of medium-sized neurons (diameter approximately 15 microns). D1R mRNA localization was relatively homogeneous in the putamen. By contrast, the distributions of D2R and D5R mRNAs showed no clear preference for the striosomal or matrix compartments of either caudate nucleus or putamen. In the ventral striatum (nucleus accumbens, olfactory tubercle and ventral portions of caudate nucleus and putamen), expression of D1R and D2R mRNA was sparse relative to dorsal striatum, while D5R mRNA expression was roughly equal in ventral and dorsal striatum. Circumscribed zones of hybridization associated with islands of tightly packed small cells occurred with all three DAR mRNA subtypes in the ventral striatum.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- M S Rappaport
- Fishberg Research Center for Neurobiology, Mount Sinai School of Medicine, New York, NY 10029-6574
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30
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Herzog H, Hort YJ, Shine J, Selbie LA. Molecular cloning, characterization, and localization of the human homolog to the reported bovine NPY Y3 receptor: lack of NPY binding and activation. DNA Cell Biol 1993; 12:465-71. [PMID: 8329116 DOI: 10.1089/dna.1993.12.465] [Citation(s) in RCA: 90] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
A cDNA clone encoding the human homolog of the bovine cDNA clone LCR1 was isolated from a human lung cDNA library. The 1,670-bp-long nucleotide sequence predicts a single open reading frame of 352 amino acids, with a 92% amino acid identity to a bovine sequence reported to represent the neuropeptide Y (NPY) Y3 receptor. The amino acid sequence shares features common to many other G-protein-coupled receptors, including the seven transmembrane regions and putative glycosylation and phosphorylation sites. Polymerase chain reaction (PCR) analysis of human-hamster hybrid cell DNA reveals that the corresponding gene is located on human chromosome 2. Although the ligand for the bovine receptor has previously been identified as NPY in binding studies, extensive analysis with the human homolog transfected in several different cell lines failed to confirm this classification. Furthermore, the receptor shows 36% identity to both the human interleukin-8 (IL-8) and angiotensin II receptors but only 21% identity to the human NPY Y1 receptor. In addition, NPY and a number of other ligands fail to induce any change in cytosolic calcium levels in transfected cells, suggesting that this clone represents a novel neuropeptide receptor.
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Affiliation(s)
- H Herzog
- Garvan Institute of Medical Research, St. Vincent's Hospital, Sydney, NSW, Australia
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31
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Merchant KM, Dobie DJ, Dorsa DM. Differential loss of dopamine D2 receptor mRNA isoforms during aging in Fischer-344 rats. Neurosci Lett 1993; 154:163-7. [PMID: 8361633 DOI: 10.1016/0304-3940(93)90197-s] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Effects of aging on the expression of dopamine D2 receptor isoforms (D2-long and -short) in neostriatal subregions was examined by in situ hybridization histochemistry. Hybridization of a probe selective for the D2-long transcript was compared with signal generated by a probe recognizing both variants of D2 mRNA. Lateral quadrants of the neostriatum in old rats appeared to show declines in primarily the long transcripts. On the other hand, decreases in the expression of D2-short transcripts appeared to occur during aging in the ventromedial region of the striatum. These data suggest that the mechanisms involved in alternative splicing of D2 mRNA may be differentially altered in neostriatal subregions during aging.
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Affiliation(s)
- K M Merchant
- Geriatric Research, Education and Clinical Center, Seattle Veterans Administration Medical Center, WA 98108
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32
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Affiliation(s)
- B F O'Dowd
- Addiction Research Foundation, University of Toronto, Ontario, Canada
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33
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Sibley DR, Monsma FJ, Shen Y. Molecular neurobiology of dopaminergic receptors. INTERNATIONAL REVIEW OF NEUROBIOLOGY 1993; 35:391-415. [PMID: 8463063 DOI: 10.1016/s0074-7742(08)60573-5] [Citation(s) in RCA: 182] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Table I summarizes the properties of all of the dopamine receptors that have been cloned to date. Thus far, five different genes encoding pharmacologically distinct receptors have been identified and isolated. Based on their structural, pharmacological, and functional similarities, two of these, D1A and D1B (or D1 and D5), comprise the D1 subfamily. D2, D3, and D4 receptors represent a D2 subfamily whose members are also structurally and pharmacologically similar. In fact, given these considerations, it has been suggested that the D2, D3, and D4 receptors be termed the D2A, D2B, and D2C receptors, respectively, in recognition of their D2-like properties. Given the unexpected heterogeneity of the dopaminergic receptor system, it is logical to ask if there are other dopamine receptor subtypes remaining be identified. This seems probable, as the characteristics of the cloned subtypes do not match all of the properties of some dopamine receptors which have been previously investigated. For instance, there is extensive evidence that "D1-like" dopamine receptors exist which are linked to the activation of phospholipase C, phosphatidylinositol turnover, and Ca2+ mobilization. Dopamine, as well as several "D1-selective" agonists, has been shown to stimulate phosphatidylinositol turnover in both brain slices and kidney membranes (Felder et al., 1989; Undie and Friedman, 1990; Vyas et al., 1992), and injection of striatal mRNA into Xenopus oocytes leads to dopamine-stimulated phosphatidylinositol turnover and Ca2+ mobilization (Mahan et al., 1990). These dopamine receptors might be analogous to the alpha 1-adrenergic receptors which stimulate phospholipase C activity and might define a third distinct subfamily of dopamine receptors. There is also evidence for additional members of the D2 subfamily of receptors. Using gene transfer methods, a receptor with D2-like pharmacology has been identified and expressed but not yet sequenced (Todd et al., 1989). Also, a D2-related receptor has been characterized in kidney inner medulla membranes (Huo et al., 1991). It thus appears that there may be more dopamine receptor subtypes yet to be discovered.
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Affiliation(s)
- D R Sibley
- Molecular Neuropharmacology Section, National Institute of Neurological Disorders and Stroke National Institutes of Health, Bethesda, Maryland 20892
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34
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Leysen JE, Gommeren W, Mertens J, Luyten WH, Pauwels PJ, Ewert M, Seeburg P. Comparison of in vitro binding properties of a series of dopamine antagonists and agonists for cloned human dopamine D2S and D2L receptors and for D2 receptors in rat striatal and mesolimbic tissues, using [125I] 2'-iodospiperone. Psychopharmacology (Berl) 1993; 110:27-36. [PMID: 7870895 DOI: 10.1007/bf02246947] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We investigated the ligand binding properties in vitro of two splice variants of the cloned human dopamine D2 receptor (the 443 and 414 amino acids long forms called D2L and D2S, respectively), expressed in 293 human kidney cells, in comparison with those of the dopamine D2 receptors in rat striatum, nucleus accumbens and tuberculum olfactorium. The new radioligand, [125I]2'-iodospiperone, showed a similar high binding affinity (KD:0.056-0.122 nM) for cloned human D2S and D2L receptors and for the D2 receptors in the three rat brain areas. Binding affinities of 25 dopamine antagonists and of 10 dopamine agonists belonging to different chemical classes were measured. The IC50 values of the antagonists were virtually identical in the five preparations: spiperone was the most potent compound (pIC50 approximately 9.9), remoxipride the least potent one (pIC50 approximately 5.7). The agonists showed similar IC50 values for the cloned human D2S and D2L receptors but their affinity for rat brain D2 receptors was 2- to 5-fold higher. Dopamine showed shallow inhibition curves, the high affinity binding was 10-fold lower for the cloned human D2 receptors than for the rat brain D2 receptors. Addition of stable guanosine-5'-triphosphate (GTP) analogues shifted the D2 receptors in the rat brain tissues to the "low" affinity state, the low affinity binding of dopamine was equal to the affinity for the cloned human receptor. None of the dopamine antagonists or agonists could differentiate between the two splice forms of the cloned human D2 receptors or between the D2 receptors in rat striatal and mesolimbic tissues. The lower apparent affinity of some agonists and of dopamine in the absence of stable GTP analogues suggests a less appropriate receptor G-protein coupling for the cloned human D2 receptors expressed in the 293 human kidney cells. Unexpectedly, guanosine-5'-O-(3-thiotriphosphate) (GTP-gamma-S) reduced the [125I]2'-iodospiperone binding to the D2 receptors by 20-35% in the rat brain tissues and the cloned human D2L receptor, and by 75% to the cloned human D2S receptor. The inhibition in the last case could be prevented partly by submicromolar concentrations of dopamine. The GTP-gamma-S effect is suggested to be due to reduction of disulphide bonds in the receptor. Recent molecular modelling studies indicated an important role of the disulphide bridge between Cys107 at the start of transmembrane domain three and Cys182 in the third extracellular loop, for the binding of dopamine to the D2 receptor.
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Affiliation(s)
- J E Leysen
- Department of Biochemical Pharmacology, Janssen Research Foundation, Beerse, Belgium
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35
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Vadasz C, Laszlovszky I, De Simone PA, Fleischer A. Genetic aspects of dopamine receptor binding in the mouse and rat brain: an overview. J Neurochem 1992; 59:793-808. [PMID: 1494909 DOI: 10.1111/j.1471-4159.1992.tb08317.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- C Vadasz
- Laboratory of Neurobehavioral Genetics, Nathan S. Kline Institute, Orangeburg, New York 10962
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36
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Grandy DK, Allen LJ, Zhang Y, Magenis RE, Civelli O. Chromosomal localization of three human D5 dopamine receptor genes. Genomics 1992; 13:968-73. [PMID: 1387108 DOI: 10.1016/0888-7543(92)90009-h] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
It is currently thought that genetic predisposition to imbalances in dopaminergic transmission may underlie several neurological disorders, including schizophrenia, manic depression, Tourette syndrome, Parkinson disease, Huntington disease, and alcohol abuse. Originally two receptors, D1 and D2, were thought to account for all of the pharmacological actions of dopamine. However, through homology screening three additional genes, D3, D4, and D5, and two pseudogenes closely related to D5 have been characterized. To begin our genomic and evolutionary analyses of the human D5 dopamine receptor gene and its two pseudogenes, we have mapped each of them to their respective chromosomes. By combining in situ hybridization results with sequence analysis of PCR products from microdissected chromosomes, somatic cell hybrids, and radiation hybrids, we have assigned DRD5 (the locus containing the functional human D5 receptor gene) to chromosome 4p16.1, DRD5P1 (the locus containing D5 pseudogene 1) to chromosome 2p11.1-p11.2, and DRD5P2 (the locus of D5 pseudogene 2) to chromosome 1q21.1.
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MESH Headings
- Base Sequence
- Blotting, Southern
- Chromosome Mapping
- Chromosomes, Human, Pair 1
- Chromosomes, Human, Pair 2
- DNA
- Genome, Human
- Humans
- Huntington Disease/genetics
- Karyotyping
- Molecular Sequence Data
- Nucleic Acid Hybridization
- Polymerase Chain Reaction
- Pseudogenes
- Receptors, Dopamine/genetics
- Receptors, Dopamine D1
- Receptors, Dopamine D5
- Templates, Genetic
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Affiliation(s)
- D K Grandy
- Vollum Institute for Advanced Biomedical Research, Oregon Health Sciences University, Portland 97201
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37
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Abstract
This review summarized a part of our studies over a long period of time, relating them to the literature on the same topics. We aimed our research toward an understanding of the genetic origin of brain specific proteins, identified by B. W. Moore and of the high complexity of the nucleotide sequence of brain mRNA, originally investigated by W. E. Hahn, but have not completely achieved the projected goal. According to our studies, the reason for the high complexity in the RNA of brain nuclei might be the high complexity in neuronal nuclear RNA as described in the Introduction. Although one possible explanation is that it results from the summation of RNA complexities of several neuronal types, our saturation hybridization study with RNA from the isolated nuclei of granule cells showed an equally high sequence complexity as that of brain. It is likely that this type of neuron also contains numerous rare proteins and peptides, perhaps as many as 20,000 species which were not detectable even by two-dimensional PAGE. I was possible to gain insight into the reasons for the high sequence complexity of brain RNA by cloning the cDNA and genomic DNA of the brain-specific proteins as described in the previous sections. These data provided evidence for the long 3'-noncoding regions in the cDNA of the brain-specific proteins which caused the mRNA of brain to be larger than that from other tissues. During isolation of such large mRNAs, a molecule might be split into a 3'-poly(A)+RNA and 5'-poly(A)-RNA. In the studies on genomic DNA, genes with multiple transcription initiation sites were found in brain, such as CCK, CNP and MAG, in addition to NSE which was a housekeeping gene, and this may contribute to the high sequence complexity of brain RNA. Our studies also indicated the presence of genes with alternative splicing in brain, such as those for CNP, MAG and NGF, suggesting a further basis for greater RNA nucleotide sequence complexity. It is noteworthy that alternative splicing of the genes for MBP and PLP also produced multiple mRNAs. Such a mechanism may be a general characteristic of the genes for the myelin-specific proteins produced by oligodendrocytes. In considering the high nucleotide sequence complexity, it is interesting that MAG and S-100 beta genes etc. possess two additional sites for poly(A).(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- Y Takahashi
- Department of Neuropharmacology, Niigata University, Japan
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38
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Selbie LA, Townsend-Nicholson A, Iismaa TP, Shine J. Novel G protein-coupled receptors: a gene family of putative human olfactory receptor sequences. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1992; 13:159-63. [PMID: 1315913 DOI: 10.1016/0169-328x(92)90057-i] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We have taken advantage of the sequence conservation in the G protein-coupled receptor superfamily to isolate a fragment of a novel G protein-coupled receptor sequence using polymerase chain reaction (PCR) amplification of human genomic DNA. Screening of human genomic and hippocampal cDNA libraries with this amplified receptor fragment revealed a number of related sequences. Sequence analysis of four genomic clones and one cDNA clone clearly identifies these as related members of the G protein-coupled receptor family, as the deduced amino acid sequence reveals putative transmembrane domains and conserved amino acid residues. Southern blot analysis of restriction digests of human genomic DNA indicates that these receptor subtypes are likely to belong to a family of related genes. One of the proposed receptor sequences indicates the presence of pseudogenes in this family. Based on the homology of these sequences to a family of recently described receptors expressed exclusively in rat olfactory epithelium, it is suggested that these receptors represent a family of human odorant receptors.
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Affiliation(s)
- L A Selbie
- Garvan Institute of Medical Research, Sydney, Australia
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39
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Abstract
The postnatal development of rat brain dopamine D2 receptor gene expression was investigated in animals 1 day to 1 year old. The level of expression of the striatal D2 mRNA was appreciable at birth (day 1), steadily increased to a maximum at day 28, and showed declines at ages 6 months and one year. The mRNA development profile was similar to that of [3H]spiroperidol binding in striatal membranes except that there was a lack of correlation between mRNA levels and [3H]spiroperidol binding during the early developmental periods. For example, although the mRNA expression at day 1 is about 75% of the 28-day value, the corresponding level of [3H]spiroperidol binding is only 15% of the value observed at day 28. Polymerase chain reaction (PCR) analysis of alternatively spliced forms of D2 receptor mRNA showed that the developmental expression of the two isoforms proceeded in parallel as the ratio of D2L and D2S mRNAs remained more or less constant in different age group of rats. In situ hybridization revealed a differential developmental profile of D2 mRNA for major dopaminergic regions of rat brain such as caudate putamen, nucleus accumbens, olfactory tubercle and substantia nigra.
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Affiliation(s)
- L K Srivastava
- Department of Psychiatry, Faculty of Health Sciences, McMaster University, Hamilton, Ontario, Canada
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40
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Martres MP, Sokoloff P, Giros B, Schwartz JC. Effects of dopaminergic transmission interruption on the D2 receptor isoforms in various cerebral tissues. J Neurochem 1992; 58:673-9. [PMID: 1309568 DOI: 10.1111/j.1471-4159.1992.tb09770.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We examined the effects of an interruption of dopamine neurotransmission, by either dopamine receptor blockade or degeneration of dopamine neurons by 6-hydroxydopamine, on the levels of D2 receptor mRNAs. In addition, we evaluated by the polymerase chain reaction (PCR) the relative abundance of the two D2 receptor isoform mRNAs generated by alternative splicing. Daily injections of 4 mg/kg of haloperidol to rats elicited in striatum a rapid and progressive increase in D2 receptor mRNA levels, which reached 70% after a 15-day treatment. By contrast, there was no apparent change in D2 receptor mRNA levels in cerebral cortex and pons-medulla, in spite of an increased density of D2 receptor in the former tissue. Using the PCR with primers flanking the alternative exon, we observed that the relative proportion of the shorter receptor isoform (D2S) mRNA was slightly but significantly enhanced in cerebral cortex (17%) and pons-medulla (18%) after a 15-day haloperidol treatment. Unilateral degeneration of dopamine neurons induced by local injection of 6-hydroxydopamine resulted in a marked decrease in levels of total D2 receptor mRNAs in substantia nigra (-79%) and ventral tegmental (-63%) area, two cell body areas. In the substantia nigra, the longer isoform (D2L) mRNA was significantly more decreased in content than the D2S isoform mRNA, so that there was a large enhancement in the relative abundance of the latter (81%).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- M P Martres
- Unité de Neurobiologie et Pharmacologie (U. 109) de l'INSERM, Centre Paul Broca, Paris, France
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41
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Abstract
The cloning of the dopamine (DA) D2 receptor now permits the characterization and regulation of D2 messenger RNA (mRNA) in the brain. In this article, the authors describe their studies delineating the distribution of D2 receptor mRNA in the rodent and primate brain, and compare the distribution of message to D2 receptor binding sites. The effects of chronic DA agonist and antagonist treatment on D2 receptor mRNA are also presented, and provide insights into receptor regulation. Finally, the autoreceptor role of D2 receptors located in the midbrain is examined with a combination of 6-hydroxydopamine lesions and anatomic colocalization studies with tyrosine hydroxylase. These preclinical results provide a framework for subsequent investigation into the nature of D2 receptor gene expression in postmortem brains from patients with disorders putatively associated with dopaminergic dysfunction, especially schizophrenia. They also lay the groundwork for a more profound understanding of DA neurocircuitry by combining molecular biological and traditional anatomical techniques.
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Affiliation(s)
- J H Meador-Woodruff
- Department of Psychiatry, University of Michigan Medical Center, Ann Arbor 48109-0720
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42
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Grandy DK, Zhang YA, Bouvier C, Zhou QY, Johnson RA, Allen L, Buck K, Bunzow JR, Salon J, Civelli O. Multiple human D5 dopamine receptor genes: a functional receptor and two pseudogenes. Proc Natl Acad Sci U S A 1991; 88:9175-9. [PMID: 1833775 PMCID: PMC52675 DOI: 10.1073/pnas.88.20.9175] [Citation(s) in RCA: 137] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Three genes closely related to the D1 dopamine receptor were identified in the human genome. One of the genes lacks introns and encodes a functional human dopamine receptor, D5, whose deduced amino acid sequence is 49% identical to that of the human D1 receptor. Compared with the human D1 dopamine receptor, the D5 receptor displayed a higher affinity for dopamine and was able to stimulate a biphasic rather than a monophasic intracellular accumulation of cAMP. Neither of the other two genes was able to direct the synthesis of a receptor. Nucleotide sequence analysis revealed that these two genes are 98% identical to each other and 95% identical to the D5 sequence. Relative to the D5 sequence, both contain insertions and deletions that result in several in-frame termination codons. Premature termination of translation is the most likely explanation for the failure of these genes to produce receptors in COS-7 and 293 cells even though their messages are transcribed. We conclude that the two are pseudogenes. Blot hybridization experiments performed on rat genomic DNA suggest that there is one D5 gene in this species and that the pseudogenes may be the result of a relatively recent evolutionary event.
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Affiliation(s)
- D K Grandy
- Vollum Institute for Advanced Biomedical Research, Oregon Health Sciences University
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43
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Sarkar G, Kapelner S, Grandy DK, Marchionni M, Civelli O, Sobell J, Heston L, Sommer SS. Direct sequencing of the dopamine D2 receptor (DRD2) in schizophrenics reveals three polymorphisms but no structural change in the receptor. Genomics 1991; 11:8-14. [PMID: 1837284 DOI: 10.1016/0888-7543(91)90096-w] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The dopamine D2 receptor gene (gene symbol DRD2) is a candidate gene for schizophrenia because the potency of certain neuroleptics correlates with their affinity for this receptor. Seven regions of likely functional significance including the coding sequences and the splice junctions were fully sequenced in the dopamine D2 receptor of 14 schizophrenics (and partially in several others) meeting DSM-III-R diagnostic criteria and in four unaffected non-Caucasians (97 kb of total sequence). No structural changes were found, suggesting that alteration in the structure of the dopamine D2 receptor is not commonly involved in the etiology of schizophrenia. However, two common and one uncommon intragenic polymorphisms were found. At least one of the polymorphisms was informative for linkage in 70% of Caucasians and 78% of Koreans.
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Affiliation(s)
- G Sarkar
- Department of Biochemistry and Molecular Biology, Mayo Clinic/Foundation, Rochester, Minnesota 55905
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44
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Mack KJ, Todd RD, O'Malley KL. The mouse dopamine D2A receptor gene: sequence homology with the rat and human genes and expression of alternative transcripts. J Neurochem 1991; 57:795-801. [PMID: 1861151 DOI: 10.1111/j.1471-4159.1991.tb08221.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
To understand the possible involvement of dopamine receptors in the pathogenesis of various neurological disorders, we have cloned and sequenced a dopamine D2A receptor gene from the mouse. A mouse genomic library was screened with probes derived from the published sequence of a rat D2A receptor cDNA. Using restriction endonuclease mapping, Southern blotting, and DNA sequencing, we have determined the cDNA sequence and genomic organization of the mouse D2A receptor gene. Unlike other guanine nucleotide-binding protein-coupled receptors, but similar to its rat and human counterparts, the mouse D2A receptor gene has seven introns and spans at least 30 kb of genomic DNA. The mouse D2A sequence shows 99% amino acid homology with the rat and 95% amino acid homology with the human sequence. As would be predicted, sequence differences are significantly more frequent outside of the hypothesized transmembrane spanning domain regions of the protein. Using the polymerase chain reaction with primers made from neighboring exons, we have identified two alternatively spliced D2A transcripts in the mouse. However, in contrast to the other species studied, the mouse expresses primarily the mRNA representing the larger, 444-amino-acid form of the receptor. Mouse pituitary expresses only the mRNA of the 444-amino-acid form of the D2A receptor. Hence, the mouse may offer the best model to study the in vivo physiology of the long form of the D2A receptor.
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Affiliation(s)
- K J Mack
- Department of Neurology, University of Wisconsin, Madison
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45
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Hall H, Högberg T, Halldin C, Bengtsson S, Wedel I. Synthesis and binding properties of the fluorinated substituted benzamide [3H]NCQ 115, a new selective dopamine D2 receptor ligand. Eur J Pharmacol 1991; 201:1-10. [PMID: 1686586 DOI: 10.1016/0014-2999(91)90315-h] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
[3H]NCQ 115 [R)-5-bromo-2,3-dimethoxy-N-[1-([2,5-3H]-4- fluorobenzyl)-2-pyrrolidinyl)methyl)benzamide) was prepared by acylation of (R)-(2-aminomethyl)-1- ([2,5-3H]-4-fluorobenzyl)pyrrolidine, which was obtained in a stereo-conservative synthesis from (R)-prolinamide. Purification by reversed phase high performance liquid chromatography (HPLC) gave [3H]NCQ 115 with a radiochemical purity of greater than 99% and a specific activity of 0.97 GBq/mumol (36 Ci/mmol). Saturation analyses, association and dissociation kinetics as well as binding competition with several compounds of various classes were performed with [3H]NCQ 115 in rat striatal homogenates. Saturation analyses in vitro showed that [3H]NCQ 115 bound to a single binding site with a Kd = 214 pM and Bmax = 35.4 fmol/mg. The binding of [3H]NCQ 115 was dependent upon sodium ions, since the number of binding sites was altered when sodium ions were excluded from the incubation medium. NCQ 115 inhibited the binding of [3H]raclopride to dopamine D2 receptors with high affinity (Ki = 147 pM), having much lower affinity for other receptors. The affinity of this substituted 1-benzyl-2-pyrrolidinylmethyl benzamide was confined to the (R)-enantiomer, which contrasts with that of the corresponding N-ethyl derivatives such as FLB 457, raclopride, eticlopride, sulpiride and NCQ 298, where the pharmacological activity is found in the (S)-enantiomer. It can be concluded that [3H]NCQ 115 binds to dopamine D2 receptors in the rat striatum with high affinity and high selectivity. [3H]NCQ 115 can also be used for in vivo binding studies of the brain. [18F]NCQ 115 may be a suitable ligand for positron emission tomography (PET) studies of the human brain in vivo.
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Affiliation(s)
- H Hall
- CNS2 Research and Development, Astra Research Centre AB, Södertälje, Sweden
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46
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Abstract
Because of their importance in pathophysiology, the dopamine receptors have been the subjects of intense pharmacological and physiological research. Their structures have remained mostly unknown until recently with the application of molecular biological approaches. The cloning of the first dopamine receptor, the D2 receptor opened a new era in dopamine receptor research. It has led not only to new studies of its own biology but also to the characterization of the other dopamine receptors. The most striking conclusion of this fast moving research is that the dopamine receptors are more diverse than expected from their pharmacological characterizations. We discuss here the history of the cloning of the dopamine receptors and the impact that this research had on our understanding of the dopamine system.
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Affiliation(s)
- O Civelli
- Vollum Institute for Advanced Biomedical Research, Oregon Health Sciences University, Portland 97201
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47
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Giros B, Martres MP, Pilon C, Sokoloff P, Schwartz JC. Shorter variants of the D3 dopamine receptor produced through various patterns of alternative splicing. Biochem Biophys Res Commun 1991; 176:1584-92. [PMID: 2039532 DOI: 10.1016/0006-291x(91)90469-n] [Citation(s) in RCA: 104] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Using Polymerase Chain Reaction amplification of mRNAs from several areas of rat brain we have shown the occurrence of two shorter transcripts of the dopamine D3 receptor gene, in addition to that corresponding to the D3 receptor. Cloning and sequencing of these transcripts, together with the establishment of the exon-intron organization of the D3 receptor gene, shown these transcripts to result from different processes of alternative splicing. The first transcript encodes a 100 amino acid protein, being produced by splicing of an exon whose absence deletes the third transmembrane domain and gives rise downstream to a frameshift in the open reading frame. In the second transcript, an in frame 54 bp deletion is produced by splicing occurring at an internal acceptor site, suppressing half of the second extracellular loop and a small sequence in the fifth transmembrane domain. This transcript was stably expressed in CHO cells which, however, failed to reveal any dopaminergic ligand binding activity. The functional significance and possible role of these shorter variants of the dopamine D3 receptor in cell signalling remain to be established.
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Affiliation(s)
- B Giros
- Unité de Neurobiologie et Pharmacologie (U-109) de I'INSERM, Centre Paul Broca, Paris, France
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48
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Sunahara RK, Guan HC, O'Dowd BF, Seeman P, Laurier LG, Ng G, George SR, Torchia J, Van Tol HH, Niznik HB. Cloning of the gene for a human dopamine D5 receptor with higher affinity for dopamine than D1. Nature 1991; 350:614-9. [PMID: 1826762 DOI: 10.1038/350614a0] [Citation(s) in RCA: 774] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Dopamine receptors belong to a superfamily of receptors that exert their biological effects through guanine nucleotide-binding (G) proteins. Two main dopamine receptor subtypes have been identified, D1 and D2, which differ in their pharmacological and biochemical characteristics. D1 stimulates adenylyl cyclase activity, whereas D2 inhibits it. Both receptors are primary targets for drugs used to treat many psychomotor diseases, including Parkinson's disease and schizophrenia. Whereas the dopamine D1 receptor has been cloned, biochemical and behavioural data indicate that dopamine D1-like receptors exist which either are not linked to adenylyl cyclase or display different pharmacological activities. We report here the cloning of a gene encoding a 477-amino-acid protein with strong homology to the cloned D1 receptor. The receptor, called D5, binds drugs with a pharmacological profile similar to that of the cloned D1 receptor, but displays a 10-fold higher affinity for the endogenous agonist, dopamine. As with D1, the dopamine D5 receptor stimulates adenylyl cyclase activity. Northern blot and in situ hybridization analyses reveal that the receptor is neuron-specific, localized primarily within limbic regions of the brain; no messenger RNA was detected in kidney, liver, heart or parathyroid gland. The existence of a dopamine D1-like receptor with these characteristics had not been predicted and may represent an alternative pathway for dopamine-mediated events and regulation of D2 receptor activity.
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MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Binding, Competitive
- Blotting, Northern
- Brain/metabolism
- Cell Line
- Cell Membrane/metabolism
- Cloning, Molecular
- Dopamine/metabolism
- Humans
- Kinetics
- Molecular Sequence Data
- Molecular Weight
- Oligonucleotide Probes
- RNA, Messenger/genetics
- RNA, Messenger/isolation & purification
- Rats
- Receptors, Dopamine/genetics
- Receptors, Dopamine/metabolism
- Receptors, Dopamine D1
- Receptors, Dopamine D5
- Sequence Homology, Nucleic Acid
- Transfection
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Affiliation(s)
- R K Sunahara
- Department of Pharmacology, University of Toronto, Ontario, Canada
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49
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Martens GJ, Molhuizen HO, Gröneveld D, Roubos EW. Cloning and sequence analysis of brain cDNA encoding a Xenopus D2 dopamine receptor. FEBS Lett 1991; 281:85-9. [PMID: 1826663 DOI: 10.1016/0014-5793(91)80364-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A D2 dopamine receptor pharmacologically different from the mammalian D2 receptor has previously been characterized in the amphibian Xenopus laevis. Here we report the cloning of a Xenopus D2 receptor which revealed about 75% amino acid sequence identity with its mammalian counterpart and the presence of an additional 33 amino acid sequence in the 3rd cytoplasmic loop instead of the additional 29 residues in the large form of the mammalian D2 receptor. All 7 predicted transmembrane domains are highly conserved between the Xenopus and mammalian D2 receptors, as are the 1st and 2nd intracellular loop, the 1st and 3rd extracellular loop and the carboxy-terminal portion of the receptors. The amino-terminal portion, the 2nd extracellular loop and the middle portion of the 3rd intracellular loop of these receptors, however, differ considerably. Knowledge of the locations of these regions of conservation and divergence within the D2 receptors of Xenopus and mammals will help to delineate portions of the receptor molecule that are functionally important. Interestingly, the 5'-untranslated region of the Xenopus D2 receptor mRNA contains 4 small open reading frames which may affect translational efficiency.
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Affiliation(s)
- G J Martens
- Department of Animal Physiology, University of Nijmegen, The Netherlands
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Neve KA, Neve RL, Fidel S, Janowsky A, Higgins GA. Increased abundance of alternatively spliced forms of D2 dopamine receptor mRNA after denervation. Proc Natl Acad Sci U S A 1991; 88:2802-6. [PMID: 1826366 PMCID: PMC51327 DOI: 10.1073/pnas.88.7.2802] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The existence of two molecular forms of D2 dopamine receptors suggests that differences in the distribution or regulation of the two forms could be exploited for the pharmacological treatment of disease. Using probes selective for each alternatively spliced variant of D2 receptor mRNA, we determined that both variants were widely distributed in rat brain and pituitary but that the ratio of the forms varied among regions. mRNA for the 444-amino acid-long variant, D2(444), was the most abundant form in pituitary and neostriatum. Intermediate levels of both D2(444) mRNA and the short form, D2(415), were detected in midbrain, and low levels of D2(444) and D2(415) mRNAs were detected in all other regions examined, including hippocampus, cerebellum, and cortex. The D2(444)/D2(415) ratio was generally lower in the regions of low expression than in pituitary and neostriatum. Dopamine-depleting lesions increased the density of D2 receptors in the denervated neostriatum by 29% without altering the affinity of the receptors for [3H]spiperone. The proliferation of receptors appeared to be due to a lesion-induced increase of up to 120% in the abundance of both variants of mRNA in the neostriatum.
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Affiliation(s)
- K A Neve
- Veterans Affairs Medical Center, Portland, OR
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