A primordial dopamine D1‐like adenylyl cyclase‐linked receptor from Drosophila melanogaster displaying poor affinity for benzazepines

FEBS Letters

Sugamori, Kim S.³  Forte, Michael A.⁴  McConkey, Fortunata¹  Niznik, Hyman B.²  Demchyshyn, Lidia L.³ 

[1] Laboratory of Molecular Neurobiology, Clarke Institute of Psychiatry, 250 College Street, Toronto, Ont., M5T 1R8, Canada;Department of Psychiatry, University of Toronto, Toronto, Ont., M5S 1A8, Canada;Department of Pharmacology, University of Toronto, Toronto, Ont., M5S 1A8, Canada;Vollum Institute for Advanced Biomedical Research, Portland, OR 97201, USA

关键词: G protein-coupled receptor;    Invertebrate;    cAMP;    Catecholamine Sequences reported in this paper have been deposited in GenBank with Accession Number U22106;    (±)-6;    7-ADTN;    6;    7-dihyroxy-2-aminotetralin;    CY 208-243;    (−)-4;    6;    6a;    7;    8;    12b-hexahydro-7-methyl-indolo[4;    3-ab]-phenanthridine;    DA;    dopamine;    DHA;    dihydroalprenolol;    8-OH-DPAT;    (±)-8-hydroxy-N;    N-dipropyl-2-aminotetralin;    5-HT;    serotonin (5-hydroxytryptamine);    L-dopa;    l-3;    4-dihydroxphenylalanine;    LSD;    lysergic acid diethylamine;    NE;    norepinephrine;    N(−)-NPA;    N-propyl-norapomorphine;    SCH-23390;    (R)-(+)-7-chloro-8-hydroxy-3-methyl-1-pheny1-2;    3;    4;    5-tetrahydro-1H-3-benzazepine;    SKF-38393;    2;    3;    4;    5-tetrahydro-7;    8-dihydroxy-1-phenyl-1H-3-benzazepine;    SKF-81927;    6-chloro-7;    8dihydroxy-l-phenyl-2;    3;    4;    5-tetrahydro-1H-3-benzazepine;    SKF-82526;    6-chloro-7;    8-dihydroxy-1-(p-hydroxyphenyl)-2;    3;    4;    5-tetrahydro-(1H)3-benzazepine;    TM;    transmembrane;    WB-4101;    2-(2;    6-dimethoxyphenoxyethyl)aminomethyl-1;    4-benzodioxane;    YM-09151-2;    cis-N-(1-benzyl-2-methylpyrrolidin-3-yl)-5-chloro-2-methoxy-4-methylamino-benzamide;   

DOI  :  10.1016/0014-5793(95)00224-W

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We report here the isolation from Drosophila melanogaster of a 2.0 kb cDNA clone encoding a 385 amino acid protein (dDA1) displaying, within putative transmembrane domains, highest amino acid sequence homology (49–53%) to members of the vertebrate dopamine D1-like receptor family. When expressed in either Sf9 or COS-7 cells, dDA1 did not bind the specific D1-like receptor antagonist [³H]SCH-23390 or numerous other dopaminergic, adrenergic or serotoninergic ligands with high affinity. However, like vertebrate dopamine D1-like receptors, dDA1 stimulated the accumulation of cAMP in response to DA (EC₅₀ ∼300 nM) and 6,7-ADTN (EC₅₀∼500 nM). The dopaminergic rank order of potency (DA > NE⪢5-HT) and the lack of stimulation by other possible neurotransmitters (octopamine, tyramine, tryptamine) or DA metabolites (e.g. N-acetyl dopamine) found in Drosophila suggests that this receptor functionally belongs to the dopamine D1-like subfamily. Benzazepines, which characteristically bind to vertebrate dopamine D1-like receptors with high affinity, were relatively poor in stimulating (SKF-38393, SKF-82526; EC₅₀ > 10 μM) dDA1-mediated accumulation of cAMP. Of the numerous compounds tested, a few dopaminergic antagonists inhibited DA-stimulated production of cAMP in a concentration-dependent manner, albeit with considerably reduced affinity, and with the rank order of potency: (+)-butaclamol(K _b∼125nM) > SCH-23390(K _b∼230nM) > α-flupenthixol (K _b ∼ 400 nM) > chlorpromazine ≥ spiperone (K _b ∼ 680 nM) ≥ clozapine In situ hybridization revealed that dDA1 receptor mRNA is expressed as a maternal transcript, and at later blastoderm stages is restricted to apical regions of the cortical peripheral cytoplasm. The generation of inter-species D1 receptor chimeras may help to identify those particular sequence-specific motifs or amino acid residues confering high affinity benzazepine receptor interactions.

【 授权许可】

Unknown