TY - JOUR
T1 - A primordial dopamine D1-like adenylyl cyclase-linked receptor from Drosophila melanogaster displaying poor affinity for benzazepines
AU - Sugamori, Kim S.
AU - Demchyshyn, Lidia L.
AU - McConkey, Fortunata
AU - Forte, Michael A.
AU - Niznik, Hyman B.
N1 - Funding Information:
Acknowledgements: The authors wish to thank S. Hamadanizadeh, M. Chung, H.-C. Guan, and P. Seeman for excellent technical advice and assistance. This work was supported in part by grants from the Medical Research Council of Canada (PG-11121), the Ontario Friends of Schizophrenia and the Ontario Mental Health Foundation. K.S.S. is a recipient of a Medical Research Council studentship, and L.L.D. is supported by an Ontario Mental Health Foundation studentship. H.B.N. was supported by a National Association for Research on Schizophrenia and Depression Established Investigator Award, and is a Career Scientist of the Ontario Ministry of Health.
PY - 1995/4/3
Y1 - 1995/4/3
N2 - 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(Kb∼125nM) > SCH-23390(Kb∼230nM) > α-flupenthixol (Kb ∼ 400 nM) > chlorpromazine ≥ spiperone (Kb ∼ 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.
AB - 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(Kb∼125nM) > SCH-23390(Kb∼230nM) > α-flupenthixol (Kb ∼ 400 nM) > chlorpromazine ≥ spiperone (Kb ∼ 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.
KW - Catecholamine Sequences reported in this paper have been deposited in GenBank with Accession Number U22106
KW - G protein-coupled receptor
KW - Invertebrate
KW - cAMP
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U2 - 10.1016/0014-5793(95)00224-W
DO - 10.1016/0014-5793(95)00224-W
M3 - Article
C2 - 7720859
AN - SCOPUS:0028934161
SN - 0014-5793
VL - 362
SP - 131
EP - 138
JO - FEBS Letters
JF - FEBS Letters
IS - 2
ER -