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

FEBS Lett. 1995 Apr 3;362(2):131-8. doi: 10.1016/0014-5793(95)00224-w.

Abstract

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 approximately 300 nM) and 6,7-ADTN (EC50 approximately 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 microM) 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 approximately 125nM) > SCH-23390(Kb approximately 230nM) > alpha-flupenthixol (Kb approximately 400 nM) > chlorpromazine > or = spiperone (Kb approximately 680 nM) > or = 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 conferring high affinity benzaepine receptor interactions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenylyl Cyclases / metabolism*
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Benzazepines / metabolism*
  • Conserved Sequence
  • Cyclic AMP / metabolism
  • Dopamine / pharmacology
  • Drosophila Proteins*
  • Drosophila melanogaster / chemistry*
  • GTP-Binding Proteins / metabolism
  • Gene Expression
  • Membrane Proteins / chemistry
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Molecular Sequence Data
  • Norepinephrine / pharmacology
  • RNA, Messenger / analysis
  • Receptors, Dopamine D1 / metabolism*
  • Receptors, Dopamine*
  • Sequence Homology
  • Serotonin / pharmacology
  • Spodoptera / metabolism
  • Tetrahydronaphthalenes / pharmacology
  • Transfection

Substances

  • Benzazepines
  • Dop1R1 protein, Drosophila
  • Drosophila Proteins
  • Membrane Proteins
  • RNA, Messenger
  • Receptors, Dopamine
  • Receptors, Dopamine D1
  • Tetrahydronaphthalenes
  • Serotonin
  • ADTN
  • Cyclic AMP
  • GTP-Binding Proteins
  • Adenylyl Cyclases
  • Dopamine
  • Norepinephrine

Associated data

  • GENBANK/U22106