Cloning and functional characterization of a novel dopamine receptor from Drosophila melanogaster.


Journal Article

A cDNA clone is described that encodes a novel G-protein-coupled dopamine receptor (DopR99B) expressed in Drosophila heads. The DopR99B receptor maps to 99B3-5, close to the position of the octopamine/tyramine receptor gene at 99A10-B1, suggesting that the two may be related through a gene duplication. Agonist stimulation of DopR99B receptors expressed in Xenopus oocytes increased intracellular Ca2+ levels monitored as changes in an endogenous inward Ca2+-dependent chloride current. In addition to initiating this intracellular Ca2+ signal, stimulation of DopR99B increased cAMP levels. The rank order of potency of agonists in stimulating the chloride current is: dopamine > norepinephrine > epinephrine > tyramine. Octopamine and 5-hydroxytryptamine are not active (< 100 microM). This pharmacological profile plus the second-messenger coupling pattern suggest that the DopR99B receptor is a D1-like dopamine receptor. However, the hydrophobic core region of the DopR99B receptor shows almost equal amino acid sequence identity (40-48%) with vertebrate serotonergic, alpha 1- and beta-adrenergic, and D1-like and D2-like dopaminergic receptors. Thus, this Drosophila receptor defines a novel structural class of dopamine receptors. Because DopR99B is the second dopamine receptor cloned from Drosophila, this work establishes dopamine receptor diversity in a system amenable to genetic dissection.

Full Text

Cited Authors

  • Feng, G; Hannan, F; Reale, V; Hon, YY; Kousky, CT; Evans, PD; Hall, LM

Published Date

  • June 1996

Published In

Volume / Issue

  • 16 / 12

Start / End Page

  • 3925 - 3933

PubMed ID

  • 8656286

Pubmed Central ID

  • 8656286

Electronic International Standard Serial Number (EISSN)

  • 1529-2401

International Standard Serial Number (ISSN)

  • 1529-2401

Digital Object Identifier (DOI)

  • 10.1523/jneurosci.16-12-03925.1996


  • eng