Rapid, nongenomic responses to ecdysteroids and catecholamines mediated by a novel Drosophila G-protein-coupled receptor.
J Neurosci
; 25(26): 6145-55, 2005 Jun 29.
Article
in En
| MEDLINE
| ID: mdl-15987944
ABSTRACT
Nongenomic response pathways mediate many of the rapid actions of steroid hormones, but the mechanisms underlying such responses remain controversial. In some cases, cell-surface expression of classical nuclear steroid receptors has been suggested to mediate these effects, but, in a few instances, specific G-protein-coupled receptors (GPCRs) have been reported to be responsible. Here, we describe the activation of a novel, neuronally expressed Drosophila GPCR by the insect ecdysteroids ecdysone (E) and 20-hydroxyecdysone (20E). This is the first report of an identified insect GPCR interacting with steroids. The Drosophila melanogaster dopamine/ecdysteroid receptor (DmDopEcR) shows sequence homology with vertebrate beta-adrenergic receptors and is activated by dopamine (DA) to increase cAMP levels and to activate the phosphoinositide 3-kinase pathway. Conversely, E and 20E show high affinity for the receptor in binding studies and can inhibit the effects of DA, as well as coupling the receptor to a rapid activation of the mitogen-activated protein kinase pathway. The receptor may thus represent the Drosophila homolog of the vertebrate "gamma-adrenergic receptors," which are responsible for the modulation of various activities in brain, blood vessels, and pancreas. Thus, DmDopEcR can function as a cell-surface GPCR that may be responsible for some of the rapid, nongenomic actions of ecdysteroids, during both development and signaling in the mature adult nervous system.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Catecholamines
/
Drosophila Proteins
/
Receptors, G-Protein-Coupled
/
Drosophila melanogaster
Limits:
Animals
Language:
En
Journal:
J Neurosci
Year:
2005
Document type:
Article
Affiliation country:
United kingdom