DmGluRA, a Drosophila metabotropic glutamate receptor, activates G-protein inwardly rectifying potassium channels in Xenopus oocytes.
Xenopus oocytes were coinjected with cDNAs encoding the Drosophila melanogaster metabotropic glutamate receptor (DmGluRA) and two mammalian G-protein inwardly rectifying potassium channel subunits (GIRK1 and GIRK2). Glutamate and two vertebrate group II mGluR agonists (order of potency: LY 354740 > glutamate > DCG IV) elicited inwardly rectifying potassium currents. These inward currents were sensitive to cesium and barium. They were also blocked by two group II specific antagonists MCCG and APICA (IC50s 97.5 and 200 microM, respectively) and not affected by a group I antagonist (AIDA). Finally, the A-protomer of PTX reduced the glutamate-induced GIRK currents. This study is the first characterization of an invertebrate mGluR-mediated GIRK currents via a PTX-sensitive G protein.
Raymond
V
V
Laboratoire de Neurophysiologie, UPRES EA 2647, Université d'Angers, France.
Hamon
A
A
Grau
Y
Y
Lapied
B
B
D000818:Animals; D004331:Drosophila melanogaster; D051676:G Protein-Coupled Inwardly-Rectifying Potassium Channels; D019204:GTP-Binding Proteins / Q000187:drug effects / Q000378:metabolism*; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism*; D015221:Potassium Channels / Q000187:drug effects* / Q000378:metabolism*; D024661:Potassium Channels, Inwardly Rectifying; D018094:Receptors, Metabotropic Glutamate / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014981:Xenopus
D051676:G Protein-Coupled Inwardly-Rectifying Potassium Channels; D015221:Potassium Channels; D024661:Potassium Channels, Inwardly Rectifying; D018094:Receptors, Metabotropic Glutamate; C108822:metabotropic glutamate receptor 2; D019204:GTP-Binding Proteins