Type 2 metabotropic glutamate receptor (mGluR2) fails to negatively couple to cGMP in stably transfected cells.
The group II metabotropic glutamate receptors 2 and 3 (mGluR2 and mGluR3) share sequence homology, common pharmacology and negative coupling to cAMP. We recently discovered that mGluR3 also is negatively coupled through a G-protein to the cGMP transduction pathway in rat cerebellar granule cells and astrocytes. To test the hypothesis that mGluR2 also has access to the cGMP pathway, C6 glioma cells were stably transfected with mGluR2 and mGluR3 cDNA and their coupling to cGMP levels was characterized. In contrast to many other cell lines, C6 has a robust cGMP response that makes it attractive in the study of receptor coupling to this second messenger pathway. Consistent with prior studies, the mGluR3 receptor was negatively coupled to cGMP and this coupling was blocked by PTX. In contrast, mGluR2 agonists failed to reduce sodium nitroprusside stimulated cGMP levels in transfected cell lines where the receptor was negatively coupled to cAMP. These data provide further support for the functional divergence between these two closely related receptors.
Department of Biology, Georgetown University, 2115 49th Sts., NW, Washington, DC 20057, USA.
Barbara
B
Wroblewska
Iga N
IN
Wegorzewska
Tomasz
T
Bzdega
Joseph H
JH
Neale
D000818:Animals; D045744:Cell Line, Tumor; D006152:Cyclic GMP / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D037342:Pertussis Toxin / Q000494:pharmacology; D051381:Rats; D018094:Receptors, Metabotropic Glutamate / Q000235:genetics* / Q000378:metabolism*; D015290:Second Messenger Systems / Q000187:drug effects / Q000235:genetics*; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics*; D014162:Transfection / Q000379:methods
D018076:DNA, Complementary; D020030:Nitric Oxide Donors; D018094:Receptors, Metabotropic Glutamate; C108822:metabotropic glutamate receptor 2; C102718:metabotropic glutamate receptor 3; D009599:Nitroprusside; D037342:Pertussis Toxin; D006152:Cyclic GMP