| First Author | Higashida H | Year | 2003 |
| Journal | J Neurochem | Volume | 85 |
| Issue | 5 | Pages | 1148-58 |
| PubMed ID | 12753074 | Mgi Jnum | J:309074 |
| Mgi Id | MGI:6756044 | Doi | 10.1046/j.1471-4159.2003.01751.x |
| Citation | Higashida H, et al. (2003) Subtype-specific coupling with ADP-ribosyl cyclase of metabotropic glutamate receptors in retina, cervical superior ganglion and NG108-15 cells. J Neurochem 85(5):1148-58 |
| abstractText | Cyclic ADP-ribose (cADP-ribose) is a putative second messenger or modulator. However, the role of cADP-ribose in the downstream signals of the metabotropic glutamate receptors (mGluRs) is unclear. Here, we show that glutamate stimulates ADP-ribosyl cyclase activity in rat or mouse crude membranes of retina via group III mGluRs or in superior cervical ganglion via group I mGluRs. The retina of mGluR6-deficient mice showed no increase in the ADP-ribosyl cyclase level in response to glutamate. GTP enhanced the initial rate of basal and glutamate-stimulated cyclase activity. GTP-gamma-S also stimulated basal activity. To determine whether the coupling mode of mGluRs to ADP-ribosyl cyclase is a feature common to individual cloned mGluRs, we expressed each mGluR subtype in NG108-15 neuroblastoma x glioma hybrid cells. The glutamate-induced stimulation of the cyclase occurs preferentially in NG108-15 cells over-expressing mGluRs1, 3, 5, and 6. Cells expressing mGluR2 or mGluRs4 and 7 exhibit inhibition or no coupling, respectively. Glutamate-induced activation or inhibition of the cyclase activity was eliminated after pre-treatment with cholera or pertussis toxin, respectively. Thus, the subtype-specific coupling of mGluRs to ADP-ribosyl cyclase via G proteins suggests that some glutamate-evoked neuronal functions are mediated by cADP-ribose. |
