title: Glucose uptake by C6 glioma cells is mediated by G(q alpha).
abstract: The role of G proteins in glucose uptake was investigated using C6 glioma cells. Carbachol (an agonist acting via G protein coupled receptors) and 5'-guanylylimidodiphosphate (Gpp(NH)p; a nonhydrolysable guanine nucleotide analog which bypasses the receptors and directly activates G proteins) stimulated [3H]2-deoxy-D-glucose (2DG) uptake by C6 cells, suggesting that hexose uptake is a G protein-mediated process. To identify the G protein involved in glucose uptake by C6 cells, the effect of carbachol on 2DG uptake was examined in the presence of pertussis toxin. Pertussis toxin treatment did not alter the ability of C6 cells to respond to carbachol, ruling out the involvement of G(i alpha) in 2DG uptake. C6 cells were transfected with G(q alpha) or GLUT1 cDNA for 48 h, exposed to 1 mM carbachol for 2 h, and processed for 2DG uptake. Carbachol stimulated 2DG uptake in both G(q alpha) and GLUT1-transfected cells. Gpp(NH)p, also stimulated 2DG uptake in G(q alpha) and GLUT1-transfected cells. These results suggest that muscarinic receptor coupling to G(q alpha) regulates hexose uptake in C6 cells.
authors.affiliation: Endocrine-Metabolic Division, Veterans Affairs Medical Center and Finch University of Health Sciences/The Chicago Medical School, North Chicago, IL 60064, USA.
authors.forename: S P
authors.initials: SP
authors.lastname: Singh
authors.forename: Y
authors.initials: Y
authors.lastname: Gao
authors.forename: S P
authors.initials: SP
authors.lastname: Kunapuli
authors.forename: R
authors.initials: R
authors.lastname: Ravindra
mesh_terms: D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D003847:Deoxyglucose / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000502:physiology*; D005910:Glioma / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D006165:Guanylyl Imidodiphosphate / Q000378:metabolism; D037342:Pertussis Toxin; D051381:Rats; D013268:Stimulation, Chemical; D014407:Tumor Cells, Cultured; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
chemical_list: D010566:Virulence Factors, Bordetella; D006165:Guanylyl Imidodiphosphate; D002217:Carbachol; D003847:Deoxyglucose; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins; D005947:Glucose