title: 2',3'-Dialdehyde of GTP blocks regulatory functions of adenylate cyclase NS protein.
abstract: Preincubation of bovine caudate nucleus membranes with the 2',3'-dialdehyde of GTP (oGTP) reduces adenylate cyclase activation by guanylyl imidodiphosphate (GppNHp) in a time-dependent fashion. A slower rate of inhibition is observed if membranes are treated with both GTP and oGTP. The efficacy of oGTP action is enhanced by raising the Mg2+ concentration. Reduction of adenylate cyclase sensitivity to GppNHp is followed by an irreversible decrease of enzyme stimulation by forskolin. Addition of a Lubrol soluble preparation from guinea pig lung membranes to oGTP-treated caudate nucleus membranes causes restoration of the adenylate cyclase sensitivity to GppNHp. These data suggest that oGTP blocks the GTP-binding site of the adenylate cyclase system localized on the Ns protein. Such modification leads to the elimination of the Ns-mediated regulation of the enzyme.
mesh_terms: D000067956:Adenylyl Cyclase Inhibitors; D000818:Animals; D002417:Cattle; D002421:Caudate Nucleus / Q000201:enzymology*; D005576:Colforsin; D004224:Diterpenes / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D006168:Guinea Pigs; D007700:Kinetics; D008168:Lung / Q000032:analysis; D008274:Magnesium / Q000494:pharmacology; D011092:Polyethylene Glycols / Q000494:pharmacology
chemical_list: D000067956:Adenylyl Cyclase Inhibitors; D004224:Diterpenes; D005576:Colforsin; D006165:Guanylyl Imidodiphosphate; D011092:Polyethylene Glycols; C005092:lubrol; C037756:2-(guanylformylmethoxy)-3-(triphospho)propanal; D006160:Guanosine Triphosphate; D008274:Magnesium