title: Antibodies against a retinal guanine nucleotide-binding protein cross-react with a single plasma membrane protein in non-retinal tissues.
abstract: Antisera (AS/1-AS/6) to purified bovine retinal transducin, a guanine nucleotide-binding protein, were produced in 6 rabbits. Immunoblots showed that the antisera varied in their reactivity with the subunits of transducin; AS/1 reacted strongly with all 3 subunits, while the others reacted with only the beta and/or gamma subunits. Only AS/1 specifically immunoprecipitated the alpha subunit radiolabeled with non-covalently bound guanine nucleotides. Immunostaining of plasma membrane proteins from non-retinal tissues with AS-1 revealed a single protein (approx. 35 kDa), most likely representing the beta subunit of the guanine nucleotide-binding proteins (Gs and Gi) associated with adenylate cyclase. Cerebral cortex showed the highest content of this protein. Antisera against transducin provide a highly specific and sensitive probe for quantitation of the beta subunit of Gs and Gi.
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D002417:Cattle; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology*; D019204:GTP-Binding Proteins; D007106:Immune Sera / Q000276:immunology*; D007122:Immunoelectrophoresis; D007163:Immunosorbent Techniques; D046911:Macromolecular Substances; D008565:Membrane Proteins / Q000276:immunology*; D011817:Rabbits / Q000276:immunology; D011956:Receptors, Cell Surface / Q000276:immunology*; D012160:Retina / Q000276:immunology*; D012374:Rod Cell Outer Segment / Q000276:immunology; D014018:Tissue Distribution; D015293:Transducin
chemical_list: D000939:Epitopes; D007106:Immune Sera; D046911:Macromolecular Substances; D008565:Membrane Proteins; D011956:Receptors, Cell Surface; D019204:GTP-Binding Proteins; D015293:Transducin