LOCALIZATION OF THE G(S)-PROTEIN SITES IN TERACTING WITH ADENYLYL-CYCLASE BY G(S) G(O) CHIMERAS DESIGN/

cDNAs coding for three types of alpha-subunits of GTP-binding proteins G(s) and G0 (a short form of alpha(s) with Asp-Ser in positions 71 an d 72, a long form of alpha(s) with the insertion of 16 amino acid resi dues instead of Asp-Ser (71-72) - both from bovine brain, and alpha0 f rom bovine cerebellum) as well as some chimeric alpha(s)/alpha0 genes were cloned into a modified pGEM-2 plasmid vector under the control of the SP6 promoter, All the genes were in vitro transcribed and transla ted, and some functional properties of the resulting proteins were det ermined, such as adenylyl cyclase activation, ADP-ribosylation with pe rtussis toxin, limited nucleotide-dependent trypsin proteolysis. Parts ' of the alpha(s) polypeptide chain necessary for the activation of ad enylyl cyclase. were mapped. The alpha(s) domain interacting with aden ylyl cyclase is formed by the alpha(s) polypeptide chain fragments 235 -294 and 337-356 (numbering as of the alpha(s) long form).