- Treatment of intact striatal neurones with cholera toxin or 8-bromoadenosine 3',5'-(cyclic)phosphate decreases the ability of pertussis toxin to ADP-ribosylate the alpha-subunits of inhibitory and other guanine-nucleotide-binding regulatory proteins, Gi and Go. Evidence for two distinct mechanisms. Maus, M., Homburger, V., Cordier, J., Pantaloni, C., Bockaert, J., Glowinski, J., Prémont, J. Eur. J. Biochem. (1991)