Effect of Bordetella pertussis toxin on ADP-ribosylation of membrane proteins, adenylate cyclase activity and insulin release in rat pancreatic islets

Abstract

Exposure of rat pancreatic islet membranes to [α- 32P]-NAD + in the presence of Bordetella Pertussis toxin (islet-activating protein) reveals the ADP-ribosylation of a peptide with a Mr close to 41 kDa, which corresponds to the α-subunit of the guanine nucleotide regulatory protein Ni. Islets removed from rats pretreated with the Bordetella Pertussis toxin display a specific increase in adenylate cyclase responsiveness to GTP and are characterized by a resistance to the inhibitory action of α 2-adrenergic agonists upon either adenylate cyclase activity or glucose-induced insulin release.