title: Pertussis toxin-mediated ADP-ribosylation of rabbit luteal Gi uncouples enkephalin inhibition of adenylyl cyclase.
abstract: 1. Some of the actions of pertussis toxin on the rabbit luteal adenylyl cyclase system were analyzed. 2. Incubation of luteal membranes with pertussis toxin and [32P]NAD resulted in the [32P]ADP-ribosylation of a 40,000 Da protein that is distinct from the proteins ADP-ribosylated by cholera toxin. 3. Pertussis toxin specific [32P]ADP-ribosylation was time-dependent and dependent upon the concentration of pertussis toxin present during the incubation. 4. Pertussis toxin mediated [32P]ADP-ribosylation was enhanced by ATP, ADP, adenylyl imidodiphosphate, GTP, guanosine-5'-O-(2-thiodiphosphate), guanosine-5'-O-(3-thiotriphosphate), and NaF but not AMP or guanylyl imidodiphosphate [GMP-P(NH)P]. 5. Treatment of luteal membranes with NAD and pertussis toxin prevents GTP and enkephalin but not GMP-P(NH)P mediated inhibition of forskolin stimulated adenylyl cyclase, demonstrating the existence of a functional Gi in the rabbit corpus luteum.
authors.affiliation: Department of Zoology, Iowa State University of Science and Technology, Ames 50011-3223.
authors.forename: J
authors.initials: J
authors.lastname: Abramowitz
authors.forename: A R
authors.initials: AR
authors.lastname: Campbell
authors.forename: B P
authors.initials: BP
authors.lastname: Jena
mesh_terms: D000246:Adenosine Diphosphate Ribose / Q000378:metabolism*; D037361:Adenylate Cyclase Toxin; D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D003338:Corpus Luteum / Q000187:drug effects / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004745:Enkephalins / Q000494:pharmacology*; D005260:Female; D019204:GTP-Binding Proteins / Q000378:metabolism*; D037342:Pertussis Toxin; D011817:Rabbits; D014475:Uncoupling Agents / Q000494:pharmacology*; D010566:Virulence Factors, Bordetella / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D037361:Adenylate Cyclase Toxin; D000067956:Adenylyl Cyclase Inhibitors; D004745:Enkephalins; D014475:Uncoupling Agents; D010566:Virulence Factors, Bordetella; D000246:Adenosine Diphosphate Ribose; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins; D000262:Adenylyl Cyclases