Pertussis toxin-mediated ADP-ribosylation of rabbit luteal Gi uncouples enkephalin inhibition of adenylyl cyclase.
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.
Abramowitz
J
J
Department of Zoology, Iowa State University of Science and Technology, Ames 50011-3223.
Campbell
A R
AR
Jena
B P
BP
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*
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