Use of pertussis toxin to investigate the mechanism of action of prostaglandin F2 alpha on the corpus luteum in sheep.
Pertussis toxin catalysed the ADP-ribosylation of a protein of M(r) 40,000 in ovine luteal tissue. Ribosylation of 45% of this protein in whole cell incubations (as judged by subsequent ribosylation of cell-free preparations in the presence of [32P]NAD) attenuated the prostaglandin (PG)F2 alpha-stimulated hydrolysis of [3H]inositol-labelled phosphatidylinositol-4,5-bisphosphate into inositol trisphosphate by 60%, but did not affect the inhibition by PGF2 alpha of LH-stimulated accumulation of cyclic AMP. It is concluded that activation of phospholipase C by PGF2 alpha involves a pertussis toxin-sensitive protein, probably a G protein, and that the inhibitory effect of PGF2 alpha on LH-stimulated adenylate cyclase is unlikely to be directly mediated by such a protein.
Institute of Animal Physiology and Genetics Research, Babraham, Cambridge, UK.
T J
TJ
McCann
A P
AP
Flint
D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D037361:Adenylate Cyclase Toxin; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D003338:Corpus Luteum / Q000187:drug effects* / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D015237:Dinoprost / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D019204:GTP-Binding Proteins / Q000378:metabolism; D006868:Hydrolysis; D066298:In Vitro Techniques; D007986:Luteinizing Hormone / Q000494:pharmacology; D008565:Membrane Proteins / Q000378:metabolism; D037342:Pertussis Toxin; D010716:Phosphatidylinositols / Q000378:metabolism; D012756:Sheep; D010738:Type C Phospholipases / Q000378:metabolism; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
D037361:Adenylate Cyclase Toxin; D008565:Membrane Proteins; D010716:Phosphatidylinositols; D010566:Virulence Factors, Bordetella; D000246:Adenosine Diphosphate Ribose; D007986:Luteinizing Hormone; D015237:Dinoprost; D000242:Cyclic AMP; D037342:Pertussis Toxin; D010738:Type C Phospholipases; D019204:GTP-Binding Proteins; D000262:Adenylyl Cyclases