Pertussis toxin facilitates the progesterone-induced maturation of Xenopus oocyte. Possible role of protein phosphorylation.
Progesterone triggers the first meiotic cell division of Xenopus oocyte and inhibits cAMP synthesis. The effect of pertussis toxin purified from Bordetella pertussis was tested on the maturation of Xenopus oocyte. The toxin did not inhibit progesterone-induced resumption of meiosis or the hormone-induced drop in cAMP level. This indicates that progesterone action is not mediated by the Ni subunit of the oocyte adenylate cyclase. Furthermore, pertussis toxin caused a reduction in the time course of maturation correlated with the precocious appearance of an alkali stable 47 kDa phosphoprotein, a marker of the maturation promoting factor (MPF) activity. Pertussis toxin effects mimicked those of 2-glycerophosphate suggesting that both agents act on the steady-state level of phosphorylation implicated in MPF activity.
Mulner
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O
Megret
F
F
Alouf
J E
JE
Ozon
R
R
D037361:Adenylate Cyclase Toxin; D000818:Animals; D001427:Bacterial Toxins / Q000494:pharmacology*; D000242:Cyclic AMP / Q000096:biosynthesis; D005260:Female; D005994:Glycerophosphates / Q000494:pharmacology; D007700:Kinetics; D008540:Meiosis / Q000187:drug effects; D009865:Oocytes / Q000187:drug effects / Q000254:growth & development*; D037342:Pertussis Toxin; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D011374:Progesterone / Q000494:pharmacology*; D010566:Virulence Factors, Bordetella; D014982:Xenopus laevis
D037361:Adenylate Cyclase Toxin; D001427:Bacterial Toxins; D005994:Glycerophosphates; D010750:Phosphoproteins; D010566:Virulence Factors, Bordetella; D011374:Progesterone; D000242:Cyclic AMP; D037342:Pertussis Toxin; C031463:beta-glycerophosphoric acid