Okadaic acid, a specific protein phosphatase inhibitor, induces maturation and MPF formation in Xenopus laevis oocytes.
Micro-injection of, or incubation with okadaic acid (OA), a specific phosphatase inhibitor, can induce formation of maturation-promoting factor (MPF) and germinal vesicle breakdown (GVBD) in Xenopus laevis oocytes. Comparison of the dose-response curves of OA on maturation, isolated enzymes and phosphatase activities in crude oocyte preparations suggests that inhibition of both polycation-stimulated (PCS) and ATP,Mg-dependent (AMD) phosphatases is sufficient but requires that a critical phosphorylation level is attained of one or several of their substrates, resulting in the formation of active MPF and meiotic maturation.
Goris
J
J
Afdeling Biochemie, Faculteit Geneeskunde, Katholieke Universiteit Leuven, Belgium.
Hermann
J
J
Hendrix
P
P
Ozon
R
R
Merlevede
W
W
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D002412:Cations; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004988:Ethers, Cyclic / Q000494:pharmacology*; D005260:Female; D006133:Growth Substances / Q000096:biosynthesis*; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D016200:Maturation-Promoting Factor; D019319:Okadaic Acid; D009865:Oocytes / Q000187:drug effects / Q000502:physiology*; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors*; D011374:Progesterone / Q000494:pharmacology; D011817:Rabbits; D014982:Xenopus laevis
D002412:Cations; D004988:Ethers, Cyclic; D006133:Growth Substances; D019319:Okadaic Acid; D011374:Progesterone; D000255:Adenosine Triphosphate; D016200:Maturation-Promoting Factor; D010749:Phosphoprotein Phosphatases; D008274:Magnesium