Involvement of phosphatidylinositol 3 kinase in the progesterone-induced oocyte maturation in Rana dybowskii.
Previously, we observed that 70-kDa ribosomal protein S6 kinase (p70(s6k)) plays an essential role during the early phase of oocyte maturation in Rana dybowskii. To investigate further the early signal transduction components involved in this process, the possible role of phosphatidylinositol-3 kinase (PI3 kinase) during oocyte maturation was examined. Progesterone-induced oocyte maturation was significantly inhibited by wortmannin and LY294002, specific inhibitors of PI3 kinase. In contrast, protein kinase C activator 12-0-tetradecanoylphorbol-13-acetate-induced oocyte maturation was not inhibited by wortmannin. Protein synthesis was also significantly suppressed by wortmannin treatment during oocyte maturation. Moreover, PI3 kinase inhibitor suppressed progesterone-induced phosphorylation of S6 kinase in a dose-dependent manner. Likewise, PI3 kinase inhibitors significantly inhibited the phosphorylation of mitogen-activated protein (MAP) kinase which was increased during oocyte maturation. Finally, progesterone-induced H1 kinase activity was also inhibited by PI3 kinase inhibitors in a dose-dependent manner. Taken together, these results suggest that PI3 kinase is an initial component of the signal transduction pathway which precedes p70(s6k), MAP kinase, and MPF production during progesterone-induced maturation of amphibian oocyte.
Ju
Jung-Won
JW
Hormone Research Center, Chonnam National University, Kwangju 500-757, Republic of Korea.
Bandyopadhyay
Arun
A
Im
Wook-Bin
WB
Chung
Jongkyeong
J
Kwon
Hyuk Bang
HB
Choi
Hueng-Sik
HS
D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D002867:Chromones / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009025:Morpholines / Q000494:pharmacology; D009865:Oocytes / Q000187:drug effects / Q000502:physiology*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010766:Phosphorylation; D011374:Progesterone / Q000494:pharmacology*; D011898:Ranidae / Q000502:physiology*; D019893:Ribosomal Protein S6 Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D015398:Signal Transduction; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D000077191:Wortmannin
D000730:Androstadienes; D002867:Chromones; D004791:Enzyme Inhibitors; D020928:Mitogen-Activated Protein Kinases; D009025:Morpholines; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011374:Progesterone; D019893:Ribosomal Protein S6 Kinases; D013755:Tetradecanoylphorbol Acetate; D000077191:Wortmannin; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one