Cytoplasmic polyadenylation controls cdc25B mRNA translation in rat oocytes resuming meiosis
Cytoplasmic polyadenylation controls cdc25B mRNA translation in rat oocytes resuming meiosis
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DOI：
10.1530/rep.1.01093
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发表时间：
2006-07-01
期刊：
影响因子：
3.8
通讯作者：
Dekel, Nava
中科院分区：
文献类型：
--
作者：
Gershon, Eran;Galiani, Dalia;Dekel, Nava
卵母细胞减数分裂的恢复代表细胞周期进入M期，并受成熟促进因子(MPF)的调节。MPF的激活是由双特异性磷酸酶CDC25催化的。在哺乳动物中，CDC25由A、B和C三种亚型组成的多基因家族代表。最近有报道称，缺乏CDC25B的雌性小鼠表现出生育能力下降，这表明该亚型在调节哺乳动物卵母细胞从G2到M的转变中发挥了作用。为了支持上述观察，我们在这里证明了微量注射抗cdc25B的中和抗体干扰了大鼠卵母细胞经历生发泡破裂(GVB)的能力。我们还发现cdc25B在GVB卵母细胞中积累，并在减数分裂中期I出现一过性的减少。Cdc25B的蓄积与其信使核糖核酸胞内多聚腺苷有关，并被蛋白质合成抑制剂环己胺和多腺苷抑制剂虫草素所抑制。免疫荧光染色显示cdc25B易位到11中期纺锤体。综上所述，我们的发现为cdc25B参与大鼠卵母细胞减数分裂的恢复提供了证据。我们还首次证明了cdc25B在减数分裂过程中的周期性积累，这种积累是翻译调控的，涉及cdc25B mRNA的聚腺苷酸化。
Resumption of meiosis in oocytes represents the entry into M-phase of the cell cycle and is regulated by the maturation-promoting factor (MPF). Activation of MPF is catalyzed by the dual specificity phosphatase, cdc25. In mammals, cdc25 is represented by a multigene family consisting of three isoforms: A, B and C. A recent report that female mice lacking cdc25B exhibit impaired fertility suggests a role for this isoform in regulating the G2- to M-transition in mammalian oocytes. Supporting the above-mentioned observation, we demonstrate herein that microinjection of neutralizing antibodies against cdc25B interfered with the ability of rat oocytes to undergo germinal vesicle breakdown (GVB). We also show accumulation of cdc25B in GVB oocytes and a transient reduction in its amount at metaphase I of meiosis. The accumulation of cdc25B was associated with its mRNA cytoplasmatic polyadenylation and was prevented by the protein synthesis inhibitor cyclohexamide as well as by the polyadentylation inhibitor cordycepin. Immunofluorescence staining revealed translocation of cdc25B to the metaphase 11 spindle apparatus. Taken together, our findings provide evidence that cdc25B is involved in resumption of meiosis in rat oocytes. We further demonstrate for the first time, a periodic accumulation of cdc25B throughout meiosis that is translationally regulated and involves cdc25B mRNA polyadenylation.