The mitogen-activated protein kinase signaling pathway stimulates Mos mRNA cytoplasmic polyadenylation during <i>Xenopus</i> oocyte maturation

作     者：Howard, EL Charlesworth, A Welk, J MacNicol, AM 

作者机构：Univ Chicago Dept Med Chicago IL 60637 USA Univ Chicago Comm Dev Biol Chicago IL 60637 USA Univ Chicago Comm Canc Biol Chicago IL 60637 USA 

出 版 物：《MOLECULAR AND CELLULAR BIOLOGY》 (分子生物学与细胞生物学)

年 卷 期：1999年第19卷第3期

页      面：1990-1999页

核心收录：

学科分类：0710[理学-生物学] 071010[理学-生物化学与分子生物学] 07[理学] 

基　　金：NHLBI NIH HHS [T32 HL007381  5 T32 HL07381-17] Funding Source: Medline 

主　　题：钙-钙调素依赖性蛋白激酶类/代谢 细胞周期蛋白B/遗传学 细胞周期蛋白B1 细胞质 成熟促进因子/代谢 卵母细胞/生理学 聚腺苷酸类 蛋白质生物合成 原癌基因蛋白质c-mos/遗传学 RNA 信使 信号传导 爪蟾属 动物 

摘      要：The Mos protein kinase is a key regulator of vertebrate oocyte maturation. Oocyte-specific Mos protein expression is subject to translational control. In the frog Xenopus, the translation of Mos protein requires the progesterone-induced polyadenylation of the maternal Mos mRNA, which is present in the oocyte cytoplasm. Both the Xenopus p42 mitogen-activated protein kinase (MAPK) and maturation-promoting factor (MPF) signaling pathways have been proposed to mediate progesterone-stimulated oocyte maturation. In this study, we have determined the relative contributions of the MAPK and MPF signaling pathways to Mos mRNA polyadenylation. We report that progesterone-induced Mos mRNA polyadenylation was attenuated in oocytes expressing the MAPK phosphatase rVH6. Moreover, inhibition of MAPK signaling blocked progesterone-induced Mos protein accumulation. Activation of the MAPK pathway by injection of RNA encoding Mos was sufficient to induce both the polyadenylation of synthetic Mos mRNA substrates and the accumulation of endogenous Mos protein in the absence of MPF signaling. Activation of MPF, by injection of cyclin BI RNA or purified cyclin B1 protein, also induced both Mos protein accumulation and Mos mRNA polyadenylation, However, this action of MPF required MAPK activity. By contrast, the cytoplasmic polyadenylation of maternal cyclin B1 mRNA nas stimulated by MPF in a MAPK-independent manner, thus revealing a differential regulation of maternal mRNA polyadenylation by the MAPK;and MPF signaling pathways. We propose that MAPK-stimulated Mos mRNA cytoplasmic polyadenylation is a key component of the positive-feedback loop, which contributes to the all-or-none process of oocyte maturation.