期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2011
卷号：108
期号：20
页码：8281-8286
DOI：10.1073/pnas.1105401108
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：MicroRNA-protein complexes (microRNPs) can activate translation of target reporters and specific mRNAs in quiescent (i.e., G0) mammalian cell lines. Induced quiescent cells, like folliculated immature oocytes, have high levels of cAMP that activate protein kinase AII (PKAII) to maintain G0 and immature states. We report microRNA-mediated up-regulated expression of reporters in immature Xenopus laevis oocytes, dependent on Xenopus AGO or human AGO2 and on FXR1, as in mammalian cells. Importantly, we find that maintenance of cAMP levels and downstream PKAII signaling are required for microRNA-mediated up-regulated expression in oocytes. We identify an important, endogenous cell state regulator, Myt1 kinase, as a natural target of microRNA-mediated up-regulation in response to xlmiR16, ensuring maintenance of oocyte immaturity. Our data reveal the physiological relevance of cAMP/PKAII-controlled posttranscriptional gene expression activation by microRNAs in maintenance of the immature oocyte state.
