MIWI/piRNA激活小鼠精子细胞mRNA翻译的新功能机制研究  

The Study of MIWI/piRNA-Mediated mRNA Translational Activation during Mouse Spermiogenesis

作　　者：戴鹏 刘默芳 DAI Peng;LIU Mofang(Center for Excellence in Molecular Cell Science,Institute of Biochemistry and Cell Biology,Shanghai Institutes of Biological Sciences,Chinese Academy of Sciences,Shanghai 200031,China)

机构地区：[1]中国科学院分子细胞科学卓越创新中心/生物化学与细胞生物学研究所,上海200031

出　　处：《中国细胞生物学学报》2020年第2期173-176,共4页Chinese Journal of Cell Biology

基　　金：科技部重大研发项目(批准号:2017YFA0504400)资助的课题。

摘　　要：哺乳动物减数分裂后期的精子发生(spermatogenesis),即精子形成(spermiogenesis),是一个剧烈的细胞形态变化过程。伴随精子细胞中细胞核压缩和染色质重构,基因转录活性将逐渐降低直至完全停止,那些为精子细胞后期阶段发育所需的基因都需要提前转录为信使核糖核酸(mRNA),然后以翻译抑制状态储存在精子细胞中,直到特定发育阶段再被激活翻译,以合成蛋白质发挥作用。这个现象被称为“转录–翻译解偶联”,是精子发生中基因表达调控的一个典型特征。然而,目前对于精子细胞中被抑制的mRNA是如何被翻译激活的还知之甚少。我们当前的这项研究发现,MIWI/piRNA通过与翻译起始因子eIF3f、RNA结合蛋白HuR等因子形成功能性翻译激活复合物,特异性地激活小鼠精子细胞中包含AU序列富含元件(AU-rich element,ARE)mRNA的翻译。此项研究揭示了PIWI/piRNA在精子细胞翻译激活中的新功能,并证明此功能为精子细胞发育和功能性精子生成所必需。Development of post-meiotic male germ cell cells in animals is known as a complex biochemical and morphological process,which is termed as spermiogenesis.Chromatin condensation results in a drastic inhibition of transcriptional activity in late stages of haploid spermatids,and genes that are required for spermiogenesis need to be transcribed in advance and stored as mRNAs in earlier stages of germ cells.However,it remains largely unclear how such repressed mRNAs become activated during spermiogenesis.Here,we unexpectedly discovered that MIWI/piRNA/eIF3f/HuR super-complex is responsible for activating translation of a subset of spermiogenic mRNAs containing cis-acting AU-rich elements.These findings reveal a critical role of the PIWI/piRNA in translation activation,which is functionally required for spermatid development.

关 键 词：PIWI MIWI PIRNA eIF3f HUR 翻译激活 精子形成 

分 类 号：Q75[生物学—分子生物学]