Parker Roy, Sheth Ujwal
Howard Hughes Medical Institute, University of Arizona, Tucson, AZ 85721, USA.
Mol Cell. 2007 Mar 9;25(5):635-46. doi: 10.1016/j.molcel.2007.02.011.
Recent results indicate that many untranslating mRNAs in somatic eukaryotic cells assemble into related mRNPs that accumulate in specific cytoplasmic foci referred to as P bodies. Transcripts associated with P body components can either be degraded or return to translation. Moreover, P bodies are also biochemically and functionally related to some maternal and neuronal mRNA granules. This suggests an emerging model of cytoplasmic mRNA function in which the rates of translation and degradation of mRNAs are influenced by a dynamic equilibrium between polysomes and the mRNPs seen in P bodies. Moreover, some mRNA-specific regulatory factors, including miRNAs and RISC, appear to repress translation and promote decay by recruiting P body components to individual mRNAs.
近期研究结果表明，在体细胞真核细胞中，许多未进行翻译的信使核糖核酸（mRNA）组装成相关的信使核糖核蛋白颗粒（mRNP），这些颗粒聚集在特定的细胞质区域，即所谓的P小体中。与P小体成分相关的转录本既可以被降解，也可以重新进入翻译过程。此外，P小体在生化和功能上还与一些母体和神经元mRNA颗粒相关。这提示了一种新出现的细胞质mRNA功能模型，即mRNA的翻译和降解速率受多核糖体与P小体中mRNP之间动态平衡的影响。此外，一些mRNA特异性调控因子，包括微小RNA（miRNA）和RNA诱导沉默复合体（RISC），似乎通过将P小体成分招募到单个mRNA上来抑制翻译并促进降解。
