PDF(Pubmed)
Abstract：
MicroRNAs (miRNAs) are small non-coding RNAs which contribute to the regulation of many physiological and pathological processes. Conventionally, miRNAs perform their activity in the cytoplasm where they regulate gene expression by interacting in a sequence-specific manner with mature messenger RNAs. Recent studies point to the presence of mature miRNAs in the nucleus. This review summarizes current findings regarding the molecular activities of nuclear miRNAs. These molecules can regulate gene expression at the transcriptional level by directly binding DNA on the promoter or the enhancer of regulated genes. miRNAs recruit different protein complexes to these regions, resulting in activation or repression of transcription, through a number of molecular mechanisms. Hematopoiesis is presented as a paradigmatic biological process whereby nuclear miRNAs possess a relevant regulatory role. Nuclear miRNAs can influence gene expression by affecting nuclear mRNA processing and by regulating pri-miRNA maturation, thus impacting the biogenesis of miRNAs themselves. Overall, nuclear miRNAs are biologically active molecules that can be critical for the fine tuning of gene expression and deserve further studies in a number of physiological and pathological conditions.
摘要：
MicroRNAs(miRNAs)是一种小的非编码RNA,参与许多生理和病理过程的调控。传统上,miRNA在细胞质中发挥其活性,在细胞质中它们通过以序列特异性方式与成熟信使RNA相互作用来调节基因表达。最近的研究指出在细胞核中存在成熟的miRNA。这篇综述总结了有关核miRNA分子活性的最新发现。这些分子可以通过将DNA直接结合在受调节基因的启动子或增强子上来在转录水平上调节基因表达。miRNAs招募不同的蛋白质复合物到这些区域，导致转录的激活或抑制，通过多种分子机制。造血被呈现为范例性的生物过程,其中核miRNA具有相关的调节作用。核miRNA可以通过影响核mRNA加工和调节pri-miRNA成熟来影响基因表达,从而影响miRNAs本身的生物发生。总的来说,核miRNAs是生物活性分子，对基因表达的微调至关重要，值得在许多生理和病理条件下进一步研究。
