Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, 2-39-1, Kurokami, Kumamoto 860-8555, Japan.
Front Biosci (Landmark Ed). 2012 Jan 1;17(4):1402-17. doi: 10.2741/3994.
Recent genome-wide analyses revealed that eukaryotic genomes are almost entirely transcribed, generating a large number of short or long non-protein coding RNAs (non-coding RNAs; ncRNAs). Rapidly accumulating experimental evidence suggests that ncRNAs are not just transcriptional noise, but have biological roles in gene expression. In this review, we focus on the functions of nuclear-localized ncRNAs including the spliceosomal small nuclear RNAs. These nuclear ncRNAs play diverse regulatory roles in a wide-range of nuclear reactions, such as transcription, precursor-mRNA (pre-mRNA) splicing, nuclear structure formation, nuclear trafficking, and chromatin remodeling. The regulatory functions of ncRNAs in these reactions are reinforced by target-site recognition through base-pairing or formation of an RNA/DNA triple helix. Recent studies revealed an unexpected linkage between the machineries for RNA interference (RNAi)-mediated gene silencing and pre-mRNA splicing. In addition, the biogenesis of some ncRNAs was found to overlap with the pathway of pre-mRNA splicing. Our understanding of the mechanisms of coordinated gene regulation in the nucleus has increased dramatically through studies on nuclear ncRNAs. A new paradigm of "ncRNA regulation" is now emerging.
最近的全基因组分析表明，真核生物基因组几乎完全转录，产生了大量的短或长非蛋白编码 RNA（非编码 RNA；ncRNAs）。越来越多的实验证据表明，ncRNAs 不仅仅是转录噪音，而且在基因表达中具有生物学功能。在这篇综述中，我们重点介绍了核定位 ncRNAs 的功能，包括剪接体小核 RNA。这些核 ncRNAs 在广泛的核反应中发挥着多样化的调节作用，如转录、前体 mRNA（pre-mRNA）剪接、核结构形成、核运输和染色质重塑。ncRNAs 通过碱基配对或形成 RNA/DNA 三螺旋来识别靶位点，从而增强了在这些反应中的调节功能。最近的研究揭示了 RNA 干扰（RNAi）介导的基因沉默和 pre-mRNA 剪接的机器之间出乎意料的联系。此外，一些 ncRNAs 的生物发生被发现与 pre-mRNA 剪接途径重叠。通过对核 ncRNAs 的研究，我们对核内协调基因调控的机制有了显著的了解。一种新的“ncRNA 调控”范式正在出现。
