State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Key Laboratory of Molecular Andrology, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 200031, China.
Key Laboratory of Computational Biology, CAS Center for Excellence in Brain Science and Intelligence Technology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 200031, China.
Trends Cell Biol. 2017 Jul;27(7):480-490. doi: 10.1016/j.tcb.2017.01.002. Epub 2017 Feb 10.
Alu elements belong to the primate-specific SINE family of retrotransposons and constitute almost 11% of the human genome. Alus are transcribed by RNA polymerase (Pol) III and are inserted back into the genome with the help of autonomous LINE retroelements. Since Alu elements are preferentially located near to or within gene-rich regions, they can affect gene expression by distinct mechanisms of action at both DNA and RNA levels. In this review we focus on recent advances of how Alu elements are pervasively involved in gene regulation. We discuss the impacts of Alu DNA sequences that are in close proximity to genes, Pol-III-transcribed free Alu RNAs, and Pol-II-transcribed Alu RNAs that are embedded within coding or noncoding RNA transcripts. The recent elucidation of Alu functions reveals previously underestimated roles of these selfish or junk DNA sequences in the human genome.
Alu 元件属于灵长类动物特异性的 SINE 家族反转录转座子，约占人类基因组的 11%。Alu 元件由 RNA 聚合酶（Pol）III 转录，并在自主的 LINE 反转录元件的帮助下插入基因组。由于 Alu 元件优先位于基因丰富区域附近或其中，因此它们可以通过在 DNA 和 RNA 水平上的不同作用机制影响基因表达。在这篇综述中，我们重点介绍了 Alu 元件如何广泛参与基因调控的最新进展。我们讨论了与基因紧密相邻的 Alu DNA 序列、Pol-III 转录的游离 Alu RNA 以及嵌在编码或非编码 RNA 转录本中的 Pol-II 转录的 Alu RNA 的影响。Alu 功能的最新阐明揭示了这些自私或垃圾 DNA 序列在人类基因组中以前被低估的作用。
