微小RNAs的3'端尿苷化和腺苷化

3' Uridylation and Adenylation of miRNAs

miRNA是转录后基因表达调节的重要分子,但目前对它们自身的调节机制还知之甚少.最近的研究发现,在很多生物中,miRNA的3'末端都可以无需模板的添加尿苷酸(尿苷化)或腺苷酸(腺苷化),这种修饰可以发生在miRNA的前体上,也可以发生在成熟的miRNA上,其作用不仅可以影响miRNA的生物合成,稳定性,靶向靶标mRNAs的效率,而且还可以作为损伤miRNA的质量控制机制,及其形成mRNAs的异构体,以提高miRNA的作用范围或更精细的发挥基因表达调节作用.越来越多的研究揭示:这种修饰具有miRNA、组织、生物发育阶段和疾病状况等特异性,而且还涉及很多人类的发病机制,如癌症.本文综述了miRNA的3'末端尿苷化或腺苷化的研究进展,并对这种机制的应用前景进行了展望.

miRNAs are post-transcriptional regulators of gene expression. It was recently discovered that non-templated addition of uridines or adenosines to miRNAs frequently occurred in many organisms, both of pre-miRNAs and mature miRNAs. The modifications of uridylation and adenylation not only influence miRNA biogenesis, stabilities and targeting efficiency, but also serve as a quality control mechanism for the degradation of damaged miRNAs. The produced miRNA variants expand the miRNA targeting repertoire and exhibit a fine-tune control of gene expression. Growing evidence has revealed that sueh modifications can be sequence-, or tissue- specific, and with dependency to certain developmental, or disease states. Progresses in the studies of miRNA 3＇ uridylation and adenylation, together with the application perspective, are discussed in this review