title: Nuclear microRNAs and their unconventional role in regulating non-coding RNAs.
abstract: MicroRNAs (miRNAs) are small non-coding RNAs (ncRNAs) that are involved in post-transcriptional gene regulation. It has long been assumed that miRNAs exert their roles only in the cytoplasm, where they recognize their target protein-coding messenger RNAs (mRNAs), and result in translational repression or target mRNA degradation. Recent studies, however, have revealed that mature miRNAs can also be transported from the cytoplasm to the nucleus and that these nuclear miRNAs can function in an unconventional manner to regulate the biogenesis and functions of ncRNAs (including miRNAs and long ncRNAs), adding a new layer of complexity to our understanding of gene regulation. In this review, we summarize recent literature on the working model of these unconventional miRNAs and speculate on their biological significance. We have every reason to believe that these novel models of miRNA function will become a major research topic in gene regulation in eukaryotes.
authors.affiliation: Jiangsu Engineering Research Center for microRNA Biology and Biotechnology, State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, China.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Liang
authors.forename: Junfeng
authors.initials: J
authors.lastname: Zhang
authors.forename: Ke
authors.initials: K
authors.lastname: Zen
authors.forename: Chen-Yu
authors.initials: CY
authors.lastname: Zhang
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
mesh_terms: D002467:Cell Nucleus / Q000235:genetics; D003593:Cytoplasm / Q000235:genetics; D056890:Eukaryota / Q000235:genetics*; D005786:Gene Expression Regulation; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D020871:RNA Stability / Q000235:genetics; D062085:RNA, Long Noncoding / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D035683:MicroRNAs; D062085:RNA, Long Noncoding; D012333:RNA, Messenger