Keywords:
Argonaute proteins,
RNA activation,
chromatin remodeling,
gene regulation,
promoter-targeting miRNAs,
transcriptional gene silencing
Abstract:
microRNAs (miRNAs), defined as 21–24 nucleotide non-coding RNAs, are important regulators of gene expression. Initially, the functions of miRNAs were recognized as post-transcriptional regulators on mRNAs that result in mRNA degradation and/or translational repression. It is becoming evident that miRNAs are not only restricted to function in the cytoplasm, they can also regulate gene expression in other cellular compartments by a spectrum of targeting mechanisms via coding regions, 5′ and 3′untransalated regions (UTRs), promoters, and gene termini. In this point-of-view, we will specifically focus on the nuclear functions of miRNAs and discuss examples of miRNA-directed transcriptional gene regulation identified in recent years.