Dynamic miRNA–mRNA paradigms: New faces of miRNAs

• miRNA–mRNA interactions which could take place in different cellular locations.
• miRNA binding sites included not only 3′UTRs, but also 5′UTRs and CDSs.
• miRNAs could switch from translational inhibition to activation.

More and more evidences suggested that the flow of genetic information can be spatially and temporally regulated by non-coding RNAs (ncRNAs), such as microRNAs (miRNAs). Although biogenesis and function of miRNAs have been well detailed, elucidation of the dynamic interplays between miRNAs and mRNAs have just begun. Here, we highlighted that the miRNA–mRNA interactions which could take place in different cellular locations. During dynamic interactions, miRNA binding sites included not only 3′UTRs, but also 5′UTRs and CDSs. Under different physiological or pathological conditions, miRNAs could switch from translational inhibition to activation. Dynamic miRNA–mRNA paradigms which suggested a novel tip of the iceberg beneath the gene regulation network will provide clues for function studies of other ncRNAs.