FIGURE 1.

Overview of miRNA biogenesis. (1) Genomically‐encoded miRNAs are transcribed within the nucleus and form a stem‐loop structure that is (2) processed by the Microprocessor complex comprising Drosha and DGCR8/Pasha. (3) The processed miRNA is then transferred to the cytoplasm through Exportin‐5 (XPO5). (4) The stem‐loop precursor miRNA is processed again by Dicer to remove the loop, and the miRNA duplex is loaded into an Argonaute protein. (5) The guide strand of the miRNA duplex is selected for loading into Argonaute to form the miRNA‐induced silencing complex (miRISC), while (5′) the other passenger strand is ejected from the Argonaute and degraded. (6) The miRISC targets mRNAs for silencing based on the seed sequence of the loaded miRNA guide strand