Schematic overview of canonical miRNA biogenesis. The pri-miRNA is transcribed from intergenic or intronic region and subsequently spliced by microprocessors, namely, Drosha/DGCR8 or spliceosome. On export from the nucleus to cytosol via Exportin 5, the pre-miRNA is incorporated into RISC complex after Dicer cleavage. Being unwound in RISC complex, one strand stays in the RISC complex as the mature miRNA while the other strand undergoes degradation. Binding to target messenger RNA by miRNAs in RISC complex is followed by translation inhibition and/or mRNA degradation in the cytoplasm.
