Figure 1
From: MicroRNAs in inflammatory lung disease - master regulators or target practice?
Representation of miRNA induction and biogenesis. Induction of miRNA expression occurs via transcription factors and other regulatory influences. Primary miRNA transcripts (pri-miRNA) produced in the nucleus are generally processed by Drosha and DGCR8 into pre-miRNA hairpin structures and transported to the cytoplasm by Exportin 5. The pre-miRNA is processed by Dicer into a miRNA duplex where the mature miRNA guide strand is incorporated into a miRNA-induced silencing complex (miRISC) and the miRNA* strand is degraded. Incorporation into miRISC is facilitated by AGO proteins. Importin 8 aids subsequent transport of the miRNA to the target mRNA where binding to the 3'UTR occurs resulting in translational repression or degradation.