fig1
From: The role of circRNAs and miRNAs in drug resistance and targeted therapy responses in breast cancer
Figure 1. Biogenesis and functional mechanism of miRNA. MiRNA is transcribed from DNA into primary miRNA (pri-miRNA) transcripts by RNA polymerase II or III in the cell nucleus. Subsequently, pri-miRNA is cleaved into precursor miRNA (pre-miRNA). Under the regulation of RanGTP protein, pre-miRNA is transported to the cytoplasm through the shuttle protein exportin 5. After entering the cytoplasm, Dicer RNase catalyzes the cleavage of pre-miRNA into mature double-stranded miRNA. One of the miRNA single strands binds to RISC (also known as miRISC). RISC: RNA-induced silencing complex.
