Figure 2.

The synthesis and biological function of miRNAs and lncRNAs. A. Precursor miRNA (pre-miRNA) is transported from the nucleus to the cytoplasm and cleaved by Dicer to produce the miRNA duplex. One strand of the duplex would be assembled into the miRNA-induced silencing complex (RISC) with the Argonaute protein and other co-factors. By base-pairings between miRNAs and their complementary sequences in the 3’-untranslated region (3′-UTR) of target mRNA, RISCs binds to the target mRNAs and suppresses its translation or induces its degradation to regulate the down-stream biological process. B. lncRNA regulates the biological processes of cells through four main mechanisms as described in the main text.