Figure 2. SiRNAs mechanism of action.
The RNA-interference mediated knockdown of gene expression in mammalian cells is based on the introduction of synthetic double-stranded siRNAs or plasmid and viral vector systems expressing double-stranded short hairpin RNAs (shRNAs) that are processed by the cellular machinery into siRNAs. Once loaded into Argonaute 2 (Ago2), the guide strand is incorporated in the RNA-induced silencing complex (RISC), leading to a sequence-specific degradation of complementary target mRNAs.