Figure 3.

Known examples for equilibrium binding competition affecting biological function. During RNA silencing (A), an activated RISC (dark blue oval) recognizes a miRNA response element (MRE, cyan rectangle) on an mRNA to downregulate its expression (red arrow). Upon expression of a significant concentration of an mRNA with an MRE of higher affinity (dark blue rectangle), or of a circular RNA with multiple MREs, a targeted mRNA will seemingly be upregulated (green arrow) due to the shifting coupled equilibrium siphoning off the limiting RISC (B).