RNA biology
-
MicroRNAs (miRNAs) are important players of post-transcriptional gene regulation. Individual miRNAs can target multiple mRNAs and a single mRNA can be targeted by many miRNAs. We hypothesized that miRNAs select and regulate their targets based on their own expression levels, those of their target mRNAs and triggered feedback loops. ⋯ These findings were supported by gene modulation studies using endogenous levels of miR-29, -1 and -206 and a luciferase reporter system in multiple cell lines. Finally, we determined that the miR-17-92 cluster affected cell viability in a dose-dependent manner. In conclusion, we have shown that miRNAs potentially select their targets in a dose-dependent and nonlinear fashion that affects biological function; and this represents a novel mechanism by which miRNAs orchestrate the finely tuned balance of cell function.