Protein concentrations are tightly regulated in cells. This regulation is essential for cells to deal with environmental stress and is commonly deregulated in disease. MicroRNAs are master regulators of cellular protein levels by tuning-down the cytoplasmic protein production machinery. However, it is known that a subset of microRNAs is predominantly found in the nucleus with unknown functions. We recently discovered unexpected activities of these microRNAs at the level of protein upregulation, which is against the current dogma of microRNA biology.
We expect to unravel the role of nuclear miRNAs in mammalian cells.