DICER: structure, function, and regulation.

Regulation of gene expression by small non-coding RNAs, such as miRNAs and siRNAs, is an inherent part of complex biological processes that allow function and survival of eukaryotic cells. The type III ribonuclease DICER is widely recognized as a key step in the production of miRNAs and siRNAs, although it also has non-canonical functions such as DNA repair and induction of apoptosis. DICER is at the cornerstone of most biological processes; hence, its mRNA and protein levels are subject to multiple layers of regulation. Accordingly, DICER derangement is related to disease and leads to accelerated aging. Interventions that boost DICER function hold great potential as strategies to promote health and longevity. In this review, we will summarize the structural features of DICER, describe its canonical and non-canonical roles, and discuss the most common regulatory mechanisms having an impact on DICER abundance and function. We will also touch upon the current literature demonstrating that DICER deregulation can lead to diseases, thus highlighting the importance of DICER in warranting the beneficial effects of health-promoting interventions.