Dicer ribonuclease III (DICER)

Dicer ribonuclease III (commonly called Dicer or DICER1) is a multidomain, magnesium-dependent endoribonuclease belonging to the RNase III family. Structurally, it contains a helicase domain, DUF283, a PAZ domain, a connector helix, two RNase III domains (IIIa and IIIb), and a C-terminal dsRNA-binding domain. Dicer functions as a molecular ruler, binding double-stranded RNA and cleaving these precursors into short fragments (typically 21–25 nucleotides) with a 2-nucleotide 3' overhang. This activity is central to the generation and maturation of microRNAs (miRNAs) and small interfering RNAs (siRNAs), enabling sequence-specific regulation of gene expression (RNA silencing). In humans, Dicer is encoded by the DICER1 gene, which is crucial for development, differentiation, antiviral defense, and prevents oncogenic transformation—loss or mutation can result in disease or promote cancer. Dicer is not a receptor, transporter, or channel; it is a catalytic enzyme essential for RNA processing.

Other names

DicerDICER1 (human gene name)Ribonuclease III DicerDicer enzymeRNase III Dicer

For drugs or therapeutics that modulate Dicer: inhibition or enhancement of dsRNA cleavage function, affecting production of miRNA/siRNA and downstream gene silencing. RNAi therapeutics: require Dicer activity to generate active siRNA/miRNA fragments for target mRNA silencing.