RNA Interference

Synonyms

Knockdown; miRNA-induced deadenylation; miRNA-induced silencing; RNAi

Definition

RNA interference is the binding of small RNAs, called microRNAs (miRNA) or small interfering RNAs (siRNAs), to mRNAs, which triggers either translation repression or mRNA degradation of the target mRNA. If the miRNA/siRNA binds the mRNA with perfect complementarity, it will cause cleavage of the mRNA, which will trigger its degradation. If the miRNA binds the mRNA imperfectly, it will trigger either translation repression or deadenylation-dependent decay. It is estimated that between half to two thirds of human mRNAs are targets of RNAi, suggesting that miRNAs are a major source of regulation of gene expression.

Discussion

Proteins are not the only trans-factors that affect the function of individual mRNAs; small RNAs (miRNAs and siRNAs) can bind mRNAs through Watson-Crick base pairing to decrease their translation or stability. miRNAs are 21–23 nucleotide RNAs that bind cis elements in mRNAs...