Evidence that microRNAs are associated with translating messenger RNAs in human cells

Abstract

MicroRNAs (miRNAs) regulate gene expression post-transcriptionally by binding the 3' untranslated regions of target mRNAs. We examined the subcellular distribution of three miRNAs in exponentially growing HeLa cells and found that the vast majority are associated with mRNAs in polysomes. Several lines of evidence indicate that most of these mRNAs, including a known miRNA-regulated target (KRAS mRNA), are actively being translated.