MiR-3120 is a mirror microRNA that targets heat shock cognate protein 70 and auxilin messenger RNAs and regulates clathrin vesicle uncoating

We show that a single gene locus gives rise to two fully processed and functional miRNAs i.e. that due to imperfect base pairing two distinct miRNAs can be produced from the fully complementary DNA strands. The anti-sense strand encodes miR-214, which is transcribed by its own promoter, while a novel miRNA, miR-3120, is coexpressed with its host-gene mRNA. We also found that miR-3120 regulates important aspects of cellular function that are similar to that of its host gene, dynamin-3: miR-3120 was found to be located in neuronal cell bodies, target Hsc70 and auxilin and its lentiviral mediated expression inhibited the uncoating of clathrin coated vesicles. Finally, mirror-miRNAs are likely to represent a new group of miRNAs with complex roles in coordinating gene expression.