gms | German Medical Science


Figure 1: Maturation of vertebrate miRNAs is a multi-step process.

In the first step, an up to 1,000 nucleotides long RNA molecule is transcribed from DNA. It forms a double-stranded stem loop and shows typical mRNA attributes. After further processing of this ‘primary transcript’, a mature miRNA of 19 to 23 nucleotides is generated. It performs its task as a component of the RNA-induced silencing complex (RISC). RISC-bound mRNAs remain untranslated resulting in reduced production of the encoded protein [9].