4.26.2007

Micro RNAs: The Last Frontier of Medicine?

Micro RNAs: The Last Frontier of Medicine?: "Micro RNAs (miRNA) were discovered in worms about 14 years ago, but they have been found in a wide range of organisms (including humans) in the last few years. A subset of our genes encode miRNAs which are transcribed in the usual fashion creating primary transcripts (pri-miRNA). These long single stranded pri-miRNAs fold back on themselves to create hairpin stem-loop structures. The hairpins in the pri-miRNA are cleaved into short 70 nucleotide pre-miRNAs through drosha processing. These Pre-miRNAs are then exported from the nucleus. In the cytoplasm, dicer processing takes place where the RNA-induced silencing complex (RISC) binds to the hairpin RNAs and further cuts the RNA to make the final miRNA."