Coding in non-coding RNAs

摘要

In plants and animals, microRNAs regulate the expression of many different genes. Such regulation is crucial in a variety of processes, including transitions through developmental stages and responses to environmental stresses. MicroRNAs (miRNAs) are short in sequence and are generated by enzymatic excision from precursor transcripts called primary miRNAs (pri-miRs), which until now had been assumed not to encode any proteins. But on page 90 of this issue, Lauressergues et al. provide convincing evidence to the contrary. They find that some pri-miRs encode peptides that enhance production of their miRNAs. This is the first report of a functional peptide being encoded by a pri-miR and provides a fresh perspective on the significance of pri-miR regions beyond those that directly give rise to miRNAs.