Cell doi:10.1016/j.cell.2010.06.040 (2010)

Geneticists have been puzzled by long RNA molecules that are made by mammalian genomes but do not code for protein. What, if anything, do they do? John Rinn and Maite Huarte at the Broad Institute in Cambridge, Massachusetts, and their colleagues report that one long non-coding RNA is important in a cell's response to the protein p53.

Best known as a tumour suppressor, p53 controls the transcription of many genes. The team showed that it also triggers the production of several long non-coding RNAs and that one of these, lincRNA-p21, stifles the expression of many genes further downstream in the p53 response pathway, and promotes cell suicide. It seems to do this by associating with a second protein, hnRNP-K. The authors propose that other proteins like p53 activate long non-coding RNAs that help to silence genes.