Highly read on www.cell.com 22 Jan–21 Feb

Long RNA molecules have recently been discovered that seem to regulate genes rather than code for proteins, but little is known about how they do this. Loss of a protective cap from these long noncoding RNAs (lncRNAs) seems to be a crucial step in regulating a specific type of gene in yeast.

Like protein-encoding messenger RNAs, lncRNAs have a cap that protects the molecule from decomposing. By preventing loss of the cap in budding yeast, Jeff Coller and his colleagues at Case Western Reserve University in Cleveland, Ohio, found that many lncRNAs function at genomic regions near highly regulated genes that respond to specific environmental cues such as sugars and iron. One family of these 'inducible' genes — the GAL system, which enables cells to metabolize a sugar called galactose — is regulated by lncRNAs that must lose their caps for the cell to activate the sugar-processing genes.

Mol. Cell 45, 279–291 (2012)