Long Noncoding RNAs Promote Transcriptional Poising of Inducible Genes

Long noncoding RNAs (lncRNAs) are a recently identified class of molecules that regulate the expression of protein-coding genes through a number of mechanisms, some of them poorly characterized. The GAL gene cluster of the yeast Saccharomyces cerevisiae encodes a series of three inducible genes that are turned on or off by the presence or absence of specific carbon sources in the environment. Previous studies have documented the presence of two lncRNAs—GAL10 and GAL10s—encoded by genes that overlap the GAL cluster.

Researchers at Purdue University have now uncovered a role for both these lncRNAs in promoting the activation of the GAL genes when they are released from repressive conditions. This activation occurs at the kinetic level, through more rapid recruitment of RNA polymerase II and decreased association of the co-repressor, Cyc8. Under normal conditions, but also especially when they are stabilized and their levels are up-regulated, these GAL lncRNAs promote faster GAL gene activation. The researchers suggest that these lncRNA molecules poise inducible genes for quick response to extracellular cues, triggering a faster switch in transcriptional programs.

• Cloutier SC, Wang S, Ma WK, Petell CJ, Tran EJ (2013) Long Noncoding RNAs Promote Transcriptional Poising of Inducible Genes. PLoS Biol 11(11), e1001715. [article]