Researchers at Caltech have discovered how an abundant class of RNA genes, called long non-coding RNAs (lncRNAs, pronounced link RNAs) can regulate key genes. By studying an important lncRNA, called Xist, the scientists identified how this RNA gathers a group of proteins and ultimately prevents women from having an extra functional X-chromosome–a condition in female embryos that leads to death in early development. These findings mark the first time that researchers have uncovered the detailed mechanism of action for lncRNA genes.
“For years, we thought about genes as just DNA sequences that encode proteins, but those genes only make up about 1 percent of the genome. Mammalian genomes also encode many thousands of lncRNAs,” says Assistant Professor of Biology Mitch Guttman, who led the study published online in the April 27 issue of the journal Nature. These lncRNAs such as Xist play a structural role, acting to scaffold–or bring together and organize–the key proteins involved in cellular and molecular processes, such as gene expression and stem cell differentiation.