Behind every big biomedical breakthrough lies boatloads of basic biology. In that vein, a new finding published today in Cell shakes up a fundamental view of RNA, the bridging material necessary to convert genes into proteins.
Previously, it was well known that RNA is degraded, broken down into its constituent parts so it could be used again. Otherwise, used RNA would accumulate in the cell, clogging it up. But everyone assumed that RNA was degraded only after it had transmitted its message to build a protein.
Now, a team of researchers led by Lars Steinmetz, PhD, professor of genetics, have discovered that RNA is broken down while it's communicating the blueprint for protein assembly, a process known as translation. One end of the RNA is still making proteins while the other is being dismantled.
"In the bigger picture, decaying RNA was thought to be of little interest biologically," Steinmetz said. "Our findings show that it contains hallmarks of the translation process."
That finding could change the way researchers examine gene expression in live cells. Current methods use drugs that "freeze" the translation process, but that artificial interference alters the measurements of protein creation. A new method — which involves looking at the products of the RNA degradation — simplifies that process and produces more accurate results, said Wu Wei, PhD, a senior research scientist in biochemistry who worked on the research.
"People think that RNA is translated or degraded, but actually they can happen at the same time," Wei said.
The researchers made the discovery almost accidently, when they spotted an unusual pattern in the byproducts of RNA that remained in the cell.
So far, their work has been in living yeast cells, but Wei said the team plans to move next to examining RNA degradation in human cells.
"Our approach provides a simple and straightforward way to measure ribosome dynamics in living cells. Both this study and research performed by our collaberators have proven that it is a powerful tool to investigate the regulation of translation, said Vicent Pelechano, PhD, who is based in Steinmetz's laboratory at the European Molecular Biology Laboratory and designed the experimental aspects of the study.
Previously: The politics of destruction: Short-lived RNA helps stem cells turn on a dime, Step away from DNA? Circulating *RNA* in blood gives dynamic information about pregnancy, health and RNA Rosetta stone? Molecules' second, structural language predicted from their first, linear one
Image by AJ Cann