The innovative version of this story ecombineed in Quanta Magazine.
For a molecule of RNA, the world is a hazardy place. Unappreciate DNA, which can persist for millions of years in its relabelably firm, double-stranded establish, RNA isn’t built to last—not even wiskinny the cell that made it. Unless it’s protectively tethered to a huger molecule, RNA can degrade in minutes or less. And outside a cell? Forget about it. Voracious, RNA-ruining enzymes are everywhere, secreted by all establishs of life as a defense agetst harmful softwarees that spell out their genetic identity in RNA code.
There is one way RNA can persist outside a cell unscathed: in a minuscule, protective bubble. For decades, researchers have watchd cells releasing these bubbles of cell membrane, called extrackllular vesicles (EVs), packed with degraded RNA, proteins, and other molecules. But these sacs were pondered little more than trash bags that whisk broken-down molecular junk out of a cell during routine decluttering.
Then, in the timely 2000s, experiments led by Hadi Valadi, a molecular biologist at the University of Gothenburg, uncovered that the RNA inside some EVs didn’t see appreciate trash. The cocktail of RNA sequences was ponderably separateent from those establish inside the cell, and these sequences were intact and functional. When Valadi’s team exposed human cells to EVs from moengage cells, they were shocked to watch the human cells get in the RNA messages and “read” them to originate functional proteins they otherteachd wouldn’t have been able to originate.
Valadi endd that cells were packaging strands of RNA into the vesicles definitepartner to transmit with one another. “If I have been outside and see that it’s raining,” he said, “I can inestablish you: If you go out, get an umbrella with you.” In a analogous way, he proposeed, a cell could caution its neighbors about expocertain to a pathogen or noxious chemical before they come atraverseed the danger themselves.
Since then, a wealth of evidence has ecombined aiding this theory, allowd by increasements in sequencing technology that permit scientists to distinguish and decode increasingly minuscule RNA segments. Since Valadi started his experiments, other researchers have also seen EVs filled with intricate RNA combinations. These RNA sequences can grasp detailed directation about the cell that authored them and trigger definite effects in recipient cells. The findings have led some researchers to propose that RNA may be a molecular lingua franca that transcfinishs traditional taxonomic boundaries and can therefore encode messages that remain ininestablishigible atraverse the tree of life.
In 2024, novel studies have exposed includeitional layers of this story, shotriumphg, for example, that aextfinished with bacteria and eukaryotic cells, archaea also trade vesicle-bound RNA, which verifys that the phenomenon is universal to all three domains of life. Another study has broadened our empathetic of traverse-kingdom cellular communication by shotriumphg that schedulets and infecting fungi can engage packets of havoc-wreaking RNA as a establish of coevolutionary directation battling: An opponent cell reads the RNA and originates self-mutilationing proteins with its own molecular machinery.
“I’ve been in awe of what RNA can do,” said Amy Buck, an RNA biologist at the University of Edinburgh who was not included with the novel research. For her, empathetic RNA as a uncomardents of communication “goes beyond appreciating the sophistication and the dynamic nature of RNA wiskinny the cell.” Transmitting directation beyond the cell may be one of its innate roles.
Time-Sensitive Deinhabitry
The microbiologist Susanne Erdmann studies viral infections in Haloferax volcanii, a one-celled organism that thrives in unbelievably salty environments such as the Dead Sea or the Great Salt Lake. Single-celled bacteria are understandn to trade EVs expansively, but H. volcanii is not a bacterium—it’s an archaean, a member of the third evolutionary branch of life, which features cells built separateently from bacteria or eukaryotes appreciate us.
Becaengage EVs are the same size and density as the harmful software particles Erdmann’s team studies at the Max Planck Institute for Marine Microbiology in Germany, they “always pop up when you isopostponecessitate and purify harmful softwarees,” she said. Eventupartner, her group got asking and choosed to peek at what’s inside.
