Biochemical controls: intracellular communication (Introduction)

by David Turell , Monday, September 16, 2024, 19:32 (66 days ago) @ David Turell

Using RNA's:

https://www.quantamagazine.org/cells-across-the-tree-of-life-exchange-text-messages-usi...

"RNA isn’t built to last — not even within the cell that made it. Unless it’s protectively tethered to a larger molecule, RNA can degrade in minutes or less. And outside a cell? Forget about it. Voracious, RNA-destroying enzymes are everywhere, secreted by all forms of life as a defense against viruses that spell out their genetic identity in RNA code. There is one way RNA can survive outside a cell unscathed: in a tiny, protective bubble. For decades, researchers have noticed cells releasing these bubbles of cell membrane, called extracellular vesicles (EVs), packed with degraded RNA, proteins and other molecules. But these sacs were considered little more than trash bags that whisk broken-down molecular junk out of a cell during routine decluttering.

"Then, in the early 2000s, experiments led by Hadi Valadi, a molecular biologist at the University of Gothenburg, revealed that the RNA inside some EVs didn’t look like trash. The cocktail of RNA sequences was considerably different from those found inside the cell, and these sequences were intact and functional. When Valadi’s team exposed human cells to EVs from mouse cells, they were shocked to observe the human cells take in the RNA messages and “read” them to create functional proteins they otherwise wouldn’t have been able to make.

"Since then, a wealth of evidence has emerged supporting this theory, enabled by improvements in sequencing technology that allow scientists to detect and decode increasingly small RNA segments. Since Valadi published his experiments, other researchers have also seen EVs filled with complex RNA combinations. These RNA sequences can contain detailed information about the cell that authored them and trigger specific effects in recipient cells. The findings have led some researchers to suggest that RNA may be a molecular lingua franca that transcends traditional taxonomic boundaries and can therefore encode messages that remain
intelligible across the tree of life.

"In 2024, new studies have exposed additional layers of this story, showing, for example, that along with bacteria and eukaryotic cells, archaea also exchange vesicle-bound RNA, which confirms that the phenomenon is universal to all three domains of life. Another study has expanded our understanding of cross-kingdom cellular communication by showing that plants and infecting fungi can use packets of havoc-wreaking RNA as a form of coevolutionary information warfare: An enemy cell reads the RNA and builds selfharming proteins with its own molecular
machinery.

***

"How can RNA from one branch of the tree of life be understood by organisms on another? It’s a common language, Buck said. RNA has most likely been around since the very beginning of life. While organisms have evolved and diversified, their RNA-reading machinery has largely stayed the same. “RNA already has a meaning in every cell, ” Buck said.
“And it’s a pretty simple code.”

Comment: the comment above makes perfect sense. Life is built from a small initial common background. RNA is a small perfect messenger.