Fundamental Research Division
The DRF at the CEA assemble approximately 6,000 scientists since January 2016.
Scientific result | Fundamental Research | Cytoskeleton
The chemical structure of microtubules varies. But what is the relationship between the biochemical variations in these tubes and their mechanical properties? "We developed a microfluidic tool for the in vitro measurement of microtubule plasticity," said Manuel Théry, Laboratory Director at CEA-BIG. "Stabilizing the chemical features of microtubules gives us a chance to answer this question." Such was the method that the scientists chose, in partnership with peers from Stanford University who discovered an enzyme adding groups of five atoms to tubulins (the filaments constituting the microtubules) by acetylation. "This acetylation is preserved in many species," Théry said. "Since nature only keeps useful features, we can only guess that this acetylation must play an essential role." Using their microfluidic tool to observe the acetylated microtubules, the researchers revealed that this chemical transformation actually turns what can be seen as an oak... into a reed.
How is this possible? "Acetylation may act as a lubricant by allowing the 13 filaments that constitute the wall of the microtubules to shift and pile up on top of each other, thus relaxing the stress," Théry said. This raises another question: how is the enzyme responsible for acetylation recruited when the microtubules need to soften? "For now, we are only at the stage of hypotheses," Théry reckoned. "We think that when the tube folds, there might be an opening in the wall through which the enzymes can cross to acetylate the filaments, allowing them to soften instead of break under stress. This 'respiration' of microtubules would be a cycle combining biochemical and mechanical mechanisms." Now the scientists are trying to prove it.
Tubulin acetylation protects long-lived microtubules against mechanical ageing | Nature cell biology
Microtubules acquire resistance from mechanical breakage through intralumenal acetylation | Science
CEA is a French government-funded technological research organisation in four main areas: low-carbon energies, defense and security, information technologies and health technologies. A prominent player in the European Research Area, it is involved in setting up collaborative projects with many partners around the world.