Liquid–liquid phase separation is thought to be a key organizing principle in eukaryotic cells to generate highly concentrated dynamic assemblies, such as the RNP granules. Numerous in vitro approaches have validated this model, yet a missing aspect is to take into consideration the complex molecular mixture and promiscuous interactions found in vivo. Here we report the versatile scaffold ArtiG to generate concentration-dependent RNA–protein condensates within living cells, as a bottom-up approach to study the impact of co-segregated endogenous components on phase separation. We demonstrate that intracellular RNA seeds the nucleation of the condensates, as it provides molecular cues to locally coordinate the formation of endogenous high-order RNP assemblies. Interestingly, the co-segregation of intracellular components ultimately impacts the size of the phase-separated condensates. Thus, RNA arises as an architectural element that can influence the composition and the morphological outcome of the condensate phases in an intracellular context.
Press release available :
Building artificial organelles to examine the formation of RNA-protein compartments
(in french : Utiliser des organelles artificielles pour examiner les transitions de phase contrôlant la formation des compartiments ARN-protéines)
RNA is a critical element for the sizing and the composition of phase-separated RNA-protein condensates
Marina Garcia-Jove Navarro, Shunnichi Kashida, Racha Chouaib, Sylvie Souquere, Gerard Pierron, Dominique Weil, Zoher Gueroui
DOI : 10.1038/s41467-019-11241-6