Membraneless organelles: a smart design for metabolic control

While most organelles are surrounded by membranes, cells also contain membraneless organelles, which remain separated in the cell by avoiding the mixture of their components with the surroundings. Actually, liquid-liquid phase separation provides a simple but smart mechanism for the cell to control the spatial localization and processing of molecules, without relying on membrane boundaries. This Special 'In the Limelight' section, entitled 'Membraneless organelles', consists of three review articles, each focused on a particular aspect. The first article deals with assembly of coacervates as mediated by polyproline II helices, as well as with condensate stability. The second article addresses the formation of protein-nucleic acid coacervates by prion-like proteins and their link to human diseases. Finally, the last article focuses on mitochondrial cytochrome c translocation into the nucleus after DNA damage, with the subsequent inhibition of nucleosome assembly/disassembly activity of histone chaperones and its impact on chromatin dynamics and nuclear condensates.