Nucleolus: A Protein Quality Control Compartment.

Frottin et al. uncovered a role for the nucleolus as a key quality control compartment that regulates misfolded nuclear proteins. This nonmembrane compartment achieves this by forming liquid-like protein condensates that aid protein refolding in a heat-shock protein (Hsp)70-dependent manner. This liquid-liquid phase separation (LLPS)-mediated nuclear quality control mechanism is perturbed during neurodegeneration.