Nucleoli and Promyelocytic Leukemia Protein (PML) bodies are phase separated nuclear protein quality control compartments for misfolded proteins.

We uncovered a role for nucleoli and PML-bodies as phase-separated protein quality control organelles that compartmentalize protein quality control factors and misfolded proteins for their efficient clearance. Failure to dispose misfolded proteins converts nucleoli and PML-bodies into a solid state that immobilizes ubiquitin, limiting its recycling for genome integrity maintenance.