Disruption of nucleolar integrity triggers cellular quiescence through organelle rewiring and secretion

Summary The nucleolus is the largest membraneless nuclear organelle and a critical regulator of growth and stress responses, comprised of over 600 proteins involved in ribosome biogenesis. However, how the nucleolar function and architecture coordinate cell-wide adaptive programs remains unclear. Here, we combined multi-omics profiling with functional genomics to define the cellular consequences of nucleolar disruption. We identify a stress response pathway connecting the nu cleolus to the G olgi apparatus, e ndo-lysosomal trafficking, and cellular s ecretion (NuGETS). Chronic nucleolar defects activate a TP53-dependent transcriptional program that promotes organelle expansion, enhances secretory activity, and induces cell cycle exit with prolonged quiescence and partial epithelial-to-mesenchymal transition (pEMT) phenotypes. A genome-wide CRISPRi screen uncovered 400 regulators of secretory and quiescent states upon nucleolar stress. These pathways are enriched in cancer progression associated with ribosomopathies. Our findings therefore link nucleolar stress responses and cancer development, revealing cell-wide regulatory mechanisms that safeguard survival when nucleolar function is compromised.