In response to stress, human cells coordinately downregulate transcription and translation of housekeeping genes. To downregulate transcription, the negative elongation factor (NELF) is recruited to gene promoters impairing RNA polymerase II elongation. Here we report that NELF rapidly forms nuclear condensates upon stress in human cells. Condensate formation requires NELF dephosphorylation and SUMOylation induced by stress. The intrinsically disordered region (IDR) in NELFA is necessary for nuclear NELF condensation and can be functionally replaced by the IDR of FUS or EWSR1 protein. We find that biomolecular condensation facilitates enhanced recruitment of NELF to promoters upon stress to drive transcriptional downregulation. Importantly, NELF condensation is required for cellular viability under stressful conditions. We propose that stress-induced NELF condensates reported here are nuclear counterparts of cytosolic stress granules. These two stress-inducible condensates may drive the coordinated downregulation of transcription and translation, likely forming a critical node of the stress survival strategy.

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 t rafficking, 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.