A leukemia-derived ENL/AF9 chemical probe enhances neuronal stress resilience and ameliorates ALS phenotypes

SUMMARY Chemical perturbation of chromatin reader proteins provides a precise strategy to interrogate epigenetic control of neuronal stress adaptation. ENL and AF9 are YEATS-domain acyl-lysine readers best characterized in leukemia, but their roles in neurons remain unclear. Here, we use the selective YEATS inhibitor SR-0813 to define ENL/AF9 function in neuronal stress responses across Drosophila and human systems. SR-0813 phenocopies genetic ENL/AF9 reduction by extending lifespan and enhancing stress tolerance in vivo, and improves survival of human neurons under multiple stress conditions, with the strongest effects during endoplasmic reticulum stress. Mechanistically, SR-0813 attenuates PERK-ISR signaling and reduces apoptotic commitment without broadly enhancing proteostasis capacity. Notably, its effects are highly context dependent, conferring protection in stress-signaling-driven models but reduced efficacy or detrimental outcomes under chronic aggregation or mitochondrial stress. These findings identify ENL/AF9 as modulators of stress-response dynamics and highlight YEATS-domain inhibition as a context-dependent strategy to reshape neuronal resilience. GRAPHICAL ABSTRACTsiRNA or the YEATS-domain inhibitor SR-0813 suppress the acyl-lysine reader ENL/AF9, extending lifespan and increasing H₂O₂ tolerance in Drosophila. In neurons (Drosophila and SH-SY5Y), ENL/AF9 inhibition lowers PERK–ISR signaling and apoptosis while maintaining proteostasis. Effects are context dependent: protective under UPR/ISR-dominant stress but potentially detrimental under aggregation or mitochondrial stress. Created with BioRender. Competing Interest Statement The authors have declared no competing interest. Footnotes ↵5 Lead contact We have made minor revisions to the manuscript, including correcting an author name and updating the funding information.