Lo Piccolo, L.; Panto, C.; Yeewa, R.; Yubolphan, R.; Potikanond, S.; JANTRAPIROM, S. O.

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.