PML as a neuroprotective guardian: Leveraging nuclear protein quality control to mitigate neurotoxicity of an ALS-associated NEK1 variant.

Insoluble protein aggregates are a hallmark of neurodegenerative diseases like amyotrophic lateral sclerosis (ALS). The ubiquitin-proteasome system (UPS) serves as a neuroprotective quality control mechanism that clears aggregates. PML nuclear bodies (NBs) were proposed to serve as hubs for SUMO-primed ubiquitylation and degradation of misfolded proteins. Georgiadou et al. provide evidence that an ALS-linked NEK1 truncation mutant is recruited to PML NBs, where it likely undergoes SUMOylation and ubiquitylation. In mice, PML loss exacerbates ALS-like symptoms, while induced PML expression delays disease onset. These findings establish PML as a key regulator of proteostasis and highlight PML induction as a potential therapeutic strategy for ALS and related proteinopathies.