C9orf72 ALS-causing mutations lead to nucleoporin Nup107 aggregation and subsequent pathological changes

Amyotrophic lateral sclerosis (ALS) is a fatal disorder caused by motor neuron degeneration. Hexanucleotide repeat expansions in the C9orf72 gene, the most common genetic cause of ALS (C9-ALS), drive toxicity through different mechanisms. These pathological changes include alterations in stress granules (SGs), ribonucleoprotein complexes formed under stress conditions. Here, we show that G3BP1, a core component of SGs, aberrantly interacts with the nucleoporin Nup107 in motor neurons derived from patient iPSCs carrying C9orf72 mutations. Moreover, Nup107 colocalizes with SGs and aggregates in C9-ALS motor neurons. Notably, knockdown of the C. elegans ortholog of Nup107 alleviates ALS-associated phenotypes in worm models, including reduced lifespan and motility. Our findings provide insights into C9-ALS pathogenesis and identify Nup107 as a potential therapeutic target.