Nuclear RNA transcript levels modulate nucleocytoplasmic distribution of ALS/FTD-associated protein FUS.

Fused in Sarcoma (FUS) is a nuclear RNA/DNA binding protein that mislocalizes to the cytoplasm in the neurodegenerative diseases ALS and FTD. Despite the existence of FUS pathogenic mutations that result in nuclear import defects, a subset of ALS/FTD patients display cytoplasmic accumulation of wild-type FUS, although the underlying mechanism is unclear. Here we confirm that transcriptional inhibition, specifically of RNA polymerase II (RNAP II), induces FUS cytoplasmic translocation, but we show that several other stresses do not.