The role of the nuclear pore complex in the stability of disease-related short tandem DNA repeats

Nuclear pore complexes (NPCs) mediate selective transport between the nucleus and the cytoplasm but also contribute to maintaining genome stability. Mutations in NPC genes cause genome instability and sensitivity to DNA-damaging agents, and DNA that is difficult to repair or replicate relocates to NPCs, including expanded CAG repeats, which are associated with several neurological diseases. Here, we show that other disease-related short tandem repeats also relocate to NPCs. Relocation depends on the NPC basket protein Nup1, but is independent of the rest of the basket. Abrogating relocation to the NPC increases rates of repeat contraction, but not expansion. By contrast, deletion of the basket component NUP60, which causes mislocalization of all other basket proteins except Nup1, results in greater sensitivity to DNA-damaging agents and a higher rate of gross chromosomal rearrangement without affecting relocation to NPCs. Our results show that NPC association is a general feature of disease-related short tandem repeats, and suggest that relocation to NPCs is separable from the other genome maintenance functions of the NPC basket.