[Perspective] Disrupted nuclear import-export in neurodegeneration
The major human neurodegenerative diseases, including Alzheimer's, amyotrophic lateral sclerosis, Parkinson's, and Huntington's diseases, are associated with accumulation and aggregation of misfolded proteins. In most cases, the majority of aberrantly aggregated proteins are found in the cell cytoplasm. However, in disorders caused by the expansion of a trinucleotide repeat, including Huntington's disease and spinocerebellar ataxia, the corresponding aggregates of proteins containing the encoded polyglutamine expansions are predominantly nuclear. Whether differences in intracellular location matter for the toxicity generated by such proteins has not been determined. On page 173 of this issue, Woerner et al. (1) report that the location does indeed matter, with toxicity arising from the cytoplasmic accumulation of a pair of artificial proteins designed to mimic the properties of amyloid aggregates. Surprisingly, forcing the same artificial proteins into the nucleus substantially reduces their toxicity. Authors: Sandrine Da Cruz, Don W. Cleveland
