Document Type

Article

Publication Date

5-15-2015

Comments

This is the final published version of the article from the Journal of Biological Chemistry, 2015 May 15;290(20):12572-84.

The full text of the article can also be accessed at the journal's website: https://doi.org/10.1074/jbc.M114.617894

Abstract

Proteolysis of polyglutamine-expanded proteins is thought to be a required step in the pathogenesis of several neurodegenerative diseases. The accepted view for many polyglutamine proteins is that proteolysis of the mutant protein produces a "toxic fragment" that induces neuronal dysfunction and death in a soluble form; toxicity of the fragment is buffered by its incorporation into amyloid-like inclusions. In contrast to this view, we show that, in the polyglutamine disease spinal and bulbar muscular atrophy, proteolysis of the mutant androgen receptor (AR) is a late event. Immunocytochemical and biochemical analyses revealed that the mutant AR aggregates as a full-length protein, becoming proteolyzed to a smaller fragment through a process requiring the proteasome after it is incorporated into intranuclear inclusions. Moreover, the toxicity-predicting conformational antibody 3B5H10 bound to soluble full-length AR species but not to fragment-containing nuclear inclusions. These data suggest that the AR is toxic as a full-length protein, challenging the notion of polyglutamine protein fragment-associated toxicity by redefining the role of AR proteolysis in spinal and bulbar muscular atrophy pathogenesis.

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

PubMed ID

25795778

Language

English

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