Amyloid-mediated sequestration of essential proteins contributes to mutant huntingtin toxicity in yeast.

Autor: Natalia V Kochneva-Pervukhova, Alexander I Alexandrov, Michael D Ter-Avanesyan
Jazyk: angličtina
Rok vydání: 2012
Předmět:
Zdroj: PLoS ONE, Vol 7, Iss 1, p e29832 (2012)
Druh dokumentu: article
ISSN: 1932-6203
DOI: 10.1371/journal.pone.0029832
Popis: BackgroundPolyglutamine expansion is responsible for several neurodegenerative disorders, among which Huntington disease is the most well-known. Studies in the yeast model demonstrated that both aggregation and toxicity of a huntingtin (htt) protein with an expanded polyglutamine region strictly depend on the presence of the prion form of Rnq1 protein ([PIN+]), which has a glutamine/asparagine-rich domain.Principal findingsHere, we showed that aggregation and toxicity of mutant htt depended on [PIN+] only quantitatively: the presence of [PIN+] elevated the toxicity and the levels of htt detergent-insoluble polymers. In cells lacking [PIN+], toxicity of mutant htt was due to the polymerization and inactivation of the essential glutamine/asparagine-rich Sup35 protein and related inactivation of another essential protein, Sup45, most probably via its sequestration into Sup35 aggregates. However, inhibition of growth of [PIN+] cells depended on Sup35/Sup45 depletion only partially, suggesting that there are other sources of mutant htt toxicity in yeast.ConclusionsThe obtained data suggest that induced polymerization of essential glutamine/asparagine-rich proteins and related sequestration of other proteins which interact with these polymers represent an essential source of htt toxicity.
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