Suppression of protein aggregation by chaperone modification of high molecular weight complexes

John Labbadia, Sergey S. Novoselov, John S. Bett, Andreas Weiss, Paolo Paganetti, Gillian P. Bates, Michael E. Cheetham

Research output: Contribution to journalArticlepeer-review

91 Citations (Scopus)

Abstract

Protein misfolding and aggregation are associated with many neurodegenerative diseases, including Huntington's disease. The cellular machinery for maintaining proteostasis includes molecular chaperones that facilitate protein folding and reduce proteotoxicity. Increasing the protein folding capacity of cells through manipulation of DNAJ chaperones has been shown to suppress aggregation and ameliorate polyglutamine toxicity in cells and flies. However, to date these promising findings have not been translated to mammalian models of disease. To address this issue, we developed transgenic mice that over-express the neuronal chaperone HSJ1a (DNAJB2a) and crossed them with the R6/2 mouse model of Huntington's disease. Over-expression of HSJ1a significantly reduced mutant huntingtin aggregation and enhanced solubility. Surprisingly, this was mediated through specific association with K63 ubiquitylated, detergent insoluble, higher order mutant huntingtin assemblies that decreased their ability to nucleate further aggregation. This was dependent on HSJ1a client binding ability, ubiquitin interaction and functional co-operation with HSP70. Importantly, these changes in mutant huntingtin solubility and aggregation led to improved neurological performance in R6/2 mice. These data reveal that prevention of further aggregation of detergent insoluble mutant huntingtin is an additional level of quality control for late stage chaperone-mediated neuroprotection. Furthermore, our findings represent an important proof of principle that DNAJ manipulation is a valid therapeutic approach for intervention in Huntington's disease.

Original languageEnglish
Pages (from-to)1180-1196
Number of pages17
JournalBrain
Volume135
Issue number4
Early online date6 Mar 2012
DOIs
Publication statusPublished - Apr 2012

Fingerprint

Dive into the research topics of 'Suppression of protein aggregation by chaperone modification of high molecular weight complexes'. Together they form a unique fingerprint.

Cite this