TY - JOUR
T1 - A Caenorhabditis elegans Parkin mutant with altered solubility couples α-synuclein aggregation to proteotoxic stress
AU - Springer, Wolfdieter
AU - Hoppe, Thorsten
AU - Schmidt, Enrico
AU - Baumeister, Ralf
N1 - Funding Information:
We thank Bianca Sperl for excellent technical assistance, Philipp Kahle, Stefan Eimer and the members of the Baumeister lab for helpful discussions and critical reading of the manuscript, Christian Haass for support, Claudia Rudolph (EleGene) for isolating pdr-1(lg103) and pdr-1(lg101), Julia Sämann for help with the yeast experiments, Shohei Mitani for providing pdr-1(tm598) and pdr-1(tm395), Garry Wong for integrated α-synuclein strains, Randal Kauf-mann, David Ron, Randy Blakely, Andy Fire, Martin Scheff-ner and Robert Barstead for strains, plasmids and cDNA libraries. Some strains used in this study were obtained from the C. elegans Genetics Center, St Louis, which is funded by the NIH. This work was supported by grants from the European Community (through the Integrated Project APOPIS), the Friedrich-Baur Stiftung, the Fonds der Chemischen Industrie to R.B., and the Deutsche Forschungs-gemeinschaft to R.B. (SFB596) and to T.H. (SFB 444).
PY - 2005/11/15
Y1 - 2005/11/15
N2 - Mutations in the human parkin gene encoding an E3 ubiquitin ligase have been associated with early-onset recessive forms of Parkinson's disease (PD). However, the molecular mechanisms by which mutations in the parkin gene cause PD are still under debate. Here, we identified and characterized the Caenorhabditis elegans parkin homolog, pdr-1. PDR-1 protein physically associates and cooperates with a conserved degradation machinery to mediate ubiquitin conjugation. Strikingly, in contrast to pdr-1 loss-of-function mutants, an in-frame deletion variant with altered solubility and intracellular localization properties is hypersensitive toward different proteotoxic stress conditions. Both endoplasmic reticulum-derived folding stress and cytosolic stress conferred by expression of mutant human α-synuclein resulted in severe developmental defects and lethality in pdr-1(lg103) mutant background. Furthermore, we show that the corresponding truncated protein PDR-1(Δaa24-247) aggregates in cell culture, but still interacts with its ubiquitylation co-enzymes. Thus, it might block the cellular degradation/detoxification machinery and therefore renders worms highly vulnerable to protein folding stress. In contrast to other complete gene knockouts or RNAi models of Parkin function, this C. elegans model recapitulates Parkin insolubility and aggregation similar to several autosomal recessive juvenile parkinsonism (AR-JP)-linked Parkin mutations. We suggest that such Parkin variants that either confer a neomorphic function or a partial loss-of-function may help to further elucidate the biological function of Parkin in vivo and the pathogenic mechanisms resulting in AR-JP. Due to high-throughput capacity of C. elegans, this model is particularly well suited to identify genetic and chemical modifiers of toxicity.
AB - Mutations in the human parkin gene encoding an E3 ubiquitin ligase have been associated with early-onset recessive forms of Parkinson's disease (PD). However, the molecular mechanisms by which mutations in the parkin gene cause PD are still under debate. Here, we identified and characterized the Caenorhabditis elegans parkin homolog, pdr-1. PDR-1 protein physically associates and cooperates with a conserved degradation machinery to mediate ubiquitin conjugation. Strikingly, in contrast to pdr-1 loss-of-function mutants, an in-frame deletion variant with altered solubility and intracellular localization properties is hypersensitive toward different proteotoxic stress conditions. Both endoplasmic reticulum-derived folding stress and cytosolic stress conferred by expression of mutant human α-synuclein resulted in severe developmental defects and lethality in pdr-1(lg103) mutant background. Furthermore, we show that the corresponding truncated protein PDR-1(Δaa24-247) aggregates in cell culture, but still interacts with its ubiquitylation co-enzymes. Thus, it might block the cellular degradation/detoxification machinery and therefore renders worms highly vulnerable to protein folding stress. In contrast to other complete gene knockouts or RNAi models of Parkin function, this C. elegans model recapitulates Parkin insolubility and aggregation similar to several autosomal recessive juvenile parkinsonism (AR-JP)-linked Parkin mutations. We suggest that such Parkin variants that either confer a neomorphic function or a partial loss-of-function may help to further elucidate the biological function of Parkin in vivo and the pathogenic mechanisms resulting in AR-JP. Due to high-throughput capacity of C. elegans, this model is particularly well suited to identify genetic and chemical modifiers of toxicity.
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U2 - 10.1093/hmg/ddi371
DO - 10.1093/hmg/ddi371
M3 - Article
C2 - 16204351
AN - SCOPUS:27944506923
SN - 0964-6906
VL - 14
SP - 3407
EP - 3423
JO - Human molecular genetics
JF - Human molecular genetics
IS - 22
ER -