Yeast Genes That Enhance the Toxicity of a Mutant Huntingtin Fragment or α-Synuclein

Willingham, Stephen B.; Outeiro, Tiago F.; DeVit, Michael J.; Lindquist, Susan; Muchowski, Paul J.

doi:10.1126/science.1090389

Cited by 393 publications

(339 citation statements)

References 30 publications

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“…In conclusion, we support a model of yeast toxicity in which overexpressed monomeric synuclein directly coats the plasma and internal membranes via its amphipathic α-helices, disrupting normal membrane processes (including vesicle trafficking [19][20][21], and eventually leading to toxicity. Perhaps the simplest mechanism by which synuclein binding could disrupt membrane processes is a non-specific one.…”

Section: Is Membrane Binding Necessary For Synuclein Induced Yeast Tosupporting

confidence: 73%

“…We are using the yeast Saccharomyces cerevisiae as an in vivo model system, which exhibits toxicity (defined here as slowed growth) and α-synuclein inclusion formation. 18,19 Wild type and A53T α-synuclein are both toxic and localize to inclusions and the plasma membrane when expressed from multiple GAL promoters, such as those on 2-micron plasmids (high copy number) or from multiple integrated copies. 18,20,21 In contrast, the A30P variant is non-toxic to yeast and is uniformly distributed throughout the cytoplasm.…”

Section: Introductionmentioning

confidence: 99%

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Relationships between the Sequence of α-Synuclein and its Membrane Affinity, Fibrillization Propensity, and Yeast Toxicity

Volles

Lansbury

2007

Journal of Molecular Biology

223

206

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SummaryTo investigate the α-synuclein protein and its role in Parkinson's disease, we screened a library of random point mutants both in vitro and in yeast to find variants in an unbiased way that could help us understand the sequence-phenotype relationship. We developed a rapid purification method that allowed us to screen 59 synuclein mutants in vitro and discovered two double point mutants that fibrillized slowly relative to wild type, A30P, and A53T α-synucleins. The yeast toxicity of all of these proteins was measured and we found no correlation with fibrillization rate, suggesting that fibrillization is not necessary for synuclein-induced yeast toxicity. We also found that β-synuclein was of intermediate toxicity to yeast and γ-synuclein was non-toxic. Coexpression of Parkinson's disease related genes DJ-1, parkin, Pink1, UCH-L1, or synphilin, with synuclein, did not affect synuclein toxicity. A second screen, of several thousand library clones in yeast, identified 25 nontoxic α-synuclein sequence variants. Most of these contained a mutation to either proline or glutamic acid that caused a defect in membrane binding. We hypothesize that yeast toxicity is caused by synuclein binding directly to membranes at levels sufficient to non-specifically disrupt homeostasis.

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Section: Is Membrane Binding Necessary For Synuclein Induced Yeast Tosupporting

confidence: 73%

Section: Introductionmentioning

confidence: 99%

Relationships between the Sequence of α-Synuclein and its Membrane Affinity, Fibrillization Propensity, and Yeast Toxicity

Volles

Lansbury

2007

Journal of Molecular Biology

223

206

View full text Add to dashboard Cite

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“…A screen of the complete set of viable gene deletion strains from yeast that are more sensitive to the heterologous expression of a-synuclein has identified 86 different genes including YGL231c [25]. We found that there was a noticeable decrease in the viability of YGL231cD cells expressing a-synuclein when compared to wild type cells (40.1 ± 2.2% vs. 47.4 ± 1.8%).…”

Section: Yeast Tmem85 Protects Against H 2 O 2 Induced Stressmentioning

confidence: 88%

Transmembrane protein 85 from both human (TMEM85) and yeast (YGL231c) inhibit hydrogen peroxide mediated cell death in yeast

et al. 2008

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Anti-apoptotic proteins are involved in modulating the process of apoptosis. Here, we report the identification of the previously uncharacterized transmembrane domain protein 85 (TMEM85) as a novel anti-apoptotic sequence. Using growth and viability assays, we demonstrate that the heterologous expression of human TMEM85 in yeast promotes growth and prevents cell death in response to oxidative stress. Overexpression of the yeast TMEM85 ortholog (YGL231c) also leads to increased resistance to oxidative stress. Analysis of the existing TMEM85 DNA complimentary to mRNAs revealed that the human TMEM85 gene is alternatively spliced to produce multiple transcripts and proteins. Thus TMEM85 is a complex gene that encodes a novel conserved anti-apoptotic protein.

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“…Combinations of these factors must account for their different pathobiologies. Recent studies have started to identify protein-protein and genetic interaction networks for polyQ proteins (6)(7)(8), but the current data do not yet provide a framework for understanding the distinct molecular pathologies caused by different polyQ expansion proteins.…”

mentioning

confidence: 99%

A network of protein interactions determines polyglutamine toxicity

Duennwald

Jagadish

Giorgini

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

144

193

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Several neurodegenerative diseases are associated with the toxicity of misfolded proteins. This toxicity must arise from a combination of the amino acid sequences of the misfolded proteins and their interactions with other factors in their environment. A particularly compelling example of how profoundly these intramolecular and intermolecular factors can modulate the toxicity of a misfolded protein is provided by the polyglutamine (polyQ) diseases. All of these disorders are caused by glutamine expansions in proteins that are broadly expressed, yet the nature of the proteins that harbor the glutamine expansions and the particular pathologies they produce are very different. We find, using a yeast model, that amino acid sequences that modulate polyQ toxicity in cis can also do so in trans. Furthermore, the prion conformation of the yeast protein Rnq1 and the level of expression of a suite of other glutamine-rich proteins profoundly affect polyQ toxicity. They can convert polyQ expansion proteins from toxic to benign and vice versa. Our work presents a paradigm for how a complex, dynamic interplay between intramolecular features of polyQ proteins and intermolecular factors in the cellular environment might determine the unique pathobiologies of polyQ expansion proteins.huntingtin ͉ Huntington's disease ͉ protein misfolding ͉ yeast A variety of human diseases are characterized by the accumulation of aggregated, misfolded proteins (1, 2). In some cases, such as cystic fibrosis, disease is caused by the loss of a vital protein function due simply to this misfolding and aggregation. In other cases, however, protein misfolding creates novel, toxic properties. For example, in Alzheimer's disease, Parkinson's disease, and the polyglutamine (polyQ) disorders, misfolded proteins disrupt proper cellular function and cause cytotoxicity (3,4). In all of these diseases the amino acid sequences of the particular misfolded protein and their interactions determined by its specific environment must govern toxicity. Yet, despite intense research, we know little about these intramolecular and intermolecular factors. Without identifying and understanding these factors at a molecular level it will be difficult to devise the most effective therapeutic strategies to treat protein misfolding diseases.The polyQ diseases present a promising starting point to study this very general problem. In all of these diseases polyQ expansions constitute the molecular basis of disease (5). However, the disease pathologies (including the cell types most strongly affected) and the individual proteins that bear the disease-causing polyQ expansions are very distinct (5). Consequently, the amino acids flanking the polyQ region and the sets of cellular factors that specifically interact with each polyQ expansion protein are different. Combinations of these factors must account for their different pathobiologies. Recent studies have started to identify protein-protein and genetic interaction networks for polyQ proteins (6-8), but the current data do not yet ...

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Yeast Genes That Enhance the Toxicity of a Mutant Huntingtin Fragment or α-Synuclein

Cited by 393 publications

References 30 publications

Relationships between the Sequence of α-Synuclein and its Membrane Affinity, Fibrillization Propensity, and Yeast Toxicity

Relationships between the Sequence of α-Synuclein and its Membrane Affinity, Fibrillization Propensity, and Yeast Toxicity

Transmembrane protein 85 from both human (TMEM85) and yeast (YGL231c) inhibit hydrogen peroxide mediated cell death in yeast

A network of protein interactions determines polyglutamine toxicity

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