A novel yeast‐based screening system for potential compounds that can alleviate human α‐synuclein toxicity

AIMS: This study aimed to establish a yeast‐based screening system for potential compounds that can alleviate the toxicity of α‐synuclein (α‐syn), a neuropathological hallmark of Parkinson’s disease, either inhibition of α‐syn aggregation or promotion of ubiquitin‐mediated degradation of α‐syn. METHODS AND RESULTS: A powerful yeast‐based screening assay using the rsp5 (A401E)‐mutant strain, which is hypersensitive to α‐syn aggregation, was established by two‐step gene replacement and further overexpressed the GFP‐fused α‐syn in the drug‐sensitive yeast strain with a galactose‐inducible multicopy plasmid. The rsp5 (A401E)‐mutant strain treated with baicalein, a known α‐syn aggregation inhibitor, showed better α‐syn toxicity alleviation than the same background wild type strain as accessed by comparison on the reduction kinetics of viable dye resazurin fluorometrically (λ(ex)540/λ(em)590 nm). The rsp5 (A401E)‐mutant yeast‐based assay system showed high sensitivity as it could detect as low as 3.13 µmol l(−1) baicalein, the concentration that lower than previously report detected by the in vitro assay. CONCLUSIONS: Our yeast‐based system has been effective for screening potential compounds that can alleviate α‐syn toxicity with high sensitivity and specificity. SIGNIFICANCE AND IMPACT OF THE STUDY: Yeast‐based assay system can be used to discover novel neuroprotective drug candidates which may be either efficiently suppress‐α‐syn aggregation or enhance ubiquitin‐dependent degradation.