Example 157
α-synuclein and ApoE4 yeast strains were previously engineered to express the human α-synuclein or ApoE4 genes under control of the yeast galactose-regulated promoter, GAL1 , as described in International Patent Publication No. W02016/040794 and U.S. Pat. Nos. 7,452,670 and 7,045,290, the procedures for the production of such strains of which are herein incorporated by reference. The induced expression of α-synuclein and ApoE4 confers cytotoxicity, thus enabling the identification of compounds that can restore cell viability. This instantaneous/synchronous induction of α-synuclein and ApoE4 can be achieved due to the following expression control. In glucose-containing media, gene expression from the GAL1 promoter is ‘off’ and actively repressed by additional epigenetic factors. In raffinose, expression is ‘off’, but the promoter not actively repressed. Upon transition to galactose-containing media, the promoter is instantaneously turned ‘on’ to achieve robust and synchronous induction of α-synuclein or ApoE4 expression. This highly regulated induction provides a robust window for the determination of both efficacy (amplitude of protective effect) and potency (concentration of protective effect) of cytoprotective compounds.
