Therapeutic genetic variation revealed in diverse Hsp104 homologs

• DOI: 10.7554/elife.57457
• Publication Date: 2020-12-15T13:35:06Z
• Authors: Zachary M March; Katelyn Sweeney; Hanna Kim; Xiaohui Yan; Laura M Castellano; Meredith E Jackrel; JiaBei Lin; Edward Chuang; Edward Gomes; Corey W Willicott; Karolina Michalska; Robert P Jedrzejczak; Andrzej Joachimiak; Kim A Caldwell; Guy A Caldwell; Ophir Shalem; James Shorter
• Keywords: Protein Folding; Saccharomyces cerevisiae Proteins; TDP-43; QH301-705.5; Hsp104; alpha-synuclein; Science; Saccharomyces cerevisiae; Protein Aggregation, Pathological; Cell Line; 03 medical and health sciences; Biochemistry and Chemical Biology; Escherichia coli; chaperone; Animals; Humans; protein misfolding; Biology (General); Proteostasis Deficiencies; Caenorhabditis elegans; Heat-Shock Proteins; 0303 health sciences; Q; R; disaggregase; Genetic Variation; Neurodegenerative Diseases; Endopeptidase Clp; DNA-Binding Proteins; HEK293 Cells; alpha-Synuclein; Medicine; RNA-Binding Protein FUS

The AAA+ protein disaggregase, Hsp104, increases fitness under stress by reversing stress-induced protein aggregation. Natural Hsp104 variants might exist with enhanced, selective activity against neurodegenerative disease substrates. However, natural Hsp104 variation remains largely unexplored. Here, we screened a cross-kingdom collection of Hsp104 homologs in yeast proteotoxicity models. Prokaryotic ClpG reduced TDP-43, FUS, and α-synuclein toxicity, whereas prokaryotic ClpB and hyperactive variants were ineffective. We uncovered therapeutic genetic variation among eukaryotic Hsp104 homologs that specifically antagonized TDP-43 condensation and toxicity in yeast and TDP-43 aggregation in human cells. We also uncovered distinct eukaryotic Hsp104 homologs that selectively antagonized α-synuclein condensation and toxicity in yeast and dopaminergic neurodegeneration inC. elegans. Surprisingly, this therapeutic variation did not manifest as enhanced disaggregase activity, but rather as increased passive inhibition of aggregation of specific substrates. By exploring natural tuning of this passive Hsp104 activity, we elucidated enhanced, substrate-specific agents that counter proteotoxicity underlying neurodegeneration.