Structure of Calcarisporiella thermophila Hsp104 Disaggregase that Antagonizes Diverse Proteotoxic Misfolding Events

• Published in: Structure (London) Vol. 27; no. 3; pp. 449 - 463.e7
• Main Authors: Michalska, Karolina, Zhang, Kaiming, March, Zachary M., Hatzos-Skintges, Catherine, Pintilie, Grigore, Bigelow, Lance, Castellano, Laura M., Miles, Leann J., Jackrel, Meredith E., Chuang, Edward, Jedrzejczak, Robert, Shorter, James, Chiu, Wah, Joachimiak, Andrzej
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 05.03.2019; Elsevier
• Subjects: Adenosine Triphosphatases - chemistry; Adenosine Triphosphatases - pharmacology; alpha-Synuclein - antagonists & inhibitors; BASIC BIOLOGICAL SCIENCES; Cryoelectron Microscopy; Crystallography, X-Ray; DNA-Binding Proteins - antagonists & inhibitors; Fungal Proteins - chemistry; Fungal Proteins - pharmacology; Humans; Models, Molecular; Mucorales - enzymology; Peptides - antagonists & inhibitors; Protein Conformation, alpha-Helical; Proteostasis Deficiencies - prevention & control
• ISSN: 0969-2126; 1878-4186
• DOI: 10.1016/j.str.2018.11.001

Hsp104 is an AAA+ protein disaggregase with powerful amyloid-remodeling activity. All nonmetazoan eukaryotes express Hsp104 while eubacteria express an Hsp104 ortholog, ClpB. However, most studies have focused on Hsp104 from Saccharomyces cerevisiae and ClpB orthologs from two eubacterial species. Thus, the natural spectrum of Hsp104/ClpB molecular architectures and protein-remodeling activities remains largely unexplored. Here, we report two structures of Hsp104 from the thermophilic fungus Calcarisporiella thermophila (CtHsp104), a 2.70Å crystal structure and 4.0Å cryo-electron microscopy structure. Both structures reveal left-handed, helical assemblies with all domains clearly resolved. We thus provide the highest resolution and most complete view of Hsp104 hexamers to date. We also establish that CtHsp104 antagonizes several toxic protein-misfolding events in vivo where S. cerevisiae Hsp104 is ineffective, including rescue of TDP-43, polyglutamine, and α-synuclein toxicity. We suggest that natural Hsp104 variation is an invaluable, untapped resource for illuminating therapeutic disaggregases for fatal neurodegenerative diseases. •The dynamic assembly shows varying tunnel width, helical rise, and domain orientation•The N-terminal domain and C-terminal tail are not required for CtHsp104 hexamerization•CtHsp104 rescues TDP-43, polyGlu and α-Syn toxicity in yeast and is well tolerated•CtHsp104 confers thermotolerance to yeast suggesting collaboration with Hsp70/Hsp40 X-ray crystal and cryo-EM structures of Hsp104 from thermophilic fungus were determined by Michalska et al. Structures reveal left-handed, helical, dynamic assemblies with all domains resolved. This disaggregase robustly antagonizes toxic protein-misfolding events in vivo where yeast Hsp104 is ineffective. Natural Hsp104 variants can provide an untapped therapeutic resource for neurodegenerative diseases.