The accumulation and prion-like propagation of α-synuclein and other amyloidogenic proteins are associated with devastating neurodegenerative diseases. Metazoan heat shock protein HSP70 and its co-chaperones DNAJB1 and HSP110 constitute a disaggregation machinery that is able to disassemble α-synuclein fibrils in vitro, but its physiological effects on α-synuclein toxicity are unknown. Here, we depleted Caenorhabditis elegans HSP-110 and monitored the consequences on α-synuclein-related pathological phenotypes such as misfolding, intercellular spreading, and toxicity in C. elegans in vivo models. Depletion of HSP-110 impaired HSP70 disaggregation activity, prevented resolubilization of amorphous aggregates, and compromised the overall cellular folding capacity. At the same time, HSP-110 depletion reduced α-synuclein foci formation, cell-to-cell transmission, and toxicity. These data demonstrate that the HSP70 disaggregation activity constitutes a double-edged sword, as it is essential for maintaining cellular proteostasis but also involved in the generation of toxic amyloid-type protein species.
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http://dx.doi.org/10.15252/embj.2019103954 | DOI Listing |
Molecules
December 2024
Institute of Chemistry, University of Campinas UNICAMP, Campinas 13083-862, SP, Brazil.
HSP70 chaperones play pivotal roles in facilitating protein folding, refolding, and disaggregation through their binding and releasing activities. This intricate process is further supported by J-domain proteins (JDPs), also known as DNAJs or HSP40s, which can be categorized into classes A and B. In yeast, these classes are represented by Ydj1 and Sis1, respectively.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2024
Laboratory for Protein Conformation Diseases, RIKEN Center for Brain Science, Wako, Saitama 351-0198, Japan.
The dynamic balance between formation and disaggregation of amyloid fibrils is associated with many neurodegenerative diseases. Multiple chaperones interact with and disaggregate amyloid fibrils, which impacts amyloid propagation and cellular phenotypes. However, it remains poorly understood whether and how site-specific binding of chaperones to amyloids facilitates the concerted disaggregation process and modulates physiological consequences in vivo.
View Article and Find Full Text PDFElife
October 2024
Intercollegiate Faculty of Biotechnology of University of Gdańsk and Medical University of Gdańsk, University of Gdańsk, Gdańsk, Poland.
Hsp70 is a key cellular system counteracting protein misfolding and aggregation, associated with stress, ageing, and disease. Hsp70 solubilises aggregates and aids protein refolding through substrate binding and release cycles regulated by co-chaperones: J-domain proteins (JDPs) and nucleotide exchange factors (NEFs). Here, we elucidate the collaborative impact of Hsp110 NEFs and different JDP classes throughout Hsp70-dependent aggregate processing.
View Article and Find Full Text PDFNat Commun
October 2024
Department of Inorganic and Analytical Chemistry, Chemistry and Biochemistry, University of Geneva, Geneva, 1211, Switzerland.
PLoS Genet
October 2024
Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, United States of America.
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