Human Molecular Chaperone Hsp60 and Its Apical Domain Suppress Amyloid Fibril Formation of α-Synuclein

Abstract

Heat shock proteins play roles in assisting other proteins to fold correctly and in preventing the aggregation and accumulation of proteins in misfolded conformations. However, the process of aging significantly degrades this ability to maintain protein homeostasis. Consequently, proteins with incorrect conformations are prone to aggregate and accumulate in cells, and this aberrant aggregation of misfolded proteins may trigger various neurodegenerative diseases, such as Parkinson’s disease. Here, we investigated the possibilities of suppressing α-synuclein aggregation by using a mutant form of human chaperonin Hsp60, and a derivative of the isolated apical domain of Hsp60 (Hsp60 AD(Cys)). In vitro measurements were used to detect the effects of chaperonin on amyloid fibril formation, and interactions between Hsp60 proteins and α-synuclein were probed by quartz crystal microbalance analysis. The ability of Hsp60 AD(Cys) to suppress α-synuclein intracellular aggregation and cytotoxicity was also demonstrated. We show that Hsp60 mutant and Hsp60 AD(Cys) both effectively suppress α-synuclein amyloid fibril formation, and also demonstrate for the first time the ability of Hsp60 AD(Cys) to function as a mini-chaperone inside cells. These results highlight the possibility of using Hsp60 AD as a method of prevention and treatment of neurodegenerative diseases.

Spearmint Extract Containing Rosmarinic Acid Suppresses Amyloid Fibril Formation of Proteins Associated with Dementia

“…The cell viability measurements were performed according to previous studies on the mouse neuroblastoma cell line Neuro2a (N2a), using a Tali™ Image-Based Cytometer (Thermo Fisher Scientific, Waltham, MA, USA) [ 28 ]. N2a cells were obtained from Public Health England.…”

HSP90 Co-Chaperone, CacyBP/SIP, Protects α-Synuclein from Aggregation

“…For instance, it has been shown that, in vitro, HSP70 alone or in cooperation with different chaperones/co-chaperones inhibits formation of α-synuclein fibrils [ 35 , 36 ] and tau aggregates [ 32 ], and reduces polyglutamine (polyQ)-induced toxicity when exogenously added to cultured cells [ 37 ]. Other chaperones such as HSP60 and HSP40 have been shown to suppress α-synuclein fibrillization in vitro and to block the polyQ-induced toxicity, respectively [ 38 , 39 ]. In turn, overexpression of αB-crystallin and HSP27, members of small heat shock protein family (sHSP), significantly reduces the intracellular aggregation of α-synuclein and inhibits cytotoxicity of α-synuclein fibrils [ 40 ].…”

An α-synuclein decoy peptide prevents cytotoxic α-synuclein aggregation caused by fatty acid binding protein 3

“…pCAG-GFP and mCherry2-N1 genes were a gift from Connie Cepko (Addgene plasmid # 11150; http://n2t.net/addgene:11150 ; RRID:Addgene_11150) and from Michael Davidson (Addgene plasmid # 54517; http://n2t.net/addgene:54517 ; RRID:Addgene_54517), respectively. The plasmid pCAG-GFP-αSyn was previously constructed in our laboratory ( 59 ). pCAG-FABP3-mCherry was prepared by substituting the GFP ORF of pCAG-GFP with a synthetic FABP3-mCherry gene (Integrated DNA Technologies).…”