Enhancement of the Anti-Aggregation Activity of a Molecular Chaperone Using a Rationally Designed Post-Translational Modification

Abstract

Protein behavior is closely regulated by a plethora of post-translational modifications (PTMs). It is therefore desirable to develop approaches to design rational PTMs to modulate specific protein functions. Here, we report one such method, and we illustrate its successful implementation by potentiating the anti-aggregation activity of a molecular chaperone. Molecular chaperones are a multifaceted class of proteins essential to protein homeostasis, and one of their major functions is to combat protein misfolding and aggregation, a phenomenon linked to a number of human disorders. In this work, we conjugated a small-molecule inhibitor of the aggregation of α-synuclein, a process associated with Parkinson’s disease (PD), to a specific cysteine residue on human Hsp70, a molecular chaperone with five free cysteines. We show that this regioselective conjugation augments in vitro the anti-aggregation activity of Hsp70 in a synergistic manner. This Hsp70 variant also displays in vivo an enhanced suppression of α-synuclein aggregation and its associated toxicity in a Caenorhabditis elegans model of PD.

Augmentation of Bri2 molecular chaperone activity against amyloid-β reduces neurotoxicity in mouse hippocampus in vitro

“…The chaperone activity of alkyl hydroperoxide reductase C from Pseudomonas aeruginosa was enhanced by a point-specific mutation that results in the formation of large oligomers, and the mutant confers heat tolerance to E. coli 72 . Recently, conjugation of a small-molecule inhibitor of α-synuclein aggregation to Hsp70 was shown to augment the anti-aggregation activity 8 . In our current study, augmentation of rh Bri2 BRICHOS activity against Aβ42-induced neurotoxicity is shown to occur as a result of formation of monomeric species from larger oligomers (Fig.…”

“…The results hence suggest a rational concept to enhance endogenous Bri2 BRICHOS activity against Aβ42-induced neurotoxicity. Rational reprogramming of endogenous chaperone activity may find broad applicability in the fight against proteinmisfolding diseases 1,[5][6][7][8] . BRICHOS is a recently established molecular chaperone domain, which efficiently prevents fibrillar amyloid aggregation as well as its associated toxicity, as shown in vitro, in mouse hippocampal slice preparations, and in Drosophila models 19,23,26,27,32,34,35 .…”

“…Surveillance by human molecular chaperones may decline during aging, resulting in increased cellular stress and eventually leading to neurodegenerative diseases and other disorders [2][3][4] . Thus, pharmacologically augmenting or stimulating chaperone capacity could have therapeutic potential [4][5][6] , and strategies to increase the specificity and activity of the interactions of molecular chaperones with their target substrates are sought for 7,8 .…”

Do Post-Translational Modifications Influence Protein Aggregation in Neurodegenerative Diseases: A Systematic Review

“…Against this backdrop, the identification of the PTMs that drive dysregulated protein function proffer a therapeutic window if the formation of toxic protein aggregates could be obviated. Indeed, recent animal studies have demonstrated that therapies that influence protein PTMs provide a viable means to modulate proteinopathy and associated neurodegeneration [91,92].…”

Hsp60 Post-translational Modifications: Functional and Pathological Consequences

“…Proteins with PTM are involved in all fundamental cellular processes. For example, lysine modification of nuclear proteins play a crucial role in gene regulation (McIntyre and Woodgate, 2015), and modified proteins are critical to maintain protein homeostasis (Minguez et al, 2012;Lindstedt et al, 2019). Likewise, phosphorylation, S-nitrosylation, and acetylation of mitochondrial proteins occur to modulate their functions inside the organelle (Foster et al, 2009;Mailloux et al, 2014).…”