Drivers of Hsp104 potentiation revealed by scanning mutagenesis of the middle domain

Abstract

Hsp104, a yeast protein disaggregase, can be potentiated via numerous missense mutations at disparate locations throughout the coiled-coil middle domain (MD). Potentiated Hsp104 variants can counter the toxicity and misfolding of TDP-43, FUS, and α-synuclein, proteins which are implicated in

Molecular determinants and modifiers of Matrin-3 toxicity, condensate dynamics, and droplet morphology

“…Hsp104 has been shown to have limited activity in solubilizing amyloid and amyloid-like substrates associated with human disease, including TDP-43, FUS, and α-synuclein ( DeSantis et al., 2012 ; Jackrel et al., 2014 ; Jackrel and Shorter, 2014a , 2014b , 2015 ; Lo Bianco et al., 2008 ). However, we have demonstrated that Hsp104 can be re-engineered to yield potentiated variants that display robust remodeling activity against a range of substrates including TDP-43, FUS, α-synuclein and TAF15 ( Castellano et al., 2015 ; DeSantis et al., 2012 ; Jackrel et al., 2014 ; Jackrel and Shorter, 2014a , 2014b , 2015 , 2017 ; Michalska et al., 2019 ; Ryan et al., 2019 , 2021 ; Sweeny et al., 2015 ; Tariq et al., 2018 , 2019 ; Yasuda et al., 2017 ). We therefore hypothesized that these same potentiated Hsp104 variants may also be capable of remodeling MATR3.…”

Design principles to tailor Hsp104 therapeutics

“…We designed 46 mutations aiming to alter these interactions, of which 16 have been tested previously. 29,30,39,58,59,63 Thus, we generated 30 additional single missense Hsp104 variants expected to alter the interactions of this interface (Table S2 and Figure 1B).…”

“…13 Indeed, single mutations in the MD can relieve autoinhibition and enhance Hsp104 disaggregase activity. [36][37][38][39][40][41] Precisely how the MD permits or restricts Hsp104 disaggregase activity is not completely understood. Hsp70 and Hsp40 enable optimal Hsp104 disaggregase activity.…”

Prion-Like Proteins in Phase Separation and Their Link to Disease

“…Although metazoans lack an Hsp104 homolog, it was hypothesized that Hsp104 might be active against proteins that aggregate in human disease due to the conserved fold of amyloid and prion-like proteins. While activity of Hsp104 against many human disease-associated proteins is weak, potentiated variants of Hsp104 have been engineered that can prevent and reverse the misfolding of diverse proteins including TDP-43, FUS, and α-Syn [198][199][200][201][202][203][204][205][206][207][208][209][210][211]. Potentiated Hsp104 variants also displayed therapeutic activity in worm and mammalian cell models of neurodegenerative disease [198,212,213].…”