5 research outputs found
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Mining Disaggregase Sequence Space to Safely Counter TDP-43, FUS, and α-Synuclein Proteotoxicity.
Hsp104 is an AAA+ protein disaggregase, which can be potentiated via diverse mutations in its autoregulatory middle domain (MD) to mitigate toxic misfolding of TDP-43, FUS, and α-synuclein implicated in fatal neurodegenerative disorders. Problematically, potentiated MD variants can exhibit off-target toxicity. Here, we mine disaggregase sequence space to safely enhance Hsp104 activity via single mutations in nucleotide-binding domain 1 (NBD1) or NBD2. Like MD variants, NBD variants counter TDP-43, FUS, and α-synuclein toxicity and exhibit elevated ATPase and disaggregase activity. Unlike MD variants, non-toxic NBD1 and NBD2 variants emerge that rescue TDP-43, FUS, and α-synuclein toxicity. Potentiating substitutions alter NBD1 residues that contact ATP, ATP-binding residues, or the MD. Mutating the NBD2 protomer interface can also safely ameliorate Hsp104. Thus, we disambiguate allosteric regulation of Hsp104 by several tunable structural contacts, which can be engineered to spawn enhanced therapeutic disaggregases with minimal off-target toxicity
Disparate Mutations Confer Therapeutic Gain of Hsp104 Function
Hsp104,
a protein disaggregase from yeast, can be engineered and
potentiated to counter TDP-43, FUS, or α-synuclein misfolding
and toxicity implicated in neurodegenerative disease. Here, we reveal
that extraordinarily disparate mutations potentiate Hsp104. Remarkably,
diverse single missense mutations at 20 different positions interspersed
throughout the middle domain (MD) and small domain of nucleotide-binding
domain 1 (NBD1) confer a therapeutic gain of Hsp104 function. Moreover,
potentiation emerges from deletion of MD helix 3 or 4 or via synergistic
missense mutations in the MD distal loop and helix 4. We define the
most critical aspect of Hsp104 potentiation as enhanced disaggregase
activity in the absence of Hsp70 and Hsp40. We suggest that potentiation
likely stems from a loss of a fragilely constrained autoinhibited
state that enables precise spatiotemporal regulation of disaggregase
activity
Recommended from our members
Mining Disaggregase Sequence Space to Safely Counter TDP-43, FUS, and α-Synuclein Proteotoxicity.
Hsp104 is an AAA+ protein disaggregase, which can be potentiated via diverse mutations in its autoregulatory middle domain (MD) to mitigate toxic misfolding of TDP-43, FUS, and α-synuclein implicated in fatal neurodegenerative disorders. Problematically, potentiated MD variants can exhibit off-target toxicity. Here, we mine disaggregase sequence space to safely enhance Hsp104 activity via single mutations in nucleotide-binding domain 1 (NBD1) or NBD2. Like MD variants, NBD variants counter TDP-43, FUS, and α-synuclein toxicity and exhibit elevated ATPase and disaggregase activity. Unlike MD variants, non-toxic NBD1 and NBD2 variants emerge that rescue TDP-43, FUS, and α-synuclein toxicity. Potentiating substitutions alter NBD1 residues that contact ATP, ATP-binding residues, or the MD. Mutating the NBD2 protomer interface can also safely ameliorate Hsp104. Thus, we disambiguate allosteric regulation of Hsp104 by several tunable structural contacts, which can be engineered to spawn enhanced therapeutic disaggregases with minimal off-target toxicity