The Impact of Hidden Structure on Aggregate Disassembly by Molecular Chaperones
Daniel Shoup1, Andrew Roth1, Jason Puchalla2
1Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, United States.
Frontiers in Molecular Biosciences
|July 25, 2022
Summary
Protein aggregation is a cellular danger. Molecular chaperones disaggregate protein clumps, but internal structure, not size, dictates disassembly speed, revealing new insights into cellular quality control.
Area of Science:
- Biochemistry
- Molecular Biology
- Cellular Biology
Background:
- Protein aggregation is a detrimental process linked to cellular dysfunction and disease.
- Molecular chaperones are essential for disassembling protein aggregates.
- The precise mechanisms of aggregate recognition and disassembly by chaperones are not fully understood.
Purpose of the Study:
- To investigate the mechanism of chaperone-mediated protein disaggregation.
- To determine the influence of aggregate particle size versus internal structure on disassembly.
- To model the process using the bi-chaperone disaggregase system from Escherichia coli.
Main Methods:
- Utilized Burst Analysis Spectroscopy (BAS), a single-particle fluorescence technique.
- Employed two structurally distinct aggregate types derived from the same protein.
- Analyzed the interaction between molecular chaperones and protein aggregates.
Main Results:
- Aggregate particle size has minimal impact on the rate of disassembly.
- Changes in internal protein aggregate structure, undetectable by size or chaperone binding, significantly impede disaggregation.
- These structure-induced resistance mechanisms develop rapidly, within minutes.
Conclusions:
- Internal protein aggregate structure, rather than size, is a critical determinant of chaperone-mediated disassembly.
- Rapid structural changes can render aggregates resistant to cellular quality control.
- This highlights the importance of aggregate substructure in cellular protein homeostasis.
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