Hsp70 chaperones accelerate protein translocation and the unfolding of stable protein aggregates by entropic pulling.

Details

Serval ID
serval:BIB_B3B67018F7A6
Type
Article: article from journal or magazin.
Collection
Publications
Title
Hsp70 chaperones accelerate protein translocation and the unfolding of stable protein aggregates by entropic pulling.
Journal
Proceedings of the National Academy of Sciences of the United States of America
Author(s)
De Los Rios P., Ben-Zvi A., Slutsky O., Azem A., Goloubinoff P.
ISSN
0027-8424 (Print)
ISSN-L
0027-8424
Publication state
Published
Issued date
2006
Volume
103
Number
16
Pages
6166-6171
Language
english
Abstract
Hsp70s are highly conserved ATPase molecular chaperones mediating the correct folding of de novo synthesized proteins, the translocation of proteins across membranes, the disassembly of some native protein oligomers, and the active unfolding and disassembly of stress-induced protein aggregates. Here, we bring thermodynamic arguments and biochemical evidences for a unifying mechanism named entropic pulling, based on entropy loss due to excluded-volume effects, by which Hsp70 molecules can convert the energy of ATP hydrolysis into a force capable of accelerating the local unfolding of various protein substrates and, thus, perform disparate cellular functions. By means of entropic pulling, individual Hsp70 molecules can accelerate unfolding and pulling of translocating polypeptides into mitochondria in the absence of a molecular fulcrum, thus settling former contradictions between the power-stroke and the Brownian ratchet models for Hsp70-mediated protein translocation across membranes. Moreover, in a very different context devoid of membrane and components of the import pore, the same physical principles apply to the forceful unfolding, solubilization, and assisted native refolding of stable protein aggregates by individual Hsp70 molecules, thus providing a mechanism for Hsp70-mediated protein disaggregation.
Keywords
Bacterial Proteins/chemistry, Bacterial Proteins/metabolism, Entropy, HSP70 Heat-Shock Proteins/chemistry, HSP70 Heat-Shock Proteins/metabolism, Mitochondria/metabolism, Mitochondrial Proteins/chemistry, Mitochondrial Proteins/metabolism, Models, Molecular, Molecular Chaperones/chemistry, Molecular Chaperones/metabolism, Protein Folding, Protein Transport
Pubmed
Web of science
Open Access
Yes
Create date
24/01/2008 21:02
Last modification date
20/08/2019 16:22
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