scholarly journals Cochaperones enable Hsp70 to fold proteins like a Maxwell’s demon

2018 ◽  
Author(s):  
Huafeng Xu
Keyword(s):  
Free Energy ◽  
Protein Folding ◽  
Heat Shock ◽  
Heat Shock Protein 70 ◽  
Protein Quality ◽  
Atp Hydrolysis ◽  
Cellular Protein ◽  
Native State ◽  
Refolding Kinetics ◽  
Stimulation Of

AbstractThe heat shock protein 70 (Hsp70) chaperones, vital to the proper folding of proteins inside cells, consume ATP and require cochaperones in assisting protein folding. It is unclear whether Hsp70 can utilize the free energy from ATP hydrolysis to fold a protein into a native state that is thermodynamically unstable in the chaperone-free equilibrium. Here we present a model of Hsp70-mediated protein folding, which predicts that Hsp70, as a result of differential stimulation of ATP hydrolysis by its Hsp40 cochaperone, dissociates faster from a substrate in fold-competent conformations than from one in misfolding-prone conformations, thus elevating the native concentration above and suppressing the misfolded concentration below their respective equilibrium values. Previous models would not make or imply these predictions, which are experimentally testable. Our model quantitatively reproduces experimental refolding kinetics, predicts how modulations of the Hsp70/Hsp40 chaperone system affect protein folding, and suggests new approaches to regulating cellular protein quality.

Neuronal DnaJ proteins HSJ1a and HSJ1b: a role in linking the Hsp70 chaperone machine to the ubiquitin–proteasome system?

2004 ◽  
Vol 32 (4) ◽  
pp. 640-642 ◽  
Author(s):  
J.P. Chapple ◽  
J. van der Spuy ◽  
S. Poopalasundaram ◽  
M.E. Cheetham
Keyword(s):  
Protein Folding ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Protein 70 ◽  
Ubiquitin Proteasome System ◽  
Cellular Protein ◽  
Hsp70 Chaperone ◽  
Ubiquitin Proteasome ◽  
Cellular Processing

The heat-shock protein 70 chaperone machine is functionally connected to the ubiquitin–proteasome system by the co-chaperone CHIP. In this article, we discuss evidence that the neuronal DnaJ proteins HSJ1a and HSJ1b may represent a further link between the cellular protein folding and degradation machineries. We have demonstrated that HSJ1 proteins contain putative ubiquitin interaction motifs and can modulate the cellular processing of rhodopsin, a protein that is targeted for degradation by the proteasome when it is misfolded.

scholarly journals Stimulation of the Human Heat Shock Protein 70 Promoter in Vitro by Simian Virus 40 Large T Antigen

1989 ◽  
Vol 264 (27) ◽  
pp. 16160-16164
Author(s):  
I C Taylor ◽  
W Solomon ◽  
B M Weiner ◽  
E Paucha ◽  
M Bradley ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Protein 70 ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Large T Antigen ◽  
Human Heat Shock Protein ◽  
Stimulation Of

Principles of chaperone-mediated protein folding

1995 ◽  
Vol 348 (1323) ◽  
pp. 107-112 ◽  
Keyword(s):  
Protein Folding ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Molecular Chaperones ◽  
Cellular Protein ◽  
Chaperone Proteins ◽  
Shock Proteins ◽  
Polypeptide Chains

The recent discovery of molecular chaperones and their functions has changed dramatically our view of the processes underlying the folding of proteins in vivo . Rather than folding spontaneously, most newly synthesized polypeptide chains seem to acquire their native conformations in a reaction mediated by chaperone proteins. Different classes of molecular chaperones, such as the members of the Hsp70 and Hsp60 families of heat-shock proteins, cooperate in a coordinated pathway of cellular protein folding.

Adenovirus E1A requires synthesis of a cellular protein to establish a stable transcription complex in injected Xenopus laevis oocytes

1987 ◽  
Vol 7 (9) ◽  
pp. 3049-3056
Author(s):  
J D Richter ◽  
H C Hurst ◽  
N C Jones
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Protein 70 ◽  
Mammalian Cells ◽  
Cellular Protein ◽  
Xenopus Laevis Oocytes ◽  
Protein Synthesis Inhibitors ◽  
Adenovirus E1a ◽  
High Level

The Escherichia coli-expressed adenovirus E1A 13S mRNA product injected into Xenopus oocytes was active, as assessed by its ability to stimulate the transcription of an injected gene which is normally responsive to E1A in mammalian cells. In the presence of the protein synthesis inhibitors pactamycin or cycloheximide, E1A was correctly posttranslationally modified (phosphorylated) and transported to the nucleus; but it failed to stimulate the transcription of an injected gene containing the human heat shock protein 70 promoter. The basal (unstimulated) level of transcription of the gene was unaffected by these inhibitors. If oocytes were cultured in the presence of cycloheximide after E1A stimulated transcription, however, the high level of transcription was maintained for several hours without new protein synthesis. Results of competition studies with the same promoter (the heat shock protein 70 promoter) linked to two marked genes demonstrated that once the induction of transcription by E1A took place, the stimulated levels of transcription were maintained, even when they were challenged with excess competitor DNA. Results of these studies suggest that E1A requires the synthesis of a cellular protein to form a stable transcription complex.

scholarly journals Heat shock stimulation of a tilapia heat shock protein 70 promoter is mediated by a distal element

2001 ◽  
Vol 356 (2) ◽  
pp. 353 ◽  
Author(s):  
Alfredo MOLINA ◽  
Emmanuel Di MARTINO ◽  
Joseph A. MARTIAL ◽  
Marc MULLER
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Protein 70 ◽  
Stimulation Of

scholarly journals Adenovirus E1A requires synthesis of a cellular protein to establish a stable transcription complex in injected Xenopus laevis oocytes.

1987 ◽  
Vol 7 (9) ◽  
pp. 3049-3056 ◽  
Author(s):  
J D Richter ◽  
H C Hurst ◽  
N C Jones
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Protein 70 ◽  
Mammalian Cells ◽  
Cellular Protein ◽  
Xenopus Laevis Oocytes ◽  
Protein Synthesis Inhibitors ◽  
Adenovirus E1a ◽  
High Level

The Escherichia coli-expressed adenovirus E1A 13S mRNA product injected into Xenopus oocytes was active, as assessed by its ability to stimulate the transcription of an injected gene which is normally responsive to E1A in mammalian cells. In the presence of the protein synthesis inhibitors pactamycin or cycloheximide, E1A was correctly posttranslationally modified (phosphorylated) and transported to the nucleus; but it failed to stimulate the transcription of an injected gene containing the human heat shock protein 70 promoter. The basal (unstimulated) level of transcription of the gene was unaffected by these inhibitors. If oocytes were cultured in the presence of cycloheximide after E1A stimulated transcription, however, the high level of transcription was maintained for several hours without new protein synthesis. Results of competition studies with the same promoter (the heat shock protein 70 promoter) linked to two marked genes demonstrated that once the induction of transcription by E1A took place, the stimulated levels of transcription were maintained, even when they were challenged with excess competitor DNA. Results of these studies suggest that E1A requires the synthesis of a cellular protein to form a stable transcription complex.

Mechanism of substrate recognition by Hsp70 chaperones

2004 ◽  
Vol 32 (4) ◽  
pp. 617-621 ◽  
Author(s):  
A. Erbse ◽  
M.P. Mayer ◽  
B. Bukau
Keyword(s):  
Protein Folding ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Protein 70 ◽  
Substrate Recognition ◽  
Short Peptide ◽  
Protein Substrates

The role of Hsp70 (heat-shock protein 70) chaperones in assisting protein-folding processes relies on their ability to associate with short peptide stretches of protein substrates in a transient and ATP-controlled manner. In the present study, we review the molecular details of the mechanism behind substrate recognition by Hsp70 proteins.

scholarly journals First-passage times in protein folding: exploring the native-like states vs. overcoming the free energy barrier

2021 ◽  
Author(s):  
Sergei F. Chekmarev
Keyword(s):  
Free Energy ◽  
Protein Folding ◽  
Energy Barrier ◽  
First Passage Time ◽  
Passage Time ◽  
Free Energy Barrier ◽  
Native State ◽  
First Passage ◽  
Single Exponential ◽  
Passage Times

All first-passage time distributions are essentially single-exponential. The first-passage time to reach the native state may be determined by the time to find the native state among native-like ones.

Sign in / Sign up

Export Citation Format

Share Document