scholarly journals The balance between protein folding and aggregation in the early stages of a protein’s life: role of the ribosome and molecular chaperones (752.6)

2014 ◽  
Vol 28 (S1) ◽  
Author(s):  
Yue Liu ◽  
Silvia Cavagnero
Keyword(s):  
Protein Folding ◽  
Molecular Chaperones ◽  
Early Stages

scholarly journals Teasing Apart the Role of the Ribosome and Molecular Chaperones in Cellular Protein Folding

2018 ◽  
Vol 114 (3) ◽  
pp. 414a
Author(s):  
Rayna M. Addabbo ◽  
Matthew D. Dalphin ◽  
Yue Liu ◽  
Miranda F. Mecha ◽  
Silvia Cavagnero
Keyword(s):  
Protein Folding ◽  
Molecular Chaperones ◽  
Cellular Protein

Role of Molecular Chaperones in Protein Folding

2010 ◽  
pp. 47-72 ◽  
Author(s):  
Kausik Chakraborty ◽  
Florian Georgescauld ◽  
Manajit Hayer-Hartl ◽  
F. Ulrich Hartl
Keyword(s):  
Protein Folding ◽  
Molecular Chaperones

The role of molecular chaperones in protein folding.

1995 ◽  
Vol 9 (15) ◽  
pp. 1559-1569 ◽  
Author(s):  
J P Hendrick ◽  
F U Hartl
Keyword(s):  
Protein Folding ◽  
Molecular Chaperones

scholarly journals A Nonconventional Role of Molecular Chaperones: Involvement in the Cytoarchitecture

Physiology ◽  
2001 ◽  
Vol 16 (3) ◽  
pp. 123-126 ◽  
Author(s):  
Peter Csermely
Keyword(s):  
Protein Folding ◽  
Molecular Chaperones ◽  
Eukaryotic Cells ◽  
Intracellular Traffic

A hallmark of chaperone action is assistance in protein folding. Indeed, folding of nascent prokaryotic proteins proceeds mostly as a chaperone-assisted, posttranslational event. On the contrary, in nonstressed eukaryotic cells folding-related tasks of eukaryotic chaperones are restricted to a subset of proteins, and “jobless” chaperones may form an extension of the cytoarchitecture, facilitating intracellular traffic of proteins and other macromolecules.

scholarly journals Protein Disulfide Isomerase Superfamily in Disease and the Regulation of Apoptosis

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
C. Grek ◽  
D.M. Townsend
Keyword(s):  
Protein Folding ◽  
Er Stress ◽  
Cell Fate ◽  
Molecular Chaperones ◽  
Molecular Mechanisms ◽  
Disulfide Isomerases ◽  
Apoptotic Pathways ◽  
Er Homeostasis ◽  
Protein Disulfide

AbstractCellular homeostasis requires the balance of a multitude of signaling cascades that are contingent upon the essential proteins being properly synthesized, folded and delivered to appropriate subcellular locations. In eukaryotic cells the endoplasmic reticulum (ER) is a specialized organelle that is the central site of synthesis and folding of secretory, membrane and a number of organelletargeted proteins. The integrity of protein folding is enabled by the presence of ATP, Ca++, molecular chaperones, as well as an oxidizing redox environment. The imbalance between the load and capacity of protein folding results in a cellular condition known as ER stress. Failure of these pathways to restore ER homeostasis results in the activation of apoptotic pathways. Protein disulfide isomerases (PDI) compose a superfamily of oxidoreductases that have diverse sequences and are localized in the ER, nucleus, cytosol, mitochondria and cell membrane. The PDI superfamily has multiple functions including, acting as molecular chaperones, protein-binding partners, and hormone reservoirs. Recently , PDI family members have been implicated in the regulation of apoptotic signaling events. The complexities underlying the molecular mechanisms that define the switch from pro-survival to pro-death response are evidenced by recent studies that reveal the roles of specific chaperone proteins as integration points in signaling pathways that determine cell fate. The following review discusses the dual role of PDI in cell death and survival during ER stress.

scholarly journals Cyclophilin 20 is involved in mitochondrial protein folding in cooperation with molecular chaperones Hsp70 and Hsp60.

1995 ◽  
Vol 15 (5) ◽  
pp. 2654-2662 ◽  
Author(s):  
J Rassow ◽  
K Mohrs ◽  
S Koidl ◽  
I B Barthelmess ◽  
N Pfanner ◽  
...  
Keyword(s):  
Protein Folding ◽  
Cyclosporin A ◽  
Molecular Chaperones ◽  
Mitochondrial Protein ◽  
The Matrix ◽  
Inhibitory Drug ◽  
Preprotein Translocation ◽  
Cellular Compartments ◽  
Precursor Molecules

We studied the role of mitochondrial cyclophilin 20 (CyP20), a peptidyl-prolyl cis-trans isomerase, in preprotein translocation across the mitochondrial membranes and protein folding inside the organelle. The inhibitory drug cyclosporin A did not impair membrane translocation of preproteins, but it delayed the folding of an imported protein in wild-type mitochondria. Similarly, Neurospora crassa mitochondria lacking CyP20 efficiently imported preproteins into the matrix, but folding of an imported protein was significantly delayed, indicating that CyP20 is involved in protein folding in the matrix. The slow folding in the mutant mitochondria was not inhibited by cyclosporin A. Folding intermediates of precursor molecules reversibly accumulated at the molecular chaperones Hsp70 and Hsp60 in the matrix. We conclude that CyP20 is a component of the mitochondrial protein folding machinery and that it cooperates with Hsp70 and Hsp60. It is speculated that peptidyl-prolyl cis-trans isomerases in other cellular compartments may similarly promote protein folding in cooperation with chaperone proteins.

Chaperone-Mediated Protein Folding

1999 ◽  
Vol 79 (2) ◽  
pp. 425-449 ◽  
Author(s):  
Anthony L. Fink
Keyword(s):  
Protein Folding ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Molecular Chaperones ◽  
Main Role ◽  
Detailed Understanding ◽  
Substrate Protein ◽  
Reaction Cycles ◽  
Polypeptide Chains

The folding of most newly synthesized proteins in the cell requires the interaction of a variety of protein cofactors known as molecular chaperones. These molecules recognize and bind to nascent polypeptide chains and partially folded intermediates of proteins, preventing their aggregation and misfolding. There are several families of chaperones; those most involved in protein folding are the 40-kDa heat shock protein (HSP40; DnaJ), 60-kDa heat shock protein (HSP60; GroEL), and 70-kDa heat shock protein (HSP70; DnaK) families. The availability of high-resolution structures has facilitated a more detailed understanding of the complex chaperone machinery and mechanisms, including the ATP-dependent reaction cycles of the GroEL and HSP70 chaperones. For both of these chaperones, the binding of ATP triggers a critical conformational change leading to release of the bound substrate protein. Whereas the main role of the HSP70/HSP40 chaperone system is to minimize aggregation of newly synthesized proteins, the HSP60 chaperones also facilitate the actual folding process by providing a secluded environment for individual folding molecules and may also promote the unfolding and refolding of misfolded intermediates.

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