The Hsp70 Molecular Chaperone Machines

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The Hsp70 Molecular Chaperone Machines

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Author : Matthias P. Mayer
language : en
Publisher: Frontiers Media SA
Release Date : 2017-03-24

The Hsp70 Molecular Chaperone Machines written by Matthias P. Mayer and has been published by Frontiers Media SA this book supported file pdf, txt, epub, kindle and other format this book has been release on 2017-03-24 with Electronic book categories.

Members of the HSP70 family form a central hub of the molecular chaperone network, controlling protein homeostasis in prokaryotes and in the ATP-containing compartments of the eukaryotic cells. The heat-inducible form HSPA1A (HSP70), its constitutive cytosolic cognate HSPA8 (Hsc70), its endoplasmic reticulum form HSPA5 (BiP), and its mitochondrial form HSPA9 (Mortalin), as well as the more distantly related HSPHs (HSP110s), make up 1-2 % of the total mass of proteins in human cells. They use the energy of ATP-hydrolysis to prevent and forcefully revert the process of protein misfolding and aggregation during and following various stresses, presumably by working as unfoldases to lift aberrant conformers out of kinetic traps. As such, HSP70s, in cooperation with their J-domain co-chaperones and nucleotide exchange factors (NEFs) and co-disaggregases, form an efficient network of cellular defenses against the accumulation of cytotoxic misfolded protein conformers, which may cause degenerative diseases such as Parkinson's and Alzheimer's disease, diabetes, and aging in general. In addition to their function in repair of stress-induced damage, HSP70s fulfill many housekeeping functions, including assisting the de novo folding and maturation of proteins, driving the translocation of protein precursors across narrow membrane pores into organelles, and by controlling the oligomeric state of key regulator protein complexes involved in signal transduction and vesicular trafficking. For reasons not well understood, HSP70s are also found on the surface of some animal cells, in particular cancer cells where they may serve as specific targets for cancer immunotherapy. Here, we gathered seven mini reviews, each presenting a complementary aspect of HSP70’s structure and function in bacteria and eukaryotes, under physiological and stressful conditions. These articles highlight how, the various members of this conserved family of molecular chaperones, assisted by their various J-domain and NEF cochaperones and co-disaggregases, harness ATP hydrolysis to perform a great diversity of life-sustaining cellular functions using a similar molecular mechanism.

The Hsp70 Molecular Chaperone Machines

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Author :
language : en
Publisher:
Release Date : 2017

The Hsp70 Molecular Chaperone Machines written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2017 with categories.

Members of the HSP70 family form a central hub of the molecular chaperone network, controlling protein homeostasis in prokaryotes and in the ATP-containing compartments of the eukaryotic cells. The heat-inducible form HSPA1A (HSP70), its constitutive cytosolic cognate HSPA8 (Hsc70), its endoplasmic reticulum form HSPA5 (BiP), and its mitochondrial form HSPA9 (Mortalin), as well as the more distantly related HSPHs (HSP110s), make up 1-2 % of the total mass of proteins in human cells. They use the energy of ATP-hydrolysis to prevent and forcefully revert the process of protein misfolding and aggregation during and following various stresses, presumably by working as unfoldases to lift aberrant conformers out of kinetic traps. As such, HSP70s, in cooperation with their J-domain co-chaperones and nucleotide exchange factors (NEFs) and co-disaggregases, form an efficient network of cellular defenses against the accumulation of cytotoxic misfolded protein conformers, which may cause degenerative diseases such as Parkinson's and Alzheimer's disease, diabetes, and aging in general. In addition to their function in repair of stress-induced damage, HSP70s fulfill many housekeeping functions, including assisting the de novo folding and maturation of proteins, driving the translocation of protein precursors across narrow membrane pores into organelles, and by controlling the oligomeric state of key regulator protein complexes involved in signal transduction and vesicular trafficking. For reasons not well understood, HSP70s are also found on the surface of some animal cells, in particular cancer cells where they may serve as specific targets for cancer immunotherapy. Here, we gathered seven mini reviews, each presenting a complementary aspect of HSP70's structure and function in bacteria and eukaryotes, under physiological and stressful conditions. These articles highlight how, the various members of this conserved family of molecular chaperones, assisted by their various J-domain and NEF cochaperones and co-disaggregases, harness ATP hydrolysis to perform a great diversity of life-sustaining cellular functions using a similar molecular mechanism.

Structure And Action Of Molecular Chaperones

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Author : Lila M Gierasch
language : en
Publisher: World Scientific
Release Date : 2016-08-08

Structure And Action Of Molecular Chaperones written by Lila M Gierasch and has been published by World Scientific this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016-08-08 with Science categories.

This unique volume reviews the beautiful architectures and varying mechanical actions of the set of specialized cellular proteins called molecular chaperones, which provide essential kinetic assistance to processes of protein folding and unfolding in the cell. Ranging from multisubunit ring-shaped chaperonin and Hsp100 machines that use their central cavities to bind and compartmentalize action on proteins, to machines that use other topologies of recognition — binding cellular proteins in an archway or at the surface of a "clamp" or at the surface of a globular assembly — the structures show us the ways and means the cell has devised to assist its major effectors, proteins, to reach and maintain their unique active forms, as well as, when required, to disrupt protein structure in order to remodel or degrade. Each type of chaperone is beautifully illustrated by X-ray and EM structure determinations at near- atomic level resolution and described by a leader in the study of the respective family. The beauty of what Mother Nature has devised to accomplish essential assisting actions for proteins in vivo is fully appreciable.

Protein Folding And Aggregation In The Presence Of The Hsp70 Chaperone

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Author : Miranda F. Mecha
language : en
Publisher:
Release Date : 2021

Protein Folding And Aggregation In The Presence Of The Hsp70 Chaperone written by Miranda F. Mecha and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2021 with categories.

Most life on earth depends on ribosome-assisted biosynthesis and on the generation and preservation of correct protein structure. Molecular chaperones and their cochaperones act co- and post-translationally to promote de novo protein folding, overcome protein damage upon stress and even disaggregate protein aggregates. Hsp70, a ubiquitous and highly conserved 70 kDa heat shock protein, is a particularly important and well-studied chaperone. It is often referred to as a central "hub" due to its myriad of functions and its profound effect on cell viability. While the Hsp70 chaperone cycle has been well-documented in the literature, there is still much to be understood about the interplay between Hsp70 and its client-proteins, including the kinetic and thermodynamic client-protein characteristics required for interaction with Hsp70. The Hsp70 chaperone is nucleotide-dependent and derives part of its driving force for assisting protein folding from ATP hydrolysis. The Hsp70-related studies carried out to date bear an apparent inconsistency. Namely, some proteins were reported to attain their native state more slowly in the presence of the Hsp70 chaperone than under chaperone-free conditions. On the other hand, aggregation-prone proteins routinely acquire a bioactive native state faster, in the presence of Hsp70. Part of the work carried out in this thesis attempts to explain this apparent inconsistency. In addition, we explore the kinetic and thermodynamic client-protein characteristics necessary for interaction with the Hsp70 chaperone. Finally, we address the relation between protein aging and Hsp70-chaperone activity.The thesis is divided into six chapters. Chapter 1 delves into the current literature and summarizes what is known about protein folding and how the folding process is influenced by the Hsp70 chaperone cycle. This chapter further discusses the structure and function of Hsp70 and how these characteristics affect the conformation and dynamics of chaperone-bound client proteins. The chapter also provides a brief overview of the current computational approaches to predict the timecourse of Hsp70-assisted protein folding. Chapter 2 focuses on the development of CHAMPION70, a computational model able to perform Chaperone-Mediated Protein folding kinetic Simulations involving Hsp70. We then apply CHAMPION70 to four classes of client proteins with different kinetic (fast- or slow-folding) and thermodynamic (stable or unstable) stabilities in the presence of either no aggregation, weak aggregation or strong aggregation propensities. We find that, in the absence of aggregation, unstable client proteins capture (i.e., stay bound to) the Hsp70 chaperone indefinitely. This is a clear disadvantage unless Hsp70 serves as a transport machine, for these proteins. Conversely, in the presence of weak or strong aggregation propensities, it is very beneficial for client-proteins to interact with the Hsp70 chaperone system. Specifically, slow-folding and thermodynamically stable client proteins experience the greatest aggregation-prevention advantages in the presence of Hsp70, especially if the class of client proteins is strongly aggregation-prone. However, Hsp70 is unable to assist the folding of strongly aggregation-prone and thermodynamically unstable proteins. Importantly, we also predict that the E. coli Hsp70 chaperone system is unable to prevent protein aggregation over long time spans long-term (i.e., greater than ca 60 years). This result suggests that one of the consequence of protein aging is the intrinsic failure of the bacterial Hsp70 chaperone machinery. Of course E. coli bacteria double in only a few minutes and "old proteins" likely persist in the progeny (i.e., daughter cells). Yet these old proteins progressively become more and more dilute, hence less-aggregation-prone. This phenomenon may rescue bacteria from disaster. Yet one wonders whether this effect may have a more severe impact on eukaryotic Hsp70s. In summary, the CHAMPION70 simulator is a powerful tool to enable the prediction of client-protein behavior in the presence of one of the most amazing cellular machines, the Hsp70 chaperone system. Chapter 3 provides simple computational tools to discriminate folded from intrinsically disordered proteins (IDPs) under physiologically relevant conditions, solely based on protein amino-acid composition. This tool only requires knowledge on protein hydrophobicity-per-residue and net-charge-per-residue. The net-charge-non-polar (NECNOP) algorithm results in 95% accuracy, and this value increases for proteins of more than 140 residues. Chapter 4 delves into influence of the E. coli ribosome on both co- and post-translational protein folding in the absence typical molecular chaperone systems (DnaK, trigger factor) and in the presence of aggregation. In this experimental investigation, translation through the ribosome is found to promote nascent-protein solubility even in the absence of cotranslationally active molecular chaperones. This work also shows that the E. coli trigger factor and DnaK molecular chaperones increase the solubility of nascent chains emerging from the ribosomal exit tunnel and minimize co- and post-translational aggregation. Most importantly, this work shows the importance of immediately post-translational kinetic partitioning of nascent proteins between native-state and aggregates, upon release form the ribosome. This partitioning is dramatically sensitive to subtle variations in amino-acid sequence, including single-point mutations. Chapter 5 demonstrates the increased sensitivity of the NMR hyperpolarization technique known as low-concentration photochemically induced dynamic nuclear polarization (LC-photo-CIDNP). This technique is used for detection of aromatic amino acids in the presence of both a photosensitizer dye (fluorescein) and a cryogenic probe. Experiments rapidly detect the amino acids tryptophan (Trp) and tyrosine (Tyr) at unprecedented concentrations (200 nM). Detection of the model protein drkN SH3 (which bears Trp, Tyr and His) at 500 nM on a 600 MHz spectrometer via LC-Photo-CIDNP leads to a 30-fold better S/N relative to conventional 2D experiments performed at higher magnetic field (900MHz spectrometer). Spectral editing of the model protein allowed for secondary and tertiary structure analysis. In contrast to regular photo-CIDNP, LC-photo-CIDNP does not heavily depend on laser intensity, thus allowing for safer and more cost-effective experiments. Chapter 6 further develops the investigations of Chapter 5 on LC-photo-CIDNP. A major limitation of LC-photo-CIDNP is that a limited number of scans (up to ca 200) can typically be collected before sample degradation takes over. The signal-to-noise (SN) ratio becomes progressively weaker as the number of scans increases. This disadvantage strongly limits the ability to perform long-term experiments. Two reductive radical quenchers - ascorbic acid (vitamin C) and 2-mercaptoethylamine (MEA) - were employed in this study, to minimize the extent of photodamage in NMR samples. This technique both enhanced the S/N by over 100% and allowed for more transients to be acquired for amino-acid and protein samples in solution.

The Networking Of Chaperones By Co Chaperones

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Author : Gregory L. Blatch
language : en
Publisher: Springer Science & Business Media
Release Date : 2010-06-07

The Networking Of Chaperones By Co Chaperones written by Gregory L. Blatch and has been published by Springer Science & Business Media this book supported file pdf, txt, epub, kindle and other format this book has been release on 2010-06-07 with Science categories.

The Networking of Chaperones by Co-chaperones updates the current understanding of how chaperones are regulated and networked. It is a resource for those in the specialized field of cell stress and chaperones. The book will also be of interest to those in broader cross-cutting field such as cellular networks and systems biology.

Molecular Chaperones

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Author : Sophie Jackson
language : en
Publisher: Springer
Release Date : 2012-12-15

Molecular Chaperones written by Sophie Jackson and has been published by Springer this book supported file pdf, txt, epub, kindle and other format this book has been release on 2012-12-15 with Science categories.

Assisting Oxidative Protein Folding: How Do Protein Disulphide-Isomerases Couple Conformational and Chemical Processes in Protein Folding?, by A. Katrine Wallis and Robert B. Freedman Peptide Bond cis/trans Isomerases: A Biocatalysis Perspective of Conformational Dynamics in Proteins, by Cordelia Schiene-Fischer, Tobias Aumüller and Gunter Fischer Small Heat-Shock Proteins: Paramedics of the Cell, by Gillian R. Hilton, Hadi Lioe, Florian Stengel, Andrew J. Baldwin und Justin L. P. Benesch Allostery in the Hsp70 Chaperone Proteins, by Erik R. P. Zuiderweg, Eric B. Bertelsen, Aikaterini Rousaki, Matthias P. Mayer, Jason E. Gestwicki and Atta Ahmad Hsp90: Structure and Function, by Sophie E. Jackson Extracellular Chaperones, by Rebecca A. Dabbs, Amy R. Wyatt, Justin J. Yerbury, Heath Ecroyd and Mark R. Wilson

Structural Organization Of The Hsp90 Hsp70 Based Chaperone Machinery And Its Interaction With The Glucocorticoid Receptor Ligand Binding Domain

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Author : Patrick J. M. Murphy
language : en
Publisher:
Release Date : 2003

Structural Organization Of The Hsp90 Hsp70 Based Chaperone Machinery And Its Interaction With The Glucocorticoid Receptor Ligand Binding Domain written by Patrick J. M. Murphy and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2003 with categories.

Molecular Chaperones Advances In Research And Application 2011 Edition

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Author :
language : en
Publisher: ScholarlyEditions
Release Date : 2012-01-09

Molecular Chaperones Advances In Research And Application 2011 Edition written by and has been published by ScholarlyEditions this book supported file pdf, txt, epub, kindle and other format this book has been release on 2012-01-09 with Science categories.

Molecular Chaperones: Advances in Research and Application: 2011 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Molecular Chaperones. The editors have built Molecular Chaperones: Advances in Research and Application: 2011 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Molecular Chaperones in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Molecular Chaperones: Advances in Research and Application: 2011 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

Hsf1 And Molecular Chaperones In Biology And Cancer

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Author : Marc Laurence Mendillo
language : en
Publisher: Springer Nature
Release Date : 2020-04-15

Hsf1 And Molecular Chaperones In Biology And Cancer written by Marc Laurence Mendillo and has been published by Springer Nature this book supported file pdf, txt, epub, kindle and other format this book has been release on 2020-04-15 with Medical categories.

Protein homeostasis, or “Proteostasis”, lies at the heart of human health and disease. From the folding of single polypeptide chains into functional proteins, to the regulation of intracellular signaling pathways, to the secreted signals that coordinate cells in tissues and throughout the body, the proteostasis network operates to support cell health and physiological fitness. However, cancer cells also hijack the proteostasis network and many of these same processes to sustain the growth and spread of tumors. The chapters in this book are written by world experts in the many facets of the proteostasis network. They describe cutting-edge insights into the structure and function of the major chaperone and degradation systems in healthy cells and how these systems are co-opted in cancer cells and the cells of the tumor microenvironment. The chapters also cover therapeutic interventions such as the FDA-approved proteasome inhibitors Velcade and Krypolis as well as other therapies currently under clinical investigation to disarm the ability of the proteostasis network to support malignancy. This compendium is the first of its kind and aims to serve as a reference manual for active investigators and a primer for newcomers to the field. This book is dedicated to the memory of Susan Lindquist, a pioneer of the proteostasis field and a champion of the power of basic scientific inquiry to unlock the mechanisms of human disease. The chapter “Reflections and Outlook on Targeting HSP90, HSP70 and HSF1 in Cancer: A Personal Perspective” is available open access under a Creative Commons Attribution 4.0 International License via link.springer.com.

Structure And Action Of Molecular Chaperones

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Author : Lila M. Gierasch
language : en
Publisher: World Scientific Publishing Company
Release Date : 2016

Structure And Action Of Molecular Chaperones written by Lila M. Gierasch and has been published by World Scientific Publishing Company this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016 with Molecular chaperones categories.

This unique volume reviews the beautiful architectures and varying mechanical actions of the set of specialized cellular proteins called molecular chaperones, which provide essential kinetic assistance to processes of protein folding and unfolding in the cell. Ranging from multisubunit ring-shaped chaperonin and Hsp100 machines that use their central cavities to bind and compartmentalize action on proteins, to machines that use other topologies of recognition -- binding cellular proteins in an archway or at the surface of a "clamp" or at the surface of a globular assembly -- the structures show us the ways and means the cell has devised to assist its major effectors, proteins, to reach and maintain their unique active forms, as well as, when required, to disrupt protein structure in order to remodel or degrade. Each type of chaperone is beautifully illustrated by X-ray and EM structure determinations at near- atomic level resolution and described by a leader in the study of the respective family. The beauty of what Mother Nature has devised to accomplish essential assisting actions for proteins in vivo is fully appreciable.