The universe of Hsp90

2012 ◽  
Vol 3 (1) ◽  
pp. 79-97 ◽  
Author(s):  
Marta Stankiewicz ◽  
Matthias P. Mayer
Keyword(s):  
Posttranslational Modifications ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Special Role ◽  
Regulatory Circuits ◽  
Health And Disease ◽  
Client Proteins ◽  
Essential Function ◽  
Shock Proteins

AbstractMolecular chaperones are key components in the maintenance of cellular homeostasis and survival, not only during stress but also under optimal growth conditions. Among the ATP-dependent chaperones, heat shock proteins (Hsp90) proteins play a special role. While Hsp90s can interact with unfolded and misfolded proteins, their main (and in eukaryotic cells essential) function appears to involve interactions with a limited number of protein clients at late steps of maturation or in “alter-native” conformations for regulating their stability and activity. Because Hsp90 clients are hubs of diverse signaling networks and participate in nearly every cellular function, Hsp90s interconnect many regulatory circuits and link them to environmental impacts. The availability and activity of Hsp90 may thus influence complex physiological and pathophysiological processes, such as differentiation, development, aging, cancer, neurodegeneration, and infectious diseases. Furthermore, through homeostatic effects on differentiation and development, Hsp90s act as capacitors of phenotypic evolution. In this review, we discuss recent insights in the structure and chaperone cycle of Hsp90s, the mechanisms underlying Hsp90 binding to clients, and potential reasons why client proteins specifically require the assistance of Hsp90s. Moreover, the current views on Hsp90-cochaperone interactions and regulation of Hsp90 proteins via posttranslational modifications are summarized. The second half of this article is devoted to the role of Hsp90 proteins in health and disease, aging, and evolution.

Thermal Adaptation in CHO Cells at 40°C: The Influence of Growth Conditions and the Role of Heat Shock Proteins

1986 ◽  
Vol 107 (3) ◽  
pp. 317 ◽  
Author(s):  
Ewa Przybytkowski ◽  
Jason H. T. Bates ◽  
Diana A. Bates ◽  
William J. MacKillop
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Cho Cells ◽  
Thermal Adaptation ◽  
Growth Conditions ◽  
Shock Proteins

scholarly journals Molecular Chaperones ofLeishmania: Central Players in Many Stress-Related and -Unrelated Physiological Processes

2015 ◽  
Vol 2015 ◽  
pp. 1-21 ◽  
Author(s):  
Jose M. Requena ◽  
Ana M. Montalvo ◽  
Jorge Fraga
Keyword(s):  
Molecular Chaperones ◽  
Current Knowledge ◽  
Intracellular Localization ◽  
Nutrient Deficiency ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Structural Features ◽  
Insect Vector ◽  
And Shifts ◽  
Shock Proteins

Molecular chaperones are key components in the maintenance of cellular homeostasis and survival, not only during stress but also under optimal growth conditions. Folding of nascent polypeptides is supported by molecular chaperones, which avoid the formation of aggregates by preventing nonspecific interactions and aid, when necessary, the translocation of proteins to their correct intracellular localization. Furthermore, when proteins are damaged, molecular chaperones may also facilitate their refolding or, in the case of irreparable proteins, their removal by the protein degradation machinery of the cell. During their digenetic lifestyle,Leishmaniaparasites encounter and adapt to harsh environmental conditions, such as nutrient deficiency, hypoxia, oxidative stress, changing pH, and shifts in temperature; all these factors are potential triggers of cellular stress. We summarize here our current knowledge on the main types of molecular chaperones inLeishmaniaand their functions. Among them, heat shock proteins play important roles in adaptation and survival of this parasite against temperature changes associated with its passage from the poikilothermic insect vector to the warm-blooded vertebrate host. The study of structural features and the function of chaperones inLeishmaniabiology is providing opportunities (and challenges) for drug discovery and improving of current treatments against leishmaniasis.

scholarly journals METALLOTHIONEINS AS SENSORS AND CONTROLS EXCHANGE OF METALS IN THE CELLS

2014 ◽  
Vol 13 (3) ◽  
pp. 91-99 ◽  
Author(s):  
V. A. Kutyakov ◽  
A. V. Salmina
Keyword(s):  
Stress Factors ◽  
Special Role ◽  
Cellular Functions ◽  
Regulation Of Expression ◽  
Wide Range ◽  
Health And Disease ◽  
Pharmacology And Toxicology ◽  
Regulatory Functions ◽  
The Impact

The basic information on the classification, structure, induction and degradation, functions of the protein family – metallothionein (MT), including CNS in health and disease are presented in this review. It was found that four major isoforms of metallothionein perform different biological roles, are localized in dif- ferent tissues. Induction of MT is a universal reaction to the impact of a variety of stress factors. In recent years, understanding of the role of metallothioneins in metal homeostasis in the tissues in normal and pathological conditions have changed significantly. Notes polyfunctionality metallothioneins (transport of metal ions, maintaining redox reactions, tread, signal, modulated and regulatory functions) and their im- pact on basic cellular functions such as proliferation, differentiation, programmed cell death. Further- more, a special role is shown MT in the pathogenesis of cardiovascular, neurodegenerative and neoplastic disorders.Currently, these molecules are increasingly considered as potential targets for therapy of a wide range of diseases and the development of targeted approaches to the regulation of expression of MT – one of the promising areas of pharmacology and toxicology. Stressed the safety of metallothioneins as therapeutic agents.

scholarly journals The essential function of Swc4p - a protein shared by two chromatin-modifying complexes of the yeast Saccharomyces cerevisiae - resides within its N-terminal part.

2008 ◽  
Vol 55 (3) ◽  
pp. 603-612 ◽  
Author(s):  
Arkadiusz Miciałkiewicz ◽  
Anna Chełstowska
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Essential Gene ◽  
Random Mutagenesis ◽  
Growth Conditions ◽  
Histone H2a ◽  
Terminal Part ◽  
Yeast Saccharomyces Cerevisiae ◽  
Chromatin Remodeling Complexes ◽  
Essential Function

The Swc4p protein, encoded by an essential gene, is shared by two chromatin-remodeling complexes in Saccharomyces cerevisiae cells: NuA4 (nucleosome acetyltransferase of H4) and SWR1. The SWR1 complex catalyzes ATP-dependent exchange of the nucleosomal histone H2A for H2AZ (Htz1p). The activity of NuA4 is responsible mainly for the acetylation of the H4 histone but also for the acetylation of H2A and H2AZ. In this work we investigated the role of the Swc4p protein. Using random mutagenesis we isolated a collection of swc4 mutants and showed that the essential function of Swc4p resides in its N-terminal part, within the first 269 amino acids of the 476-amino acid-long protein. We also demonstrated that Swc4p is able to accommodate numerous mutations without losing its functionality under standard growth conditions. However, when swc4 mutants were exposed to methyl methanesulfonate (MMS), hydroxyurea or benomyl, severe growth deficiencies appeared, pointing to an involvement of Swc4p in many chromatin-based processes. The mutants' phenotypes did not result from an impairment of histone acetylation, as in the mutant which bears the shortest isolated variant of truncated Swc4p, the level of overall H4 acetylation was unchanged.

scholarly journals Heat Shock Proteins in Glioblastoma Biology: Where Do We Stand?

2019 ◽  
Vol 20 (22) ◽  
pp. 5794 ◽  
Author(s):  
Rebeca Piatniczka Iglesia ◽  
Camila Felix de Lima Fernandes ◽  
Bárbara Paranhos Coelho ◽  
Mariana Brandão Prado ◽  
Maria Isabel Melo Escobar ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Cell Types ◽  
Current Evidence ◽  
Health And Disease ◽  
Shock Proteins ◽  
Mitochondrial Chaperones ◽  
Different Cell Types ◽  
Small Subpopulation

Heat shock proteins (HSPs) are evolutionary conserved proteins that work as molecular chaperones and perform broad and crucial roles in proteostasis, an important process to preserve the integrity of proteins in different cell types, in health and disease. Their function in cancer is an important aspect to be considered for a better understanding of disease development and progression. Glioblastoma (GBM) is the most frequent and lethal brain cancer, with no effective therapies. In recent years, HSPs have been considered as possible targets for GBM therapy due their importance in different mechanisms that govern GBM malignance. In this review, we address current evidence on the role of several HSPs in the biology of GBMs, and how these molecules have been considered in different treatments in the context of this disease, including their activities in glioblastoma stem-like cells (GSCs), a small subpopulation able to drive GBM growth. Additionally, we highlight recent works that approach other classes of chaperones, such as histone and mitochondrial chaperones, as important molecules for GBM aggressiveness. Herein, we provide new insights into how HSPs and their partners play pivotal roles in GBM biology and may open new therapeutic avenues for GBM based on proteostasis machinery.

Effects of neuronal drebrin on actin dynamics

2021 ◽  
Author(s):  
Elena E. Grintsevich
Keyword(s):  
Synaptic Plasticity ◽  
Posttranslational Modifications ◽  
Neurodegenerative Disorders ◽  
Neuronal Migration ◽  
Recent Progress ◽  
Actin Dynamics ◽  
Cytoskeletal Dynamics ◽  
Health And Disease ◽  
Made In

Drebrin is a key regulator of actin cytoskeleton in neuronal cells which is critical for synaptic plasticity, neuritogenesis, and neuronal migration. It is also known to orchestrate a cross-talk between actin and microtubules. Decreased level of drebrin is a hallmark of multiple neurodegenerative disorders such as Alzheimer's disease. Despite its established importance in health and disease, we still have a lot to learn about drebrin's interactome and its effects on cytoskeletal dynamics. This review aims to summarize the recently reported novel effects of drebrin on actin and its regulators. Here I will also reflect on the most recent progress made in understanding of the role of drebrin isoforms and posttranslational modifications on its functionality.

scholarly journals Potentials of Microorganisms in Human Health

2021 ◽  
pp. 1-9
Author(s):  
Ali Mohamed Elshafei
Keyword(s):  
Autoimmune Diseases ◽  
Human Health ◽  
Metabolic Diseases ◽  
Human Microbiome ◽  
Food Products ◽  
Growth Conditions ◽  
Large Numbers ◽  
Close Relationship ◽  
Health And Disease

There are large numbers of powerful species of microorganisms present within our bodies that make up the diverse human microbiomes. Microbiomes, the collective genomes of the microorganisms in a particular environment, support and maintain our health, but they are disturbed in some fashion in case of the presence of some diseases such as autoimmune diseases and cancer. Different food products provide different growth conditions for microorganisms. Microbial growth is also controlled by some factors such as pH, nutrients, moisture content, temperature, relative humidity, and gases. Thus the growth of microorganisms in optimum conditions results in spoilage and degradation of food products resulting in a sour or foul-smelling, in addition to a visible change in color, effervescences on the food surface, etc. Microbial contamination of food can occur at any point in the food production process starting from growth, harvesting, transport, storage, or final preparation. A variety of environmental factors can influence intestinal microbial imbalance, which has a close relationship with human health and disease. There are many numerous potential probiotics or beneficial bacteria that may prevent or treat certain diseases such as Lactobacillus and Bifidobacterium. On the other hand, a few destructive microorganisms play a major role in the development and progression of major human diseases such as infectious diseases, liver diseases, gastrointestinal cancers, metabolic diseases, respiratory diseases, mental or psychological diseases, and autoimmune diseases. With the increased understanding of the relationship between the human microbiome and a variety of diseases, the use of these findings to predict or diagnose diseases has attracted a great deal of attention. Thus, the aim of the present work was to review briefly the role of microorganisms in human health, during the development of autoimmune and tumor diseases. This review article also includes microbiota diversity, colonization, and normalization of perturbed intestinal microbial communities, the safety of gastrointestinal tract, and the beneficial role of probiotics.

scholarly journals Role of Heat-Shock Proteins in Cellular Function and in the Biology of Fungi

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Shraddha Tiwari ◽  
Raman Thakur ◽  
Jata Shankar
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Posttranslational Modifications ◽  
Biological Processes ◽  
Current Review ◽  
Hsp60 Expression ◽  
Response To Stress ◽  
Aggregation And Disaggregation ◽  
Shock Proteins

Stress (biotic or abiotic) is an unfavourable condition for an organism including fungus. To overcome stress, organism expresses heat-shock proteins (Hsps) or chaperons to perform biological function. Hsps are involved in various routine biological processes such as transcription, translation and posttranslational modifications, protein folding, and aggregation and disaggregation of proteins. Thus, it is important to understand holistic role of Hsps in response to stress and other biological conditions in fungi. Hsp104, Hsp70, and Hsp40 are found predominant in replication and Hsp90 is found in transcriptional and posttranscriptional process. Hsp90 and Hsp70 in combination or alone play a major role in morphogenesis and dimorphism. Heat stress in fungi expresses Hsp60, Hsp90, Hsp104, Hsp30, and Hsp10 proteins, whereas expression of Hsp12 protein was observed in response to cold stress. Hsp30, Hsp70, and Hsp90 proteins showed expression in response to pH stress. Osmotic stress is controlled by small heat-shock proteins and Hsp60. Expression of Hsp104 is observed under high pressure conditions. Out of these heat-shock proteins, Hsp90 has been predicted as a potential antifungal target due to its role in morphogenesis. Thus, current review focuses on role of Hsps in fungi during morphogenesis and various stress conditions (temperature, pH, and osmotic pressure) and in antifungal drug tolerance.

scholarly journals Spermidine Acetyltransferase Is Required To Prevent Spermidine Toxicity at Low Temperatures in Escherichia coli

2000 ◽  
Vol 182 (19) ◽  
pp. 5373-5380 ◽  
Author(s):  
Kornvika Limsuwun ◽  
Pamela G. Jones
Keyword(s):  
Escherichia Coli ◽  
Protein Synthesis ◽  
Low Temperature ◽  
Low Temperatures ◽  
Cold Shock ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Cellular Growth ◽  
Ribosome Inactivation ◽  
Shock Proteins

ABSTRACT Polyamines are required for optimal growth in most cells; however, polyamine accumulation leads to inhibition of cellular growth. To reduce intracellular polyamine levels, spermidine is monoacetylated in both prokaryotes and eukaryotes. In Escherichia coli, thespeG gene encodes the spermidine acetyltransferase, which transfers the acetyl group to either the N-1 or N-8 position. In addition to polyamine accumulation, stress conditions, such as cold shock, cause an increase in the level of spermidine acetylation, suggesting an adaptive role for reduced polyamine levels under stressful growth conditions. The effect of spermidine accumulation on the growth of E. coli at low temperature was examined using a speG mutant. At 37°C, growth of the speGmutant was normal in the presence of 0.5 or 1 mM spermidine. However, following a shift to 7°C, the addition of 0.5 or 1 mM spermidine resulted in inhibition of cellular growth or cell lysis, respectively. Furthermore, at 7°C, spermidine accumulation resulted in a decrease in total protein synthesis accompanied by an increase in the synthesis of the major cold shock proteins CspA, CspB, and CspG. However, the addition of 50 mM Mg2+ restored growth and protein synthesis in the presence of 0.5 mM spermidine. The results indicate that the level of spermidine acetylation increases at low temperature to prevent spermidine toxicity. The data suggest that the excess spermidine replaces the ribosome-bound Mg2+, resulting in ribosome inactivation at low temperatures.

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