scholarly journals Clustering of heat-shock factors

2006 ◽  
Vol 395 (1) ◽  
Author(s):  
Johanna K. Björk ◽  
Lea Sistonen
Keyword(s):  
Heat Shock ◽  
Protein Accumulation ◽  
Heat Shock Factors ◽  
Exact Role ◽  
Unfolded Protein ◽  
Proteotoxic Stress ◽  
Trimeric Complex ◽  
Biochemical Journal ◽  
Cellular Defence

Clusterin is a ubiquitous glycoprotein found in most physiological fluids and tissues. Although not fully understood, the function of clusterin seems to be related to its ability to bind a wide variety of molecules. Since clusterin has been found associated with extracellular protein aggregates, a role as a molecular chaperone has been proposed. In this issue of the Biochemical Journal, Le Dréan and colleagues demonstrate an up-regulation of clusterin in neuronal cells exposed to proteotoxic stress that results in unfolded protein accumulation and proteasome impairment, both commonly associated with neurodegenerative diseases. Interestingly, expression of clusterin was found to be regulated by two members of the HSF (heat-shock factor) family, HSF1 and HSF2, which possibly form a trimeric complex on the clusterin promoter. The study proposes clusterin as a player in a cellular defence mechanism against harmful protein accumulation, and highlights the importance of elucidating further the exact role of clusterin and the intriguing interaction between HSF1 and HSF2.

Role of Heat Shock Factors in Diseases and Immunity

2020 ◽  
Author(s):  
Boopathi Balasubramaniam ◽  
Krishnaswamy Balamurugan
Keyword(s):  
Heat Shock ◽  
Heat Shock Factors

scholarly journals The role of class A1 heat shock factors (HSFA1s) in response to heat and other stresses in Arabidopsis

2011 ◽  
Vol 34 (5) ◽  
pp. 738-751 ◽  
Author(s):  
HSIANG-CHIN LIU ◽  
HSIU-TING LIAO ◽  
YEE-YUNG CHARNG
Keyword(s):  
Heat Shock ◽  
Heat Shock Factors

scholarly journals The autophagy receptor p62/SQST-1 promotes proteostasis and longevity in C. elegans by inducing autophagy

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Caroline Kumsta ◽  
Jessica T. Chang ◽  
Reina Lee ◽  
Ee Phie Tan ◽  
Yongzhi Yang ◽  
...  
Keyword(s):  
Heat Shock ◽  
Stress Responses ◽  
Dependent Manner ◽  
Selective Autophagy ◽  
C Elegans ◽  
Proteotoxic Stress ◽  
Autophagy Induction ◽  
The Impact ◽  
Lifespan Regulation

AbstractAutophagy can degrade cargos with the help of selective autophagy receptors such as p62/SQSTM1, which facilitates the degradation of ubiquitinated cargo. While the process of autophagy has been linked to aging, the impact of selective autophagy in lifespan regulation remains unclear. We have recently shown in Caenorhabditis elegans that transcript levels of sqst-1/p62 increase upon a hormetic heat shock, suggesting a role of SQST-1/p62 in stress response and aging. Here, we find that sqst-1/p62 is required for hormetic benefits of heat shock, including longevity, improved neuronal proteostasis, and autophagy induction. Furthermore, overexpression of SQST-1/p62 is sufficient to induce autophagy in distinct tissues, extend lifespan, and improve the fitness of mutants with defects in proteostasis in an autophagy-dependent manner. Collectively, these findings illustrate that increased expression of a selective autophagy receptor is sufficient to induce autophagy, enhance proteostasis and extend longevity, and demonstrate an important role for sqst-1/p62 in proteotoxic stress responses.

The molecular mechanism and potential role of heat shock-induced p53 protein accumulation

2013 ◽  
Vol 378 (1-2) ◽  
pp. 161-169 ◽  
Author(s):  
Juqiang Han ◽  
Xiaojie Xu ◽  
Hongzhen Qin ◽  
Anheng Liu ◽  
Zhongyi Fan ◽  
...  
Keyword(s):  
Heat Shock ◽  
Molecular Mechanism ◽  
Potential Role ◽  
P53 Protein ◽  
Protein Accumulation

scholarly journals TRAP1 in Oxidative Stress and Neurodegeneration

Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1829
Author(s):  
Inês Ramos Rego ◽  
Beatriz Santos Cruz ◽  
António Francisco Ambrósio ◽  
Celso Henrique Alves
Keyword(s):  
Oxidative Stress ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Redox Homeostasis ◽  
Tumor Necrosis Factor Receptor ◽  
Heat Shock Protein 90 ◽  
Special Focus ◽  
Receptor Associated Protein ◽  
Unfolded Protein

Tumor necrosis factor receptor-associated protein 1 (TRAP1), also known as heat shock protein 75 (HSP75), is a member of the heat shock protein 90 (HSP90) chaperone family that resides mainly in the mitochondria. As a mitochondrial molecular chaperone, TRAP1 supports protein folding and contributes to the maintenance of mitochondrial integrity even under cellular stress. TRAP1 is a cellular regulator of mitochondrial bioenergetics, redox homeostasis, oxidative stress-induced cell death, apoptosis, and unfolded protein response (UPR) in the endoplasmic reticulum (ER). TRAP1 has attracted increasing interest as a therapeutical target, with a special focus on the design of TRAP1 specific inhibitors. Although TRAP1 was extensively studied in the oncology field, its role in central nervous system cells, under physiological and pathological conditions, remains largely unknown. In this review, we will start by summarizing the biology of TRAP1, including its structure and related pathways. Thereafter, we will continue by debating the role of TRAP1 in the maintenance of redox homeostasis and protection against oxidative stress and apoptosis. The role of TRAP1 in neurodegenerative disorders will also be discussed. Finally, we will review the potential of TRAP1 inhibitors as neuroprotective drugs.

scholarly journals Heat Shock-Induced Dephosphorylation of Eukaryotic Elongation Factor 1BδL by Protein Phosphatase 1

2021 ◽  
Vol 7 ◽  
Author(s):  
Taku Kaitsuka ◽  
Kazuhito Tomizawa ◽  
Masayuki Matsushita
Keyword(s):  
Heat Shock ◽  
Protein Phosphatase ◽  
Elongation Factor ◽  
Protein Phosphatase 1 ◽  
Cyclin Dependent Kinase ◽  
Proteotoxic Stress ◽  
Eukaryotic Elongation Factor ◽  
Functional Regulation

Several variant proteins are produced from EEF1D, including two representative proteins produced via alternative splicing machinery. One protein is the canonical translation eukaryotic elongation factor eEF1Bδ1, and the other is the heat shock-responsive transcription factor eEF1BδL. eEF1Bδ1 is phosphorylated by cyclin-dependent kinase 1 (CDK1), but the machinery controlling eEF1BδL phosphorylation and dephosphorylation has not been clarified. In this study, we found that both proteins were dephosphorylated under heat shock and proteotoxic stress, and this dephosphorylation was inhibited by okadaic acid. Using proteins with mutations at putative phosphorylated residues, we revealed that eEF1Bδ1 and eEF1BδL are phosphorylated at S133 and S499, respectively, and these residues are both CDK1 phosphorylation sites. The eEF1BδL S499A mutant more strongly activated HSPA6 promoter-driven reporter than the wild-type protein and S499D mutant. Furthermore, protein phosphatase 1 (PP1) was co-immunoprecipitated with eEF1Bδ1 and eEF1BδL, and PP1 dephosphorylated both proteins in vitro. Thus, this study clarified the role of phosphorylation/dephosphorylation in the functional regulation of eEF1BδL during heat shock.

scholarly journals Caught in the middle: the role of Bag3 in disease

2009 ◽  
Vol 425 (1) ◽  
pp. e1-e3 ◽  
Author(s):  
Andrea K. McCollum ◽  
Giovanna Casagrande ◽  
Elise C. Kohn
Keyword(s):  
Heat Shock ◽  
Muscular Dystrophy ◽  
Heat Shock Protein ◽  
Heat Shock Protein 70 ◽  
Small Heat Shock Protein ◽  
Cag Repeats ◽  
Binding Partner ◽  
Biochemical Journal ◽  
Exon 1

Bag3 is a Bag family co-chaperone that regulates the ATPase activity of Hsp70 (heat-shock protein 70) chaperones. Recent studies have demonstrated that Bag3 can initiate macroautophagy in co-operation with small heat-shock protein HspB8. In this issue of the Biochemical Journal, Fuchs and co-workers have discovered the IPV motif in Bag3 that is necessary for binding to HspB8. The authors have also identified HspB6 as a new binding partner for Bag3 and characterized further the binding of both HspB8 and HspB6 in Bag3-mediated clearance of aggregated polyglutamine-containing protein Htt43Q (huntingtin exon 1 fragment with 43 CAG repeats). It is clear from recent identification of a Bag3 mutation that causes a form of muscular dystrophy that the full function of Bag3 in disease is not clear. We will apply the findings of Fuchs et al. in this issue to reconcile the phenotypes of Bag3 homologue knockouts with the emerging role of Bag3 in autophagy.

158. THE UNFOLDED PROTEIN RESPONSE MAY CONTRIBUTE TO GLUCOCORTICOID-INDUCED PLACENTAL GROWTH RESTRICTION IN THE RAT VIA INCREASED PLACENTAL EXPRESSION OF HEAT SHOCK PROTEIN 70

2010 ◽  
Vol 22 (9) ◽  
pp. 76
Author(s):  
P. J. Mark ◽  
J. L. Lewis ◽  
M. L. Jones ◽  
B. J. Waddell
Keyword(s):  
Heat Shock ◽  
Er Stress ◽  
Unfolded Protein Response ◽  
Separate Analysis ◽  
Heat Shock Factors ◽  
Hsp 70 ◽  
Unfolded Protein ◽  
The Unfolded Protein Response ◽  
Hsp 90 ◽  
Protein Response

Perturbations of normal endoplasmic reticulum (ER) physiology occur in a number of pathological conditions, including diabetes and preeclampsia. These pathologies are associated with elevated levels of inappropriately folded proteins and induction of ER stress. Accumulation of misfolded proteins induces the unfolded protein response which increases ER protein folding capacity and promotes ER-associated degradation of unfolded proteins. Glucocorticoids are essential for maturation of fetal organs, however excess exposure during pregnancy retards fetal and placental growth. Glucocorticoids also induce ER stress within macrophages, which reside within the placenta, and activate immune responses which can lead to oxidative stress and subsequent placental dysfunction. We hypothesised that excess glucocorticoid exposure would induce ER stress within the placenta and contribute to restriction of fetal and placental growth. This study compared placentas (n = 6/group) for control (Con) and dexamethasone-exposed pregnancies (Dex; 0.75 μg/mL drinking water from day 13 of gestation) at days 16 and 22 of gestation in the rat (term = 23 days). Placentas were dissected into junctional (JZ) and labyrinth (LZ) zones for separate analysis. Quantitative PCR was used to determine expression of mRNA for markers of ER stress, including heat shock factors (HSF-1 and HSF-2), heat shock proteins (HSP-70 and HSP-90) and C/EBP homologous protein (CHOP10). HSF-1 expression increased 2- to 4-fold from day 16 to 22 in both placental zones, but was not increased by glucocorticoids. Dex-exposure increased HSP-70 expression 2- to 3-fold in the LZ at both days of gestation, indicative of an ER stress response. Similar patterns for JZ expression of HSP-70 were observed. JZ expression of HSP-90 was also upregulated by Dex at day 22 but not day 16. CHOP10 was not induced by Dex-administration in either zone at either gestational time, which suggests that rather than activation of the ATF6/PERK pathway, the activation of ER stress is likely to be via XBP1 induction.

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