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Girard PM, Peynot N, Lelièvre JM. Differential correlations between changes to glutathione redox state, protein ubiquitination, and stress-inducible HSPA chaperone expression after different types of oxidative stress. Cell Stress Chaperones 2018; 23:985-1002. [PMID: 29754332 PMCID: PMC6111089 DOI: 10.1007/s12192-018-0909-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 04/04/2018] [Accepted: 05/01/2018] [Indexed: 01/03/2023] Open
Abstract
In primary bovine fibroblasts with an hspa1b/luciferase transgene, we examined the intensity of heat-shock response (HSR) following four types of oxidative stress or heat stress (HS), and its putative relationship with changes to different cell parameters, including reactive oxygen species (ROS), the redox status of the key molecules glutathione (GSH), NADP(H) NAD(H), and the post-translational protein modifications carbonylation, S-glutathionylation, and ubiquitination. We determined the sub-lethal condition generating the maximal luciferase activity and inducible HSPA protein level for treatments with hydrogen peroxide (H2O2), UVA-induced oxygen photo-activation, the superoxide-generating agent menadione (MN), and diamide (DA), an electrophilic and sulfhydryl reagent. The level of HSR induced by oxidative stress was the highest after DA and MN, followed by UVA and H2O2 treatments, and was not correlated to the level of ROS production nor to the extent of protein S-glutathionylation or carbonylation observed immediately after stress. We found a correlation following oxidative treatments between HSR and the level of GSH/GSSG immediately after stress, and the increase in protein ubiquitination during the recovery period. Conversely, HS treatment, which led to the highest HSR level, did not generate ROS nor modified or depended on GSH redox state. Furthermore, the level of protein ubiquitination was maximum immediately after HS and lower than after MN and DA treatments thereafter. In these cells, heat-induced HSR was therefore clearly different from oxidative stress-induced HSR, in which conversely early redox changes of the major cellular thiol predicted the level of HSR and polyubiquinated proteins.
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Affiliation(s)
- Pierre-Marie Girard
- Institut Curie, PSL Research University, CNRS UMR3347, INSERM U1021, 91405, Orsay, France
- Université Paris-Sud, Université Paris-Saclay, Rue Georges Clémenceau, 91405, Orsay, France
| | - Nathalie Peynot
- UMR BDR, INRA, ENVA, Université Paris Saclay, 78350, Jouy-en-Josas, France
| | - Jean-Marc Lelièvre
- UMR BDR, INRA, ENVA, Université Paris Saclay, 78350, Jouy-en-Josas, France.
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France.
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Ruprecht B, Zecha J, Heinzlmeir S, Médard G, Lemeer S, Kuster B. Evaluation of Kinase Activity Profiling Using Chemical Proteomics. ACS Chem Biol 2015; 10:2743-52. [PMID: 26378887 DOI: 10.1021/acschembio.5b00616] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Protein kinases are important mediators of intracellular signaling and are reversibly activated by phosphorylation. Immobilized kinase inhibitors can be used to enrich these often low-abundance proteins, to identify targets of kinase inhibitors, or to probe their selectivity. It has been suggested that the binding of kinases to affinity beads reflects a kinase's activation status, a concept that is under considerable debate. To assess the merits of the idea, we performed a series of experiments including quantitative phosphoproteomics and purification of kinases by single or mixed affinity matrices from signaling activated or resting cancer cells. The data show that mixed affinity beads largely bind kinases independent of their activation status, and experiments using individual immobilized kinase inhibitors show mixed results in terms of preference for binding the active or inactive conformation. Taken together, activity- or conformation-dependent binding to such affinity resins depends (i) on the kinase, (ii) on the affinity probe, and (iii) on the activation status of the lysate or cell. As a result, great caution should be exercised when inferring kinase activity from such binding data. The results also suggest that assaying kinase activity using binding data is restricted to a limited number of well-chosen cases.
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Affiliation(s)
- Benjamin Ruprecht
- Chair
of Proteomics and Bioanalytics, Technische Universität München, Emil-Erlenemeyer-Forum 5, 85354 Freising, Germany
- Center for Protein Science Munich (CIPSM), 85354 Freising, Germany
| | - Jana Zecha
- Chair
of Proteomics and Bioanalytics, Technische Universität München, Emil-Erlenemeyer-Forum 5, 85354 Freising, Germany
- German Cancer Consortium (DKTK), 69120 Heidelberg, Germany
- German Cancer Research Center (DKFZ), 69121 Heidelberg, Germany
| | - Stephanie Heinzlmeir
- Chair
of Proteomics and Bioanalytics, Technische Universität München, Emil-Erlenemeyer-Forum 5, 85354 Freising, Germany
- German Cancer Consortium (DKTK), 69120 Heidelberg, Germany
- German Cancer Research Center (DKFZ), 69121 Heidelberg, Germany
| | - Guillaume Médard
- Chair
of Proteomics and Bioanalytics, Technische Universität München, Emil-Erlenemeyer-Forum 5, 85354 Freising, Germany
| | - Simone Lemeer
- Chair
of Proteomics and Bioanalytics, Technische Universität München, Emil-Erlenemeyer-Forum 5, 85354 Freising, Germany
- Center for Protein Science Munich (CIPSM), 85354 Freising, Germany
| | - Bernhard Kuster
- Chair
of Proteomics and Bioanalytics, Technische Universität München, Emil-Erlenemeyer-Forum 5, 85354 Freising, Germany
- Center for Protein Science Munich (CIPSM), 85354 Freising, Germany
- German Cancer Consortium (DKTK), 69120 Heidelberg, Germany
- German Cancer Research Center (DKFZ), 69121 Heidelberg, Germany
- Bavarian
Biomolecular Mass Spectrometry Center, Technische Universität München, 85354 Freising, Germany
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Caruso JA, Stemmer PM, Dombkowski A, Caruthers NJ, Gill R, Rosenspire AJ. A systems toxicology approach identifies Lyn as a key signaling phosphoprotein modulated by mercury in a B lymphocyte cell model. Toxicol Appl Pharmacol 2014; 276:47-54. [PMID: 24440445 DOI: 10.1016/j.taap.2014.01.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 12/24/2013] [Accepted: 01/04/2014] [Indexed: 01/10/2023]
Abstract
Network and protein-protein interaction analyses of proteins undergoing Hg²⁺-induced phosphorylation and dephosphorylation in Hg²⁺-intoxicated mouse WEHI-231 B cells identified Lyn as the most interconnected node. Lyn is a Src family protein tyrosine kinase known to be intimately involved in the B cell receptor (BCR) signaling pathway. Under normal signaling conditions the tyrosine kinase activity of Lyn is controlled by phosphorylation, primarily of two well known canonical regulatory tyrosine sites, Y-397 and Y-508. However, Lyn has several tyrosine residues that have not yet been determined to play a major role under normal signaling conditions, but are potentially important sites for phosphorylation following mercury exposure. In order to determine how Hg²⁺ exposure modulates the phosphorylation of additional residues in Lyn, a targeted MS assay was developed. Initial mass spectrometric surveys of purified Lyn identified 7 phosphorylated tyrosine residues. A quantitative assay was developed from these results using the multiple reaction monitoring (MRM) strategy. WEHI-231 cells were treated with Hg²⁺, pervanadate (a phosphatase inhibitor), or anti-Ig antibody (to stimulate the BCR). Results from these studies showed that the phosphoproteomic profile of Lyn after exposure of the WEHI-231 cells to a low concentration of Hg²⁺ closely resembled that of anti-Ig antibody stimulation, whereas exposure to higher concentrations of Hg²⁺ led to increases in the phosphorylation of Y-193/Y-194, Y-501 and Y-508 residues. These data indicate that mercury can disrupt a key regulatory signal transduction pathway in B cells and point to phospho-Lyn as a potential biomarker for mercury exposure.
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Affiliation(s)
- Joseph A Caruso
- Institute of Environmental Health Sciences, Wayne State University, Detroit, MI, USA
| | - Paul M Stemmer
- Institute of Environmental Health Sciences, Wayne State University, Detroit, MI, USA
| | - Alan Dombkowski
- Department of Pediatrics, Wayne State University, Detroit, MI, USA
| | - Nicholas J Caruthers
- Institute of Environmental Health Sciences, Wayne State University, Detroit, MI, USA
| | - Randall Gill
- Department of Immunology and Microbiology, Wayne State University, Detroit, MI, USA
| | - Allen J Rosenspire
- Department of Immunology and Microbiology, Wayne State University, Detroit, MI, USA.
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Byun K, Kim TK, Oh J, Bayarsaikhan E, Kim D, Lee MY, Pack CG, Hwang D, Lee B. Heat shock instructs hESCs to exit from the self-renewal program through negative regulation of OCT4 by SAPK/JNK and HSF1 pathway. Stem Cell Res 2013; 11:1323-34. [PMID: 24090933 DOI: 10.1016/j.scr.2013.08.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2012] [Revised: 08/29/2013] [Accepted: 08/30/2013] [Indexed: 10/26/2022] Open
Abstract
Environmental factors affect self-renewal of stem cells by modulating the components of self-renewal networks. Heat shock, an environmental factor, induces heat shock factors (HSFs), which up-regulate stress response-related genes. However, the link of heat shock to self-renewal of stem cells has not been elucidated yet. Here, we present the direct link of heat shock to a core stem cell regulator, OCT4, in the self-renewal network through SAPK/JNK and HSF1 pathway. We first showed that heat shock initiated differentiation of human embryonic stem cells (hESCs). Gene expression analysis revealed that heat shock increased the expression of many genes involved in cellular processes related to differentiation of stem cells. We then examined the effects of HSFs induced by heat shock on core self-renewal factors. Among HSFs, heat shock induced mainly HSF1 in hESCs. The HSF1 repressed the expression of OCT4, leading to the differentiation of hESCs and the above differentiation-related gene expression change. We further examined the effects of the upstream MAP (mitogen-activated protein) kinases of HSF1 on the repression of OCT4 expression by HSF1. Among the MAP kinases, SAPK/JNK controlled predominantly the repression of the OCT4 expression by HSF1. The direct link of heat shock to the core self-renewal regulator through SAPK/JNK and HSF1 provides a fundamental basis for understanding the effect of heat and other stresses involving activation of HSF1 on the self-renewal program and further controlling differentiation of hESCs in a broad spectrum of stem cell applications using these stresses.
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Affiliation(s)
- Kyunghee Byun
- Center for Genomics and Proteomics & Stem Cell Core Facility, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon 406-840, Republic of Korea; Department of Anatomy and Cell Biology, Gachon University Medical School, Incheon 406-840, Republic of Korea
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Shaposhnikov AV, Kryndushkin AS, Nikolenko YV, Panov VV, Nabirochkina EN, Lebedeva LA, Shidlovskii YV. Activation of JAK/STAT signaling pathway in Drosophila melanogaster S2 cell culture. Mol Biol 2013. [DOI: 10.1134/s0026893313030138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Abstract
The heat shock protein (HSP) molecular chaperones are the primary cellular defense against damage to the proteome, initiating refolding of denatured proteins and regulating degradation after severe protein damage. Many neurodegenerative disorders involve aberrant protein folding and protein damage, which accumulates in an age-dependent manner. Ageing is associated with the decrease in activity of the heat shock transcription factors (HSF) that regulate HSP gene transcription. Neuronal cells seem particularly vulnerable in this sense as HSF activity and HSP expression are relatively weak in such cells and motor neurons appear to require input of HSP secreted from adjacent glial cells to maintain adequate molecular chaperone levels. It may be significant that motor neurons have been shown to be the sensitive cells in the ageing of Drosophila and C. elegans and that these organisms may acquire extended lifespans with over-expression of small heat shock proteins and HSF1. HSF1 transcriptional activity has been discussed in neuronal cells, concentrating on the regulation and activity of HSF1 and HSF2 and their role in HSP expression, during neurodegenerative diseases and as mediators of cell survival.
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Affiliation(s)
- J Tonkiss
- Center for Behavioral Development, Boston University School of Medicine, Boston, MA, USA
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A S, JC M, Y G, F C, JP S, A EF. Green Tea Drinking Reduces the Effects of Vanadium Poisoning in Rat Kidney. FOOD SCIENCE AND TECHNOLOGY RESEARCH 2009. [DOI: 10.3136/fstr.15.413] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Gong Z, Yang J, Yang M, Wang F, Wei Q, Tanguay RM, Wu T. Benzo(a)pyrene inhibits expression of inducible heat shock protein 70 in vascular endothelial cells. Toxicol Lett 2006; 166:229-36. [PMID: 16962263 DOI: 10.1016/j.toxlet.2006.07.307] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2006] [Revised: 07/15/2006] [Accepted: 07/17/2006] [Indexed: 11/28/2022]
Abstract
Benzo(a)pyrene (BaP), a ubiquitous environmental pollutant known to cause many diseases including atherosclerosis, induces a dose-dependent reduction in the levels of the inducible Hsp70. To explore the mechanism underlying the reduction of Hsp70, we measured the levels of Hsp70, cytoplasmic and nuclear heat shock factor 1 (HSF1) in porcine aortic endothelial cells using Western blot, and then further characterized the binding ability of HSF1 and heat shock element (HSE) by electrophoretic mobility shift assay. We found that when porcine aortic endothelial cells were treated by 0.1-10 microM of BaP for 24 h, there was a significant reduction of Hsp70, cytoplasmic and nuclear HSF1 and the binding rate of HSF1 and HSE at 5, 10 microM of BaP but less effective at lower concentrations. The effect of BaP on the Hsp70 expression level was markedly attenuated by co-treatment with phorbol 12-myristate 13-acetate (PMA), an activator of protein kinase C (PKC). Staurosporine (STP), an inhibitor of PKC, blocked the effect of PMA treatment in combination with BaP. These results suggest that BaP might inhibit Hsp70 levels by reducing the expression of HSF1 and decreasing binding of HSF1 and HSE via PKC-dependent signaling pathways that might be involved in the regulation of Hsp70 gene expression under BaP.
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Affiliation(s)
- Z Gong
- Department of Occupational and Environmental Health and Ministry of Education Key Lab for Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PR China
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Soussi A, Gaubin Y, Beau B, Murat JC, Soleilhavoup JP, Croute F, El Feki A. Stress proteins (Hsp72/73, Grp94) expression pattern in rat organs following metavanadate administration. Effect of green tea drinking. Food Chem Toxicol 2006; 44:1031-7. [PMID: 16497423 DOI: 10.1016/j.fct.2005.12.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2005] [Revised: 12/21/2005] [Accepted: 12/22/2005] [Indexed: 11/27/2022]
Abstract
Expression pattern of heat shock proteins (Hsp) 72/73 and glucose regulated protein (Grp) 94 was studied in liver, kidney and testis of rats injected with sublethal doses of ammonium metavanadate (5 mg/kg/day). In addition, some batches of animals were given green tea decoction, known to be rich in anti-oxidative compounds, as sole beverage in order to evaluate its protective properties. In control animals, the stress proteins expression was found to be organ-dependent: anti-Grp94 antibody revealed two bands at 96 and 98 kDa in kidney and liver whereas the 98 kDa band only was found in testis; anti-Hsp72/73 antibody revealed that the constitutive Hsp73 was present in all organs whereas the inducible Hsp72 was only present in kidney and testis. In kidney of vanadium-treated rats, Hsp73 was over-expressed by about 50% whereas Hsp72 was down-regulated by 50-80%. No such effects were observed in liver and testis. In liver and kidney of vanadium-treated rats, Grp94 was over-expressed by 50% and 150% respectively whereas no change was found in testis. In rats given green tea as sole beverage, the 96 kDa protein expression level in liver was reduced both in controls and in vanadium-treated animals. However, green tea drinking failed to prevent the vanadium-induced Hsp72 under-expression in kidney of vanadium-treated rats.
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Affiliation(s)
- A Soussi
- Laboratoire d'Ecophysiologie Animale, Faculté des Sciences de Sfax, 3018 Sfax, Tunisia
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Tao GZ, Zhou Q, Strnad P, Salemi MR, Lee YM, Omary MB. Human Ran Cysteine 112 Oxidation by Pervanadate Regulates Its Binding to Keratins. J Biol Chem 2005; 280:12162-7. [PMID: 15691838 DOI: 10.1074/jbc.m412505200] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We used a proteomic approach to identify proteins that associate with keratins 8 or 18 (K8/K18) in a pervanadate-dependent manner. Pervanadate triggers Ran-K8/K18 binding and a gel-migration-shift of Ran from 25 to 27 kDa, which does not occur upon exposure to H2O2 or vanadate or if pervanadate is excluded during cell solubilization. Generation of 27-kDa Ran is not related to hyperphosphorylation, is heat-insensitive, but occurs upon conversion of Ran cysteines to cysteic acid. The pervanadate-mediated Ran cysteine --> cysteic acid oxidation and its related gel migration shift affects other proteins including actin. Mutation of the three Ran cysteines (Cys-85, -112, and -120) showed that Ran Cys-112 oxidation generates 27-kDa Ran and accounts for its keratin binding. Proteasome inhibition accentuates Ran-keratin binding after cell exposure to pervanadate. Therefore, cell-free exposure to pervanadate causes cysteine to cysteic acid oxidation of Ran and several other proteins and Ran-K8/K18 association. In cells, stabilization of oxidized Ran by proteasome inhibition promotes Ran-keratin interaction. Keratin sequestration of oxidized Ran may provide a back-up protective mechanism in some cases of oxidative injury.
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Affiliation(s)
- Guo-Zhong Tao
- Palo Alto Veterans Affairs Medical Center, Palo Alto, California 94304, USA.
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Hur EH, Hur W, Choi JY, Kim IK, Kim HY, Yoon SK, Rhim H. Functional identification of the pro-apoptotic effector domain in human Sox4. Biochem Biophys Res Commun 2004; 325:59-67. [PMID: 15522200 DOI: 10.1016/j.bbrc.2004.09.215] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2004] [Indexed: 11/22/2022]
Abstract
Recent studies provide evidence that Sox4 is involved in regulating apoptosis as well as tumorigenesis of various human cancers; however, its role in the apoptotic machinery is not fully understood. Here we describe that the central domain containing glycine-rich region in Sox4, named CD, is a pivotal pro-apoptotic domain to induce apoptotic cell death. Deletion of the DNA-binding domain or trans-activation domain in Sox4 did not significantly affect pro-apoptotic activity, whereas transient transfection of the high mobility group box or the serine-rich region abrogated the apoptotic activity. Moreover, overexpression of the CD construct (aa 166-342) revealed the apoptotic activity comparable to that of wild-type Sox4, approximately 60% of cell death. Our data suggest that the apoptotic activity of Sox4 can be dissociated from its transcriptional trans-activation and is mediated through its CD.
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Affiliation(s)
- Eun-Hye Hur
- Research Institute of Molecular Genetics, Catholic Research Institutes of Medical Sciences, College of Medicine, The Catholic University of Korea, Seoul 137-701, Republic of Korea
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Sivák M, Mad’arová M, Tatiersky J, Marek J. First (Peroxo)vanadium(V) Complex with Heteroligand Formed in Reaction System − Synthesis, Structure and Reactivity of K[VO(O2)(omeida)]·H2O {omeida = N-[2-(2-oxomorpholine-4-yl)ethyl]iminodiacetato(2−)}. Eur J Inorg Chem 2003. [DOI: 10.1002/ejic.200200380] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Abstract
Fertilization involves the activation of Src-family protein kinases which play a role at multiple stages of the egg activation process. The objective of the present study was to determine the mechanism by which one of these kinases, the Fyn kinase, is activated in response to fertilization of the zebrafish egg. Inhibitor studies demonstrated that many aspects of egg activation, including Fyn activation, require phosphotyrosyl phosphatase activity. A phosphotyrosyl phosphatase was found to be tightly associated with Fyn kinase and this interaction was mapped to the SH2 domain of Fyn. Coimmunoprecipitation studies identified rPTPalpha as a phosphatase that is complexed with Fyn in the egg, raising the possibility that rPTPalpha is part of the regulatory mechanism responsible for activating Fyn at fertilization.
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Affiliation(s)
- Wenjun Wu
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas, 66160-7400, USA
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Park J, Liu AY. JNK phosphorylates the HSF1 transcriptional activation domain: role of JNK in the regulation of the heat shock response. J Cell Biochem 2002; 82:326-38. [PMID: 11527157 DOI: 10.1002/jcb.1163] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The role of c-Jun NH2-terminal kinase (JNK) signaling cascade in the stress-inducible phosphorylation of heat shock factor 1 (HSF1) was investigated using known agonists and antagonists of JNK. We showed that treatment of HeLa cells with MG132, a proteasome inhibitor and known INK activator, caused the transcriptional activation domain of HSF1 to be targeted and phosphorylated by JNK2 in vivo. Dose-response and time course studies of the effects of heat shock and anisomycin treatment showed a close correlation of the activation of JNK and hyperphosphorylation of HSF1. SB203580 inhibited INK at the 100 microM concentration and significantly reduced the amount of hyperphosphorylated HSF1 upon heat shock or anisomycin treatment. SB203580 and dominant-negative JNK suppress hsp70 promoter-driven reporter gene expression selectively at 45 degrees C but not at 42 degrees C heat stress, suggesting that JNK would be preferentially associated with the protective heat shock response against severe heat stress. The possibility that JNK-mediated phosphorylation of HSF1 may selectively stabilize the HSF1 protein and confers protection to cells under conditions of severe stress is discussed.
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Affiliation(s)
- J Park
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway 08854-8082, USA.
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Manalo DJ, Liu AY. Resolution, detection, and characterization of redox conformers of human HSF1. J Biol Chem 2001; 276:23554-61. [PMID: 11320084 DOI: 10.1074/jbc.m011300200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We describe here an experimental protocol for the resolution, detection, and quantitation of the reduced and oxidized conformers of human heat shock factor 1 (hHSF1) and report on the effects in vitro and in vivo of redox-active agents on the redox status, structure, and function of hHSF1. We showed that diamide, a reagent that promotes disulfide bond formation, caused a loss of immunorecognition of the monomeric hHSF1 protein in a standard Western blot detection procedure. Modification of the Western blot procedure to include dithiothreitol in the equilibration and transfer buffers after gel electrophoresis allowed for the detection of a compact, intramolecularly disulfide cross-linked oxidized hHSF1 (ox-hHSF1) in the diamide-treated sample. The effect of diamide was blocked by pretreatment with N-ethylmaleimide and was reversed by dithiothreitol added to the sample prior to gel electrophoresis. Incubation with nitrosoglutathione at 42 degrees C also promoted the conversion of HSF1 to ox-HSF1; at 25 degrees C, however, nitrosoglutathione was by itself without effect but blocked the formation of ox-hHSF1 in the presence of diamide. The disulfide cross-linked ox-hHSF1 was monomeric and resistant to the in vitro heat-induced trimerization and activation. The possibility that ox-HSF1 may occur in oxidatively stressed cells was evaluated. Treatment of HeLa cells with 2 mm l-buthionine sulfoximine promoted the formation of ox-HSF1 and blocked the heat-induced activation of HSF DNA binding activity. Our result suggests that hHSF1 may have integrated redox chemistry of cysteine sulfhydryl into its functional responses.
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Affiliation(s)
- D J Manalo
- Graduate Program in Cell and Developmental Biology and Department of Cell Biology and Neuroscience, Rutgers State University, Piscataway, New Jersey 08854-8082, USA
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