PubMed Central (PMC3 - NLM DTD)
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Archive of life sciences journal literature at the U.S. National Institutes of Health (NIH), developed and managed by NIH's National Center for Biotechnology Information (NCBI) in the National Library of Medicine (NLM).
Mostrando recursos 161 - 180 de 951
161.
Tomato heat stress protein Hsp16.1-CIII represents a member of a new class of nucleocytoplasmic small heat stress proteins in plants - Siddique, Masood; Port, Markus; Tripp, Joanna; Weber, Christian; Zielinski, Dirk; Calligaris, Raffaella; Winkelhaus, Sibylle; Scharf, Klaus-Dieter
We describe a new class of plant small heat stress proteins (sHsps) with dominant nuclear localization (Hsp17-CIII). The corresponding proteins in tomato, Arabidopsis, and rice are encoded by unique genes containing a short intron in the ?4-encoding region of the ?-crystallin domain (ACD). The strong nuclear localization results from a cluster of basic amino acid residues in the loop between ?5 and ?6 of the ACD. Using yeast 2-hybrid tests, analyses of native complexes of the sHsps, and immunofluorescence data, we demonstrate that, in contrast to earlier observations (Kirschner et al 2000), proteins of the sHsp classes CI, CII, and...
162.
Spatial analysis of cell death and Hsp70 induction in brain, thymus, and bone marrow of the hyperthermic rat - Belay, Hiwote T.; Brown, Ian R.
Heat shock response and programmed cell death are cellular reactions to stressful stimuli. Previous studies have not correlated these responses in vivo at the spatial level in mammalian tissues. This study uses a dual procedure involving immunocytochemistry for Hsp70 localization and the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-endlabeling (TUNEL) assay for cell death to correlate the pattern of stress-inducible Hsp70 and cell death at the cellular level. After whole-body hyperthermia in the rat, an increase in Hsp70-positive cells and TUNEL-positive cells was noted in brain, thymus, and bone marrow. However, 2 populations of cells were apparent in the tissues examined,...
163.
The messenger and the message: gp96 (GRP94)-peptide interactions in cellular immunity - Nicchitta, Christopher V.; Carrick, Deanna M.; Baker-LePain, Julie C.
Vaccination of mice with tumor-derived stress proteins, such as Hsp70 and gp96 (GRP94), can elicit antitumor immune responses, yielding a marked suppression of tumor growth and metastasis. The molecular basis for this response is proposed to reflect a peptide-binding function for these proteins. In this view, stress proteins bind the antigenic peptide repertoire of their parent cell, and when provided to the immune system, tumor-derived stress protein peptide complexes are processed by antigen-presenting cells (APCs) to yield the subsequent activation of tumor-directed cytotoxic T lymphocyte activity. This model predicts that stress proteins, whose primary intracellular function concerns the proper folding...
164.
Cloning and molecular characterization of heat shock cognate 70 from tiger shrimp (Penaeus monodon) - Lo, Wan-Yu; Liu, Kuan-Fu; Liao, I-Chiu; Song, Yen-Ling
We cloned the complementary deoxyribonucleic acid (cDNA) of the heat shock cognate 70 (hsc70) gene of tiger shrimp (Penaeus monodon). It was 2207 bp long and included a 1959-bp coding region, a 40-bp flanking region at the 5? end, and a 208-bp flanking region at the 3? end. The deduced, 652amino acid sequence had a molecular mass of 71?481 Da and an estimated isoelectric point (pI) of 5.2. Based on phylogenetic analysis, the gene is clustered with the hsc70 proteins of invertebrates and vertebrates. In native gel electrophoresis, recombinant P monodon hsc70 expressed in an Escherichia coli system is tightly...
165.
Folate supplementation reduces serum Hsp70 levels in patients with type 2 diabetes - Hunter-Lavin, Claire; Hudson, Peter R.; Mukherjee, Sagarika; Davies, Gareth K.; Williams, Clive P.; Harvey, John N.; Child, David F.; Williams, John H.H.
Type 2 diabetes patients are subject to oxidative stress as a result of hyperglycemia. The aim of this study was to determine whether administration of the antioxidant folic acid, previously shown to reduce homocysteine levels, would reduce circulating levels of Hsp70 while improving the condition of type 2 diabetes patients with microalbuminuria. Plasma homocysteine fell from pretreatment values of 12.9 to 10.3 ?M (P < 0.0001). The urine albumin-creatinine ratio fell from 12.4 to 10.4 mg/mM (P = 0.38). Pretreatment Hsp70 levels were higher in patients not taking insulin (5.32 ng/mL) compared with those on insulin (2.44 ng/mL) (P =...
166.
Characterization of goldfish heat shock protein30 induced upon severe heat shock in cultured cells - Kondo, Hidehiro; Harano, Ryohei; Nakaya, Misako; Watabe, Shugo
Temperature-dependent changes of growth rate and protein components were investigated for primary cultured cells derived from goldfish caudal fin. When the culture temperature was shifted from 20°C to 35°C and 40°C, the growth rate was increased at 35°C as compared with that at 20°C, but no cell growth was observed at 40°C. The differential scanning calorimetry demonstrated the onset of the endothermic reaction for goldfish cellular components at 40°C. Therefore, the temperature shift to 40°C was found to be of severe heat shock for goldfish cultured cells. Sodium dodecyl sulfatepolyacrylamide gel electrophoresis analysis revealed that, although expression of 70-kDa components...
167.
Investigating the protein-protein interactions of the yeast Hsp90 chaperone system by two-hybrid analysis: potential uses and limitations of this approach - Millson, Stefan H.; Truman, Andrew W.; Wolfram, Francis; King, Victoria; Panaretou, Barry; Prodromou, Chrisostomos; Pearl, Laurence H.; Piper, Peter W.
The Hsp90 chaperone cycle involves sequential assembly of different Hsp90-containing multiprotein complexes, the accessory proteins (cochaperones) that are associated with these complexes being exchanged as the cycle proceeds from its early to its late stages. To gain insight as to whether the 2-hybrid system could be used to probe the interactions of this Hsp90 system, yeast transformants were constructed that express the Gal4p deoxyribonucleic acidbinding domain (BD) fused to the 2 Hsp90 isoforms and the various Hsp90 system cochaperones of yeast. These bait fusions were then introduced by mating into other transformants expressing nearly all the 6000 proteins of yeast...
168.
Heat shock treatment protects osmotic stressinduced dysfunction of the blood-brain barrier through preservation of tight junction proteins - Lu, Tzong-Shi; Chen, Hsiang-Wen; Huang, Maw-Hsiung; Wang, Shu-Jung; Yang, Rei-Cheng
The blood-brain barrier (BBB) is a specialized structure in the central nervous system (CNS), which participates in maintenance of a state of cerebrospinal fluid homeostasis. The endothelial cells of the cerebral capillaries and the tight junctions between them form the basis of the BBB. Research has shown that destruction of the BBB is associated with diseases of the CNS. However, there is little research on how the BBB might be protected. In this study, we used a high osmotic solution (1.6 M d-mannitol) to open the BBB of rats and Evans blue dye as a macromolecular marker. The effect of...
169.
Paeoniflorin, a novel heat shock proteininducing compound - Yan, Dai; Saito, Kiyoto; Ohmi, Yuri; Fujie, Noriyo; Ohtsuka, Kenzo
Heat shock proteins (HSPs) are induced by various physical, chemical, and biological stresses. HSPs are known to function as molecular chaperones, and they not only regulate various processes of protein biogenesis but also function as lifeguards against proteotoxic stresses. Because it is very useful to discover nontoxic chaperone-inducing compounds, we searched for them in herbal medicines. Some herbal medicines had positive effects on the induction of HSPs (Hsp70, Hsp40, and Hsp27) in cultured mammalian cells. We next examined 2 major constituents of these herbal medicines, glycyrrhizin and paeoniflorin, with previously defined chemical structures. Glycyrrhizin had an enhancing effect on the...
170.
Glucose ingestion attenuates the exercise-induced increase in circulating heat shock protein 72 and heat shock protein 60 in humans - Febbraio, Mark A.; Mesa, Jose L.; Chung, Jason; Steensberg, Adam; Keller, Charlotte; Nielsen, Henning B.; Krustrup, Peter; Ott, Peter; Secher, Niels H.; Pedersen, Bente K.
Heat shock protein (Hsp) 72 is a cytosolic stress protein that is highly inducible by several factors including exercise. Hsp60 is primarily mitochondrial in cellular location, plays a key role in the intracellular protein translocation and cytoprotection, is increased in skeletal muscle by exercise, and is found in the peripheral circulation of healthy humans. Glucose deprivation increases Hsp72 in cultured cells, whereas reduced glycogen availability elevates Hsp72 in contracting human skeletal muscle. To determine whether maintained blood glucose during exercise attenuates the exercise-induced increase in intramuscular and circulating Hsp72 and Hsp60, 6 males performed 120 minutes of semirecumbent cycling at...
174.
Hsp70 mutant proteins modulate additional apoptotic pathways and improve cell survival - Ran, Ruiqiong; Zhou, Guoping; Lu, Aigang; Zhang, Lu; Tang, Yang; Rigby, Alan C.; Sharp, Frank R.
Although wild-type Hsp70 (Hsp70WT) inhibits procaspase-3 processing by preventing apoptosome formation, Hsp70WT does not block active caspase-3. Because all caspase-3 inhibitors bear canonical DXXD caspase-3 recognition motifs, we determined whether mutated Hsp70s with caspase-binding motifs act as direct caspase-3 inhibitors. Based on Hsp70 molecular modeling, the DNQP, DEVQ, and EEVD regions localized on the surface of Hsp70WT were chosen, allowing us to design mutants while trying to avoid disrupting the global fold of the molecule and losing the possibility of protein-protein interactions. We replaced DNQP with DQMD, and DEVQ and EEVD with DEVD residues that should be optimal substrates for...
175.
Intronic hormone response elements mediate regulation of FKBP5 by progestins and glucocorticoids - Hubler, Tina R.; Scammell, Jonathan G.
Expression of FKBP51, a large molecular weight immunophilin, is strongly enhanced by glucocorticoids, progestins, and androgens. However, the activity of a 3.4-kb fragment of the FKBP51 gene (FKBP5) promoter was only weakly increased by progestin and we show here that it is unresponsive to glucocorticoids and androgens. The entire FKBP5 was scanned for consensus hormone response elements (HREs) using MatInspector. We found that 2 regions of intron E, which are conserved in rat and mouse FKBP5, contain HRE-like sequences with high match scores. Deoxyribonucleic acid fragments (approximately 1 kb in length) containing these regions were amplified and tested in reporter...
176.
Localization and function in endoplasmic reticulum stress tolerance of ERdj3, a new member of Hsp40 family protein - Nakanishi, Katsuya; Kamiguchi, Kenjiro; Torigoe, Toshihiko; Nabeta, Chika; Hirohashi, Yoshihiko; Asanuma, Hiroko; Tobioka, Hirotoshi; Koge, Norie; Harada, Oi; Tamura, Yasuaki; Nagano, Hideki; Yano, Shoki; Chiba, Susumu; Matsumoto, Hiroyuki; Sato, Noriyuki
Heat shock protein 40 (Hsp40) family proteins are known to bind to Hsp70 through their J-domain and regulate the function of Hsp70 by stimulating its adenosine triphosphatase activity. In the endoplasmic reticulum (ER), there are 5 Hsp40 family proteins known so far, 3 of which were recently identified. In this report, one of the novel Hsp40 cochaperones, ERdj3, was characterized in terms of its subcellular localization, stress response, and stress tolerance of cells. By using ERdj3-specific polyclonal antibody, endogenous ERdj3 protein was shown to reside in the ER as gene transfermediated exogenous ERdj3. Analysis of the expression level of endogenous...
177.
Downstream caspases are novel targets for the antiapoptotic activity of the molecular chaperone Hsp70 - Komarova, Elena Yu.; Afanasyeva, Elena A.; Bulatova, Marina M.; Cheetham, Michael E.; Margulis, Boris A.; Guzhova, Irina V.
The response of cancer cells to apoptosis-inducing agents can be characterized by 2 opposing factors, the proapoptotic caspase cascade and the antiapoptotic stress protein Hsp70. We show here that these factors interact in U-937 leukemia cells induced to apoptosis with anticancer drugs, etoposide and adriamycin (ADR). The protective effect of Hsp70 was verified using 2 approaches: mild heat stress and transfection-mediated overexpression of the Hsp70 gene. The increase in Hsp70 levels attained by these 2 methods was found to postpone caspase activation for 1218 hours. An in vitro assay was developed using mouse myeloma NS0/1 cells, which lack the expression...
178.
Exercise induces the release of heat shock protein 72 from the human brain in vivo - Lancaster, G. I.; Møller, K.; Nielsen, B.; Secher, N. H.; Febbraio, M. A.; Nybo, L.
The present study tested the hypothesis that in response to physical stress the human brain has the capacity to release heat shock protein 72 (Hsp72) in vivo. Therefore, 6 humans (males) cycled for 180 minutes at 60% of their maximal oxygen uptake, and the cerebral Hsp72 response was determined on the basis of the internal jugular venous to arterial difference and global cerebral blood flow. At rest, there was a net balance of Hsp72 across the brain, but after 180 minutes of exercise, we were able to detect the release of Hsp72 from the brain (335 ± 182 ng/min). However,...
179.
Mitochondrial mechanism of heat stress-induced injury in rat cardiomyocyte - Qian, Lingjia; Song, Xueli; Ren, Huirong; Gong, Jingbo; Cheng, Suqi
Heat stress results in cardiac dysfunction and even cardiac failure. To elucidate the cellular and molecular mechanism of cardiomyocyte injury induced by heat stress, the changes of structure and function in cardiac mitochondria of heat-exposed Wistar rats and its role in cardiomyocyte injury were investigated. Heat stress induced apoptosis and necrosis of cardiomyocytes in a time- and dose-dependent fashion. In the mitochondria of heat-stressed cardiomyocytes, the respiratory control rate and oxidative phosphorylation efficiency (P:O) were decreased gradually with the rise of rectal temperature. The Ca2+-adenosine triphosphatase activity and Ca2+ content were also reduced. Exposing isolated mitochondria to the heat stress...
180.
The heat shock protein HSP70 and heat shock cognate protein HSC70 contribute to antimony tolerance in the protozoan parasite Leishmania - Brochu, Christian; Haimeur, Anass; Ouellette, Marc
Antimony-containing drugs are still the drugs of choice in the treatment of infections caused by the parasite Leishmania. Resistance to antimony is now common in some parts of the world, and several mechanisms of resistance have been described. By transfecting cosmid banks and selecting with potassium antimonyl tartrate (SbIII), we have isolated a cosmid associated with resistance. This cosmid contains 2 copies of the heat shock protein 70 (HSP70) and 1 copy of the heat shock cognate protein 70 (HSC70). Several data linked HSP70 to antimony response and resistance. First, several Leishmania species, both as promastigotes and amastigotes, increased the...
161.
