PubMed Central (PMC3 - NLM DTD)
(2,081,148 recursos)
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 181 - 200 de 951
181.
Attenuation of okadaic acidinduced hyperphosphorylation of cytoskeletal proteins by heat preconditioning and its possible underlying mechanisms - Xu, Ya Fei; Jie Zhang, Yong; Hong Zhang, Ai; Zhang, Qi; Wu, Tangchun; Wang, Jian-Zhi
An imbalanced phosphorylation system is recognized to be one of the main reasons for Alzheimer-like hyperphosphorylation of cytoskeletal proteins. However, little is known about the strategies rectifying the lesions caused by this disrupted phosphorylation. To search for the means to arrest Alzheimer-like damages and explore the underlying mechanisms, in this study we treated N2a/peuht40 cells with okadaic acid (OA), a specific inhibitor of protein phosphatase-2A (PP-2A) and PP-1, to mimic an Alzheimer-like phosphatase-deficient system and then used heat preconditioning (42°C for 1 hour) to induce the expression of inducible heat shock protein 70 (Hsp70) in the cells. We observed that...
182.
Molecular cloning and expression of two HSP70 genes in the prawn, Macrobrachium rosenbergii - Liu, Jun; Yang, Wei-Jun; Zhu, Xiao-Jing; Karouna-Renier, Natalie K.; Rao, Ranga K.
Two complementary deoxyribonucleic acid (cDNA) clones encoding 2 different 70-kDa heat shock proteins (HSPs) were isolated from the prawn Macrobrachium rosenbergii. The cDNA clones were 2448 and 2173 bp in length and contained 1950- and 1734-bp open reading frames (ORFs), respectively. The ORFs encoded 649 and 577amino acid polypeptides, which were named Mar-HSC70 and Mar-HSP70, respectively, according to the sequence identities with other known HSC70s and HSP70s and based on their inducibility in response to heat shock stress (at 35°C). Genomic DNA sequence analysis revealed no introns in either gene. The major structural differences between the 2 proteins were a...
183.
Tetratricopeptide repeat cochaperones in steroid receptor complexes - Smith, David F.
The molecular chaperone machinery contains multiple protein components that have 1 or more structural domains composed of tetratricopeptide repeat (TPR) motifs. Many other proteins of separate or unknown function also have TPR domains, so this motif is not exclusive to molecular chaperones. A general function of TPR domains is to bind other polypeptides, but this otherwise prosaic function has been exploited in an assortment of ways that link chaperones and other protein systems into cooperative networks. Among the best-characterized TPR proteins are several cochaperones that participate in assembly and regulation of steroid receptor complexes. Steroid receptors, members of the nuclear...
184.
On mechanisms that control heat shock transcription factor activity in metazoan cells - Voellmy, Richard
Heat shock factor Hsf in nonvertebrate animals and homologous heat shock factor Hsf1 in vertebrate animals are key transcriptional regulators of the stress protein response. Hsf/Hsf1 is constitutively present in cells but is, typically, only active during periods during which cells are experiencing a physical or chemical proteotoxic stress. It has become increasingly clear that regulation of Hsf/Hsf1 activity occurs at multiple levels: the oligomeric status of Hsf/Hsf1, its DNA-binding ability, posttranslational modification, transcriptional competence, nuclear/ subnuclear localization, as well as its interactions with regulatory cofactors or other transcription factors all appear to be carefully controlled. This review emphasizes work...
185.
Expression of cytoprotective proteins, heat shock protein 70and metallothioneins, in tissues ofOstrea edulis exposed to heat andheavy metals - Piano, Annamaria; Valbonesi, Paola; Fabbri, Elena
Heat shock proteins (Hsps) are constitutively expressed in cells and involved in protein folding, assembly, degradation, intracellular localization, etc, acting as molecular chaperones. However, their overexpression represents a ubiquitous molecular mechanism to cope with stress. Hsps are classified into families, and among them the Hsp70 family appears to be the most evolutionary preserved and distributed in animals. In this study, the expression of Hsp70 and the related messenger ribonucleic acid (mRNA) has been studied in Ostrea edulis after exposure to heat and heavy metals; moreover, levels of metallothioneins (MTs), another class of stress-induced proteins, have contemporaneously been assessed in the...
186.
Hsp72 is present in plasma from Holstein-Friesian dairy cattle, and the concentration level is repeatable across days and age classes - Nygaard Kristensen, Torsten; Løvendahl, Peter; Berg, Peer; Loeschcke, Volker
Although heat shock proteins (Hsps) are primarily considered as being intracellular, this study identified the presence of Hsp72 in plasma from female Holstein-Friesian dairy cattle. Plasma samples were collected from the same animals at different ages and on different days after calving and accordingly divided into 5 age classes. The age classes were calves less than 235 days of age, young heifers between 235 and 305 days of age, older heifers between 305 and 560 days of age, cows early in lactation, and cows later in lactation. For a subsample of animals within each age class, replicate plasma samples were...
187.
Stimulation of Fas agonistic antibodymediated apoptosis by heparin-like agents suppresses Hsp27 but not Bcl-2 protective activity - Manero, Florence; Ljubic-Thibal, Vesna; Moulin, Maryline; Goutagny, Nadège; Yvin, Jean-Claude; Arrigo, André-Patrick
We report that in Jurkat T cells or freshly isolated T lymphocytes, physiological concentrations of high molecular weight sulfated polysaccharides such as heparin, heparan sulfate, and dextran sulfate significantly increased the percentage of cell death induced by Fas IgM agonistic antibody. The phenomenon was caspase dependent and P53 independent and correlated with an increased accessibility of cell surface Fas receptors. We also observed that the Fas IgM agonistic antibodydependent formation of sodium dodecyl sulfate (SDS)resistant large structures containing Fas receptor was decreased in the presence of heparin-like agents. In contrast, the different agents had no effect when cell death was...
188.
Interaction of the Hsp90 cochaperone cyclophilin 40 with Hsc70 - Carrello, Amerigo; Allan, Rudi K.; Morgan, Sarah L.; Owen, Barbara A.L.; Mok, Danny; Ward, Bryan K.; Minchin, Rodney F.; Toft, David O.; Ratajczak, Thomas
The high-affinity ligand-binding form of unactivated steroid receptors exists as a multicomponent complex that includes heat shock protein (Hsp)90; one of the immunophilins cyclophilin 40 (CyP40), FKBP51, or FKBP52; and an additional p23 protein component. Assembly of this heterocomplex is mediated by Hsp70 in association with accessory chaperones Hsp40, Hip, and Hop. A conserved structural element incorporating a tetratricopeptide repeat (TPR) domain mediates the interaction of the immunophilins with Hsp90 by accommodating the C-terminal EEVD peptide of the chaperone through a network of electrostatic and hydrophobic interactions. TPR cochaperones recognize the EEVD structural motif common to both Hsp90 and Hsp70...
189.
Rapid, transient, and dose-dependent expression of Hsp70 messenger RNA in the rat brain after morphine treatment - Ammon-Treiber, Susanne; Grecksch, Gisela; Stumm, Ralf; Riechert, Uta; Tischmeyer, Helga; Reichenauer, Anke; Höllt, Volker
Induction of Hsp70 in the brain has been reported after intake of drugs of abuse like amphetamine and lysergic acid diethylamide. In this investigation, gene expression of Hsp70 and other heat shock genes in the rat brain was studied in response to morphine. Twenty milligrams per kilogram morphine intraperitoneally resulted in a marked induction of Hsp70 messenger RNA (mRNA) expression in the frontal cortex with a maximum increase of 13.2-fold after 2 hours. A moderate increase of Hsp27 mRNA expression (6.7-fold) could be observed after 4 hours, whereas mRNA expression of Hsp90 and of the constitutive Hsc70 did not exceed...
190.
Upregulation and intrarenal redistribution of heat shock proteins 90? and 90? by low-sodium diet in the rat - Ramírez, Victoria; Uribe, Norma; García-Torres, Romeo; Castro, Clementina; Rubio, Julieta; Gamba, Gerardo; Bobadilla, Norma A.
Two genes encoding isoforms heat shock protein (Hsp) 90? and Hsp90? constitute the Hsp90 subfamily. In addition to their role in regulating mineralocorticoid and glucocorticoid receptors, these proteins have been associated with nitric oxide production. However, little is known regarding Hsp90 isoform expression and regulation in kidney. In this study we characterized the expression and localization of Hsp90 isoforms and evaluated the influence of low-sodium intake on their expression and distribution in kidney by using reverse transcriptionpolymerase chain reaction, Western blot, and immunohistochemistry techniques. We found that Hsp90? and Hsp90? were expressed abundantly in both the renal cortex and the...
191.
Frequency-specific association of antibodies against heat shock proteins 60 and 70 with noise-induced hearing loss in Chinese workers - Yang, Miao; Zheng, Jianru; Yang, Qiaoling; Yao, Huiling; Chen, Yongwen; Tan, Hao; Jiang, Changzheng; Wang, Feng; He, Meian; Chen, Sheng; Wei, Qingyi; Tanguay, Robert M.; Wu, Tangchun
Noise exposure may result in production of auto-antibodies against heat shock proteins (Hsps), which might be of significance in the pathogenesis or prognosis (or both) of auto-immune ear diseases. However, it is not known whether these antibodies are associated with noise-induced hearing loss (NIHL) in workers exposed to noise in occupational settings. Using immunoblotting with human recombinant Hsps, audiological assessment, and multivariate logistic regression models, we investigated the presence of antibodies against Hsp60 and Hsp70 and hearing levels, and analyzed their associations with NIHL in 399 workers exposed to noise between 75 and 115 dB. Our findings showed that the...
192.
Identification of Xenopus heat shock transcription factor2: conserved role of sumoylation in regulating deoxyribonucleic acidbinding activity of heat shock transcription factor2 proteins - Hilgarth, Roland S.; Murphy, Lynea A.; O'Connor, Colleen M.; Clark, James A.; Park-Sarge, Ok-Kyong; Sarge, Kevin D.
Heat shock transcription factor (Hsf)1 and Hsf2 are members of the heat shock factor (HSF) protein family involved in heat shock protein (hsp) gene regulation, a regulation that is critical for the ability of cells to survive exposure to stress conditions. Although the role of Hsf1 in binding and activating transcription of hsp gene promoters in response to cell stress is well established, how Hsf2 enhances stress-induced hsp expression is not understood. To gain an insight into the critical conserved features of the regulation and function of Hsf2, we have identified and characterized the Hsf2 protein from Xenopus laevis. We...
194.
Transcriptional regulation and binding of heat shock factor 1 and heat shock factor 2 to 32 human heat shock genes during thermal stress and differentiation - Trinklein, Nathan D.; Chen, Will C.; Kingston, Robert E.; Myers, Richard M.
Transcription of mammalian heat shock genes can be regulated by heat shock factors (HSF) 1 and 2. Although it has been shown previously that these factors respond to distinct stimuli, a broad analysis of the induction and function of these factors in living cells has not been performed. In our study, we assayed binding of human HSF1 and HSF2 at the promoters of 32 genes identified through LocusLink as heat shock genes in response to elevated temperature and hemin-induced differentiation in human K562 erythroleukemic cells using the chromatin immunoprecipitation technique. We also measured the induced expression of these genes under...
195.
HSP27 regulates fibroblast adhesion, motility, and matrix contraction - Hirano, Sahoko; Shelden, Eric A.; Gilmont, Robert R.
Heat shock protein 27 (HSP27) modulates actin-dependent cell functions in several systems. We hypothesized that HSP27 modulates wound contraction. Stably transfected fibroblast cell lines that overexpress HSP27 (SS12) or underexpress HSP27 (AS10) were established, and cell behaviors related to wound contraction were examined. First, fibroblast-populated collagen lattice (FPCL) contraction was examined because it has been studied as a wound-healing model. In floating FPCL contraction assays, SS12 cells caused increased contraction, whereas AS10 cells caused reduced contraction. Because floating matrix contraction is thought to be mediated by the tractional force of the cells, cell behaviors related to tractional force were examined....
196.
The mitochondrial 60-kDa heat shock protein in marine invertebrates: biochemical purification and molecular characterization - Choresh, Omer; Loya, Yossi; Müller, Werner E.G.; Wiedenmann, Jörg; Azem, Abdussalam
Sessile marine invertebrates undergo constant direct exposure to the surrounding environmental conditions, including local and global environmental fluctuations that may lead to fatal protein damage. Induction of heat shock proteins (Hsps) constitutes an important defense mechanism that protects these organisms from deleterious stress conditions. In a previous study, we reported the immunological detection of a 60-kDa Hsp (Hsp60) in the sea anemone Anemonia viridis (formerly called Anemonia sulcata) and studied its expression under a variety of stress conditions. In the present study, we show that the sponge Tetilla sp. from tidal habitats with a highly variable temperature regime is characterized...
197.
Cooperation of heat shock protein 90 and p23 in aryl hydrocarbon receptor signaling - Cox, Marc B.; Miller, Charles A.
Aryl hydrocarbon receptor (AhR) is a transcription factor that is activated by the binding of xenobiotic and endogenous ligands. AhR interacts with heat shock protein (Hsp) 90 complexes and can be used as a functional substrate to detect chaperone-dependent processes. Yeast Hsp90 (hsp82) mutants that variably affected AhR signaling were identified using reporter gene assays. Some mutated alleles resided in the p23/adenosine triphosphate (ATP)binding pocket of Hsp90, so the relationship between the cochaperone Sba1 (yeast p23) and adenosine triphosphatase (ATPase) activity was investigated. Deletion of the p23 gene in the hsp82G170D mutant background had a greater effect on AhR signaling...
198.
Mild heat stress stimulates 20S proteasome and its 11S activator in human fibroblasts undergoing aging in vitro - Beedholm, Rasmus; Clark, Brian F.C.; Rattan, Suresh I.S.
Repeated mild heat shock (RMHS) has been shown to have several beneficial hormetic effects on human skin fibroblast undergoing aging in vitro. Because an age-related decline in proteasome activity is 1 of the reasons for the accumulation of abnormal proteins during aging, we have investigated the effects of RMHS on the 20S proteasome, which is the major proteolytic system involved in the removal of abnormal and oxidatively damaged proteins. Serially passaged human skin fibroblasts exposed to RMHS at 41°C for 60 minutes twice a week had increased 3 proteasomal activities by 40% to 95% in early- and midpassage cultures. RMHS-treated...
199.
Induction of molecular chaperones in carbon tetrachloridetreated rat liver: implications in protection against liver damage - Lee, Kwang-Jong; Terada, Kazutoyo; Oyadomari, Seiichi; Inomata, Yukihiro; Mori, Masataka; Gotoh, Tomomi
Carbon tetrachloride (CCl4) induces liver damage, apparently through the formation of free-radical metabolites. Molecular chaperones such as heat shock protein (Hsp) of 70 kDa have been found to protect cells from various stresses. We previously found that cytosolic chaperone pairs of the Hsp70 family and their DnaJ homolog cochaperones prevent nitric oxidemediated apoptosis and heat-induced cell death. Expression of cytosolic chaperones, including Hsp70; heat shock cognate (Hsc) 70; and DnaJ homologs dj1 (DjB1/Hsp40/hdj-1), dj2 (DjA1/HSDJ/hdj-2), dj3 (DjA2), and dj4 (DjA4), in the liver of CCl4-treated rats was analyzed. Messenger ribonucleic acids for all these chaperones were markedly induced 312 hours...
200.
Serum and lymphocyte levels of heat shock protein 70 in aging: a study in the normal Chinese population - Jin, Xingfang; Wang, Ruibo; Xiao, Chengfeng; Cheng, Longxian; Wang, Feng; Yang, Li; Feng, Taoyi; Chen, Ming; Chen, Sheng; Fu, Xiaoye; Deng, Jie; Wang, Ru; Tang, Fangfang; Wei, Qingyi; Tanguay, Robert M.; Wu, Tangchun
Heat shock proteins (Hsps) have been reported to play an important role in both physiological and pathological processes. Hsps also may serve as biomarkers for evaluating disease states and exposure to environmental stresses. Whether Hsp levels in serum and lymphocytes are correlated with age and sex is largely unknown. In this study, we analyzed serum Hsp70 (the most abundant mammalian Hsp) levels by using Western dot blot in 327 healthy male donors aged between 15 and 50 years. We also investigated the association between Hsp70 levels and age in lymphocytes of 80 normal individuals aged between 40 and 77 years...
181.
