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 101 - 120 de 951
101.
Surface binding and uptake of heat shock protein 70 by antigen-presenting cells require all 3 domains of the molecule - Zimmer, Christine; Henics, Tamás
The surprisingly efficient uptake of peptide-loaded heat shock proteins (Hsps) by antigen-presenting cells (APCs) has been recently associated with a specific receptor-ligandbased mechanism, and the identity of at least 1 receptor has been determined. In this study, we tested how the domain composition of the stress protein affected its surface association and internalization by APCs, and this was facilitated by the availability of the 70-kDa human heat shock protein (Hsp70) and its various deletion mutants. We show that both these processes strictly depend on the presence of all 3 domains of Hsp70. We propose that the previously described interdomain interactions...
102.
Hsp70 expression in thermally stressed Ostrea edulis, a commercially important oyster in Europe - Piano, Annamaria; Asirelli, Christian; Caselli, Federico; Fabbri, Elena
Synthesis of heat shock proteins (Hsps) in response to elevated temperatures and other denaturing agents is a common feature of prokaryotic and eukaryotic cells. The heat-induced expression of Hsp70 family members in the gills and mantle of Ostrea edulis, a highly valued fisheries resource inhabiting primarily estuarine environments, has been studied. O edulis is exposed to a variety of natural and anthropogenic stresses in the environment. Two isoforms of about 72 kDa and 77 kDa were constitutively present in unstressed organisms, reflecting the housekeeping function performed by these proteins under normal circumstances. Their expression in animals undergoing thermal stress was...
103.
Small glutamine-rich protein/viral protein Ubinding protein is a novel cochaperone that affects heat shock protein 70 activity - Angeletti, Peter C.; Walker, Doriann; Panganiban, Antonito T.
Molecular chaperone complexes containing heat shock protein (Hsp) 70 and Hsp90 are regulated by cochaperones, including a subclass of regulators, such as Hsp70 interacting protein (Hip), C-terminus of Hsp70 interacting protein (CHIP), and Hsp70-Hsp90 organizing factor (Hop), that contain tetratricopeptide repeats (TPRs), where Hsp70 refers to Hsp70 and its nearly identical constitutive counterpart, Hsc70, together. These proteins interact with the Hsp70 to regulate adenosine triphosphatase (ATPase) and folding activities or to generate the chaperone complex. Here we provide evidence that small glutamine-rich protein/viral protein Ubinding protein (SGT/UBP) is a cochaperone that negatively regulates Hsp70. By Far-Western and pull-down assays, SGT/UBP...
104.
Heat shock protein-27 protects human bronchial epithelial cells against oxidative stressmediated apoptosis: possible implication in asthma - Merendino, Anna M.; Paul, Catherine; Vignola, Antonio M.; Costa, Maria A.; Melis, Mario; Chiappara, Giuseppina; Izzo, V.; Bousquet, J.; Arrigo, André-Patrick
Inflammation of the human bronchial epithelium, as observed in asthmatics, is characterized by the selective death of the columnar epithelial cells, which desquamate from the basal cells. Tissue repair initiates from basal cells that resist inflammation. Here, we have evaluated the extent of apoptosis as well as the Hsp27 level of expression in epithelial cells from bronchial biopsy samples taken from normal and asthmatic subjects. Hsp27 is a chaperone whose expression protects against oxidative stress. We report that in asthmatic subjects the basal epithelium cells express a high level of Hsp27 but no apoptotic morphology. In contrast, apoptotic columnar cells...
105.
Stress protection by a fluorescent Hsp27 chimera that is independent of nuclear translocation or multimeric dissociation - Borrelli, Michael J.; Bernock, Laura J.; Landry, Jacques; Spitz, Douglas R.; Weber, Lee A.; Hickey, Eileen; Freeman, Michael L.; Corry, Peter M.
A chimeric protein consisting of enhanced green fluorescent protein (EGFP) fused to the N-terminus of human Hsp27 conferred stress protection in human A549 lung carcinoma and murine L929 cells that were stably transfected to express the chimera constitutively. The resultant protection was comparable with that in the same cell lines when they were transfected to express corresponding levels of Hsp27. Unlike L929 cells, A549 cells exhibit endogenous Hsp27 expression, whose expression was inhibited in proportion to the amount of fluorescent chimera expressed, suggesting that the A549 cells recognized the latter as Hsp27. Upregulation of Hsp27 or chimeric Hsp27 in all...
106.
Hsp70 and thermal pretreatment mitigate developmental damage caused by mitotic poisons in Drosophila - Isaenko, Olga A.; Karr, Timothy L.; Feder, Martin E.
To assess the ability of the heat-inducible molecular chaperone heat-shock protein 70 (Hsp70) to mitigate a specific developmental lesion, we administered the antimicrotubule drugs vinblastine (VB) and colchicine (COL) to larvae of Drosophila engineered to express differing levels of Hsp70 after heat pretreatment (HP). VB and COL decreased survival during metamorphosis, disrupted development of the adult eye and other structures as well as their precursor imaginal disks, and induced chromosome nondisjunction in the wing imaginal disk as indicated by the somatic mutation and recombination test (SMART) assay. Hsp70-inducing HP reduced many of these effects. For the traits viability, adult eye...
107.
An Hsp70 family chaperone, mortalin/mthsp70/PBP74/Grp75: what, when, and where? - Wadhwa, Renu; Taira, Kazunari; Kaul, Sunil C.
Mortalin/mthsp70/PBP74/Grp75 (called mortalin hereafter), a member of the Hsp70 family of chaperones, was shown to have different subcellular localizations in normal and immortal cells. It has been assigned to multiple subcellular sites and implicated in multiple functions ranging from stress response, intracellular trafficking, antigen processing, control of cell proliferation, differentiation, and tumorigenesis. The present article compiles and reviews information on the multiple sites and functions of mortalin in different organisms. The relevance of its differential distributions and functions in normal and immortal cell phenotypes is discussed.
108.
Chaperonin 60 unfolds its secrets of cellular communication - Maguire, Maria; Coates, Anthony R. M.; Henderson, Brian
The cell biology of the chaperonins (Cpns) has been intensively studied over the past 25 years. These ubiquitous and essential molecules assist proteins to fold into their native state and function to protect proteins from denaturation after stress. The structure of the most widely studied Cpn60, Escherichia coli GroEL, has been solved and its mechanism of protein folding action largely established. But in the last decade, evidence has accumulated to suggest that the Cpn60s have functions in addition to intracellular protein folding, particularly the ability to act as intercellular signals with a wide variety of biological effects. Cpn60 has the...
109.
Lipid interaction differentiates the constitutive and stress-induced heat shock proteins Hsc70 and Hsp70 - Arispe, Nelson; Doh, Michael; De Maio, Antonio
Heat shock proteins play a major role in the process of protein folding, and they have been termed molecular chaperones. Two members of the Hsp70 family, Hsc70 and Hsp70, have a high degree of sequence homology. But they differ in their expression pattern. Hsc70 is constitutively expressed, whereas Hsp70 is stress inducible. These 2 proteins are localized in the cytosol and the nucleus. In addition, they have also been observed in close proximity to cellular membranes. We have recently reported that Hsc70 is capable of interacting with a lipid bilayer forming ion-conductance channels. In the present study, we found that...
110.
The heat shock proteins, Hsp70 and Hsp83, of Leishmania infantum are mitogens for mouse B cells - Rico, Ana I.; Gironès, Núria; Fresno, Manuel; Alonso, Carlos; Requena, Jose M.
Extending earlier studies, this report demonstrates that Leishmania infantum heat shock proteins (Hsps), Hsp70 and Hsp83, expressed as recombinant proteins fused to the Escherichia coli maltose-binding protein (MBP), are potent mitogens for murine splenocytes. The response was not due to lipopolysaccharide (LPS) because the stimulatory activity of Hsp preparations was sensitive to boiling and trypsin treatments, whereas the corresponding activity of LPS was resistant to both treatments. It was found that in vitro incubation of spleen cells with the Leishmania Hsps leads to the expansion of CD220-bearing populations, suggesting a direct effect of these proteins on B lymphocytes. In fact,...
111.
Regulation of heat shock proteins, Hsp70 and Hsp64, in heat-shocked Malpighian tubules of Drosophila melanogaster larvae - Lakhotia, Subhash C.; Srivastava, Priya; Prasanth, K. V.
It is known from earlier studies that the heat shock (HS) response in Malpighian tubules (MTs) of Drosophila larvae is different from that in other tissues because instead of the Hsp70 and other common heat shock proteins, Hsp64 and certain other new proteins are induced immediately after HS. In the present study, we examined the kinetics of the synthesis of Hsp70 and Hsp64 immediately after HS and during recovery from HS by 35S-methionine labeling and Western blotting. In addition, we also examined the transcriptional activity of hsp70 genes in larval MT cells at different times after HS by in situ...
112.
Toxoplasma gondiiderived heat shock protein HSP70 functions as a B cell mitogen - Aosai, Fumie; Chen, Mei; Kang, Hyun-Kyu; Mun, Hye-Seong; Norose, Kazumi; Piao, Lian Xun; Kobayashi, Masashi; Takeuchi, Osamu; Akira, Shizuo; Yano, Akihiko
We have investigated the role of Toxoplasma gondiiderived heat shock protein 70 (TgHSP70) as a B cell mitogen by measuring proliferative responses in vitro. TgHSP70 induced prominent proliferative responses in murine B cells derived not only from T gondiiinfected but also from uninfected mice. Nude mice responded to TgHSP70; however, severe combined immunodeficiency, RAG1?/? B6, and ?MT mice failed to respond. B220+ spleen cells showed marked proliferation after stimulation with TgHSP70, but neither CD4+ nor CD8+ population responded. This unresponsiveness of CD4+ and CD8+ T cells to TgHSP70 was antigen presenting cells independent. These data indicate that TgHSP70 induced the...
113.
Inhibition of tumor growth in mice with severe combined immunodeficiency is mediated by heat shock protein 70 (Hsp70)-peptideactivated, CD94 positive natural killer cells - Moser, Christian; Schmidbauer, Christin; Gürtler, Ulrich; Gross, Catharina; Gehrmann, Mathias; Thonigs, Gerald; Pfister, Karin; Multhoff, Gabriele
Previously, we reported that the major stress-inducible heat shock protein 70 (Hsp70) acts as a recognition structure for natural killer (NK) cells, if localized on the cell surface of tumor cells. Incubation of purified NK cells with low-dose interleukin (IL)-2 (100 IU/mL) plus recombinant Hsp70-protein or the immunogenic 14-mer Hsp70-peptide TKDNNLLGRFELSG450463, termed TKD (2 ?g/mL), enhances the cytolytic activity against Hsp70 membrane-positive (CX+) but not against Hsp70-negative (CX?) tumor cells. Here, we show that the cytolytic activity against Hsp70-positive tumor cells is inducible by incubation of unseparated peripheral blood mononuclear cells (PBMNC) with low-dose IL-2 plus TKD. Cell sorting experiments...
114.
Analysis of interactions between domains of a small heat shock protein, Hsp30 of Neurospora crassa - Plesofsky, Nora; Brambl, Robert
The ?-crystallinrelated, small heat shock proteins (sHsps), despite their overall variability in sequence, have discrete regions of conserved sequence that are involved in structural organization, as well as nonconserved regions that may perform similar roles in each protein. Recent X-ray diffraction analyses of an archeal and a plant sHsp have revealed both similarities and differences in how they are organized, suggesting that there is variability, particularly in the oligomeric organization of sHsps. As an adjunct to crystallographic analysis of sHsp structure, we employed the yeast 2-hybrid system to detect interactions between peptide regions of the sHsp of Neurospora crassa, Hsp30....
115.
Differential heat shock gene hsp70-1 response to toxicants revealed by in vivo study of lungs in transgenic mice - Wirth, Delphine; Christians, Elisabeth; Munaut, Carine; Dessy, Cécile; Foidart, Jean-Michel; Gustin, Pascal
Members of heat shock proteins (Hsp70) family have been considered to respond to a large variety of stressful conditions. But it was suggested that, in pulmonary cells, Hsp response depends more closely on the type of stimulus. The lungs are critical organs potentially subjected to air pollution affecting respiratory function and, therefore, these organs are of particular interest with regard to the stress response. To investigate the stress dependence of Hsp70 response in lungs, we created transgenic mice where the firefly luciferase reporter gene is under the control of the murine hsp70-1 promoter and exposed them to different sublethal toxic...
116.
Association of HSP70 and genotoxic damage in lymphocytes of workers exposed to coke-oven emission - Xiao, Chengfeng; Chen, Sheng; Li, Jizhao; Hai, Tao; Lu, Qiaofa; Sun, Enling; Wang, Ruibo; Tanguay, Robert M.; Wu, Tangchun
Heat shock proteins (Hsps) have been reported to protect cells, tissues, and organisms against damage from a wide variety of stressful stimuli. Whether they protect against deoxyribonucleic acid (DNA) damage in individuals exposed to environmental stresses and chemical carcinogens is unknown. In the study, we investigated the association between Hsp70 levels (the most abundant mammalian Hsp) and genotoxic damage in lymphocytes of workers exposed to coke-oven emission using Western dot blot and 2 DNA damage assays, the comet assay and the micronucleus test. The data show that there is a significant increase in Hsp70 levels, DNA damage score, and micronucleus...
117.
Exposure to the metabolic inhibitor sodium azide induces stress protein expression and thermotolerance in the nematode Caenorhabditis elegans - Massie, Michelle R.; Lapoczka, Elizabeth M.; Boggs, Kristy D.; Stine, Karen E.; White, Glenn E.
Historically, sodium azide has been used to anesthetize the nematode Caenorhabditis elegans; however, the mechanism by which it survives this exposure is not understood. In this study, we report that exposure of wild-type C elegans to 10 mM sodium azide for up to 90 minutes confers thermotolerance (defined as significantly increased survival probability [SP] at 37°C) on the animal. In addition, sodium dodecyl sulfatepolyacrylamide gel electrophoresis revealed enhanced Hsp70 expression, whereas Western blot analysis revealed the induction of Hsp16. We also tested the only known C elegans Hsp mutant daf-21 (codes for Hsp90), which constitutively enters the stress-resistant state known...
118.
Analysis of the variation in the hsp70-1 and hsp90? mRNA expression in human myocardial tissue that has undergone surgical stress - Storti, Simona; Vittorini, Simona; Iascone, Maria Rosaria; Sacchelli, Monica; Baroni, Alessandra; Luisi, Vincenzo Stefano; Crucean, Adrian; Vanini, Vittorio; Biagini, Andrea; Clerico, Aldo
In the present work we reported a semiquantitative detection of messenger ribonucleic acids (mRNAs) encoding the human heat shock proteins Hsp70-1, the stress inducible member of the HSP70 family, and hsp90?, the inducible member of the HSP90 family. We investigated the change in the expression of these mRNAs in tissue samples taken from the right atrium of 48 pediatric patients, soon after the ischemic period during surgery to correct congenital heart diseases, in which a crystalloid cold cardioplegic solution was used. No significant variations were found for either hsp70-1 or hsp90? expressions. Moreover, we searched for an association between the...
119.
Hsp25 and Hsp70 in rodent tumors treated with doxorubicin and lovastatin - Ciocca, Daniel R.; Rozados, Viviana R.; Carrión, F. Darío Cuello; Gervasoni, Silvia I.; Matar, Pablo; Scharovsky, O. Graciela
Heat shock protein 27 (Hsp27) and Hsp70 have been involved in resistance to anticancer drugs in human breast cancer cells growing in vitro and in vivo. In this study, we examined the expression of Hsp25 (the rodent homologue to human Hsp27) and Hsp70 in 3 different rodent tumors (a mouse breast carcinoma, a rat sarcoma, and a rat lymphoma maintained by subcutaneous passages) treated in vivo with doxorubicin (DOX) and lovastatin (LOV). All tumors showed massive cell death under control untreated conditions, and this massive death increased after cytotoxic drug administration. In this study, we show that this death was...
120.
Integrin ?v?3 requirement for VEGFR2-mediated activation of SAPK2/p38 and for Hsp90-dependent phosphorylation of focal adhesion kinase in endothelial cells activated by VEGF - Masson-Gadais, Bénédicte; Houle, François; Laferrière, Julie; Huot, Jacques
Endothelial cell migration, a key process in angiogenesis, requires the coordinated integration of motogenic signals elicited by the adhesion of endothelial cells to extracellular matrices and by angiogenic cytokines such as the vascular endothelial growth factor (VEGF). In this study, we found that addition of VEGF to human umbilical vein endothelial cells cultivated on vitronectin triggers a synergistic interaction between the VEGF receptor VEGFR2 and the clustered integrin receptor ?v?3. The interaction between VEGFR2 and ?v?3 is required for full phosphorylation of VEGFR2 and to drive the activation of motogenic pathways involving focal adhesion kinase (FAK) and stress-activated protein kinase-2/p38...
101.
