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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.

Modular recognition and binding properties of human heat shock transcription factor

Wagner, John, 1966- January 1991 (has links)
A partially purified preparation of in vivo activated human heat shock transcription factor (HSF) has been obtained from HeLa cells and its interaction with the heat shock response element (HSE) in the human Hsp70 gene promoter was investigated. A variety of DNA-protein binding studies including DNAse I protection, hydroxyl radical protection, and diethylpyrocarbonate interference analysis were used to investigate recognition of the HSE by human HSF. Direct contacts to bases within the 5 basepair recognition motif were detected and the overall pattern of binding was compared with the Drosophila results. Analysis of the high resolution protection patterns to extended HSE mutants indicates that HSF binding coincides with the location of the additional element motifs. Moreover, examination of the protection patterns from these constructs indicate that a proposed model for HSF binding is consistent with a model depicting HSF as a trimer.

Hsp72 translocation and secretion in in vivo and in vitro models

Leoni, Francesca January 2009 (has links)
Evidence suggesting that Hsp72 is actively participating in cellular signalling as well interacting with immune system dynamics has been increasing. This is true in healthy, stressed and diseased cells but to different degrees. Modulation of the plasma membrane association and secretion in the extracellular environment by different types of stressors is the key event that leads to different degrees of immune system activation. Hence a better understanding of the mechanisms of Hsp72 secretion and association with plasma membrane is crucial. This thesis investigated the tissue source and mechanism of Hsp72 surface presentation to plasma membrane structures and release in relation with different cellular and physiological stressors. In vivo models confirmed that different tissue types determine specific Hsp72 responses following the same stress and increase serum Hsp72 dependant on intensity and duration of the stress. Diseases models confirm that Hsp72 responses in specific cell populations is related to disease progression, while in vitro models clearly showed that there are multiple mechanisms of secretion and surface presentation, dependent on the nature of the stressor as well as the intensity and duration. This observations clearly change the view of extracellular Hsp72 as a danger signal and lead to a revision of the original danger model. It also suggests that manipulation of Hsp72 translocation through the different pathways involved may prove effective therapeutically.

Localisation of heat shock proteins in haematological malignancies

Dempsey, Nina Claire January 2009 (has links)
Although a number of HSPs have been shown to be up-regulated in a wide range of human cancers, the full significance of this remains to be determined. The localisation of HSPs seems to be critical in determining their role in cancer cell survival; High intracellular levels (iHsp) appear to be advantageous to the tumour cell, inhibiting key steps in apoptosis, while in some circumstances, surface expression (sHsp) appears to be detrimental to the cell, aiding immune recognition by various effector cells. Consequently, clarifying the importance of HSP cellular location in the cancer setting may lead to the development of novel therapies based upon manipulation of HSP localisation. This thesis had two major aims; (1) to investigate the cellular localisation of HSPs in leukocytes from patients with both myelocytic and lymphocytic malignancies in order to establish relationships between apoptosis and stage of disease (2) to study the synergistic effect of four chemotherapeutic drugs with membrane fluidising agents, compounds which have the potential to modulate HSP localisation. Hsp90 and Hsp27 expression was shown to be restricted to the inside of peripheral blood leukocytes, while Hsp72 was localised both intracellularly and on the cell surface. In CLL, iHsp90 and iHsp27 levels were found to be significantly higher than in control subjects, while surface and intracellular Hsp72 was shown to be expressed either at very high levels or at very low levels. Furthermore, iHsp90 levels were found to be associated with stage of disease, while iHsp27 levels were shown to negatively correlate with levels of apoptosis. CLL patients with stable disease were found to express higher levels of iHsp72 than patients with progressive disease. However, in AML and MDS, levels of all HSPs in peripheral blood were found to be similar to those seen in control subjects, but disease patients showed a much wider range of expression. In AML, levels of sHsp72 positively correlated in all cell types, an observation not made in MDS patients or control subjects. HSP localisation was shown to be affected by membrane fluidising agents, with a movement of Hsp72 and Hsp60 to the cell surface. This effect was not due to proteotoxicity and supports data implicating the cell membrane in the regulation of HSP responses. This manipulation of HSP localisation and the increase in membrane fluidity resulted in increased sensitivity of CLL cells to three chemotherapeutic agents and points to the possibility that manipulation of membrane fluidity, may have significant value in the development of new treatment regimes.

An investigation of the response of lymphoid cells to oxidative stress

O'Farrell, Francis J. January 1996 (has links)
No description available.

Characterisation of the heat shock response in Streptomyces lividans

Barratt, Elizabeth M. January 1993 (has links)
No description available.

Regulation and role of the three chaperonin operons of Rhizobium leguminosarum

Gould, Phillip Spencer January 2002 (has links)
No description available.

Mechanistic studies of Hsp90 in neurodegenerative diseases and cancer

Daturpalli, Soumya Srinivas January 2014 (has links)
No description available.

The heat-shock response in Serpula species at the cellular and molecular level

Sienkiewicz, Natasha January 1999 (has links)
The study focuses on the effects of heat stress on <i>Serpula lacrymans</i> and <i>S. himantioides</i> (which have been previously shown to be relatively thermosensitive and thermotolerant respectively) in relation to the heat shock response. A part of this response is the production of heat-shock proteins (hsps). Comparative studies of chick embryo fibroblasts and <i>Saccharomyces cerevisiae</i> (wine strain, L-2226) were used to demonstrate possible differences between these three very distinct eukaryotic systems. The aims of the project were to determine whether <i>S. lacrymans</i> and <i>S. himantioides</i> undergo the heatshock response with respect primarily to induced thermotolerance and the production of hsps. The approach taken to establish the above was by systematic analysis of the different pathways involved in this response. Firstly, overall heat induced changes in protein and mRNA synthesis were analysed, in conjunction with the identification of specific proteins related to the heat-shock response, namely hsp60, hsp70 which have been shown in other eukaryotic systems to play key roles in this response. Secondly, immunological studies were also used to detect changes in the pattern of protein ubiquitination, which resulted from heat stress. Thirdly, changes in hsp70 mRNA were monitored by RT-PCR. The cDNA and genomic amplimer products generated by RT-PCR and PCR respectively were cloned and sequenced to identify a putative of hsp70 gene sequence. Fourthly, the AMP-activated protein kinase (AMPK) cascade has been demonstrated to be activated in response to stress and steps were made to detect and identify AMPK activity in cellular extracts of both <i>Serpula </i>species. Finally, the effect of heat upon trehalose accumulation and mobilisation during the heat-shock response was studied as there is growing evidence to link increased thermotolerance to transient increase in trehalose levels, which is now considered to be a stress metabolite.

Characterization of a small heat shock protein B3 (HSPB3).

January 2000 (has links)
by Wing-Hoi Tam. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 95-99). / Abstracts in English and Chinese. / Title --- p.1 / Acknowledgement --- p.2 / Contents --- p.3 / Abbreviations --- p.5 / List of figures --- p.7 / List of tables --- p.9 / Primers and their sequences used in the projcet --- p.10 / Abstract --- p.12 / Introduction / Small heat shock proteins --- p.16 / Human heart sequencing EST project --- p.17 / Small heat shock protein B3 (HSPB3) --- p.18 / The alpha crystallins --- p.18 / Point mutation of a conserved arginine in the alpha-crystallin domain perturbs the overall alpha crystallins structure and function --- p.19 / HSP27 Confers thermotolerance in cells --- p.19 / Chaperone properties of sHSP --- p.20 / In Viro-chaperone function of sHSPs --- p.21 / Does the alpha-crystallin domain necessary for chaperone activity? --- p.21 / Expression HSPB3 in heart diseases patients and in porcine model --- p.22 / Small heat shock proteins in development and differentiation --- p.23 / HSPB3 role in mammalian embryogenesis --- p.24 / Structure of the small heat shock proteins --- p.25 / Crystal structure of a small heat shock protein --- p.25 / Subunit contacts --- p.26 / Muscle is the only tissue that simultaneously expresses all five sHSPs --- p.26 / "Two independent sHSP systems in muscle cells, to serve and to protect" --- p.27 / Methods and Materials / Small scale preparation of plasmid DNA --- p.29 / Large scale preparation of plasmid DNA --- p.29 / Amplification of mouse and rat HSPB3 coding region --- p.30 / Northern Blotting and Hybridisation --- p.31 / Purification of DNA fragments by GENECLEAN --- p.31 / Preparation of competent Escherichia coli for transformation --- p.32 / Transformation of DNA plasmid into competent Escherichia coli --- p.32 / 5´ة Rapid Amplification of cDNA Ends (5´ةRACE) --- p.33 / 3´ة Rapid Amplification of cDNA Ends (3´ةRACE) --- p.35 / Upstream and Downstream Genomic sequence --- p.36 / Isolation of genomic DNA from human tissue --- p.37 / Multiple tissue cDNA panel (MTC) --- p.37 / The yeast two hybrid screenings and confirmation --- p.43 / Isolation of total RNA from human tissues --- p.43 / Automated Sequencing --- p.44 / Alignment of DNA and amino acid sequence --- p.44 / Radiation hybrid mapping --- p.45 / Results / Determination of the foll length of human HSPB3 cDNA by 5' and 3' RACE --- p.46 / Identification of human HSPB3 gene in mouse and rat heart tissues --- p.49 / "Sequence homology between human, mouse and rat HSPB3" --- p.51 / Chromosomal mapping of the HSPB3 gene --- p.60 / Expression of human HSPB3 is not confined to the heart and skeletal muscle --- p.62 / Mouse HSPB3 expression is confined to the heart tissue --- p.65 / HSPB3 genomic PCR of downstream sequence --- p.67 / HSPB3 upstream genomic sequence --- p.67 / No intronic sequences between the open reading frame --- p.68 / The yeast two hybrid screening --- p.71 / HSPB3 can not form dimers --- p.82 / Expression of Prepro-CDD-ANF in human adult and fetal --- p.83 / Discussions / Previously reported sequence HSPL27 is a chimera --- p.87 / HSPB3 monomers do not dimerises --- p.88 / No intronic sequence in the HSPB3 gene --- p.89 / HSPB3 and CDD-ANF may play an important role during stress to the heart --- p.91 / Change of expression pattern of Prepro-CDD-ANF during development --- p.93 / Reference --- p.95

Interaction of human heat shock factor-1 transcription with promotor DNA

Wang, Ying January 1993 (has links)
Note: Missing pages

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