Search results for "heat-shock proteins"
showing 10 items of 310 documents
Heat shock response in yeast involver changes in both transcription rates and mRNA stabilities
2011
We have analyzed the heat stress response in the yeast Saccharomyces cerevisiae by determining mRNA levels and transcription rates for the whole transcriptome after a shift from 25uC to 37uC. Using an established mathematical algorithm, theoretical mRNA decay rates have also been calculated from the experimental data. We have verified the mathematical predictions for selected genes by determining their mRNA decay rates at different times during heat stress response using the regulatable tetO promoter. This study indicates that the yeast response to heat shock is not only due to changes in transcription rates, but also to changes in the mRNA stabilities. mRNA stability is affected in 62% of …
Principal component analysis on molecular descriptors as an alternative point of view in the search of new Hsp90 inhibitors
2009
Inhibiting a protein that regulates multiple signal transduction pathways in cancer cells is an attractive goal for cancer therapy. Heat shock protein 90 (Hsp90) is one of the most promising molecular targets for such an approach. In fact, Hsp90 is a ubiquitous molecular chaperone protein that is involved in folding, activating and assembling of many key mediators of signal transduction, cellular growth, differentiation, stress-response and apoptothic pathways. With the aim to analyze which molecular descriptors have the higher importance in the binding interactions of these classes, we first performed molecular docking experiments on the 187 Hsp90 inhibitors included in the BindingDB, a pu…
Different immunohistochemical levels of Hsp60 and Hsp70 in a subset of brain tumors and putative role of Hsp60 in neuroepithelial tumorigenesis
2013
In this work we analysed, by immunohistochemistry, a series of brain tumors to detect the levels and cellular distribution of Hsp60 and Hsp70. We found that Hsp60 levels were significantly higher than those of Hsp70 in neuroepithelial tumors, while levels of both molecules were not significantly different from each other in meningeal neoplasms. In particular, Hsp60 immunopositivity was present mainly at the cytoplasmic level, while Hsp70 immunopositivity was found both in the cytoplasm and in the nucleus of tumor cells. The levels of these molecules in healthy control cells were always very low. Finally, Hsp60 and Hsp70 levels did not correlate with the different types (WHO grade) of neopla…
HSP90 and eNOS partially co-localize and change cellular localization in relation to different ECM components in 2D and 3D cultures of adult rat card…
2007
Background information. Cultivation techniques promoting three-dimensional organization of mammalian cells are of increasing interest, since they confer key functionalities of the native ECM (extracellular matrix) with a power for regenerative medicine applications. Since ECM compliance influences a number of cell functions, Matrigel-based gels have become attractive tools, because of the ease with which their mechanical properties can be controlled. In the present study, we took advantage of the chemical and mechanical tunability of commonly used cell culture substrates, and co-cultures to evaluate, on both two- and three-dimensional cultivated adult rat cardiomyocytes, the impact of ECM c…
Targeting heat shock proteins in cancer
2010
Heat shock proteins (HSPs) HSP27, HSP70 and HSP90 are powerful chaperones. Their expression is induced in response to a wide variety of physiological and environmental insults including anti-cancer chemotherapy, thus allowing the cell to survive to lethal conditions. Different functions of HSPs have been described to account for their cytoprotective function, including their role as molecular chaperones as they play a central role in the correct folding of misfolded proteins, but also their anti-apoptotic properties. HSPs are often overexpressed in cancer cells and this constitutive expression is necessary for cancer cells' survival. HSPs may have oncogene-like functions and likewise mediat…
Genetic manipulation of HSP26 and YHR087W stress genes may improve fermentative behaviour in wine yeasts under vinification conditions
2008
Throughout wine production yeast cells are affected by a plethora of stress conditions that compromise their ability to carry out the whole process. In recent years important knowledge about the mechanisms involved in stress response in both laboratory and wine yeast strains has been obtained. Several studies have indicated that a correlation exists between stress resistance, expression of stress response genes and fermentative behaviour. In this work we introduce several genetic manipulations in two genes induced by several stress conditions: HSP26 (which encodes a heat shock protein) and YHR087W (encoding a protein of unknown function) in two different wine yeasts, ICV16 and ICV27. These …
Heat shock proteins in three relatedDrosophila species belonging to theobscura group
1993
The effect of heat shock on protein synthesis in three related Drosophila species belonging to the obscura group was analyzed on SDS-acrylamide gels. Four major heat shock proteins (hsps) were found in these species, in which synthesis reaches a maximum at 34 degrees C. Although the higher molecular weight proteins are conserved, differences in size were found for the small hsps in these species. By means of in situ hybridization using D. melanogaster probes for the small hsp genes, it was inferred that the small hsp genes of the obscura group species are clustered at the 27A locus in all three species.
Cloning and sequencing of the dnaK region of Streptomyces coelicolor A3(2)
1993
Abstract The dnaK homologue of Streptomyces coelicolor A3(2) strain M145 has been cloned and sequenced. Nucleotide sequence analysis of a 2.5-kb region revealed an open reading frame (ORF) encoding a predicted DnaK protein of 618 amino acids (Mr = 66 274). The dnaK coding sequence displays extreme codon bias and shows a strong preference for CGY and GGY, for Arg and Gly codons, respectively. The predicted DnaK sequence has a high Lys:Arg ratio which is not typical of streptomycete proteins. The region immediately downstream from dnaK contains an ORF for a GrpE-like protein; the predicted start codon of grpE overlaps the last two codons of dnaK, indicating that the two genes are translationa…
Hsp27 and Hsp60 in human submandibular salivary gland: Quantitative patterns in healthy and cancerous tissues with potential implications for differe…
2021
Tumors of the submandibular salivary gland (SMG) are uncommon but sufficiently frequent for the physician to consider them in routine examinations and for the pathologist to be prepared to differentiate them from other tissue abnormalities. However, scarcity of specimens makes training difficult, a situation compounded by the lack of accepted universal diagnostic guidelines. Furthermore, there is little information on the chaperone system (CS) of the gland, despite the increasing evidence of its participation in carcinogenesis as a biomarker for diagnosis and patient follow up, and in the mechanisms by which the tumor cells thrive. We are investigating this aspect of various tumors, and her…
Induction of Hsp70 by the Herbicide Oxyfluorfen (Goal) in the Egyptian Nile Fish, Oreochromis niloticus
1999
This paper deals with the expression of the biomarker hsp70 in the liver and kidney of the freshwater fish Oreochromis niloticus following exposure to the herbicide oxyfluorfen (Goal). Fishes were exposed to three concentrations, the 96-h LC50 (3 mg/L), the 96-h (1/2)LC50 (1.5 mg/L), and the 96-h (1/4)LC50 (0.75 mg/L) of oxyfluorfen for 6, 15, and 24 days, respectively, and samples were taken at three different time periods for each concentration. The livers responded to the herbicide by an induction of the expression of both the constitutive (hsp75; Mr 75 kDa) and the inducible (hsp73; Mr 73 kDa) hsp70 proteins. In kidney, the herbicide induced a time-dependent increase in the expression o…