Cells may sense heat shock via the accumulation of thermally misfolded proteins. To explore this possibility, we determined the effect of protein misfolding on gene expression in the absence of temperature changes. The imino acid analog azetidine-2-carboxylic acid (AZC) is incorporated into protein competitively with proline and causes reduced thermal stability or misfolding. We found that addi...

Elevation of the incubation temperature of Chinook salmon embryo cells from 20 to 24 degrees C or exposure to heavy metals such as CdCl2 (5 microM) or ZnCl2 (100 to 500 microM) induces the reversible expression of a set of heat shock or stress proteins. Continuous exposure of the cells to either metal ions or heat shock results in recovery of protein synthesis to a control-like pattern. Treatme...

Heat shock protects against myocardial ischemia-reperfusion injury possibly via increased expression of heat shock proteins. The direct evidence of heat shock protein protection in vivo remains circumstantial, and no other new mechanism of protection has been proposed. Recent studies suggest that opening of ATP-sensitive K+ channels (KATP channels) plays an important role in ischemic preconditi...

Overexpression of heat shock protein 70 kDa alters the susceptibility of tumor cells to chemotherapeutic agents. We conducted experiments to study the regulation of expression of heat shock proteins (HSPs) in heat shock-treated T47-D cells, a human breast cancer cell line that expresses estrogen receptors. Cells exposed to heat shock at 44 degreesC displayed increased expression of heat shock p...

Background: Varicocele is a major cause of male infertility, as it may impair spermatogenesis through several distinct pathophysiological mechanisms including hypoxia, renal-adrenal reflux, hormonal dysfunction, autoimmunity, oxidative stress and hyperthermia. HSP70s are members of the heat shock protein (HSP) family, which are considered intracellular chaperones. Their expressions can increase...

Title Heat phock protein hsp70 overexpression protects cells from heat shock stress in mouse neuroblastoma x glioma hybrid cells To elucidate cellular concepts for protection against heat shock, we investigated the effect of heat shock protein (hsp70) overexpression on the receptor-mediated intracellular Ca 2 + mobilization in mouse neuroblastoma x glioma hybrid (NG108-15) cells. In sham transf...

Chinese hamster ovary cells were exposed in vitro to various concentrations of diamide for 1 h at 37 degrees C. This treatment resulted in a dose dependent increase in cytotoxicity. Cells were also heated at 43 degrees C for 15 min, incubated at 37 degrees C for 3 h, and then exposed to various concentrations of diamide. This heat shock has been shown previously to trigger the synthesis of heat...

Here we present an in vivo footprinting analysis of the Saccharomyces cerevisiae HSP82 promoter. Consistent with current models, we find that yeast heat shock factor (HSF) binds to strong heat shock elements (HSEs) in non-heat-shocked cells. Upon heat shock, however, additional binding of HSF becomes apparent at weak HSEs of the promoter as well. Recovery from heat shock results in a dramatic r...

A mild heat shock at 35 degrees C, which induces heat shock gene expression, greatly enhances survival and the recovery of protein synthesis in Drosophila cells after a higher temperature heat shock. The 35 degrees C treatment is also effective in preventing heat-induced developmental defects in pupae. We show here that the major larval mRNAs are present in approximately normal (25 degrees C) c...

We have previously demonstrated an estrogen-regulated protein, termed 24K, in human breast cancer cell lines and human tumor biopsies. The presence of the protein correlates well with the presence of steroid hormone receptors. We have cloned a partial complementary DNA to 24K and show that the nucleotide and deduced amino acid sequence contains a striking homology to the low molecular weight he...