The role of ergosterol in yeast stress tolerance, together with heat shock proteins (hsps) and trehalose, was examined in a sterol auxotrophic mutant of Saccharomyces cerevisiae. Ergosterol levels paralleled viability data, with cells containing higher levels of the sterol exhibiting greater tolerances to heat and ethanol. Although the mutant synthesised hsps and accumulated trehalose upon heat...

Metabolic syndrome and type 2 diabetes are progressive, indolent, multi-organ diseases. Understanding the abnormalities of heat shock proteins (HSPs) in these diseases is paramount to understanding their pathogenesis. In insulin resistant states and diabetes, heat shock factor 1(HSF-1) is low in insulin sensitive tissues, resulting in low Hsp 60, 70, and 90 levels. We propose that low Hsps leve...

Juvenile salmonid fish readily form dominance hierarchies when faced with limited resources. While these social interactions may result in profound behavioural and physiological stress, it is unknown if this social stress is evident at the level of the cellular stress response--specifically, the induction of stress or heat shock proteins (Hsps). Thus, the goal of our study was to determine if H...

Exposure of cells to elevated temperatures and other environmental stresses results in the expression of specific genes encoding the so-called heat shock proteins (HSPs). Since exogenous H2O2 induces in human monocytes the synthesis of HSPs, and previous induction of HSPs protects these cells from oxidative injury, we investigated whether HSP synthesis was also induced during generation of reac...

An accumulation in cells of unfolded proteins is believed to be the common signal triggering the induction of heat shock proteins (hsps). Accordingly, in Saccharomyces cerevisiae, inhibition of protein breakdown at 30 degrees C with the proteasome inhibitor MG132 caused a coordinate induction of many heat shock proteins within 1 to 2 h. Concomitantly, MG132, at concentrations that had little or...

Heat shock proteins appear to be causatively involved in the acquisition of thermotolerance in prokaryotes but not in eukaryotes. Further, the enhanced synthesis of hsps may be necessary for some cellular responses to stress but not others. In prokaryotic cells the development of thermotolerance, as measured by cell survival, is dependent upon protein synthesis. However, in eukaryotes, enhanced...

22 Phenotypic variation in stress response has been widely observed within species. This 23 variation is an adaptive response to local climates and is controlled by gene sequence 24 variation and especially by variation in expression at the transcriptome level. Plants 25 from contrasting climates are thus expected to have different patterns in gene 26 expression. Acclimation, a pre-exposure to ...

Diverse higher plant species synthesize low molecular weight (LMW) heat shock proteins (HSPs) which localize to chloroplasts. These proteins are homologous to LMW HSPs found in the cytoplasm of all eukaryotes, a class of HSPs whose molecular mode of action is not understood. To obtain basic information concerning the role of chloroplast HSPs, we examined the accumulation, stability, tissue spec...

Heat shock proteins (HSPs) are a large class of proteins that have been conserved throughout evolution and exist by prokaryote and eukaryote organisms. Heat shock proteins play an important role in protein homeostasis. They can found in all major cellular compartments. The HSP90 family are important in the formation of the steroid receptor complex. The HSP70 family is necessary for protein synt...