Heat shock protein 70 (Hsp70) is thought to play a critical role in the thermotolerance of mammalian cells, presumably due to its chaperone activity. We examined the chaperone activity and cellular heat resistance of a clonal cell line in which overexpression of Hsp70 was transiently induced by means of the tetracycline-regulated gene expression system. This single-cell-line approach circumvent...

Insulin induces the expression of the 70-kDa heat shock protein (Hsp70) in rat hearts. In this study, we examined insulin- and heat shock-treated hearts for improved contractile recovery after 30 min of ischemia, activation of the heat shock transcription factor, and localization of the Hsp70 in relation to dystrophin and alpha-tubulin. Adult male Sprague-Dawley rats were assigned to groups: 1)...

Heat shock preconditioning can enhance locomotor and synaptic performance during subsequent hyperthermia. The molecular basis underlying this neural phenotypic modification is largely unknown. Here we report that directing the expression of the 70 kDa heat shock protein (HSP70) to motoneurons protected larval locomotor activity of Drosophila. Tissue-specific expression showed that motoneurons w...

We have studied the expression of the major heat shock protein HSP70 during maturation of avian erythroid cells. Primitive and definitive erythroid cells were isolated from staged day 3-8 chicken embryos, and the levels of HSP70 mRNA and protein synthesis were examined. The highest levels of HSP70 are detected in polychromatic cells of the day 3-4 primitive erythroid cell. After the initial bur...

In asynchronous populations of HeLa cells maintained at control or heat shock temperatures, HSP70 levels and its subcellular distribution exhibit substantial heterogeneity as demonstrated by indirect immunofluorescence with HSP70-specific monoclonal antibodies. Of particular interest is a subpopulation of cells in which the characteristic nuclear accumulation and nucleolar association of HSP70 ...

The role of heat shock proteins (HSPs) in heat tolerance has been demonstrated in cultured cells and animal tissues, but rarely in whole organisms because of methodological difficulties associated with gene manipulation. By comparing HSP70 expression patterns among representative species of reptiles and birds, and by determining the effect of HSP70 overexpression on embryonic development and ha...

In this study we have examined the expression of a heat-shock protein (HSP) 70 gene in normal human peripheral blood leukocytes. Northern blot analysis showed that appreciable levels of hsp70 mRNA are present in monocytes and granulocytes, whereas transcript levels were barely detectable or absent in lymphocytes. Monocytes functionally activated by bacterial lipopolysaccharide (LPS) showed an e...

We have analysed the transcription of three heat-shock genes, HSP70, HSP83 and ClpB, in the protozoan parasite Leishmania. All three heat-shock genes are transcribed constitutively and not heat-inducibly. However, we find that two major heat-shock proteins, HSP70 and HSP83, are synthesized at elevated rates during heat stress. We conclude that the cellular stress response in Leishmaniae is regu...

The functional relationship between thermotolerance and heat shock protein (HSP) expression is well described. However, the intraspecific variation in HSP70 expression and heat resistance is not fully understood. Some studies have shown a correlation between thermotolerance and HSP70 expression levels at the intraspecific level, whereas others have not, and results depend on species, developmen...

The objective of this study was to investigate the expression and localization of heat shock protein 70 (Hsp70) and its mRNA in the heart, liver, and kidney of acutely heat-stressed broilers at various stressing times. Male AA broilers (n = 100) were randomly divided into 5 groups of 20 birds per group. After 30 d of adaptive feeding at ambient temperature, 80 experimental broilers were suddenl...