PERSPECTIVES ANDUMMARY .............................................................. 632 HSP110 .................................................................................................. 634 THE HSP 90 FAMILY .............................................................................. 634 Biochemical Analysis ..............................................................................

Adaptation to heat may occur through acclimatization or thermotolerance; however, the linkage of these phenomena is poorly understood. The importance of heat shock proteins (HSPs) in thermotolerance and differences in their accumulation in organisms adapted to the heat suggest a role for HSPs in acclimatization as well. The role of HSPs in heat adaptation of the whole organism and the interrela...

Pretreatment with mild heat shock is known to protect cells from severe stress (acquired thermotolerance). Here we addressed the mechanism of this phenomenon by using primary human fibroblasts. Severe heat shock (45 degrees C, 75 min) of the fibroblasts caused cell death displaying morphological characteristics of apoptosis; however, it was caspase independent. This cell death process was accom...

Increasing evidence suggests that heat acclimation and exogenous salicylic acid (SA) and abscisic acid (ABA) may lead to the enhancement of thermotolerance in plants. In this study, the roles that free SA, conjugated SA, ABA, and phosphatidylinositol-4,5-bisphosphate (PIP(2))-specific phospholipase C (PLC) play in thermotolerance development induced by heat acclimation (38 degrees C) were inves...

BACKGROUND Thermotolerance is an essential attribute for pathogenesis of Cryptococcus as exemplified by the fact that only two species in the genus, which can grow at 37°C, are human pathogens. Species which have other virulence factors including capsule formation and melanisation, but lack the ability to propagate at 37°C are not pathogenic. In another related fungal pathogen, Candida albicans...

Mouse fibroblast LM cells have been modified with respect to the content of polyunsaturated fatty acyl (PUFA) chains of the membrane phospholipids. The membranes of the modified cells were enriched in PUFA chains and were more fluid as compared to the normal cells, as judged by fluorescence polarization measurements. The thermosensitivity of the PUFA-substituted cells was enhanced. Thermotolera...

UNLABELLED Increased oxidative stress is associated with various diseases and aging, while adaptation to heat stress is an important determinant of survival and contributes to longevity. However, the impact of oxidative stress on heat resistance remains largely unclear. AIM In this study we investigated how oxidative stress impinges on heat stress responses. RESULTS We report that hydrogen-...

HA-1 Chinese hamster fibroblasts and two heat-resistant variants, designated 2242 and 3012. have been investigated to determine the role that glutathione (GSH) plays in intrinsic cellular resistance to heat and in the development of thermotolerance. The constitutive levels of GSH did not correlate with intrinsic heat sensitivities, but depletion of GSH sensitized all three cell lines to thermal...

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...

To test whether expression of the inducible heat-shock protein Hsp70 increases under selection for inducible thermotolerance in Drosophila melanogaster, we performed artificial selection on replicate sets of Drosophila lines founded from two independent populations. Selection entailed pretreatment at 36 degrees C to induce thermotolerance and Hsp70 expression, followed by a more severe heat sho...