scholarly journals Acyadeletion mutant ofEscherichia colidevelops thermotolerance but does not exhibit a heat-shock response

1990 ◽  
Vol 55 (1) ◽  
pp. 1-6 ◽  
Author(s):  
John M. Delaney
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Response ◽  
Receptor Protein ◽  
Wild Type ◽  
E Coli ◽  
Shock Response ◽  
In The Wild ◽  
Shock Proteins

SummaryAn adenyl cyclase deletion mutant (cya) ofE. colifailed to exhibit a heat-shock response even after 30 min at 42 °C. Under these conditions, heat-shock protein synthesis was induced by 10 min in the wild-type strain. These results suggest that synthesis of heat-shock proteins inE. colirequires thecyagene. This hypothesis is supported by the finding that a presumptive cyclic AMP receptor protein (CRP) binding site exists within the promotor region of theE. coli htp Rgene. In spite of the absence of heat-shock protein synthesis, when treated at 50 °C, thecyamutant is relatively more heat resistant than wild type. Furthermore, when heat shocked at 42 °C prior to exposure at 50 °C, thecyamutant developed thermotolerance. These results suggest that heat-shock protein synthesis is not essential for development of thermotolerance inE. coli.

scholarly journals Heat-shock protein expression is absent in the antarctic fish Trematomus bernacchii (family Nototheniidae)

2000 ◽  
Vol 203 (15) ◽  
pp. 2331-2339 ◽  
Author(s):  
G.E. Hofmann ◽  
B.A. Buckley ◽  
S. Airaksinen ◽  
J.E. Keen ◽  
G.N. Somero
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Response ◽  
Solid Phase ◽  
Antarctic Fish ◽  
Shock Response ◽  
Enhanced Expression ◽  
Trematomus Bernacchii

The heat-shock response, the enhanced expression of one or more classes of molecular chaperones termed heat-shock proteins (hsps) in response to stress induced by high temperatures, is commonly viewed as a ‘universal’ characteristic of organisms. We examined the occurrence of the heat-shock response in a highly cold-adapted, stenothermal Antarctic teleost fish, Trematomus bernacchii, to determine whether this response has persisted in a lineage that has encountered very low and stable temperatures for at least the past 14–25 million years. The patterns of protein synthesis observed in in vivo metabolic labelling experiments that involved injection of (35)S-labelled methionine and cysteine into whole fish previously subjected to a heat stress of 10 degrees C yielded no evidence for synthesis of any size class of heat-shock protein. Parallel in vivo labelling experiments with isolated hepatocytes similarly showed significant amounts of protein synthesis, but no indication of enhanced expression of any class of hsp. The heavy metal cadmium, which is known to induce synthesis of hsps, also failed to alter the pattern of proteins synthesized in hepatocytes. Although stress-induced chaperones could not be detected under any of the experimental condition used, solid-phase antibody (western) analysis revealed that a constitutively expressed 70 kDa chaperone was present in this species, as predicted on the basis of requirements for chaperoning during protein synthesis. Amounts of the constitutively expressed 70 kDa chaperone increased in brain, but not in gill, during 22 days of acclimation to 5 degrees C. The apparent absence of a heat-shock response in this highly stenothermal species is interpreted as an indication that a physiological capacity observed in almost all other organisms has been lost as a result of the absence of positive selection during evolution at stable sub-zero temperatures. Whether the loss of the heat-shock response is due to dysfunctional genes for inducible hsps (loss of open reading frames or functional regulatory regions), unstable messenger RNAs, the absence of a functional heat-shock factor or some other lesion remains to be determined.

scholarly journals Genetic differences in the duration of the lymphocyte heat shock response in mice.

Genetics ◽  
1990 ◽  
Vol 124 (4) ◽  
pp. 949-955
Author(s):  
V K Mohl ◽  
G D Bennett ◽  
R H Finnell
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Heat Shock Response ◽  
Mouse Strains ◽  
Adult Mice ◽  
Shock Response ◽  
Increased Sensitivity ◽  
Shock Proteins ◽  
The Relationship

Abstract Lymphocytes from adult mice bearing a known difference in genetic susceptibility to teratogen-induced exencephaly (SWV/SD, and DBA/2J) were evaluated for changes in protein synthesis following an in vivo heat treatment. Particular attention was paid to changes indicative of the heat shock response, a highly conserved response to environmental insult consisting of induction of a few, highly conserved proteins with simultaneous decreases in normal protein synthesis. The duration of heat shock protein induction in lymphocytes was found to be increased by 1 hr in the teratogen-sensitive SWV/SD strain as compared to the resistant DBA/2J strain. Densitometric analysis revealed a significant decrease in the relative synthesis of at least two non-heat shock proteins (36 kD and 45 kD) in the SWV/SD lymphocytes as compared to DBA/2J cells. The increased sensitivity of protein synthesis to hyperthermia in the SWV/SD lymphocytes were lost in the F1 progeny of reciprocal crosses between SWV/SD and DBA/2J mouse strains. Sensitivity to hyperthermia-induced exencephaly is recessive to resistance in these crosses. The relationship between altered protein synthesis and teratogen susceptibility is discussed.

Physical Activity, Muscle, and the HSP70 Response

1998 ◽  
Vol 23 (3) ◽  
pp. 245-260 ◽  
Author(s):  
J. Lon Kilgore ◽  
Timothy I. Musch ◽  
Christopher R. Ross
Keyword(s):  
Physical Activity ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Shock Protein ◽  
Heat Shock Response ◽  
Shock Response ◽  
Potential Applications ◽  
Shock Proteins ◽  
External Stimuli ◽  
Exercise And Training

Selye (1936) described how organisms react to various external stimuli (i.e., stressors). These reactions generally follow a programmed series of events and help the organism adapt to the imposed stress. The heat shock response is a common cellular reaction to external stressors, including physical activity. A characteristic set of proteins is synthesised shortly after the organism is exposed to stress. Researchers have not determined how heat shock proteins affect the exercise response. However, their role in adaptation to exercise and training might he inferred, since the synthetic patterns correlate well with the stress adaptation syndrome that Selye described. This review addresses the 70 kilodalton heat shock protein family (HSP70), the most strongly induced heat shock proteins. This paper provides an overview of the general heat shock response and a brief review of literature on HSP70 function, structure, regulation, and potential applications. Potential applications in health, exercise, and medicine are provided. Key words: heat shock, protein, exercise

Heat shock proteins affect RNA processing during the heat shock response of Saccharomyces cerevisiae

1991 ◽  
Vol 11 (2) ◽  
pp. 1062-1068
Author(s):  
H J Yost ◽  
S Lindquist
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Synthesis ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Shock Response ◽  
Rna Splicing ◽  
Yeast Cells ◽  
Yeast Saccharomyces Cerevisiae ◽  
Shock Response ◽  
Shock Proteins

In the yeast Saccharomyces cerevisiae, the splicing of mRNA precursors is disrupted by a severe heat shock. Mild heat treatments prior to severe heat shock protect splicing from disruption, as was previously reported for Drosophila melanogaster. In contrast to D. melanogaster, protein synthesis during the pretreatment is not required to protect splicing in yeast cells. However, protein synthesis is required for the rapid recovery of splicing once it has been disrupted by a sudden severe heat shock. Mutations in two classes of yeast hsp genes affect the pattern of RNA splicing during the heat shock response. First, certain hsp70 mutants, which overproduce other heat shock proteins at normal temperatures, show constitutive protection of splicing at high temperatures and do not require pretreatment. Second, in hsp104 mutants, the recovery of RNA splicing after a severe heat shock is delayed compared with wild-type cells. These results indicate a greater degree of specialization in the protective functions of hsps than has previously been suspected. Some of the proteins (e.g., members of the hsp70 and hsp82 gene families) help to maintain normal cellular processes at higher temperatures. The particular function of hsp104, at least in splicing, is to facilitate recovery of the process once it has been disrupted.

scholarly journals DnaK Chaperone-Mediated Control of Activity of a ς32 Homolog (RpoH) Plays a Major Role in the Heat Shock Response of Agrobacterium tumefaciens

2001 ◽  
Vol 183 (18) ◽  
pp. 5302-5310 ◽  
Author(s):  
Kenji Nakahigashi ◽  
Hideki Yanagi ◽  
Takashi Yura
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Heat Shock ◽  
Heat Shock Response ◽  
Induction Phase ◽  
Primary Role ◽  
E Coli ◽  
Essentially Normal ◽  
Shock Response ◽  
Shock Proteins ◽  
Adaptation Phase

ABSTRACT RpoH (Escherichia coli ς32 and its homologs) is the central regulator of the heat shock response in gram-negative proteobacteria. Here we studied salient regulatory features of RpoH in Agrobacterium tumefaciens by examining its synthesis, stability, and activity while increasing the temperature from 25 to 37°C. Heat induction of RpoH synthesis occurred at the level of transcription from an RpoH-dependent promoter, coordinately with that of DnaK, and followed by an increase in the RpoH level. Essentially normal induction of heat shock proteins was observed even with a strain that was unable to increase the RpoH level upon heat shock. Moreover, heat-induced accumulation of dnaK mRNA occurred without protein synthesis, showing that preexisting RpoH was sufficient for induction of the heat shock response. These results suggested that controlling the activity, rather than the amount, of RpoH plays a major role in regulation of the heat shock response. In addition, increasing or decreasing the DnaK-DnaJ chaperones specifically reduced or enhanced the RpoH activity, respectively. On the other hand, the RpoH protein was normally stable and remained stable during the induction phase but was destabilized transiently during the adaptation phase. We propose that the DnaK-mediated control of RpoH activity plays a primary role in the induction of heat shock response in A. tumefaciens, in contrast to what has been found in E. coli.

Characterization of the heat-shock response in spinach (Spinacia oleracea L.)

1989 ◽  
Vol 67 (2-3) ◽  
pp. 113-120 ◽  
Author(s):  
Daryl J. Somers ◽  
W. Raymond Cummins ◽  
W. Gary Filion
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Shock Response ◽  
Spinacia Oleracea ◽  
Sodium Dodecyl ◽  
In Vitro Translation ◽  
Spinacia Oleracea L ◽  
Shock Response ◽  
Shock Proteins

Spinach (Spinacia oleracea L. cultivar Longstanding Bloomsdale) grown at 20 °C was subjected to a range of rapid thermal shifts as high as 42 °C. There was a decrease in the level of protein synthesis following heat-shock treatments above 34 °C as indicated by the level of incorporation of L-[35S]methionine. In vivo labelled polypeptides and in vitro translation products of RNA isolated from leaf tissue and analyzed using one-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis and fluorography, indicated that the temperature of induction of all 15 heat-shock proteins in the 20 °C grown plants was 36 °C. In addition, heat-shock RNA was coordinately expressed and the translation of heat-shock proteins was noncoordinate with respect to temperature. Treatment with cycloheximide and with chloramphenicol demonstrated that heat-shock protein synthesis in spinach was restricted to cytosolic ribosomes. Synthesis of some low molecular weight heat-shock proteins were insensitive to actinomycin D, suggesting greater stability of these heat-shock RNAs. The heat-shock polypeptide profile of plants grown at 10 °C was similar to that of plants grown at 20 °C, with 14 heat-shock proteins being induced at 36 °C. The growth temperature did not influence the final array of heat-shock proteins synthesized nor alter the temperature of induction of the heat-shock response.Key words: heat-shock response, heat-shock proteins, Spinacia oleracea.

scholarly journals Metabolic Roles of a Rhodobacter sphaeroides Member of the ς32 Family

1998 ◽  
Vol 180 (1) ◽  
pp. 10-19 ◽  
Author(s):  
Russell K. Karls ◽  
Jacqueline Brooks ◽  
Peter Rossmeissl ◽  
Janelle Luedke ◽  
Timothy J. Donohue
Keyword(s):  
Heat Shock ◽  
Temperature Profile ◽  
Rhodobacter Sphaeroides ◽  
Growth Temperature ◽  
Heat Shock Response ◽  
Anaerobic Respiration ◽  
Wild Type ◽  
Lower Growth ◽  
E Coli ◽  
Shock Response

ABSTRACT We report the role of a gene (rpoH) from the facultative phototroph Rhodobacter sphaeroides that encodes a protein (ς37) similar to Escherichia coliς32 and other members of the heat shock family of eubacterial sigma factors. R. sphaeroides ς37controls genes that function during environmental stress, since anR. sphaeroides ΔRpoH mutant is ∼30-fold more sensitive to the toxic oxyanion tellurite than wild-type cells. However, the ΔRpoH mutant lacks several phenotypes characteristic of E. coli cells lacking ς32. For example, anR. sphaeroides ΔRpoH mutant is not generally defective in phage morphogenesis, since it plates the lytic virus RS1, as well as its wild-type parent. In characterizing the response ofR. sphaeroides to heat, we found that its growth temperature profile is different when cells generate energy by aerobic respiration, anaerobic respiration, or photosynthesis. However, growth of the ΔRpoH mutant is comparable to that of a wild-type strain under each of these conditions. The ΔRpoH mutant mounted a heat shock response when aerobically grown cells were shifted from 30 to 42°C, but it exhibited altered induction kinetics of ∼120-, 85-, 75-, and 65-kDa proteins. There was also reduced accumulation of several presumed heat shock transcripts (rpoD PHS,groESL 1, etc.) when aerobically grown ΔRpoH cells were placed at 42°C. Under aerobic conditions, it appears that another sigma factor enables the ΔRpoH mutant to mount a heat shock response, since either RNA polymerase preparations from an ΔRpoH mutant, reconstituted Eς37, or a holoenzyme containing a 38-kDa protein (ς38) each transcribed E. coliEς32-dependent promoters. The lower growth temperature profile of photosynthetic cells is correlated with a difference in heat-inducible gene expression, since neither wild-type cells or the ΔRpoH mutant mount a typical heat shock response after such cultures were shifted from 30 to 37°C.

Heat-shock response in a tropical Chironomus: seasonal variation in response and the effect of developmental stage and tissue type on heat shock protein synthesis

Genome ◽  
1989 ◽  
Vol 32 (4) ◽  
pp. 676-686 ◽  
Author(s):  
B. B. Nath ◽  
S. C. Lakhotia
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Developmental Stage ◽  
Heat Shock Response ◽  
Polytene Chromosomes ◽  
Malpighian Tubules ◽  
Tissue Type ◽  
Developmental Study ◽  
Shock Response

Examination of heat shock induced transcriptional activity in salivary gland polytene nuclei of a tropical Chironomus, C. striatipennis, revealed nine heat-shock puffs. In 24 °C-reared larvae optimal heat-shock response was seen at 39 °C, while a 41 °C shock was nearly lethal. In a population grown under natural conditions of seasonal variations, the heat-shock response was dependent upon the current ambient temperature. In summer months, response to 39 °C was variable, from complete to no induction of heat-shock puffs in different cells. In control glands from larvae growing at 33–36 °C in summer, heat-shock genes were not active, although in 24 °C-reared larvae, 33 °C already caused partial induction. Unlike the 24 °C-reared population, a 41 °C shock to summer larvae was not lethal. [35S]Methionine-labelled protein synthesis pattern in the summer larvae revealed appreciable accumulation of heat-shock polypeptides in control glands, which possibly autoregulates their further induction and also explains the better thermotolerance of these larvae. In a developmental study of a 24 °C-reared population, some heat-shock polypeptides were found to be commonly synthesized at 39 °C in all the tissues (salivary glands of larvae; Malpighian tubules of larvae, pupae, and adult; adult ovaries), while other heat-shock polypeptides showed apparent tissue and (or) developmental stage specificity. Heat shock protein 70 was most abundantly synthesized in all the tissues examined.Key words: temperature shock, thermotolerance, heat-shock polypeptides, polytene chromosomes, puffs.

scholarly journals Heat shock proteins affect RNA processing during the heat shock response of Saccharomyces cerevisiae.

1991 ◽  
Vol 11 (2) ◽  
pp. 1062-1068 ◽  
Author(s):  
H J Yost ◽  
S Lindquist
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Synthesis ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Shock Response ◽  
Rna Splicing ◽  
Yeast Cells ◽  
Yeast Saccharomyces Cerevisiae ◽  
Shock Response ◽  
Shock Proteins

In the yeast Saccharomyces cerevisiae, the splicing of mRNA precursors is disrupted by a severe heat shock. Mild heat treatments prior to severe heat shock protect splicing from disruption, as was previously reported for Drosophila melanogaster. In contrast to D. melanogaster, protein synthesis during the pretreatment is not required to protect splicing in yeast cells. However, protein synthesis is required for the rapid recovery of splicing once it has been disrupted by a sudden severe heat shock. Mutations in two classes of yeast hsp genes affect the pattern of RNA splicing during the heat shock response. First, certain hsp70 mutants, which overproduce other heat shock proteins at normal temperatures, show constitutive protection of splicing at high temperatures and do not require pretreatment. Second, in hsp104 mutants, the recovery of RNA splicing after a severe heat shock is delayed compared with wild-type cells. These results indicate a greater degree of specialization in the protective functions of hsps than has previously been suspected. Some of the proteins (e.g., members of the hsp70 and hsp82 gene families) help to maintain normal cellular processes at higher temperatures. The particular function of hsp104, at least in splicing, is to facilitate recovery of the process once it has been disrupted.

Urea sensitizes mIMCD3 cells to heat shock-induced apoptosis: protection by NaCl

2001 ◽  
Vol 280 (3) ◽  
pp. C614-C620 ◽  
Author(s):  
Chantal Colmont ◽  
Stéphanie Michelet ◽  
Dominique Guivarc'h ◽  
Germain Rousselet
Keyword(s):  
Heat Shock ◽  
Heat Shock Response ◽  
Heat Sensitivity ◽  
Osmotic Gradient ◽  
Water Reabsorption ◽  
Apoptotic Pathway ◽  
Shock Response ◽  
Induced Apoptosis ◽  
Shock Proteins ◽  
Dose Dependent

Urea, with NaCl, constitutes the osmotic gradient that allows water reabsorption in mammalian kidneys. Because NaCl induces heat shock proteins, we tested the responses to heat shock of mIMCD3 cells adapted to permissive urea and/or NaCl concentrations. We found that heat-induced cell death was stronger after adaptation to 250 mM urea. This effect was reversible, dose dependent, and, interestingly, blunted by 125 mM NaCl. Moreover, we have shown that urea-adapted cells engaged in an apoptotic pathway upon heat shock, as shown by DNA laddering. This sensitization is not linked to a defect in the heat shock response, because the induction of HSP70 was similar in isotonic and urea-adapted cells. Moreover, it is not linked to the presence of urea inside cells, because washing urea away did not restore heat resistance and because applying urea and heat shock at the same time did not lead to heat sensitivity. Together, these results suggest that urea modifies the heat shock response, leading to facilitated apoptosis.

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