Expression of heat shock genes of Neurospora crassa: effect of hyperthermia and other stresses on mRNA levels

1988 ◽  
Vol 66 (2) ◽  
pp. 81-92 ◽  
Author(s):  
Carol A. Curle ◽  
M. Kapoor
Keyword(s):  
Heat Shock ◽  
Neurospora Crassa ◽  
Sodium Arsenite ◽  
Gene Probe ◽  
Mrna Levels ◽  
Hsp 70 ◽  
Northern Blots ◽  
Stressed Cells ◽  
Shock Proteins

Neurospora crassa mycelium was heat shocked for intervals varying from 15–180 min. Heat shock mRNA was monitored by hybridization of Northern blots with the Drosophila hsp-70 gene probe and an inducible member of the yeast hsp-70 gene family, YG100. A 2.7 kilobase (kb) transcript, with homology to these two probes, was detected in cultures shocked for 15 min; its levels increased up to 60–90 min and declined thereafter. Sodium arsenite, too, induced the synthesis of this transcript. An additional, constitutively synthesized 2.4-kb transcript was revealed by hybridization with the yeast probe. The synthesis of this message was terminated during heat shock. Hybridization of Northern blots with the Drosophila actin gene probe demonstrated two size classes, 1.85 and 1.63 kb; the former decreased dramatically following heat shock. Recovery, as assessed by the disappearance of the 2.7-kb hsp-70-mRNA and restoration of the 1.85-kb actin message to the prestress levels, was essentially complete within 60 min of transfer to 28 °C. In vitro translations of RNA from stressed cells showed the heat shock messages to be stable and readily translatable. RNA of cells subjected to heat shock plus CdCl2 showed a higher content of messages for heat shock proteins of 70, 80, and 90 kilodaltons.

Alteration of the protein synthesis pattern in Neurospora crassa cells by hyperthermal and oxidative stress

1987 ◽  
Vol 33 (2) ◽  
pp. 162-168 ◽  
Author(s):  
M. Kapoor ◽  
J. Lewis
Keyword(s):  
Oxidative Stress ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Neurospora Crassa ◽  
Sodium Arsenite ◽  
Dna Binding Protein ◽  
Specific Protein ◽  
One Dimensional ◽  
Shock Proteins ◽  
And Oxidative Stress

Neurospora crassa cells, grown at 28 °C for 14 h and heat shocked at 48 °C for 45 min, showed the synthesis of 11 heat-shock proteins (nHSPs) in one-dimensional electrophoretic profiles. Treatment with sodium arsenite induced the synthesis of two heat-shock proteins, nHSP70 and nHSP80, and a third, arsenite-specific protein, not induced by hyperthermia. Exposure to 0.5 or 1.0 mM H2O2 led to the induction of two of the heat-inducible nHSP70 family polypeptides. Sodium selenite, used in concert with H2O2, and arsenite were observed to modulate that heat-shock response. In addition, H2O2, menadione, and the glutathione depleters diamide and diethyl maleate promoted the synthesis of another protein, designated oxidative stress-responsive protein (OSP). A DNA-binding protein, specific for Neurospora DNA, was also demonstrated in extracts of heat-shocked cells.

Heat and nutritional shock-induced proteins of the fungus Achlya are different and under independent transcriptional control

1984 ◽  
Vol 62 (9) ◽  
pp. 837-846 ◽  
Author(s):  
Herb B. LéJohn ◽  
Cleantis E. Braithwaite
Keyword(s):  
Thermal Stress ◽  
Heat Shock ◽  
Transcriptional Control ◽  
Stress Proteins ◽  
Reproductive Development ◽  
Nutritional Stress ◽  
In Vitro Translation ◽  
Stressed Cells ◽  
Shock Proteins

When the temperature of exponentially growing cells of the coenocytic fungus Achlya klebsiana strain 1969 was suddenly elevated from 24 to 37 °C (thermal stress), synthesis of at least 12 preexisting proteins (heat-shock proteins, HSPs) was vigorously induced while synthesis of most other cell proteins declined transiently. After 2–3 h of thermal stress, the cells recovered and resumed normal protein synthesis. If the cells were first starved of nutrients (nutritional stress) before the temperature was raised to 37 °C, the same 12 HSPs were induced, but synthesis of both heat-shock-inducible and nonheat-shock proteins declined to trace levels after 4 h of thermal stress. Molecular weights (MW) of the HSPs were approximately 96 000a, 96 000b, 85 000, 72 000, 70 000, 69 000a, 69 000b, 68 000, 60 000, 52 000, 26 000a, and 26 000b, and they had similar isoelectric points (5.8–6.2). Nutritionally stressed cells showed an induced synthesis of some 28 proteins (nutritional stress proteins, NSPs), when they were not heat shocked, and an induced synthesis of 20 NSPs when heat shocked. In the presence of glutamine, nutritionally stressed cells induced the synthesis of 15 NSPs when they were not heat shocked and 17 NSPs when they were heat shocked. The NSPs and HSPs were electrophoretically different proteins. Glutamine did not affect the induction pattern of the HSPs, but it arrested reproductive development of starving cells while altering the pattern of NSP synthesis. Since actinomycin D inhibited the induced synthesis of HSPs and some NSPs, they may be under transcriptional control. In vitro translation of poly(A)+ RNAs from heat-shocked cells showed that these cells were rich in HSP mRNAs and poor in NSP mRNAs. We speculate that NSPs, but not HSPs, may play a role in reproductive development and sporulation in this fungus.

Heat shock proteins functioning as molecular chaperones: their roles in normal and stressed cells

1993 ◽  
Vol 339 (1289) ◽  
pp. 327-333 ◽  
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Molecular Chaperones ◽  
Stress Proteins ◽  
Elevated Temperatures ◽  
Metabolic Stress ◽  
Hsp 70 ◽  
Degree Of Protection ◽  
Stressed Cells ◽  
Shock Proteins

In response to either elevated temperatures or several other metabolic insults, cells from all organisms respond by increasing the expression of so-called heat shock proteins (hsp or stress proteins). In general, the stress response appears to represent a universal cellular defence mechanism. The increased expression and accumulation of the stress proteins provides the cell with an added degree of protection. Studies over the past few years have revealed a role for some of the stress proteins as being intimately involved in protein maturation. Members of the hsp 70 family, distributed throughout various intracellular compartments, interact transiently with other proteins undergoing synthesis, translocation, or higher ordered assembly. Although not yet proven, it has been suggested that members of the hsp 70 family function to slow down or retard the premature folding of proteins in the course of synthesis and translocation. Yet another family of stress proteins, the hsp 60 or GroEL proteins (chaperonins), appear to function as catalysts of protein folding. Here I discuss the role of those stress proteins functioning as molecular chaperones, both within the normal cell and in the cell subjected to metabolic stress.

Heat shock gene expression in Xenopus laevis A6 cells in response to heat shock and sodium arsenite treatments

1988 ◽  
Vol 66 (8) ◽  
pp. 862-870 ◽  
Author(s):  
S. Darasch ◽  
D. D. Mosser ◽  
N. C. Bols ◽  
J. J. Heikkila
Keyword(s):  
Heat Shock ◽  
Xenopus Laevis ◽  
Sodium Arsenite ◽  
Polyacrylamide Gel Electrophoresis ◽  
Heat Shock Gene ◽  
Epithelial Cell Line ◽  
Continuous Exposure ◽  
Mrna Levels ◽  
Hsp 70 ◽  
Mrna Accumulation

Continuous exposure of a Xenopus laevis kidney epithelial cell line, A6, to either heat shock (33 °C) or sodium arsenite (50 μM) resulted in transient but markedly different temporal patterns of heat-shock protein (HSP) synthesis and HSP 70 and 30 mRNA accumulation. Heat-shock-induced synthesis of HSPs was detectable within 1 h and reached maximum levels by 2–3 h. While sodium arsenite induced the synthesis of some HSPs within 1 h, maximal HSP synthesis did not occur until 12 h. The pattern of HSP 70 and 30 mRNA accumulation was similar to the response observed at the protein level. During recovery from heat shock, a coordinate decline in HSPs and HSP 70 and 30 mRNA was observed. During recovery from sodium arsenite, a similar phenomenon occurred during the initial stages. However, after 6 h of recovery, HSP 70 mRNA levels persisted in contrast to the declining HSP 30 mRNA levels. Two-dimensional polyacrylamide gel electrophoresis revealed the presence of 5 HSPs in the HSP 70 family, of which two were constitutive, and 16 different stress-inducible proteins in the HSP 30 family. In conclusion, heat shock and sodium arsenite induce a similar set of HSPs but maximum synthesis of the HSP is temporally separated by 12–24 h.

scholarly journals Transcriptional and translational regulation of heat shock proteins in leukocytes of endurance runners

2000 ◽  
Vol 89 (2) ◽  
pp. 704-710 ◽  
Author(s):  
Elvira Fehrenbach ◽  
Andreas Michael Niess ◽  
Elke Schlotz ◽  
Frank Passek ◽  
Hans-Herrmann Dickhuth ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Translational Regulation ◽  
Antioxidant Systems ◽  
Mrna Levels ◽  
Adaptive Mechanisms ◽  
Peripheral Leukocytes ◽  
Exercise Induced ◽  
Shock Proteins

Heat shock proteins (HSP) represent cell-protective and antioxidant systems that may be induced by reactive oxygen species, cytokines, and hyperthermia. In the present study, we evaluated the influence of heavy endurance exercise and training on HSP27 and HSP70 in peripheral leukocytes of 12 athletes (before and at 0, 3, and 24 h after a half-marathon) and 12 untrained controls on protein and mRNA levels by flow cytometry and RT/PCR, respectively. HSP transcripts increased significantly immediately after acute exertion accompanied by elevated levels of corresponding proteins. HSP protein expression remained high until 24 h postexercise. Significant increases of plasma interleukin-8, myeloperoxidase, and creatine kinase occurred after exercise. Basal HSP expression was usually lower in trained compared with untrained subjects. Applying in vitro heat shock to resting blood samples of all subjects significantly stimulated HSP mRNA, showing higher increases in trained individuals. The exercise-induced alterations indicate that immunocompetent cells became activated. In addition to heat stress, other exercise-associated stress agents (oxidants, cytokines) may have also participated in stimulation of HSP expression in leukocytes. The expression pattern of HSP due to training status may be attributed to adaptive mechanisms.

scholarly journals Characterization of the stress-inducing effects of homocysteine

1998 ◽  
Vol 332 (1) ◽  
pp. 213-221 ◽  
Author(s):  
P. Andrew OUTINEN ◽  
Sudesh K. SOOD ◽  
Patricia C. Y. LIAW ◽  
Kevin D. SARGE ◽  
Nobuyo MAEDA ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Heat Shock ◽  
Umbilical Vein ◽  
Mrna Levels ◽  
Stress Response Genes ◽  
Umbilical Vein Endothelial Cells ◽  
Shock Proteins

The mechanism by which homocysteine causes endothelial cell (EC) injury and/or dysfunction is not fully understood. To examine the stress-inducing effects of homocysteine on ECs, mRNA differential display and cDNA microarrays were used to evaluate changes in gene expression in cultured human umbilical-vein endothelial cells (HUVEC) exposed to homocysteine. Here we show that homocysteine increases the expression of GRP78 and GADD153, stress-response genes induced by agents or conditions that adversely affect the function of the endoplasmic reticulum (ER). Induction of GRP78 was specific for homocysteine because other thiol-containing amino acids, heat shock or H2O2 did not appreciably increase GRP78 mRNA levels. Homocysteine failed to elicit an oxidative stress response in HUVEC because it had no effect on the expression of heat shock proteins (HSPs) including HSP70, nor did it activate heat shock transcription factor 1. Furthermore homocysteine blocked the H2O2-induced expression of HSP70. In support of our findings in vitro, steady-state mRNA levels of GRP78, but not HSP70, were elevated in the livers of cystathionine β-synthase-deficient mice with hyperhomocysteinaemia. These studies indicate that the activation of stress response genes by homocysteine involves reductive stress leading to altered ER function and is in contrast with that of most other EC perturbants. The observation that homocysteine also decreases the expression of the antioxidant enzymes glutathione peroxidase and natural killer-enhancing factor B suggests that homocysteine could potentially enhance the cytotoxic effect of agents or conditions known to cause oxidative stress.

In Vitro Holdase Activity of E. coli Small Heat-Shock Proteins IbpA, IbpB and IbpAB: A Biophysical Study with Some Unconventional Techniques

2014 ◽  
Vol 21 (6) ◽  
pp. 564-571 ◽  
Author(s):  
Sourav Roy ◽  
Monobesh Patra ◽  
Suman Nandy ◽  
Milon Banik ◽  
Rakhi Dasgupta ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Small Heat Shock Proteins ◽  
E Coli ◽  
Biophysical Study ◽  
Shock Proteins

Ethanol and carbon-source starvation enhance the accumulation of HSP80 in Neurospora crassa

1988 ◽  
Vol 34 (2) ◽  
pp. 162-168 ◽  
Author(s):  
H. S. Roychowdhury ◽  
M. Kapoor
Keyword(s):  
Heat Shock ◽  
Neurospora Crassa ◽  
Carbon Catabolite Repression ◽  
Normal Growth ◽  
Carbon Starvation ◽  
High Molecular Mass ◽  
Sucrose Starvation ◽  
Shock Response ◽  
Shock Proteins ◽  
Starvation Conditions

In Neurospora crassa, heat shock results in the induction of 9 to 11 heat shock proteins (HSP), of which HSP80 is the most abundant and the first to be synthesized. The induction of HSP80 was investigated during normal growth (2% sucrose) and under sucrose starvation. Transfer of mycelium to a medium supplemented with ethanol stimulated the synthesis of HSP80, even at the normal growth temperature of 28 °C. It was also synthesized under carbon starvation conditions, where the medium was supplemented with 0.02% sucrose, 0.3% acetate, 0.2% lactate, or ethanol. A 30–35 kilodalton polypeptide was induced by heat shock in carbon-sufficient media, but in 0.02% sucrose and 0.3% acetate containing media it was synthesized at normal temperatures. While the overall heat shock response remained unaltered in these cultures, the abundance of HSP90 and HSP70, relative to HSP80, was greater. HSP80 appears to be controlled by carbon-catabolite repression as well as heat shock. Another high molecular mass protein (tentatively designated alc'80') was observed to be induced by heat shock, provided carbon starvation conditions prevailed concurrently.

Translation of Some Maize Small Heat Shock Proteins Is Initiated From Internal In-Frame AUGs

Genetics ◽  
1998 ◽  
Vol 148 (1) ◽  
pp. 471-477
Author(s):  
J Roger H Frappier ◽  
David B Walden ◽  
Burr G Atkinson
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Single Gene ◽  
Small Heat Shock Proteins ◽  
Shock Proteins

Abstract Etiolated maize radicles (inbred Oh43) subjected to a brief heat shock synthesize a family of small heat shock proteins (≃18 kD) that is composed of at least 12 members. We previously described the cDNA-derived sequence of three maize shsp mRNAs (cMHSP18-1, cMHSP18-3, and cMHSP18-9). In this report, we demonstrate that the mRNA transcribed in vitro from one of these cDNAs (cMHSP 18-9) is responsible for the synthesis of three members of the shsp family, and we suggest that cMHSP18-3 may be responsible for the synthesis of three additional members and cMHSP18-1 for the synthesis of two other members of this family. The fact that these genes do not contain introns, coupled with the observations reported herein, suggest that maize may have established another method of using a single gene to produce a number of different proteins.

scholarly journals In vivo growth of a murine lymphoma cell line alters regulation of expression of HSP72.

1995 ◽  
Vol 15 (2) ◽  
pp. 1071-1078 ◽  
Author(s):  
S Davidson ◽  
P Høj ◽  
T Gabriele ◽  
R L Anderson
Keyword(s):  
Heat Shock ◽  
Cell Line ◽  
B Cell Lymphoma ◽  
Lymphoma Cell ◽  
Lymphoma Cell Line ◽  
Regulation Of Expression ◽  
Heat Shock Element ◽  
Stressed Cells

We have identified a murine B-cell lymphoma cell line, CH1, that has a much-diminished capacity to express increased levels of heat shock proteins in response to heat stress in vitro. In particular, these cells cannot synthesize the inducible 72-kDa heat shock protein (HSP72) which is normally expressed at high levels in stressed cells. We show here that CH1 fails to transcribe HSP72 mRNA after heat shock, even though the heat shock transcription factor, HSF, is activated correctly. After heat shock, HSF from CH1 is found in the nucleus and is phosphorylated, trimerized, and capable of binding the heat shock element. We propose that additional signals which CH1 cells are unable to transduce are normally required to activate hsp72 transcription in vitro. Surprisingly, we have found that when the CH1 cells are heated in situ in a mouse, they show normal expression of HSP72 mRNA and protein. Therefore, CH1 cells have a functional hsp72 gene which can be transcribed and translated when the cells are in an appropriate environment. A diffusible factor present in ascites fluid is capable of restoring normal HSP72 induction in CH1 cells. We conclude that as-yet-undefined factors are required for regulation of the hsp72 gene or, alternatively, that heat shock in vivo causes activation of hsp70 through a novel pathway which the defect in CH1 has exposed and which is distinct from that operating in vitro. This unique system offers an opportunity to study a physiologically relevant pathway of heat shock induction and to biochemically define effectors involved in the mammalian stress response.

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