scholarly journals Is the major Drosophila heat shock protein present in cells that have not been heat shocked?

1983 ◽  
Vol 96 (1) ◽  
pp. 286-290 ◽  
Author(s):  
J M Velazquez ◽  
S Sonoda ◽  
G Bugaisky ◽  
S Lindquist
Keyword(s):  
Heat Shock ◽  
Elevated Temperatures ◽  
Essential Element ◽  
Culture Conditions ◽  
Hsp 70 ◽  
Cloned Gene ◽  
Shock Proteins ◽  
Drosophila Cells ◽  
In Cells

When eukaryotic cells are exposed to elevated temperatures they respond by vigorously synthesizing a small group of proteins called the heat shock proteins. An essential element in defining the role of these proteins is determining whether they are unique to a stressed state or are also found in healthy, rapidly growing cells at normal temperatures. To date, there have been conflicting reports concerning the major heat-induced protein of Drosophila cells, HSP 70. We report the development of monoclonal antibodies specific for this protein. These antibodies were used to assay HSP 70 in cells incubated under different culture conditions. The protein was detectable in cells maintained at normal temperatures, but only when immunological techniques were pushed to the limits of their sensitivity. To test for the possibility that these cells contain a reservoir of protein in a cryptic antigenic state (i.e., waiting posttranslational modification for use at high temperature), we treated cells with cycloheximide or actinomycin D immediately before heat shock. HSP 70 was not detected in these cells. Finally, we tested for the presence of a reservoir of inactive messages by using a high stringency hybridization of 32P-labeled cloned gene sequences to electrophoretically separated RNAs. Although HSP 70 mRNA was detectable in rapidly growing cells, it was present at less than 1/1,000th the level achieved after induction.

Retinoic acid stimulates the synthesis of a novel heat shock protein in the regenerating forelimb of the newt

1993 ◽  
Vol 71 (1-2) ◽  
pp. 43-50 ◽  
Author(s):  
Robert L. Carlone ◽  
Robert P. Boulianne ◽  
K. Marion Vijh ◽  
Heather Karn ◽  
Gordon A. D. Fraser
Keyword(s):  
Retinoic Acid ◽  
Heat Shock ◽  
Stress Proteins ◽  
Limb Regeneration ◽  
Stress Protein ◽  
Cross Reactivity ◽  
Hsp 70 ◽  
Peptide Map ◽  
Shock Proteins

Morphogenetic effects of retinoic acid (RA) on the urodele amphibian limb regenerate pattern have been well documented, but little is known regarding the mechanism of this action of RA at the molecular level. Since exogenous RA, at concentrations sufficient to cause proximalization, represents a significant stress to newts and has been shown previously to elicit increased synthesis of heat shock proteins (HSPs) in mouse embryo limb buds, we investigated the effects of this putative morphogen on the synthesis of members of the 70-kilodalton (70-kDa) stress protein family in amputated forelimbs of the newt Notophthalmus viridescens. Injection (i.p.) of RA in dimethyl sulfoxide (DMSO), at a dose sufficient to cause significant proximal–distal reduplication of the pattern in 50% of animals treated, resulted in increased synthesis and accumulation of a 73-kDa protein with a pi of approximately 6.75. The synthesis of this same protein is increased in limb tissues as a result of a brief 35 °C heat shock. This protein is electrophoretically distinct from the newt HSP 70 family members, displays a different partial peptide map, and shows no immunological cross-reactivity with an anti-human HSP 70 monoclonal antibody. It may be a member of a separate family of 70- to 73-kDa HSPs. Interestingly, the synthesis of this protein is increased and it is more abundant in control, proximal moderate-early bud stage regenerates at 6 days after i.p. injection of DMSO than in similarly treated distal regenerates. This protein is, in addition, increased in distal regenerates to proximal levels by a prior injection of RA. The significance of these findings with regard to the possible role of stress proteins in the morphogenetic processes underlying limb regeneration is discussed.Key words: heat shock, limb regeneration, retinoic acid, pattern formation, newt.

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.

The role of heat-shock proteins in thermotolerance

1993 ◽  
Vol 339 (1289) ◽  
pp. 279-286 ◽  
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
High Temperatures ◽  
Fruit Fly ◽  
Yeast Cells ◽  
Major Protein ◽  
Wild Type ◽  
Hsp 70 ◽  
Shock Proteins

The role of heat-shock proteins (hsps) in thermotolerance was examined in the budding yeast Saccharomyces cerevisiae and in the fruit fly Drosophila melanogaster . In yeast cells, the major protein responsible for thermotolerance is hsp 100. In cells carrying mutations in the hsp 100 gene, HSP 104 , growth is normal at both high and low temperatures, but the ability of cells to survive extreme temperatures is severely impaired. The loss of thermotolerance is apparently due to the absence of the hsp 104 protein itself because, with the exception of the hsp 104 protein, no differences in protein profiles were observed between mutant and wild-type cells. Aggregates found in mutant cells at high temperatures suggest that the cause of death may be the accumulation of denatured proteins. No differences in the rates of protein degradation were observed between mutant and wild-type cells. This, and genetic analysis of cells carrying multiple hsp 70 and hsp 104 mutations, suggests that the primary function of hsp 104 is to rescue proteins from denaturation rather than to degrade them once they have been denatured. Drosophila cells do not produce a protein in the hsp 100 class in response to high temperatures. In this organism, hsp 70 appears to be the primary protein involved in thermotolerance. Thus, the relative importance of different hsps in thermotolerance changes from organism to organism.

scholarly journals Role of heat-shock proteins and cobalamine in maintaining methionine synthase activity.

2012 ◽  
Vol 59 (4) ◽  
Author(s):  
Michał Grabowski ◽  
Rafał Banasiuk ◽  
Alicja Węgrzyn ◽  
Barbara Kędzierska ◽  
Jan Lica ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Stress Conditions ◽  
Methionine Synthase ◽  
Atheromatous Plaque ◽  
Hsp 70 ◽  
Functional Relations ◽  
Shock Proteins

Atheromatous plaque is one of the most common cardiovascular-related diseases. Reports show a connection between its development and the levels of homocysteine. In pathological states high levels of homocysteine in the organism can be caused by the malfunction of the methionine synthase pathway. Bacterial methionine synthase (MetH) is a homologue of the human methionine syntase (MS). In this study we aimed to investigate the functional relations between MetH and its cofactor--cobalamine--under stress conditions. We have demonstrated that heat shock proteins (Hsp 70/100 system or HtpG) can protect MetH activity under stress conditions. Moreover, in the presence of cobalamine they can restore the activity of partially denatured methionine synthase.

scholarly journals Diagnostic value of chaperone activity of heat shock proteins 70 in coronary atherosclerosis

2019 ◽  
Vol 10 (3) ◽  
pp. 60-64
Author(s):  
Julia A. Kotova ◽  
Anna A. Zuikova ◽  
Alexander N. Pashkov
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Coronary Atherosclerosis ◽  
Negative Relationship ◽  
Diagnostic Value ◽  
Chaperone Activity ◽  
Hsp 70 ◽  
Significant Negative Relationship ◽  
Shock Proteins

Aim. The aim of the research was to study the role of chaperone activity heat shock proteins (HSP) 70 in pathogenesis and diagnostic in patients with coronary atherosclerosis. Materials and methods. We examined 354 patients with coronary heart disease, who had coronary atherosclerosis of varying degrees, according to coronary angiography (was performed by the Judkins technique). The severity of coronary atherosclerosis was determined on the basis of the Gensini index. According to the Gensini index, patients were divided into 2 groups: GS0 - 152 patients without signs of coronary atherosclerosis, GS1 - 202 patients with coronary lesions. Chaperone activity was determined by thermodynamic method. Results. The study showed significant differences in the level of chaperone activity HSP70 in patients with different severity of coronary atherosclerosis. The correlation analysis revealed a significant negative relationship between chaperone activity HSP70 and the Gensini index. The cut-off value of chaperone activity of HSP70, by which can be judged on the presence or absence of coronary atherosclerosis, is establish. Conclusion. The revealed threshold of chaperone activity can be considered as a possible marker of the severity of coronary atherosclerosis.

Thermal Protein Denaturation and Protein Aggregation in Cells Made Thermotolerant by Various Chemicals: Role of Heat Shock Proteins

1995 ◽  
Vol 219 (2) ◽  
pp. 536-546 ◽  
Author(s):  
Harm H. Kampinga ◽  
Jeanette F. Brunsting ◽  
Gerard J.J. Stege ◽  
Paul W.J.J. Burgman ◽  
Antonius W.T. Konings
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Protein Aggregation ◽  
Protein Denaturation ◽  
Shock Proteins ◽  
In Cells

The possible role of the superoxide ion in the induction of heat-shock and specific proteins in aerobic Drosophila cells during return to normoxia after a period of anaerobiosis

1983 ◽  
Vol 61 (6) ◽  
pp. 456-461 ◽  
Author(s):  
M. Ropp ◽  
A. M. Courgeon ◽  
R. Calvayrac ◽  
M. Best-Belpomme
Keyword(s):  
Heat Shock ◽  
Superoxide Ion ◽  
Experimental Conditions ◽  
Transient Period ◽  
Specific Proteins ◽  
Shock Proteins ◽  
Drosophila Cells ◽  
Specific Peptide

In vitro cultured Drosophila melanogaster cells were shown to be aerobic and several kinetic parameters of their respiration were measured. This allowed us to define experimental conditions for a transient period of anaerobiosis followed by a reexposure to normal oxygenation. This treatment, applied without any change of temperature, induced not only the heat-shock proteins, but also a new specific peptide of 27 000 daltons and a twofold increase of the maximal rate of O2 uptake. This evokes a common molecular mechanism activated either by heat or by O2, which could involve the increase of the products of oxygen reduction such as the superoxide ion.

Sign in / Sign up

Export Citation Format

Share Document