Induced Expression of the Heat Shock Protein Genes uspA and grpE during Starvation at Low Temperatures and Their Influence on Thermal Resistance of Escherichia coli O157:H7

2003 ◽  
Vol 66 (11) ◽  
pp. 2045-2050 ◽  
Author(s):  
YI ZHANG ◽  
MANSEL W. GRIFFITHS

Heat shock proteins play an important role in protecting bacterial cells against several stresses, including starvation. In this study, the promoters for two genes encoding heat shock proteins involved in many stress responses, UspA and GrpE, were fused with the green fluorescent protein (gfp) gene. Thus, the expression of the two genes could be quantified by measuring the fluorescence emitted by the cells under different environmental conditions. The heat resistance levels of starved and nonstarved cells during storage at 5, 10, and 37°C were compared with the levels of expression of the uspA and grpE genes. D52-values (times required for decimal reductions in count at 52°C) increased by 11.5, 14.6, and 18.5 min when cells were starved for 3 h at 37°C, for 24 h at 10°C, and for 2 days at 5°C, respectively. In all cases, these increases were significant (P < 0.01), indicating that the stress imposed by starvation altered the ability of E. coli O157:H7 to survive subsequent heat treatments. Thermal tolerance was correlative with the induction of UspA and GrpE. At 5°C, the change in the thermal tolerance of the pathogen was positively linked to the induced expression of the grpE gene but negatively related to the expression of the uspA gene. The results obtained in this study indicate that UspA plays an important role in starvation-induced thermal tolerance at 37°C but that GrpE may be more involved in regulating this response at lower temperatures. An improvement in our understanding of the molecular mechanisms involved in these cross-protection responses may make it possible to devise strategies to limit their effects.

2019 ◽  
Vol 34 (2) ◽  
pp. 455-474
Author(s):  
Rafael Guerrero-Rojas ◽  
Carlos Guerrero-Fonsecaz

Parasitology ◽  
2001 ◽  
Vol 122 (5) ◽  
pp. 583-588 ◽  
Author(s):  
L. VARGAS-PARADA ◽  
C. F. SOLÍS ◽  
J. P. LACLETTE

Heat shock and stress responses are documented for the first time in larval stages of the cestodes Taenia solium and Taenia crassiceps. Radioactive metabolic labelling after in vitro incubation of cysts at 43 °C, revealed the induction of heat shock proteins. In T. crassiceps, the major heat shock proteins were 80, 70 and 60 kDa. After prolonged incubation, a set of low molecular weight heat shock proteins (27, 31, 33 and 38 kDa), were also induced. In vitro incubation of cysts at 4 °C, induced the synthesis of stress proteins ranging from 31 to 80 kDa, indicating the parasite is also able to respond to cold shock. T. solium cysts exposure to temperature stress also resulted in an increased synthesis of 2 major heat shock proteins of 80 and 70 kDa. Western blots using the excretory–secretory products of T. solium showed that 2 heat shock proteins were recognized by antibodies in the sera of cysticercotic patients: one of 66 kDa and another migrating close to the run front. The T. solium 66 kDa protein was also recognized by specific antibodies directed to a 60 kDa bacterial heat shock protein, suggesting that it belongs to this family of proteins.


Author(s):  
Michał Rurek ◽  
Magdalena Czołpińska ◽  
Tomasz Andrzej Pawłowski ◽  
Włodzimierz Krzesiński ◽  
Tomasz Spiżewski

Complex proteomic and physiological approaches to study cold and heat stress responses in plant mitochondria are still limited. Variations in the mitochondrial proteome of cauliflower (Brassica oleracea var. botrytis) curds after cold and heat and after stress recovery were assayed by 2D PAGE in relation to respiratory parameters. Quantitative analysis of the mitochondrial proteome revealed numerous stress-affected protein spots. In cold alternative oxidase isoforms were extensively upregulated; major downregulations in the level of photorespiratory enzymes, porine isoforms, oxidative phosphorylation (OXPHOS) and some low-abundant proteins were observed. On the contrary, distinct proteins, including carbohydrate metabolism enzymes, heat-shock proteins, translation, protein import, and OXPHOS components were involved in heat response and recovery. Few metabolic regulations were suggested. Cauliflower plants appeared less susceptible to heat; closed stomata in heat stress resulted in moderate photosynthetic, but only minor respiratory impairments, however photosystem II performance was unaffected. Decreased photorespiration corresponded with proteomic alterations in cold. Our results show that cold and heat stress not only operate in diverse mode (exemplified by cold-specific accumulation of some heat shock proteins), but exert some associations on molecular and physiological levels. This implies more complex model of action of investigated stresses on plant mitochondria.


2018 ◽  
Vol 21 (5) ◽  
pp. 364-375 ◽  
Author(s):  
Ivan I. Dedov ◽  
Vsevolod A. Tkachuk ◽  
Nikolai B. Gusev ◽  
Vladimir P. Shirinsky ◽  
Aleksandr V. Vorotnikov ◽  
...  

Type 2 diabetes mellitus (T2DM) is a socially important disease with only symptomatic therapy developed due to lack of knowledge about its pathogenesis and underlying mechanism. Insulin resistance (IR) is the first link of T2DM pathogenesis and results in decrease of ability of insulin to stimulate glucose uptake by target cells. Development of IR involves genetic predisposition, excessive nutrition, stress, obesity or chronic inflammation due to disruption of insulin signaling within cells. Molecular mechanisms and markers of IR are characterized rather poorly, which prevents early diagnosis and creation of preventive therapy. Euglycemic clamp test is still a golden standard for IR diagnosis in clinic. Hyperglycemia is a distant consequence of IR in which damaging effect of oxidative and carbonyl stress is realized and diagnosis of T2DM is stipulated. Molecular chaperones and small heat-shock proteins have a protective effect at the early stages of T2DM pathogenesis, preventing development of reticulum stress and apoptosis. Endothelial dysfunction is related to T2DM and its cardiovascular complications, however, it is unknown on which stage of pathogenesis these changes occur and what are their molecular inductors. Finally, transcriptional activity and adipogenic differentiation play an important role in formation of new fat depots from predecessor cells and activation of brown and beige fat demonstrating hypolipidemic and hypoglycemic properties. The aim of this study was investigation of pathophysiological mechanisms of development of IR and endothelial dysfunction, role of transcription factor Prep1 and small heat shock proteins, evaluation of novel methods of diagnostics of IR and therapeutic potential of brown and beige fat, determination of biotargets for new antidiabetic drugs.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 691c-691
Author(s):  
Robert E. Paull ◽  
Chris B. Watkins

Production of heat shock proteins (HSP) in response to high temperatures are a highly recognizable feature of plant and animal systems. It is thought that such proteins play a critical role in survival under supraoptimal temperature conditions. The use of heat treatments has been examined extensively, especially for disinfestation of fruit and disease control. Heat treatments can affect physiological responses, such as ethylene production, softening, and other ripening factors, as well as reducing physiological disorders, including chilling injury. HSPs have been implicated in a number of stress responses, but the extent that they are involved, especially in amelioration of chilling injury, is a subject of debate. In a number of cases, heat shock proteins do not appear to be involved, and HSPs do not explain long-term adaptation to heat; other systems for which we do not have models may be at work. Resolution of these issues may require the use of transgenic plants with modified heat shock responses.


1988 ◽  
Vol 34 (10) ◽  
pp. 1148-1153 ◽  
Author(s):  
Michael W. Lema ◽  
Arnold Brown ◽  
Charles A. Butler ◽  
Paul S. Hoffman

The heat-shock response of Legionella pneumophila was examined by radiolabelling bacterial cell proteins with [35S]methionine following a temperature shift from 30 to 42 °C. Five heat-shock proteins were identified as having molecular masses of 17, 60, 70, 78, and 85 kilodaltons (kDa). The 85- and 60-kDa proteins were equally distributed between supernatant and pellet fractions following ultracentrifugation at 100 000 × g, the 70- and 78-kDa proteins were found primarily in the supernatant, and the 17-kDa protein was found primarily in the pellet. Synthesis of subsets of the heat-shock proteins could be stimulated by novobiocin, patulin, or puromycin. Ethanol, an effector of the heat-shock response in other microorganisms, had little effect on L. pneumophila, even at the highest concentration tolerated by the bacterial cells (1.9%). Finally, the 60-kDa heat-shock protein of L. pneumophila was immunologically cross-reactive with a polyclonal antibody prepared to the Escherichia coli groEL protein. However, a mouse monoclonal antibody reactive with the 60-kDa protein of all legionellae tested did not cross-react with the E. coli groEL protein, suggesting that the Legionella 60-kDa protein contains common and unique epitopes.


Sign in / Sign up

Export Citation Format

Share Document